W. Lohmann

We present results on a high statistics study of the proton structure functions F2(x, Q2) and R=σL/σT measured in deep inelastic scattering of muons on a hydrogen target. The analysis is based on 1.8 × 106 events after all cuts, recorded at beam energies of 100, 120, 200 and 280 GeV and covering a kinematic range 0.06 ⩽ x ⩽ 0.80 and 7 GeV2 ⩽Q2 ⩽260 GeV2. At small x, we find R to be different from zero in agreement with predictions of perturbative QCD.

This Conceptual Design Report describes LUXE (Laser Und XFEL Experiment), an experimental campaign that aims to combine the high-quality and high-energy electron beam of the European XFEL with a powerful laser to explore the uncharted terrain of quantum electrodynamics characterised by both high energy and high intensity. We will reach this hitherto inaccessible regime of quantum physics by analysing high-energy electron-photon and photon-photon interactions in the extreme environment provided by an intense laser focus. The physics background and its relevance are presented in the science case which in turn leads to, and justifies, the ensuing plan for all aspects of the experiment: Our choice of experimental parameters allows (i) effective field strengths to be probed at and beyond the Schwinger limit and (ii) a precision to be achieved that permits a detailed comparison of the measured data with calculations. In addition, the high photon flux predicted will enable a sensitive search for new physics beyond the Standard Model. The initial phase of the experiment will employ an existing 40 TW laser, whereas the second phase will utilise an upgraded laser power of 350 TW. All expectations regarding the performance of the experimental set-up as well as the expected physics results are based on detailed numerical simulations throughout.

We present results on a high statistics study of the nucleon structure functions F2(x, Q2) and R=σL/σT measured in deep inelastic scattering of muons on a deuterium target. The analysis is based on 8×105 events after all cuts, recorded at beam energies of 120, 200 and 280 GeV in the kinematic range 0.06⩽ × ⩽0.80 and 8GeV2⩽Q2⩽260GeV2. Scaling violations observed in the data are in agreement with predictions of perturbative QCD and allow to determine the QCD mass scale parameter Λ.

The design and construction of the silicon strip microvertex detector (SMD) of the L3 experiment at LEP are described. We present the sensors, readout electronics, data acquisition system, mechanical assembly and support, displacement monitoring systems and radiation monitoring system of the recently installed double-sided, double-layered SMD. This detector utilizes novel and sophisticated techniques for its readout.

New data is presented on the ratios of structure functions F2(x, Q2) measured in deep inelastic muon scattering with deuterium, nitrogen, and iron targets. The existence of nuclear effects at large Q2 is confirmed with improved systematic accuracy. The ratio F2Fe(x)F2D2(x) covers the range 0.20 ⩽ x ⩽ 0.70 and is in agreement with earlier measurements. The ratio F2N2(x)/F2D2(x) is measured over the range 0.08 ⩽ x ⩽ 0.70 and is compatible with unity below x = 0.3.

New Results are presented on nuclear effects in deep inelastic muon scattering on deuterium and iron targets at large Q2. The ratio FFe2(x)FD22(x) measured in the kinematic range 0.06⩽x⩽0.70, 14GeV2⩽Q2⩽70 GeV2 is in good agreement with earlier measurements in the region of x > 0.25. At lower x, the structure function ratio exhibits an enhancement of ≈5%.

Exclusive rho^0 electroproduction at HERA has been studied with the ZEUS detector using 120 pb^{-1} of integrated luminosity collected during 1996-2000. The analysis was carried out in the kinematic range of photon virtuality 2 < Q^2 < 160 GeV$^2, and gamma^* p centre-of-mass energy 32 < W < 180 GeV. The results include the Q^2 and W dependence of the gamma^* p --> rho^0 p cross section and the distribution of the squared-four-momentum transfer to the proton. The helicity analysis of the decay-matrix elements of the rho^0 was used to study the ratio of the gamma^* p cross section for longitudinal and transverse photon as a function of Q^2 and W. Finally, an effective Pomeron trajectory was extracted. The results are compared to various theoretical predictions.

High statistics data on the structure functions F2 of the proton and the deutron measured with the same apparatus in deep inelastic muon scattering are used to study the ratio of structure functions of neutron and proton F2n/F2p and their difference F2p-F2n. Both measurements are consistent with predictions of the quark-parton model and of QCD.

The reductone ascorbic acid, present in the crystalline lens in concentrations higher than those of glucose, is capable of undergoing nonenzymatic "browning" in the presence of lenticular proteins. We studied the nonenzymatic browning with ascorbate in model systems employing bovine serum albumin and lens crystallins. When bovine serum albumin, alpha-crystallin, or gamma-crystallin was incubated with [14C]ascorbic acid, the formation of yellow and then brown condensation products appeared to correlate with increasing protein-associated radioactivity. The fluorescence spectrum of these products was similar to that of homogenates of human cataractous lenses. We suggest that the nonenzymatic reaction of lens crystallins with ascorbic acid may contribute, at least in part, to the color changes of aging lenses and to the physical lenticular deterioration leading to senile cataract. High dietary intake of ascorbic acid did not affect the fluorescence spectrum of murine lenses; thus, we assume that the speed and extent of the lenticular browning reactions must depend on a deterioration of other factors of the multicomponent antioxidant system of the eye.

We present results from a high statistics study of the nucleon structure function F2(x,Q2) measured in deep inelastic scattering of muons on carbon in the kinematic range 0.25⩽x⩽0.80 and Q2⩾25 GeV2. The analysis is based on 1.5×106 reconstructed events recorded at beam energies of 120, 200 and 280 GeV. R=σL/σT is found to be independent of x in the range 0.25⩽x⩽0.07 and 40 GeV2⩽Q2⩽200 GeV2 with a mean value R=0.015±0.013 (stat) ±0.026 (syst.).

A non-invasive and non-destructive fluorescence technique developed recently for an in situ detection of melanomas has been applied for determining in vitro dysplasia and invasive carcinomas in the cervix uteri. The cervices uteri exhibit a fluorescence band with a peak at about 475 nm if excited with 365 nm. The fluorescence intensity increases concomitantly with the degree of dysplasia, ranging from 30 counts/100 ms (healthy) to approximately 200 counts per 100 ms (CIN 3). At the rim of a malignancy, the intensity is 250 counts/100 ms and higher and decreases towards the healthy region. In the tumor region, the intensity is about zero or very small, at the most. The naturally occurring chromophore being responsible for the fluorescence observed seems to be NADH.

The biological efficacy of vitamin C depends on its redox abilities as given by the relations between ascorbic acid, semidehydroascorbic acid, and dehydroascorbic acid. It is shown by means of proton magnetic resonance spectroscopy that the enzymatic (by ascorbate oxidase) as well as non-enzymatic (by iodine) oxidation of ascorbic acid is, in principle, reversible despite the hydration and structural changes during the formation of dehydroascorbic acid. The strong redox activity of semidehydroascorbic acid which results in a fast disproportionation to ascorbic acid and dehydroascorbic acid is inferred from an inversion of the electrochemical potentials of the vitamin C redox system. The capacity of this is maintained by a fast reduction of dehydroascorbic acid e.g. by reduced glutathione, preventing its delactonization and further degradation.

The application of diamond for the detection of charged particles in atomic, nuclear and high-energy physics experiments is described. We compare the properties of three undoped diamond types, all of them produced by Chemical Vapor Deposition (CVD), in particular homoepitaxial single-crystal CVD Diamond (scCVDD), polycrystalline CVD Diamond (pcCVDD) grown on silicon, and CVD Diamond on Iridium (DoI) grown on the multi-layer substrate Ir/YSZ/Si001. The characteristics of the transient current (TC) signals generated from 241Am-α-particles in the samples are exploited to evaluate the potential of the diamond crystals for particle timing and spectroscopy applications. The TC technique (TCT) results are correlated to the dark conductivity and the structural defects of the bulk materials as well as to the morphology and roughness of the diamond surfaces. The deterioration of the sensors performance after heavy irradiations with 26 MeV protons, 20 MeV neutrons, and 10 MeV electrons is discussed by means of charge-collection efficiency results, TC technique, and optical absorption spectroscopy (OAS). The important role of the diamond signal processing is underlined, which influences both the quality of the CVDD characterization data as well as the in-beam performance of the diamond sensors.

Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10−3 and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised.

Scaling violations in the proton structure function F2(x, Q2) measured with high statistics in deep inelastic scattering of muons on a hydrogen target are compared to predictions of perturbative QCD. Excellent agreement is observed with numerical solutions of the evolution equations in leading and next-to-leading order. The QCD mass scale parameter Λ is determined from these data both in a flavour nonsinglet approximation and with a complete flavour singlet and nonsinglet treatment. An estimate of the gluon distribution in the proton is given.

The lens and cornea are transparent and usually avascular. Controlling nutrient supply while maintaining transparency is a physiological challenge for both tissues. During sleep and with contact lens wear the endothelial layer of the cornea may become hypoxic, compromising its ability to maintain corneal transparency. The mechanism responsible for establishing the avascular nature of the corneal stroma is unknown. In several pathological conditions, the stroma can be invaded by abnormal, leaky vessels, leading to opacification. Several molecules that are likely to help maintain the avascular nature of the corneal stroma have been identified, although their relative contributions remain to be demonstrated. The mammalian lens is surrounded by capillaries early in life. After the fetal vasculature regresses, the lens resides in a hypoxic environment. Hypoxia is likely to be required to maintain lens transparency. The vitreous body may help to maintain the low oxygen level around the lens. The hypothesis is presented that many aspects of the aging of the lens, including increased hardening, loss of accommodation (presbyopia), and opacification of the lens nucleus, are caused by exposure to oxygen. Testing this hypothesis may lead to prevention for nuclear cataract and insight into the mechanisms of lens aging. Although they are both transparent, corneal pathology is associated with an insufficient supply of oxygen, while lens pathology may involve excessive exposure to oxygen.

The production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q 2 < 1000 GeV2 using an integrated luminosity of 354 pb−1. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of Q 2, Bjorken x, jet trans- verse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of x and Q 2. The running beauty-quark mass, m b at the scale m b , was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be m b (m b ) = 4.07 ± 0.14 (fit) − 0.07 + 0.01 (mod.) − 0.00 + 0.05 (param.) − 0.05 + 0.08 (theo.) GeV.

The reduced cross sections for $e^{+}p$ deep inelastic scattering have been measured with the ZEUS detector at HERA at three different centre-of-mass energies, $318$, $251$ and $225$ GeV. The cross sections, measured double differentially in Bjorken $x$ and the virtuality, $Q^2$, were obtained in the region $0.13\ \leq\ y\ \leq\ 0.75$, where $y$ denotes the inelasticity and $5\ \leq\ Q^2\ \leq\ 110$ GeV$^2$. The proton structure functions $F_2$ and $F_L$ were extracted from the measured cross sections.

Background: Second primaries in the upper aerodigestive tract (UADT) are increasingly related to bad prognosis. So early detection of small cancer foci is required to improve the survival rate. Here, autofluorescence (AF) might become useful as in vivo biochemical changes of cancer metabolism can be shown by fluorescence.Material: For more exact data on AF in cancerous lesions 32 cancer specimens of the UADT and 57 specimens of normal oral mucosa as a control group were examined by using autofluorescent microscopy and spectroscopy, the tissue being activated with light at 365 ran wavelength. Video-controlled in vivo fluorescence examinations in field cancerisation of the UADT were also investigated and compared with pathohistological findings.Results: The intensity of AF of the connective tissue was observed to increase at the tumour border. Contrary to results in the literature, no homogeneous fluorescence gradient could be proved between marginal epithelium and the tumour itself. The brightly shining submucosal elastic fibres allowed fluorescent spectroscopic detection of the tumour margins in vitro in 71%. Even small precancerous lesions were traced in vivo mainly by keratinization when using the autofluorescence diagnostic imaging system.Contusions: Our examination proved a multi-factorial genesis of autofluorescence with strong inter-individual variations. Preliminary clinical examination showed that this method can be applied as an additional tool for early detection of cancerous lesions in the UADT.

The construction and performance of two large coaxial cylindrical multiwire proportional chambers with cathode readout, denoted as Z-detector, forming the outer part of the L3 central tracking detector, are described. Three self-supporting cylinders of about 1 m length and 1 m diameter, constructed as a sandwich of Kapton foil and foam, form the mechanical frame. In each chamber one cathode layer is subdivided into helical strips and the other one in rings. The readout of the charges induced on the cathode strips provides the avalanche position along the beam (z) direction. The detector has been running in the L3 experiment at LEP for nearly two years. The resolution of the z-measurement is 320 μm, the double track resolution is 10 mm. The efficiency of each chamber is 96%.

The L3 detector at the CERN electron–positron collider, LEP, has been employed for the study of cosmic ray muons. The muon spectrometer of L3 consists of a set of high-precision drift chambers installed inside a magnet with a volume of about 1000m3 and a field of 0.5T. Muon momenta are measured with a resolution of a few percent at 50GeV. The detector is located under 30m of overburden. A scintillator air shower array of 54m by 30m is installed on the roof of the surface hall above L3 in order to estimate the energy and the core position of the shower associated with a sample of detected muons. Thanks to the unique properties of the L3+C detector, muon research topics relevant to various current problems in cosmic ray and particle astrophysics can be studied.

The four O-H bands of ascorbic acid could be assigned by means of infrared investigations. It could be shown by electron spin resonance and nuclear magnetic resonance measurements that the radical sodium ascorbate is formed by a cyclic side-chain structure resulting in a loss of C(6)-OH and C(3)-OH. The C(2) = C(3) double bond is still maintained as could be shown by infrared and ultraviolet absorption spectroscopy. In the case of complete oxidation of ascorbic acid to dehydroascorbic acid, C(6)-OH is reestablished (indicating the reopening of the furanoid ring), while C(2)-OH as well as the C(2) = C(3) double bond have disappeared due to the deprotonation of C(2)-OH and C(3)-OH. In the case of isoascorbic acid and its radical potassium isoascorbate similar results are obtained with one distinct difference: in the case of isoascorbic acid, C(2)-OH does not appear while C(3)-OH exhibits a shoulder.

Scaling violations in the nucleon structure function F2(x,Q2) measured with high statistics in deep inelastic scattering of muons on a carbon target are compared to predictions of perturbative QCD. Excellent agreement is observed with numerical solutions of the Altarelli-Parisi evolution equations over the entire x and Q2 range of data. In a next-to-leading order nonsinglet approximation, the QCD mass scale parameter ΛMS is determined to be 230±20(stat.)±60(syst.) MeV. A singlet to the data favours a soft gluon distribution.

The concentration dependence of the cubic to tetragonal phase transformation of the CeAgxIn1-x intermetallics is investigated in the silver-rich concentration range by means of resistivity measurements. The measurements show that the concentration dependence of the transition temperatures follows strictly the predictions of the Jahn-Teller-like band model as long as the transition temperatures are above 15K. For the compounds having very low indium contents and for CeAg, another type of phase transformation at about 15K is indicated by the resistivity measurements. The magnetic ordering of the compounds investigated causes a resistivity hysteresis. The magnetic ordering of the compounds investigated causes a resistivity hysteresis. The magnetic ordering temperature, which is about 6K for CeAg, increases with the indium content and supports the assumption that the 4f conduction electron exchange is enhanced by the Fermi energy entering a high density of states peak originating from narrow d type electron bands.

A compact and finely grained sandwich calorimeter is designed to instrument the very forward region of a detector at a future e+e− collider. The calorimeter will be exposed to low energy e+e− pairs originating from beamstrahlung, resulting in absorbed doses of about one MGy per year. GaAs pad sensors interleaved with tungsten absorber plates are considered as an option for this calorimeter. Several Cr-doped GaAs sensor prototypes were produced and irradiated with 8.5–10 MeV electrons up to a dose of 1.5 MGy. The sensor performance was measured as a function of the absorbed dose.

The luminosity in the ZEUS detector was measured using photons from electron bremsstrahlung off protons. In 2001 the HERA collider was upgraded for operation at higher luminosity. At the same time the luminosity-measuring system of the ZEUS experiment was modified to tackle the expected higher photon rate and synchrotron radiation. The existing lead-scintillator calorimeter was equipped with radiation hard scintillator tiles and shielded against synchrotron radiation. In addition, a magnetic spectrometer was installed to measure the luminosity independently using photons converted in the beam-pipe exit window. The redundancy provided a reliable and robust luminosity determination with a systematic uncertainty of 1.7%. The experimental setup, the techniques used for luminosity determination and the estimate of the systematic uncertainty are reported.

The CMS Beam Conditions and Radiation Monitoring System, BRM, will support beam tuning, protect the CMS detector from adverse beam conditions, and measure the accumulated dose close to or inside all sub-detectors. It is composed of different sub-systems measuring either the particle flux near the beam pipe with time resolution between nano- and microseconds or the integrated dose over longer time intervals. This paper presents the Fast Beam Conditions Monitor, BCM1F, which is designed for fast flux monitoring measuring both beam halo and collision products. BCM1F is located inside the CMS pixel detector volume close to the beam-pipe. It uses sCVD diamond sensors and radiation hard front-end electronics, along with an analog optical readout of the signals. The commissioning of the system and its successful operation during the first beams of the LHC are described.

The development of CVD grown single-crystal Diamond-on-Iridium (DOI) sensors for charged-particle detection in hadrons and nuclei physics research is reviewed. A variety of samples grown at the University of Augsburg has been investigated with α and β sources in the laboratory, swift ions from the heavy-ion synchrotron SIS in Darmstadt, and relativistic protons from the COoler-SYnchrotron COSY in Jülich. The results obtained by means of I-E(V) studies, transient-current techniques (TCT), α-spectroscopy, and heavy-ion time-of-flight (ToF) measurements are compared to those of commercially available polycrystalline and homoepitaxial single crystal CVD diamond sensors of electronic grade quality. In many aspects, the performance of DOI sensors was found quite similar to that of homoepitaxial counters, and in any case far superior to that of polycrystalline detectors. Under single-carrier drift conditions, the CCE and energy resolution (δE/E) for holes reached levels CCEh > 95% and δE/Eh ~ 0.3%, respectively, which correspond to values of the Schubweg wh,e well above the detector thickness. In contrast, the CCEe for electrons was typically lower than ~40%, leading to appreciable reduction of the detection efficiency in the dual-carrier drift mode (CCE ~ 60%), which characterizes the experiments with swift heavy ions and high-energy particles. We measured transport parameters comparable to those of homoepitaxial devices: μ0h ~ 3080–1756 and μ0e ~ 2276–1150 cm2/Vs, vsath ~ (1.7–1.4) ∗ 107 and vsate ~ (1.5–1.0) ∗ 107 cm/s, as well as intrinsic time resolutions σi ~ 15 ps. It is shown, that substantial improvements have been achieved in recent years, albeit reproducibility and the understanding of the reduced electron collection remain challenging issues. Prime novelty: Comprehensive electrical characterization of intrinsic single-crystal CVD Diamond-On-Iridium sensors produced at the University of Augsburg and their classification into the range of commercial electronic grade polycrystalline and homoepitaxial diamond sensors supplied by Element Six.

The very forward region of a detector at a linear e/sup +/e/sup -/ collider is a particularly challenging area for instrumentation. In the TESLA detector, two calorimeters, BeamCal (Beam Calorimeter) and LumiCal (Luminosity Calorimeter) are planned. The BeamCal is positioned just adjacent to the beampipe. It will be hit by beamstrahlung remnants giving a deposition of several tens of TeV per bunch crossing. The distribution of this energy will be measured to assist in tuning the beams. Single high-energy electrons will be identified and measured. High-energy electron identification is particularly important to veto backgrounds to new particle searches. Several technological options for BeamCal are discussed. Monte Carlo simulations are presented for a diamond/tungsten sandwich structure and compared to results obtained for a heavy element crystal calorimeter. First, tests of sensors are described. The LumiCal will measure larger polar angles than the BeamCal. It will provide a high-precision (O(10/sup -4/)) luminosity measurement from Bhabha scattering. Monte Carlo simulations to optimize the shape and the structure of the calorimeter are presented.

Ascorbic acid is capable of forming an ionic bond with biological molecules at physiologic pH. The influence of such a bond on the reactivity of the molecular complex should be considerable because the bond does not directly affect the functional site of the ascorbate. It must bring about local alteration of the redox potential and accelerate charge transfer reactions. Facilitation of these properties may be one of the biological functions of ascorbic acid.

Abstract The Beam Condition Monitor (BCM) of the CMS detector at the LHC is a protection device similar to the LHC Beam Loss Monitor system. While the electronics used is the same, poly-crystalline Chemical Vapor Deposition (pCVD) diamonds are used instead of ionization chambers as the BCM sensor material. The main purpose of the system is the protection of the silicon Pixel and Strip tracking detectors by inducing a beam dump, if the beam losses are too high in the CMS detector. By comparing the detector current with the instantaneous luminosity, the BCM detector efficiency can be monitored. The number of radiation-induced defects in the diamond, reduces the charge collection distance, and hence lowers the signal. The number of these induced defects can be simulated using the FLUKA Monte Carlo simulation. The cross-section for creating defects increases with decreasing energies of the impinging particles. This explains, why diamond sensors mounted close to heavy calorimeters experience more radiation damage, because of the high number of low energy neutrons in these regions. The signal decrease was stronger than expected from the number of simulated defects. Here polarization from trapped charge carriers in the defects is a likely candidate for explaining the difference, as suggested by Transient Current Technique (TCT) measurements. A single-crystalline (sCVD) diamond sensor shows a faster relative signal decrease than a pCVD sensor mounted at the same location. This is expected, since the relative increase in the number of defects is larger in sCVD than in pCVD sensors.

The production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q 2 < 1000 GeV2 using an integrated luminosity of 354 pb−1. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of Q 2, Bjorken x, jet trans- verse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of x and Q 2. The running beauty-quark mass, m b at the scale m b , was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be m b (m b ) = 4.07 ± 0.14 (fit) − 0.07 + 0.01 (mod.) − 0.00 + 0.05 (param.) − 0.05 + 0.08 (theo.) GeV.

Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e− collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

Abstract Dehydro-ʟ-ascorbic acid, the oxidation product of L-ascorbic acid, is unstable in aqueous solution and decomposed by a hydrolytic disruption of its ring structure to 2,3-diketo-ʟ-gulonic acid. It is shown by means of UV, 1 H-, and 13 C-NMR spectroscopy that after decarboxylation 3,4,5-trihydroxy-2-keto-ʟ-valeraldehyde, an α-ketoaldehyde, is formed. This substance is oxidized further to ʟ-erythroascorbic acid, coupled with a reduction of 2,3-diketo-ʟ-gulonic acid to L-ascorbic acid.

Polycrystalline artificial diamond produced by chemical vapor deposition (pCVD) is a possible sensor material for the beam calorimeter of the ILC. The requirements are linearity over a large range of flux and radiation hardness against a total ionizing dose of several MGy per year of operation. A hadron test beam at the CERN PS was used to study the linearity of the response of pCVD sensors. An electron test beam at the S-DALINAC was used to measure the charge collection distance (CCD) as a function of the absorbed dose up to several MGy. Current-voltage characteristics of these sensors were measured before and after the irradiation as well as the dependence of the CCD on the applied electric field before and after the irradiation.

A bstract A search for new top quark interactions is performed within the framework of an effective field theory using the associated production of either one or two top quarks with a Z boson in multilepton final states. The data sample corresponds to an integrated luminosity of 138 fb − 1 of proton-proton collisions at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 13 TeV collected by the CMS experiment at the LHC. Five dimension-six operators modifying the electroweak interactions of the top quark are considered. Novel machine-learning techniques are used to enhance the sensitivity to effects arising from these operators. Distributions used for the signal extraction are parameterized in terms of Wilson coefficients describing the interaction strengths of the operators. All five Wilson coefficients are simultaneously fit to data and 95% confidence level intervals are computed. All results are consistent with the SM expectations.

Data from deep inelastic scattering of 200 GeV muons on a carbon target with squared four-momentum transfer 52 GeV2≤Q 2≤200 GeV2 were analysed in the region of the Bjorken variable close tox=1, which is the kinematic limit for scattering on a free nucleon. At this value ofx, the carbon structure function is found to beF 2 ≈1.2·10−4. Thex dependence of the structure function forx>0.8 is well described by an exponentialF 2 ∞exp(−sx) withs=16.5±0.6.

Results on K∗(890) production in K−p → NKπ reactions at 16 GeV/c are presented. Total cross sections, differential cross sections and density matrix elements are determined. It is found that: (i) The cross section for K∗−(890) p is consistent with containing two components, one due to natural parity exchange, falling slowly with increasing energy, the other, due to unnatural parity exchange, vanishing rapidly with increasing energy. For K∗o(890)n, the cross section decreases steadily as the energy increases. (ii) Natural spin-parity exchange dominates in the K∗−(890) p channel, the unnatural exchange contribution being approximately (5±4)%. In K∗o(890)n, natural spin-parity exchange is only about (30±10)%. (iii) The reacton K−p → K∗−(890)p is dominated (95±5)% by isoscalar exchange. (iv) The effective trajectory involved in the I = 0 natural parity exchange is consistent with the ω-f trajectory. (v) Interference terms between exchanges with positive (f, πo,…) and negative (ϱo, ω,…) C-conjugation amount to (23±12) μb at 16 GeV/c.

A prototype of a luminometer, designed for a future $$e^+e^-$$ collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Molière radius has been determined to be 24.0 ± 0.6 (stat.) ± 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.

The photoproduction of isolated photons, both inclusive and together with a jet, has been measured with the ZEUS detector at HERA using an integrated luminosity of 374pb−1. Differential cross sections are presented in the isolated-photon transverse-energy and pseudorapidity ranges 6<ETγ<15GeV and −0.7<ηγ<0.9, and for jet transverse-energy and pseudorapidity ranges 4<ETjet<35GeV and −1.5<ηjet<1.8, for exchanged-photon virtualities Q2<1GeV2. Differential cross sections are also presented for inclusive isolated-photon production as functions of the transverse energy and pseudorapidity of the photon. Higher-order theoretical calculations are compared to the results.

Annals of the New York Academy of SciencesVolume 498, Issue 1 p. 402-417 Ascorbic Acid and Cancera W. LOHMANN, W. LOHMANN Institut für Biophysik Universität Giessen Giessen, Federal Republic of GermanySearch for more papers by this author W. LOHMANN, W. LOHMANN Institut für Biophysik Universität Giessen Giessen, Federal Republic of GermanySearch for more papers by this author First published: July 1987 https://doi.org/10.1111/j.1749-6632.1987.tb23777.xCitations: 13 a This work was supported in part by grants from the Bundesministerium für Forschung und Technologie (nos. 01Z0014/9 and 01Z0062/8) and from the Fonds der Chemischen Industrie. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume498, Issue1Third Conference on Vitamin CJuly 1987Pages 402-417 RelatedInformation

In recent years serotonin (5-hydroxytryptamine) has aroused considerable interest among radiobiologists because of its effectiveness in radioprotection, an effect discovered concurrently by Gray et al. (1) and Bacq et al. (2) in rats and mice. Subsequent investigations showed that serotonin also protected in other systems (3). Its dose-reduction factor was found to be larger than that of the known SH agents. Several hypotheses have been proposed to explain the radioprotective mechanism of serotonin. Since serotonin demonstrates pronounced pharmacological properties, its radioprotective action in vivo was thought to involve vasoconstriction and, consequently, tissue hypoxia (1, 4-8). Free radical scavenging (9) and interference with biochemical reactions (10, 11) were discussed as other possibilities. All the hypotheses suggested, however, have been questioned, and none seems to give an unambiguous explanation for the effects observed. Recently, Dukor (3) was able to show that serotonin protection cannot be attributed to hypoxia or free radical scavenging. He proposed instead that complex formation between the radiosensitive target and the protector molecule might be responsible for the observed protection. Because of the importance of serotonin in radiobiology, it is obviously of interest to investigate its mode of action, particularly if such studies lead to the discovery of substances having greater radioprotective abilities but with less pharmacodynamic side effects. Since a number of enzymes have metal ions as part of their active site, one useful line of inquiry is the investigation of complex formation between

Der Glyzerin-Schutz der Zellen gegen Schäden beim Gefrieren und Auftauen wird mittels einer Komplexbildung zwischen Glyzerin und Metallionen erklärt. Elektron-Spin-Resonanz-Untersuchungen bestätigen die Bildung eines solchen Komplexes.

Recently we have shown (1) that glycerol exhibits an excellent radioprotective effect with catalase. As a possible explanation for this effect we proposed that a complex is formed between iron atoms in the macromolecule and the glycerol. From the work of Bomberg and Luse (2) and of Sutton (3) it is known that the iron atoms are almost exclusively responsible for the biological activity of the enzyme. Baxendale (4) has reported that metal ions such as Fe3+ and Cu2+ are capable of undergoing reactions with the reactive radicals formed in aqueous solutions by X-irradiation. Then, metal ions added to the catalase solution should provide a radioprotective effect. This communication reports results obtained concerning the radiation response of catalase when low concentrations of Fe3+, Mn2+, and Cu2+ are used: A possible protective mechanism is discussed; however, it need not be an exclusive one. Parts of the results have been reported previously (5).

A new design of a detector plane of sub-millimetre thickness for an electromagnetic sampling calorimeter is presented. It is intended to be used in the luminometers LumiCal and BeamCal in future linear e $$^{+}$$ e $$^{-}$$ collider experiments. The detector planes were produced utilising novel connectivity scheme technologies. They were installed in a compact prototype of the calorimeter and tested at DESY with an electron beam of energy 1–5 GeV. The performance of a prototype of a compact LumiCal comprising eight detector planes was studied. The effective Molière radius at 5 GeV was determined to be (8.1 ± 0.1 (stat) ± 0.3 (syst)) mm, a value well reproduced by the Monte Carlo (MC) simulation (8.4 ± 0.1) mm. The dependence of the effective Molière radius on the electron energy in the range 1–5 GeV was also studied. Good agreement was obtained between data and MC simulation.

Abstract Durch Reaktion von SiCl 4 mit HCHO und γ‐Al 2 O 3 als Katalysator werden nach die Chlorsilane SiH 3 Cl und SiH 2 Cl 2 dargestellt. Bei 400° und einem Verhältnis von SiCl 4 :HCHO = 1:3 wird fast quantitativer Umsatz von SiCl 4 erzielt und dabei eine Ausbeute von 86% SiH 3 Cl und 13,2% SiH 2 Cl 2 erhalten. Nimmt man weniger HCHO, dann Steigt der Anteil von SiH 2 Cl 2 im Reaktionsprodukt, während der SiCl 4 ‐Umsatz sinkt.

The Pixel Luminosity Telescope is a silicon pixel detector dedicated to luminosity measurement at the CMS experiment at the LHC. It is located approximately 1.75 m from the interaction point and arranged into 16 "telescopes", with eight telescopes installed around the beam pipe at either end of the detector and each telescope composed of three individual silicon sensor planes. The per-bunch instantaneous luminosity is measured by counting events where all three planes in the telescope register a hit, using a special readout at the full LHC bunch-crossing rate of 40 MHz. The full pixel information is read out at a lower rate and can be used to determine calibrations, corrections, and systematic uncertainties for the online and offline measurements. This paper details the commissioning, operational history, and performance of the detector during Run 2 (2015-18) of the LHC, as well as preparations for Run 3, which will begin in 2022.

This Technical Design Report presents a detailed description of all aspects of the LUXE (Laser Und XFEL Experiment), an experiment that will combine the high-quality and high-energy electron beam of the European XFEL with a high-intensity laser, to explore the uncharted terrain of strong-field quantum electrodynamics characterised by both high energy and high intensity, reaching the Schwinger field and beyond. The further implications for the search of physics beyond the Standard Model are also discussed.

By comparing proton and electron spin resonance spec­tra of twofold and single oxidized ascorbate and acetylated derivatives therefrom it can be concluded that semidehy- droascorbate as well as dehydroascorbate are of bicyclic structure due to the formation of a furanose ring of their side chain.

A strong negative transverse polarization Pz is found for forward produced lambdas observed in 10 and 16 GeV/c K−p interactions. This indicates that exchanges of natural spin-parity are dominant in the production process. Using the polarization results, the dσdu′ distributions for natural and unnatural spin-parity exchanges are derived. For unnatural exchanges, a dip is observed at u′≅0.3 GeV2, which can be explained as a nonsense-wrong-signature zero of the Nβ trajectory. The value of Pz for forward producted lambdas is constant with energy. This is in agreement with the triple-Regge model prediction, as is the fact that Pz is constant as a function of M2s. The two non-transverse polarization components, Px and Py, have been measured and are found to be consistent with zero for all x values, unlike Pz.

The interaction between lyophilized samples of ascorbic acid and some copper proteins (ceruloplasmin, cytochrome-c-oxidase, ascorbate-oxidase) has been investigated by means of ESR spectroscopy. The spectra obtained are identical to the one obtained with leukemic blood. The consequences of this for the molecular events occurring in cancer are discussed. The model proposed can explain the experimental findings reported thus far (such as change in spin concentration with the development of cancer, the presence of a high concentration of antioxidants etc.) as well as reconsile the two existing and seemingly contradictory hypothesis. Possible implications for lipid peroxidation and for the respiratory process are discussed.

The beam delivery system for the linear collider focuses beams to nanometer sizes at its interaction point, collimates the beam halo to provide acceptable background in the detector and has a provision for state-of-the art beam instrumentation in order to reach the ILC's physics goals. This paper describes the design details and status of the baseline configuration considered for the reference design and also lists alternatives.

The neutral current ${e}^{\ifmmode\pm\else\textpm\fi{}}p$ cross section has been measured up to values of Bjorken $x\ensuremath{\cong}1$ with the ZEUS detector at HERA using an integrated luminosity of $187\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{\ensuremath{-}}p$ and $142\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}p$ collisions at $\sqrt{s}=318\text{ }\text{ }\mathrm{GeV}$. Differential cross sections in $x$ and ${Q}^{2}$, the exchanged boson virtuality, are presented for ${Q}^{2}\ensuremath{\ge}725\text{ }\text{ }{\mathrm{GeV}}^{2}$. An improved reconstruction method and greatly increased amount of data allows a finer binning in the high-$x$ region of the neutral current cross section and leads to a measurement with much improved precision compared to a similar earlier analysis. The measurements are compared to Standard Model expectations based on a variety of recent parton distribution functions.

Electron spin resonance (EPR) spectra demonstrate the formation of a complex between the ascorbate ion and disulfides such as oxidized glutathione, cystine, gamma globulin, bovine serum albumin, 4-4′ dithiopyridine, and dithiobutyric acid. However, except in the case of 4-4′ dithiopyridine. ascorbic acid (AH 2 ) is not capable of reducing the disulfide bond in these compounds. These results can be explained in terms of the redox potential of ascorbic acid and its radical semidehydroascorbic acid (SDA). These compounds can reduce the S-S bond of 4-4′ dithiopyridine, the redox potential of which is E′ = -0. 1 V and, thus, more positive than the ones deter­mined for the ascorbic acid system.

It could be shown by the reduction of the spin label (1,14) located within DPPC vesicles, that Na-ascorbate and K-isoascorbate can permeate membranes. At physiologic pH value, these two compounds exist as electroneutral radicals with a cyclic side chain structure. Ascorbic acid and isoascorbic acid, on the contrary, can hardly permeate such an artificial membrane. Since the radical will cause lipid peroxidation, it must be modified prior to permeation. This can be done by GSH which changes the radical state but maintains the electroneutral bicyclic configuration.

The L3 central tracking detector has been in operation since the start-up of LEP (Large Electron Positron collider) in 1989. This detector consists of a Time Expansion Chamber (TEC), a layer of Plastic Scintillating Fibers and a Z-chamber. The TEC gives a high spatial resolution and an excellent multi-track reconstruction capability. The fibers are designed to calibrate the drift velocity with high precision. The Z-Chamber provides TEC with accurate information about the z-coordinates of the tracks. A description of the design and the infrastructure of these three detectors, including the readout and data acquisition system, is given. The performance of the detectors during the 1990 and 1991 LEP running periods is presented.

Abstract The ultraviolet absorption spectra of uracil and its 5-halogenated derivatives have been in ­ vestigated in regard to the electron attracting properties of the substituents. It could be shown that the position of the two absorption bands is proportional to the inverse of the electronegativity; the extinction coefficients are a linear function of the electron affinities. In this way, the red shift obtained upon substitution with halogens can be explained. Also, the decrease in absorbance of the absorption bands at λ &gt; 250 nm, occuring concomitant­ ly, is understandable. The increase in absorbance with increasing electron affinity, as observed in the case of the absorption bands at λ &lt; 250 nm, might question the assumption that this band is due to a higher pi -pi* excitation

Es wurden die ESR-, NMR- und die optischen Absorptionsspektren für Fe3+, Cu2+ und Mn2+ in Wasser- oder Glycerollösungen bestimmt. Die untersuchten Metallionen bilden einen Komplex mit Glycerol.

The CMS beam and radiation monitoring subsystem BCM1F (Fast Beam Condition Monitor) consists of 8 individual diamond sensors situated around the beam pipe within the pixel detector volume, for the purpose of fast bunch-by-bunch monitoring of beam background and collision products. In addition, effort is ongoing to use BCM1F as an online luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. A report is given on the performance of BCM1F during LHC run I, including results of the van der Meer scan and on-line luminosity monitoring done in 2012. In order to match the requirements due to higher luminosity and 25 ns bunch spacing, several changes to the system must be implemented during the upcoming shutdown, including upgraded electronics and precise gain monitoring. First results from Run II preparation are shown.

Abstract Abstract Commercial AlMg- and AlMgSi-alloys were irradiated with medium energy (600-800 MeV) protons to a nominal fluence of 3.2 × 1024 p/m2 which yields by calculation a displacement damage of 0.2 dpa and helium and hydrogen generation of 67 and 275 appm, respectively. Post-irradiation tensile testing revealed a very marked degree of irradiation-induced softening in the cold-worked AlMg-alloy as well as in the precipitation-hardened AlMgSi-alloy. The TEM examination of the irradiated specimens showed that neither the cold-work microstructure in the AlMg-alloy nor the G.P. zone type precipitates in the AlMgSi-alloy survive under the irradiation conditions used in the present experiment. Results of complimentary investigations (i.e., hardness measurements, optical microscopy and SEM-fractography) are also presented.

Abstract The interaction of Cu 2+ with isonicotinic acid hydrazide (INH) and some of its derivatives has been investigated by means of electron spin resonance, nuclear magnetic resonance, and optical absorption studies. It could be shown that an interaction exists between the metal ions and the hydrazine side chain in addition to the very weak interaction with the ring nitrogen. The results obtained indicate the formation of a charge transfer complex.

Eine neue Theorie über Photorezeption wird vorgeschlagen. Mittels EPR-Untersuchungen wird gezeigt, dass die in der Retina vorkommenden Elemente Schwefel und Eisen eine wichtige Rolle im Photorezeptionsprozess spielen. Für die Nervenerregung scheinen Ladungsleitungen und nicht intermolekulare Energieleitungen verantwortlich zu sein.

Extremely radiation hard sensors are needed in particle physics experiments to instrument the region near the beam pipe. Examples are beam halo and beam loss monitors at the Large Hadron Collider, FLASH or XFEL. Currently artificial diamond sensors are widely used. In this paper single crystal sapphire sensors are considered as a promising alternative. Industrially grown sapphire wafers are available in large sizes, are of low cost and, like diamond sensors, can be operated without cooling. Here we present results of an irradiation study done with sapphire sensors in a high intensity low energy electron beam. Then, a multichannel direction-sensitive sapphire detector stack is described. It comprises 8 sapphire plates of 1 cm2 size and 525 μ m thickness, metallized on both sides, and apposed to form a stack. Each second metal layer is supplied with a bias voltage, and the layers in between are connected to charge-sensitive preamplifiers. The performance of the detector was studied in a 5 GeV electron beam. The charge collection efficiency measured as a function of the bias voltage rises with the voltage, reaching about 10% at 095 V. The signal size obtained from electrons crossing the stack at this voltage is about 02200 e, where e is the unit charge.

A new pixel detector for the CMS experiment was built in order to cope with the instantaneous luminosities anticipated for the Phase~I Upgrade of the LHC. The new CMS pixel detector provides four-hit tracking with a reduced material budget as well as new cooling and powering schemes. A new front-end readout chip mitigates buffering and bandwidth limitations, and allows operation at low comparator thresholds. In this paper, comprehensive test beam studies are presented, which have been conducted to verify the design and to quantify the performance of the new detector assemblies in terms of tracking efficiency and spatial resolution. Under optimal conditions, the tracking efficiency is $99.95\pm0.05\,\%$, while the intrinsic spatial resolutions are $4.80\pm0.25\,\mu \mathrm{m}$ and $7.99\pm0.21\,\mu \mathrm{m}$ along the $100\,\mu \mathrm{m}$ and $150\,\mu \mathrm{m}$ pixel pitch, respectively. The findings are compared to a detailed Monte Carlo simulation of the pixel detector and good agreement is found.

The status of the Silicon Microvertex Detector (SMD) and its installation into the LEP-I.3experiment are presented, highiighting novel features and sophisticated techniques.Preliminary results based on 1993 data are given and compared with Monte Carlo predictions, to understand the detector performances and its tracking capabilities.

Annals of the New York Academy of SciencesVolume 498, Issue 1 p. 307-311 Ascorbic Acid and Cataracta W. LOHMANN, W. LOHMANN Institut für Biophysik Universität Giessen Giessen, Federal Republic of GermanySearch for more papers by this author W. LOHMANN, W. LOHMANN Institut für Biophysik Universität Giessen Giessen, Federal Republic of GermanySearch for more papers by this author First published: July 1987 https://doi.org/10.1111/j.1749-6632.1987.tb23769.xCitations: 8 a Parts of this work were supported by grants from the Bundesministerium für Forschung und Technologie and from the Fonds der Chemischen Industrie. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume498, Issue1Third Conference on Vitamin CJuly 1987Pages 307-311 RelatedInformation

The ion mixing of Ti-steel bilayers with N+, Ar+, Ti+, Kr+ and Xe+ ions was investigated by means of Rutherford backscattering spectroscopy (RBS). The mixing rates exhibit a linear scaling with the deposited damage energy fD. No correlation between the properties of the mixing ion and the mixing efficiency was found. The results are compared with the predictions of ballistic and thermal-spike models.

Illumination of unstained 9 microns cryosections of lung tissue with 365 nm results in visible fluorescence light with a maximum intensity at about 460 nm. These fluorescence tomographical studies can be used for detecting carcinoma of the lung. The fluorescence pattern obtained can be matched nicely with histological findings. Since it takes less than 5 min for getting the fluorescence images, the fluorescence tomographical technique might be used in addition to established methods for determining the histology of a biopsy sample.

Abstract Lanthanide induced shifts using Yb(fod) 3 and Pr(fod) 3 were used for the signal assignments of the 13 C spectra of the 1,4‐benzodiazepines diazepam, desmethyldiazepam, prazepam and flurazepam, and for characterizing their solution conformation with respect to the substituents at N‐1 and C‐5. The phenyl substituent at C‐5 is found to be nearly coplanar with the π‐bond between C‐5 and N‐4, and the substituents at N‐1 seem to be orientated towards the carbonyl group with dihedral angles of either 60° or 120° between the bonds N‐1 and C‐2 and C‐12 and C‐13. The metal ions seem to bind to O‐2 with metal‐oxygen distances between 0.19 and 0.26 nm and bond angles between 117° and 167°. Contact shifts induced by Pr(fod) 3 are slightly larger than obtained for Yb(fod) 3 , whereas the latter reagent causes a stronger broadening.

Abstract The interaction of the antibiotic tetracycline with a few metal ions, esp. Cu(II), in different so l­ vents has been investigated by means of IR, ESR, and UV /VIS spectroscopy. It could be shown that the site of complexation depends on the solvent used. In DMSO the interaction occurs mainly via the A ring. In water (pH = 5.7) and octanol, the A chromophore as well as the BCD entity of the molecule are involved in complexation. If the tetracycline concentration exceeds the Cu(II) concentration, a 2 : 1 (antibiotic : Cu(II)) complex seems to be formed, at least in DMSO.

The Beam Radiation Instrumentation and Luminosity Project of the CMS experiment consists of several beam monitoring systems and luminometers. The upgraded Fast Beam Conditions Monitor is based on 24 single crystal diamond sensors with a two-pad metallization and a custom designed readout. Signals for real time monitoring are transmitted to the counting room, where they are received and processed by new back-end electronics designed to measure count rates on LHC collision, beam induced background and activation products to be used to determine the luminosity and the machine induced background. The system architecture and the signal processing algorithms will be presented.

The CMS Beam Radiation Instrumentation and Luminosity (BRIL) project is composed of several systems providing the experiment protection from adverse beam conditions while also measuring the online luminosity and beam background. Although the readout bandwidth of the Fast Beam Conditions Monitoring system (BCM1F—one of the faster monitoring systems of the CMS BRIL), was sufficient for the initial LHC conditions, the foreseen enhancement of the beams parameters after the LHC Long Shutdown-1 (LS1) imposed the upgrade of the system. This paper presents the new BCM1F, which is designed to provide real-time fast diagnosis of beam conditions and instantaneous luminosity with readout able to resolve the 25 ns bunch structure.

The endogenous fluorescence of human choroid, sclera, and retinal pigment epithelium (RPE) in normal tissue and tissue with uveal melanoma was studied in vitro by a non-invasive and non-destructive fluorescence technique which had previously been applied for the diagnostic evaluation of pigmented lesions of the skin. The fluorescence of the normal choroid is rather dark, the normal sclera exhibits blue fluorescence and the RPE bright yellow fluorescence due to deposits of lipofuscin. In choroidal melanoma, the lipofuscin granulae at the level of the retinal pigment epithelium are cleaved off above the tumour and broken up into small remnants. The fluorescence intensity emitted from the tumour is rather low which agrees with previous findings on skin melanomas. The results may become interesting for diagnostic evaluation of uveal melanomas, uveal naevi, and pigmented conjunctival tumours by endogenous fluorescence.

The formation of hydrogen bonds between the minor tranquilizers diazepam and nitrazepam and a few nucleobases was studied in deuterochloroform solution by means of proton magnetic resonance spectroscopy. The thermodynamic and spectroscopic data of the associations were evaluated on the basis of a dimer model, using the concentration dependent shifts of the protons involved in hydrogen bonds. The interactions of nitrazepam (deltaH0=-10 to -21 kJ/mol; deltaG025 -0.2 to -7.4 kJ/mol) were found to be stronger than those of diazepam (deltaH0=-10 to -13 kJ/mol; deltaG025=6.0 to 6.4 kJ/mol). The various binding sites of the benzodiazepines for hydrogen bonds are discussed.

The electromagnetic and weak dipole moments of the τ-lepton have been measured by experiments at e+e− colliders. Data samples of e+e−→τ+τ−, e+e−→τ+τ−γ and e+e−→e+e−τ+τ− events collected at centre-of-mass energies between 10 and 200 GeV are used. No deviation from the Standard Model is found. Limits on the moments are summarised from the most recent results.

Amorphous metals (AM) are promising materials for use in high dose irradiation environments due to their often higher irradiation resistance compared to crystalline metals, at least regarding dpa-type damage. A high thermal stability and a sufficient mechanical stiffness is required additionally for the envisaged application as a stationary proton beam window of the German spallation neutron source. Potentially suitable AM's are identified by theoretical considerations. The possibility of using known, but specially prepared AM's is discussed in detail. Concerning the gas-embrittlement, for the first time a He-bulk implantation has been performed on the AM Ni/sub 78/Si/sub 8/B/sub 14/ at room temperature and 300/sup 0/C up to a He-concentration of 1.000 appM. A clear He-influence is not observed on the ductility losses, which can be attributed to a temper embrittlement. TEM investigations reveal no discernable He-bubbles both for as-implanted and subsequently annealed specimens up to the crystallization temperature.