Raman Khurana

This document is the final report of the ATLAS-CMS Dark Matter Forum, a forum organized by the ATLAS and CMS collaborations with the participation of experts on theories of Dark Matter, to select a minimal basis set of dark matter simplified models that should support the design of the early LHC Run-2 searches. A prioritized, compact set of benchmark models is proposed, accompanied by studies of the parameter space of these models and a repository of generator implementations. This report also addresses how to apply the Effective Field Theory formalism for collider searches and present the results of such interpretations.

We report the construction of a non-toxic nanoassembly of bovine serum albumin (BSA) protein and the cucurbit[7]uril macrocycle as well as its stimuli-responsive breakage with adamantylamine or pH, which restores the protein structure and recognition properties. The assembly showed efficient loading and controlled release of a standard drug, doxorubicin (DOX), and the same was validated in live cells. The cell viability studies documented that the DOX-loaded assembly mask the cytotoxicity of DOX and the toxicity can be revived at the target on demand, triggering its therapeutic activation. This is found to be more effective in the cancer cells. In addition, such host-assisted protein assemblies are also highly promising for stabilizing/protecting the native protein structure, a viable approach to prevent/inhibit protein misfolding and aggregation.

Porphyrins, especially the 5,10,15,20-tetrakis(4-N-methylpyridyl) porphyrin (TMPyP), are well-accepted as photosensitizers due to strong absorption from visible to near-infrared region, good singlet oxygen quantum yields as well as chemical versatility, all of which can be further modulated through planned supramolecular strategies. In this study, we report the construction of supramolecular nanorods of TMPyP dye/drug with captisol [sulfobutylether-β-cyclodextrin (SBE7βCD)] macrocycle through host-guest interaction. The availability of four cationic N-methylpyridyl groups favors multiple binding interaction with the captisol host, building an extended supramolecular assembly of captisol and TMPyP. In addition to the spectroscopic characterizations for the assembly formation, the same has been pictured in SEM and FM images as nanorods of ~10 μm in length or more. Complexation of TMPyP has brought out beneficial features over the uncomplexed TMPyP dye; enhanced singlet oxygen yield, improved photostability, and better photosensitizing effect, all supportive of efficient photodynamic therapy activity. The Captisol:TMPyP complex displayed enhanced antibacterial activity toward E. coli under white light irradiation as compared to TMPyP alone. Cell viability studies performed in lung carcinoma A549 cells with light irradiation documented increased cytotoxicity of the complex toward the cancer cells whereas reduced dark toxicity is observed toward normal CHO cells. All these synergistic effects of supramolecular nanorods of Captisol-TMPyP complex make the system an effective photosensitizer and a superior antibacterial and antitumor agent.

Work leading to the structue elucidation of butolic and jalaric acids has been described. A new “lac acid” laksholic acid has been isolated and its structure established. It is suggested that the primary lac acid is jalaric acid and that shellolic and laksholic acids (and their epimers) arise from jalaric acid by a Cannizzaro reaction under conditions of alkaline hydrolysis.

Ammonia borane (AB) is considered a potential “on-board” hydrogen storage material. However, its implementation as a hydrogen reservoir in fuel cells is lacking due to the extremely slow release of hydrogen at room-temperature hydrolysis. In this study, a metal-free supramolecular strategy is demonstrated at room temperature to increase the hydrolysis rate and yield of hydrogen along with significant reduction in ammonia release by using cucurbit[5/8]uril (CB5/CB8) nanocavitands as catalysts. The complex of AB with CB stabilizes the ammonium ion at the host portals, which reduces ammonia release and enhances hydrogen yield. The complexation brings down the activation energy of hydrolysis from 103.8 to ∼27.5 kJ mol–1 (for CB5), a value close to the Pt/Pd nanoparticle-based catalysts reported so far. The high catalytic performance and reusability of CB catalysts at very low concentration make AB a promising supramolecular alternative for a sustainable “on-board” energy source.

A modified procedure for the isolation of “hard resin” from seed-lac is described. An integrated procedure for the isolation of various lac acids from the “hard resin” hydrolysate has been developed. Paper and thin-layer chromatography characteristics of various lac acids and their methyl esters are reported. Quantitative estimation of aleuritic acid and aldehydic arids in “hard” and “soft resins” of various origins has been carried out.

Anomalous aggregation of proteins into amyloid fibrils leads to various amyloidosis diseases including neurodegenerative disorders. Inhibition of fibrillation process and rupture of mature amyloid fibril/plaques using small organic molecules are the promising remedial strategies to combat neurodegenerative diseases. In this study, we present sulfobutylether-β-cyclodextrin (SBE7β-CD), a water-soluble macrocycle, as an efficient additive to inhibit the fibril formation and also for the breakage of mature fibrils into nontoxic small particles. The steady-state and time-resolved fluorescence, circular dichroism measurements and fluorescence microscopic images collectively confirm the inhibition and rupture of the amyloid fibrils in the presence of SBE7β-CD. In one hand, the macrocyclic encapsulation of certain amino acid residues on the protein stabilizes the native form of insulin and lysozyme and prevents their transformation into the β-sheet conformers, resulting in the inhibition of fibrillation. On the other hand, the degeneration of the fibril strands became feasible due to the overall positive charge of the fibril surface and the negative portals of the SBE7β-CD host. Positively, the nontoxic SBE7β-CD additive mitigates the toxicity of the system and is highly promising as therapeutics for amyloidosis.

The noncovalent host-guest interactions of the cationic (AcH+) and neutral (Ac) forms of an acridine dye with macrocyclic hosts such as cucurbit[7]uril (CB7) and cucurbit[8]uril (CB8) have been investigated to evaluate the effect of cavity size on the photophysical properties and the protolytic equilibrium of the acridine dye. The cationic form undergoes significant complexation with CB7 (Keq = 106 M-1), causing a sharp decrease in the fluorescence intensity, whereas the neutral Ac form of the dye undergoes weak complexation with CB7 (Keq = 103 M-1) and the binding constant is lowered by three orders of magnitude compared to that of the CB7-AcH+ system. The Job plot revealed that both forms form a 1 : 1 complex with CB7. On the other hand, the AcH+ form shows strong emission quenching on interaction with CB8 and the formation of the 1 : 2 CB8 : AcH+ complex has been confirmed from the Job plot. The strong affinity of CB7 and CB8 to the protonated form resulted in a large upward pKa shift (ΔpKa ∼ 3.4 units for CB7 and ∼1.3 units for CB8) in the dye. Taking advantage of the above modulations in the fluorescence and pKa values, adamantylamine-induced fluorescence regeneration, controlled pKa tuning and dye relocation from the CB7 cavity to cell lines have been established for the first time, which find potential applications in fluorescence off-on sensing and drug delivery.

The High Luminosity phase of the Large Hadron Collider will deliver 10 times more integrated luminosity than the existing collider, posing significant challenges for radiation tolerance and event pileup on detectors, especially for forward calorimetry. As part of its upgrade program, the Compact Muon Solenoid collaboration is designing a high-granularity calorimeter (HGCAL) to replace the existing endcap calorimeters. It will feature unprecedented transverse and longitudinal readout and triggering segmentation for both electromagnetic and hadronic sections. The electromagnetic section and a large fraction of the hadronic section will be based on hexagonal silicon sensors of 0.5–1 cm2 cell size, with the remainder of the hadronic section being based on highly-segmented scintillators with silicon photomultiplier readout. The intrinsic high-precision timing capabilities of the silicon sensors will add an extra dimension to event reconstruction, especially in terms of pileup rejection. First hexagonal silicon modules, using the existing Skiroc2 front-end ASIC developed for CALICE, have been tested in beams at Fermilab and CERN in 2016. We present results from these tests, in terms of system stability, calibration with minimum-ionizing particles and resolution (energy, position and timing) for electrons, and the comparisons of these quantities with GEANT4-based simulation.

The amelioration of antibacterial efficacy along with the reduced minimum inhibitory concentration (MIC) of sanguinarine (SGR) drug have been demonstrated through the uptake of SGR by p-sulfonatocalix[6]arene functionalized silver nanoparticles. The large upward pKa shift and enhanced stability of SGR resulting from the favorable supra-nanomolecular strategy are deciphered into an improved antibacterial drug against different pathogenic micro-organisms including multi drug resistant bacteria.

Abstract Modulation and control of stimuli responsive features of molecular assemblies in organized assemblies/cavitand macrocycles have received immense attention in many areas. In this study, we have established the formation of a discrete molecular assembly of thiazole orange (TO) dyes at the portals of the sulfobutylether β‐cyclodextrin (SBE 7 βCD) macrocycle leading to the evolution of a strong and distinct emission band from aggregated TO. The supramolecular assembly promoted portal aggregation of TO in its 1 : 4 (SBE 7 βCD : TO) composition, characterized by absorption, fluorescence, circular dichroism, ITC and 1 H NMR measurements, was probed to be selectively responsive to tyramine among other biogenic amines/neurotransmitters. For the first time, the different extent of emission quenching of SBE 7 βCD : TO assembly in the presence of biogenic amines/neurotransmitters is translated to achieve a selective on‐off fluorescence sensor for the detection of tyramine against other neurotransmitters with a limit‐of‐detection (LOD) as low as ∼575 nM (79 ppb). The emission features of the assembly with changes in temperature is found to be highly reproducible even after several temperature cycles and is promising to design an optical supramolecular thermometer in the ambient temperature range.

We present measurements of the reduction of light output by plastic scintillators irradiated in the CMS detector during the 8 TeV run of the Large Hadron Collider and show that they indicate a strong dose rate effect. The damage for a given dose is larger for lower dose rate exposures. The results agree with previous measurements of dose rate effects, but are stronger due to the very low dose rates probed. We show that the scaling with dose rate is consistent with that expected from diffusion effects.

This book chapter delves into the effect of courage as a moderator on the indirect association between self-kindnessSelf-kindness and isolationIsolation through humanity using a moderated mediation modelModerated Mediation Model. One hundred and fifty Indian manufacturing and service sector executives have been surveyed using a cross-sectional questionnaire-based approach. Hayes PROCESSPROCESS macro is used to test the significance of the associations hypothesized along with bootstrapped results. The findings reflect the adverse indirect influence of self-kindnessSelf-kindness on isolation through humanityHumanity, with the negative impact being lessened at lower levels of courageCourage. Furthermore, it has also been observed that humanity and isolationIsolation are negatively associated. This study suggests that employees' isolation decreases through their self-kindness and humanityHumanity when they have a high level of courage. An assessment of the implications and future prospects in relation to the findings has been made.

Supramolecular p<italic>K</italic>_a shift and fluorescence quenching in a neutral red dye in the presence of <italic>p</italic>-sulfonatocalix[4/6]arenes have been demonstrated, which are relevant for the off–on switch, ion sensitive electrodes and drug delivery vehicles.

Abstract Although aqueous dye lasers are much sought after, they have been of no practical use, as laser dyes show a strong tendency for aggregation in water, thus diminishing their optical output. Contributing towards this shortcoming, we studied the noncovalent interactions of two prominent laser dyes, namely, rhodamine 6G and rhodamine B, with a water soluble macrocyclic host, sulfobutylether‐β‐cyclodextrin (SBE 7 βCD). Spectral changes in the absorption and fluorescence behavior of dyes in presence of the SBE 7 βCD host indicated adequate complex formation between dye and host ( K ∼10 4 M −1 ). A combination of various photophysical parameters evaluated from measurements such as Job plot, changes in the fluorescence lifetime/anisotropy values, and favorable thermodynamic parameters from isothermal titration calorimetric measurements adjudicated a 1 : 1 stoichiometric complex formation between dye and SBE 7 βCD host. Consequently, SBE 7 βCD prevents dye aggregation/adsorption and present rhodamine dyes in their monomeric forms with enhanced fluorescence yield and brightness. These vital parameters were utilized to optimize and demonstrate cost‐effective supramolecular broad‐band and narrow‐band aqueous dye laser systems with improved lasing efficiencies (∼25 % higher for the SBE 7 βCD : RhB system and ∼10 % higher for SBE 7 βCD : Rh6G system), better beam profile, and enhanced durability compared to the respective dyes in optically matched ethanol solutions.

Abstract Deaggregated perylenediimide (PDI) derivatives exhibit exceptionally high quantum yields, photostability and appropriate molecular features for organic electronics. This work demonstrates a metal–dye–metal framework with a large and stable negative differential resistance (NDR) at ambient conditions, built using a supramolecular strategy. The deaggregation achieved through the encapsulation of the bay‐substituted phenyl groups of aggregated ( l/d )‐Phe‐PDI dyes by the β‐CD macrocyclic host is validated through detailed spectroscopic and imaging techniques. The host–guest interaction resulted in a dramatic enhancement in the emission yield from 0.28 to 0.90. In the thin film deposits, the β‐CD/( l/d )‐Phe‐PDI complex displayed well‐connected sheet‐like morphology, whereas the uncomplexed ( l/d )‐Phe‐PDI dye remained as scattered lumps. The large and reversible I–V characteristics displaying strong NDR behavior is attributed to the oxidation/reduction processes involving the rigid π‐rich PDI core and is stable at least for about six months at ambient conditions, a promising system for organic electronics applications.

Two red-emitting water-soluble fluorophores bearing a coumarin scaffold were synthesized and their interactions with cucurbit[7]uril [CB7] were investigated. A significant red-shift in the absorption spectra showed the interaction of coumarin dyes with the carbonyl portals of CB[7]. The formation of supramolecular complex is substantiated by the chemical shift changes in 1H-NMR and the thermodynamic parameters were evaluated by isothermal calorimetric titration (ITC). Upon encapsulation with the non-fluorescent CB host, significant enhancement of fluorescence quantum efficiency is observed. The large modulation of the emission properties of fluorophores in the presence of CB[7] indicates the formation of supramolecular complex. The advantageous enhanced quantum efficiency of the CB-dye complexes, is utilized to image live cells revealing localization in cellular membranes with greater photostability. These results based on inclusion complexes of the coumarin fluorophores with a non-toxic host CB[7] could lead to the design of efficient biological probes.

pH-responsive emission behavior of supramolecular complexes between pyridylbutadiene with CB7 and formation of molecular assemblies is described.

In the last two decades, perchlorate salts have been identified as environmental pollutants and recognized as potential substances affecting human health. We describe self-assembled monolayers (SAMs) of novel semiaza-bambus[6]urils (semiaza-BUs) equipped with thioethers or disulfide (dithiolane) functionalities as surface-anchoring groups on gold electrodes. Cyclic voltammetry (CV) with Fe(CN)63-/4- as a redox probe, together with X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and ellipsometry, were employed to characterize the interactions at the interface between the anchoring groups and the metal substrate. Data showed that the anion receptors' packing on the gold strongly depends on the anchoring group. As a result, SAMs of BUs with lipoic amide side chains show a concentration-dependent layer thickness. The BU SAMs are extremely stable on repeated electrochemical potential scans and can selectively recognize perchlorate anions. Our electrochemical impedance spectroscopy (EIS) studies indicated that semiaza-BU equipped with the lipoic amide side chains binds perchlorate (2-100 mM) preferentially over other anions such as F- , Cl- , I- , AcO- , H2 PO4- , HPO42- , SO42- , NO2- , NO3- , or CO32- . The resistance performance is 10 to 100 times more efficient than SAMs containing all other tested anions.

Perylenediimide (PDI) chromophores with redox-active groups have facilitated the construction of several novel functional materials. For the first time, unusual spectroscopic changes and differential binding behavior of a tetracationic ethyl viologen tethered PDI derivative, PDEV, with calf-thymus DNA (ct-DNA) is reported here and is ascertained as due to the DNA compaction. From an initial aggregation on the DNA backbone, resulting in quenching in the emission intensity (turn off), with increase in ct-DNA concentration, a novel and strong fluorescence band (turn on) emerged in the blue region. Distinct absorption spectral changes having sharp features in vibronic patterns, increased fluorescence lifetime (from 0.33 to 4.5 ns), anisotropy values are also displayed on titration with ct-DNA corroborating the changes in microenvironment of PDEV in commensurate with structural transition from coil state to compact state. The structural changes in the DNA are also established from the circular dichroism spectra, viscosity measurements, and DNA melting data. The compaction is also directly visualized in the atomic force microscopy, scanning electron microscopy, and fluorescence microscopy images. Such compact DNA morphologies with redox-responsive donor–acceptor moieties are potential to create desired nanostructures with stimuli-responsive functionalities such as on–off switch, biosensor, drug delivery, and other optoelectronic devices.

Abstract Host‐guest interaction of macrocyclic receptor, cucurbit[8]uril (CB8), with neutral bichromophoric coumarin 30 (C30) dye has been investigated using various spectroscopic tools. Absorption and fluorescence emission results along with 1 H NMR data have demonstrated the existence of host‐guest complex of C30 dye with CB8 host in a 1:2 and 3:2 (CB8:C30) stoichiometries. Comparative studies with the photophysical aspects of the protonated C30 dye (at pH 3) confirmed that interaction of neutral C30 dye (at pH 7) with CB8 has led to the host assisted protonation of C30 in the CB8:C30 complex, registering an upward supramolecular p K a shift of about 3 units. The 3:2 stoichiometric complex exhibits strong excimer emission and is dictated by the structural features of C30. Due to this complexation not only we accomplish modulation in the photophysics of the dye, but also it enhances the aqueous solubility of C30, especially at pH 7. Taking advantage of CB8 assisted tunable p K a shift, currently we are pursuing the prospects of using photostable coumarin dyes for cellular imaging studies as well as their applicability as aqueous dye laser systems.

Supramolecularly assembled building blocks, especially those based on π stacked organic or inorganic redox active materials have found encouraging applications in recent years due to their electron-accepting nature and easy structural manipulations. In this regard, by employing various spectroscopic, thermodynamic and imaging measurements we establish the generation, stabilization and in situ reaction of a novel supramolecularly supported emissive radical anions through host–guest interaction of N, Ń-bis[2-(2-aminoethyl)benzimidazolyl] naphthalene diimide (BzNDI) with Cucubit[n]uril (CB7 and CB8) macrocycles in aqueous medium. While the CB7 and CB8 hosts revealed distinct interactions with the BzNDI, the CB8 complexation displayed a novel excimer emission band in the 523 nm region, which originated from dimeric inclusion of BzNDI dyes in to the larger CB8 cavity. These CB7/CB8 stabilized BzNDI complexes undergo photoinduced electron transfer process to generate respective radical anions. These transient radical anions held in the cucurbituril nanocavities displayed characteristic emission spectra in the visible region and longer lived (τav ~ 6.5 ns) radical excited states and the radical anions are found to be reversible to their parent complex under ambient condition in ~1–2 h. This dynamic stability window of the radical anions has been used for the in situ reduction of Au3+ to generate stable AuNPs. It is noteworthy that this chemistry was not observed with BzNDI in the absence of CB7/CB8 host interaction. We foresee that the demonstrated stimuli responsive supramolecular approach has the potential for the controlled assembly of smart materials, radical polymerization, molecular electronics and other gated radical induced reactions.

semiaza-Bambus[6]urils efficiently transport anions across lipid membranes. A systematic modification of their lipophilic side chains to include various alkyl groups and thioethers reveals that the most efficient chloride transporters are those that agree with Lipinski's rule-of-lipophilicity, exhibiting clog Po/w values close to 5. Furthermore, vesicle anion-transport assays show that the new anion-transporters are independent of the cation identity but exhibit high anion selectivity, NO3- > Br- > Cl- > SO42-, in agreement with the Hofmeister series. These findings will allow for the design of highly specific anion transporters for biomedical applications, particularly for managing anion channelopathies.

Abstract Construction and characterization of stimuli‐responsive supra‐biomolecular nanoassembly between cucurbit[7]uril (CB7) and bovine serum albumin (BSA), uptake and release of doxorubicin (DOX) in live cells, the enhanced sensitivity of brilliant green (BG) and the metal ion‐induced relocation of neutral red (NR) dye to BSA have been discussed in this review. The fluorescence intensity of DOX is largely quenched in the presence of nanoassembly which recovers with adamantylamine or by changing the pH of the solution, indicating the significant uptake and release of DOX. Whereas, the interaction of BG with CB7‐BSA assembly leads to a huge fluorescence enhancement ∼350‐fold through ternary complex formation. In another study, the supramolecular p K a tuning of nanoassembly encapsulated NR dye with metal ion and the consequent relocation of NR from CB7 cavity to the hydrophobic pocket of BSA have been demonstrated. All these studies show promising applications in drug delivery and on‐off sensor.

A readout box prototype for the CMS Hadron Forward calorimeter upgrade was built and tested in the CERN H2 beamline. The prototype was designed to enable simultaneous tests of different readout options for the four anode upgrade PMTs, new front-end electronics design and new cabling. The response of the PMTs with different readout options was uniform and the background response was minimal. Multi-channel readout options further enhanced the background elimination. Passing all the electronic, mechanical and physics tests, the readout box proved to be capable of providing the forward hadron calorimeter operational requirements in the upgrade era.

Construction of smart materials based on supramolecular interactions has received considerable research interest owing to their potential applications in energy storage, photonic devices, drug delivery vehicles, sensors as well as therapeutics. In this context, research literature has seen tremendous contributions on the supramolecular assemblies of small guest molecules with various macrocyclic receptors because they provide a unique way to control tailor-made nanoarchitectures in creating predesigned functional materials for targeted applications. This chapter covers some of the recent works, including ours, on the spectacular molecular properties of cucurbituril-based supramolecular functional assemblies of a few organic dyes and polyoxometalates having technological and biological importance, especially in the domain of aqueous dye laser, light-emitting devices, photofunctional devices, energy storage devices, molecular architectures, supramolecular catalysts, radiotracer separation, antibacterial agents and drug delivery vehicles.

The study emphasizes the role of an individual's mindfulness and temperance in making employees fit their organizations by comparing the direct effect of mindfulness and its indirect effect through temperance on the employees' person–organization fit (P-O fit). Data were collected from 185 Indian employees working at managerial positions in manufacturing and service industries through an online questionnaire in a cross-sectional research design. Structure equation modelling (SEM) was used to test the associations, and it was observed that mindfulness among employees is positively related to their P-O fit. Similarly, employees' temperance is also positively associated with their P-O fit. Furthermore, it is observed that temperance acts as a partial mediator between mindfulness and P-O fit. Mindful employees would be more aware of their surroundings, making them aware of the values that the workplace demands. The same awareness would compel the employees to have temperance (self-control) to keep their values in line with organizational values. The study contributes to the virtue theory and the value congruence theory in the organizational context. This study recommends that the management promotes mindfulness and temperance among the employees through various interventions and new technological aids to promote the P-O fit of the employees. To the best of our knowledge, this original work has novelty to investigate the relationship of mindfulness with P-O fit, taking into account the role of temperance of the employee.

The detection of perchlorate is necessary for monitoring environmental pollution. In their Research Article (DOI: 10.1002/chem.202302968), E. Keinan, J. Huskens, O. Reany and co-workers show that self-assembled monolayers of semiaza-bambus[6]urils show excellent sensitivity and selectivity in the electrochemical impedimetric detection of the perchlorate anion in comparison to other anions.

ABSTRACT We describe here a rare entity of Holoprosencephaly. The embryogenesis and the diagnostic aspects of this condition are highlighted.