Ratio Of Conformers Research Articles

N-point functions in conformal quantum mechanics: a momentum space odyssey

In this paper, we study the implications of conformal invariance in momentum space for correlation functions in quantum mechanics. We find that three point functions of arbitrary operators can be written in terms of the 2F1 hypergeometric function. We then show that generic four-point functions can be expressed in terms of Appell’s generalized hypergeometric function F2 with one undetermined parameter that plays the role of the conformal cross ratio in momentum space. We also construct momentum space conformal partial waves, which we compare with the Appell F2 representation. We test our expressions against free theory and DFF model correlators, finding an exact agreement. We then analyze five, six, and all higher point functions. We find, quite remarkably, that n-point functions can be expressed in terms of the Lauricella generalized hypergeometric function, EA, with n − 3 undetermined parameters, which is in one-to-one correspondence with the number of conformal cross ratios. This analysis provides the first instance of a closed form for generic momentum space conformal correlators in contrast to the situation in higher dimensions. Further, we show that the existence of multiple solutions to the momentum space Ward identities can be attributed to the Fourier transforms of the various possible time orderings. Finally, we extend our analysis to theories with N\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{N} $$\\end{document} = 1, 2 supersymmetry, where we find that the constraints due to the superconformal ward identities are identical to identities involving hypergeometric functions.

Role of Density and Conformational Composition in the Surface-to-Bulk Molecular Dosing of Photosensitive Surfactant Monolayers.

Poorly water-soluble photosensitive monolayers might enable very precise control of the rate and number of desorbing molecules by controlling both the monolayer density and conformational composition. In this perspective, we systematically characterized the interfacial behavior of Langmuir monolayers consisting of a poorly water-soluble azobenzene-containing surfactant as a function of its trans/cis ratio. Precise control of the conformational ratio was achieved by controlling the UV irradiation time, allowing researchers to investigate compositions spanning from 100% trans to 90% cis. Our results demonstrate that in 100% trans monolayers, molecules do not desorb with compression until a threshold area is reached. Instead, the number of molecules desorbing in mixed trans-cis monolayers can be modulated by controlling both the composition and the compression rate. Additionally, the desorption rate at constant density is also strongly composition-dependent, and it accounts for two different regimes with two different characteristic times. We will show that trans molecules mostly desorb according to the slow regime while cis molecules conform to the fast one, but the two conformers mutually influence each other.

Influence of Solvent Polarity on the Conformer Ratio of Bicalutamide in Saturated Solutions: Insights from NOESY NMR Analysis and Quantum-Chemical Calculations.

The study presents a thorough and detailed analysis of bicalutamide's structural and conformational properties. Quantum chemical calculations were employed to explore the conformational properties of the molecule, identifying significant energy differences between conformers. Analysis revealed that hydrogen bonds stabilise the conformers, with notable variations in torsion angles. Conformers were classified into 'closed' and 'open' types based on the relative orientation of the cyclic fragments. NOE spectroscopy in different solvents (CDCl3 and DMSO-d6) was used to study the conformational preferences of the molecule. NOESY experiments provided the predominance of 'closed' conformers in non-polar solvents and a significant presence of 'open' conformers in polar solvents. The proportions of open conformers were 22.7 ± 3.7% in CDCl3 and 59.8 ± 6.2% in DMSO-d6, while closed conformers accounted for 77.3 ± 3.7% and 40.2 ± 6.2%, respectively. This comprehensive study underscores the solvent environment's impact on its structural behaviour. The findings significantly contribute to a deeper understanding of conformational dynamics, stimulating further exploration in drug development.

Three-point energy correlators in hadronic Higgs boson decays

We present the analytic calculation of the leading-order three-point energy correlator (EEEC) in hadronic Higgs decays, including both the gluon-initiated channel H→gg+X and quark-initiated channel H→qq¯+X. The phase-space integration is evaluated directly using Mandelstam variables sij=(pi+pj)2, and the appearing square roots can be rationalized by either conformal ratios or celestial coordinate variables. Throughout the calculation, we observe the same transcendental function space as in N=4 super–Yang-Mills theory and e+e−→hadrons. Different infrared limits are also explored using the full analytic result, offering the fixed-order data for EEEC factorization and resummation. Given its nontrivial shape dependence, the EEEC presents an excellent opportunity to explore the dynamics of gluon jets originating from the H→gg decay channel at future lepton colliders. Published by the American Physical Society 2024

The human dermal white adipose tissue (dWAT) morphology: A multimodal imaging approach

BackgroundDermal white adipose tissue (dWAT) in humans can be characterized as a relaxed dermal skin compartment consisting of functionally interlinked adipocytes. dWAT is typically discerned both in terms of morphology and function from subcutaneous white adipose tissue (sWAT). In particular in human thigh, the dWAT appears as thin extensions from the adipose panniculus to the dermis, and it is primarily associated with pilosebaceous units, hair follicles, sebaceous glands, and erector pili muscles. In this work, human fat tissue samples obtained post-mortem from the gluteo-femoral region were analyzed focusing on the thin extensions of dWAT named dermal cones. This anatomical region was chosen to deepen the dWAT morphological features of this site which is interesting both for clinical applications and genetical studies. The purpose of this exploratory methodological study was to gain deeper insights into the morphological features of human dWAT through a multimodal imaging approach. MethodsOptical microscopy, Magnetic Resonance Imaging (MRI) and Scanning Electron Microscopy (SEM), have been employed in this study. The cones’ length and their distances were measured on the acquired images for optical microscopy and SEM. The cone’s apparent regular distribution in MRI images was evaluated using a mathematical criterion, the conformity ratio, which is the ratio of the mean nearest-neighbor distance to its standard deviation. ResultsThe imaging techniques revealed white adipocytes forming a layer, referred to as sWAT, with cones measuring nearly 2 mm in size measured on SEM and Optical images (2.1 ± 0.4 mm), with the lower part embedded in the sWAT and the upper part extending into the dermis. The distance between the cones results about 1 mm measured on MRI images and they show an overall semiregular distribution. ConclusionsMRI images demonstrated an orderly arrangement of cones, and their 3D reconstruction allowed to elucidate the dermal cones’ disposition in the tissue sample and a more general comprehensive visualization of the entire fat structure within the dermis.

Exploring the physicochemical properties of the integration of Tristearoyl uridine in Langmuir monolayers: An approach to cell membrane modeling for prodrugs

Understanding the mechanisms by which drugs interact with cell membranes is crucial for unraveling the underlying biochemical and biophysical processes that occur on the surface of these membranes. Our research focused on studying the interaction between an ester-type derivative of tristearoyl uridine and model cell membranes composed of lipid monolayers at the air-water interface. For that, we selected a specific lipid to simulate nontumorigenic cell membranes, namely 1,2-dihexadecanoyl-sn-glycero-3-phospho-l-serine. We noted significant changes in the surface pressure-area isotherms, with a noticeable shift towards larger areas, which was lower than expected for ideal mixtures, indicating monolayer condensation. Furthermore, the viscoelastic properties of the interfacial film demonstrated an increase in both the elastic and viscous parameters for the mixed film. We also observed structural alterations using vibrational spectroscopy, which revealed an increase in the all-trans to gauche conformers ratio. This confirmed the stiffening effect of the prodrug on the lipid monolayer. In summary, this study indicates that this lipophilic prodrug significantly impacts the lipid monolayer's thermodynamic, rheological, electrical, and molecular characteristics. This information is crucial for understanding how the drug interacts with specific sites on the cellular membrane. It also has implications for drug delivery, as the drug's passage into the cytosol may involve traversing the lipid bilayer.

Infrared spectroscopy for evaluating the effect of electron beam sterilization on polyethylene terephthalate medical tubes

The paper studies the effect of electron beam sterilization on the polyethylene terephthalate parts of blood sampling systems. The structural state and crystallinity degree of polyethylene terephthalate are estimated from the analysis of infrared spectra. Relative intensities are calculated by the reference band (overall intensity level) at 1410 cm−1. The Gaussian intensities of the absorption bands for trans and gauche conformations with respect to reference band at 1505 cm–1 are calculated. The spectral coefficients D973/D795, D848/D795, D1042/D795, D895/D795, D1098/D1370, and D1255/D1370 are determined. The dose of up to 25 kGy has no significant effect on either the ratio of integral intensities or the ratio of trans and gauche conformations.

Integrated engineering at distal site and active center regulates stereoselectivity and activity of carbonyl reductase towards N-Boc-pyrrolidone

Green and efficient biosynthesis of two enantiomeric products of N-Boc-pyrrolidinol (NPBL) as key pharmaceutical blocks for treatment of cancer and HIV has received much attention. The precursor, N-Boc-pyrrolidone (NPBO), is considered as a difficult-to-reduce ketone by carbonyl reductases, because it has a bulky Boc group and sterically similar substitutions on either side of the carbonyl group resulting in low stereoselectivity and conversion. Moreover, activity enhancement concomitant with reversal of stereoselectivity is challenging. Carbonyl reductase (CpCR) from Candida parapsilosis shows 90 %ee for (S)-NBPL, but low catalytic efficiency. In this study, we considered both activity and selectivity, and proposed an integrated engineering strategy. The distal site was introduced from an activity perspective and the active pocket sites were introduced by virtual saturation mutagenesis from a stereoselectivity perspective. Mutants L34A/W116A (95 %ee (S)) and L34A/W116T/F285C/W286S (94 %ee (R)) were obtained with 26.8-fold and 2.9-fold higher catalytic efficiencies, respectively. Molecular dynamics simulations revealed the mechanism of stereoselective flip-flop and activity enhancement; mutation altered the substrate-binding mode and changed the shape and size of the cavities, thus contributing to the change in the ratio of active conformations in the pre-reactive state. This study, which differs from the traditional method of exchanging large and small pockets, provides a viable approach for the rational design of carbonyl reductases with high stereoselectivity for target substrates.

Probing solution conformations of l-DOPA: Integration of experiment and simulation via vibrational optical activity

l-DOPA plays a critical role as a precursor to dopamine and is a standard treatment for Parkinson's disease. Recent research has highlighted the potential therapeutic advantages of deuterated l-DOPA analogs having a longer biological half-life. For their spectroscopic characterization, the in-detail characterization of l-DOPA itself is necessary. This article presents a thorough examination of the vibrational spectra of l-DOPA, with a particular emphasis on chirally sensitive VOA techniques. We successfully obtained high-quality Raman and ROA spectra of l-DOPA in its cationic form, under low pH conditions, and at a high concentration of 100 mg/ml. These spectra cover a broad spectral range, allowing for precise comparisons with theoretical simulations. We also obtained IR and VCD spectra, but they faced limitations due to the narrow accessible spectral region. Exploration of l-DOPA's conformational landscape revealed its intrinsic flexibility, with multiple coexisting conformations. To characterize these conformations, we employed two methods: one involved potential energy surface scans with implicit solvation, and the other utilized molecular dynamics simulations with explicit solvation. Comparing ROA spectra from different conformer groups and applying spectral decomposition proved crucial in determining the correct conformer ratios. The use of explicit solvation significantly improved the quality of the final simulated spectral profiles. The accurate determination of conformer ratios, rather than solely relying on the number of averaged spectra, played a crucial role in simulation accuracy. In conclusion, our study offers valuable insights into the structure and conformational behavior of l-DOPA and represents a valuable resource for subsequent spectroscopic studies of its deuterated analogs.

Study on Load Distribution and Fatigue Elastic Life of Ball Screw under Ultimate Conditions

When subjected to extreme loads and ultra-low cycling conditions, the primary mode of failure in a ball screw is that excessive plastic contact deformation of the raceway surface exceeds acceptable limits. Consequently, traditional fatigue life theories based on pitting fatigue are not applicable in this context. This study evaluated the load distribution within the ball screw, considering factors such as the nut position and screw length. The plastic deformation of the raceway surfaces is analyzed using Thornton’s elastoplastic theory. Furthermore, this paper integrates the concepts of plastic deformation and fatigue elastic life to investigate the fatigue elastic life of ball screws under extreme conditions. To validate the proposed approach, the calculated results are compared with those from previous experimental studies, confirming its effectiveness. When the ratio of the nut position to the screw length approaches 0.7, the fatigue elastic life of the ball screw achieves its maximum. An increase in screw length, load, or raceway conformity ratio leads to a decrease in fatigue elastic life. Conversely, an increase in contact angle and ball diameter enhances the fatigue elastic life.

Unveiling the topographic cue rendered by micropatterns for steering cell differentiation by using extrinsic photobiomodulation

It is known that cell culture micropatterns have the ability to facilitate stem cell differentiation induced by specialized chemical factors and different differentiation directions have different optimal micropattern shapes. In this study, by utilizing extrinsic photobiomodulation (EPM) with verteporfin as photosensitizer and light irradiation of 690 nm wavelength as a universal, unbiased, and synchronizing way of inducing differentiation of human umbilical cord Wharton's Jelly mesenchymal stem cells (WJ-MSCs), the topographic cue for cell type specification conveyed in microislands is investigated. It is found that the topographic cues are encoded in the symmetry and aspect ratio of microislands and conformation of cells to microislands is necessary for acquiring the cue. F-actin vertical columns form and cell thickness increases for cells on microislands, and the two effects are enhanced by EPM and correlate with cell differentiation. EPM treatment poises cells in a stationary state to initiate differentiation and the process of making commitment takes two days. Our findings reveal the way to fully exploit topographic cues for promoting and controlling cell differentiation.

The alginate dialdehyde crosslinking on curcumin-loaded zein nanofibers for controllable release

In this study, electrospun zein/alginate dialdehyde (AD) nanofibers were prepared by green crosslinking. The degree of crosslinking could reach 50.72 %, and the diameter of electrospun fibers ranged from 446.2 to 541.8 nm. The generation of AD and the bonding of crosslinking were further confirmed by the changes on characteristic peaks and conformational ratios in the infrared spectroscopy and secondary structure analysis. High concentrations of AD led to improved thermal stabilities, mechanical properties, and hydrophobicity. And the highly crosslinked nanofibers (Z-8) owned the highest elastic modulus (24.92 MPa), tensile strength (0.28 MPa), and elongation at break (8.14 %) among five samples. Moreover, Z-8 possessed a high swelling ratio of 5.45 g/g, and a low weight loss of 6.09 %. The samples could encapsulate curcumin efficiently and show controllable release behaviors based on different AD addition. And the oxidation resistance of nanofibers gradually improved, consistent with the release performances. This study indicated AD crosslinking favored the preparation and application of zein nanofibers, and the oxidized polysaccharide acted as the green crosslinking agent, which provided reference value for the application of polysaccharides in food-related electrospun materials.

Raman optical activity study of deuterated sugars: deuterium labelling as a tool for structural analysis.

Structural analyses using Raman optical activity (ROA) spectroscopy conventionally rely on vibrational signals in the fingerprint region ranging from 100 to 1800 cm-1. Use of deuterium labelling to observe ROA signals in the C-D stretching region provides additional information about a local structure of large molecular systems. So far, the potential of C-D stretching ROA signals for structural analysis has rarely been explored. In the present work, we synthesized model deuterated glucose monosaccharides and studied their ROA properties by employing molecular dynamics and density functional theory to interpret the spectra. A good agreement between the simulated and experimental spectra is achieved when the proper conformer ratios are considered. This shows the usefulness of ROA spectroscopy assisted by deuterium labelling for stereochemical and conformational analysis.

ANALISIS LAPORAN KEUANGAN UNTUK MENILAI KINERJA KEUANGAN PADA DINAS KEBUDAYAAN DAN PARIWISATA KABUPATEN MUSI RAWAS

The problem examined in this study is about the Financial Performance of the Culture and Tourism Office of Musi Rawas Regency in terms of Eifficiency, Eiffectiveness and Harmony Ratios. This study uses a qualitative method. Data collection techniques used are observation, interviews and documentation. The results showed that the Financial Performance of the Culture and Tourism Office of Musi Rawas Regency in terms of Efficiency Ratio, from 2017 to 2022 can be categorized as inefficient with an aveirange efficiency ratio valuei of 93,6%. The Financial Performance of the Musi Rawas Regency Culture and Tourism Office in terms of the Effectiveness Ratio, from 2017 – 2022 as a whole is in the effective criteria with an average effectiveness ratio valuei of 94%. Thei Financial Performance of the Office of Culture and Tourism of Musi Rawas Regency in terms of the Conformity Ratio, from 2017 – 2022 can be said to be compatible, with an average compatibility ratio value of 77,3%. The results of this research are expected to be useful for the Culture and Tourism Office of Musi Rawas Regency. They need to pay more attention to things that can be a potential source of income, such as paying special attention to tourist objects.

Conformations and Rearrangements of Collinolactone - Experiments and Theory on a Dynamic Cyclodecatriene.

Collinolactone A is a microbial specialized metabolite with a unique 6-10-7 tricyclic bislactone skeleton which was isolated from Streptomyces bacteria. The unusual cyclodecatriene motif features dynamic interconversions of two rotamers. Given the biological profiling of collinolactone A as neuroprotective agent, semisynthetic modifications represent an invaluable strategy to enhance its efficacy. Since understanding conformations and reactions of bioactive substances is crucial for rational structure-based design and synthesis of derivatives, we conducted computational studies on conformational behavior as well as experiments on thermal and acid induced rearrangements of the cyclodecatriene. Experimental conformer ratios of collinolactone A and its biosynthetic ketolactone precursor are well reproduced by computations at the PW6B95-D3/def2-QZVPP//r2 SCAN-3c level. Upon heating collinolactone A in anhydrous dioxane at 100 °C, three collinolactone B stereoisomers exhibiting enollactone structures form via Cope rearrangements. Our computations predict the energetic preference for a boat-like transition state in agreement with the stereochemical outcome of the main reaction pathway. Constriction of the ten-membered ring forms collinolactone C with four annulated rings and an exocyclic double bond. Computations and semisynthetic experiments demonstrate strong preference for an acid-catalyzed reaction pathway over an alternative Alder-ene route to collinolactone C with a prohibitive reaction barrier, again in line with stereochemical observations.

Does DMSO affect the conformational changes of drug molecules in supercritical CO2 Media?

This work investigated the effect of DMSO‑d6 on the conformation of lidocaine and fenamates. Using lidocaine as a model compound, the study investigated the influence of DMSO‑d6 on the conformational preferences of fenamates, which have similar fragment structures to the molecule. The NOESY spectra of mefenamic, flufenamic and tolfenamic acid were compared in a mixture of scCO2 + DMSO‑d6 at the same state parameters as lidocaine (45 °C and 9 MPa). The two-position exchange model was used to calculate the proportions of fenamate conformer groups in scCO2 + DMSO‑d6. The addition of DMSO‑d6 did not significantly alter the conformation of mefenamic acid, and the ratio of conformers was determined to be 75.3 / 24.7, which is very close to the previously measured in pure scCO2. The results showed that the addition of DMSO‑d6 did not significantly alter the conformation of lidocaine and mefenamic acid. This suggests that adding 2 %, DMSO‑d6 can be used to evaluate the structure of poorly soluble drug compounds using the NOESY method in supercritical carbon dioxide. The findings of this study are encouraging.

Low-Temperature Gas-Phase Kinetics of Ethanol-Methanol Heterodimer Formation.

The structures of gas-phase noncovalently bound clusters have long been studied in supersonic expansions. This method of study, while providing a wealth of information about the nature of noncovalent bonds, precludes observation of the formation of the cluster, as the clusters form just after the orifice of the pulsed valve. Here, we directly observe formation of ethanol-methanol dimers via microwave spectroscopy in a controlled cryogenic environment. Time profiles of the concentration of reagents in the cell yielded gas-phase reaction rate constants of kMe-g = (2.8 ± 1.4) × 10-13 cm3 molecule-1 s-1 and kMe-t = (1.6 ± 0.8) × 10-13 cm3 molecule-1 s-1 for the pseudo-second-order ethanol-methanol dimerization reaction at 8 K. The relaxation cross section between the gauche and trans conformers of ethanol was also measured using the same technique. In addition, thermodynamic relaxation between conformers of ethanol over time allowed for selection of conformer stoichiometry in the ethanol-methanol dimerization reaction, but no change in the ratio of dimer conformers was observed with changing ethanol monomer stoichiometry.

Exploring the Conformational Equilibrium of Mefenamic Acid Released from Silica Aerogels via NMR Analysis.

This study examines the influence of mefenamic acid on the physical and chemical properties of silica aerogels, as well as its effect on the sorption characteristics of the composite material. Solid state magic angle spinning nuclear magnetic resonance (MAS NMR) and high-pressure 13C NMR kinetic studies were conducted to identify the presence of mefenamic acid and measure the kinetic rates of CO2 sorption. Additionally, a high-pressure T1-T2 relaxation-relaxation correlation spectroscopy (RRCOSY) study was conducted to estimate the relative amount of mefenamic acid in the aerogel's pores, and a high-pressure nuclear Overhauser effect spectoscopy (NOESY) study was conducted to investigate the conformational preference of mefenamic acid released from the aerogel. The results indicate that mefenamic acid is affected by the chemical environment of the aerogel, altering the ratio of mefenamic acid conformers from 75% to 25% in its absence to 22% to 78% in the presence of aerogel.

Ethanolamine phospholipids at the air-water interface as cell membranes models of microorganisms to study the nanotoxicology of sakuranetin

Sakuranetin, a natural flavonoid isolated as the main compound from roots of the Brazilian plant Baccharis retusa (Asteraceae), was incorporated in lipid membranes as Langmuir monolayers. For that, the mammalian lipid dipalmitoyl phosphatidylethanolamine (DPPE) was chosen. Sakuranetin condensed the monolayers at high surface pressures, decreased the surface compression modulus and reduced the molecular order of the acyl chains (reduction of all-trans/gauche conformers ratio), and increased the heterogeneity of the interface, forming aggregates. These combined results lead to the conclusion that this lipophilic compound may interact with the lipidic layers, preferentially at the lipid-air interface, to minimize the free energy, and reaches such conformation disturbing the thermodynamic, structural, mechanical, rheological, and morphological properties of the well-packed DPPE monolayer.

Optimization of conditions for the synthesis of calyx[4]resorcinol conformers containing 4-dimethylammoniophenyl fragments on the lower rim of the molecule based on the response surface methodology using three-level box-behnken plans

The response surface methodology using three-level Box-Behnken plans was applied in order to optimize the yield of the cone and chair conformers in the synthesis of calix[4]resorcinol functionalized with 4-dimethylammoniophenyl group along the lower rim. We used data from one-factor experiments in which the temperature, reaction time, and molar ratio of HCl to the reactants of the reaction mixture were varied to plot the response surfaces. The ratio of conformers was calculated based on the analysis of 1H NMR spectra of the products isolated from the reaction mixture. The adequacy of the proposed mathematical models for determining the yields of chair and cone conformations is confirmed by a high correlation coefficient ( R 0.99979). Optimal conditions were found for the maximum yield of the chair conformation (50°C, 2 h, molar ratio of HCl to reagents in the reaction mixture is 1-1.5, yield 100%). The optimal conditions for obtaining the cone conformation are: temperature 68.6°С, stirring time in the range of 2.24-6.44 h and the molar ratio of HCl to reagents in the reaction mixture is 2. Carrying out the synthesis under these conditions leads to the yield of the cone conformation in the range of 57.70-58.07%.