Peak Shift Research Articles

MURCA driven bulk viscosity in neutrino trapped baryonic matter

We examine bulk viscosity, taking into account trapped neutrinos in baryonic matter, in the context of binary neutron star mergers. Following the merging event, the binary star can yield a remnant compact object with densities up to 5 nuclear saturation density and temperature up to 50 MeV resulting in the retention of neutrinos. We employ two relativistic mean field models, NL3 and DDME2, to describe the neutrino-trapped baryonic matter. The dissipation coefficient is determined by evaluating the Modified URCA interaction rate in the dense baryonic medium, and accounting for perturbations caused by density oscillations. We observe the resonant behavior of bulk viscosity as it varies with the temperature of the medium. The bulk viscosity peak remains within the temperature range of ∼13\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim 13$$\\end{document}–50 MeV, depending upon the underlying equation of states and lepton fractions. This temperature range corresponds to the relevant domain of binary neutron star mergers. We also note that in presence of neutrinos in the medium the bulk viscosity peak shifts towards higher temperature and the peak value of bulk viscosity also changes. The time scale of viscous dissipation is dictated by the beta-off-equilibrium susceptibilities derived from the nuclear equation of state. The resulting viscous decay time scale ranges from 32–100 ms, which aligns with the order of magnitude of the post-merger object’s survival time in some specific scenarios.

Evaluation of reflective fiber-optic surface plasmon resonance sensor for monitoring scale deposition.

A reflective surface plasmon resonance (SPR) sensor was evaluated for real-time monitoring of scale deposition. The sensor consists of an optical fiber, only 5mm at the gold-coated tip of the sensing area. The effect of silica growth on the sensor response was evaluated using a Na2SiO3 solution. The sensitivity of the sensor to silica was 1.6 ± 0.3nm per one immersion in the solution of 1000mg/L (as SiO2) at 85°Cand subsequnt air drying, as indicated by theSPR peak shift. The amount of silica deposited on the gold surface was measured by the quartz crystal microbalancemethod, and the SPR sensitivity of 0.089nm/ng to silica mass was obtained. The detection limit (3σ) of the SPR sensor was 17ng, correspondingto a thickness of 2.5nm for amorphous silica. The SPR sensor wastested in geothermal brine sampled at the Sumikawa Geothermal Power Plant, where a clear SPR shift was observed, suggesting the effectiveness of the SPR sensor for scale monitoring.

Integrating machine learning with experimental investigation for optimizing photocatalytic degradation of Rhodamine B using neodymium-doped titanium dioxide: a comprehensive approach with toxicity assessment.

In this study, neodymium-doped titanium dioxide (Nd-TiO2) nanoparticles were synthesized via a hydrothermal method for the photocatalytic degradation of Rhodamine B (RhB) under UV and sunlight conditions. The properties of these NPs were comprehensively characterized. And optimization of RhB degradation was conducted using control-variable experiment and artificial neural networks (ANN) under various operational conditions and in the presence of competing compounds. The acute toxicity of both NPs, RhB, and the environmental impact of the photocatalytic treatment effluent on Danio rerio were evaluated. The Nd modification increased the catalyst's specific surface area and thermal stability. X-ray diffraction confirmed the tetragonal anatase phase in undoped TiO2, while Nd-doped TiO2 exhibited shifts in peaks and the presence of brookite and rutile phases. Nd (1mol%) doped TiO2 demonstrated superior RhB photocatalytic degradation efficiency, achieving 95% degradation and 82% total organic carbon (TOC) removal within 60min under UV irradiation. Optimization under sunlight conditions yielded 95.14% RhB removal with 0.28g/L photocatalyst and 1% doping. Under UV light, 98.12% RhB removal was optimized with 0.97% doping, along with the presence of humic acid and CaCl2. ANN modeling achieved high precision (R2 of 0.99) in modeling environmental photocatalysis. Toxicity assessments indicated that the 96-h LC50 values were 681.59mg L-1 for both NPs, and 23.02mg L-1 for RhB. The treated dye solution exhibited a significant decline in toxicity, emphasizing the potential of 1% Nd-TiO2 in wastewater treatment.

Evaluation of molecular interaction between intercellular lipid organization in human stratum corneum and terpenes using time-resolved synchrotron X-ray diffraction

The stratum corneum (SC) presents certain limitations for topical administration of medication, which can be overcome using penetration enhancers (PEs) such as terpene (TP). The SC is also crucial for maintaining the skin barrier and consists of two lamellar structures: the short periodicity phase (SPP) and long periodicity phase (LPP). In this study, we monitored changes in the X-ray diffraction peaks of the human SC, 30 min after TP application (neroridol, 1,8-cineol, and d-limonene). With the application of nerolidol, no significant changes were observed in the small-angle diffraction peak positions for the lamellar structure of SPP, but the integrated intensity decreased. On the contrary, when applying 1,8-cineole and d-limonene, a lower angle peak shift with broadening of the peak width of SPP diffraction peaks was observed for d-limonene than for 1,8-cineole, and the degree of peak shift and width broadening was greater for d-limonene than for 1,8-cineole. The diffraction peaks of LPP disappeared when 1,8-cineole and d-limonene were applied. These results indicate that the degree of interaction between the SC and TP differs depending on the molecular species, and d-limonene and 1,8-cineole exhibit penetration-enhancing via lamellar structure disruption of both SPP and LPP, immediately after application.

Improvement on the onset voltage for electroluminescent devices based in a SiOx/SiOy bilayer obtained by sputtering

Abstract This work is focused on the composition, optical and electroluminescent properties of silicon rich oxide (SiOx, x < 2) films monolayers and bilayers (SiOx/SiOy) deposited by Sputtering with silicon excess between 6.2 to 10.7 at.% were deposited on p-type (100) silicon substrates. As-deposited SiOx films emit a broad photoluminescence (PL) band where the maximum peak shifts from 420 to 540 nm as the Si-excess increases from 6.2 to 10.7 at.%, respectively. The PL intensity strongly increases and the main PL peak shifts to the red region when the SiOx films are thermally annealed. The PL emission band was dependent on silicon excess and the presence of Si-O bonds defects working as emission centers. MOS-like devices were fabricated (N+ polysilicon was used as top contact and aluminum as bottom contact) to study the EL of SiOx monolayers and SiOx/SiOy bilayers. It was found that the required voltage to obtain EL was reduced when SiOx/SiOy bilayers were used in light emitting capacitors (BLECs) as compared to those with SiOx monolayers.

Physiological response of Bidens pilosa to cadmium stress monitored by Fourier Transform Infrared Spectroscopy

The cadmium (Cd) pollution of soil causes serious environmental problems. The present paper deals with the physiological response of the changes in chemical components in the root, stem and leaf of Bidens pilosa seedlings stressed by excess cadmium ions (Cd2+) using Fourier transform infrared spectroscopy technique (FTIR). Cadmium accumulation in plant and distribution in subcellular by atomic absorption spectroscopy were tested under different concentrations cadmium stress. Results indicated that at a Cd concentration of 7 mg·L-1, B. pilosa maintained normal growth without visible Cd toxicity symptoms, though biomass was reduced compared to controls. FTIR analysis revealed that the overall peak shapes of roots, stems, and leaves remained largely unchanged before and after heavy metal treatment, suggesting that the structural integrity of plant organs was not compromised. However, shifts in specific functional group absorption peaks, including hydroxy (3387-3417 cm-1), carboxyl (1411-1419 cm-1), and amide groups (1635 cm-1), were observed, indicating their involvement in the heavy metal absorption process. The characteristic peak intensity of leaves was higher at high Cd concentration than at medium-low Cd concentration, while peaks in stems and roots remained consistent with or exceeded those of the control group. Cd predominantly accumulated in cell walls (46.21%-55.32%) and was minimally distributed in chloroplasts and mitochondria (4.11%-8.43%). These findings suggest that B. pilosa exhibits strong tolerance to Cd-contaminated soil and has significant potential for phytoremediation. The FTIR method offers strong evidence supporting the development of phytoremediation technology.

Biological synthesis of silver nanoparticles using Senna auriculata flower extract for antibacterial activities.

In this study, biological synthesis of silver nanoparticles (AgNPs) using Senna auriculata flower extract for antibacterial activities was reported. The silver spectra compared to the plant extract show a rightward shift in AgNP peaks, indicating successful nanoparticle formation. The absorption band at 302 nm and the disappearance or shift of other peaks further confirm the synthesis. X-ray diffraction (XRD) analysis reveals that the AgNPs synthesized with S. auriculata extract have an average crystallite size of 25 nm. Transmission electron microscopy (TEM) results exhibited a polydispersed, spherical shape with sizes ranging from 70 nm, in clear contrast to the electron microscope image that showed their spherical shape. When examining the selected area electron diffraction (SAED) image, a specific set of lattice planes was correlated with a specific spot. A histogram of AgNP particle size distribution can be seen. AgNPs were tested against four different strains of bacteria for their antibacterial effectiveness, including gram negative bacteria (Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus), as well as gram positive bacteria (S. aureus, d. Bacillus subtilis), at various concentrations of AgNP. The results of in vitro experiments indicate that AgNPs containing S. auriculata flowers inhibit amylase well. At two concentrations, ~16.03% and ~70.99%, AgNPs inhibit the reaction at low and high concentrations, respectively.

A study of multiple solid-state dewetting of sputtered Au ultra-thin films for chip-based LSPR sensor applications

This article proposes a lithography-free technique to fabricate Au NPs on glass substrates using multiple solid-state dewetting (SSD) of sputtered Au ultra-thin films for LSPR sensor chip applications. We studied the influence of initial film thickness and the number of repeated process cycles on the morphology and LSPR sensing performance. This fabrication process allowed control over particle size, gap spacing, and density of the Au NPs, which influenced the LSPR peak position as observed using field emission scanning electron microscopy (FE-SEM) and UV–Vis–NIR spectrophotometry. To demonstrate LSPR sensing performance, the refractive index (RI) sensitivity was evaluated by measuring the wavelength shift of the LSPR peak in a series of glycerol/phosphate-buffered saline (PBS) mixtures, varying the refractive index from 1.33909 to 1.37409. The results showed that RI sensitivity and the figure of merit (FOM) for all prepared samples ranged from 37.191 ± 12.26–73.592 ± 9.70 and 0.35 ± 0.12–0.75 ± 0.02, respectively. An increase in repeated process cycles tended to decrease RI sensitivity and FOM. The best LSPR performance was achieved with an 8 nm initial film thickness after the first cycle, with an RI sensitivity of 70.937 ± 2.60 and an FOM of 0.75 ± 0.02, attributed to optimal Au size and density. Additionally, the binding efficiency response to human IgG with high regeneration cycles was demonstrated, highlighting the potential for biosensor applications.

Raman spectroscopy combined with machine learning and chemometrics analyses as a tool for identification atherosclerotic carotid stenosis from serum

Atherosclerosis carotid stenosis (ACS) is one of the main causes of stroke. Unfortunately, the highest number of people go to the doctor with an advanced disease or as a result of a stroke, because carotid atherosclerosis does not cause obvious symptoms. Therefore, it is important to find a diagnostic method to detect the disease during routine tests (using blood or serum). Consequently, in this article, Raman spectroscopy was tested as a potential diagnostic method. Indeed, Raman spectra of serum collected from ACS and control patients showed decrease of Raman peak around 1520 cm−1 and increase of peak around 3050 cm−1 in people with ACS. Moreover in people with ACS shift of peaks originating from amides II, I and lipids vibrations were noticed in comparison with control group. Interestingly, decision tree algorithm showed that peaks at 1656 cm−1 and 2957 cm−1 could be a spectroscopy markers of atherosclerotic carotid stenosis. Continuing, Principal Component Analysis (PCA) clearly showed distinguishing between serum collected from ACS and control patients, while machine learning algorithms showed high value of accuracy, sensitivity and selectivity (more than 90 %). Finally, value of area under the curve of Receiver Operating Characteristic (AUC-ROC) showed value of 0.81 for Raman range between 800 cm−1 and 1800 cm−1 and 0.86 for 2800 cm−1–3000 cm−1 range. Obtained results clearly showed possibility of Raman spectroscopy in detection of ACS from serum.

Numerical simulation of dynamic loss and total loss in the REBCO tapes under perpendicular AC magnetic fields up to 8 T at 20 K and 50 K

REBCO tapes carry DC current under AC magnetic fields in proposed HTS fusion applications. AC loss will be generated in the process and it is important to understand the AC loss behaviour for safe operation of the fusion magnets. In this work, magnetisation loss (Qm), dynamic resistance (Rdyn), and total loss (Qtotal) in four different REBCO tapes are numerically studied, using the measured JcB,θ and nB,θ, for the magnetic field amplitude applied perpendicularly up to 8 T at 20 K and 50 K, where JcB,θ represents the magnetic field and field angle (θ) dependent critical current density. The peak of Theva JcB,θ data is different from that of other tapes. We artificially shifted the ab-plane peak of Theva JcB,θ to the left by 25° to match the peak value. The newly shifted data is named as Theva-shift, which was also investigated to study the influence of the Theva peak shift on AC loss. The normalised DC transport current level (i = It/Ic0) ranges from 0.05 to 0.9, where the DC current amplitude and the self-critical current of the tape are represented by It and Ic0, respectively. The simulation results show that the AC losses deviate significantly from the Brandt-Indenbom (BI) equation at high magnetic fields. Jc and instantaneous loss curves for different tapes show correlation at high magnetic fields. The simulation results also show how different JcB,θ characteristics for different tapes influence AC losses. When AC loss values are scaled by the self-field critical current, Qm without current and Qtotal with current in the different tapes show a good agreement. It implies that the temperature dependence of the two types of loss can be calculated from a known loss at one temperature and the self-field critical current.

Surface integrity and high-cycle fatigue life of direct laser metal deposited AISI 431 alloys modified by plasticity ball burnishing

Laser metal deposition (LMD) as an additive manufacturing (AM) is widely used to repair and extend wear and fatigue life of the critical components. This paper has investigated the application of ball burnishing (BB) to improve surface integrity and high-cycle fatigue resistance of LMDed AISI 431 alloys. Results showed that the BB treated samples exhibited significant surface finish improvement by lowering roughness by 91 %. Microhardness increased from 490 to 530 HV0.1, an increase by 10 % with a modified depth of 400 µm from the top surface. XRD results showed a peak shift and increase in FWHM by up to 17 %. This had been corroborated by EBSD exhibiting a 20 % increase in dislocation density and 24 % increase in localised misorientation within microstructure. As a result, the overall high cycle fatigue strength of the burnished sample increased by 50 %, and the cracks initiated from sub-surface level defects at a depth of 350 μm below the top surface, delaying the crack propagation and fracture failure. The findings clearly highlight that the burnishing treatment can be a plausible approach in improving the dynamic fatigue resistance and the overall service life of LMDed AISI 431 steel alloys components in engineering applications.

Novel Cosmetic Ingredient CS-AA Polyion Complex and Skin Moisturizing Effect.

The study explored the enhanced skin moisturizing capabilities and moisture retention effects achieved by forming a polyion complex using sulfated glycosaminoglycan (GAG), specifically chondroitin sulfate (CS), and amino acids (AA) such as glutamine (Q) and arginine (R). The overall hydration effect of this CS-AA complex was examined. After analyzing the CS-AA polyion complex structure using spectroscopic methods, the ex vivo moisture retention ability was assessed under dry conditions using porcine skin samples. Additionally, the efficacy of the CS-AA polyion complex in reducing transepidermal water loss (TEWL) and improving skin hydration was evaluated on human subjects using a digital evaporimeter and a corneometer, respectively. Validating a systematic reduction in particle size, the following order was observed: CS>CS/AA simple mixture>CS-AA complex based on dynamic light scattering (DLS) and transmission electron microscopy (TEM) analysis. Furthermore, observations revealed that the CS-AA complex exhibits negligible surface charge. Additionally, Fourier-transform infrared spectroscopy (FT-IR) analysis demonstrated a distinct peak shift in the complex, confirming the successful formation of the CS-AA complex. Subsequently, the water-holding effect through porcine skin was assessed, revealing a notable improvement in moisture retention (weight loss) for the CS-Q complex: 40.6% (1h), 20.5% (2h), and 18.7% (4h) compared to glycerin. Similarly, the CS-R complex demonstrated enhancements of 50.2% (1h), 37.5% (2h), and 33% (4h) compared to glycerin. Furthermore, TEWL improvement efficacy on human skin demonstrated approximately 25% improvement for both the CS-Q complex and CS-R complex, surpassing the modest 12.5% and 18% improvements witnessed with water and glycerin applications, respectively. Finally, employing a corneometer, hydration changes in the skin were monitored over 4 weeks. Although CS alone exhibited nominal alterations, the CS-Q complex and CS-R complex showed a significant increase in moisture levels after 4weeks of application. In this study, polyion complexes were successfully formed between CS, a sulfated GAG, and AA. Comparisons with glycerin, a well-known moisturizing agent, confirmed that the CS-AA complex exhibits superior moisturizing effects in various aspects. These findings suggest that the CS-AA complex is a more effective ingredient than CS or AA alone in terms of efficacy.

Influence of Germination Time on the Morphological, Structural, Vibrational, Thermal and Pasting Properties of Potato Starch from Solanum tuberosum Phureja Group

AbstractThis work focuses on the study of the physicochemical changes that take place during a short germination period in flours and starches of the Creole potato tuber. To this end, the changes in the composition of flours and the structural, thermal, vibrational, functional and pasting changes of the isolated starches from germinated potatoes were evaluated during the 12-day germination period, measured every 4 days. The water absorption index (WAI) and the swelling powder showed no significant changes. Germination resulted in a decrease in fat and ash content, but an increase in protein and amylose content. Scanning electron microscopy (SEM) showed no changes in the morphology of the starch during germination. X-ray diffraction showed that isolated Creole potato starch contains nanocrystals with hexagonal crystal structure, which are not affected by germination. Differential scanning calorimetry (DSC) shows a shift of the gelatinization peak to the right, which could be attributed to the concentration effect. The pasting profiles of the isolated starches show no significant changes, indicating that the starch granules do not suffer any external damage due to the enzymatic process during germination and that the final viscosity behaves like a hydrogel.

Elucidating refractive index sensitivity on subradiant, superradiant, and fano resonance modes in single palladium-coated gold nanorods

Herein, we investigated the distinctive scattering properties exhibited by single gold nanorods coated with palladium (AuNRs@Pd), with variations in the Pd shell thicknesses and morphologies. AuNRs@Pd were synthesized through bottom-up epitaxial Pd growth using two different concentrations of Pd precursor. These single AuNRs@Pd displayed the characteristic of subradiant and superradiant localized surface plasmon resonance peaks, characterized by a noticeable gap marked by a Fano dip. We revealed the effect of local refractive index (RI) on the subradiant and superradiant peak energies, as well as the Fano dip in the scattering spectra of AuNRs@Pd with different Pd shell thicknesses. We demonstrated the applicability of the inflection points (IFs) method on detecting peaks and dip changes across different RIs. Thin AuNRs@Pd1mM displayed more pronounced sensitivity to peak shifts in response to variations in local RIs compared to thick AuNRs@Pd2mM. In contrast, thick AuNRs@Pd2mM exhibited greater sensitivity to changes in curvature near the subradiant and superradiant peak energies rather than peak shift sensitivity across different local RIs. Moreover, the Fano dip shift was more noticeable in thick AuNRs@Pd2mM compared to thin AuNRs@Pd1mM across different local RIs. Therefore, we provided new insight into the RI sensitivity on subradiant, superradiant, and Fano resonance modes in single AuNRs@Pd.

Synthesis and characterization of Cu(II)‑meso-HMPAO complex as a model for the development of potential 64Cu radiopharmaceutical

In this work, Cu(II) complexes with meso‑HMPAO and d,l-HMPAO were synthesized. The structural characterisation of the isolated compounds has been done by single-crystal X-ray diffraction analysis, FTIR, and mass spectroscopy. Redox properties of complexes and binding to deoxyribonucleic acid (DNA) molecule have been analysed in detail by cyclic voltammetry and DFT calculations. The results of cyclic voltammetry fully agree with the data obtained by DFT calculations and indicate that the first electron removal takes place from the metal, while the second electron is removed from the ligand. The formation of the complex leads to the shift in oxidation peaks of the ligand from ‒0.29 V to 0,47 V and from 1.18 V to 1,24 V, indicating that ligand in the complex is much more difficult to oxidize. Electrochemical data confirmed the binding between the complex and DNA molecules through guanine. DFT calculations show that the complex is suitable not only for binding purine and pyrimidine bases through a coordination bond but also for additional hydrogen and CH-π interactions of the bases with the ligand. The fluorescence titration experiments revealed a moderate binding affinity of the [Cu-HMPAO]ClO4 complex to human serum albumin (HSA). Molecular docking revealed that this ligand preferentially binds to drug binding site 3 of HSA. Therefore, the novel compounds could be of great interest for further investigation, considering the potential anticancer activity, and as a model for the development of radiopharmaceutical with 64Cu.

CYP8B1 Catalyzes 12alpha-Hydroxylation of C27 Bile Acid: In Vitro Conversion of Dihydroxycoprostanic Acid into Trihydroxycoprostanic Acid.

Sterol 12α-hydroxylase (CYP8B1) is the unique P450 enzyme with sterol 12-oxidation activity, playing an exclusive role in 12α-hydroxylating intermediates along the bile acid (BA) synthesis pathway. Despite the long history of BA metabolism studies, it is unclear whether CYP8B1 catalyzes 12α-hydroxylation of C27 BAs, the key intermediates shuttling between mitochondria and peroxisomes. This work provides robust in vitro evidence that both microsomal and recombinant CYP8B1 enzymes catalyze the 12α-hydroxylation of dihydroxycoprostanic acid (DHCA) into trihydroxycoprostanic acid (THCA). On the one hand, DHCA 12α-hydroxylation reactivity is conservatively detected in liver microsomes of both human and preclinical animals. The reactivity of human tissue fractions conforms well with the selectivity of CYP8B1 mRNA expression, while the contribution of P450 enzymes other than CYP8B1 is excluded by reaction phenotyping in commercial recombinant enzymes. On the other hand, we prepared functional recombinant human CYP8B1 proteins according to a recently published protocol. Titration of the purified CYP8B1 proteins with either C4 (7α-hydroxy-4-cholesten-3-one) or DHCA yields expected blue shifts of the heme Soret peak (type I binding). The recombinant CYP8B1 proteins efficiently catalyze 12α-hydroxylation of both DHCA and C4, with substrate concentration occupying half of the binding sites of 3.0 and 1.9 μM and kcat of 3.2 and 2.6 minutes-1, respectively. In summary, the confirmed role of CYP8B1 in 12α-hydroxylation of C27 BAs has furnished the forgotten passageway in the BA synthesis pathway. The present finding might have opened a new window to consider the biology of CYP8B1 in glucolipid metabolism and to evaluate CYP8B1 inhibition as a therapeutic approach of crucial interest for metabolic diseases. SIGNIFICANCE STATEMENT: The academic community has spent approximately 90 years interpreting the synthesis of bile acids. However, the 12α-hydroxylation of intermediates catalyzed by CYP8B1 is not completely mapped on the classic pathway, particularly for the C27 bile acids, the pivotal intermediates shuttling between mitochondria and peroxisomes. This work discloses the forgotten 12α-hydroxylation pathway from dihydroxycoprostanic acid into trihydroxycoprostanic acid. The present finding may facilitate evaluating CYP8B1 inhibition as a therapeutic approach of crucial interest for metabolic diseases.

Theoretical and experimental study on combustion response of aluminized solid propellant under acceleration effects

The combustion performance of solid propellants is significantly affected by the external operating parameters of rocket motors. In this paper, the combustion response characteristics of aluminized solid propellant under acceleration conditions have been studied theoretically and experimentally. A theoretical model of unsteady burning for aluminized solid propellant, considering transient heat transfer and acceleration effects, is developed based on the Zel'dovich-Novozhilov solid-phase energy conservation. The pressure-coupled responses of the solid propellant are also measured experimentally under different normal accelerations using the T-burner and centrifuge. The model is well validated by comparison with literature and experimental results. The unsteady burning of propellants is analyzed in detail, and the effects of acceleration and propellant properties on combustion response are investigated. The results show that there is a significant difference between the transient and quasi-steady burning rate under dynamic environments. As normal acceleration increases from 0 g to 1000 g, the fluctuation amplitude of the net heat flux on the burning surface continues to decrease, the magnitude of the pressure-coupled response peak decreases significantly by 69 %, and the frequency of the response peak shifts from 140 Hz to 230 Hz. Moreover, the pressure exponent and thermal conductivity plays a positive role in the pressure-coupled response. The model presented in this paper can be helpful for predicting the differences between flight and ground test performance and evaluating the combustion stability of solid rocket motors.

SOLUBILITY ENHANCEMENT TECHNIQUE FOR BCS CLASS II DRUG - ONDANSETRON HYDROCHLORIDE BY CO-CRYSTALLIZATION METHOD

The present study was aimed to increase solubility of ondansetron hydrochloride by preparing co-crystals by co-crystallization method using various co-formers. Co-crystals of ondansetron HCl were prepared using co-formers such as benzoic acid, aspirin, benzamide, para amino benzoic acid (PABA), urea and citric acid by solvent evaporation method. Co-crystals were characterized by FTIR, DSC, XRD and SEM. The solubility of ondansetron co-crystals was significantly higher than that of pure ondansetron HCI. The dissolution rate of co-crystals reported were in the range of 63-99% compared with pure ondansetron HCl i.e., 38.70% within 30 min. The FTIR indicated a shift in the characteristic peaks of the co-crystals but did not suggest any interaction between the co-former and the drug. DSC data indicated a change in the endotherm, resulting in a new melting point of the co-crystals. The XRD spectra demonstrated the presence of different crystalline phases. Besides, SEM demonstrated the formation of different solid phase in presence of co-formers.

Boosting green hydrogen production with ZnS@MoS2 2D materials: A structural, electrochemical and photocatalytic analysis

Sustainable green hydrogen production and utilization is one of the serious options to net-zero emission and to mitigate climate change. Herein, a range of techniques has been employed to extricate structural alterations and assess electrochemical (EC) and photocatalytic (PC) properties of MoS2 and ZnS deposited MoS2 (ZnS@MoS2) 2D Materials for green hydrogen production. These 2D materials were explored via a simple hydrothermal method. X-Ray Diffraction (XRD) analysis of ZnS@MoS2 2D materials disclosed significant structural transformations, attributed to ZnS deposition, evident through peak shifts and the emergence of new peaks. Scanning electron microscopy (SEM) images revealed distinct flower-like, petal-arranged formations in MoS2 and ZnS@MoS2, while as high-resolution transmission electron microscopy (HR-TEM) images provided insights into the nanoscale structure and the d‐spacing of MoS2 and ZnS@MoS2 materials. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were utilized to determine elemental composition, chemical states, and structural characteristics. Electrochemical assessments showed that MoS2 exhibited a hydrogen evolution reaction (HER) with an onset potential of −0.3 V, whereas ZnS@MoS2 demonstrated an improved HER with an onset potential of −0.25 V (relative to Ag/AgCl). Notably, the ultra-low overpotential (η@10) of −0.40 V for MoS2 and −0.30 V for ZnS@MoS2, underlined their exceptional catalytic effectiveness. Moreover, ZnS@MoS2 material accomplished an improved photocatalytic hydrogen evolution rate of 4663.5 µmolh−1g−1, surpassing MoS2’s rate of 3318.85 µmolh−1g−1. In conclusion, it is believed that ZnS@MoS2 material can be a potential candidate for green hydrogen production, not only by splitting ultrapure water but future work will explore the catalyst’s performance in seawater electrolysis.

Click-free imaging of carbohydrate trafficking in live cells using an azido photothermal probe.

Real-time tracking of intracellular carbohydrates remains challenging. While click chemistry allows bio-orthogonal tagging with fluorescent probes, the reaction permanently alters the target molecule and only allows a single snapshot. Here, we demonstrate click-free mid-infrared photothermal (MIP) imaging of azide-tagged carbohydrates in live cells. Leveraging the micromolar detection sensitivity for 6-azido-trehalose (TreAz) and the 300-nm spatial resolution of MIP imaging, the trehalose recycling pathway in single mycobacteria, from cytoplasmic uptake to membrane localization, is directly visualized. A peak shift of azide in MIP spectrum further uncovers interactions between TreAz and intracellular protein. MIP mapping of unreacted azide after click reaction reveals click chemistry heterogeneity within a bacterium. Broader applications of azido photothermal probes to visualize the initial steps of the Leloir pathway in yeasts and the newly synthesized glycans in mammalian cells are demonstrated.