Achieving the Reverse Intersystem Crossing in Chalcone Based Donor-Acceptor System through Down-Conversion of Triplet Exciton.

In recent years, understanding the mechanism of thermally activated delayed fluorescence (TADF) has become the primary choice for designing high-efficiency, low-cost, metal-free organic light emitting diodes (OLEDs). Herein, we propose a strategically designed chalcone based donor-acceptor system, where intensification of delayed fluorescence with decrease in temperature (300 K to 100 K) is observed; the theoretical investigations of electronic states and orbital characters uncovered a new cold rISC pathway in donor-acceptor system, where rISC occurs through the down-conversation of higher triplet exciton (from T3 ) to lowest singlet state (S1 ), having negative energy splitting, thus no thermal energy is required. The comprehensive research described herein might open-up new avenues in donor-acceptor system over the conventional up-convention of triplet exciton and demonstrates that not necessarily all delayed fluorescence are thermally activated (TADF).

Elucidating the G″ overshoot in soft materials with a yield transition via a time-resolved experimental strain decomposition.

Materials that exhibit yielding behavior are used in many applications, from spreadable foods and cosmetics to direct write three-dimensional printing inks and filled rubbers. Their key design feature is the ability to transition behaviorally from solid to fluid under sufficient load or deformation. Despite its widespread applications, little is known about the dynamics of yielding in real processes, as the nonequilibrium nature of the transition impedes understanding. We demonstrate an iteratively punctuated rheological protocol that combines strain-controlled oscillatory shear with stress-controlled recovery tests. This technique provides an experimental decomposition of recoverable and unrecoverable strains, allowing for solid-like and fluid-like contributions to a yield stress material's behavior to be separated in a time-resolved manner. Using this protocol, we investigate the overshoot in loss modulus seen in materials that yield. We show that this phenomenon is caused by the transition from primarily solid-like, viscoelastic dissipation in the linear regime to primarily fluid-like, plastic flow at larger amplitudes. We compare and contrast this with a viscoelastic liquid with no yielding behavior, where the contribution to energy dissipation from viscous flow dominates over the entire range of amplitudes tested.

Designing Multicomponent Polymer Colloids for Self-Stratifying Films.

Aqueous polymer colloids known as latexes are widely used in coating applications. Multicomponent latexes comprised of two incompatible polymeric species organized into a core-shell particle morphology are a promising system for self-stratifying coatings that spontaneously partition into multiple layers, thereby yielding complex structured coatings requiring only a single application step. Developing new materials for self-stratifying coatings requires a clear understanding of the thermodynamic and kinetic properties governing phase separation and polymeric species transport. In this work, we study phase separation and self-stratification in polymer films based on multicomponent acrylic (shell) and acrylic-silicone (core) latex particles. Our results show that the molecular weight of the shell polymer and heat aging conditions of the film critically determine the underlying transport phenomena, which ultimately controls phase separation in the film. Unentangled shell polymers result in efficient phase separation within hours with heat aging at reasonable temperatures, whereas entangled shell polymers effectively inhibit phase separation even under extensive heat aging conditions over a period of months due to kinetic limitations. Transmission electron microscopy is used to track morphological changes as a function of thermal aging. Interestingly, our results show that the rheological properties of the latex films are highly sensitive to morphology, and linear shear rheology is used to understand morphological changes. Overall, these results highlight the importance of bulk rheology as a simple and effective tool for understanding changes in morphology in multicomponent latex films.

The large protein 'L' of Peste-des-petits-ruminants virus exhibits RNA triphosphatase activity, the first enzyme in mRNA capping pathway.

Peste-des-petits-ruminants is a highly contagious and fatal disease of goats and sheep caused by non-segmented, negative strand RNA virus belonging to the Morbillivirus genus-Peste-des-petits-ruminants virus (PPRV) which is evolutionarily closely related to Rinderpest virus (RPV). The large protein 'L' of the members of this genus is a multifunctional catalytic protein, which transcribes and replicates the viral genomic RNA as well as possesses mRNA capping, methylation and polyadenylation activities; however, the detailed mechanism of mRNA capping by PPRV L protein has not been studied. We have found earlier that the L protein of RPV has RNA triphosphatase (RTPase), guanylyltransferase (GTase) and methyltransferase activities, and unlike vesicular stomatitis virus (VSV), follows the conventional pathway of mRNA capping. In the present work, using a 5'-end labelled viral RNA as substrate, we demonstrate that PPRV L protein has RTPase activity when present in the ribonucleoprotein complex of purified virus as well as recombinant L-P complex expressed in insect cells. Further, a minimal domain in the C-terminal region (aa1640-1840) of the L protein has been expressed in E. coli and shown to exhibit RTPase activity. The RTPase activity of PPRV L protein is metal-dependent and functions with a divalent cation, either magnesium or manganese. In addition, RTPase associated nucleotide triphosphatase activity (NTPase) of PPRV L protein is also demonstrated. This work provides the first detailed study of RTPase activity and identifies the RTPase domain of PPRV L protein.

The RNA triphosphatase domain of L protein of Rinderpest virus exhibits pyrophosphatase and tripolyphosphatase activities.

L protein of the Rinderpest virus, an archetypal paramyxovirus possesses RNA-dependent RNA polymerase activity which transcribes the genome into mRNAs as well as replicates the RNA genome. The protein also possesses RNA triphosphatase (RTPase), guanylyltransferase (GTase) and methyltransferase enzyme activities responsible for capping the mRNAs in a conventional pathway similar to that of the host pathway. Subsequent to the earlier characterization of the GTase activity of L protein and identification of the RTPase domain of the L protein, we report here, additional enzymatic activities associated with the RTPase domain. We have characterized the pyrophosphatase and tripolyphosphatase activities of the L-RTPase domain which are metal-dependent and proceed much faster than the RTPase activity. Interestingly, the mutant proteins E1645A and E1647A abrogated the pyrophosphatase and tripolyphosphatase significantly, indicating a strong overlap of the active sites of these activities with that of RTPase. We discuss the likely role of GTase-associated L protein pyrophosphatase in the polymerase function. We also discuss a possible biological role for the tripolyphosphatase activity hitherto considered insignificant for the viruses possessing such activity.

A carboxy terminal domain of the L protein of rinderpest virus possesses RNA triphosphatase activity - The first enzyme in the viral mRNA capping pathway.

The large protein L of negative-sense RNA viruses is a multifunctional protein involved in transcription and replication of genomic RNA. It also possesses enzymatic activities involved in capping and methylation of viral mRNAs. The pathway for mRNA capping followed by the L protein of the viruses in the Morbillivirus genus has not been established, although it has been speculated that these viruses may follow the unconventional capping pathway as has been shown for some viruses of Rhabdoviridae family. We had earlier shown that the large protein L of Rinderpest virus expressed as recombinant L-P complex in insect cells as well as the ribonucleoprotein complex from purified virus possesses RNA triphosphatase (RTPase) and guanylyltransferase activities, in addition to RNA dependent RNA polymerase activity. In the present work, we demonstrate that RTPase as well as nucleoside triphosphatase (NTPase) activities are exhibited by a subdomain of the L protein in the C terminal region (a.a. 1640-1840). The RTPase activity depends absolutely on a divalent cation, either magnesium or manganese. Both the RTPase and NTPase activities of the protein show dual metal specificity. Two mutant proteins having alanine mutations in the glutamic acid residues in motif-A of the RTPase domain did not show RTPase activity, while exhibiting reduced NTPase activity suggesting overlapping active sites for the two enzymatic functions. The RTPase and NTPase activities of the L subdomain resemble those of the Vaccinia capping enzyme D1 and the baculovirus LEF4 proteins.

Effects of Postactivation Potentiation enhacement on sprint and change-of-direction performance in athletes: A systematic review.

BACKGROUND: Training interventions like Resisted Sled Training, Complex Training, Plyometric training, and recently, Postactivation Potentiation Enhancement (PAPE) protocols are being employed by sportsmen for performance enhancement. Currently, there is no conclusive evidence on the effectiveness of the PAPE protocols and methods to integrate them into the training. The current systematic review aims to critically summarize the current evidence on PAPE protocols' effect on Sprint and Change of Direction (COD) performance in Athletes and study the influence of the Type of PAPE protocols, Recovery duration, Volumes, and loads of PAPE protocols. METHODS: A systematic computerized literature search was performed from December 2020 to June 2022 on the databases: MEDLINE (assessed by PubMed), CENTRAL (Cochrane Library Central Register of Controlled Trials), PeDro, and Science direct. The major criteria for inclusion were Athletes (Population) who performed PAPE protocol as Intervention before Sprint and/or COD assessment tests. The studies were individually assessed for Risk of Bias using EPHPP (Effective Public Health Practice Project) Tool. RESULTS: A total of sixteen studies were included. For Linear sprint, nine studies reported a significant PAPE effect whereas, six studies reported insignificant effects. Whereas, for COD performance, two studies reported insignificant results and one study reported significant CODS enhancements The recovery duration ranged from 15 s up to 16 min. CONCLUSION: PAPE protocols can be incorporated provided the recovery duration is of Moderate duration (3-8mins) or Individualized durations, using multiple sets (2-6), moderate-high loads (>85% 1-RM), type of protocol is Barbell Hip Thrust, Plyometrics or Unilateral biomechanically similar exercises to Running.

Design enhancement in hydroxide ion conductivity of viologen-bakelite organic frameworks for a flexible rechargeable zinc-air battery.

Quasi-solid-state rechargeable zinc-air batteries (ZABs) are suitable for the generation of portable clean energy due to their high energy and power density, safety, and cost-effectiveness. Compared to the typical alkaline aqueous electrolyte in a ZAB, polymer or gel-based electrolytes can suppress the dissolution of zinc, preventing the precipitation of undesirable irreversible zinc compounds. Their low electronic conductivity minimizes zinc dendrite formation. However, gel electrolytes suffer from capacity fade due to the loss of the volatile solvent, failing to deliver high-energy and high-power ZABs. Consequently, developing polymers with high hydroxide ion conductivity and chemical durability is paramount. We report cationic C-C bonded robust polymers with stoichiometrically controlled mobile hydroxide ions as solid-state hydroxide ion transporters. To boot, we increased the viologen-hydroxide-ion concentration through "by-design" monomers. The polymers constructed with these designer monomers exhibit a commensurate increase in their ionic conductivity. The polymer prepared with 4 OH- ion-containing monomer was superior to the one with 3 OH-. The conductivity increases from 7.30 × 10-4 S cm-1 (30 °C) to 2.96 × 10-3 S cm-1 (30 °C) at 95% RH for IISERP-POF12_OH (2_OH) and IISERP-POF13_OH (3_OH), respectively. A rechargeable ZAB (RZAB) constructed using 3_OH@PVA (polyvinyl alcohol) as the electrolyte membrane and Pt/C + RuO2 catalyst delivers a power density of 158 mW cm-2. In comparison, RZABs with a PVA interlayer provided only 72 mW cm-2. Notably, the device suffered an initial charge-discharge voltage gap of merely 0.55 V at 10 mA cm-2, which increased by only 2 mV after 50 hours of running. The battery operated at 10 mA cm-2 and worked steadily for 67 hours. We accomplished a flexible and rechargeable zinc-air battery (F-RZAB) exhibiting a maximum power density of 79 mW cm-2. This demonstration of a cationic viologen-bakelite polymer-based flexible secondary ZAB with versatile stochiometric hydroxide-ion tunability marks an important achievement in hydroxide-ion conducting solid-state electrolyte development.

Empirical evidence for economic viability of direct seeded rice in peninsular India: An action-based research.

Purpose: This study identified critical constraints in technology adoption for Direct Seeded Rice (DSR) compared with puddled transplanted rice (PTR) practices. We present the impact of DSR technology adoption on paddy yield, income generation, and cost incurred on various farm operations. Furthermore, the study investigates whether a dry DSR practice provides more economic and production benefits than a wet DSR. Methodology: We used a multi-stage sampling (from state to district-to-village-to-farmers) and conducted a face-to-face questionnaire survey to collect primary farm-level data. We collected 669 farm and household-level data and analyzed the impact of DSR and dry DSR adoption over PTR and wet DSR, respectively. Initially, the study employed probit regression analysis to identify the DSR adoption determinants. Subsequently, using the Propensity Score Matching approach, the study measures the impact of DSR adoption over PTR in terms of yield, income, and cost management. Finally, using the PSM approach, the study estimated the impact of dry DSR adoption over wet DSR. Findings: Probit estimates suggest that variables like education, membership in farmers' organizations, farm experience, institutional credit, crop insurance, off-farm income, and smartphone and television ownership positively regulate DSR adoption. The impact assessment analysis reveals that the adoption of DSR over PTR results in marginal yield improvement. However, the cost of irrigation, land preparation, and fertilization is significantly lower in DSR, resulting in an additional income of ₹5192/acre for DSR adopters. Moreover, a comparative analysis between dry DSR and wet DSR indicates that farmers can achieve ₹2467/acre by adopting dry DSR. Practical implications: Our research findings designate the necessity for implementing policies and strategies to promote the adoption of DSR among non-adopters. Besides economic benefits, adopting the DSR method can yield environmental benefits, improve soil health, mitigate soil erosion, and decrease water use.

Community perspective and healthcare assessment in malaria endemic states of India: a cross-sectional study protocol.

INTRODUCTION: India's contribution to the malaria burden was highest in South-East Asia Region in 2021, accounting for 79% of the estimated malaria cases and 83% of malaria-related deaths. Intensified Malaria Control Programme supported by Global Funds to Fight against AIDS, Tuberculosis and Malaria has deployed crucial interventions to reduce the overall burden of malaria in India. Evaluation of utilisation of malaria elimination interventions by the community and assessment of the healthcare system is underway in eleven high malaria endemic states in India. Health system preparedness for malaria elimination, logistics, and supply chain management of diagnostic kits and anti-malarial drugs in addition to the knowledge, attitude and practice of the healthcare workers is also being assessed. METHODS AND ANALYSIS: The study is being undertaken in 11 malaria endemic states with a variable annual parasite incidence of malaria. In total, 47 districts (administrative unit of malaria control operations) covering 37 976 households are to be interviewed and assessed. We present here the protocol following which the study is being undertaken at the behest and approval of Ministry of Health and Family Welfare in India. ETHICS AND DISSEMINATION: No patients were involved in the study. Study findings will be shared with Institutional ethics board of National Institute for Malaria Research New Delhi (NIMR) in a timely, comprehensive, accurate, unbiased, unambiguous and transparent manner and to the National Vector-borne Disease (Malaria) Control Programme officers and the Community public who participated. Important findings will be communicated through community outreach meetings which are existing in the Health system. Results will be informed to study participants via local fieldwork supervised by District Malaria Officers. Also findings will be published in reputed journals based on Indian Council of Medical Research (ICMR) publication policy.The ICMR-NIMR ethics committee approved the study via letter No. NIMR/ECM/2023/Feb/14 dated 24 April 2023 for version 5. All standard ethical practices will be followed.

Effects of high-intensity interval training on aerobic capacity and sports-specific skills in basketball players.

INTRODUCTION: High intensity interval training (HIIT) are widely used to improve the cardiac performance in Basketball players. The current study aims to evaluate the effectiveness of High-Intensity Interval Training on the Aerobic Capacity and sports-specific skills in basketball players. METHODS: 40 male basketball players in the age group 18-25 years were recruited after necessary ethical clearance. Athletes were categorized into two groups of 20 people each: Group 1 control group (age: 21.9 ± 2.4 years, height: 184.6 ± 12.1 cm BMI: 23 ± 3 kg/m2) and Group 2 study group with HIIT (age: 21.4 ± 2.6 years, height: 177.4 ± 6.0 cm BMI: 22.1 ± 2.3 kg/m2). The study group players underwent 5 weeks (10 sessions) of HIIT training. Pre and post intervention evaluation of the Aerobic Capacity (VO2 max) and sports-specific skills were quantified for both the groups. Statistical analysis was performed using one tailed t-test with p < 0.05 for significance. Cohen's D method was used to calculate the effect size and minimum important difference. RESULT: There was a significant increase (p < 0.05) in VO2 max (pre:52.8 ± 2.3 ml/min/kg to post: 54.5 ± 2.4 ml/min/kg) in Group 2 whereas in Group 1 the change was not significant (pre:51.1 ± 2.6 ml/min/kg to post: 51.4 ± 2.9 ml/min/kg). Similarly, there was an increase in agility for Group 2 (pre:11.0 ± 1.0 s to post: 10.1 ± 1.0 s) compared to Group 1. In sports specific skills: Control Dribble, passing skills, Lower body power and shooting skills there was a significant increase in post HIIT training for Group 2, whereas in Group 1 there was no significant difference. DISCUSSION: The HIIT training improved the aerobic capacity (VO2 max) and sports-specific skills in basketball players. CONCLUSION: A 5-week HIIT training improved the aerobic capacity and sports specific skills and may be included as a part of training regime to improve the athletic performance in basketball players.

Preferential CO2 adsorption by an ultra-microporous zinc-aminotriazolato-acetate MOF.

Ultramicroporous MOFs enable tight packing of the active functional groups, directly impacting the selective guest-framework interactions. MOFs with pores simultaneously lined by methyl and amine may serve as the ultimate humid CO2 sorbent. However, structural complexity prevents taking full advantage even in a simple zinc-triazolato-acetate layered-pillared MOF.

Transfer learning-driven ensemble model for detection of diabetic retinopathy disease.

In this study, we propose an ensemble model for the detection of diabetic retinopathy (DR) illness that is driven by transfer learning. Due to diabetes, the DR is a problem that affects the eyes. The retinal blood vessels in a person with high blood sugar deteriorate. The blood arteries may enlarge and leak as a result, or they may close and stop the flow of blood. If DR is not treated, it can become severe, damage vision, and eventually result in blindness. Medical experts study the colored fundus photos for this reason in order to manually diagnose disease, however this is a perilous technique. As a result, the condition was automatically identified utilizing retinal scans and a number of computer vision-based methods. A model is trained on one task or datasets employing the transfer learning (TL) technique, and then the pre-trained models or weights are applied to another task or dataset. Six deep learning (DL)-based convolutional neural network (CNN) models were trained in this study using huge datasets of reasonable photos, including DenseNet-169, VGG-19, ResNet101-V2, Mobilenet-V2, and Inception-V3. We also applied a data-preprocessing strategy to improve the accuracy and lower the training costs in order to improve the results. The experimental results demonstrate that the suggested model works better than existing approaches on the same dataset, with an accuracy of up to 98%, and detects the stage of DR.

Unexpected Slow Relaxation Dynamics in Pure Ring Polymers Arise from Intermolecular Interactions.

Ring polymers have fascinated scientists for decades, but experimental progress has been challenging due to the presence of linear chain contaminants that fundamentally alter dynamics. In this work, we report the unexpected slow stress relaxation behavior of concentrated ring polymers that arises due to ring-ring interactions and ring packing structure. Topologically pure, high molecular weight ring polymers are prepared without linear chain contaminants using cyclic poly(phthalaldehyde) (cPPA), a metastable polymer chemistry that rapidly depolymerizes from free ends at ambient temperatures. Linear viscoelastic measurements of highly concentrated cPPA show slow, non-power-law stress relaxation dynamics despite the lack of linear chain contaminants. Experiments are complemented by molecular dynamics (MD) simulations of unprecedentedly high molecular weight rings, which clearly show non-power-law stress relaxation in good agreement with experiments. MD simulations reveal substantial ring-ring interpenetrations upon increasing ring molecular weight or local backbone stiffness, despite the global collapsed nature of single ring conformation. A recently proposed microscopic theory for unconcatenated rings provides a qualitative physical mechanism associated with the emergence of strong inter-ring caging which slows down center-of-mass diffusion and long wavelength intramolecular relaxation modes originating from ring-ring interpenetrations, governed by the onset variable N/ND, where the crossover degree of polymerization ND is qualitatively predicted by theory. Our work overcomes challenges in achieving ring polymer purity and by characterizing dynamics for high molecular weight ring polymers. Overall, these results provide a new understanding of ring polymer physics.

COF-supported zirconium oxyhydroxide as a versatile heterogeneous catalyst for Knoevenagel condensation and nerve agent hydrolysis.

A composite of catalytic Lewis acidic zirconium oxyhydroxides (8 wt %) and a covalent organic framework (COF) was synthesized. X-ray diffraction and infrared (IR) spectroscopy reveal that COF's structure is preserved after loading with zirconium oxyhydroxides. Electron microscopy confirms a homogeneous distribution of nano- to sub-micron-sized zirconium clusters in the COF. 3D X-ray tomography captures the micron-sized channels connecting the well-dispersed zirconium clusters on the COF. The crystalline ZrOx(OH)y@COF's nanostructure was model-optimized via simulated annealing methods. Using 0.8 mol % of the catalyst yielded a turnover number of 100-120 and a turnover frequency of 160-360 h-1 for Knoevenagel condensation in aqueous medium. Additionally, 2.2 mol % of catalyst catalyzes the hydrolysis of dimethyl nitrophenyl phosphate, a simulant of nerve agent Soman, with a conversion rate of 37% in 180 min. The hydrolytic detoxification of the live agent Soman is also achieved. Our study unveils COF-stabilized ZrOx(OH)y as a new class of zirconium-based Lewis + Bronsted-acid catalysts.

Possible induction of West syndrome by oxcarbazepine therapy in a patient with complex partial seizures.

Oxcarbazepine has been reported to precipitate myoclonic, generalised tonic-clonic, absence, and complex partial seizures, and carbamazepine to precipitate absences, myoclonic seizures and spasms. Here, we report a one-year, six-month-old girl with complex partial seizures who developed infantile spasms, developmental regression, and hypsarrhythmia during the two weeks directly following initiation of oxcarbazepine (14 mg/kg/day). All of these resolved within a few days after discontinuation of this medication. Although we cannot rule out that the above association may have been coincidental, or that the improvement may have been due to concurrent therapy, this case raises the possibility that oxcarbazepine, like carbamazepine, may precipitate infantile spasms and West syndrome.

Exploring Histological Similarities Across Cancers From a Deep Learning Perspective.

Histopathology image analysis is widely accepted as a gold standard for cancer diagnosis. The Cancer Genome Atlas (TCGA) contains large repositories of histopathology whole slide images spanning several organs and subtypes. However, not much work has gone into analyzing all the organs and subtypes and their similarities. Our work attempts to bridge this gap by training deep learning models to classify cancer vs. normal patches for 11 subtypes spanning seven organs (9,792 tissue slides) to achieve high classification performance. We used these models to investigate their performances in the test set of other organs (cross-organ inference). We found that every model had a good cross-organ inference accuracy when tested on breast, colorectal, and liver cancers. Further, high accuracy is observed between models trained on the cancer subtypes originating from the same organ (kidney and lung). We also validated these performances by showing the separability of cancer and normal samples in a high-dimensional feature space. We further hypothesized that the high cross-organ inferences are due to shared tumor morphologies among organs. We validated the hypothesis by showing the overlap in the Gradient-weighted Class Activation Mapping (GradCAM) visualizations and similarities in the distributions of nuclei features present within the high-attention regions.

Biomechanics of core musculature on upper extremity performance in basketball players.

INTRODUCTION: Basketball is a dynamic team sport which involves skilled movement and activities. Shooting is considered to be an essential part of the game for scoring points. The core strength is an important preconditioning for the sport, and it influences the performance of the player. METHOD: In this study the subjects included thirty-six male basketball players divided into two groups of high and low core groups. The subjects performed one arm hop test and modified upper quarter y balance test (mUQYBT) under with and without core activation condition. The performance of the subjects was evaluated using one way analysis of variance (ANOVA) with Tukeys HSD. Statistical significance was set at p ≤ 0.05 as significant. Value of confidence interval was set at 95%. RESULTS: Based on the study, significant difference (p < 0.05) in performance for one arm hop test was observed among all the four groups of core muscles (group 1: high core with core activation, group 2 high core without core activation, group 3 low core with core activation and group 4 low core without core activation). Whereas, no significant difference (p > 0.05) in performance for mUQYBT was observed among all four groups. DISCUSSION: Core training is the basis for many functional movements and has become the norm in athletic training programs. Broad benefits of core stabilization have been overlooked, from improving athletic performance to preventing injuries in the sports medicine world. CONCLUSION: In the present study, core activation was associated with improved stability and mobility of basketball players during the upper extremity performance test, and the greatest influence of core activation was seen in individuals with lower core scores.

Stabilization of a potential anticancer thiosemicarbazone derivative in Sudlow site I of human serum albumin: In vitro spectroscopy coupled with molecular dynamics simulation.

Human Serum Albumin (HSA) is the most important protein in human blood plasma and can acts as a major transporting agent for various drug molecules with flexible binding interaction. To elucidate the interaction of a newly designed potential anticancer thiosemicarbazone based luminophore (E)-1-(4-(diethylamino)-2-hydroxybenzylidene)-4,4-dimethyl-thiosemicarbazide (DAHTS) with HSA under physiological condition, in vitro optical spectroscopic experiments viz UV-Vis absorption, steady state fluorescence, fluroscence anisotropy, time resolved fluorscence (TRF) and cicular dichroism (CD) spectroscopy have been scrutinised. The experimental findings have been corroborated with in silico molecular docking analysis and Molecular Dynamics (MD) simulation. The spectroscopic results demonstrated that the conventionally anion-favouring Sudlow site I of HSA copiously adapt neutral DAHTS molecule with moderate binding affinity. The mean fluorescence lifetime of the sole tryptophan (Trp-214) present in the macromolecule experiences an appreciable diminution with an increase in concentration of the synthesized molecule. DAHTS localize itself close to Trp-214 within subdomain IIA (Sudlow site I) and surrounded by multiple hydrophobic amino acid residues (Val-235, Val-231, Ala-229, Phe-228, Val-325, Phe-326, Leu-327, Met-329, Phe-330, Leu-331, Tyr-332, Leu-346, Leu-347, Val-482, Leu-349, Ala-350, Ala-210, Trp-214, Ala- 213 and Val-216) in HSA. The distinct fluorescence lifetime, diverse pathways and changing rate of population indicates that the rotamerisation of Trp-214 residue is controlled by the guest molecule. Sudlow site I of HSA behaves flexibly and induces an allosteric modulation in the macromolecule resulting a minor deformation in the protein secondary structure as observed in CD (observed 11% change of α-helix content) as well as in MD simulation. The integrated multi-spectroscopic research described herein provides several important information about the binding interaction of a thiosemicarbazone Schiff base with HSA, which can be very significant for thiosemicarbazone based drug designing for academia as well as industry.

Comparative evaluation of structure and characteristic of peptidyl-prolyl cis-trans isomerase proteins and their function in Salmonella Typhimurium stress responses and virulence.

Peptidyl-prolyl cis-trans isomerases (PPIase) exhibit chaperone activity and assist in protein folding by increasing the rate of cis-trans transition on proline-peptide bonds. The current study aimed to identify and characterize three genes, ppiA, ppiB, and ppiC, which encode proteins of the PPIase family in the bacterium Salmonella enterica serovar Typhimurium. Salmonella Typhimurium is a facultative intracellular zoonotic pathogen that causes food- and water-borne gastroenteritis in humans (leading to bacteremia in immune-compromised subjects). Recombinant clones for the three genes were constructed and sequenced and the sequences submitted to NCBI GenBank. Three-dimensional structures for the corresponding proteins were predicted by comparative modeling. A maximum-likelihood phylogenetic gene tree constructed for the three genes showed a low evolutionary mean diversity, indicating strong evolutionary conservation. Further, single-gene deletion mutant strains, generated for the respective genes, were observed to be more susceptible to the stationary phase of growth and heat stress conditions and showed reduced survival within macrophage cells line. The present study thus indicates that ppiA, ppiB, and ppiC genes are conserved among Salmonella genome, are critical for the growth of Salmonella Typhimurium in the examined stress conditions, and may play a role in its responses and virulence.