Sensitive Detection of Hg and l-Cysteine through Optical Asymmetry-Tuned Fluorescence Switch Off-On Behavior in N-Doped Chiral Carbon Dot.

Blue-emissive nitrogen-doped chiral carbon dots (d-NCD230 and l-NCD230) exhibiting antipodal chiroptical activity, synthesized from the thermal pyrolysis of citric acid and d/l-aspartic acid in 1:2 molar ratios, have been explored as chirality-based fluorescent turn-off/on probes for the detection of Hg and l-cysteine (l-Cys). Circular dichroism (CD) spectroscopy revealed that the chiroptical activity originates from a synergy among intrinsic chirality, chiral precursors on the NCD surface, and hybridization of lower energy levels within the embedded chiral chromophore. Quantitative analysis of optical asymmetry using the Kuhn asymmetry factor () at the CD signal of 312 nm showed a higher value for d-NCD230 (1.

Influence of Nitrogen-Doped Carbon Dots on H Radical-Mediated Au-H Formation in the Hydrogenation of 4-Nitrophenol Using NCDs-Au Nanohybrids.

The hydrogenation of 4-nitrophenol using carbon dot-stabilized gold (Au) nanoparticles is well-studied, with Au-H species known to catalyze the reaction. However, the impact of specific nitrogen moieties in nitrogen-doped carbon dots on Au-H formation and catalytic activity remains unexplored. These nitrogen species, acting as surface ligands, may influence the catalytic properties through the generation of Au-H species via H radicals.

Biocompatible fluorescent carbon nanoparticles as nanocarriers for targeted delivery of tamoxifen for regression of Breast carcinoma.

Breast cancer (BC) is the most common malignancy among females worldwide, and its high metastasis rates are the leading cause of death just after lung cancer. Currently, tamoxifen (TAM) is a hydrophobic anticancer agent and a selective estrogen modulator (SERM), approved by the FDA that has shown potential anticancer activity against BC, but the non-targeted delivery has serious side effects that limit its ubiquitous utility. Therefore, releasing anti-cancer drugs precisely to the tumor site can improve efficacy and reduce the side effects on the body.

White light emission from helically stacked humin-mimic based H-aggregates in heteroatom free carbon dots.

White light emission (WLE), particularly from heteroatom free carbon dots (CDs), is unusual. Besides, deciphering the origin of WLE from a H-aggregated molecular fluorophore in such kinds of CDs is a challenging task due to their non-fluorescent character resulting from a forbidden transition from a lower-energy excitonic state. Therefore, rigorous investigation on their elusive excited state photophysical properties along with their steady-state optical phenomena has to be carried out to shed light on the nature of distinct emissive states formed in the CDs.

Optical Asymmetry and Structural Complexity in Hierarchically Organized Chiral CuO Nanostructures: Insight into the Geometric and Crystallographic Effects on Cooperative Chirality.

Optical asymmetry and structural complexity across different length scales were realized in flower-shaped CuO nanostructures, prepared through refluxing an aqueous solution of copper acetate, sodium hydroxide, and D-tartaric acid, as well as in their toroid-like forms obtained on calcination at 600 °C. Atomic scale chirality in the flower morphology could be visualized as putative Boerdijk-Coexter-Bernal like tetrahelical fragments, while that in the toroid form could be identified as screw dislocation-driven helicity. The fraction of asymmetry in the nanostructures has been evaluated from their chiroptical responses based on Kuhn asymmetry factor () from circular dichroism (CD) spectroscopy in the entire UV-vis range.

Pyridinic-N-rich carbon dots in IFE-based Turn-off Fluorometric detection of nerve agent Mimic- Diethyl chlorophosphate and multicolor cell imaging.

Fluorometric sensors for the detection of nerve agent mimics have received a lot of interest nowadays due to their high sensitivity and selectivity, ease of operation, and real-time monitoring. Pyridinic-N-rich carbon dots (NCDs) prepared through microwave-assisted pyrolysis of l-Malic acid and urea have been explored first time in this work as a novel turn-off fluorescent probe for the sensitive and selective detection of diethyl chlorophosphate (DCP), a nerve agent mimic. The as-prepared carbon dots contained a large amount of pyridinic nitrogen on their surface, which can modulate the photoluminescence properties of the NCDs.

Role of Surface Oxygen Vacancies and Oxygen Species on CuO Nanostructured Surfaces in Model Catalytic Oxidation and Reductions: Insight into the Structure-Activity Relationship Toward the Performance.

Defect engineering, such as modification of oxygen vacancy density, has been considered as an effective approach to tailor the catalytic performance on transition-metal oxide nanostructured surfaces. The role of oxygen vacancies (O) on the surface of the as-prepared, zinnia-shaped morphology of CuO nanostructures and their marigold forms on calcination at 800 °C has been investigated through the study of model catalytic reactions of reduction of 4-nitrophenol and aerobic oxidation of benzyl alcohol. The O on the surfaces of different morphologies of CuO have been identified and quantified through Rietveld analysis and HRTEM, EPR, and XPS studies.

Bicyclo-DNA mimics with enhanced protein binding affinities: insights from molecular dynamics simulations.

DNA-protein interactions occur at all levels of DNA expression and replication and are crucial determinants for the survival of a cell. Several modified nucleotides have been utilized to manipulate these interactions and have implications in drug discovery. In the present article, we evaluated the binding of bicyclo-nucleotides (generated by forming a methylene bridge between C1' and C5' in sugar, leading to a bicyclo system with C2' axis of symmetry at the nucleotide level) to proteins.

Seq2Enz: An application of mask BLAST methodology with a new chemical logic of amino acids for improved enzyme function prediction.

Seq2Enz method is a new way to identify whether a query protein sequence is an enzyme and to assign an enzyme class to the protein sequence. The method is based on mask BLAST fortified with some novel structural-chemical properties (NCL) of the building blocks of proteins. All available reviewed enyme sequences (267,276 in number) in Uniprot/SwissProt and most recent depositions (7062) not used for training in ECPred, a state of the art software for enzyme class prediction, are taken for assessment and the results are compared with those from conventional BLAST and ECPred respectively.

Symmetric Nucleosides as Potent Purine Nucleoside Phosphorylase Inhibitors.

Nucleic acids are one of the most enigmatic biomolecules crucial to several biological processes. Nucleic acid-protein interactions are vital for the coordinated and controlled functioning of a cell, leading to the design of several nucleoside/nucleotide analogues capable of mimicking these interactions and hold paramount importance in the field of drug discovery. Purine nucleoside phosphorylase is a well-established drug target due to its association with numerous immunodeficiency diseases.

Mask blast with a new chemical logic of amino acids for improved protein function prediction.

With the exponential increase in protein sequence data, there is an urgency to acquire a knowledge of function of the millions of sequences, using automated methods with high reliability. Conventional methods for annotating a protein sequence transfer the function of a homologous sequence with known functions based on evolutionary information. Here, we present a newer way of classifying amino acids based on chemical measures and demonstrate that, when integrated with mask BLAST, the chemical properties identified outperform current classifications of amino acids as well as evolutionary measures in function detection.

Tuning of structural and optical properties with enhanced catalytic activity in chemically synthesized Co-doped MoS nanosheets.

Molybdenum disulfide (MoS) nanosheets, due to having a highly active nature, being low cost and having unique physical and chemical properties, have shown their efficacy in the catalytic reduction of nitroarenes. Doping of transition metal ions in molybdenum disulfide (MoS) nanosheets is a well-known strategy to enhance their catalytic efficiency for the reduction of nitroarenes, however, finding the optimum dopant amount is still a subject of ongoing research. Herein, we have synthesized few-layered cobalt (Co) doped MoS nanosheets with different cobalt content (2%, 4%, 6% and 8%) through the solvothermal approach, taking sodium molybdate dihydrate (NaMoO·2HO), thiourea (CHNS) and cobalt acetate tetrahydrate [Co(CHCOO)·4HO] as precursors and their catalytic performance has been affirmed by monitoring the reduction of -nitrophenol by NaBH in real time using UV-visible absorption spectroscopy.

Identification of promising molecules against MurD ligase from Acinetobacter baumannii: insights from comparative protein modelling, virtual screening, molecular dynamics simulations and MM/PBSA analysis.

Acinetobacter baumannii, an opportunistic bacterium of the multidrug-resistant (MDR) ESKAPE family of pathogens, is responsible for 2-10% infections associated with all gram-negative bacteria. The hospital-acquired nosocomial infections caused by A.baumannii include deadly diseases like ventilator-associated pneumonia, bacteremia, septicemia and urinary tract infections (UTI).

Structure based drug designing and discovery of promising lead molecules against UDP-N-acetylenolpyruvoylglucosamine reductase (MurB): A potential drug target in multi-drug resistant Acinetobacter baumannii.

According to the world health organization (WHO) reports, Acinetobacter baumannii was considered as one of the significant and first-line priority pathogens, which causes hospital-acquired nosocomial infections in human. The enzymes involved in the peptidoglycan biosynthetic pathway are critical for the survival of this bacterium. Therefore, these enzymes are ideal drug target since they are conserved among most of the species and non-homologous to human.

Prioritization of Mur family drug targets against A. baumannii and identification of their homologous proteins through molecular phylogeny, primary sequence, and structural analysis.

Background: The World Health Organization (WHO) report stated that Acinetobacter baumannii had been classified as one of the most important pathogenic bacteria causing nosocomial infection in hospital patients due to multi-drug resistance (MDR). It is vital to find out new bacterial drug targets and annotated their structure and function for the exploration of new anti-bacterial agents. The present study utilized a systematic route to prioritize the potential drug targets that belong to Mur family of Acinetobacter baumannii and identify their homologous proteins using a computational approach such as sequence similarity search, multiple sequence alignment, phylogenetic analysis, protein sequence, and protein structure analysis.

Computer aided ligand based screening for identification of promising molecules against enzymes involved in peptidoglycan biosynthetic pathway from Acinetobacter baumannii.

A. baumannii has been considered as Priority-I as suggested by the World Health Organization (WHO) and the most critical pathogenic microorganism for causing nosocomial infection in imunno-compromised hospital-acquired patients due to multi-drug resistance (MDR). In the current study, we utilized "Computer-aided ligand-based virtual screening approach" for identification of promising molecules against Mur family proteins based on the known inhibitor (Naphthyl Tetronic Acids ((5Z)-3-(4-chlorophenyl)-4-hydroxy-5-(1-naphthylmethylene) furan-2(5H)-one)) of MurB from E.

Targeting SARS-CoV-2: a systematic drug repurposing approach to identify promising inhibitors against 3C-like proteinase and 2'-O-ribose methyltransferase.

The recent pandemic associated with SARS-CoV-2, a virus of the Coronaviridae family, has resulted in an unprecedented number of infected people. The highly contagious nature of this virus makes it imperative for us to identify promising inhibitors from pre-existing antiviral drugs. Two druggable targets, namely 3C-like proteinase (3CLpro) and 2'-O-ribose methyltransferase (2'-O-MTase) were selected in this study due to their indispensable nature in the viral life cycle.

Screening of promising molecules against MurG as drug target in multi-drug-resistant- - insights from comparative protein modeling, molecular docking and molecular dynamics simulation.

The UDP--acetylglucosamine--acetylmuramyl-(pentapeptide) pyrophosphoryl-undecaprenol -acetylglucosamine transferase (MurG) is located in plasma membrane which plays a crucial role for peptidoglycan biosynthesis in Gram-negative bacteria. Recently, this protein is considered as an important and unique drug target in since it plays a key role during the synthesis of peptidoglycan as well as which is not found in In this study, initially we performed comparative protein modeling approach to predict the three-dimensional model of MurG based on crystal structure of UDP--acetylglucosamine--acetylmuramyl-(pentapeptide) pyrophosphoryl-undecaprenol N-acetylglucosamine transferase (PDB ID: 1F0K) from K12. MurG model has two important functional domains located in and terminus which are separated by a deep cleft.

Symmetrization of the backbone of nucleic acids: a molecular dynamics study.

DNA displays directional asymmetry (5'→3'), a fundamental property associated with each strand of the nucleic acids and is crucial to several biological processes such as transcription and replication. We observe that this asymmetry can be altered by a number of ways leading to directionally symmetric nucleic acids. We report six such approaches for the creation of symmetric backbones, their insertion in a regular B-DNA structure followed by their characterization using molecular dynamics (MD) simulations on a microsecond timescale in explicit solvent.

Targeting of EGFR, VEGFR2, and Akt by Engineered Dual Drug Encapsulated Mesoporous Silica-Gold Nanoclusters Sensitizes Tamoxifen-Resistant Breast Cancer.

Tamoxifen administration enhanced overall disease-free survival and diminished mortality rates in cancer patients. However, patients with breast cancer often fail to respond for tamoxifen therapy due to the development of a drug-resistant phenotype. Functional analysis and molecular studies suggest that protein mutation and dysregulation of survival signaling molecules such as epidermal growth factor receptor, vascular endothelial growth factor receptor 2, and Akt contribute to tamoxifen resistance.

A Statistical Model-driven Surgical Case Scheduling System Improves Multiple Measures of Operative Suite Efficiency: Findings From a Single-center, Randomized Controlled Trial.

Objective: We sought to determine whether a data-driven scheduling approach improves Operative Suite (OS) efficiency.

Background: Although efficient use of the OS is a critical determinant of access to health care services, OS scheduling methodologies are simplistic and do not account for all the available characteristics of individual surgical cases.

Methods: We randomly scheduled cases in a single OS by predicting their length using either the historical mean (HM) duration of the most recent 4 years; or a regression modeling (RM) system that accounted for operative and patient characteristics.

Morphological Effects of CuO Nanostructures on Fibrillation of Human Serum Albumin.

The influence of different morphologies of nanostructures on amyloid fibrillation has been investigated by monitoring the fibrillation of human serum albumin (HSA) in the presence of rod-, sphere-, flower-, and star-shaped copper oxide (CuO) nanostructures. The different morphologies of CuO have been synthesized from an aqueous solution-based precipitation method using various organic acids, viz., acetic acid, citric acid, and tartaric acid.

Micellear Gold Nanoparticles as Delivery Vehicles for Dual Tyrosine Kinase Inhibitor ZD6474 for Metastatic Breast Cancer Treatment.

The therapeutic index of poorly water-soluble drugs is often hampered due to poor pharmacokinetics, reduced blood retention, and lack of effective drug concentrations in the tumor region. In order to overcome these issues, drugs are often delivered by use of delivery vehicles to provide an enhanced therapeutic index. Gold nanoparticles synthesized in micellar networks of amphiphilic block copolymer (AuNM) provide an efficient nanocarrier for tissue- and site-specific drug delivery owing to their low cytotoxicity and immunogenicity.

Structural influences on the activity of bismuth(III) indole-carboxylato complexes towards Helicobacter pylori and Leishmania.

Seven new bismuth(III) complexes derived from indole-carboxylic acids have been synthesised: five are homoleptic; [Bi(IAA)] B1, [Bi(IPA)] B2, [Bi(IBA)] B3, [Bi(MICA)] B4, [Bi(IGA)] B6, and two are heteroleptic [BiPh(MICA)] B5 (where IAA-H=2-(1H-indol-3-yl)acetic acid, IPA-H=3-(1H-indol-3-yl)propanoic acid, IBA-H=4-(1H-indol-3-yl)butanoic acid, IGA-H=2-(1H-indol-3-yl)-2-oxoacetic acid, and MICA-H=1-methyl-1H-indole-3-carboxylic acid). All complexes were fully characterised by elemental analysis, infrared and mass-spectroscopy, and nuclear magnetic resonance (H, C) spectroscopy. Complex [BiPh(IGA)] B7 is structurally authenticated by X-ray crystallography as a dimer in the solid-state.