Recent advancements of smartphone-based sensing technology for diagnosis, food safety analysis, and environmental monitoring

The emergence of computationally powerful smartphones, relatively affordable high-resolution camera, drones, and robotic sensors have ushered in a new age of advanced sensible monitoring tools. The present review article investigates the burgeoning smartphone-based sensing paradigms, including surface plasmon resonance (SPR) biosensors, electrochemical biosensors, colorimetric biosensors, and other innovations for modern healthcare. Despite the significant advancements, there are still scarcity of commercially available smart biosensors and hence need to accelerate the rates of technology transfer, application, and user acceptability. The application/necessity of smartphone-based biosensors for Point of Care (POC) testing, such as prognosis, self-diagnosis, monitoring, and treatment selection, have brought remarkable innovations which eventually eliminate sample transportation, sample processing time, and result in rapid findings. Additionally, it articulates recent advances in various smartphone-based multiplexed bio sensors as affordable and portable sensing platforms for point-of-care devices, together with statistics for point-of-care health monitoring and their prospective commercial viability.

'Computational studies on coumestrol-ArlR interaction to target ArlRS signaling cascade involved in MRSA virulence'

Two component signaling system ArlRS (Autolysis-related locus) regulates adhesion, biofilm formation and virulence in methicillin resistant Staphylococcus aureus. It consists of a histidine kinase ArlS and response regulator ArlR. ArlR is composed of a N-terminal receiver domain and DNA-binding effector domain at C-terminal. ArlR receiver domain dimerizes upon signal recognition and activates DNA binding by effector domain and subsequent virulence expression. In silico simulation and structural data suggest that coumestrol, a phytochemical found in Pueraria montana, forges a strong intermolecular interaction with residues involved in dimer formation and destabilizes ArlR dimerization, an essential conformational switch required for downstream effector domain to bind to virulent loci. Structural and energy profiles of simulated ArlR-coumestrol complexes suggest lower affinity between ArlR monomers due to structural rigidity at the dimer interface hindering the conformational rearrangements relevant for dimer formation. These analyses could be an attractive strategy to develop therapeutics and potent leads molecules response regulators of two component systems in which are involved in MRSA virulence as well as other drug-resistant pathogens.Communicated by Ramaswamy H. Sarma.

In silico and structural investigation of sulfonamides targeting VraSR two component system in methicillin-resistant Staphylococcus aureus

Drug-resistant Staphylococcus aureus strains are global health concerns. Several studies have shown that these strains can develop defences against cell wall antibiotics such as β-lactams, glycopeptides and daptomycin which target cell wall biosynthesis. The coordination of these responses have been associated with two component system (TCS) regulated by histidine kinase protein (VraS) and its cognate regulator VraR which influences the target DNA upon signal recognition. Computer-based screening methods, predictions and simulations have emerged as more efficient and quick ways to identify promising new compound leads from large databases against emerging drug targets thus allowing prediction of small select set of molecules for further validations. These combined approaches conserve valuable time and resources. Due to methicillin resistance, sulfonamide-derivative medications have been found to be effective treatment strategy to treat S. aureus infections. The current study used ligand-based virtual screening (LBVS) to identify powerful sulfonamide derivative inhibitors from an antibacterial compound library against VraSR signaling components, VraS and VraR. We identified promising sulfonamide derivative [compound 5: (4-[(1-{[(3,5-Dimethoxyphenyl)Carbamoyl]Methyl}-2,4-Dioxo-1,2,3,4-Tetrahydroquinazolin-3-Yl)Methyl]-N-[(Furan-2-Yl)Methyl]Benzamide)] with reasonable binding parameters of -31.38 kJ/mol and ΔGbind score of -294.32 kJ/mol against ATP binding domain of sensor kinase VraS. We further identified four compounds N1 (PCID83276726), N3 (PCID83276757), N9 (PCID3672584), and N10 (PCID20900589) against VraR DNA binding domain (VraRC) with ΔGbind energies of -190.27, -237.54, -165.21, and -190.88 kJ/mol, respectively. Structural and simulation analyses further suggest their stable interactions with DNA interacting residues and potential to disrupt DNA binding domain dimerization; therefore, it is prudent to further investigate and characterize them as VraR dimer disruptors and inhibit other promoter binding site. Interestingly, the discovery of drugs that target VraS and VraR may open new therapeutic avenues for drug-resistant S. aureus. These predictions based on screening, simulations and binding affinities against VraSR components hold promise for opening novel therapeutic avenues against drug-resistant S. aureus and present opportunities for repositioning efforts. These efforts aim to create analogs with enhanced potency and selectivity against two-component signaling systems that significantly contribute to virulence in MRSA or VRSA. These analyses contribute valuable insights into potential avenues for combating antibiotic-resistant S. aureus through computationally driven drug discovery strategies.Communicated by Ramaswamy H. Sarma.

INF2 and ROBO2 gene mutation in an Indian family with end stage renal failure and follow-up of renal transplantation

BACKGROUND

Accurate genetic diagnosis of end-stage renal disease patients with a family history of renal dysfunction is very essential. It not only helps in proper prognosis, but becomes crucial in designating donor for live related renal transplant. We here present a case of family with deleterious mutations in INF2 and ROBO2 and its importance of genetic testing before preparing for kidney transplantation.

CASE PRESENTATION

We report the case of a 29-year-female with end-stage renal disease and rapidly progressive renal failure. Mutational analysis revealed an Autosomal Dominant inheritance pattern and mutation in exon 4 of the INF2 gene (p. Thr215Ser) and exon 26 of the ROBO2 gene (p. Arg1371Cys). Her mother was diagnosed for CKD stage 4 with creatinine level of 4.3 mg/dL. Genetic variants (INF2 and ROBO2) identified in proband were tested in her sisters and mother. Her elder sister was positive for both heterozygous variants (INF2 and ROBO2). Her mother was positive for mutation in INF2 gene, and her donor elder sister did not showed mutation in INF2 gene and had mutation in ROBO2 gene without any clinical symptoms.

CONCLUSION

This case report emphasize that familial genetic screening has allowed us in allocating the donor selection in family where family member had history of genetic defect of Chronic Kidney Disease. Information of the causative renal disorder is extremely valuable for risk-assessment and planning of kidney transplantation.

A Eu3+doped functional core-shell nanophosphor as fluorescent biosensor for highly selective and sensitive detection of dsDNA

Lanthanide-doped core-shell nanomaterials have illustrated budding potential as luminescent materials, but their biological applications have still been very limited due to their aqueous solubility and biocompatibility. Here, we report a simple and cost-effective approach to construct a water-stable chitosan-functionalized lanthanoid-based core shell (Ca-Eu:Y2O3@SiO2) nanophosphor. The as-synthesized Ca-Eu:Y2O3@SiO2-chitosan (CEY@SiO2-CH) nanophosphor has been characterized for its structural, morphological, and optical properties, by employing different analytical tools. This sensing platform is suitable for dsDNA probing by tracing the "turn on" fluorescence signal generated by CEY@SiO2-CH nanophosphor with the addition of dsDNA. The ratio of fluorescence intensity enhancement is proportional to the concentration of dsDNA in the range 0.1-90 nM, with the limit of detection at ⁓16.1 pM under optimal experimental conditions. The enhancement in fluorescence response of functionalized core-shell phosphor with dsDNA is due to the antenna effect. Additionally, response of probe has been studied for the real samples displaying percent recovery in between 101 and 105, maximum RSD% upto 5.23 (n = 3). This outcome can be applied to the selective sensing of dsDNA through optical response. These findings establish the CEY@SiO2-CH a simple, portable, and potential candidate as a sensor for rapid and analytical detection of dsDNA.

Investigating the role of glycans in Omicron sub-lineages XBB.1.5 and XBB.1.16 binding to host receptor using molecular dynamics and binding free energy calculations

Omicron derived lineages viz. BA.2, BA.3, BA.4 BA.5, BF.7 and XBBs show prominence with improved immune escape, transmissibility, infectivity, and pathogenicity in general. Sub-variants, XBB.1.5 and XBB.1.16 have shown rapid spread, with mutations embedded throughout the viral genome, including the spike protein. Changing atomic landscapes in spike contributes significantly to modulate host pathogen interactions and infections thereof. In the present work, we computationally analyzed the binding affinities of spike receptor binding domains (RBDs) of XBB.1.5 and XBB.1.16 towards human angiotensin-converting enzyme 2 (hACE2) compared to Omicron. We have employed simulations and binding energy estimation of molecular complexes of spike-hACE2 to assess the interplay of interaction pattern and effect of mutations if any in the binding mode of the RBDs of these novel mutants. We calculated the binding free energy (BFE) of the RBD of the Omicron, XBB.1.5 and XBB.1.16 spike protein to hACE2. We showed that XBB.1.5 and XBB.1.16 can bind to human cells more strongly than Omicron due to the increased charge of the RBD, which enhances the electrostatic interactions with negatively charged hACE2. The per-residue decompositions further show that the Asp339His, Asp405Asn and Asn460Lys mutations in the XBBs RBD play a crucial role in enhancing the electrostatic interactions, by acquiring positively charged residues, thereby influencing the formation/loss of interfacial bonds and thus strongly affecting the spike RBD-hACE2 binding affinity. Simulation results also indicate less interference of heterogeneous glycans of XBB.1.5 spike RBD towards binding to hACE2. Moreover, despite having less interaction at the three interfacial contacts between XBB S RBD and hACE2 compared to Omicron, variants XBB.1.5 and XBB.1.16 had higher total binding free energies (ΔGbind) than Omicron due to the contribution of non-interfacial residues to the free energy, providing insight into the increased binding affinity of XBB1.5 and XBB.1.16. Furthermore, the presence of large positively charged surface patches in the XBBs act as drivers of electrostatic interactions, thus support the possibility of a higher binding affinity to hACE2.

Entamoeba histolytica induced NETosis and the dual role of NETs in amoebiasis

Entamoeba histolytica (Eh), a microaerophilic parasite, causes deadly enteric infections that result in Amoebiasis. Every year, the count of invasive infections reaches 50 million approximately and 40,000 to 1,00,000 deaths occurring due to amoebiasis are reported globally. Profound inflammation is the hallmark of severe amoebiasis which is facilitated by immune first defenders, neutrophils. Due to size incompatibility, neutrophils are unable to phagocytose Eh and thus, came up with the miraculous antiparasitic mechanism of neutrophil extracellular traps (NETs). This review provides an in-depth analysis of NETosis induced by Eh including the antigens involved in the recognition of Eh and the biochemistry of NET formation. Additionally, it underscores its novelty by describing the dual role of NETs in amoebiasis where it acts as a double-edged sword in terms of both clearing and exacerbating amoebiasis. It also provides a comprehensive account of the virulence factors discovered to date that are implicated directly and indirectly in the pathophysiology of Eh infections through the lens of NETs and can be interesting drug targets.

"Identification of alkaloid compounds as potent inhibitors of Mycobacterium tuberculosis NadD using computational strategies"

Mycobacterium tuberculosis is leading cause of death worldwide. NAD participates in a host of redox reactions in energy landscape of organisms. Several studies implicate surrogate energy pathways involving NAD pools as important in survival of active as well as dormant mycobacteria. One of the NAD metabolic pathway enzyme, nicotinate mononucleotide adenylyltransferase (NadD) is indispensable in mycobacterial NAD metabolism and is perceived as an attractive drug target in pathogen. In this study, we have employed in silico screening, simulation and MM-PBSA strategies to identify potentially important alkaloid compounds against mycobacterial NadD for structure-based inhibitor development. We have performed an exhaustive structure-based virtual screening of an alkaloid library, ADMET, DFT profiling followed by Molecular Dynamics (MD) simulation, and Molecular Mechanics-Poisson Boltzmann Surface Area (MM-PBSA) calculation to identify 10 compounds which exhibit favourable drug like properties and interactions. Interaction energies of these 10 alkaloid molecules range between -190 kJ/mol and -250 kJ/mol. These compounds could be promising starting point in the development of selective inhibitors against Mycobacterium tuberculosis.

Is BF.7 more infectious than other Omicron subtypes: Insights from structural and simulation studies of BF.7 spike RBD variant

Fear of a fresh infection wave and a global health issue in the ongoing COVID-19 pandemic have been rekindled by the appearance of two new novel variants BF.7 and BA.4/5 of Omicron lineages. Predictions of increased antibody evasion capabilities and transmissibility have been recognised in addition to the existing lineages (BA.1.1, BA.2, BA.2.12.1 and BA.3) as cause for worry. In comparison to Omicron, BA.4 and BF.7 share nine mutations in the spike protein, Leu371Phe, Thr376Ala, Asp405Asn, Arg408Ser, Ser446Gly, Leu452Arg, Phe486Val, Arg493Gln, Ser496Gly, whereas BF.7 contains an additional mutation, Arg346Thr, in the receptor binding domain (RBD) region. Due to the critical need for analysis and data on the BA.4 and BF.7 variants, we have computationally analyzed the interaction pattern between the Omicron, BA.4 and BF.7 RBD and angiotensin-converting enzyme 2 (ACE2) to determine the influence of these unique mutations on the structures, functions, and binding affinity of RBD towards ACE2. These analyses also allow to compare molecular models to previously reported data to evaluate the robustness of our methods for quick prediction of emerging future variants. The docking results reveal that BA.4 and BF.7 have particularly strong interactions with ACE2 when compared to Omicron, as shown by several parameters such as salt bridge, hydrogen bond, and non-bonded interactions. In addition, the estimations of binding free energy corroborated the findings further. BA.4 and BF.7 were found to bind to ACE2 with similar affinities (-72.14 and - 71.54 kcal/mol, respectively) and slightly stronger than Omicron (-70.04 kcal/mol). The differences in the binding pattern between the Omicron, BA.4 and BF.7 variant complexes indicated that the BA.4 and BF.7 RBD substitutions Asp405Asn, Ser446Gly, Leu452Arg, Phe486Val and Arg493Gln caused additional interactions with ACE2. In addition, normal mode analyses also indicate more stable conformations of BA.4 and BF.7 RBDs against human ACE2. Based on these structural and simulation analyses, we hypothesized that these changes may affect the binding affinity of BA.4 and BF.7 with ACE2.

Effect of endogenous hormones, antisperm antibody and oxidative stress on semen quality of crossbred bulls

The present study was designed to evaluate the effect of factors like hormones, antisperm antibody (ASA), and oxidative stress and its relation with semen quality in crossbred bulls. Ejaculates from two bulls were categorized into good (n = 12) and poor (n = 12) based on initial progressive motility, that is, ≥70% and ≤50%, respectively. The level of hormones like Testosterone (p < 0.05) and PGE₂ (p < 0.01) was significantly higher in good-quality ejaculates compared to poor-quality ejaculates; however, estradiol (p < 0.05), progesterone, oxidative stress, and ASAs were significantly higher (p < 0.01) in poor-quality ejaculates compared to good-quality ejaculates. Therefore, it could be concluded that oxidative stress and hormonal imbalance might have resulted in high number of dead and defective spermatozoa which was ultimately responsible for poor quality semen ejaculates.

Development of a novel Bruton's tyrosine kinase inhibitor that exerts anti-cancer activities potentiates response of chemotherapeutic agents in multiple myeloma stem cell-like cells

Despite recent improvements in multiple myeloma (MM) treatment, MM remains an incurable disease and most patients experience a relapse. The major reason for myeloma recurrence is the persistent stem cell-like population. It has been demonstrated that overexpression of Bruton's tyrosine kinase (BTK) in MM stem cell-like cells is correlated with drug resistance and poor prognosis. We have developed a novel small BTK inhibitor, KS151, which is unique compared to other BTK inhibitors. Unlike ibrutinib, and the other BTK inhibitors such as acalabrutinib, orelabrutinib, and zanubrutinib that covalently bind to the C481 residue in the BTK kinase domain, KS151 can inhibit BTK activities without binding to C481. This feature of KS151 is important because C481 becomes mutated in many patients and causes drug resistance. We demonstrated that KS151 inhibits in vitro BTK kinase activities and is more potent than ibrutinib. Furthermore, by performing a semi-quantitative, sandwich-based array for 71-tyrosine kinase phosphorylation, we found that KS151 specifically inhibits BTK. Our western blotting data showed that KS151 inhibits BTK signaling pathways and is effective against bortezomib-resistant cells as well as MM stem cell-like cells. Moreover, KS151 potentiates the apoptotic response of bortezomib, lenalidomide, and panobinostat in both MM and stem cell-like cells. Interestingly, KS151 inhibits stemness markers and is efficient in inhibiting Nanog and Gli1 stemness markers even when MM cells were co-cultured with bone marrow stromal cells (BMSCs). Overall, our results show that we have developed a novel BTK inhibitor effective against the stem cell-like population, and potentiates the response of chemotherapeutic agents.

"In silico identification of ethoxy phthalimide pyrazole derivatives as IL-17A and IL-18 targeted gouty arthritis agents"

Two proinflammatory cytokines, IL17A and IL18, are observed to be elevated in the serum of gout patients and they play a crucial role in the development and worsening of inflammation, which has severe effects. In present study, we have combined molecular docking, molecular dynamics studies and MM-PBSA analysis to study the effectiveness of ethoxy phthalimide pyrazole derivatives (series 3a to 3e) as potential inhibitors against cytokines IL17A and IL18 as a druggable targets. The binding energy of the docked series ranges from -13.5 to -10.0 kcal/mol and extensively interacts with the amino acids in the active pocket of IL17A and IL18. Compound 3e had the lowest binding energy with IL17A at -12.6 kcal/mol compared to control allopurinol (3.32 kcal/mol). With IL18, compound 3a seems to have the lowest binding energy of -9.6 kcal/mol compared to control allopurinol (3.18 kcal/mol). In MD simulation studies, compound 3a forms a stable and energetically stabilized complex with the target protein. Depending on properties of the bound IL17A-3a and IL18-3a complexes was compared by means of MM-PBSA analysis. These derivatives can be used as a scaffold to develop promising IL17A and IL18 inhibitors to assess their potential for gouty arthritis and other related diseases.

Local magnetic behaviour of highly disordered undoped and Co-doped Bi2Se3 nanoplates: a muon spin relaxation study

Magnetism induced by defects in nominally non-magnetic solids has attracted intense scientific interest in recent years. The local magnetism in highly disordered undoped and Co-doped topological insulator (TI) Bi₂Se₃nanoplates has been investigated by muon spin relaxation (μSR). UsingμSR spectroscopy, together with other macroscopic characterizations, we find that these nanoplates are composed of a core with both static fields and dynamically fluctuating moments, and a shell with purely dynamically fluctuating moments. The fluctuations in the core die out at low temperatures, while those in the shell continue till 2 K. When Bi₂Se₃is doped with Co, the static magnetic component increases, whilst keeping the dual (static-plus-dynamic) nature intact. The findings indicate that highly disordered TI's could constitute a new class of promising magnetic materials that can be engineered by magnetic impurity doping.

Structural and molecular dynamics of ammonia transport in Staphylococcus aureus NH3-dependent NAD synthetase

Ammonia dependent NAD⁺ synthetase from multi drug resistance Staphylococcus aureus catalyzes ATP dependent formation of NAD⁺ from deamido-NAD⁺ and ammonia at the synthetase active site. Binding of ATP accompanies a large movement of flexible loop region (205-225) acting as a lid to the catalytic core. A 17 Å long ammonia tunnel with an entry and exit radius of 3.5 Å and 3.2 Å respectively allows transfer of ammonia from surface to the active site of the enzyme in each monomer to attack the C7N=O7N linkage of transient intermediate NAD-adenylate thus releasing NAD⁺. In this study, we report structural details of ammonia transport tunnel in Staphylococcus aureus NH₃-dependent NAD synthetase and compared their architecture and dynamics with other bacterial and eukaryotic enzymes. Tunnel shows conformational variations in apo and substrate complexes and is less intricate compared to glutamine dependent counterparts. We have also performed steered molecular dynamic simulations of ammonia transport across the tunnel in enzyme-intermediate complex which reveals critical bottleneck residues and structural determinants during ammonium migration. Ordered water molecules and conserved charged residues form a network of hydrogen bonds and electrostatic interaction which facilitate the ammonium movement towards the active center. Analysis of the sMD simulated structural snapshots delineates the conformational reshaping of ammonia tunnel at the different step of the enzymatic reaction. Tunnel architecture and environment could offer the new target site to design novel small molecule inhibitors for the development of more efficient therapeutics against multi drug resistant S. aureus strains.

Synthesis of high luminescent Eu3+ doped nanoparticle and its application as highly sensitive and selective detection of Fe3+ in real water and human blood serum

The present work reports a highly efficient Ca doped Eu: Y₂O₃ i.e Ca_0.05Eu_0.01Y_1.94O₃ (CEY.) nanophosphor material synthesized through a facile combustion method, as a simple and selective turn-off fluorescence probe for the quantitative analysis of iron ions (Fe³⁺). The proposed sensor allows the quantification of iron in the range of 10 µM-90 µM with a limit of detection (LOD) ∼ 63.2 nM under the natural pH range. Moreover, CEY nanophosphor shows an excellent fluorescence phenomenon with a gradual increase in the Fe³⁺ ion concentration. It has been observed that the corresponding PL intensity gets completely quenched with 500 µM Fe³⁺ ion concentration. Furthermore, the applicability of the sensor as an efficient probe has been investigated with real water samples, iron tablets, and human blood serum (HBS). The selectivity of the probe has also been analyzed with various metal ions and biomolecules. Thus, in turn, the as-obtained sensing probe illustrates an excellent accuracy, sensitivity, and selectivity, and offers potential application in clinical diagnosis, biological and real water sample studies, with the detection of Fe³⁺ ion. Furthermore, it does not require any acidic medium for a level-free, and non-enzymic detection of a real sample with almost not affecting the sample quality and henceforth provides more reliable results.

Electrochemical sensing of pioglitazone hydrochloride on N-doped r-GO modified commercial electrodes

In this paper, we explain the electrochemical sensing of commercially available pioglitazone hydrochloride (PIOZ) tablets on a nitrogen (N) doped r-GO (Nr-GO) modified commercial glassy carbon electrode (GCE) and a commercial screen printed graphite electrode (SPGE). Nr-GO is synthesized by the chemical reduction of graphene oxide (GO) and simultaneous insertion of an N-dopant by hydrazine monohydrate. Pristine GO itself is prepared by chemical exfoliation of bulk graphite. Upon chemical reduction, the exfoliated GO sheets restack together leaving behind the doped N-atom as evidenced by XRD and Raman spectroscopy. The N-atom exists in the pyrrolinic and pyridinic form at the edge of graphitic domains which is confirmed by XPS. The as-synthesized Nr-GO is used for the preparation of electro-active electrodes with the help of the GCE and SPGE. These electrodes have the capability to oxidize PIOZ by a diffusion dominated process as evidenced by the impedance spectroscopic technique. The differential pulse voltammetric responses of different concentrations of PIOZ are assessed over the Nr-GO modified GCE and SPGE, which exhibit better limits of detection (LODs) of 67 nM and 29 nM, respectively, compared to those from earlier reports. These assays exhibit non-interfering capability in the presence of various body interferents at pH = 7.0.

Tagetes erecta as an organic precursor: synthesis of highly fluorescent CQDs for the micromolar tracing of ferric ions in human blood serum

The present article illustrates the green synthesis of novel carbon quantum dots (CQDs) from biomass viz. Tagetes erecta (TE), and subsequently fabrication of a metal ion probe for the sensing of Fe³⁺ in real samples. TE-derived CQDs (TE-CQDs) have been synthesized by a facile, eco-friendly, bottom-up hydrothermal approach using TE as a carbon source. The successful synthesis and proper phase formation of the envisaged material has been confirmed by various characterization techniques (Raman, XRD, XPS, TEM, and EDS). Notably, the green synthesized TE-CQDs show biocompatibility, good solubility in aqueous media, and non-toxicity. The as-synthesized TE-CQDs show an intense photoluminescence peak at 425 nm and exhibit excitation dependent photoluminescence behavior. The proposed TE-CQD-based probe offers a remarkable fluorescence (FL) quenching for Fe³⁺ with high selectivity (K_q ∼ 10.022 × 10¹³ M⁻¹ s⁻¹) and a sensitive/rapid response in a linear concentration range 0–90 μM (regression coefficient R² ∼ 0.99) for the detection of Fe³⁺. The limit of detection (LOD) of the probe for Fe³⁺ has been found as 0.37 μM in the standard solution. It has further been applied for the detection of Fe³⁺ in real samples (human blood serum) and displays good performance with LOD ∼ 0.36 μM. The proposed TE-CQD-based ion sensing probe has potential prospects to be used effectively in biological studies and clinical diagnosis.

TE-CQDs synthesized via the hydrothermal method for the detection of Fe³⁺ in HBS.

In Situ Fabrication of Activated Carbon from a Bio-Waste Desmostachya bipinnata for the Improved Supercapacitor Performance

Herein, we demonstrate the fabrication of highly capacitive activated carbon (AC) using a bio-waste Kusha grass (Desmostachya bipinnata), by employing a chemical process followed by activation through KOH. The as-synthesized few-layered activated carbon has been confirmed through X-ray powder diffraction, transmission electron microscopy, and Raman spectroscopy techniques. The chemical environment of the as-prepared sample has been accessed through FTIR and UV-visible spectroscopy. The surface area and porosity of the as-synthesized material have been accessed through the Brunauer-Emmett-Teller method. All the electrochemical measurements have been performed through cyclic voltammetry and galvanometric charging/discharging (GCD) method, but primarily, we focus on GCD due to the accuracy of the technique. Moreover, the as-synthesized AC material shows a maximum specific capacitance as 218 F g^-1 in the potential window ranging from - 0.35 to + 0.45 V. Also, the AC exhibits an excellent energy density of ~ 19.3 Wh kg^-1 and power density of ~ 277.92 W kg^-1, respectively, in the same operating potential window. It has also shown very good capacitance retention capability even after 5000th cycles. The fabricated supercapacitor shows a good energy density and power density, respectively, and good retention in capacitance at remarkably higher charging/discharging rates with excellent cycling stability. Henceforth, bio-waste Kusha grass-derived activated carbon (DP-AC) shows good promise and can be applied in supercapacitor applications due to its outstanding electrochemical properties. Herein, we envision that our results illustrate a simple and innovative approach to synthesize a bio-waste Kusha grass-derived activated carbon (DP-AC) as an emerging supercapacitor electrode material and widen its practical application in electrochemical energy storage fields.

Association of the microbiome with colorectal cancer development (Review)

Colorectal cancer (CRC) is the second most common malignancy causing cancer‑related mortality globally. It is the third most common type of cancer detected worldwide. The recent concept of the human body supporting a diverse community of microbes has revealed the important role these microbes play synergistically in maintaining normal homeostasis. The balance between the microbiomes and epithelial cells of the human body is essential for normal physiology. Evidence from meta‑genome analysis indicates that an imbalance in the microbiome is prominent in the guts of patients with CRC. Several studies have suggested that the gut microbiota can secrete metabolites [short‑chain fatty acids (SCFAs), vitamins, polyphenols and polyamines] that modulate the susceptibility of the colon and rectum by altering inflammation and DNA damage. The state of microbiome imbalance (dysbiosis) has been reported in patients with CRC, with an increasing population of 'bad' microbes and a decrease in 'good' microbes. The 'good' microbes, also known as commensal microbes, produce butyrate; however, 'bad' microbes cause a pro‑inflammatory state. The complex association between pathological microbial communities leading to cancer progression is not yet fully understood. An altered microbial metabolite profile plays a direct role in CRC metabolism. Furthermore, diet plays an essential role in the risk of gastrointestinal cancer development. High‑fiber diets regulate the gut microbiome and reduce the risk of CRC development, and may be fruitful in the better management of therapeutics. In the present review, the current status of the microbiome in CRC development is discussed.12.

Emerging trends in colorectal cancer: Dysregulated signaling pathways (Review)

Colorectal cancer (CRC) is the third most frequently detected type of cancer, and the second most common cause of cancer‑related mortality globally. The American Cancer Society predicted that approximately 147,950 individuals would be diagnosed with CRC, out of which 53,200 individuals would succumb to the disease in the USA alone in 2020. CRC‑related mortality ranks third among both males and females in the USA. CRC arises from 3 major pathways: i) The adenoma‑carcinoma sequence; ii) serrated pathway; and iii) the inflammatory pathway. The majority of cases of CRC are sporadic and result from risk factors, such as a sedentary lifestyle, obesity, processed diets, alcohol consumption and smoking. CRC is also a common preventable cancer. With widespread CRC screening, the incidence and mortality from CRC have decreased in developed countries. However, over the past few decades, CRC cases and mortality have been on the rise in young adults (age, <50 years). In addition, CRC cases are increasing in developing countries with a low gross domestic product (GDP) due to lifestyle changes. CRC is an etiologically heterogeneous disease classified by tumor location and alterations in global gene expression. Accumulating genetic and epigenetic perturbations and aberrations over time in tumor suppressor genes, oncogenes and DNA mismatch repair genes could be a precursor to the onset of colorectal cancer. CRC can be divided as sporadic, familial, and inherited depending on the origin of the mutation. Germline mutations in APC and MLH1 have been proven to play an etiological role, resulting in the predisposition of individuals to CRC. Genetic alterations cause the dysregulation of signaling pathways leading to drug resistance, the inhibition of apoptosis and the induction of proliferation, invasion and migration, resulting in CRC development and metastasis. Timely detection and effective precision therapies based on the present knowledge of CRC is essential for successful treatment and patient survival. The present review presents the CRC incidence, risk factors, dysregulated signaling pathways and targeted therapies.

Crystallographic and molecular dynamics simulation analysis of NAD synthetase from methicillin resistant Staphylococcus aureus (MRSA)

NAD synthetase (NadE) catalyzes the last step in NAD biosynthesis, transforming deamido-NAD⁺ into NAD⁺ by a two-step reaction with co-substrates ATP and amide donor ammonia. In this study, we report the crystal structure of Staphylococcus aureus NAD synthetase enzyme (saNadE) at 2.3 Å resolution. We used this structure to perform molecular dynamics simulations of apo-enzyme, enzyme-substrate (NadE with ATP and NaAD) and enzyme-intermediate complexes (NadE with NaAD-AMP) to investigate key binding interactions and explore the conformational transitions and flexibility of the binding pocket. Our results show large shift of N-terminal region in substrate bound form which is important for ATP binding. Substrates drive the correlated movement of loop regions surrounding it as well as some regions distal to the active site and stabilize them at complex state. Principal component analysis of atomic projections distinguish feasible trajectories to delineate distinct motions in enzyme-substrate to enzyme-intermediate states. Our results suggest mixed binding involving dominant induced fit and conformational selection. MD simulation extracted ensembles of NadE could potentially be utilized for in silico screening and structure based design of more effective Methicillin Resistant Staphylococcus aureus (MRSA) inhibitors.

Phase stability and the effect of lattice distortions on electronic properties and half-metallic ferromagnetism of Co2FeAl Heusler alloy: anab initiostudy

Density functional theory calculations within the generalized gradient approximation are employed to study the ground state of Co2FeAl. Various magnetic configurations are considered to find out its most stable phase. The ferromagnetic ground state of the Co2FeAl is energetically observed with an optimized lattice constant of 5.70 Å. After that, the system was subjected under uniform and non-uniform strains, to see their effects on spin polarization (P) and half-metallicity. The effect of spin-orbit coupling is considered in the present study. Half-metallicity (and 100%P) is retained only under uniform strains started from 0 to +4%, and dropped rapidly from 90% to 16% for the negative strains started from -1% to -6%. We find that the present system is much sensitive under tetragonal distortions as half-metallicity (and 100%P) is preserved only for the cubic case. The main reason for the loss of half-metallicity is due to the shift of the bands with respect to the Fermi level (EF). We also discuss the influence of these results on spintronics devices.

The fabrication of an MoS2 QD-AuNP modified screen-printed electrode for the improved electrochemical detection of cefixime

Herein, we report a voltammetric method for the nanomolar detection of cefixime, a third-generation antibiotic. The determination of cefixime is validated on a glassy carbon electrode (GCE) as well as on a screen-printed carbon electrode (SPCE). In the present study, we have reported a facile "one step simple hydrothermal synthesis" of MoS2 quantum dots and with the oxidation of aurochloric acid for the further formation of an MoS2 QD-AuNP composite. The as-synthesized nanocomposite was characterized via UV-Vis spectroscopy, FTIR spectroscopy, XRD, TEM and EDX techniques, and further applied in the modification of working electrodes, showing excellent electroactivity. The sensing of cefixime was done via cyclic and differential pulse voltammetry techniques. The presence of the only anodic peak in the voltammogram reveals the irreversible oxidation of cefixime in the potential range of about 1.3 ± 0.1 V vs. Ag/AgCl. The study was also performed at different scan rates, which indicate a diffusion-controlled mechanism. The proposed cefixime sensor showed a linear response in the concentration range of 0.33-90.82 μM (at S/N = 3) with a limit of detection (LOD) of 3.9-4.5 nm. The electrochemical sensitivity is calculated as 8.63 μA μM-1 cm-2 and 7.07 μA μM-1 cm-2 in buffer and pharmaceutical formulation (commercially available cefixime tablet), respectively. The effects of several interferents were also investigated. The proposed sensor is effectively used for estimating cefixime in phosphate buffer and the commercially available cefixime tablets with no cross-reactivity or matrix effects and shows a promising prospect for real applications.

Selective photoresponse of plasmonic silver nanoparticle decorated Bi2Se3 nanosheets

The plasmon-enhanced photoresponse properties of a Ag nanoparticle decorated Bi₂Se₃ nanosheet (AGBS)/p-Si heterojunction device have been studied. The Ag nanoparticles, Bi₂Se₃ nanosheets, and AGBS nanocomposite are synthesized chemically. Microscopic investigations, ultimately of the AGBS nanocomposite, reveal that the Bi₂Se₃ nanosheets of thickness ∼20 nm and lateral dimension ∼1 μm are decorated with Ag nanoparticles of sizes 20-40 nm in the nanocomposite. The x-ray diffraction pattern of AGBS shows that apart from being in a metallic state, the Ag in the AGBS is also in the form of compounds with Bi, Se, and additionally O. This observation is further complemented by the x-ray photoelectron spectrum, which shows the presence of Ag⁰ and Ag⁺ states of Ag in AGBS. The UV-visible absorption spectra show the plasmonic peak of the Ag nanoparticles occurs at 420 nm; the peak is shifted to ∼500 nm in AGBS due to the modified dielectric environment of the nanoparticles. The AGBS/p-Si heterojunction shows excellent photoresponse properties, with a responsivity of 0.28 A/W, a fairly high detectivity of 4 × 10¹⁰ Jones, and an EQE of 71% under 10 V reverse bias at a 500 nm wavelength. The plasmon enhanced photoresponse at the selective wavelength makes this material attractive for high performance optoelectronic devices.

Assessing a thermal spike model of swift heavy ion-matter interactions via Pd1-xNix/Si interface mixing

The thermal spike model (TSM), a widely accepted mechanism of swift heavy ion (SHI)-matter interactions, provides explanation for various SHI induced effects, including mixing across interfaces. We assess the validity of the model via tuning the electron-phonon coupling strength (G) by taking a series Pd_1-xNi_x of a completely solid soluble binary, and then observing Pd_1-xNi_x/Si interface mixing induced by a combination of 100 MeV Au ion irradiation and 4 keV Ar ion sputtering. If the TSM truly describes the SHI-matter interaction mechanism, any non-linearity in x-variation of G must also result in a similar non-linearity in the x-dependence of mixing. Experimentally, the extent of mixing has been parametrized by the irradiation induced change Δσ² in variances of Pd and Ni depth profiles derived from XPS. Computationally, G determined using density functional theory has been used to solve the equations appropriate to the TSM, and then an equivalent quantity L², proportional to Δσ², has been calculated. Both Δσ²(x) and L²(x) show non-linearities, albeit in slightly dissimilar ways, leading to a conjecture that the present work at least does not invalidate the TSM.

The Impact of Spiritual Intelligence, Gender and Educational Background on Mental Health Among College Students

The present study is conducted on 300 PG-level college students in Haridwar, Uttarakhand (India). The aim of the present study is to examine the level of spiritual intelligence and mental health, to observe relationship between these two variables and also to identify the difference in spiritual intelligence and mental health across gender and educational background (arts and science). The purposive sampling technique is used to select 300 college students of both disciplines of arts and science from the four different government degree colleges/campuses in Haridwar. Integrated Spiritual Intelligence Scale and Mithila Mental Health Status Inventory are used to observe the level of these variables among college students. In the present study, correlational design is employed. All the statistical analyses are done with the help of computer software SPSS. To observe relationship Pearson correlation and to identify the difference t test are used. Findings of the study revealed that spiritual intelligence and mental health relate significantly among arts students, and male and female arts students separately have significant relationship between spiritual intelligence and mental health. Spiritual intelligence and mental health relate significantly among science students, and male and female science students separately have significant relationship between spiritual intelligence and mental health. No significant difference is found between male and female students in terms of spiritual intelligence. No significant difference is found between arts and science students in terms of spiritual intelligence. No significant difference is found between male and female students in terms of mental health. No significant difference is found between arts and science students in terms of mental health.

Leishmania donovani reduces the levels of retinoic acid-synthesizing enzymes in infected macrophages and favoring its own survival

People suffering from malnutrition become susceptible to the infection like Leishmania sp., as it results in a compromised immune response. Retinoic acid (RA), an important constituent of nutrition, shows an immune-modulatory activity. However, its role in the containment of infection is not yet ascertained, particularly in case of visceral leishmaniasis (VL). VL patients (n = 10) and healthy endemic controls (n = 9) were recruited to measure the serum levels of RA. An in vitro model of Leishmania infection using the murine mφ cell line J774.1 was used to investigate the RA-synthesizing enzymes (RALDH-1 and RALDH-2). Parasite loads among infected mφ were measured by quantitative expression of kDNA in the presence of an inhibitor of the RALDH-2 enzyme. We found a significant decrease in the serum levels of RA in VL cases. Importantly, we observed decreased levels of RALDH-1 and RALDH-2 among L. donovani-infected mφ along with simultaneous decrease as well as increase in the Th-1 and Th-2-associated factors, respectively. Furthermore, the pretreatment of mφ with an RALDH-2 inhibitor improved parasite in vitro infection. Our findings show impaired RA pathway among infected mφ and indicate that an intact RA pathway is critical for anti-Leishmania immune response. Graphical abstract ᅟ.

A comparative Study of Aptasensor Vs Immunosensor for Label-Free PSA Cancer Detection on GQDs-AuNRs Modified Screen-Printed Electrodes

Label-free and sensitive detection of PSA (Prostate Specific Antigen) is still a big challenge in the arena of prostate cancer diagnosis in males. We present a comparative study for label-free PSA aptasensor and PSA immunosensor for the PSA-specific monoclonal antibody, based on graphene quantum dots-gold nanorods (GQDs-AuNRs) modified screen-printed electrodes. GQDs-AuNRs composite has been synthesized and used as an electro-active material, which shows fast electron transfer and catalytic property. Aptamer or anti-PSA has immobilized onto the surface of modified screen printed electrodes. Three techniques are used simultaneously, viz. cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedence spectroscopy (EIS) to investigate the analytical performance of both PSA aptasensor and PSA immunosensor with its corresponding PSA antigen. Under optimum conditions, both sensors show comparable results with an almost same limit of detection (LOD) of 0.14 ng mL-1. The results developed with aptasensor and anti-PSA is also checked through the detection of PSA in real samples with acceptable results. Our study suggests some advantages of aptasensor in terms of better stability, simplicity and cost effectiveness. Further our present work shows enormous potential of our developed sensors for real application using voltammetric and EIS techniques simultaneous to get reliable detection of the disease.

Remote sensing based deforestation analysis in Mahanadi and Brahmaputra river basin in India since 1985

Land use and land cover (LULC) change has been recognized as a key driver of global climate change by influencing land surface processes. Being in constant change, river basins are always subjected to LULC changes, especially decline in forest cover to give way for agricultural expansion, urbanization, industrialization etc. We used on-screen digital interpretation technique to derive LULC maps from Landsat images at three decadal intervals i.e., 1985, 1995 and 2005 of two major river basins of India. Rain-fed, Mahanadi river basin (MRB) attributed to 55% agricultural area wherein glacier-fed, Brahmaputra river basin (BRB) had only 16% area under agricultural land. Though conversion of forest land for agricultural activities was the major LULC changes in both the basins, the rate was higher for BRB than MRB. While water body increased in MRB could be primarily attributed to creation of reservoirs and aquaculture farms; snow and ice melting attributed to creation of more water bodies in BRB. Scrub land acted as an intermediate class for forest conversion to barren land in BRB, while direct conversion of scrub land to waste land and crop land was seen in MRB. While habitation contributed primarily to LULC changes in BRB, the proximity zones around habitat and other socio-economic drivers contributed to LULC change in MRB. Comparing the predicted result with actual LULC of 2005, we obtained >97% modelling accuracy; therefore it is expected that the Dyna-CLUE model has very well predicted the LULC for the year 2025. The predicted LULC of 2025 and corresponding LULC changes in these two basins acting as early warning, and with the past 2-decadal change analysis this study is believed to help the land use planners for improved regional planning to create balanced ecosystem, especially in a changing climate.

Paratesticular Paraganglioma with Metastasis to D1 Vertebra- A Case Report and Review of Literature

INTRODUCTION

Paragangliomas are relatively rare tumors, accounting for only about 0.3% of all neoplasms. Most paragangliomas are defined as benign in nature, but 10-% possess metastatic potential. There have been scattered reports of metastatic paraganglioma in the literature, but in rare circumstances, paragangliomas can metastasize to the spinal column causing destruction or compression of the spinal cord, clinically manifesting as pain or neurological deficit.

CASE REPORT

We present a case of a 43-year-old man who presented with paresthesia and paraparesis and was found to have pathologic fracture involving D1 vertebra as a manifestation of metastasis from a non-secretory right paratesticular paraganglioma.

CONCLUSIONS

We will review the literature on the topic of metastatic paraganglioma, management of paragangliomas involving spine, and touch on the importance of angioembolization, staged procedures, and a team approach.

BK polyomavirus infection after renal transplantation: Surveillance in a resource-challenged setting

BACKGROUND

There is a paucity of data available about BK polyomavirus (BKPyV) infection after renal transplantation (RTX) in resource-limited countries with a predominantly living-donor, ABO-compatible RTX program. We aimed to assess BKPyV infection in such patients in a public hospital in India.

METHODS

We prospectively evaluated plasma BKPyV replication in 62 patients at 1, 3, 6, 9, and 12 months after RTX. Sustained significant BK viremia (SSBKV) was defined as significant viremia (≥10 000 copies/mL) detected ≥2 times, and BKPyV-associated nephropathy (BKVAN) as histologic changes of BKVAN with BK viremia with/without graft dysfunction.

RESULTS

All patients underwent RTX without requiring desensitization. Incidence of BK viremia was: 17.7%, 41.9%, 16.1%, 25.8%, and 17.7% at 1, 3, 6, 9, and 12 months, respectively. Of 62 patients, 64.5% had BKPyV viremia during the study, 32.2% had significant viremia, all except one detected in the first 6 months. Nine (14.5%) patients had SSBKV. There was no biopsy-proven BKVAN. At the end of 1 year, mean serum creatinine was higher and graft dysfunction was significantly more common in patients with SSBKV compared to those without SSBKV.

CONCLUSION

Transient BK viremia is common in low/intermediate immunologic risk RTX recipients in India, with a peak occurring at 3-6 months. Most clear their viremia by 12 months. Graft dysfunction seems to be more frequent in patients with SSBKV, although BKVAN is uncommon on biopsy in these patients.

Increased expression of platelet-derived growth factor associated protein-1 is associated with PDGF-B mediated glioma progression

The current treatment therapies available for malignant gliomas are inadequate. There is an urgent need to develop more effective therapies by characterizing the molecular pathogenesis of the disease. Over expression of platelet-derived growth factor (PDGF) ligands and receptors have been reported in malignant gliomas. Platelet-derived growth factor associated protein-1 (PDAP-1) is reported to modulate the mitogenic activity of PDGF ligands, but to date, there is no information concerning its role in PDGF-mediated glioma cell proliferation. This study aimed to characterize the role of PDAP-1 in PDGF-mediated glioma proliferation. The expression of PDAP-1 was observed to be significantly increased (p<0.05) in grade IV glioma tissue and cell lines compared to grade III. siRNA-mediated knockdown of PDAP-1 reduced the expression of PDGF-B and its downstream genes (Akt1/Protein kinase B (PKB) and phosphoinositide-dependent kinase-1 (PDK1) by up to 50%. In PDAP-1 knockdown glioma cells, more than a twofold reduction was also observed in the level of phosphorylated Akt. Interestingly, knockdown of PDAP-1 in combination with PDGF-B antibody inhibited glioma cell proliferation through activation of Caspase 3/7 and 9. We also demonstrate that PDAP-1 co-localizes with PDGF-B in the cytoplasm of glioma cells, and an interaction between both of the proteins was established. Collectively, these findings suggest that the expression of PDAP-1 is associated with disease malignancy, and its inhibition reduced the proliferation of malignant glioma cells through down-regulation of PDGF-B/Akt/PDK1 signaling. Thus, this study establishes PDAP-1 as an effecter of PDGF signaling in glioma cells and suggests that it could also be a promising therapeutic target.

Cysteinyl Leukotrienes (CysLTs): Role in Obesity-Induced Asthma

Epidemiological studies associate obesity with onset of asthma, especially in obese children, suggesting obesity as the risk factor for asthma. Obesity-induced chronic inflammation has been implicated in the lung inflammation, yet specific mediators and mechanisms are lacking. Obesity is associated with increased expression of 5-lipoxygenase (5-LO) pathway and increased Leukotrienes (LTs) production has been observed in obese asthma patients. However, the precise mechanism that predisposes lungs inflammation in obese is not clearly understood. This article discusses the production and regulation of LTs in obese individuals and presents probable mechanisms regarding the role of LTs in lung inflammation that may lead to obesity-induced asthma. Leukotrienes are well known mediators of asthma but their role in obesity-induced asthma is not clearly understood and thus needs further research. Since efficient antagonists and inhibitors of 5-LO pathways are known, understanding of molecular mechanism of LTs, especially Cysteinyl-LTs, in obesity-induced asthma could lead to optimal treatment regimens for the prevention and treatment of asthma in obese individuals.

Graphene/Nickel Nanofiber Hybrids for Catalytic and Microbial Fuel Cell Applications

The present work deals with the preparation of fcc-nickel (Ni) nanofibers and Graphene/Ni hybrids. The analysis of XRD, FTIR and Raman data confirms the formation of pure Ni, graphite oxide, reduced graphene and their hybrids. SEM micrographs clearly show the decoration of Ni nanofibers on the graphene flakes. The synthesized Ni-based hybrid systems can have applications in areas ranging from: magnetism, catalysis to microbial fuel cells. The vibrating sample magnetometer (VSM) investigations reveal that the hybrid structure shows hysteresis loop similar to that expected from a superparamagnetic system. When the same hybrid structure is used as catalyst for decolourization of 4-nitrophenol, the maximum rate constant of 0.1 min⁻¹ can be obtained. The catalytic activity also shows dependence on the loading concentration of Ni. The enhanced performance can be explained on the basis of synergistic effect between graphene and nickel nanofibers. The developed hybrids have also been applied as catalyst for cathode in microbial fuel cells and the studies showed improved power density compared to conventional microbial fuel cells (MFCs).

Infrared spectrum, NBO, HOMO-LUMO, MEP and molecular docking studies (2E)-3-(3-nitrophenyl)-1-[4-piperidin-1-yl]prop-2-en-1-one

FT-IR spectrum of (2E)-3-(3-nitrophenyl)-1-[4-piperidin-1-yl]prop-2-en-1-one was recorded and analyzed. The vibrational wavenumbers were computed using HF and DFT quantum chemical calculations. The data obtained from wavenumber calculations are used to assign IR bands. Potential energy distribution was done using GAR2PED software. The geometrical parameters of the title compound are in agreement with the XRD results. NBO analysis, HOMO-LUMO, first and second hyperpolarizability and molecular electrostatic potential results are also reported. The possible electrophile attacking sites of the title molecule is identified using MEP surface plot study. Molecular docking results predicted the anti-leishmanic activity for the compound.

Molecular structure, FT-IR, FT-Raman, NBO, HOMO and LUMO, MEP, NLO and molecular docking study of 2-[(E)-2-(2-bromophenyl)ethenyl]quinoline-6-carboxylic acid

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 2-[(E)-2-(2-bromophenyl)ethenyl]quinoline-6-carboxylic acid have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of the normal modes of vibrations was done using GAR2PED program. (1)H NMR chemical shifts calculations were carried out by using B3LYP functional with SDD basis set. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. MEP was performed by the DFT method and the predicted infrared intensities and Raman activities have also been reported. The calculated geometrical parameters are in agreement with that of similar derivatives. The title compound forms a stable complex with PknB as is evident from the binding affinity values and the molecular docking results suggest that the compound might exhibit inhibitory activity against PknB and this may result in development of new anti-tuberculostic agents.

FT-IR, HOMO-LUMO, NBO, MEP analysis and molecular docking study of 3-Methyl-4-{(E)-[4-(methylsulfanyl)-benzylidene]amino}1H-1,2,4-triazole-5(4H)-thione

FT-IR spectrum of 3-Methyl-4-{(E)-[4-(methylsulfanyl)-benzylidene]amino}1H-1,2,4-triazole-5(4H)-thione was recorded and analysed. The vibrational wavenumbers were computed and at HF and DFT levels of theory. The data obtained from wavenumber calculations are used to assign the vibrational bands obtained in the IR spectrum. The NH stretching wavenumber is red shifted in the IR spectrum from the computed value, which indicates the weakening of the NH bond. The geometrical parameters of the title compound are in agreement with the XRD results. NBO analysis, HOMO-LUMO, first and second order hyperpolarizability and molecular electrostatic potential results are also reported. From the MEP map it is evident that the negative regions are localized over the sulphur atoms and N3 atom of triazole ring and the maximum positive region is localized on NH group, indicating a possible site for nucleophilic attack. Prediction of Activity Spectra analysis of the title compound predicts anti-tuberculostic activity with probability to be active value of 0.543. Molecular docking studies reveal that the triazole nitrogen atoms and the thione sulphur atom play vital role in bonding and results draw us to the conclusion that the compound might exhibit anti-tuberculostic activity.

Molecular conformational analysis, vibrational spectra, NBO, NLO analysis and molecular docking study of bis[(E)-anthranyl-9-acrylic]anhydride based on density functional theory calculations

FT-IR and FT-Raman spectra of bis[(E)-anthranyl-9-acrylic]anhydride were recorded and analyzed. The conformational behavior is also investigated. The vibrational wave numbers were calculated using density functional theory (DFT) quantum chemical calculations. The data obtained from wave number calculations are used to assign vibrational bands obtained in Infrared and Raman spectra. Potential energy distribution was done using GAR2PED program. The geometrical parameters are compared with related structures. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using Natural Bonding Orbital (NBO) analysis. The Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) analysis are used to determine the charge transfer within the molecule. Molecular Electrostatic Potential (MEP) was performed by the DFT method. The calculated first hyperpolarizability of the title compound is comparable with the reported values of similar derivatives and is 4.23 times that of the standard nonlinear optical (NLO) material urea and the title compound and its derivatives are an attractive object for future studies of nonlinear optical properties. To evaluate the in silico antitumor activity of the title compound molecular docking studies were carried out against protein Bcl-xL. The (1)H-NMR spectrum is also reported.

Spectroscopic investigation (FT-IR, FT-Raman), HOMO-LUMO, NBO analysis and molecular docking study of 4-chlorophenyl quinoline-2-carboxylate

FT-IR and FT-Raman spectra of 4-chlorophenyl quinoline-2-carboxylate were recorded and analyzed. The vibrational wavenumbers were computed using DFT quantum chemical calculations. The data obtained from wavenumber calculations are used to assign vibrational bands obtained experimentally. Potential energy distribution was done using GAR2PED program. The geometrical parameters obtained theoretically are in agreement with the XRD data. NBO analysis, HOMO-LUMO, first hyperpolarizability and molecular electrostatic potential results are also reported. The calculated hyperpolarizability of the title compound is 77.53 times that of the standard NLO material urea and the title compound and its derivatives are attractive object for future studies of nonlinear optical properties. Molecular docking results suggest that the compound might exhibit inhibitory activity against GPb.

Cloning, expression, purification, crystallization and preliminary X-ray diffraction studies of NAD synthetase from methicillin-resistant Staphylococcus aureus

Staphylococcus aureus is an important human and animal pathogen that causes a wide range of infections. The prevalence of multidrug-resistant S. aureus strains in both hospital and community settings makes it imperative to characterize new drug targets to combat S. aureus infections. In this context, enzymes involved in NAD metabolism and synthesis are significant drug targets as NAD is a central player in several cellular processes. NAD synthetase catalyzes the last step in the biosynthesis of nicotinamide adenine dinucleotide, making it a crucial intermediate enzyme linked to the biosynthesis of several amino acids, purine and pyrimidine nucleotides, coenzymes and antibiotics.

Vibrational spectroscopic and molecular docking study of 4-Methylphenylquinoline-2-carboxylate

FT-IR and FT-Raman spectra of 4-Methylphenylquinoline-2-carboxylate were recorded and analyzed. The structure of the molecule has been optimized and structural characteristics have been determined by density functional theory. The geometrical parameters (DFT) are in agreement with the XRD results. HOMO and LUMO and other chemical properties are reported. Nonlinear optical properties are also reported. A detailed molecular picture of the title compound and its interactions were obtained from NBO analysis. The negative (red and yellow) regions of the MEP are related to electrophilic reactivity and the positive (blue) regions to nucleophilic reactivity, as shown in the MEP plot and the carbonyl group and the phenyl rings are observed as electrophilic. PASS analysis predicts that the 4-Methylphenylquinoline-2-carboxylate might exhibit anti-diabetic activity. Molecular docking results suggest that the compound might exhibit inhibitory activity against GPb.

Effect of grain size and microstructure on radiation stability of CeO2: an extensive study

To investigate the variation in the radiation stability of ceria with microstructure under the electronic excitation regime, ceria samples sintered under different conditions were irradiated with high energy 100 MeV Ag ions. The ceria nanopowders were synthesized and sintered at 800 °C (S800), 1000 °C (S1000) and 1300 °C (S1300), respectively. The samples with widely varying grain size, densities and microstructure were obtained. The pristine and irradiated samples were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). None of the samples amorphized up to the highest fluence of 1 × 10(14) ions per cm(2) employed in this study. XRD and Raman studies showed that the sample with lowest grain size suffered maximum damage while the sample with largest grain size was most stable and showed little change in crystallinity. Raman spectroscopy indicated the enhanced formation of Ce(3+) and related defects in the sample with larger grain size after irradiation. The most intriguing result was the absence of Ce(3+)-related defects in the sample with lowest grain size which actually showed maximum damage upon irradiation. The XPS studies on S800 and S1300 provided concrete evidence for the presence of Ce(3+) and oxygen ion vacancies in S1300. The grain boundaries and grain size dependent stability have been discussed.

Probing photo-carrier collection efficiencies of individual silicon nanowire diodes on a wafer substrate

Vertically aligned silicon nanowire (SiNW) diodes are promising candidates for the integration into various opto-electronic device concepts for e.g. sensing or solar energy conversion. Individual SiNW p-n diodes have intensively been studied, but to date an assessment of their device performance once integrated on a silicon substrate has not been made. We show that using a scanning electron microscope (SEM) equipped with a nano-manipulator and an optical fiber feed-through for tunable (wavelength, power using a tunable laser source) sample illumination, the dark and illuminated current-voltage (I-V) curve of individual SiNW diodes on the substrate wafer can be measured. Surprisingly, the I-V-curve of the serially coupled system composed of SiNW/wafers is accurately described by an equivalent circuit model of a single diode and diode parameters like series and shunting resistivity, diode ideality factor and photocurrent can be retrieved from a fit. We show that the photo-carrier collection efficiency (PCE) of the integrated diode illuminated with variable wavelength and intensity light directly gives insight into the quality of the device design at the nanoscale. We find that the PCE decreases for high light intensities and photocurrent densities, due to the fact that considerable amounts of photo-excited carriers generated within the substrate lead to a decrease in shunting resistivity of the SiNW diode and deteriorate its rectification. The PCE decreases systematically for smaller wavelengths of visible light, showing the possibility of monitoring the effectiveness of the SiNW device surface passivation using the shown measurement technique. The integrated device was pre-characterized using secondary ion mass spectrometry (SIMS), TCAD simulations and electron beam induced current (EBIC) measurements to validate the properties of the characterized material at the single SiNW diode level.

Fabrication of nanoadjuvant with poly-ε-caprolactone (PCL) for developing a single-shot vaccine providing prolonged immunity

Purpose

The aim of the study was to load a model antigen, tetanus toxoid (TT), in poly-ε-caprolactone nanoparticles (PCL NPs) of two size ranges, ie, mean 61.2 nm (small) and 467.6 nm (large), and study its effect on macrophage polarization as well as antigen presentation in human monocyte-derived macrophages in vitro, along with humoral and cell-mediated immune (CMI) response generated in Swiss albino mice following immunization with the TT-loaded NPs.

Materials and methods

PCL NPs were synthesized by solvent evaporation. The antigen-loaded PCL NPs were characterized for size, zeta potential, and protein-release kinetics. Swiss albino mice were immunized with the antigen-loaded PCL NPs. Flow cytometry was used to quantify interferon-γ- and interleukin-4-secreting cluster of differentiation (CD)4⁺ and CD8⁺ T cells in the spleen, and enzyme-linked immunosorbent assay was used to quantify anti-TT antibody levels in the serum of immunized mice.

Results

Small PCL NPs generated an M1/M2 type polarization of human blood monocyte-derived macrophages and T helper (Th)1/Th2 polarization of autologous CD4⁺ T cells. Efficient CD8⁺ T-cell responses were also elicited. Large PCL NPs failed to cause any type of macrophage polarization. They did not elicit efficient CD8⁺ T-cell responses.

Conclusion

TT-loaded small PCL NPs were able to generate persistent and strong CMI and humoral responses against TT 2 months after single injection in mice without booster dose. This biodegradable nanoadjuvant system may help to develop single-shot immunization for prolonged immunity without booster doses. The capability of enhanced CMI response may have high translational potential for immunization against intracellular infection.

QSAR guided semi-synthesis and in-vitro validation of anticancer activity in ursolic acid derivatives

As a part of our anticancer drug discovery programme, QSAR models were developed for the prediction of anticancer activities of ursolic acid derivatives against the human hepatocellular carcinoma HepG2, breast carcinoma MDA-MB-231 and the human ductal breast epithelial T47D cancer cell lines followed by wet lab semi-synthesis of virtually active derivatives, their in-vitro biological evaluation and apoptosis. The development of QSAR models was carried out by forward stepwise multiple linear regression method using a leave-one-out approach. Virtually active derivatives were semi synthesized, spectroscopically characterized and then in-vitro tested against human cancer cell lines. Active derivatives were checked via DNA fragmentation assay. The results exhibited regression coefficients (r(2)) and the cross-validation regression coefficients (rCV(2)) for the human HepG2, MDA-MB-231 and T47D cancer cell lines as .95 and .90; .92 and .87; .89 and .83 respectively showing the prediction accuracy of the models against biological activities. Computational molecular modeling is a valid modern approach, widely used in the identification of potential drug leads. The most active virtual derivatives of UA were semi- synthesized and their in-vitro and ex-vivo evaluation showed similar results with the predicted one, validating our QSAR models. Out of several active derivatives, the three UA2, UA7 and UA10 were potentially active against the above human cancer cell lines. These findings may be of immense importance in the anticancer drug development of an inexpensive and widely available natural product, ursolic acid.

Evaluation of internal target volume in patients undergoing image-guided intensity modulated adjuvant radiation for gastric cancers

OBJECTIVE

To evaluate three-dimensional (3D) displacements of gastric remnant during adjuvant radiation.

METHODS

From January 2011 to September 2012, patients undergoing adjuvant image-guided intensity-modulated radiation on tomotherapy were included. Megavoltage CT (MVCT) data sets from daily treatment were coregistered with Day 1 MVCT. Residual stomach remnant was delineated on the data set, while the remaining were blinded to previous day contours. Gastric volume and centre of mass (COM) were determined for all data sets. The 3D deviation of COM was calculated for each fraction. Mean 3D and standard deviation (SD) were calculated for each patient and study population, and a 95% confidence interval (CI) was determined. Also, systematic and random errors for patient population and internal target volume (ITV) margin were calculated using the van Herk formula.

RESULTS

There were 119 images available for 15 patients. Mean volume of remnant was 319 cm(3) (146-454 cm(3)). Gastric remnant expanded in different directions with no specific directional expansion. Average deviations in mediolateral, superoinferior and anteroposterior directions were 9 mm (3-25 mm; SD, 5 mm), 6 mm (3-16 mm; SD, 4 mm) and 5 mm (1-10 mm; SD, 3 mm), respectively, with 95% CI of 18, 15 and 11 mm, and ITV margins of 19.2, 13.5 and 7.8 mm, respectively.

CONCLUSION

There is large variation in gastric remnant volume during the course of radiation. Large displacements observed in the present study necessitate the need to investigate adaptive techniques for optimizing intensity-modulated radiotherapy (IMRT) delivery.

ADVANCES IN KNOWLEDGE

An adaptive strategy needs to be developed to optimize IMRT delivery for adjuvant gastric irradiation.

Transient receptor potential channel 6 (TRPC6) protects podocytes during complement-mediated glomerular disease

Gain-of-function mutations in the calcium channel TRPC6 lead to autosomal dominant focal segmental glomerulosclerosis and podocyte expression of TRPC6 is increased in some acquired human glomerular diseases, particularly in membranous nephropathy. These observations led to the hypothesis that TRPC6 overactivation is deleterious to podocytes through pathological calcium signaling, both in genetic and acquired diseases. Here, we show that the effects of TRPC6 on podocyte function are context-dependent. Overexpression of TRPC6 alone did not directly affect podocyte morphology and cytoskeletal structure. Unexpectedly, however, overexpression of TRPC6 protected podocytes from complement-mediated injury, whereas genetic or pharmacological TRPC6 inactivation increased podocyte susceptibility to complement. Mechanistically, this effect was mediated by Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) activation. Podocyte-specific TRPC6 transgenic mice showed stronger CaMKII activation, reduced podocyte foot process effacement and reduced levels of proteinuria during nephrotoxic serum nephritis, whereas TRPC6 null mice exhibited reduced CaMKII activation and higher levels of proteinuria compared with wild type littermates. Human membranous nephropathy biopsy samples showed podocyte staining for active CaMKII, which correlated with the degree of TRPC6 expression. Together, these data suggest a dual and context dependent role of TRPC6 in podocytes where acute activation protects from complement-mediated damage, but chronic overactivation leads to focal segmental glomerulosclerosis.