Synergistic reduction of nitrophenols by Au-CDs nanoconjugates with NaBH4.

Developing sustainable and innovative approaches for the efficient reduction of nitrophenols is crucial for environmental remediation, for managing health concerns posed by their widespread presence as hazardous pollutants in industrial effluents and contaminated water. We report the use of 12.9 ± 1 nm (TEM data) sized gold carbon dot nanoconjugates (Au@CDs) for catalytic conversion of o, m, p-nitrophenols to aminophenols by sodium borohydride. A simple approach was followed to synthesize ultra-small and highly stable Au@CDs, using citric acid and PEG as reducing and stabilizing agents. X-ray diffraction analysis verified the formation of nano-crystalline nanoconjugates. These nanoconjugates showed a remarkable catalytic activity in the range of 0.22-0.33 s-1(varying with nanoconjugate concentration) which was much higher compared to conventional chemical methods of reduction. All the catalytic reaction experiments were performed at room temperature (27 ± 2 °C). Furthermore, an increase in rate constant was observed with increasing concentration of nanoconjugates. The catalytic activity of Au@CDs nanoconjugates was observed to be in order of m-nitrophenol > o-nitrophenol > p-nitrophenol with apparent rate constant (kaap) values of 0.068, 0.043 and 0.031, respectively. Comparative analysis with GNPs, CDs and Au@CDs nanoconjugates stated that the nanoconjugates had superior catalytic activity. The research can have significant implications in the development of new strategies for environmental remediation and biomedical applications.

Fusarium wilt pandemic: current understanding and molecular perspectives.

Plant diseases pose a severe threat to the food security of the global human population. One such disease is Fusarium wilt, which affects many plant species and causes up to 100% yield losses. Fusarium pathogen has high variability in its genetic constitution; therefore, it has evolved into different physiological races to infect different plant species spread across the different geographical regions of the world. The pathogen mainly affects plant roots, leading to colonizing and blocking vascular bundle cells, specifically xylem vessels. This blocking results in chlorosis, vascular discoloration, leaf wilting, shortening of plant, and, in severe cases, premature plant death. Due to the soil-borne nature of the wilt pathogen, neither agronomic nor plant protection measures effectively reduce the incidence of the disease. Therefore, the most cost-effective management strategy for Fusarium wilt is developing varieties resistant to a particular race of the fungus wilt prevalent in a given region. This strategy requires understanding the pathogen, its disease cycle, and epidemiology with climate-changing scenarios. Hence, in the review, we will discuss the pathogenic aspect and genetics of the Fusarium wilt, including molecular interventions for developing climate-smart wilt tolerant/resistant varieties of crops. Overall, this review will add to our knowledge for advancing the breeding of resistance against the wilt pandemic.

Regulation of NLGN3 and the Synaptic Rho-GEF Signaling Pathway by CDK5.

Neuroligins (NLGNs) are postsynaptic cell adhesion molecules that are involved in synapse assembly and function. The NLGN gene family consists of 5 genes (NLGN1-3, 4X, and 4Y). NLGN3 forms heterodimers with other NLGNs and is expressed at both excitatory and inhibitory synapses, although the distinct role at different synapses is not fully understood. Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase that targets various neuronal substrates to impact neuronal migration, neurite outgrowth, synaptic transmission, and plasticity. Both NLGNs and their presynaptic binding partners neurexins are highly associated with neurodevelopmental disorders. The NLGN3 gene is on the X chromosome and variants in NLGN3 have been linked to the pathophysiology in neurodevelopmental disorders. To better understand the endogenous modulation of NLGN3, we generated an HA-tagged knock-in mouse. We found that Cdk5 associates with NLGN3 in vivo and phosphorylates NLGN3 on serine 725 (S725) in the knock-in mouse of either sex. The phosphorylation affects the NLGN3 association with Kalirin-7, a postsynaptic guanine nucleotide exchange factors for Rho GTPase family proteins. We further observed that the phosphorylation modulates NLGN3 surface expression and NLGN3-mediated synaptic currents in cultured rat neurons. Thus, we characterized NLGN3 as a novel Cdk5 substrate and revealed the functional consequences of NLGN3 S725 phosphorylation in neurons. Our study provides a novel molecular mechanism underlying Cdk5-mediated regulation of postsynaptic cell adhesion molecules.SIGNIFICANCE STATEMENT NLGN3 is involved in synapse assembly and function at both excitatory and inhibitory synapses and has been associated with the pathophysiology of neurodevelopmental disorders. Cdk5 has brain-specific activity and is involved in neuronal transmission, synapse function, and plasticity. Here, we characterize NLGN3 as a Cdk5 substrate for the first time and show that Cdk5-mediated phosphorylation regulates NLGN3 function. We demonstrate that NLGN3 S725 is a Cdk5 phosphorylation site, and reveal that the site is important for NLGN3 association with Kalirin-7, NLGN3 surface expression, and NLGN3-mediated synaptic transmission.

Drought stress in maize: stress perception to molecular response and strategies for its improvement.

Given the future demand for food crops, increasing crop productivity in drought-prone rainfed areas has become essential. Drought-tolerant varieties are warranted to solve this problem in major crops, with drought tolerance as a high-priority trait for future research. Maize is one such crop affected by drought stress, which limits production, resulting in substantial economic losses. It became a more serious issue due to global climate change. The most drought sensitive among all stages of maize is the reproductive stages and the most important for overall maize production. The exact molecular basis of reproductive drought sensitivity remains unclear due to genes' complex regulation of drought stress. Understanding the molecular biology and signaling of the unexplored area of reproductive drought tolerance will provide an opportunity to develop climate-smart drought-tolerant next-generation maize cultivars. In recent decades, significant progress has been made in maize to understand the drought tolerance mechanism. However, improving maize drought tolerance through breeding is ineffective due to the complex nature and multigenic control of drought traits. With the help of advanced breeding techniques, molecular genetics, and a precision genome editing approach like CRISPR-Cas, candidate genes for drought-tolerant maize can be identified and targeted. This review summarizes the effects of drought stress on each growth stage of maize, potential genes, and transcription factors that determine drought tolerance. In addition, we discussed drought stress sensing, its molecular mechanisms, different approaches to developing drought-resistant maize varieties, and how molecular breeding and genome editing will help with the current unpredictable climate change.

Guided mode resonance immunosensor for label-free detection of pathogenic bacteria Pseudomonas aeruginosa.

Photonic biosensors are promising platforms for the rapid detection of pathogens with the potential to replace conventional diagnostics based on microbiological culturing methods. Intricately designed sensing elements with robust architectures can offer highly sensitive detection at minimal development cost enabling rapid adoption in low-resource settings. In this work, an optical detection scheme is developed by structuring guided mode resonance (GMR) on a highly stable, transparent silicon nitride (SiN) substrate and further biofunctionalized to identify a specific bacteria Pseudomonas aeruginosa. The resonance condition of the GMR chip is optimized to have relatively high bulk sensitivity with a good quality factor. The biofunctionalization aims at oriented immobilization of specific antibodies to allow maximum bacteria attachment and improved specificity. The sensitivity of the assays is evaluated for clinically relevant concentrations ranging from 102 to 108 CFU/mL. From the calibration curves, the sensitivity of the chip is extracted as 0.134nm/Log10 [concentration], and the detection modality possesses a favorably good limit of detection (LOD) 89 CFU/mL. The use of antibodies as a biorecognition element complemented with a good figure of merit of GMR sensing element allows selective bacteria identification compared to other non-specific pathogenic bacteria that are relevant for testing physiological samples. Our developed GMR biosensor is low-cost, easy to handle, and readily transformable into a portable handheld detection modality for remote usage.

Biocompatible gelatin/carbon dot nanocomposite based urea sensor and the effect of nitrogen ion implantation.

In this study, we have fabricated a novel platform for sensing of urea using gelatin/carbon dots nanocomposite system. The sensor electrode was created by depositing the nanocomposite gel onto thin glass plates coated with indium tin oxide (ITO) using the drop casting technique. The behavior of these electrodes was investigated against a number of bioanalytes in the concentration range of 2-20 mM by cyclic voltammetry. The system was observed to be highly selective for urea with a sensitivity of 1.65 µA/mM/cm in the experimental linear range of 2-20 mM. Furthermore, the gelatin/CD-ITO electrode were also subjected to 50 KeV N2+ ion beam irradiation with varying fluence in the range of 1012 to 1016 ions/cm2. Sensing profile of the irradiated samples for urea suggested enhancement in sensitivity to 2 µA/mM cm2, when the ion fluence was 5 × 1015 ions/cm2. This enhancement after irradiation suggests a clear dependence of detection on the fluence of the ion beam. The observed excellent sensitivity of radiation processed nanocomposite material can be used as an enzyme-free platform for urea detection. Additionally, the CDs showed fluorescence quenching on treatment with mere 50 µM urea suggesting the high sensitivity of the platform.

Reduced graphene Oxide/NiO based nano-composites for the efficient removal of alizarin dye, indigo dye and reduction of nitro aromatic compounds.

Removal of alizarin red S (ARS) and Indigo dye from aqueous media and reduction of nitro aromatic compounds are successfully done under mild condition by using reduced Graphene Oxide-Nickel Oxide (rGO-NiO) nanocomposite as catalyst. RGO-NiO is well characterized by different analytical techniques. Morphology, structural, and composition studies done by HRTEM, FESEM, EDX, TGA, FTIR, XPS, Raman spectroscopy, and XRD. RGO-NiO nanocomposite has high stability for the removal of ARS, Indigo dye, reduction reaction nitro aromatic compounds.

Identification of novel inhibitors for trigger factor (TF) of M. tb: an in silico investigation.

Trigger factor, as a chaperone protein, is required for survival of Mycobacterium tuberculosis (M.tb) in a stressed environment. This protein interacts with various partners in both the pre- and the post-translation processes, yet the crystal structures of the M.tb trigger factor remain unresolved. In this study, we developed a homology model of M.tb trigger factor to facilitate the discovery and design of inhibitors. To validate the model, we employed several methodologies, including Ramachandran plot and molecular dynamics simulations. The simulations showed a stable trajectory, indicating the accuracy of the model. The active site of M.tb Trigger Factor was identified based on site scores, and virtual screening of over 70,000 compounds led to the identification of two potential hits: HTS02984 (ethyl 2-(3-(4-fluorophenyl)ureido)-6-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate) and S06856 ((E)-N-(4-((2-(4-(tert-butyl)benzoyl)hydrazono)methyl)phenyl) acetamide). These compounds showed strong binding affinity and energy scores, and their chemical descriptors were evaluated. Our study provides a reliable computational model for M.tb Trigger Factor and identifies two potential inhibitors for this crucial protein, which could aid in the development of novel therapies against tuberculosis.Communicated by Ramaswamy H. Sarma.

The potentialities of omics resources for millet improvement.

Millets are nutrient-rich (nutri-rich) cereals with climate resilience attributes. However, its full productive potential is not realized due to the lack of a focused yield improvement approach, as evidenced by the available literature. Also, the lack of well-characterized genomic resources significantly limits millet improvement. But the recent availability of genomic data and advancement in omics tools has shown its enormous potential to enhance the efficiency and precision faced by conventional breeding in millet improvement. The development of high throughput genotyping platforms based on next-generation sequencing (NGS) has provided a low-cost method for genomic information, specifically for neglected nutri-rich cereals with the availability of a limited number of reference genome sequences. NGS has created new avenues for millet biotechnological interventions such as mutation-based study, GWAS, GS, and other omics technologies. The simultaneous discovery of high-throughput markers and multiplexed genotyping platform has aggressively aided marker-assisted breeding for millet improvement. Therefore, omics technology offers excellent opportunities to explore and combine useful variations for targeted traits that could impart high nutritional value to high-yielding cultivars under changing climatic conditions. In millet improvement, an in-depth account of NGS, integrating genomics data with different biotechnology tools, is reviewed in this context.

Reinfection of COVID-19 among doctors at a tertiary care centre in Northern India: A report from a resource-limited setting.

Background and Aims: There is an increasing recognition of reinfection in coronavirus disease 2019 (COVID-19). We studied the reinfection of COVID-19 disease among doctors at a tertiary care centre in Northern India. Methods: All COVID-19 patients readmitted for COVID-19 disease after any duration with at least a positive Real time- polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome coronavirus 2 were included. Their clinical profile, vaccination status, outcome and Centre for disease control (CDC), Atlanta, USA reinfection criteria screening were recorded. Results: A total of 57 (0.53%) doctors were identified and 56 of them satisfied the CDC criteria. It included 13 (20.3%) females and 89.3% of cases were from clinical specialities; 98.2% of individuals had the first infection in 2020 and mean duration between 2 infections was 156.29 ± 76.02 (35-298) days. Duration between two episodes of the disease with more than 90 days apart was in 80.3% cases. One (1.8%) patient developed severe disease and two (3.6%) cases were of moderate severity. Symptoms were similar in both infections except significantly higher number of extra-respiratory complaints (2.2% vs. 9.1%). There were 37.5% cases who had received first dose of vaccination of any duration at the time of second infection. Nine (16.1%) and four (7.1%) patients with more than 4 weeks after the first and second dose of vaccination developed the second infection, respectively. Conclusion: Majority of reinfection were symptomatic and developed after 90 days and so majority followed CDC criteria. Breakthrough infections among vaccinated healthcare worker are real, and with sustained exposure to the virus, they should continue to use precaution including hand hygiene and mask in order to prevent reinfection.

Gold-carbon dot (Au@Cd) nanoconjugates based electrochemical sensing of cholesterol and effect of nitrogen ion implantation on sensitivity.

Serum cholesterol dysregulation is associated with prognosis and diagnosis of many diseases and effective biosensor will improvise their management. A novel electrochemical biosensor was fabricated based on gelatin-Au@CD nanoconjugate films for cholesterol detection. Initially, the surface of indium titanium oxide (ITO) coated glass was modified by drop casting of gelatin-Au@CD nanoconjugates to prepare the electrodes. Electrochemical studies for detection of bioanalytes(such as urea (U), ascorbic acid (AA), oxalic acid (OA), gallic acid (GA), cholesterol (Chox), dextrose (D), l-cysteine (Cys) and citric acid (CA)) were performed using cyclic voltammetry. The presence of nanoconjugates provided an appropriate environment for enhanced electrochemical response for cholesterol. These electrodes exhibited a linear response towards the presence of cholesterol in the linear concentration range of 2-20 mM with a correlation coefficient of 0.95, and the superior sensitivity of 1.36 µA/mM/cm2. Additionally, enhanced sensitivity (2.99 µA/mM/cm2) of nitrogen ion irradiated films up to a fluence of 1016 ions/cm2 was noticed because of morphological changes in the electrode surface brought about by irradiation. Approximately 54% enhancement was found when the ion fluence was 1016 ions/cm2. The designed nanoconjugate electrode showed excellent response towards cholesterol sensing and eliminates the requirement of any enzymes making the overall process simpler, cost-effective and allows for room temperature storage.

Quantification of levetiracetam in plasma and urine and its application to a pharmacokinetic study of traumatic brain injury patients.

Background: Levetiracetam is an antiepileptic drug used to prevent or treat seizure in patients with severe traumatic brain injury. This study aimed to develop and validate methodology suitable for measuring levetiracetam concentrations in human plasma and urine. Methods: Plasma or urine (10 µl) samples were spiked with [2H6]-levetiracetam and processed using an acetonitrile precipitation. ESI-LC-MS/MS was employed for analyte detection. Results: The levetiracetam calibration was linear from 0.1 to 50 mg/l in a combined matrix of plasma and urine. Intra- and inter-assay imprecision and accuracy in plasma were <7.7 and 109%, and in urine were <7.9 and 108%, respectively. Conclusion: The validated method was applied to a pharmacokinetic study of levetiracetam in critically ill patients with severe traumatic brain injury.

Levetiracetam is a drug that is used for the prevention or treatment of seizure. This study aimed to design a method that would be suitable for measuring levetiracetam in human plasma and urine. The method was subsequently applied to a clinical study of patients with severe traumatic brain injury.

On the rise of fear speech in online social media.

Recently, social media platforms are heavily moderated to prevent the spread of online hate speech, which is usually fertile in toxic words and is directed toward an individual or a community. Owing to such heavy moderation, newer and more subtle techniques are being deployed. One of the most striking among these is fear speech. Fear speech, as the name suggests, attempts to incite fear about a target community. Although subtle, it might be highly effective, often pushing communities toward a physical conflict. Therefore, understanding their prevalence in social media is of paramount importance. This article presents a large-scale study to understand the prevalence of 400K fear speech and over 700K hate speech posts collected from Gab.com. Remarkably, users posting a large number of fear speech accrue more followers and occupy more central positions in social networks than users posting a large number of hate speech. They can also reach out to benign users more effectively than hate speech users through replies, reposts, and mentions. This connects to the fact that, unlike hate speech, fear speech has almost zero toxic content, making it look plausible. Moreover, while fear speech topics mostly portray a community as a perpetrator using a (fake) chain of argumentation, hate speech topics hurl direct multitarget insults, thus pointing to why general users could be more gullible to fear speech. Our findings transcend even to other platforms (Twitter and Facebook) and thus necessitate using sophisticated moderation policies and mass awareness to combat fear speech.

Acute necrotising encephalopathy: A rare complication providing a clue for the outbreak of H1N1 among medical students in Kanpur, India.

Kanpur, India, recently witnessed an outbreak of undifferentiated febrile illness among medical students. Several students developed high-grade fever with altered sensorium within 2-3 days after the index case. Surprisingly, this outbreak coincided with the death of several pigs in the vicinity. Acute necrotising encephalitis, although rare, was noted in some patients. When correlated with each other, all of these incidents were suggestive of an outbreak of H1N1.

Erratum to "Imaging diagnosis of a giant choledochal cyst in an infant" [Radiology Case Reports 17 (2022) 404-411].

[This corrects the article DOI: 10.1016/j.radcr.2021.10.051.].

Outcome of Adult Malarial Co-infections in Eastern India.

Introduction: Co-infection with different agents such as bacterial, viral, and Rickettsia is being increasingly recognized due to greater availability and utilization of the diagnostic tests among malaria patients. Methods: Consecutive admitted malarial cases were included and were subjected to test for general investigations, bacteria, typhoid, dengue, chikungunya, and rest for specific diagnosis. All patients were followed up till discharge or death and appropriate statistical tests were performed. Results: A total of 152 malaria patients were recruited and 27 (18.8%) had concurrent infections. It included 40.7% dengue only, 18.7% pneumonia, 11.1% urinary tract infection (UTI), 7.4% enteric fever, 3.7% leptospirosis, chikungunya, and tuberculous meningitis each, and 3.7% each of dengue with pneumonia and UTI. The organisms isolated were Streptococcus pneumoniae, Klebsiella pneumoniae, Escherichia coli, Salmonella typhi, and Mycobacterium tuberculosis. The mean duration of fever was 6.33 ± 3.63 days with a range of 3-20 days. Blood culture grew in 2 cases S. typhi and K. pneumonia,e. Dengue co-infections had significantly higher clinical and laboratory features of dengue and complications such as bleeding, jaundice, and cholecystitis, whereas rest concurrent infections had a significantly higher proportion of nausea and vomiting, convulsion, altered sensorium, productive cough, urinary symptoms, shock, acute kidney injury, anemia, and mean neutrophil count. There was significantly higher mortality among malaria-dengue concurrent infection group with 2 (15.4%) than malaria mono-infection group 3 (2.4%). Conclusion: Co-infections with malaria are not uncommon, especially dengue fever and other bacterial infections. The dominant clinical picture is of the superimposed infection. Decision should be clinically guided adjunct with specific diagnostic tests, and timely treatment has favorable outcome.

Fibronectin containing alternatively spliced extra domain A interacts at the central and c-terminal domain of Toll-like receptor-4.

Extra domain A of cellular fibronectin (FN-EDA) is known to cause insulin resistance, atherosclerosis, tissue fibrosis, ischemic stroke and exaggerated myocardial reperfusion injury through Toll-like receptor 4 (TLR4). However, the FN-EDA-TLR4 interacting site is not well established. Therefore, in-silico approaches have been used to study FN-EDA and TLR4 interactions at the interface. In the present study, molecular docking studies of FN-EDA with TLR4-myeloid differentiation factor 2 (MD2) heterodimer have been performed to unravel the FN-EDA-TLR4 interacting sequence. Furthermore, the modulatory role of FN-EDA adjacent domains FNIII(11) and FNIII(12) on its interaction with TLR4-MD2 was investigated. The results show that FN-EDA interacting sequence "SPEDGIRELF" selectively interacts with TLR4 directly near its central and C-terminal domain region. The regulatory domains, FN type III 11 facilitate and 12 impede the FN-EDA-TLR4 interaction. Furthermore, the molecular dynamic simulation studies confirmed that FN-EDA forms a stable complex with TLR4-MD2 heterodimer. In conclusion, FN-EDA interacts and forms a stable complex through its "SPEDGIRELF" sequence at the central and C-terminal domain region of TLR4. The revelation of FN-EDA and TLR4 interacting sites may help design novel therapeutics for drug discovery research.