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Four new water-soluble bidentate ligands, namely, (cyclopentadienyl)ethyl-1,3,5-triaza-7-phosphadamantane (1), 1,2-bis-(1,3,5-triaza-7-phosphaadamantan-6-yl) ethane (2), 1,3-bis-(1,3,5-triaza-7-phosphaaadamantan-6-yl) propane (3) and 1,4-bis-(1,3,5-triaza-7-phosphaadamantan-6-yl) butane (4) have been synthesized and characterized by multi-nuclear NMR (1H, 13C and 31P), elemental analysis and mass spectrometry. Compound 1 was synthesized by using two different synthetic routes in excellent yields and is also the first example of water-soluble chelating cyclopentadienyl ligand containing 1,3,5-triaza-7-phosphaadamantane. [ABSTRACT FROM AUTHOR]

Ruthenium-catalyzed formation of lactones from diols in aqueous medium has been demonstrated. 1,3,5-Triazaphosphaadamantane (PTA) included water-soluble ruthenium complexes [RuCl2 (PPh3)(2,6-Py-(CH2-PTA)2 ]·2Br and [RuCl2 (PPh3)2 (2-PyCH2 PTA)]·Br in the presence of KOH were found to be efficient for the synthesis of lactones from diols. The reported synthetic protocol is green as it uses water as solvent, avoids the use of any hydrogen acceptor/oxidant, and produces hydrogen as the only side product. Mechanistic studies revealed that lactone formation involved aldehyde intermediate and followed dehydrogenative pathway. [ABSTRACT FROM AUTHOR]

The synthesis of a ruthenium complex bearing a PN-chelating ligand is described. The complex, in the presence of KOH, enabled the synthesis of ketones from secondary alcohols in the absence of a hydrogen acceptor in aqueous medium. This synthetic protocol, which uses water as the medium, is green and has a high atom economy as it avoids the use of an acceptor and produces hydrogen as the sole byproduct. Mechanistic investigations revealed that the catalytic cycle involves a phosphine dissociative pathway. [ABSTRACT FROM AUTHOR]

An improvement of solid-state fluorescence from a luminous nanocomposite made from corn-starch-based bioplastic by adding intentionally Cu-doped carbon quantum dots (CQDs) has been reported. An affordable, environmentally sustainable, one-step hydrothermal technique was employed to synthesize CQDs from Brassica juncea flower extract. The morphological, structural, and physicochemical characteristics of the material were investigated. The quasi-circular shaped CQDs have been found to have a size distribution of 2–5 nm, to have yellow-greenish fluorescence upon UV stimulation, to have excellent photostability, and to be highly water soluble, with a quantum yield of up to 18.4%. Interestingly, the fluorescence spectra of intentionally Cu-doped CQDs (hereafter N, Ca, Cu-doped CQDs) were found to be brighter after 280 nm illumination than unintentional one. Furthermore, as a solid-phase dispersion matrix of CQDs, the environmentally benign and biodegradable bioplastic is appealing. As a result, this work demonstrated the effect of Cu-doping on solid-state fluorescence in the down-conversion of UVC tubes via a composite constructed by inserting CQDs into the solid-state matrix of corn-starch-based bioplastic nanocomposite, which demonstrated vivid greenish-yellow emission in the electroluminescent spectra with CIE chromatic coordinates (0.33, 0.58 vs. 0.31, 0.67). [ABSTRACT FROM AUTHOR]

Examines the role of voluntary exercise in changes in the energy balance during pregnancy of Syrian hamsters. Experimental manipulations of ovarian hormone levels; Level of food intake; Premating level of running wheel activity.

• A new Schiff base ligand N1, N5-bis[2-hydroxyphenyl]−2-methyl-1,5-diaminopentane is synthesized and characterized. • In-Silico studies of compounds to support the in-vitro results. • The increase in the spacer group in Schiff base compounds increases the biological activities. A novel ONNO donor tetradentate Schiff base ligand N,N' -bis[2- hydroxyphenyl]-2-methyl-1,5-diaminopentane (1) is synthesized and characterized by using 1H, 13C NMR spectroscopy and mass spectrometry. Biological studies on newly synthesized ligand are carried out and results are compared with the biological activities of known Schiff base ligands: N,N' -bis[{2- hydroxyphenyl }]-1,4-diaminobutane (2) and N,N' -bis[{2- hydroxyphenyl }]-1,3-diaminopropane (3). This comparative study highlights the effect of increasing methylene linkage on the biological activity of these ligands. The anti-microbial activities of all three ligands have been screened against two distinct gram-positive and gram-negative bacteria. In-vitro results of this comparative analysis are also supported by comprehensive molecular docking studies with DNA gyrase subunit B protein of gram-positive bacterium S. aureus and FabH–CoA complex of gram-negative bacterium E. coli. Experimental studies reveal that the spacer group plays a vital role in controlling the biological activities of the ligand. These findings are in good agreement with the theoretical findings. The study demonstrates that the biological activity of ligands is enhanced with increments in the number of spacers. Thus, the newly synthesized ligand (1) with the most extended spacer among the three showed the highest biological activity compared to other two ligands, similar to the popular drug Ciprofloxacin. [Display omitted] [ABSTRACT FROM AUTHOR]

• Solid-state fluorescence from Zn-doped CQDs@bioplastics nanocomposite is reported. • Zn-doped CQDs were synthesized from Brassicca juncea flower extract. • UVC-tube down-conversion was demonstrated with bioplastic nanocomposite. • Zn-doped bioplastic nanocomposite emits more brightly than the unintentional one. • CIE chromatic coordinates of (0.39, 0.56 vs. 0.29, 0.55) were obtained. The enhancement of solid-state fluorescence from nanocomposite bioplastics containing intentionally Zn-doped carbon quantum dots (CQDs) has been reported. For the synthesis of CQDs from Brassica juncea flower extract, an economical, ecologically sustainable, and one-step hydrothermal method was used. The morphological, structural, and physicochemical properties were examined. The quasi-circular shaped CQDs, with an average diameter of 4.7 nm, were discovered to emit yellow-greenish fluorescence upon UV stimulation, to have exceptional photostability, and to be highly water soluble, with a quantum yield of up to 18%. Furthermore, a commercial UVC-tube wrapped with bioplastic nanocomposite emitted a greenish-yellow colour where intentionally Zn-doped CQDs@bioplastic nanocomposite emits more intensely than an unintentional one with CIE chromatic coordinates (0.39, 0.56 vs. 0.29, 0.55). [ABSTRACT FROM AUTHOR]

Carbon quantum dots (CQDs)-based composite as a luminescent down-conversion materials are gaining importance nowadays because of many favorable factors including stable fluorescence, ease of functionalization, tuning of emission in visible range etc. In this work, we report an economical, sustainable and green synthesis of CQDs derived from mustard (Brassica juncea) flower extract. The as-synthesized CQDs were unintentionally doped with nitrogen and calcium without the inclusion of any doping element precursors. However, phosphorus was intentionally doped to improve the luminescent characteristics of as-synthesized CQDs. The morphological, structural, and physicochemical properties of P-doped CQDs were examined. The quasi-circular or polygonal-shaped CQDs, with an average diameter of 3.4 nm, emerged to produce yellow-greenish fluorescence upon UV stimulation, demonstrate outstanding photostability, and had a quantum yield of up to 18.2%. Furthermore, the ecologically friendly and biodegradable bioplastic is attractive as a solid phase dispersion matrix of CQDs. Hence, this work revealed the effect of phosphorus doping on solid-state fluorescence in the down-conversion of LEDs and UV tubes by producing a composite constructed through inserting CQDs into the solid-state matrix of corn-starch-based bioplastic. [Display omitted] • Effect of intentional P-doped in N,Ca-doped CQDs@bioplastic composite is reported. • Intentional P-doped CQDs were synthesized from Brassica juncea flower extract. • Down-conversion of LEDs and UV tubes have been demonstrated. • Influence of pH on fluorescence properties have also been investigated. [ABSTRACT FROM AUTHOR]

Biocompatibility, low toxicity, ease of functionalization, ecologically sustainable synthesis, and a diverse variety of applications have all contributed to the current popularity of fluorescent carbon quantum dots (CQDs), a relatively new rising star among zero-dimensional carbon nanomaterials. However, expensive precursors and production, as well as a time-consuming procedure, frequently restrict the economic design that must be addressed. In this work, we report an economical, sustainable and green synthesis of fluorescent CQDs co-doped with N and Ca from mustard (Brassica) flower extract without the need of additional doping element precursors. The quasi-circular or polygonal shaped CQDs were revealed to be yellow-greenish fluorescent in nature with outstanding photo-stability and excellent water solubility, with an average diameter of 4.38 nm and a relative quantum yield of about 15%. The compositional analysis, crystallinity, and functional groups contained in as-synthesized N,Ca-co-doped CQDs were determined by XPS, XRD, and FTIR analysis, respectively. The presence of dominant sp3 hybridized carbons over sp2 was confirmed by 1H NMR and 13C NMR spectroscopy. The plausible fluorescence mechanisms are also proposed. Additionally, a biodegradable bioplastic derived from corn starch was used to develop an N, Ca-co-doped CQDs@bioplastic composite in order to demonstrate how it may be used to produce down-conversion light emitting diodes and optical displays. The impact of CQD concentrations and pH sensitivity were investigated further. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • We report a simple, cost-effective, eco-sustainable synthesis of fluorescent carbon quantum dots derived from precursor Cissus quadrangularis. • The as-synthesized nitrogen doped-CQDs demonstrated a homogeneous size distribution (4–9 nm), green fluorescent nature, great photo-stability, excellent water solubility, and a quantum yield of around 5 %. • A biodegradable wheat-starch-based bioplastic was employed to fabricate an N-doped CQDs@bioplastic composite to demonstrate its potential applications in quantum dot-based optical displays and down-conversion light emitting diodes. • The influence of different CQD concentrations and pH sensitivity were investigated further utilizing fabricated optical displays and LEDs. Carbon quantum dots (CQDs)-based composites as luminous down-conversion materials are becoming more popular due to several advantages such as steady fluorescence, ease of functionalization, tailoring of emission in the visible range, and so on. We report an inexpensive and environmentally sustainable synthesis of fluorescent nitrogen doped-CQDs produced from Cissus quadrangularis , a low-cost plant precursor with therapeutic value. The morphological, structural, and physicochemical features of the material were carefully investigated. Under UV stimulation (365 nm), almost spherical shaped N-CQDs with an average diameter of 5.1 nm were discovered to generate yellow-green fluorescence, have excellent photostability, and strong water solubility, with a quantum yield of up to 5 %. Furthermore, as a solid-phase dispersion matrix for CQDs, ecologically friendly and biodegradable bioplastic is appealing. The down-conversion of solid-state fluorescence of LEDs and UVC tubes was demonstrated by creating a nanocomposite by inserting N-CQDs into the solid matrix of a wheat starch-based bioplastic. Furthermore, employing constructed quantum dot-based optical displays, down-converted LEDs, and UVC tubes, the impacts of varied CQD concentrations and pH sensitivity were examined. [ABSTRACT FROM AUTHOR]

Thermally activated perlite‐supported cobalt oxide (Co‐TAP) catalyst has been synthesized via the deposition‐precipitation method. FTIR peaks at around 663 and 565 cm–1 and XRD peaks arise from diffraction of FCC planes of CoO crystals confirm the presence of Co3O4 crystallites on Co‐TAP surface. UV–Vis DRS studies reveal the presence of octahedrally coordinated Co3+ and tetrahedrally coordinated Co2+ ions. EDX analysis of Co‐TAP clearly shows the enhanced percentage of silica and cobalt oxide. All characterization studies suggest the presence of Lewis acidic sites on Co‐TAP which have been utilized in a series of liquid‐phase esterification reactions of benzoic acid with various alcohols over three different reaction media (conventional, microwave, and sonication). The reactions are carried out in one‐pot, single‐step, solvent‐free reaction conditions, and the catalyst is filtered easily, regenerated, and reused up to five reaction cycles with analogous efficiency suggesting that acidic sites of the catalyst remain stable in all reaction mediums. The stability of regenerated Co‐TAP catalyst after the fifth reaction cycle is confirmed by FTIR spectrum which resembles the FTIR of fresh catalyst. [ABSTRACT FROM AUTHOR]

Introduction: The Coronavirus Disease 2019 (COVID-19) is associated with damage of cells of both innate and adaptive immunity, which results in immune system's impairment leading to secondary infections. Microbiological evaluation helps in diagnostic as well as antimicrobial stewardship leading to accurate treatment of COVID-19 infected patients. Aim: To evaluate superadded bacterial and fungal infections in COVID-19 infected patients and to evaluate bacterial and fungal infections in COVID-19 non infected patients admitted with Acute Respiratory Illness (ARI). Materials and Methods: This retrospective study was carried out in a tertiary care hospital in Delhi, India, over a period of eight months (May to December, 2020). Respiratory samples, received from indoor patients with history of ARI, were processed for COVID-19 (TrueNat Real Time Polymerase chain reaction) as well as for bacterial and fungal cultures following Standard Operating Procedures (SOP). Identification and susceptibility pattern was evaluated by Vitek2 compact system (bioMérieux, Inc. Durham, North Carolina/USA). Quality control strains used were American Type Culture Collection (ATCC) Staphylococcus aureus 29213, Escherichia coli 25922 and Candida parapsilosis ATCC 22019. Minimum Inhibitory Concentration (MIC) levels were standardised as per Clinical and Laboratory Standards Institute (CLSI) guideline, 2020. All statistical analysis was done by Chi-square test using Software Statistical Package for the Social Sciences (SPSS) version 22.0. Results: Total patients admitted with the history of ARI were 542; COVID-19 Positive Group (CPG) included 115 (21.22%) while COVID-19 Negative Group (CNG) included 427 (78.78%). Growth in bacterial and fungal cultures in CPG was 59.13% (68/115) while in CNG; it was 47.78% (204/427). Among the bacterial isolates, most common isolate was Klebsiella pneumoniae {CPG: 41.93% (26/62); CNG: 36.72% (76/207)}, followed by Pseudomonas aeruginosa {CPG: 33.87% (21/62); CNG: 31.88% (66/207)}. Fungal isolates in CPG was 19.48% (15/77) (p-value 0.0445). On comparing Antimicrobial Susceptibility (AST) pattern of Enterobacterales in both CPG (n=36) and CNG (n=102), no statistically significant difference was observed. Co-morbid conditions were found mostly in CNG 89% (140/158) with ARI while only 11% (18/158) was found in CPG. Conclusion: Secondary respiratory infections are quite common amongst COVID-19 positive patients. However, growth in culture, type of isolates, Antimicrobial Resistance (AMR) was almost similar with COVID-19 non infected patients admitted with ARI. Co-morbidity had the similar impact as COVID-19 infection with respect to co-infections. [ABSTRACT FROM AUTHOR]

This study demonstrated an environmentally responsible, inexpensive and simple one-step hydrothermal method to synthesize biocompatible fluorescent carbon quantum dots (CQDs) from Aegle marmelos fruit extract. The near-spherical CQDs were discovered to have a naturally distributed size of 3–6 nm, were unintentionally doped with heteroatoms (Ca, K, and N) without the need for doping element precursors due to mineral contents in extract, had a quantum yield of about 4.06%, strong photostability, and excellent water solubility. Several morphological, compositional, physicochemical, and optical properties were studied. Other variables influencing CQD photoluminescence, such as hydrothermal process parameters and pH sensitivity, were also examined. Zeta potential analysis showed a negative surface charge with a zeta potential value of −5.29 mV and good dispersibility in aqueous solution. Furthermore, as an alternative to organic or synthetic probes, there is a huge need for the development of simple, affordable, and non-destructive fluorescent biomarkers. As-synthesized Ca, K, N-doped CQDs have demonstrated good fluorescent staining abilities and may be employed as a helpful probe for bio-imaging of cancer cells and other organisms. Cell survival and cytotoxicity were found to be satisfactory, with 90% of SH-SY5Y and HCT-116 cells surviving, compared to 63–77% for the other organisms, even at higher dosages (200 µg/mL) for up to 4 days. [Display omitted] • A facile heteroatom doped CQDs have been synthesized from Aegle marmelos. • Hydrothermal process dependent and pH responsive PL were examined. • Bio-imaging of cancer cells and other living organisms are demonstrated. • Cytotoxicity were found over 90% of SH-SY5Y and HCT-116 cancer cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biocompatible fluorescent N,K,Ca-doped CQDs derived from Chenopodium album. • Fluorescence quantum yield up to 48.12 % was achieved. • Bioimaging of SH-SY5Y human neuroblastoma cells, bacteria, fungal, and plant cells. • The cytotoxicity and cell viability have also been examined. This study demonstrated an economical, ecologically sustainable, and simple method for producing biocompatible fluorescent carbon quantum dots (CQDs) co-doped with N, K, and Ca from bathua (Chenopodium album), a popular medicinal herb leaf extract and nutritious vegetable. The nearly spherical shaped CQDs were discovered to be 3–5 nm in size in nature, with a quantum yield of around 48.12%, robust photo-stability, and excellent water solubility. Various morphological, compositional, physicochemical and optical characteristics were investigated. Additional factors affecting the photoluminescence of CQDs, such as hydrothermal process parameters, pH, and solvent sensitivity, were investigated further. Moreover, the newly synthesized N, K, Ca-doped CQDs were demonstrated to be a useful fluorescent nanoprobe for in vitro cellular imaging of SH-SY5Y human neuroblastoma cells, as well as other living organisms such as bacteria, fungal, and plant cells, as a cost-effective alternative to organic or synthetic fluorescent probes. Cell survival and cytotoxicity were found to be acceptable, with 95% of SH-SY5Y and HCT-116 cells surviving and other organisms able to withstand higher doses (10.9 mg/mL) for up to 4 days. [ABSTRACT FROM AUTHOR]