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1.
Nano Lett ; 22(19): 7798-7803, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36154175

RESUMO

Color-center-based single-photon emitters in hexagonal boron nitride (h-BN) have shown promising photophysical properties as sources for quantum light emission. Despite significant advances toward such a goal, achieving lifetime-limited quantum light emission in h-BN has proven to be challenging, primarily due to various broadening mechanisms, including spectral diffusion. Here, we propose and experimentally demonstrate suppression of spectral diffusion by applying an electrostatic field. We observe both Stark shift tuning of the resonant emission wavelength and emission line width reduction (down to 89 MHz) nearly to the homogeneously broadened lifetime limit. Finally, we find a cubic dependence of the line width with respect to temperature at the homogeneous broadening regime. Our results suggest that field tuning in electrostatically gated heterostructures is promising as an approach to control the emission characteristics of h-BN color centers, removing spectral diffusion and providing the energy tunability necessary for integrate of quantum light emission in nanophotonic architectures.

2.
Water Sci Technol ; 88(6): 1564-1577, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37768755

RESUMO

Binary zinc oxide (ZnO) nanocomposites with different noble metals, silver (Ag) and ruthenium (Ru), were prepared from an aqueous leaf extract of Callistemon viminalis. The biosynthesized photocatalysts were characterized and examined for their photocatalytic disinfection against Escherichia coli isolated from hospital wastewater. The influence of the different noble metals showed a difference in physicochemical characteristics and photocatalytic efficiency between Ag-ZnO and Ru-ZnO. The photocatalytic degradation of methylene blue and photocatalytic disinfection were found to be in the order Ag-ZnO > Ru-ZnO > ZnO. The photocatalytic disinfection of Ag-ZnO reached a 75% reduction in 60 min, compared to 34 and 9% reductions of Ru-ZnO and ZnO, respectively. The kinetic reaction rate for the photocatalytic disinfection of Ag-ZnO was found to be 2.8 times higher than that of Ru-ZnO. The outstanding photocatalytic activity of Ag-ZnO over Ru-ZnO was attributed to higher crystallinity, greater UVA adsorption capacity, smaller particle size, and the additional antimicrobial effect of Ag itself. The C. viminalis-mediated Ag-ZnO nanocomposites can be a potential candidate for photocatalytic disinfection of drug-resistant E. coli in hospital wastewater.

3.
Cryobiology ; 89: 35-41, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31173735

RESUMO

A study was conducted to establish a sustainable and effective manual freezing technique for cryopreservation of Bangladeshi ram semen. Three diluents and freezing techniques were tested, both as treatment combinations (diluent × freezing technique) and fixed effects (diluent or freezing technique) on post-thaw sperm motility (SM), viability (SV), plasma membrane integrity (SPMI) and acrosome integrity (SAI). Ten rams were selected, based on semen evaluation. Eight ejaculates were used for each treatment combination. Semen samples were diluted using a two-step protocol for home-made Tris-based egg yolk (20%, v/v) diluents: D1 (7% glycerol, v/v) and D2 (5% glycerol, v/v), and one-step for commercial diluent: D3 (Triladyl®, consists of bi-distilled water, glycerol, tris, citric acid, fructose, spectinomycin, lincomycin, tylosin and gentamycin) at 35 °C. Fraction-A (without glycerol) was added at 35 °C, and following cooling of sample to 5 °C (-0.30 °C/min), Fraction-B (with glycerol) was added. The diluted semen samples were aspirated into 0.25 ml French straws, sealed, and equilibrated at 5 °C for 2 h. The straws were frozen in liquid nitrogen (LN) vapour, in a Styrofoam box. The freezing techniques were; One-step (F1): at -15.26 °C/min from +5 °C to -140 °C; Two-step (F2): at -11.33 °C/min from +5 °C to -80 °C, and -30 °C/min from -80 °C-140 °C; and Three-step (F3): at -11.33 °C/min from +5 °C to -80 °C, at -26.66 °C/min from to -80 °C to -120 °C, and at -13.33 °C/min from -120 °C to -140 °C. Two semen straws from each batch were evaluated before and after freezing. The group F3D3 exhibited significantly higher (p < 0.05) post-thaw SM 63.1 ± 2.5%, SV 79.0 ± 2.1% and SPMI 72.9 ± 1.7%, whereas SAI 72.9 ± 1.7% was significantly higher (p < 0.05) in group F3D2. The freezing technique F2 and F3 had significantly higher (p < 0.05) post-thaw sperm values compared to F1. The post-thaw SM and SV were above 50% and 65% with the freezing technique F2 and F3 but differed non-significant. The SPMI 67.6 ± 2.0% and SAI 76.1 ± 1.4% were significantly higher (p < 0.05) with F3. Likewise, the diluent D2 and D3 had significantly higher (p < 0.05) post-thaw sperm values compared to D1. The post-thaw SM, SV and SPMI were above 50%, 65% and 55% with the diluents D2 and D3 but differed non-significant. The SAI 76.1 ± 1.1% was significantly higher (p < 0.05) with D3. We concluded that the use of a simple home-made Tris-based diluent containing 20% (v/v) egg yolk and 5% glycerol (v/v), two-step dilution and a three-step freezing technique is a sustainable and effective method for freezing ram semen. For further validation, the fertility of ewes artificially inseminated with the frozen semen will be observed.


Assuntos
Criopreservação/métodos , Crioprotetores/farmacologia , Preservação do Sêmen/métodos , Sêmen/fisiologia , Motilidade dos Espermatozoides/efeitos dos fármacos , Acrossomo/fisiologia , Animais , Bangladesh , Membrana Celular/efeitos dos fármacos , Ácido Cítrico , Gema de Ovo , Fertilidade , Congelamento , Glicerol/farmacologia , Masculino , Nitrogênio , Ovinos
4.
RSC Adv ; 14(16): 11017-11026, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38586445

RESUMO

Antibiotics are of great interest due to antibiotic-resistant problems around the globe due to bacterial resistance to conventional antibiotics. In this study, a novel green biosynthesis of silver-ruthenium bimetallic zinc oxide nanocomposite using Callistemon viminalis leaf extract as a reducing agent using zinc nitrate hexahydrate, silver nitrate, and ruthenium(iii) chloride as capping agents was reported. The results demonstrated that the surface morphology of the prepared bimetallic nanocomposite by scanning electron microscopy was hexagonal in shape for zinc nanoparticle, rectangular in shape for silver nanoparticle, and tetragonal in shape for ruthenium nanoparticle, having an average surface size 25, 35, and 55 nm, respectively. Fourier transform infrared analysis confirmed the presence of compounds containing alkene, halo-, sulfoxide, phenol, nitro-, phenyl-ester, carboxylic acid, amines, and alcohols which act as functional groups attached to the surface of nanocomposites. Results from X-ray diffraction analysis found 81.12% crystallinity and hexagonal structure of zinc nanoparticles, rectangular structure of silver nanoparticles, and tetragonal structure of ruthenium nanoparticles, which are also similar to the results from transmission electron microscopy analysis. The average size distribution by dynamic light scattering of silver-ruthenium bimetallic zinc oxide nanocomposite was 255 nm, which confirms the biosynthesis of non-uniform size. Photo-disinfection activity of a silver-ruthenium bimetallic zinc oxide nanocomposite against Escherichia coli bacteria isolated from hospital wastewater under dark and ultraviolet-A irradiation conditions was observed. The antibacterial activity was calculated at 2.42704239, ensuring the silver-ruthenium bimetallic zinc oxide nanomaterials have photo-disinfection properties. The results from this study revealed that the developed novel antibacterial nanocomposite of silver-ruthenium bimetallic zinc oxide is useful in nanocoating photocatalytic Escherichia coli disinfection and can be applied to disinfect surfaces.

5.
Cureus ; 16(1): e52064, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38348001

RESUMO

Objective This study aimed to evaluate and analyze the characteristics of Indian patients with type 2 diabetes mellitus (T2DM) in relation to the usage patterns of a fixed-dose combination (FDC) of glimepiride, metformin, and voglibose. Methods This retrospective, observational, multicentric analysis was conducted from March 2021 to September 2022. It involved adult patients (aged ≥18 years) with T2DM from 424 sites including a combination of hospitals and privately owned clinics across India to ensure comprehensive representation of the patient population The study included patients who had been treated with FDC of glimepiride, metformin, and voglibose of varying strengths for T2DM management. Data were collected through a pre-designed electronic form, which captured demographic details, medical history, T2DM history, and drug usage patterns from medical records. The collected data were then analyzed using descriptive statistical methods. Results This analysis encompassed a final cohort of 8,587 patients out of which 5,840 were males with a mean age of 54.91 years and a BMI of 28.41 kg/m2. Newly diagnosed T2DM cases were 35.23%, 54.79% had a family history, and 61.21% had risk factors such as smoking, sedentary lifestyle, and others. Dyslipidemia (13.94%) and neuropathy (14.48%) were common comorbidities. The most prescribed FDC was 1 mg glimepiride, 500 mg metformin, 0.2 mg voglibose (40.14%), the most preferred dosing frequency was once daily (52.92%) and the most common duration of treatment was one to three months (48.78%). Conclusion In routine Indian clinical practice, the triple drug FDC of 1 mg glimepiride, 500 mg metformin, and 0.2 mg voglibose, taken once daily for one to three months, was the most common treatment for both newly diagnosed and long-standing diabetes patients.

6.
Indian J Med Sci ; 65(11): 497-501, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23525027

RESUMO

BACKGROUND: The chronic debilitating conditions, i.e., diabetes and depression are associated with significant morbidity, mortality, and healthcare costs. Both these interlinked chronic conditions contribute to their worst outcomes. AIMS: The objective of the present study was to analyze the frequency of depression in diabetes and its correlation with demographic details like age, sex, domicile, education, income, and marital status. SETTINGS AND DESIGN: The study was conducted in the private diabetic clinic in outer Delhi (Rohini). SUBJECTS AND METHODS: Totally, 250 patients attending the outpatient department of private diabetic clinic were assessed with Beck Depression Inventory Scale which was a 21-question multiple-choice self-report inventory. RESULTS: Among the study population, 11.6% of the patients had co-morbid depression with more prevalence in females when compared with males. The demographic analysis revealed that depression incidence was higher in urban population, lower socio-economic class, and in patients with diabetes more than 5 years when compared with their counterparts and similar in graduate and undergraduate student population. Interestingly, the numbers of depression cases were found only in married population contrary to none in unmarried category. CONCLUSION: Present study concluded that co-morbidity of depression is prevalent in diabetic population with three times higher frequency than the considered feature of mild depression.


Assuntos
Depressão/epidemiologia , Diabetes Mellitus/psicologia , População Urbana/estatística & dados numéricos , Feminino , Humanos , Incidência , Índia/epidemiologia , Masculino , Estado Civil , Prevalência , Fatores Sexuais , Classe Social , Fatores de Tempo
7.
Clin Ther ; 33(3): 378-90, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21600390

RESUMO

BACKGROUND: Mycophenolate mofetil (MMF) is an immunosuppressant indicated for prophylaxis of acute organ transplant rejection. Generic MMF is less costly than the branded product, but European regulatory authorities require bioequivalence studies for the marketing of generics. OBJECTIVES: The aims of the 2 studies reported were to assess the dissolution and bioavailability of a generic (test) and branded (reference) formulation of MMF 500 mg. METHODS: An in vitro analytical dissolution profile test was conducted comparing 500 mg MMF test drug with a reference drug. A separate single-dose, randomized, open-label, 2-way crossover study involving fasting, healthy, adult male volunteers was conducted. Two study periods-1 test drug period and 1 reference drug period-were separated by a 14-day washout period. Blood samples were collected for up to 60 hours after drug administration for the determination of MMF and mycophenolic acid (MPA) pharmacokinetics. Concentrations of the analytes were determined using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method; pharmacokinetic parameters were calculated using noncompartmental analysis; C(max), AUC(0-t), and AUC(0-∞) were the primary evaluation criteria. Bioequivalence was assumed if the 90% confidence intervals (CIs) for the test/reference ratios of natural logarithm transformed values (obtained using ANOVA) were between 80% and 125%, per European regulations for bioequivalence. Tolerability was monitored throughout the study. RESULTS: The dissolution profiles of the test drug matched those of the reference drug at 4 pH levels. In the bioequivalence study, a total of 126 male subjects were dosed, and 117 subjects completed the study. The 90% CIs for MPA were C(max), 94.13% to 116.46%; AUC(0-t), 98.26% to 102.36%; and AUC(0-∞), 97.85% to 101.99%. These values met with the European regulatory definition of bioequivalence. Reported adverse events were similar in both the test and reference drugs. CONCLUSIONS: This single-dose study found that the test and reference MMF 500 mg tablets met the European regulatory criteria for assuming bioequivalence in fasting, healthy, male subjects. Both formulations were well tolerated. (Clinical Trials Registry - India [CTRI]: 2011/03/002211).


Assuntos
Imunossupressores/farmacocinética , Ácido Micofenólico/análogos & derivados , Administração Oral , Adolescente , Adulto , Química Farmacêutica , Estudos Cross-Over , Jejum , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/sangue , Imunossupressores/química , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/administração & dosagem , Ácido Micofenólico/sangue , Ácido Micofenólico/química , Ácido Micofenólico/farmacocinética , Solubilidade , Comprimidos , Adulto Jovem
8.
DNA Res ; 16(6): 325-43, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19861381

RESUMO

Chargaff's rule of intra-strand parity (ISP) between complementary mono/oligonucleotides in chromosomes is well established in the scientific literature. Although a large numbers of papers have been published citing works and discussions on ISP in the genomic era, scientists are yet to find all the factors responsible for such a universal phenomenon in the chromosomes. In the present work, we have tried to address the issue from a new perspective, which is a parallel feature to ISP. The compositional abundance values of mono/oligonucleotides were determined in all non-overlapping sub-chromosomal regions of specific size. Also the frequency distributions of the mono/oligonucleotides among the regions were compared using the Kolmogorov-Smirnov test. Interestingly, the frequency distributions between the complementary mono/oligonucleotides revealed statistical similarity, which we named as intra-strand frequency distribution parity (ISFDP). ISFDP was observed as a general feature in chromosomes of bacteria, archaea and eukaryotes. Violation of ISFDP was also observed in several chromosomes. Chromosomes of different strains belonging a species in bacteria/archaea (Haemophilus influenza, Xylella fastidiosa etc.) and chromosomes of a eukaryote are found to be different among each other with respect to ISFDP violation. ISFDP correlates weakly with ISP in chromosomes suggesting that the latter one is not entirely responsible for the former. Asymmetry of replication topography and composition of forward-encoded sequences between the strands in chromosomes are found to be insufficient to explain the ISFDP feature in all chromosomes. This suggests that multiple factors in chromosomes are responsible for establishing ISFDP.


Assuntos
Cromossomos de Archaea/genética , Cromossomos Bacterianos/genética , Cromossomos/genética , DNA Complementar/genética , Eucariotos/genética , Oligonucleotídeos/genética , Archaea/genética , Bactérias/genética , Composição de Bases/genética , Sequência de Bases , Replicação do DNA , Oligonucleotídeos/análise
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