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1.
Phys Chem Chem Phys ; 25(47): 32503-32514, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37997153

RESUMO

Metal-organic framework (MOF) based proton conductors are synthesized by the Avrami model (time-temperature modalities). Our objective here is to obtain a material with high proton conductivity in anhydrous conditions, improved catalytic behaviour and morphology control of conductivity, band gap and catalysis. For this purpose, we try to understand the role of morphology on mass transportation using computational fluid dynamics and the experimental realisation using the synthesis of MOF membranes with high protonic conductivity. In order to alter the morphology, the membranes are synthesized from protic ionic liquid (dimethyl ethyl amine H2PO4) and metal ion (Co3O4) at different temperatures and duration. A high protonic conductivity of 0.0286 S cm-1 with a high transference number >0.99 is observed in anhydrous conditions with the change in morphology. Furthermore, catalyst properties along with high activity (Tafel slope = 39 mV decade-1) with the alteration in morphology are also investigated in detail and observed adsorption governed conduction. This adsorption governed conduction is verified using computational fluid dynamics simulations with the alteration in morphology. This study suggests that morphology not only plays a pivotal role in obtaining a robust proton exchange membrane, it also improves the catalytic functionality and stability of the membrane.

2.
J Family Med Prim Care ; 11(3): 825-827, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35495848

RESUMO

Despite recent breakthroughs in the detection and treatment during the COVID-19 pandemic, mucormycosis is a serious infection with a high death rate. It is a filamentous fungal infection from the zygomycetes class of order mucorales. It is a fatal fungal infection with a 50% or higher overall fatality rate. Mucormycosis is a fungal infection caused by mucor, which is a mold that can be found in soil, rotting fruits, and vegetables. It can primarily affect the brain, lungs, and sinuses. It is very much fatal in patients with diabetes or who are highly immunocompromised such as patients with cancer. In addition to more than 50% mortality rate, surgical intervention may require necrotic tissue removal, which leads to severely disfiguring surgery.

3.
Plant Biol (Stuttg) ; 23 Suppl 1: 181-192, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33135242

RESUMO

Salinity is a severe threat to crop growth, development and even to world food sustainability. Plant possess natural antioxidant defense tactics to mitigate salinity-induced oxidative stress. Phenolic compounds are non-enzymatic antioxidants with specific roles in protecting plant cells against stress-mediated reactive oxygen species (ROS) generation. Coumarin (COU) is one of these compounds, however, to date, little is known about antioxidative roles of exogenous COU in enhancing plant tolerance mechanisms under salt stress. The involvement of COU in increasing tomato salt tolerance was examined in the present study using COU as a pre-treatment at 20 or 30 µM for 2 days against salt stress (100 or 160  NaCl; 5 days). The COU-mediated stimulation of plant antioxidant defence and glyoxalase systems to suppress salt-induced ROS and methylglyoxal (MG) toxicity, respectively, were the main hypotheses examined in the present study. Addition of COU suppressed salt-induced excess accumulation of ROS and MG, and significantly reduced membrane damage, lipid peroxidation and Na+ toxicity. These results demonstrate COU-improved plant growth, biomass content, photosynthetic pigment content, water retention and mineral homeostasis upon imposition of salinity. Finally, this present study suggests that COU has potential roles as a phytoprotectant in stimulating plant antioxidative mechanisms and improving glyoxalase enzyme activity under salinity stress.


Assuntos
Antioxidantes , Solanum lycopersicum , Cumarínicos , Homeostase , Salinidade
4.
Plant Signal Behav ; 13(5): e1477905, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29939817

RESUMO

Sulfur (S) is a macronutrient for the plant, which has an immense role in basic plant processes and regulation of several metabolic pathways. It has also a major role in providing protection against adverse conditions. Sulfur-containing amino acids and metabolites maintain plant cell mechanisms to improve stress tolerance. It interacts with several biomolecules such as phytohormones, polyamines, nitric oxide (NO), and even with other plant nutrients, which can produce some derivatives those are essential for abiotic stress tolerance. Different S derivatives stimulate signaling cascades, for the upregulation of different cellular messengers such as abscisic acid, Ca2+, and NO. Sulfur is also known to interact with some essential plant nutrients by influencing their uptake and transport, hence, confers nutrient homeostasis efficiencies. This review focuses on how S is interacted with several signaling molecules like NO, glutathiones, phytohormones, hydrogen sulfide, polyamines, etc. This is a concise summary aimed at guiding the researchers to study S-related plant processes in the light of abiotic stress tolerance.


Assuntos
Reguladores de Crescimento de Plantas/metabolismo , Plantas/metabolismo , Enxofre/metabolismo , Glutationa/metabolismo , Óxido Nítrico/metabolismo , Transdução de Sinais/fisiologia , Estresse Fisiológico/fisiologia
5.
Mymensingh Med J ; 26(1): 17-20, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28260750

RESUMO

This case-control study was carried out in the Department of Biochemistry, Mymensingh Medical College in collaboration with the Department of Cardiology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from January 2015 to December 2015. The aim of the study was to explore the serum zinc status among acute myocardial infarction (AMI) patients as a means to monitor the possibility of management of these patients. A total of 120 subjects were included in this study. Among them 60 were diagnosed AMI patients denoted as case group and 60 were normal healthy individuals denoted as control group. Serum zinc was determined by colorimetric method from each sample. Statistical analysis was performed by SPSS windows package, version 20. Among the study groups the Mean±SD values of serum zinc were 64.98±18.86µmol/L and 97.14±7.97µmol/L in case and control group respectively. Analysis showed that the mean serum zinc level was significantly (p<0.01) decreased in AMI patients in comparison to that of control group.


Assuntos
Infarto do Miocárdio , Zinco , Bangladesh , Estudos de Casos e Controles , Humanos , Masculino , Infarto do Miocárdio/sangue , Zinco/sangue
6.
Mymensingh Med J ; 25(4): 611-614, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27941718

RESUMO

This case control study was carried out in the Department of Biochemistry, Mymensingh Medical College in collaboration with the Department of Cardiology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from January 2015 to December 2015. The aim of the study was to explore the serum copper status among acute myocardial infarction (AMI) patients as a means to monitor the possibility of management of these patients. A total of 120 subjects were included in this study. Among them 60 were diagnosed AMI patients denoted as case group and 60 were normal healthy individuals denoted as control group. Serum copper determined by colorimetric method from each sample. Statistical analysis was performed by SPSS windows package, version 20. Among the study groups the mean serum copper levels were 150.30±26.16 and 103.65±9.38 in case and control group respectively. Analysis showed that the mean serum copper level was significantly (p<0.01) increased in AMI patients in comparison to that of control group.


Assuntos
Infarto do Miocárdio , Bangladesh , Estudos de Casos e Controles , Cobre , Humanos , Masculino
7.
J Clin Endocrinol Metab ; 100(4): E638-45, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25581598

RESUMO

CONTEXT: Inactivating mutations have been reported in subjects with primary/secondary amenorrhea, whereas activating mutations are rare and seen only in women with ovarian hyperstimulation syndrome (OHSS). In the present study, we describe the functional characterization of the two mutations Val(514)Ala (novel mutation) and Ala(575)Val in FSH receptor (FSHR) identified in women with OHSS developed during in vitro fertilization and primary amenorrhea, respectively. OBJECTIVE: The objective of the investigation was to study the effect of mutations (514 and 575) on FSHR activity by in vitro functional studies. SETTING: The study was conducted at an academic research institute and a private in vitro fertilization clinic. METHODS: The site-directed mutagenesis was carried out to generate the mutations at position 514 and 575 in pSG5-FSHR construct. Stable cell lines expressing wild type or each of the mutant receptor were generated using Chinese hamster ovary cells. Functional characteristics of both the mutant receptors were assessed by a radioreceptor assay and a cAMP assay. RESULTS: The mutant receptor 514 showed increased cell surface expression as compared with the wild-type (WT) receptor. Although the hormone binding characteristics were similar to the WT receptor, its signaling activity was distinctly higher at lower dose of FSH as monitored by a cAMP assay. On the other hand, the mutant receptor 575 showed lower cell surface expression and higher internalized hormone receptor complex. Additionally, a dose-dependent increase in the cAMP accumulation was not observed in the case of this mutant as compared with WT. CONCLUSION: OHSS and primary amenorrhea observed in the two affected women, respectively, could be attributed to the functional characteristics of respective mutant FSHR.


Assuntos
Amenorreia/genética , Infertilidade Feminina/genética , Mutação de Sentido Incorreto , Síndrome de Hiperestimulação Ovariana/genética , Receptores do FSH/genética , Adolescente , Adulto , Alanina/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Sequência de Bases , Células CHO , Cricetinae , Cricetulus , Feminino , Humanos , Transfecção , Valina/genética
8.
J Appl Phys ; 69(8): 6031-3, 1991 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11538293

RESUMO

Magnetic susceptibility measurements of high purity MgO single crystals (<50-wt. ppm transition metals) by means of a vibrating-sample magnetometer shows an anomaly at 800 K. At the same temperature the electric conductivity increases anomalously, the static dielectric constant epsilon increases from 9 to approximately 150, a pronounced positive surface charge appears, and Fe2+ in the MgO matrix oxidizes to Fe3+. The data are consistent with O2(2-) (peroxy) defects, representing self-trapped, spin-paired positive holes at Mg2+ vacancy sites. Diamagnetic at low temperatures, the holes start to decouple their spins > 600 K, probably forming at first V0 centers (two O- at an Mg2+ vacancy), then V- centers (single O- at an Mg2+ vacancy), and releasing mobile O- states. These O- represent itinerant charge carriers on acceptor levels near the O 2p-dominated valence band and conduct by O- /O2- valency fluctuations. The O- concentration is of the order of 8 X 10(19) cm-3.


Assuntos
Eletricidade , Óxido de Magnésio/análise , Magnetismo , Cristalização , Condutividade Elétrica , Elétrons , Magnésio/análise , Oxigênio/análise , Temperatura
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