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1.
Nanoscale ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767603

RESUMO

One of the most coveted objectives in the realm of energy conversion technologies is the development of highly efficient and economically viable electrocatalysts for the oxygen evolution reaction. The commercialization of such techniques has thus far been impeded by their slow response kinetics. One of the many ways to develop highly effective electrocatalysts is to judiciously choose a coupling interface that maximizes catalyst performance. In this study, the in situ electrochemical phase transformation of MnCo2O4-Ni3N into MnCo2O4-NiOOH is described. The catalyst has an exceptional overpotential of 224 mV to drive a current density of 10 mA cm-2. Strong interfacial contact is seen in the MnCo2O4-Ni3N catalyst, leading to a considerable electronic redistribution between the MnCo2O4 and Ni3N phases. This causes an increase in the valence state of Ni, which makes it an active site for the adsorption of *OH, O*, and *OOH (intermediates). This charge transfer facilitates the rapid phase transformation to form NiOOH from Ni3N. At a higher current density of 300 mA cm-2, the catalyst remained stable for a period of 140 h. DFT studies also revealed that the in situ-formed NiOOH on the MnCo2O4 surface results in superior OER kinetics compared to that of NiOOH alone.

2.
Sci Adv ; 9(41): eadi1453, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37831768

RESUMO

Extracting the relation between microstructural features and resulting material properties is essential for advancing our fundamental knowledge on the mechanics of cellular metamaterials and to enable the design of novel material systems. Here, we present a unified framework that not only allows the prediction of macroscopic properties but, more importantly, also reveals their connection to key morphological characteristics, as identified by the integration of machine-learning models and interpretability algorithms. We establish the complex manner in which strut orientation can be critical in determining effective stiffness for certain microstructures and highlight cellular metamaterials with counterintuitive material behavior. We further provide a refined version of Maxwell's criteria regarding the rigidity of frame structures and their connection to cellular metamaterials. By examining the shear moduli of these metamaterials, the mean cell compactness emerges as a key morphological feature. The generality of the proposed framework allows its extension to broader classes of architected materials as well as different properties of interest.

3.
Vasc Endovascular Surg ; 55(8): 817-822, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34151672

RESUMO

OBJECTIVE: The use of drug coated balloon (DCB) for angioplasty has shown superior efficacy against plain balloons for treating complex infrainguinal arterial disease. We report and compare the clinical outcomes following application of DCB(Paclitaxel) and plain angioplasty (POBA) in our tertiary care centre. METHODS: A retrospective, single centre analysis of 301 patients with chronic limb-threatening ischemia involving the infrainguinal segment was conducted between September 2014 and September 2018, after approval from the Institutional review board. We analyzed clinical outcomes by measuring postoperative ABI improvement, restenosis requiring reintervention procedure, minor and major amputations at the end of 18 months. . To find the association between the group variables (POBA and DCB) and other risk variables, Chi-square test/Fisher's exact test was used. Multivariable logistic regression analysis was used. RESULTS: Patients who underwent treatment with plain balloon (POBA) and DCB(Paclitaxel) angioplasty were 246(81.7%) and 55(18.3%) respectively. Our study group was predominantly male (Male: Female = 6.7:1), most patients were more than 50 years of age (n = 251, 83.4%). Smoking (n = 199, 66.1%) and diabetes (n = 210, 69.8%) were the most common atherosclerotic risk factors. Postoperative Ankle Brachial Pressure Index (ABI) improvement were similar in both groups (POBA = 57.7%; DCB = 69.8%; p = 0.103). Minor and major amputations following POBA were 26% and 22%; and DCB were 12.7% and 16.4% respectively. Re-stenosis requiring a re-interventional procedure within 18 months was 15%, (n = 37) following POBA; and 12.7% (n = 7) following DCB (p = 0.661). CONCLUSIONS: This retrospective study shows similar clinical limb related outcomes following POBA and DCB at 18 months. However, our comparative analysis between the POBA and DCB groups was totally unadjusted and not adjusted for common confounders such as age and sex. Hence, for one to draw definitive conclusions leading to changes in clinical practice; a randomized, prospective study with a larger patient cohort is needed.


Assuntos
Angioplastia com Balão , Isquemia Crônica Crítica de Membro , Materiais Revestidos Biocompatíveis , Angioplastia com Balão/métodos , Isquemia Crônica Crítica de Membro/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
4.
Behav Pharmacol ; 29(6): 482-492, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29570113

RESUMO

The objective of this study was to develop a rapid, 1-day learning and memory assay in mice that is sensitive to the effects of compounds that could impair or enhance acquisition and retrieval. Swiss-Webster, male mice were placed in experimental chambers for a 1-h acquisition session with an intermittent, audible tone. If a nose-poke response occurred during the tone, an Ensure water solution was presented. After 1 h, the mice returned to the chambers for 2 h. Drugs were injected before or after sessions to determine the effects on acquisition and/or retrieval. Mice injected with saline learned a nose-poke response as measured by decreased latencies to earn 10 reinforcers, increased reinforced response rates, and decreased nonreinforced response rates. Scopolamine and acetazolamide impaired retrieval of the nose-poke response, whereas ketamine only modestly impaired retrieval. Doses of 8-OH-DPAT or the novel carbonic anhydrase activator, MAI27, either had no effect or impaired some measures of responding. Neither 8-OH-DPAT nor MAI27 were able to prevent the modest impairments produced by ketamine. The simple, 1-day operant task is a rapid assay that can be used as an initial screen to test the effects of learning and memory disruptors and potentially enhancers.


Assuntos
Condicionamento Operante/fisiologia , Deficiências da Aprendizagem/tratamento farmacológico , Deficiências da Aprendizagem/fisiopatologia , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/fisiopatologia , 8-Hidroxi-2-(di-n-propilamino)tetralina/farmacologia , Adjuvantes Anestésicos/farmacologia , Animais , Condicionamento Operante/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ativadores de Enzimas/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ketamina/farmacologia , Deficiências da Aprendizagem/induzido quimicamente , Masculino , Transtornos da Memória/induzido quimicamente , Camundongos , Camundongos Endogâmicos , Reforço Psicológico , Escopolamina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia
5.
Med Hypotheses ; 103: 39-45, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28571806

RESUMO

New drugs are urgently needed to cure tuberculosis (TB) in a short period of time without causing any adverse effects since currently used drugs for the treatment of multi drug-resistant TB cause several adverse effects with poor success rate. Therefore, we aimed to prioritize known drugs towards repurposing for TB by employing bioinformatics approach in the present study. A total of 1554 FDA approved drugs were obtained from DrugBank. Serine/threonine-protein kinase, pknB (Rv0014c) of Mycobacterium tuberculosis (Mtb) was selected as the drug target since it involves in several vital functions of the Mtb. All of the 1554 drugs were subjected to molecular docking with pknB. Glide and AutoDock Vina were employed using rigid docking followed by induced fit docking protocol for prioritization of drugs. Out of 14 drugs prioritized, six are suggested as high-confident drugs towards repurposing for TB as they were consistently found within top 10 ranks of both methods, and strongly binding in the active site of the pknB. We also found atorvastatin as one of the high-confident drugs, which has already been demonstrated to be active against Mtb under in vitro conditions by other researchers. Therefore, we propose that the prioritized six high-confident drugs as potential candidates for repurposing for TB and suggest for further experimental studies. We also suggest that the bioinformatics procedure we have employed in this study could be effectively applied for prioritization of drugs for other diseases.


Assuntos
Biologia Computacional/métodos , Reposicionamento de Medicamentos , Tuberculose/tratamento farmacológico , Atorvastatina/farmacologia , Aprovação de Drogas , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Conformação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Estados Unidos , United States Food and Drug Administration
6.
Bioinformation ; 12(8): 359-367, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28275291

RESUMO

Repurposing has gained momentum globally and become an alternative avenue for drug discovery because of its better success rate, and reduced cost, time and issues related to safety than the conventional drug discovery process. Several drugs have already been successfully repurposed for other clinical conditions including drug resistant tuberculosis (DR-TB). Though TB can be cured completely with the use of currently available anti-tubercular drugs, emergence of drug resistant strains of Mycobacterium tuberculosis and the huge death toll globally, together necessitate urgently newer and effective drugs for TB. Therefore, we performed virtual screening of 1554 FDA approved drugs against murE, which is essential for peptidoglycan biosynthesis of M. tuberculosis. We used Glide and AutoDock Vina for virtual screening and applied rigid docking algorithm followed by induced fit docking algorithm in order to enhance the quality of the docking prediction and to prioritize drugs for repurposing. We found 17 drugs binding strongly with murE and three of them, namely, lymecycline, acarbose and desmopressin were consistently present within top 10 ranks by both Glide and AutoDock Vina in the induced fit docking algorithm, which strongly indicates that these three drugs are potential candidates for further studies towards repurposing for TB.

7.
Amino Acids ; 48(3): 689-696, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26543027

RESUMO

The ß-lactam antibiotic ceftriaxone (CTX) reduces cocaine reinforcement and relapse in preclinical assays through a mechanism involving activation of glutamate transporter subtype 1 (GLT-1). However, its poor brain penetrability and intravenous administration route may limit its therapeutic utility for indications related to CNS diseases. An alternative is clavulanic acid (CA), a structural analog of CTX that retains the ß-lactam core required for GLT-1 activity but displays enhanced brain penetrability and oral activity relative to CTX. Here, we tested the hypothesis that CA (1, 10 mg/kg ip) would enhance GLT-1 expression and decrease cocaine self-administration (SA) in mice, but at lower doses than CTX. Experiments revealed that GLT-1 transporter expression in the nucleus accumbens of mice treated with repeated CA (1, 10 mg/kg) was enhanced relative to saline-treated mice. Repeated CA treatment (1 mg/kg) reduced the reinforcing efficacy of cocaine (0.56 mg/kg/inf) in mice maintained on a progressive-ratio (PR) schedule of reinforcement but did not affect acquisition of cocaine SA under fixed-ratio responding or acquisition or retention of learning. These findings suggest that the ß-lactamase inhibitor CA can activate the cellular glutamate reuptake system in the brain reward circuit and reduce cocaine's reinforcing efficacy at 100-fold lower doses than CTX.


Assuntos
Ácido Clavulânico/administração & dosagem , Transtornos Relacionados ao Uso de Cocaína/tratamento farmacológico , Transportador 2 de Aminoácido Excitatório/genética , Animais , Cocaína/administração & dosagem , Cocaína/efeitos adversos , Transtornos Relacionados ao Uso de Cocaína/genética , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Transportador 2 de Aminoácido Excitatório/metabolismo , Glutamatos/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Autoadministração
8.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 5): o738, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23723889

RESUMO

Three independent mol-ecules comprise the asymmetric unit of the title compound, C8H9NO2, in which the dihedral angles between the amide group and the benzene ring are 3.0 (2), 4.0 (3) and 3.3 (9)°. In the crystal, O-H⋯O hydrogen bonds and weak C-H⋯N inter-actions are observed, forming infinite chains along [101].

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