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1.
Sci Rep ; 14(1): 9400, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658673

RESUMO

Maintaining a power balance between generation and demand is generally acknowledged as being essential to maintaining a system frequency within reasonable bounds. This is especially important for linked renewable-based hybrid power systems (HPS), where disruptions are more likely to occur. This paper suggests a prominent modified "Fractional order-proportional-integral with double derivative (FOPIDD2) controller" as an innovative HPS controller in order to navigate these obstacles. The recommended control approach has been validated in power systems including wind, reheat thermal, solar, and hydro generating, as well as capacitive energy storage and electric vehicle. The improved controller's performance is evaluated by comparing it to regular FOPID, PID, and PIDD2 controllers. Furthermore, the gains of the newly structured FOPIDD2 controller are optimized using a newly intended algorithm terms as squid game optimizer (SGO). The controller's performance is compared to benchmarks such as the grey wolf optimizer (GWO) and jellyfish search optimization. By comparing performance characteristics such as maximum frequency undershoot/overshoot, and steadying time, the SGO-FOPIDD2 controller outperforms the other techniques. The suggested SGO optimized FOPIDD2 controller was analyzed and validated for its ability to withstand the influence of power system parameter uncertainties under various loading scenarios and situations. Without any complicated design, the results show that the new controller can work steadily and regulate frequency with an appropriate controller coefficient.

2.
Polymers (Basel) ; 15(22)2023 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-38006111

RESUMO

Significant progress has been made in the advancement of perovskite solar cells, but their commercialization remains hindered by their lead-based toxicity. Many non-toxic perovskite-based solar cells have demonstrated potential, such as Cs2AgBi0.75Sb0.25Br6, but their power conversion efficiency is inadequate. To address this issue, some researchers are focusing on emerging acceptor-donor-acceptor'-donor-acceptor (A-DA'D-A)-type non-fullerene acceptors (NFAs) for Cs2AgBi0.75Sb0.25Br6 to find effective electron transport layers for high-performance photovoltaic responses with low voltage drops. In this comparative study, four novel A-DA'D-A-type NFAs, BT-LIC, BT-BIC, BT-L4F, and BT-BO-L4F, were used as electron transport layers (ETLs) for the proposed devices, FTO/PEDOT:PSS/Cs2AgBi0.75Sb0.25Br6/ETL/Au. Comprehensive simulations were conducted to optimize the devices. The simulations showed that all optimized devices exhibit photovoltaic responses, with the BT-BIC device having the highest power conversion efficiency (13.2%) and the BT-LIC device having the lowest (6.8%). The BT-BIC as an ETL provides fewer interfacial traps and better band alignment, enabling greater open-circuit voltage for efficient photovoltaic responses.

3.
Sci Rep ; 13(1): 20121, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978337

RESUMO

The objective of this study is to enhance the effectiveness of anticorrosive coatings applied to steel pipelines utilized for the transportation of petroleum products. However, these pipelines are susceptible to corrosion, necessitating the implementation of an economically viable protection system. Therefore, this research endeavors to introduce a novel pigment consisting of titanium dioxide/zinc oxide (TiO2/ZnO) core-shell structure. The pigment is designed to be incorporated into polymeric coating formulations and subsequently subjected to standard testing methods, including immersion tests, adhesion assessments, and electrochemical measurements. The pigment was synthesized and characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), and electron microscopy (SEM and TEM). Electrochemical impedance spectroscopy (EIS) was hired for observing the resistance and capacitance of the formulated coatings through immersion in corrosive medium (3.5% NaCl). The obtained results conveyed that the prepared core-shell pigment with its unique structure had strongly elevated the resistivity of the formulated coating, which enhanced its role in the protection of the pipeline wall from corrosion.

4.
Nanomaterials (Basel) ; 13(9)2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-37177069

RESUMO

In recent years, lead-based perovskites solar cells have demonstrated excellent power-conversion efficiency. Despite their remarkable progress, the commercialization of lead-based perovskites is hampered by lead toxicity concerns. The recently discovered non-toxic FACsSnI3 perovskite has the potential to replace lead-based perovskites in solar cell applications. Since the perovskite material FACsSnI3 (FA0.85Cs0.15SnI3) is relatively new, there is a lack of information, particularly regarding the design features required for electron and hole-transport layers for efficient photovoltaic responses. The important variables, such as electron affinity, energy band gap, film thickness, and doping density of both electron and hole-transport layers, were simulated and modeled separately and iteratively in this study to achieve the most efficient photovoltaic response. Finally, the absorber layer thickness of FACsSnI3 perovskite is tuned to achieve a maximum power-conversion efficiency of slightly more than 24%. We hope that the findings of this study will serve as a strong guideline for future research and the design of lead-free perovskite solar cells for efficient photovoltaic responses.

5.
Polymers (Basel) ; 14(17)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36080688

RESUMO

Bulk-heterojunction (BHJ) polymer solar cells have received a great deal of attention mainly due to the possibility of higher power conversion efficiency for photovoltaic applications. Therefore, in this study, relatively novel polymer BHJ solar cells are proposed (ITO/ETL/PTB7:PC70BM/PEDOT:PSS/Au) with various electron transport layers (ETL) such as zinc oxysulfide (Zn(O,S)), zinc selenide (ZnSe), and poly[(9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] dibromide (PFN-Br). Here, each ETL material is selected based on the energy bandgap compatibility with ITO as well as the PTB7:PC70BM active layer and is based on other physical properties, which are generally required for efficient photovoltaic responses. Each proposed device is comprehensively optimized and then photovoltaic responses are simulated and compared using the software SCAPS-1D. It was observed that the ITO/Zn(O,S)/PTB7:PC70BM/PEDOT:PSS/Au device offered the highest power-conversion efficiency of up to 17.15% with an open-circuit voltage of 0.85 volts, a short-circuit current of 28.23 mA/cm2, and a fill factor of 70.69%.

6.
Polymers (Basel) ; 14(5)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35267712

RESUMO

Polymer semiconductors may have the potential to fully replace silicon in next-generation solar cells because of their advantages such as cheap cost, lightweight, flexibility, and the ability to be processed for very large area applications. Despite these advantages, polymer solar cells are still facing a certain lack of power-conversion efficiency (PCE), which is essentially required for commercialization. Recently, bulk heterojunction of PTB7:PC70BM as an active layer showed remarkable performance for polymer solar cells in terms of PCE. Thus, in this paper, we developed and optimized a novel design using PEDOT:PSS and PFN-Br as electron and hole transport layers (ETL and HTL) for ITO/PEDOT:PSS/PT7B:PC70BM/PFN-Br/Ag as a polymer solar cell, with the help of simulation. The optimized solar cell has a short-circuit current (Isc) of 16.434 mA.cm-2, an open-circuit voltage (Voc) of 0.731 volts, and a fill-factor of 68.055%, resulting in a maximum PCE of slightly above 8%. The findings of this work may contribute to the advancement of efficient bulk-heterojunction-based polymer solar cells.

7.
Polymers (Basel) ; 13(13)2021 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-34198983

RESUMO

Halide based perovskite offers numerous advantages such as high-efficiency, low-cost, and simple fabrication for flexible solar cells. However, long-term stability as well as environmentally green lead-free applications are the real challenges for their commercialization. Generally, the best reported perovskite solar cells are composed of toxic lead (Pb) and unstable polymer as the absorber and electron/hole-transport layer, respectively. Therefore, in this study, we proposed and simulated the photovoltaic responses of lead-free absorber such as cesium titanium (IV) bromide, Cs2TiBr6 with dopant free electron phenyl-C61-butyric acid methyl ester (PCBM), and dopant free hole transport layer N,N'-Di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) for the Ag/BCP/PCBM/Cs2TiBr6/NPB/ITO based perovskite solar cell. After comprehensive optimization of each layer through vigorous simulations with the help of software SCAPS 1D, it is observed that the proposed solar cell can yield maximum power-conversion efficiency up to 16.85%. This efficiency is slightly better than the previously reported power-conversion efficiency of a similar type of perovskite solar cell. We believe that the outcome of this study will not only improve our knowledge, but also triggers further investigation for the dopant and lead-free perovskite solar cell.

8.
Polymers (Basel) ; 13(10)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063395

RESUMO

Generally, polymer-based memory devices store information in a manner distinct from that of silicon-based memory devices. Conventional silicon memory devices store charges as either zero or one for digital information, whereas most polymers store charges by the switching of electrical resistance. For the first time, this study reports that the novel conducting polymer Poly-N-Epoxy-Propyl Carbazole (PEPC) can offer effective memory storage behavior. In the current research, the electrical characterization of a single layer memory device (metal/polymer/metal) using PEPC, with or without doping of charge transfer complexes 7,7,8,8-tetra-cyanoquino-dimethane (TCNQ), was investigated. From the current-voltage characteristics, it was found that PEPC shows memory switching effects in both cases (with or without the TCNQ complex). However, in the presence of TCNQ, the PEPC performs faster memory switching at relatively lower voltage and, therefore, a higher ON and OFF ratio (ION/IOFF ~ 100) was observed. The outcome of this study may help to further understand the memory switching effects of conducting polymer.

9.
Toxicol Sci ; 158(2): 286-301, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28482088

RESUMO

Diabetes mellitus risk is increased by prolonged usage of antidepressants (ADs). Although various mechanisms are suggested for their diabetogenic potential, whether a direct effect of ADs on pancreatic ß-cells is involved is unclear. We examined this idea for 3 ADs: paroxetine, clomipramine and, with particular emphasis, fluoxetine, on insulin secretion, mitochondrial function, cellular bioenergetics, KATP channel activity, and caspase activity in murine and human cell-line models of pancreatic ß-cells. Metabolic assays showed that these ADs decreased the redox, oxidative respiration, and energetic potential of ß-cells in a time and concentration dependent manner, even at a concentration of 100 nM, well within the therapeutic window. These effects were related to inhibition of mitochondrial complex I and III. Consistent with impaired mitochondrial function, lactate output was increased and insulin secretion decreased. Neither fluoxetine, antimycin nor rotenone could reactivate KATP channel activity blocked by glucose unlike the mitochondrial uncoupler, FCCP. Chronic, but not acute, AD increased oxidative stress and activated caspases, 3, 8, and 9. A close agreement was found for the rates of oxidative respiration, lactate output and modulation of KATP channel activity in MIN6 cells with those of primary murine cells; data that supports MIN6 as a valid model to study beta-cell bioenergetics. To conclude, paroxetine, clomipramine and fluoxetine were all cytotoxic at therapeutic concentrations on pancreatic beta-cells; an action suggested to arise by inhibition of mitochondrial bioenergetics, oxidative stress and induction of apoptosis. These actions help explain the diabetogenic potential of these ADs in humans.


Assuntos
Antidepressivos/uso terapêutico , Ilhotas Pancreáticas/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Animais , Antidepressivos/farmacologia , Ilhotas Pancreáticas/fisiologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Técnicas de Patch-Clamp
10.
J Egypt Soc Parasitol ; 46(1): 49-55, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27363040

RESUMO

Toxoplasmosis caused by Toxoplasma gondii is one of the most prevalent parasitic diseases in human beings. Human toxoplasmosis can be associated with serious clinical manifestations, particularly in developing fetus. The aim of the current study was to identify the possible lineage type of Toxoplasma gondii, molecularly detected in placental samples of women whose pregnancies were spontaneously terminated in the first trimester. Preliminary detection of Toxoplasma genomic materials was done by a SYBR green qPCR technology. Subsequent identification of Toxoplasma strain was done for the positive samples using PCR-restriction fragment length polymorphism (RFLP) at the SAG2 loci of T. gondii using restriction enzymes HhaI and Sau3AI. Out of 72 tested samples, Toxoplasma B1 gene was detected in 9 cases. Toxoplasma genotypes I and II in addition to unknown type were identified in 4, 3 and 2 cases respectively, while type III was not detected in our samples, hence excluded as a leading cause of abortion in humans in our preliminary study. Nevertheless, it remains uncertain to what extent the genotype of the parasite directly contributes to the clinical severity of human toxoplasmosis. Certainly, advanced molecular techniques targeting different Toxoplasma strains are crucial for better understanding of human toxoplasmosis. For more elucidation, additional studies are recommended intended for genetic characterization of such serious parasitic infection using larger number of samples.


Assuntos
Aborto Espontâneo/parasitologia , Variação Genética , Complicações Parasitárias na Gravidez/parasitologia , Toxoplasma/genética , Toxoplasmose/parasitologia , Aborto Espontâneo/epidemiologia , Adulto , Feminino , Genótipo , Humanos , Gravidez , Complicações Parasitárias na Gravidez/epidemiologia , Toxoplasmose/complicações
11.
Prostate Cancer Prostatic Dis ; 19(2): 168-73, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26754261

RESUMO

BACKGROUND: Magnetic resonance imaging (MRI) is emerging as a robust, noninvasive method for detecting and characterizing prostate cancer (PCa), but limitations remain in its ability to distinguish cancerous from non-cancerous tissue. We evaluated the performance of a novel MRI technique, restriction spectrum imaging (RSI-MRI), to quantitatively detect and grade PCa compared with current standard-of-care MRI. METHODS: In a retrospective evaluation of 33 patients with biopsy-proven PCa who underwent RSI-MRI and standard MRI before radical prostatectomy, receiver-operating characteristic (ROC) curves were performed for RSI-MRI and each quantitative MRI term, with area under the ROC curve (AUC) used to compare each term's ability to differentiate between PCa and normal prostate. Spearman rank-order correlations were performed to assess each term's ability to predict PCa grade in the radical prostatectomy specimens. RESULTS: RSI-MRI demonstrated superior differentiation of PCa from normal tissue, with AUC of 0.94 and 0.85 for RSI-MRI and conventional diffusion MRI, respectively (P=0.04). RSI-MRI also demonstrated superior performance in predicting PCa aggressiveness, with Spearman rank-order correlation coefficients of 0.53 (P=0.002) and -0.42 (P=0.01) for RSI-MRI and conventional diffusion MRI, respectively, with tumor grade. CONCLUSIONS: RSI-MRI significantly improves upon current noninvasive PCa imaging and may potentially enhance its diagnosis and characterization.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Idoso , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias da Próstata/cirurgia , Curva ROC , Estudos Retrospectivos , Carga Tumoral
12.
Eur J Med Chem ; 69: 591-600, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24095752

RESUMO

A series of 6-aryl-5-cyano thiouracil derivatives (2a-c to 11a-c) was synthesized from 6-aryl-4-hydrazino-2-thioxo-1,2-dihydropyrimidine-5-carbonitriles (1a-c). The products were characterized by analytical and spectral data (IR, (1)H NMR, (13)C NMR and mass spectra). All compounds were screened for their in-vitro antibacterial and antifungal activities. Compounds 7a, 7g and 9a-c showed pronounced antimicrobial activity than standards. Some of the newly synthesized compounds were evaluated for antioxidant activity. Compounds 1c, 5c and 8c displayed promising free radical scavenging activity and found to be more potent than standard, ascorbic acid (vitamin C).


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Tiouracila/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Antioxidantes/síntese química , Antioxidantes/química , Compostos de Bifenilo/química , Relação Dose-Resposta a Droga , Sequestradores de Radicais Livres/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Picratos/química , Relação Estrutura-Atividade , Tiouracila/síntese química , Tiouracila/química
14.
Australas Radiol ; 45(1): 71-3, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11259979

RESUMO

A patient with nasopharyngeal carcinoma developed clubbing and hypertrophic osteoarthropathy 6 months before radiological detection of secondary deposits in the lung. Another patient with nasopharyngeal carcinoma developed digital clubbing and hypertrophic osteoarthropathy 6 months after the discovery of lung metastases. Development of a paraneoplastic syndrome in the form of hypertrophic osteoarthropathy and digital clubbing is very rare. This manifestation of nasopharyngeal cancers is presented, with a short review of its biology and pathogenesis.


Assuntos
Neoplasias Nasofaríngeas/complicações , Osteoartropatia Hipertrófica Secundária/diagnóstico , Osteoartropatia Hipertrófica Secundária/etiologia , Adulto , Terapia Combinada , Humanos , Neoplasias Pulmonares/secundário , Masculino , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/terapia , Osteoartropatia Hipertrófica Secundária/tratamento farmacológico
15.
J Clin Periodontol ; 20(8): 595-600, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8408722

RESUMO

Previous studies have demonstrated that accurate alveolar bone-level measurements can be made using digitally enhanced bitewing radiographs. In this study, we determined the effect of exposure variations on bone-level measurement accuracy using digital radiographic images of dry skulls. 6 direct bone-level measurements on the mandibular 1st molars of dry skulls were established by consensus of 2 expert observers. 13 bitewing radiographs were taken on each side of 11 skulls, using a specially designed positioning device. Exposure settings of 70 kVp, 10 mA, and 24 impulses were empirically chosen as the baseline. Kilovoltage and impulses times were individually varied (50 to 100 kVp in 10 kV increments and 15 to 48 impulses in 6 steps) to ensure a wide range of clinically relevant optical densities on the test images. The radiographs were digitized and alveolar bone level measurements, corresponding to those for skulls, were made on the images by 2 observers. Pearson product-moment coefficients between radiographs and criteria measurements were calculated. It was found that dry skull and digital bitewing radiographic measurements were highly correlated, within the limits of exposure parameter variations tested. Accurate measurements of alveolar bone level are possible from bitewing radiographs taken within a wide range of exposures, when digital image processing techniques are employed.


Assuntos
Absorciometria de Fóton , Processo Alveolar/diagnóstico por imagem , Cefalometria , Intensificação de Imagem Radiográfica , Adulto , Perda do Osso Alveolar/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Radiografia Interproximal , Dente/diagnóstico por imagem
16.
Jpn J Exp Med ; 46(1): 1-6, 1976 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-933365

RESUMO

Investigating the effects of Li and Rb on the toxicity of digoxin and ouabain revealed Li to be a potentiator while Rb to be a protector. The effects of Rb in this respect are, more or less, qualitatively comparable to those of K; the intensity of Rb effects is more than that of K. In case of digoxin the effect produced from the combined use of both Rb and K is more than each individual effect. With ouabain, however, whereas Rb offered protection K failed to do so. Electrolyte changes in cardiac tissue showed that Li increased the tissue content of Ca while Rb produced the opposite effect. In comparing Rb with K, both increased the K level in the cardiac muscle. However, in the case of ouabain the infusion of K failed to decrease the Ca level and this might explain its failure to protect against ouabain toxicity. This points to the importance of Ca, rather than K, in controlling the excitability of the cardiac muscle and in effecting the toxicity of cardiac glycosides. Evidences presented indicate the superiority of Rb over K and propose its trial in clinical practice.


Assuntos
Digoxina/toxicidade , Lítio/farmacologia , Rubídio/farmacologia , Animais , Glicosídeos Digitálicos/sangue , Digoxina/antagonistas & inibidores , Sinergismo Farmacológico , Eletrólitos/metabolismo , Feminino , Cobaias , Dose Letal Mediana , Masculino , Miocárdio/metabolismo , Ouabaína/toxicidade , Potássio/farmacologia
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