Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Macromol Rapid Commun ; : e2400275, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38830087

RESUMO

The advent of nonfullerene acceptors (NFAs) has greatly improved the photovoltaic performance of organic solar cells (OSCs). However, to compete with other solar cell technologies, there is a pressing need for accelerated research and development of improved NFAs as well as their compatible wide bandgap polymer donors. In this study, a novel electron-withdrawing building block, succinimide-substituted thiophene (TS), is utilized for the first time to synthesize three wide bandgap polymer donors: PBDT-TS-C5, PBDT-TSBT-C12, and PBDTF-TSBT-C16. These polymers exhibit complementary bandgaps for efficient sunlight harvesting and suitable frontier energy levels for exciton dissociation when paired with the extensively studied NFA, Y6. Among these donors, PBDTF-TSBT-C16 demonstrates the highest hole mobility and a relatively low highest occupied molecular orbital (HOMO) energy level, attributed to the incorporation of thiophene spacers and electron-withdrawing fluorine substituents. OSC devices based on the blend of PBDTF-TSBT-C16:Y6 achieve the highest power conversion efficiency of 13.21%, with a short circuit current density (Jsc) of 26.83 mA cm-2, an open circuit voltage (Voc) of 0.80 V, and a fill factor of 0.62. Notably, the Voc × Jsc product reaches 21.46 mW cm-2, demonstrating the potential of TS as an electron acceptor building block for the development of high-performance wide bandgap polymer donors in OSCs.

2.
Animals (Basel) ; 13(21)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37958108

RESUMO

Weed encroachment on grasslands can negatively affect herbage allowance and animal behavior, impacting livestock production. We used low-cost GPS collars fitted to twenty-four Angus crossbred steers to evaluate the effects of different levels of weed encroachment on animal activities and spatial distribution. The experiment was established with a randomized complete block design, with three treatments and four blocks. The treatments were paddocks free of weeds (weed-free), paddocks with weeds established in alternated strips (weed-strips), and paddocks with weeds spread throughout the entire area (weed-infested). Animals in weed-infested paddocks had reduced resting time and increased grazing time, distance traveled, and rate of travel (p < 0.05) compared to animals in weed-free paddocks. The spatial distribution of the animals was consistently greater in weed-free paddocks than in weed-strips or weed-infested areas. The effects of weed encroachment on animal activities were minimized after weed senescence at the end of the growing season. Pasture weed encroachment affected cattle behavior and their spatial distribution across the pasture, potentially impacting animal welfare. Further long-term studies are encouraged to evaluate the impacts of weed encroachment on animal performance and to quantify the effects of behavioral changes on animal energy balance.

3.
World Neurosurg ; 159: e32-e39, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34861449

RESUMO

OBJECTIVE: Minimally invasive surgery (MIS) techniques have advanced the treatment of metastatic diseases to the spine. The objective of this review is to describe clinical outcomes, benefits, and complications of these techniques. METHODS: All relevant clinical studies describing the role of MIS, computer-assisted navigation (CAN), robot-assisted (RA) procedures, and laser interstitial thermal therapy (LITT) in the treatment of metastatic spine diseases were identified from PubMed, MEDLINE, and relevant article bibliographies. RESULTS: For MIS articles, we filtered 1480 results and identified 26 studies. For CAN, we searched 464 articles to identify 18 articles for review. For RA, we searched 321 results to identify 7 studies for review. For LITT, we identified 21 articles for review. CONCLUSIONS: MIS for the treatment of spine metastasis has significant potential benefits in reducing surgical site infections, hospital stay, and blood loss without compromising instrument accuracy or overall outcomes. Overall, MIS and its adjuncts have the potential to reduce the risks involved in the treatment of patients with metastatic disease to the spinal column without compromising the benefits of decompression and stabilization of the spine.


Assuntos
Fusão Vertebral , Neoplasias da Coluna Vertebral , Humanos , Tempo de Internação , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Estudos Retrospectivos , Fusão Vertebral/métodos , Neoplasias da Coluna Vertebral/etiologia , Neoplasias da Coluna Vertebral/cirurgia , Coluna Vertebral/cirurgia , Resultado do Tratamento
4.
Emerg Top Life Sci ; 5(2): 337-347, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-33973632

RESUMO

Integrating perennial groundcovers (PGC) - sometimes referred to as living mulches or perennial cover crops - into annual cash-crop systems could address root causes of bare-soil practices that lead to negative impacts on soil and water quality. Perennial groundcovers bring otherwise absent functional traits - namely perenniality - into cash-crop systems to preserve soil and regenerate water, carbon, and nutrient cycles. However, if not optimized, they can also cause competitive interactions and yield loss. When designing PGC systems, the goal is to maximize complementarity - spatial and temporal separation of growth and resource acquisition - between PGC and cash crops through both breeding and management. Traits of interest include complementary root and shoot systems, reduced shade avoidance response in the cash-crop, and PGC summer dormancy. Successful deployment of PGC systems could increase both productivity and profitability by improving water- and nutrient-use-efficiency, improving weed and pest control, and creating additional value-added opportunities like stover harvest. Many scientific questions about the inherent interactions at the cell, plant, and ecosystem levels in PGC systems are waiting to be explored. Their answers could enable innovation and refinement of PGC system design for multiple geographies, crops, and food systems, creating a practical and scalable pathway towards resiliency, crop diversification, and sustainable intensification in agriculture.


Assuntos
Ecossistema , Solo , Agricultura , Melhoramento Vegetal , Tecnologia
5.
Ann Vasc Surg ; 66: 665.e1-665.e3, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31743783

RESUMO

Interval gangrene of the thigh is an extremely rare complication in vascular surgery. Most cases have reported interval gangrene of the calf as a consequence of a distal bypass procedure, with little documentation of interval thigh gangrene occurring after endovascular intervention. The present case suggests that in the process of placing multiple-level covered and bare metal stents in the iliac, superficial femoral, and popliteal arteries, interval gangrene of the thigh must be considered as a potential, albeit rare, complication. Preservation of pelvic and profunda femoris flow to the thigh is imperative to prevent the development of interval tissue loss. This case demonstrates the importance of maintaining profunda femoris circulation, especially in patients with significant vascular comorbidities. Patient consent was obtained for details of the case to be used for publication.


Assuntos
Procedimentos Endovasculares/efeitos adversos , Doença Iatrogênica , Doença Arterial Periférica/cirurgia , Complicações Pós-Operatórias/etiologia , Coxa da Perna/irrigação sanguínea , Coxa da Perna/patologia , Cicatrização , Idoso de 80 Anos ou mais , Implante de Prótese Vascular , Circulação Colateral , Procedimentos Endovasculares/instrumentação , Feminino , Gangrena , Humanos , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/fisiopatologia , Complicações Pós-Operatórias/patologia , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/cirurgia , Fluxo Sanguíneo Regional , Stents , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA