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1.
J Safety Res ; 88: 354-365, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38485378

RESUMO

INTRODUCTION: During the COVID-19 pandemic, public transport (e.g., bus and taxi) drivers encountered great stress because they needed to work to maintain the operation of the transportation system. This study proposes and empirically investigates the impacts of job stressors and economic stressors of public transport drivers on emotional exhaustion, and subsequent psychological well-being and performance under the health risk of COVID-19. The moderating effects of perceived threat and death anxiety on the relationships between stressors and emotional exhaustion are also examined. METHOD AND RESULTS: Using two survey samples collected from bus and taxi drivers in Taiwan, the results reveal that, except for the effect of time pressure on taxi drivers' exhaustion, job stressors (job overload and time pressure) and economic stressors (job insecurity) positively relate to emotional exhaustion for both bus and taxi drivers. Drivers' emotional exhaustion has negative effects on both job satisfaction and positive effects on risky driving behaviors. Perceived pandemic threat strengthens the positive influence of job insecurity on emotional exhaustion for bus drivers, while perceived pandemic threat and death anxiety weaken the negative influence of job insecurity on emotional exhaustion for taxi drivers. PRACTICAL APPLICATIONS: Effective intervention strategies and policies to mitigate perceived pandemic threat and death anxiety of drivers are recommended.


Assuntos
Condução de Veículo , COVID-19 , Humanos , Pandemias , COVID-19/epidemiologia , Inquéritos e Questionários , Satisfação no Emprego
2.
J Control Release ; 172(3): 1011-9, 2013 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-24095805

RESUMO

Drug delivery is essential to achieve effective therapy. Herein we report on the only implantable nanochannel membrane with geometrically defined channels as small as 2.5 nm that achieves constant drug delivery in vivo. Nanochannels passively control the release of molecules by physico-electrostatic confinement, thereby leading to constant drug diffusion. We utilize a novel design algorithm to select the optimal nanochannel size for each therapeutic agent. Using nanochannels as small as 3.6 and 20 nm, we achieve sustained and constant plasma levels of leuprolide, interferon α-2b, letrozole, Y-27632, octreotide, and human growth hormone, all delivered at clinically-relevant doses. The device was demonstrated in dogs, rats, and mice and was capable of sustaining target doses for up to 70 days. To provide evidence of therapeutic efficacy, we successfully combined nanochannel delivery with a RhoA pathway inhibitor to prevent chronic rejection of cardiac allografts in a rat model. Our results provide evidence that the nanochannel platform has the potential to dramatically improve long-term therapies for chronic conditions.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Nanoestruturas/ultraestrutura , Preparações Farmacêuticas/administração & dosagem , Animais , Cães , Desenho de Equipamento , Feminino , Humanos , Masculino , Membranas Artificiais , Camundongos , Nanoestruturas/química , Próteses e Implantes , Ratos , Ratos Sprague-Dawley
3.
Lab Chip ; 13(18): 3675-88, 2013 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-23884326

RESUMO

Despite the clinical success of pancreatic islet transplantation, graft function is frequently lost over time due to islet dispersion, lack of neovascularization, and loss of physiological architecture. To address these problems, islet encapsulation strategies including scaffolds and devices have been developed, which produced encouraging results in preclinical models. However, islet loss from such architectures could represent a significant limitation to clinical use. Here, we developed and characterized a novel islet encapsulation silicon device, the NanoGland, to overcome islet loss, while providing a physiological-like environment for long-term islet viability and revascularization. NanoGlands, microfabricated with a channel size ranging from 3.6 nm to 60 µm, were mathematically modeled to predict the kinetics of the response of encapsulated islets to glucose stimuli, based on different channel sizes, and to rationally select membranes for further testing. The model was validated in vitro using static and perifusion testing, during which insulin secretion and functionality were demonstrated for over 30-days. In vitro testing also showed 70-83% enhanced islet retention as compared to porous scaffolds, here simulated through a 200 µm channel membrane. Finally, evidence of in vivo viability of human islets subcutaneously transplanted within NanoGlands was shown in mice for over 120 days. In this context, mouse endothelial cell infiltration suggesting neovascularization from the host were identified in the retrieved grafts. The NanoGland represents a novel, promising approach for the autotransplantation of human islets.


Assuntos
Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/citologia , Nanoestruturas/química , Nanotecnologia/instrumentação , Animais , Movimento Celular , Difusão , Células Endoteliais , Glucose/farmacologia , Humanos , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Camundongos , Modelos Teóricos , Neovascularização Fisiológica , Silício/química , Transplante Heterólogo
4.
Anal Bioanal Chem ; 405(5): 1547-57, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23090650

RESUMO

Novel drug delivery systems capable of continuous sustained release of therapeutics have been studied extensively for use in the prevention and management of chronic diseases. The use of these systems holds promise as a means to achieve higher patient compliance while improving therapeutic index and reducing systemic toxicity. In this work, an implantable nanochannel drug delivery system (nDS) is characterized and evaluated for the long-term sustained release of atorvastatin (ATS) and trans-resveratrol (t-RES), compounds with a proven role in managing atherogenic dyslipidemia and promoting cardioprotection. The primary mediators of drug release in the nDS are nanofluidic membranes with hundreds of thousands of nanochannels (up to 100,000/mm(2)) that attain zero-order release kinetics by exploiting nanoconfinement and molecule-to-surface interactions that dominate diffusive transport at the nanoscale. These membranes were characterized using gas flow analysis, acetone diffusion, and scanning and transmission electron microscopy (SEM, TEM). The surface properties of the dielectric materials lining the nanochannels, SiO(2) and low-stress silicon nitride, were further investigated using surface charge analysis. Continuous, sustained in vitro release for both ATS and t-RES was established for durations exceeding 1 month. Finally, the influence of the membranes on cell viability was assessed using human microvascular endothelial cells. Morphology changes and adhesion to the surface were analyzed using SEM, while an MTT proliferation assay was used to determine the cell viability. The nanochannel delivery approach, here demonstrated in vitro, not only possesses all requirements for large-scale high-yield industrial fabrication, but also presents the key components for a rapid clinical translation as an implantable delivery system for the sustained administration of cardioprotectants.


Assuntos
Anticolesterolemiantes/administração & dosagem , Sistemas de Liberação de Medicamentos/instrumentação , Implantes de Medicamento/química , Ácidos Heptanoicos/administração & dosagem , Membranas Artificiais , Pirróis/administração & dosagem , Estilbenos/administração & dosagem , Vasodilatadores/administração & dosagem , Atorvastatina , Linhagem Celular , Sobrevivência Celular , Difusão , Desenho de Equipamento , Humanos , Nanoestruturas/química , Resveratrol
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