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排序方式: 共有1326条查询结果,搜索用时 15 毫秒
131.
During the last 15 years, reports, books, and published papers have demonstrated the positive health benefits of comprehensive health promotion and disease prevention interventions at the worksite. Although the progress made in worksite health promotion should not be understated, experts agree that it is time to step forward and address the new demands of the changing labor force. One area of intervention that needs to be more aggressively addressed is that of minority populations. Because work force projections show the high participation rate that Hispanics will have in the future labor force, the Hispanic population should be one of the targets of worksite health promotion. This paper reviews how employee health promotion programs have addressed Hispanic workers in the past and establishes directions for the future. 相似文献
132.
Opposing effects of quinacrine and chloroquine on the development of TA3 transplanted tumors in mice
Both quinacrine and chloroquine had been used as antimalarial agents. Furthermore, antineoplastic and antiviral effects have been described for quinacrine, while chloroquine has been described to induce viral replication and promote tumor growth. To search for differences in the growing rate of transplanted tumors, chloroquine or quinacrine were administered orally to AJ mice from 30 days previous to the inoculation of TA3 transplantable tumor cells, treatment being continued up to the end of the experiment. A control group, transplanted with tumor cells received tap drinking water. Marked differences between the three groups were found. Quinacrine had antitumoral effect, while chloroquine promoted a faster tumoral growth than controls. (p < 0.01). Results suggest caution in the use of chloroquine, because it might have a similar promoting effect on human neoplasia. 相似文献
133.
134.
Ali Mortezaei Marcelo Godoy Simões Fernando Pinhabel Marafão Josep M. Guerrero Ahmed Al Durra Tiago Davi Curi Busarello 《电力部件与系统》2017,45(8):864-880
This paper investigates selective sharing of load current components among the parallel operation of distributed generators (DGs) in three-phase four-wire stand-alone microgrids. The proposed control method is based on master-slave operation of DGs, and the goal of selective sharing of load current components is to have DGs located in close proximity of the load operating in slave mode, in order to inject their available energy and also compensate the non-active load current components, while the distant DGs might operate in master mode to share the remaining load autonomously. Droop control is employed due to impracticality of communication at remote nodes, and resistive line impedance compensation is adopted to decouple active and reactive power controllers and ensure proper active power sharing among master DGs, irrespective of the mitigation of non-active current components by the slave inverters. The sharing factors for each current component are determined by a higher level control. The Conservative Power Theory (CPT) decompositions provide decoupled power and current references for the inverters, resulting in a selective sharing strategy. The principles supporting the developed control strategy are discussed, and the effectiveness of the control is demonstrated through computational simulations using PSIM software. 相似文献
135.
J. E. Rodriguez‐Sanchez F. Perez‐Guerrero S. Liu A. Rodriguez‐Castellanos A. Albiter‐Hernandez 《Fatigue & Fracture of Engineering Materials & Structures》2014,37(6):637-644
A fatigue crack repair method for offshore jacket tubular joints is presented. This method is applicable for fatigue cracks detected and sized by regular inspection techniques such as magnetic particle inspection up to a crack depth in the range of 5 mm. The main advantage of the method relies on its easy implementation allowing to be applied immediately after the crack is detected because equipment required is easy to transport and operate; so, it can be on board of a regular inspection campaign ship. A welding procedure specification has to be prepared and qualified prior to implementation of the repair method, considering particular parameters of the jacket fleet and selecting the welding equipment to be used. The proposed method could reinstall the original fatigue life in early stages of growth avoiding the need of more expensive procedures of repair such as joint clamping. 相似文献
136.
Blake N. Johnson Karen Z. Lancaster Gehua Zhen Junyun He Maneesh K. Gupta Yong Lin Kong Esteban A. Engel Kellin D. Krick Alex Ju Fanben Meng Lynn W. Enquist Xiaofeng Jia Michael C. McAlpine 《Advanced functional materials》2015,25(39):6205-6217
A 3D printing methodology for the design, optimization, and fabrication of a custom nerve repair technology for the regeneration of complex peripheral nerve injuries containing bifurcating sensory and motor nerve pathways is introduced. The custom scaffolds are deterministically fabricated via a microextrusion printing principle using 3D models, which are reverse engineered from patient anatomies by 3D scanning. The bifurcating pathways are augmented with 3D printed biomimetic physical cues (microgrooves) and path‐specific biochemical cues (spatially controlled multicomponent gradients). In vitro studies reveal that 3D printed physical and biochemical cues provide axonal guidance and chemotractant/chemokinetic functionality. In vivo studies examining the regeneration of bifurcated injuries across a 10 mm complex nerve gap in rats showed that the 3D printed scaffolds achieved successful regeneration of complex nerve injuries, resulting in enhanced functional return of the regenerated nerve. This approach suggests the potential of 3D printing toward advancing tissue regeneration in terms of: (1) the customization of scaffold geometries to match inherent tissue anatomies; (2) the integration of biomanufacturing approaches with computational modeling for design, analysis, and optimization; and (3) the enhancement of device properties with spatially controlled physical and biochemical functionalities, all enabled by the same 3D printing process. 相似文献
137.
138.
Gómez-Barrena E Esteban J Molina-Manso D Adames H Martínez-Morlanes MJ Terriza A Yubero F Puértolas JA 《Journal of materials science. Materials in medicine》2011,22(7):1701-1706
Orthopaedic materials may improve its capacity to resist bacterial adherence, and subsequent infection. Our aim was to test
the bacterial adherence to alpha-tocopherol (frequently named vitamin E, VE) doped or blended UHMWPE with S. aureus and S. epidermidis, compared to virgin material. Collection strains and clinical strains isolated from patients with orthopaedic infections
were used, with the biofilm-developing ability as a covariable. While collection strains showed significantly less adherence
to VE-UHMWPE, some clinical strains failed to confirm this effect, leading to the conclusion that VE doped or blended UHMWPE
affects the adherence of some S. epidermidis and S. aureus strains, independently of the concentration in use, but the results showed important intraspecies differences and cannot
be generalized. 相似文献
139.
The purpose of our study was to develop suitable methods to quantify oxidative DNA lesions in the setting of transition metal-related diseases. Transition metal-driven Fenton reactions constitute an important endogenous source of reactive oxygen species (ROS). In genetic diseases with accumulation of transition metal ions, excessive ROS production causes pathophysiological changes, including DNA damage. Wilson's disease is an autosomal recessive disorder with copper toxicosis due to deficiency of ATP7B protein needed for excreting copper into bile. The Long-Evans Cinnamon (LEC) rat bears a deletion in Atp7b gene and serves as an excellent model for hepatic Wilson's disease. We used a sensitive capillary liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS/MS/MS) method in conjunction with the stable isotope-dilution technique to quantify several types of oxidative DNA lesions in the liver and brain of LEC rats. These lesions included 5-formyl-2'-deoxyuridine, 5-hydroxymethyl-2'-deoxyuridine, and the 5'R and 5'S diastereomers of 8,5'-cyclo-2'-deoxyguanosine and 8,5'-cyclo-2'-deoxyadenosine. Moreover, the levels of these DNA lesions in the liver and brain increased with age and correlated with age-dependent regulation of the expression of DNA repair genes in LEC rats. These results provide significant new knowledge for better understanding the implications of oxidative DNA lesions in transition metal-induced diseases, such as Wilson's disease, as well as in aging and aging-related pathological conditions. 相似文献
140.
Shuang?Liang Esteban?Broitman Yanan?Wang Anmin?Cao G?tz?VeserEmail author 《Journal of Materials Science》2011,46(9):2928-2937
Pure and mixed lanthanum and cerium oxides were synthesized via a reverse microemulsion-templated route. This approach yields
highly homogeneous and phase-stable mixed oxides with high surface areas across the entire range of La:Ce ratios from pure
lanthana to pure ceria. Surprisingly, all mixed oxides show the fluorite crystal structure of ceria, even for lanthanum contents
as high as 90%. Varying the La:Ce ratio not only allows tailoring of the oxide morphology (lattice parameter, pore structure,
particle size, and surface area), but also results in a fine-tuning of the reducibility of the oxide which can be explained
by the creation of oxygen vacancies in the ceria lattice upon La addition. Such finely controlled syntheses, which enable
the formation of stable, homogeneous mixed oxides across the entire composition range, open the path towards functional tailoring
of oxide materials, such as rational catalyst design via fine-tuning of redox activity. 相似文献