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排序方式: 共有187条查询结果,搜索用时 15 毫秒
101.
Run Yu Junning Cai PingSun Leung 《Aquaculture Economics & Management (Blackwell Science)》2013,17(4):225-251
This paper develops a systematic approach for the assessment of export performance and applies it to evaluate the major shrimp exporters for the U.S. market during the period from 1991 to 2007. Export performance is evaluated from two perspectives: (1) an individual exporter's competitiveness in a specific shrimp product in terms of comparative advantage, and (2) an individual exporter's overall competitiveness in the U.S. market in terms of specialization. 相似文献
102.
Effects of Pomegranate Juice Supplementation on Pulse Wave Velocity and Blood Pressure in Healthy Young and Middle-aged Men and Women 总被引:2,自引:2,他引:0
Lynn A Hamadeh H Leung WC Russell JM Barker ME 《Plant foods for human nutrition (Dordrecht, Netherlands)》2012,67(3):309-314
Pomegranate juice may improve cardiovascular risk because of its content of antioxidant polyphenols. We conducted a randomized placebo-controlled parallel study to examine the effect of pomegranate juice on pulse wave velocity (PWV), blood pressure (BP) and plasma antioxidant status (ferric reducing power; FRAP) in 51 healthy adults (30-50?years). Participants consumed 330?ml/day of pomegranate juice or control drink for four?weeks. Measurements were made at baseline and at four?weeks. There was no effect of the intervention on PWV (P?=?0.694) and plasma FRAP (P?=?0.700). However, there was a significant fall in systolic blood pressure (-3.14?mmHg, P?0.001), diastolic blood pressure (-2.33?mmHg P?0.001) and mean arterial pressure (-2.60?mmHg, P?0.001). Change in weight was similar in the two groups over the intervention period (P?=?0.379). The fall in BP was not paralleled by changes in concentration of serum angiotensin converting enzyme. We conclude that pomegranate juice supplementation has benefits for BP in the short term, but has no effect on PWV. The mechanism for the effect is uncertain. 相似文献
103.
Geoffrey Jones Joyce Leung Hugh Robertson 《Journal of Agricultural, Biological & Environmental Statistics》2009,14(1):66-78
We introduce a new method for modeling a population of growth curves with B-splines, adapting the usual regression spline basis to ensure a horizontal upper asymptote in all fitted curves. The new
method is easily implemented in standard statistical software. We motivate and illustrate our method using data on the growth
of Brown Kiwi (Apteryx mantelli) in the North Island of New Zealand, including a time-dependent covariate to investigate the effects of different rearing
environments on patterns of weight increase. 相似文献
104.
Michaeli D Martin GR Kettman J Benjamini E Leung DY Blatt BA 《Science (New York, N.Y.)》1969,166(3912):1522-1524
After being injected with collagen from rat or guinea pig skin, rabbits form high titer, species-specific antibodies to collagen. Antibody is directed primarily against the alpha2 chain of collagen with little reaction with the alpha1 chain. The amino terminal peptide of cyanogen bromide cleavage of the alpha2 chain of guinea pig skin collagen, alpha2-CBl, effectively inhibited the antigen-antibody reaction, an indication that a major antigenic determinant of collagen is located at the amino terminal of the alpha2 chain. 相似文献
105.
106.
P. J. Bergman † M. A. CampsPalau J. A. McKnight N. F. Leibman C. A. Novosad S. Brenn S. N. Ettinger M. M. Endicott K. Finora D. Craft C. Leung J. Liao I. Riviere A. E. Hohenhaus A. Houghton M. Perales J. D. Wolchok 《Veterinary and comparative oncology》2005,3(1):35-36
Introduction: Canine malignant melanoma (CMM) is an aggressive neoplasm treated with surgery and/or fractionated RT; however, metastatic disease is common and chemoresistant. Preclinical and clinical studies by our laboratory and others have shown that xenogeneic DNA vaccination with tyrosinase family members can produce immune responses resulting in tumor rejection or protection and prolongation of survival. The potency of DNA vaccines can be further enhanced by adding DNA encoding cytokine genes. We have shown in preclinical mouse models that GM‐CSF DNA enhances immune responses and tumor protection. These studies provided the impetus for murine tyrosinase (muTyr) ± human GM‐CSF (huGM‐CSF) DNA vaccination in CMM.
Materials & Methods: Two groups of five dogs each with advanced (WHO stage II‐IV) CMM received four biweekly IM injections (100 ug or 500 ug, respectively/vaccination) of plasmid DNA encoding muTyr via the Biojector2000 jet delivery device. Subsequently, three groups of nine dogs each with advanced CMM received four biweekly IM injections of plasmid DNA encoding muTyr (50 ug), huGM‐CSF (3 dogs each at 100/400/800 ug) or both.
Results: Minimal to mild pain was noted on vaccination and no toxicity or induction of autoimmunity was seen. The KM median survival time was 224 days (100/500 ug muTyr), 278 days (50 ug muTyr), 140 days (huGM‐CSF) and >265 days (muTyr & huGM‐CSF; 6 dogs still alive).
Conclusions: The results of these trials demonstrate that xenogeneic DNA vaccination continues to be a safe and potentially therapeutic modality for CMM. These results also warrant further evaluation of this novel therapeutic in a Phase II setting. 相似文献
Materials & Methods: Two groups of five dogs each with advanced (WHO stage II‐IV) CMM received four biweekly IM injections (100 ug or 500 ug, respectively/vaccination) of plasmid DNA encoding muTyr via the Biojector2000 jet delivery device. Subsequently, three groups of nine dogs each with advanced CMM received four biweekly IM injections of plasmid DNA encoding muTyr (50 ug), huGM‐CSF (3 dogs each at 100/400/800 ug) or both.
Results: Minimal to mild pain was noted on vaccination and no toxicity or induction of autoimmunity was seen. The KM median survival time was 224 days (100/500 ug muTyr), 278 days (50 ug muTyr), 140 days (huGM‐CSF) and >265 days (muTyr & huGM‐CSF; 6 dogs still alive).
Conclusions: The results of these trials demonstrate that xenogeneic DNA vaccination continues to be a safe and potentially therapeutic modality for CMM. These results also warrant further evaluation of this novel therapeutic in a Phase II setting. 相似文献
107.
TH Jones LJ Thompson JH Lawton TM Bezemer RD Bardgett TM Blackburn KD Bruce PF Cannon GS Hall SE Hartley G Howson CG Jones C Kampichler E Kandeler DA Ritchie 《Science (New York, N.Y.)》1998,280(5362):441-443
In model terrestrial ecosystems maintained for three plant generations at elevated concentrations of atmospheric carbon dioxide, increases in photosynthetically fixed carbon were allocated below ground, raising concentrations of dissolved organic carbon in soil. These effects were then transmitted up the decomposer food chain. Soil microbial biomass was unaffected, but the composition of soil fungal species changed, with increases in rates of cellulose decomposition. There were also changes in the abundance and species composition of Collembola, fungal-feeding arthropods. These results have implications for long-term feedback processes in soil ecosystems that are subject to rising global atmospheric carbon dioxide concentrations. 相似文献
108.
T Fujisawa TH Oosterkamp van der Wiel WG BW Broer R Aguado S Tarucha LP Kouwenhoven 《Science (New York, N.Y.)》1998,282(5390):932-935
A double quantum dot device is a tunable two-level system for electronic energy states. A dc electron current was used to directly measure the rates for elastic and inelastic transitions between the two levels. For inelastic transitions, energy is exchanged with bosonic degrees of freedom in the environment. The inelastic transition rates are well described by the Einstein coefficients, relating absorption with stimulated and spontaneous emission. The most effectively coupled bosons in the specific environment of the semiconductor device used here were acoustic phonons. The experiments demonstrate the importance of vacuum fluctuations in the environment for quantum dot devices and potential design constraints for their use for preparing long-lived quantum states. 相似文献
109.
Peng Y Ma C Li Y Leung KS Jiang ZH Zhao Z 《Plant foods for human nutrition (Dordrecht, Netherlands)》2005,60(4):161-164
An HPLC-DAD method has been developed to quantitatively analyze for the content of zeaxanthin dipalmitate, a major carotenoid
in Fructus Lycii, in different species of the genus Lycium. Determination was performed using an Alltima C18 column with the mobile phase consisting of acetonitrile and dichloromethane
(42:58). The total contents of carotenoids in these samples were also determined by using UV spectrophotometric assay. Total
carotenoid concentrations of different Fructus Lycii are within the range of 0.03–0.5%. Zeaxanthin dipalmitate is a predominant
carotenoid, comprising 31–56% of the total carotenoids in Fructus Lycii. This study is the first systematic quantification
of the carotenoids in the fruits of different Lycium species. The results demonstrated that these methods are reliable and facile techniques for rapid analysis of carotenoids
for crude drug and plant-derived food supplements. 相似文献
110.
籼稻品种三黄占2号的稻瘟病持久抗性评价与遗传分析 总被引:13,自引:0,他引:13
籼稻三黄占2号在生产上种植10多年,表现了稳定持久的稻瘟病抗性。接种及多点田间试验结果表明,三黄占2号不仅对中国稻瘟病菌株有广谱抗性,而且对菲律宾稻瘟病菌株亦有高的抗性频率(98%)。在国际稻瘟病圃(IRBN)其叶瘟及穗瘟抗性相当或好于持久抗性品种OS6、Moroberekan和IR36。三黄占2号感病后,亦显示出高水平稻瘟病数量抗性。分析由三黄占2号与丽江新团黑谷杂交构建的重组自交系分离群体的抗病性,发现三黄占2号稻瘟病质量抗性是由多个主效基因控制的,其稻瘟病数量抗性是非小种专一的。应用候选抗性基因方法鉴 相似文献