全文获取类型
收费全文 | 203篇 |
免费 | 17篇 |
专业分类
220篇 |
出版年
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 11篇 |
2014年 | 11篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 17篇 |
2010年 | 6篇 |
2009年 | 10篇 |
2008年 | 13篇 |
2007年 | 12篇 |
2006年 | 17篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有220条查询结果,搜索用时 15 毫秒
1.
2.
The effect of cooking on residues of the quinolones oxolinic acid and flumequine in fish was investigated. Salmon containing residues of oxolinic acid and flumequine was boiled or baked in the oven. Samples of raw and cooked muscle, skin, and bone, as well as of the water in which the fish was boiled and juice from the baked fish, were analysed. Oxolinic acid and flumequine did not degrade at the temperatures reached when cooking the fish. However, fish muscle free from drug residues may be contaminated during boiling and baking due to leakage of the drug from reservoirs in the fish. 相似文献
3.
Paraquat-resistant biotypes of the closely-related weed species Hordeum leporinum Link and H. glaucum Steud. are highly resistant to paraquat when grown during the normal winter growing season. However, when grown and treated with paraquat in summer, these biotypes are markedly less resistant to paraquat. This reduced resistance to paraquat in summer is primarily a result of increased temperature following herbicide treatment. The mechanism governing this decrease in resistance at high temperature was examined in H. leporinum. No differences were observed between susceptible and resistant biotypes in the interaction of paraquat with isolated thylakoids when assayed at 15, 25, or 35 °C. About 98 and 65% of applied paraquat was absorbed through the leaf cuticle of both biotypes at 15 and 30 °C, respectively. Following application to leaves, more herbicide was translocated in a basipetal direction in the susceptible biotype compared to the resistant biotype at 15 °C. However, at 30 °C more paraquat was translocated in a basipetal direction in the resistant biotype. Photosynthetic activity of young leaf tissue from within the leaf sheath which had not been directly exposed to paraquat was measured 24 h after treatment of plants with para. quat. This activity was inhibited in the susceptible biotype when plants were maintained at either 15 °C or 30 °C after treatment. In contrast, photosynthetic activity of such tissue of the resistant biotype was not inhibited when plants were maintained at 15 °C after treatment, but was inhibited at 30 °C. The mechanism of resistance in this biotype of H. leporinum correlates with decreased translocation of paraquat and decreased penetration to the active site. This mechanism is temperature sensitive and breaks down at higher temperatures.We are grateful to Zeneca Agrochemicals, Jealotts Hill, Berkshire, UK who provided [14C]paraquat. E.P. was supported through a Ph.D. scholarship from the Australian International Development Assistance Bureau and C.P. was the recipient of an Australian Research Council Postdoctoral Fellowship. 相似文献
4.
5.
Claudio Ioriatti Edison Pasqualini Alfeo Toniolli 《Experimental & applied acarology》1992,15(2):109-116
Laboratory studies using commercial formulations of mancozeb and dithianon at concentrations equivalent to recommended field rates of 200 and 80 g/hl, respectively, were conducted to evaluate toxic effects of these fungicides on the predatory miteAmblyseius andersoni Chant. In short-term tests where females were placed on apple-leaf disks and sprayed with mancozeb, no mortality of adults was observed; however, there was a 34% decrease in fecundity, a 7.1% decrease in egg hatch, and mortality of larvae and protonymphs was 6.7%. In long-term tests, a significant reduction in fecundity was also observed. A decrease in hatch that was dependent on age at time of treatment was found when eggs were treated directly with mancozeb. No effects on mite mortality or reproduction were observed in short-term tests with dithianon. These results suggest that dithianon might be considered as a potential alternative to mancozeb for scab control. 相似文献
6.
Native and exotic species of dioscorea used as food in brazil 总被引:1,自引:0,他引:1
The major reserve compounds of tubers (starch, soluble carbohydrates, proteins and non-soluble fibers) of five native Dioscorea species are analyzed with a view to their economic importance (for the staple food and pharmaceutical industries); distribution, phenology and germination are also investigated. Twenty-six native species and the cultivated edible exotics are listed, with phenological characteristics, popular name, habitat, popular medicinal importance and distribution. 相似文献
7.
Cecília Rodrigues Vieira Maria Carolina Blassioli Moraes Miguel Borges Edison Ryoiti Sujii Raúl Alberto Laumann 《Biological Control》2013,64(1):75-82
In many plants, the secondary metabolite cis-jasmone activates the metabolic pathway that produces volatile organic compounds attractive to natural enemies and, sometimes, repellent to herbivores. Previous studies indicate that the feeding damage caused by the herbivore Euschistus heros or the exogenous application of cis-jasmone in soybean plants induces the release of herbivore-induced plant volatiles (HIPVs) with a similar chemical profile and these compounds can attract the stink bug egg parasitoid Telenomus podisi (Scelionidae). Herein we tested in field conditions the effect of exogenous application of cis-jasmone in soybean plants on the parasitoid and stink bug community and on stink bug egg parasitism. In two areas, one within a soybean and another within a Crotalaria matrix, we randomly distributed 2 m2 plots, with soybean plants induced (treatment, n = 5) or not induced by cis-jasmone (control, n = 5) in the field. We sampled the parasitoid community weekly with yellow sticky traps (n = 3/plot) and monitored parasitism with sentinel eggs of E. heros (n = 150/plot). We also monitored the population of stink bugs weekly, by sampling each plot with shake-cloth technique. The abundance of Scelionidae was highest overall and also in treated plots during the first four weeks in the area with a soybean matrix, but decreased thereafter. The richness of parasitoid families was similar between treatment and control plots in the area with a soybean matrix, but higher in control plots in the area with a Crotalaria matrix. Evenness was higher in control plots in the area with soybean matrix, whereas the reverse occurred in the area with a Crotalaria matrix. Results suggest that treatment with cis-jasmone effectively attracted and enhanced the population of scelionid parasitoids, but had no effect on the occurrence and intensity of parasitism and in the number of stink bugs. 相似文献
8.
Alphonse Ouédraogo Alfred B. Tiono Désiré Kargougou Jean Baptiste Yaro Esperance Ouédraogo Youssouf Kaboré David Kangoye Edith C. Bougouma Adama Gansane Noelie Henri Amidou Diarra Souleymane Sanon Issiaka Soulama Amadou T. Konate Nora L. Watson Valerie Brown Jenny Hendriks Maria Grazia Pau Isabella Versteege Edison Wiesken Jerald Sadoff Issa Nebie Sodiomon B. Sirima 《PloS one》2013,8(11)
Background
Ad35.CS.01 is a pre-erythrocytic malaria candidate vaccine. It is a codon optimized nucleotide sequence representing the P. falciparum circumsporozoite (CS) surface antigen inserted in a replication deficient Adenovirus 35 backbone. A Phase 1a trial has been conducted in the USA in naïve adults and showed that the vaccine was safe. The aim of this study is to assess the safety and immunogenicity of ascending dosages in sub Saharan Africa.Methods
A double blind, randomized, controlled, dose escalation, phase Ib trial was conducted in a rural area of Balonghin, the Saponé health district (Burkina Faso). Forty-eight healthy adults aged 18-45 years were randomized into 4 cohorts of 12 to receive three vaccine doses (day 0, 28 and 84) of 109, 1010, 5X1010, 1011 vp of Ad35.CS.01 or normal saline by intra muscular injection. Subjects were monitored carefully during the 14 days following each vaccination for non serious adverse events. Severe and serious adverse events were collected throughout the participant study duration (12 months from the first vaccination). Humoral and cellular immune responses were measured on study days 0, 28, 56, 84, 112 and 140.Results
Of the forty-eight subjects enrolled, forty-four (91.7%) received all three scheduled vaccine doses. Local reactions, all of mild severity, occurred in thirteen (27.1%) subjects. Severe (grade 3) laboratory abnormalities occurred in five (10.4%) subjects. One serious adverse event was reported and attributed to infection judged unrelated to vaccine. The vaccine induced both antibody titers and CD8 T cells producing IFNγ and TNFα with specificity to CS while eliciting modest neutralizing antibody responses against Ad35.Conclusion
Study vaccine Ad35.CS.01 at four different dose levels was well-tolerated and modestly immunogenic in this population. These results suggest that Ad35.CS.01 should be further investigated for preliminary efficacy in human challenge models and as part of heterologous prime-boost vaccination strategies.Trial Registration
ClinicalTrials.gov NCT01018459 http://clinicaltrials.gov/ct2/show/NCT01018459 相似文献9.
Erich Y.T. Nakasu Simoni C. Dias Carmen S.S. Pires David A. Andow Debora Pires Paula Pedro Henrique B. Togni Tainã R. Macedo Edison R. Sujii Maria F.G. de Sá Eliana M.G. Fontes 《Entomologia Experimentalis et Applicata》2013,148(2):105-115
Insect predators are exposed to the Cry1Ac toxin in Bt cotton fields through several pathways. In this study, we investigated the effects of activated Cry1Ac added to a diet on Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae), which is one of the main predators of non‐target pests in Brazilian cotton. Direct bitrophic exposure of C. sanguinea to Cry1Ac was done by feeding beetles with Aphis gossypii (Glover) (Hemiptera: Aphidae) sprayed with 500 μg per ml Cry1Ac solution. Larval and pupal survival, development time, aphid consumption, and adult longevity were recorded daily. Couples within the same experimental treatment were paired and numbers of eggs laid and hatched per female were recorded daily. Net replacement rate was calculated for each female. During development, a C. sanguinea larva consumed on average 1.8 μg of activated Cry1Ac. No significant differences due to Cry1Ac were observed for any of the response variables, except aphid consumption. Larvae receiving Cry1Ac consumed more aphids than larvae receiving distilled water alone. Additional statistical analyses were conducted to evaluate independence of responses, and for the independent responses, a simple meta‐analysis was conducted to test the null hypothesis that all responses were zero. Nearly all of the response variables were statistically independent. Two pairs of responses were not independent, but the associated multivariate tests were not significant. The meta‐analysis suggested that all effects were not different from random variation around zero and no cumulative effects could be detected. Our results indicated that bitrophic exposure to activated Cry1Ac is likely to have little or no adverse ecological effect on C. sanguinea. 相似文献
10.