首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   147篇
  免费   5篇
  国内免费   1篇
  2023年   3篇
  2021年   3篇
  2020年   4篇
  2019年   3篇
  2018年   4篇
  2017年   3篇
  2016年   3篇
  2015年   11篇
  2014年   12篇
  2013年   18篇
  2012年   17篇
  2011年   14篇
  2010年   10篇
  2009年   5篇
  2008年   6篇
  2007年   7篇
  2006年   5篇
  2005年   6篇
  2004年   4篇
  2003年   2篇
  2002年   1篇
  1996年   1篇
  1990年   1篇
  1986年   1篇
  1981年   1篇
  1980年   2篇
  1978年   1篇
  1975年   1篇
  1972年   2篇
  1970年   1篇
  1965年   1篇
排序方式: 共有153条查询结果,搜索用时 171 毫秒
121.
Plasmonics - In this paper, we report fabrication of a simple, stable, low-cost, and easy-to-fabricate substrate for surface enhanced Raman spectroscopy (SERS) applications. Silicon...  相似文献   
122.
Bee products have been used since ancient times to treat many diseases, including respiratory ailments. The present study aimed to examine the modulatory effect of honey, royal jelly, and propolis extract on peripheral blood leukocytes and lung inflammation in a mouse conalbumin-induced asthma model. The mice in group I were not sensitised or treated; they were kept as controls. The mice in group II were sensitised and challenged with conalbumin. Twenty-four hours after the first challenge with antigen, the mice in group III received 0.5 mg/kg of dexamethasone intraperitoneally per day for 18 consecutive days and kept as positive controls. The mice in groups IV, V, and VI received 650, 1000, and 30 mg/kg of honey, royal jelly, and propolis (aqueous and ethanolic extract), respectively, once per day for 18 consecutive days. Blood was collected from all of the mice for white blood cell differentiation, and the lungs were removed for histopathological studies. The groups treated with propolis extract exhibited considerable ameliorative effects against asthma, which might be explained by the flavonoids and phenolics found in propolis, which might have antioxidative effects. Otherwise, the sensitised and honey- or royal jelly-treated groups exhibited an increased incidence of asthma cascade events due to increased inflammatory cells. These results might be due to the immunostimulatory and vasodilatory effects of royal jelly and honey, which are antagonistic to bronchial asthma cases. Histopathological examination revealed that the sensitised treated propolis extract groups had significant decreases in inflammatory scores compared with other treatments and the sensitised untreated group. These results confirmed the previous data of peripheral blood cells.  相似文献   
123.
Osseous abnormalities, including long-bone dysplasia with pseudarthrosis (PA), are associated with neurofibromatosis type 1 (NF1). Prospectively acquired tissue from the PA site of two individuals with NF1 was used for immunohistochemical characterization and genotype analysis of the NF1 locus. Typical immunohistochemical features of neurofibroma were not observed. Genotype analysis of PA tissue with use of four genetic markers (D17S1863, GXALU, IN38, and 3NF1-1) spanning the NF1 locus demonstrated loss of heterozygosity. These results are the first to document double inactivation of NF1 in PA tissue and suggest that the neurofibromin-Ras signal transduction pathway is involved in this bone dysplasia in NF1.  相似文献   
124.
125.
Phenotypic screens can identify molecules that are at once penetrant and active on the integrated circuitry of a whole cell or organism. These advantages are offset by the need to identify the targets underlying the phenotypes. Additionally, logistical considerations limit screening for certain physiological and behavioral phenotypes to organisms such as zebrafish and C. elegans. This further raises the challenge of elucidating whether compound-target relationships found in model organisms are preserved in humans. To address these challenges we searched for compounds that affect feeding behavior in C. elegans and sought to identify their molecular mechanisms of action. Here, we applied predictive chemoinformatics to small molecules previously identified in a C. elegans phenotypic screen likely to be enriched for feeding regulatory compounds. Based on the predictions, 16 of these compounds were tested in vitro against 20 mammalian targets. Of these, nine were active, with affinities ranging from 9 nM to 10 µM. Four of these nine compounds were found to alter feeding. We then verified the in vitro findings in vivo through genetic knockdowns, the use of previously characterized compounds with high affinity for the four targets, and chemical genetic epistasis, which is the effect of combined chemical and genetic perturbations on a phenotype relative to that of each perturbation in isolation. Our findings reveal four previously unrecognized pathways that regulate feeding in C. elegans with strong parallels in mammals. Together, our study addresses three inherent challenges in phenotypic screening: the identification of the molecular targets from a phenotypic screen, the confirmation of the in vivo relevance of these targets, and the evolutionary conservation and relevance of these targets to their human orthologs.  相似文献   
126.
Habrobracon hebetor Say (Hymenoptera: Braconidae) is one of the most important natural enemies that has been used for biological control of lepidopteran pests, so the sub-lethal effects of imidacloprid, abamactin and Bacillus thuringiensis Berliner (Bt) on progeny sex ratio (male/total) and adult longevity of H. hebetor were examined under laboratory conditions. It was found that the progeny sex ratio changed to male bias significantly by Bt treatment. Also, the adult longevity of the wasp was affected adversely by insecticides treatment and it was longest in Bt treatment. In conclusion, the current results indicated that the sub-lethal concentration of these insecticides affected the progeny sex ratio and adult longevity and the best strategies for reduction of hazard to the H. hebetor in combination with Bt is to avoid their application before Bt spraying.  相似文献   
127.
128.
Tospovirus has emerged as a serious viral pathogen for several crops including tomato. The tomato production is being severely affected worldwide by Tospovirus. Some reports have been published about the association of plant virus and development of human disease either by direct or indirect consumption. Resistance to this virus has been identified as good source in wild tomato species (Lycopersicum peruvianum). But the introgression of resistance genes into cultivated tomato lines and the development of interspecific hybrid are hampered due to incompatibility, fertilization barriers and embryo abortion. But this barrier has been broken by applying the embryo rescue methods. This study describes the development of interspecific hybrid tomato plants by highly efficient embryo rescue method and screening for Tospovirus resistance. The interspecific hybrid tomato plants were developed by making a cross between wild tomato species (L. peruvianum) and cultivated tomato (Solanum lycopersicum). The immature embryos were cultured in standardized medium and interspecific hybrids were developed from embryogenic callus. The immature embryos excised from 7 to 35 days old fruits were used for embryo rescue and 31 days old embryos showed very good germination capabilities and produced the highest number of plants. Developed plants were hardened enough and shifted to green house. The hybrid nature of interspecific plants was further confirmed by comparing the morphological characters from their parents. The F1, F2 and F3 plants were found to have varying characters especially for leaf type, color of stem, fruits, size, shapes and they were further screened for virus resistance both in lab and open field followed by Enzyme linked Immunosorbant Assay confirmation. Finally, a total of 11 resistant plants were selected bearing red color fruits with desired shape and size.  相似文献   
129.
BACKGROUND: Dirofilariasis due to Dirofilaria repens with viable microfilariae outside the worm have not been reported before. CASE: A 40-year-old truck driver from rural Shiraz, Iran, had a firm mass, 2.5 x 2.5 cm, at the dorsolateral aspect of the right forearm. Fine needle aspiration (FNA) was performed on 2 occasions. Several microfilariae with blunt heads, pointed posterior ends and empty caudal spaces resembling microfilariae of Wuchereria bancrofti but longer were seen. Since Iran is a nonendemic area for lymphatic filariae and the patient had a history of contact with a dog, with the impression of dirofilariasis, the mass was excised, and the presence of adult worms in tissue sections confirmed the diagnosis. CONCLUSION: This case ofsubcutaneous dirofilariasis was diagnosed by detecting microfilariae in FNA smears and was confirmed on histopathology.  相似文献   
130.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号