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   31篇
  免费   0篇
林业   2篇
农学   2篇
  4篇
综合类   3篇
水产渔业   2篇
畜牧兽医   15篇
植物保护   3篇
  2022年   1篇
  2016年   2篇
  2015年   1篇
  2014年   2篇
  2013年   1篇
  2012年   2篇
  2010年   1篇
  2008年   3篇
  2007年   1篇
  2006年   1篇
  2004年   1篇
  2002年   1篇
  2001年   1篇
  1999年   2篇
  1995年   1篇
  1987年   2篇
  1986年   1篇
  1985年   2篇
  1984年   3篇
  1983年   2篇
排序方式: 共有31条查询结果,搜索用时 15 毫秒
11.
The edible mushroom Agaricus blazei Murill is considered a health food in many countries after it was reported to be a source of antitumor and immunoactive compounds. An aqueous extract (AE) from this basidiomycete significantly enhanced the expression of the c-Jun/activator protein-1 (AP1) in the human breast cancer cell line MCF7. Incubating the cells with 17-beta-estradiol (E2), p-nonylphenol (NP), and the AE combined, or NP plus the AE, resulted in increased cell proliferation compared to the untreated control by 93 and 67%, respectively. However, incubating the cells with the extract alone did not enhance cell division. It is suggested that the enhanced proliferation of MCF7 cells in the presence of NP and the AE may be due to the involvement of an AP1 gene regulatory complex. This is the first report showing enhanced c-Jun/AP1 expression in MCF7 cells incubated with an aqueous fungal extract.  相似文献   
12.
The roles of celomic membranes and celomic structures in preventing cancer metastasis were examined. The relationship between a tunnel in the peritoneal cavity of hens and the cancer metastasis was also investigated. A tunnel between the right and left dorsal hepatic cavities was found in almost half of healthy hens. The tunnel was also found in 17% of hens with cancer. Neoplastic cells were detected in the ascitic fluid of 79% of hens with effusions. Metastasis was most severe in the intestinal peritoneal and left dorsal hepatic cavities, whereas the right dorsal hepatic cavity showed the least involvement. Severe inflammatory responses were found within the metastatic membranes, resulting in an increase in their thickness. In tumor-bearing hens, crevasse-like splits were present within the membranes at the layers of loose connective tissues. It appears that the splits prevent further invasion by the cancer cells. There were no successful lesions on the inner surfaces of air sacs. It is suggested that the tunnel in the peritoneal cavity enhances cancer metastasis. We also conclude that the celomic membranes and their structure in hens retard the spread of cancer by functioning as a barrier against direct spread of the cancer cells.  相似文献   
13.
14.
The sex ratios of the nigorobuna Carassius auratus grandoculis reared in paddy fields during the sex differentiation periods of larval and juvenile stages were examined, since the phenotypic expression of sex in the fish is thermolabile, so that sex determination is under the control of genetic factors and temperature. After 2 days from hatching, the larvae were introduced into five paddy fields at five different densities in late May. After 37 or 41 days from hatching the juveniles were collected when the water was drained from the paddy fields, and reared in laboratory tanks supplied with running freshwater pumped from the lake shore until the age of 144–164 days. The mean water temperatures in the paddy fields were 22.4–24.1 ºC, and the maximum water temperature during the day frequently exceeded 30 ºC during the supposed critical period of sex determination of the fish. The sex ratios in the five paddy fields did not show a male-bias. Instead, all fields produced either balanced or slightly female-bias sex ratios. These results suggest that temporary high and fluctuating temperatures in paddy fields with low mean temperatures have hardly any masculinization effects on genotypic females of C. auratus grandoculis during sex differentiation stages.  相似文献   
15.
16.
The relationships between photochemical reflectance index (PRI) and the chlorophyll fluorescence parameters were examined to assess suitability of PRI as a remote-sensing tool for the chlorophyll fluorescence parameters. A greenhouse experiment was conducted using cotton and peanut crops under water stress condition. Five cotton and six peanut cultivars were grown using Andosole soil in pots maintained at two water levels; the control and water stress treatment (WS) of 100 and 50% of the daily transpiration, respectively. Higher non-photochemical quenching (NPQ) was exhibited by peanut than that of cotton by the water stress. On the other hand, the decreases of the actual quantum yield of photosystem II (△F/F'm) and PRI by the water stress in cotton were larger than those in peanut. There were positively significant correlation coefficients between PRI and △F/F'm in cotton at noon and in the afternoon including the control and WS. The correlations of PRI with NPQ were negatively significant at noon and in the afternoon for cotton, and in the afternoon for peanut. No clear relationship was found among these parameters in the morning probably due to the diurnal increase in global solar radiation. It was concluded that there would be a possibility to detect the effects of water stress on △F/F'm and NPQ by PRI with some exceptions, although PRI could not note varietals differences in △F/F'm and NPQ for each treatment.  相似文献   
17.
The origin of adenocarcinomas in 10 hens was studied using an assay for estradiol receptors (ERs) and ovalbumin. ERs were found in nine tumors, and ovalbumin was present in eight tumors. Hormonal regulation of this cancer is indicated, and it is suggested that the origin of the tumor is probably the glands of the oviduct.  相似文献   
18.
Development of vaccine strains of H5 and H7 influenza viruses   总被引:1,自引:0,他引:1  
To establish vaccine strains of H5 and H7 influenza viruses, A/duck/Hokkaido/Vac-1/04 (H5N1) [Vac-1/04 (H5N1)], A/duck/Hokkaido/Vac-3/07 (H5N1) [Vac-3/07 (H5N1)], and A/duck/Hokkaido/ Vac-2/04 (H7N7) [Vac-2/04 (H7N7)] were generated from non-pathogenic avian influenza viruses isolated from migratory ducks. Vac-1/04 (H5N1) and Vac-3/07 (H5N1) were generated by genetic reassortment between H5N2 or H5N3 virus as an HA gene provider and H7N1 or H6N1 viruses as an NA gene provider. Vac-2/04 (H7N7) was a genetic reassortant obtained using H7N7 and H9 N2 viruses to give high growth character of the H9N2 virus in chicken embryonated eggs. The results of sequence analyses and experimental infections revealed that these H5N1 and H7N7 reassortant viruses were non-pathogenic in chickens and embryos, and had good growth potential in embryonated eggs. These viruses should be useful to develop vaccines against H5 and H7 highly pathogenic avian influenza viruses.  相似文献   
19.
Eleven cotton (Gossypium hirsutum L.) cultivars were evaluated for their growth and yield performance in Shihezi, Xinjiang, China, an area in Central Asia with short growing period in 1999 and 2000. In each cultivar the number of bolls per plant was low and the number of bolls per unit area was high. Each cultivar showed rather high seed and lint yields. The highest lint yield was Xinluzao 10 in both years with 1761 and 1809 kg ha?1. High yield ability of the cultivars in this study was attributed to large number of bolls per unit area with high lint percentage. Seed and lint yields had significant positive correlations with mean net assimilation rate, ratio of reproductive to vegetative organs and mean boll weight at earlier stages of boll growth, suggesting that early boll formation and successive partitioning of dry matter into bolls were important factors for boll growth in this study area.  相似文献   
20.
This study was designed to test the lipid-lowering and antioxidative activities of triacetylated hydroxytyrosol compared with its native compound, hydroxytyrosol, purified from olive tree leaves. Wistar rats fed a standard laboratory diet or a cholesterol-rich diet for 16 weeks were used. The serum lipid levels, the thiobarbituric acid-reactive substances (TBARS) level, as an indicator of lipid peroxidation, and the activity of superoxide dismutase (SOD) as well as that of catalase (CAT) were examined. The cholesterol-rich diet induced hypercholesterolemia that was manifested in the elevation of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C). Administration of hydroxytyrosol and triacetylated hydroxytyrosol (3 mg/kg of body weight) decreased the serum levels of TC, TG, and LDL-C significantly and increased the serum level of high-density lipoprotein cholesterol (HDL-C). Furthermore, the content of TBARS in liver, heart, kidney, and aorta decreased significantly when hydroxytyrosol and its triacetylated derivatives were orally administered to rats compared with those fed a cholesterol-rich diet. In addition, triacetylated hydroxytyrosol and hydroxytyrosol increased CAT and SOD activities in the liver. These results suggested that the hypolipidemic effect of triacetylated hydroxytyrosol and hydroxytyrosol might be due to their abilities to lower serum TC, TG, and LDL-C levels as well as to their antioxidant activities preventing the lipid peroxidation process.  相似文献   
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