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   75篇
  免费   5篇
农学   3篇
  21篇
综合类   5篇
农作物   10篇
水产渔业   28篇
畜牧兽医   12篇
植物保护   1篇
  2022年   1篇
  2021年   4篇
  2020年   1篇
  2019年   2篇
  2018年   4篇
  2017年   1篇
  2016年   4篇
  2015年   2篇
  2014年   1篇
  2013年   14篇
  2011年   9篇
  2010年   1篇
  2009年   4篇
  2008年   4篇
  2007年   5篇
  2006年   2篇
  2005年   2篇
  2004年   9篇
  2003年   2篇
  2002年   1篇
  2000年   1篇
  1999年   1篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1991年   1篇
排序方式: 共有80条查询结果,搜索用时 687 毫秒
41.

The localization of metallothionein ( MT ) in the seeds and roots of soybean was investigated by immunohistochemistry. The germinating seeds at 2 hr, 1, 2, 3, 4 and 6 d including 1-mo root tips of soybean ( c.v. Toyosuzu ) with and without heavy metals ( Cu 400 μg Lor Zn 3 μg ml?1) treatment were used to demonstrate the localization of MT by the indirect immunoperoxidase technique using polyclonal rabbit antirat MT conjugated to ascaris as a primary antibody. Metallothionein was localized in the proliferating regions such as the embryo in seeds, and root and shoot apices of both the control and heavy metals-treated plants. The intensity of MT staining in the proliferating regions generally increased as the soybean seeds germinate. Starting at about 1 day after germination, MT was found in the veins and vascular bundles suggesting its translocation to other organs. Similar observation hold true in the case of plants treated with heavy metals. This means that heavy metals treatment had no effect on MT localization. However, the heavy metals-treated plants showed higher concentration of MT over the control with respect to the growth stage of soybean seeds. These indicate that MT found in soybean plays a physiological role in heavy metal transport, detoxification and cell division in a similar manner to mammalian MT.

  相似文献   
42.
Qualitative and quantitative Polymerase Chain Reaction (PCR) systems aimed at the specific detection and quantification of common wheat DNA are described. Many countries have issued regulations to label foods that include genetically modified organisms (GMOs). PCR technology is widely recognized as a reliable and useful technique for the qualitative and quantitative detection of GMOs. Detection methods are needed to amplify a target GM gene, and the amplified results should be compared with those of the corresponding taxon-specific reference gene to obtain reliable results. This paper describes the development of a specific DNA sequence in the waxy-D1 gene for common wheat (Triticum aestivum L.) and the design of a specific primer pair and TaqMan probe on the waxy-D1 gene for PCR analysis. The primers amplified a product (Wx012) of 102 bp. It is indicated that the Wx012 DNA sequence is specific to common wheat, showing homogeneity in qualitative PCR results and very similar quantification accuracy along 19 distantly related common wheat varieties. In Southern blot and real-time PCR analyses, this sequence showed either a single or a low number of copy genes. In addition, by qualitative and quantitative PCR using wx012 primers and a wx012-T probe, the limits of detection of the common wheat genome were found to be about 15 copies, and the reproducibility was reliable. In consequence, the PCR system using wx012 primers and wx012-T probe is considered to be suitable for use as a common wheat-specific taxon-specific reference gene in DNA analyses, including GMO tests.  相似文献   
43.
Objective: To describe surgical repair of a complete endocardial cushion defect (ECD) in a dog. Study Design: Clinical report. Animal: A 5‐month‐old, 9.2 kg male Shetland sheepdog. Methods: Echocardiographic examination revealed an ostium primum atrial septal defect (ASD), an inlet ventricular septal defect (VSD), mitral regurgitation (MR) and tricuspid regurgitation (TR), and a complete ECD was diagnosed. Surgical correction was performed using cardiopulmonary bypass (CPB) via right atriotomy. A polytetrafluoroethylene (PTFE) patch was secured along the margin of the inlet VSD using simple continuous suture, then the cleft in the septal mitral leaflet was sutured. Similarly, the cleft in the septal tricuspid leaflets was sutured. To complete inlet VSD closure, the VSD patch was secured to these sutured leaflets by simple continuous suture. Another PTFE patch was used to close the ostium primum ASD. Result: After surgery, MR, TR, and interventricular shunting were decreased. The dog was alive 6 years and 5 months after the surgery with no evidence of an interventricular shunt, TR, or other clinical signs. Conclusions: Complete ECD in a dog was corrected using a 2‐patch technique under CPB.  相似文献   
44.
Myosin V is a molecular motor that moves cargo along actin filaments. Its two heads, each attached to a long and relatively stiff neck, move alternately forward in a "hand-over-hand" fashion. To observe under a microscope how the necks move, we attached a micrometer-sized rod to one of the necks. The leading neck swings unidirectionally forward, whereas the trailing neck, once lifted, undergoes extensive Brownian rotation in all directions before landing on a site ahead of the leading head. The neck-neck joint is essentially free, and the neck motion supports a mechanism where the active swing of the leading neck biases the random motion of the lifted head to let it eventually land on a forward site.  相似文献   
45.
The rDNA PCR–RFLP of foxtail millet (Setaria italica) germ-plasm collected throughout Eurasia and from a part of Africa was investigated with five restriction enzymes according to our previous study. Foxtail millet germ-plasms were classified by length of the rDNA IGS and RFLP; clear geographical differentiation was observed between East Asia, the Nansei Islands of Japan-Taiwan-the Philippines area, South Asia and Afghanistan-Pakistan. We also found evidence of migration of foxtail millet landraces between the areas. We calculated diversity index (D) for each region and found that center of diversity of this millet is East Asia such as China, Korea and Japan.  相似文献   
46.
ABSTRACT

Green stem disorder (GSD) in soybean (Glycine max (L.) Merrill) negatively affects harvest efficiency and seed appearances. Breeding GSD-insensitive cultivars is expected to be an effective countermeasure to GSD. However, it is difficult to stably detect cultivar differences in GSD under conventional field conditions because the occurrences of GSD largely vary by location and year. The thinning effect, which had been reported to promote GSD, may help accurate phenotyping for occurrences of GSD in breeding. To verify this possibility, the thinning treatment was applied to four cultivars, the GSD severity values of which were evaluated in an independent study by another group. As a result, the cultivar differences in GSD severity were generally comparable between the present and previous studies. However, the difference was more evident, with the thinning treatment exhibiting the GSD score of 2.8 of ‘Hatsusayaka’ compared with the GSD score of 3.6 of ‘Sachiyutaka’, while the scores of those cultivars were similar without the thinning treatment. A positive correlation between GSD severity and N concentration in the main stem could be seen but the increasing rate of GSD score with the N concentration in the main stem differed between cultivars. Thus, although more cultivars need to be tested to prove, the thinning treatment could be useful as a phenotyping technique in the breeding of GSD-insensitive cultivars.  相似文献   
47.
Hybrid weakness is a reproductive barrier. In rice, the hybrid weakness caused by two complementary genes––HWC1 and HWC2––has been surveyed extensively. However, their gene products and the molecular mechanism that causes hybrid weakness have remained unknown. We first performed fine mapping of HWC2, narrowing down the area of interest to 19 kb. We thereby identified five candidate genes. Second, we performed haplotype analysis around the HWC2 locus of 33 cultivars. With 15 DNA markers examined, all the 13 Hwc2-1 carriers share the same haplotype for consecutive 14 DNA markers. As for hwc2-2 carriers, five out of 20 have the haplotypes relatively similar to those of Hwc2-1 carriers. However, the other haplotypes differ remarkably from them. These results are useful to identify the HWC2 gene and to study rice varietal differentiation.  相似文献   
48.
Size at sexual maturity and body size composition of mud crabs Scylla spp. were examined as the basis for settling a minimum landing size as a fishing regulation in Don Sak, Bandon Bay, Gulf of Thailand, which has suffered serious mangrove habitat degradation. Mud crabs were caught using baited traps and gill nets. Hooked metal rods were also used to lever the crabs out of their burrows inside the mangroves. Two mud crab species, S. paramamosain and S. olivacea, occur in the bay; S. paramamosain is the dominant species, accounting for 87% of the samples. The size at which 50% of the S. paramamosain females reached maturity (SM50) was estimated as an external carapace width (ECW) of 112.0 mm based on the morphology of the abdomen. Allometric changes in the crushing chelae height to ECW ratio suggested that the SM50 of S. paramamosain males occurred at 106.4 mm ECW. The body size composition revealed that mainly immature mud crabs were exploited in Don Sak. To maintain a sustainable fishery for mud crabs, fishing regulations—including a minimum landing size based on the SM50 estimates—are essential, as is habitat restoration.  相似文献   
49.
ABSTRACT:   The genetic diversity of wild and hatchery-released Pacific herring Clupea pallasii collected from three brackish lakes and two bays in Honshu and Hokkaido, Japan was examined with five microsatellite loci. All loci showed high genetic variability with expected heterozygosities ranging from 0.815 to 0.945. Significant differences in genotypic and allelic distributions were detected among all locations except for between the two bays in Honshu Island. Pairwise population analysis based on the F ST values showed close genetic relationships among the locations in Hokkaido Island, and the hierarchical analyses of molecular variance showed significant genetic difference between the two islands. Those results suggest the existence of subpopulations due to natal homing. In addition, stocked fish showed as much genetic diversity as the wild fish. The pairwise population analyses also showed close relationships between the hatchery fish and the wild fish in respective stocking areas, showing that no effects of stocking programs on genetic diversity of wild populations were detected.  相似文献   
50.
Soil is closely connected to the culture and civilization of an ethnic group living in a given place, including their religion, thoughts, livelihood and health. It is important for people to protect the soil, their agriculture and the environment because the collapse of soil leads to the collapse of human culture, civilization, livelihood and health. The links between the soil and culture, civilization, livelihood and health may result from the ethical attitudes people have about the soil and that they demonstrate through their interactions with it. However, soil resources have been overexploited in modern society and are currently on the verge of collapsing. In this review article, the etymology of words for soil, the place of soil in philosophy and religion, the relationships between soil and the soul, the soil and dialects, and cultural soil science are discussed. The powerful influences of soil on civilization and livelihood are discussed and the relationship between soil and human beings is also considered. Soil can be shown to be a living thing, and this review will present a brief history of the relationship between soil and human health, and will discuss the importance of adopting an ethical attitude towards soil.  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