全文获取类型
收费全文 | 220篇 |
免费 | 21篇 |
国内免费 | 1篇 |
专业分类
基础医学 | 15篇 |
口腔科学 | 3篇 |
临床医学 | 1篇 |
内科学 | 68篇 |
皮肤病学 | 2篇 |
神经病学 | 3篇 |
特种医学 | 5篇 |
外科学 | 2篇 |
综合类 | 53篇 |
预防医学 | 45篇 |
药学 | 28篇 |
中国医学 | 17篇 |
出版年
2022年 | 4篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 11篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 12篇 |
2013年 | 14篇 |
2012年 | 7篇 |
2011年 | 13篇 |
2010年 | 9篇 |
2009年 | 10篇 |
2008年 | 18篇 |
2007年 | 8篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 15篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有242条查询结果,搜索用时 11 毫秒
1.
遥感技术在蚊虫孳生地监测中的应用 总被引:2,自引:0,他引:2
遥感技术作为一种快速、有效的监测工具,目前在国外已越来越多地应用于蚊虫调查和防治研究中。本文就遥感技术的原理、方法、以及在蚊虫研究中的应用作一概述,并对遥感在我国蚊虫研究的应用前景予以展望。 相似文献
2.
目的探讨被转入的人SR-AI基因的整合与复制情况及其对小鼠繁育的影响.方法采用类似系祖建系的方法,对人SR-AI转基因小鼠的2、3534、3560、3638、3639五个系列进行了繁育.并用PCR和Southermblot的方法,检测五个系列小鼠尾组织的DNA样品.结果五个系列小鼠共产仔431只,PCR检出阳性小鼠178只,阳性率为41.2%.在3639系的F1、F2、F3代及纯合子转基因鼠中PCR阳性率分别为47.8%、71.3%、75%和100%.结论人SR-AI基因在子代鼠中能稳定遗传,且对生殖和发育无明显影响. 相似文献
3.
目的对广州地区西藏小型猪的繁殖性能和繁殖行为进行了观察研究。方法以广州地区雌雄西藏小型猪为研究对象,根据其繁殖卡的详细资料进行分类统计。结果雄性西藏小型猪阴茎首次伸出日龄为(39.50±2.63)d,此时体重为(3.26±0.87)kg;其射精日龄为(65.22±3.69)d,体重为(5.34±1.03)kg。雌性西藏小型猪初情日龄为(142±5.3)d,成年母猪发情周期为(20.35±0.72)d,发情持续期(4.2±0.31)d;其妊娠期约为114 d左右。初产雌性西藏小型猪产仔数为(2.30±0.82)头,2月龄断乳存活率为86.5%;而经产雌性西藏小型猪产仔数为(5.70±1.00)头,其2月龄断乳存活率为91.4%。哺乳期雌性西藏小型猪母性强,护仔行为强烈。结论广州地区西藏小型猪生长发育繁殖正常,产仔率和2月龄存活率等繁殖性能指标与原产地一致。 相似文献
4.
中国野生獐资源保护与饲养 总被引:7,自引:0,他引:7
我国现存的四大野生獐种群不容乐观,它们的分布区已大为缩小并分割成块,栖息地遭到破坏,种群数量过少.因而保护应以栖息地为重点,人工饲养可以成为解决目前野生獐种群保护与利用之间平衡的一种有效手段. 相似文献
5.
6.
摘要:目的 通过对新硫肽类抗生素166A产生菌小单孢菌TMD166进行诱变选育研究,以期获得产166A的高产菌株。方
法 使用多功能等离子体诱变系统(multifunctional plasma mutagenesis system, MPMS)对出发菌株TMD166的孢子进行等离子体-紫
外(MPMS-UV)复合诱变,单孢子悬液经照射处理、涂布培养后获得单菌落,并以牛津杯固体发酵高通量筛选方法对菌株进行初
筛,之后对高产菌株进行摇瓶复筛,利用突变株摇瓶发酵的化学效价筛选出正突变菌株。结果 对比MPMS-UV不同诱变剂量发
现,MPMS105s-UV60s复合诱变剂量获得的正突变率最高,达到41.43%,相应致死率为99.88%。最终筛选出一株166A高产突
变株TMD166-MU1,在培养温度为28℃、210 r/min的条件下,经过96~120 h培养后,166A产量相比出发菌株提高了7.47倍。结
论 采用MPMS-UV复合诱变方式,再结合牛津杯固体发酵高通量筛选方法和摇瓶复筛,可高效筛选获得166A高产菌株。 相似文献
7.
Although medicinal plants have been historically used for diabetes treatment throughout the world, few of them have been validated by scientific criteria. Recently, a large diversity of animal models has been developed to better understand the pathogenesis of diabetes mellitus and new drugs have been introduced in the market to treat this disease. The aim of this work was to review the available animal models of diabetes and some in vitro models which have been used as tools to investigate the mechanism of action of drugs with potential antidiabetic properties. In addition, a MEDLINE/PUBMED search for articles on natural products, pancreatectomy and diabetes mellitus treatment published between 1996 and 2006 was done. In the majority of the studies, natural products mainly derived from plants have been tested in diabetes models induced by chemical agents. This review contributes to the researcher in the ethnopharmacology field to designs new strategies for the development of novel drugs to treat this serious condition that constitutes a global public health. 相似文献
8.
9.
10.
《Vaccine》2018,36(11):1444-1452
NAb are defined as antigen binding antibodies present without a known previous exposure to this antigen. NAb are suggested to enhance specific antibody (SpAb) responses, but consequences of different NAb levels on immunization are largely unknown. Layer chickens were divergently selected and bred for keyhole limpet hemocyanin (KLH)-binding NAb titers, resulting in a High line and a Low line. In this study, we investigated: (1) the relation of NAb levels with SpAb titers; and (2) the effect of immunization on NAb titers. The 50 highest females of the High line and the 50 lowest females of the Low line of generation 2 were intramuscularly immunized at 33 weeks of age with 1 mL phosphate buffered saline (PBS) containing one of four treatments: (1) negative control (no antigen), (2) 500 µg KLH, (3) 100 µg avian tuberculin purified protein derivative of Mycobacterium avium (PPD), or (4) 250 µg human serum albumin (HuSA). IgM and IgG titers of NAb and SpAb in plasma were determined prior to immunization and weekly for 5 weeks post immunization by indirect ELISA. In addition, antibody affinity was investigated. No differences in SpAb and NAb response against KLH and PPD were observed as a consequence of different NAb titers, but increased and prolonged SpAb and NAb titer responses against HuSA were observed for the High line compared to the Low line. Different natural antibody titers did not impair SpAb dynamics and SpAb affinity. NAb titers were not, or for only short-term, affected by immunization. We show here that NAb may enhance SpAb responses, but that this effect is antigen-dependent. We hypothesize that NAb play a role in general disease resistance through enhancement of the humoral adaptive immune response. 相似文献