全文获取类型
收费全文 | 8069篇 |
免费 | 855篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 88篇 |
儿科学 | 284篇 |
妇产科学 | 208篇 |
基础医学 | 1185篇 |
口腔科学 | 198篇 |
临床医学 | 959篇 |
内科学 | 1659篇 |
皮肤病学 | 75篇 |
神经病学 | 580篇 |
特种医学 | 402篇 |
外科学 | 1176篇 |
综合类 | 198篇 |
一般理论 | 8篇 |
预防医学 | 800篇 |
眼科学 | 142篇 |
药学 | 405篇 |
1篇 | |
中国医学 | 5篇 |
肿瘤学 | 577篇 |
出版年
2021年 | 123篇 |
2020年 | 76篇 |
2019年 | 117篇 |
2018年 | 129篇 |
2017年 | 119篇 |
2016年 | 118篇 |
2015年 | 136篇 |
2014年 | 165篇 |
2013年 | 266篇 |
2012年 | 343篇 |
2011年 | 398篇 |
2010年 | 196篇 |
2009年 | 178篇 |
2008年 | 324篇 |
2007年 | 336篇 |
2006年 | 323篇 |
2005年 | 317篇 |
2004年 | 261篇 |
2003年 | 306篇 |
2002年 | 270篇 |
2001年 | 264篇 |
2000年 | 314篇 |
1999年 | 249篇 |
1998年 | 128篇 |
1997年 | 112篇 |
1996年 | 103篇 |
1995年 | 105篇 |
1994年 | 108篇 |
1993年 | 113篇 |
1992年 | 200篇 |
1991年 | 200篇 |
1990年 | 167篇 |
1989年 | 193篇 |
1988年 | 189篇 |
1987年 | 219篇 |
1986年 | 165篇 |
1985年 | 181篇 |
1984年 | 122篇 |
1983年 | 98篇 |
1982年 | 69篇 |
1981年 | 87篇 |
1980年 | 78篇 |
1979年 | 102篇 |
1978年 | 96篇 |
1976年 | 65篇 |
1975年 | 53篇 |
1973年 | 66篇 |
1972年 | 59篇 |
1971年 | 63篇 |
1970年 | 53篇 |
排序方式: 共有8950条查询结果,搜索用时 0 毫秒
61.
A reciprocal translocation is described, t(4;21)(q27;p11), which occurs in a balanced carrier mother and her Down's syndrome child, 47,XX,t(4q-;21p+),+21. A review is presented of Down's syndrome associated with reciprocal translations involving chromosome No. 21. 相似文献
62.
63.
Four-day incubation period for blood culture bottles processed with the Difco ESP blood culture system.
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
G V Doern A B Brueggemann W M Dunne S G Jenkins D C Halstead J C McLaughlin 《Journal of clinical microbiology》1997,35(5):1290-1292
Blood culture records from 1994 to 1995 from five U.S. medical centers all using the Difco ESP continuous monitoring blood culture system were reviewed retrospectively. Among a total of 7,362 isolates of bacteria and yeasts, only 0.1% of possibly significant isolates would have been missed had blood cultures been routinely incubated for 4 days instead of the 5 days recommended by the manufacturer. Conversely, numerous contaminants, detected only on day 5, would have been eliminated by a 4-day incubation period. 相似文献
64.
65.
Immunohistological study of the anatomic relationship of toxoplasma antigens to the inflammatory response in the brains of mice chronically infected with Toxoplasma gondii. 总被引:4,自引:3,他引:4
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The relationship of toxoplasma antigen(s) to the origin and long-term persistence of the mononuclear cell inflammatory infiltrate that is present in the brains of mice chronically infected with Toxoplasma gondii was studied by using the peroxidase-antiperoxidase immunohistochemical staining technique. C3H/Km mice were infected with the avirulent C37 strain of T. gondii and sequentially sacrificed over the ensuing 107 days. Comparable sections of each brain were prepared for routine light microscopy. Antisera to toxoplasma made in rabbits were used for immunohistological staining, and adjacent slides were also stained with conventional histological stains. The peroxidase-antiperoxidase stain demonstrated toxoplasma tissue cysts, tachyzoites, and intra- and extracellular antigen-antibody reaction products. Early infection was characterized by small tight clusters of free tachyzoites gaining access to brain substance in the absence of an inflammatory response. Once there was disruption of neural parenchyma, a mononuclear cellular infiltrate rapidly ensued. After the first days of infection, mononuclear cells were always present in all infected brains and were anatomically associated with some component of toxoplasma antigen(s). The histological picture of late infection suggested that recurrent episodes of hematogenous dissemination of tachyzoites occurred in infected mice and that such episodes were at least partially responsible for persistence of an antigenic stimulus. 相似文献
66.
Use of multiple PCR primer sets for optimal detection of human papillomavirus. 总被引:10,自引:7,他引:10
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
F Karlsen M Kalantari A Jenkins E Pettersen G Kristensen R Holm B Johansson B Hagmar 《Journal of clinical microbiology》1996,34(9):2095-2100
Using multiple PCR primer sets, we tried to optimize the detection of human papillomavirus (HPV) in DNA samples isolated from 361 frozen biopsy specimens from patients with invasive cervical carcinomas. The HPVs detected were placed into three distinct groups, including group I/Inex at Telelab (Skien, Norway) and group Ineg and group II at the Norwegian Radium Hospital (Oslo, Norway). The consensus primer sets were Oli-1b-oli-2i, My09-My11, Gp5-Gp6, and Gp(5+)-Gp6+ from the HPV L1 gene and CpI-CpIIG from the E1 gene. Using these consensus primers together with the type-specific primers from E6-E7, we found that 355 patients (98%) were HPV positive. Type-specific primers for HPV types 11, 16, 18, 31, 33, and 35 detected more HPV-infected patients than the most sensitive consensus primer set, while the three consensus primer sets My, Gp/Gp+, and Cp together detected more HPV-positive patients than the type-specific primers. Testing of sensitivity of the PCR with SiHa cells serially diluted in lymphocytes (HPV-negative cells) indicated a detection limit of 6,300 HPV type 16 DNA copies with consensus primers (My, Gp+, and Cp) and 126 original HPV type 16 DNA copies with type-specific primers. Comparison of the amplification results for consensus L1 primers and type-specific E6-E7 primers indicated the presence of L1 deletions in 23 of 56 samples. The conclusion is that in PCR detection systems, multiple consensus primers and type-specific primers should be used in order to detect all patients harboring HPV. 相似文献
67.
Primary and revision total knee arthroplasty have become common orthopaedic procedures. The operating surgeon, at times, may be faced with a difficult surgical case due to soft tissue contractures or bone deformities. A review of multiple surgical techniques using soft tissue releases and osteotomies are presented including their potential complications. Although these techniques are aimed at the atypical operative case, the operating surgeon may utilize them for ‘routine’ exposures as well. Importance is focused on the functional integrity of the knee extensor mechanism. 相似文献
68.
Genetic homogeneity of Taylorella equigenitalis from Norwegian trotting horses revealed by chromosomal DNA fingerprinting.
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chromosomal DNA fingerprinting indicated that Norwegian Taylorella equigenitalis strains are genetically homogeneous and similar to some Swedish isolates but different from other European strains. As contagious equine metritis is rarely a serious disease in Norwegian horses, we conclude that the dominant T. equigenitalis strain in Norway is a genetically homogeneous clone of low virulence. 相似文献
69.
GABRD encoding a protein for extra- or peri-synaptic GABAA receptors is a susceptibility locus for generalized epilepsies 总被引:11,自引:0,他引:11
Dibbens LM Feng HJ Richards MC Harkin LA Hodgson BL Scott D Jenkins M Petrou S Sutherland GR Scheffer IE Berkovic SF Macdonald RL Mulley JC 《Human molecular genetics》2004,13(13):1315-1319
A major challenge in understanding complex idiopathic generalized epilepsies has been the characterization of their underlying molecular genetic basis. Here, we report that genetic variation within the GABRD gene, which encodes the GABAA receptor delta subunit, affects GABA current amplitude consistent with a model of polygenic susceptibility to epilepsy in humans. We have found a GABRD Glu177Ala variant which is heterozygously associated with generalized epilepsy with febrile seizures plus. We also report an Arg220His allele in GABRD which is present in the general population. Compared with wild-type receptors, alpha1beta2Sdelta GABAA receptors containing delta Glu177Ala or Arg220His have decreased GABAA receptor current amplitudes. As GABAA receptors mediate neuronal inhibition, the reduced receptor current associated with both variants is likely to be associated with increased neuronal excitability. Since delta subunit-containing receptors localize to extra- or peri-synaptic membranes and are thought to be involved in tonic inhibition, our results suggest that alteration of this process may contribute to the common generalized epilepsies. 相似文献
70.
Inclusion of CpG adjuvant with plasmid DNA coding for NcGRA7 improves protection against congenital neosporosis 总被引:4,自引:0,他引:4
The present study showed that incorporation of CpG adjuvant into plasmid DNA coding for NcGRA7 antigen resulted in a twofold increase in the level of protection against congenital transfer of Neospora caninum. The level of protection was considerably higher than that observed in pups born from dams immunized with nonrecombinant plasmid. 相似文献