全文获取类型
收费全文 | 8489篇 |
免费 | 542篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 128篇 |
儿科学 | 654篇 |
妇产科学 | 155篇 |
基础医学 | 1033篇 |
口腔科学 | 153篇 |
临床医学 | 561篇 |
内科学 | 1716篇 |
皮肤病学 | 329篇 |
神经病学 | 476篇 |
特种医学 | 375篇 |
外科学 | 934篇 |
综合类 | 198篇 |
一般理论 | 4篇 |
预防医学 | 520篇 |
眼科学 | 333篇 |
药学 | 649篇 |
中国医学 | 37篇 |
肿瘤学 | 803篇 |
出版年
2023年 | 76篇 |
2022年 | 171篇 |
2021年 | 319篇 |
2020年 | 217篇 |
2019年 | 265篇 |
2018年 | 316篇 |
2017年 | 195篇 |
2016年 | 247篇 |
2015年 | 234篇 |
2014年 | 359篇 |
2013年 | 412篇 |
2012年 | 596篇 |
2011年 | 583篇 |
2010年 | 320篇 |
2009年 | 276篇 |
2008年 | 382篇 |
2007年 | 403篇 |
2006年 | 383篇 |
2005年 | 340篇 |
2004年 | 311篇 |
2003年 | 269篇 |
2002年 | 248篇 |
2001年 | 165篇 |
2000年 | 154篇 |
1999年 | 142篇 |
1998年 | 76篇 |
1997年 | 45篇 |
1996年 | 54篇 |
1995年 | 37篇 |
1994年 | 46篇 |
1993年 | 43篇 |
1992年 | 96篇 |
1991年 | 100篇 |
1990年 | 101篇 |
1989年 | 92篇 |
1988年 | 78篇 |
1987年 | 85篇 |
1986年 | 61篇 |
1985年 | 63篇 |
1984年 | 66篇 |
1983年 | 47篇 |
1982年 | 64篇 |
1981年 | 75篇 |
1980年 | 73篇 |
1979年 | 58篇 |
1978年 | 34篇 |
1976年 | 35篇 |
1974年 | 28篇 |
1973年 | 31篇 |
1970年 | 27篇 |
排序方式: 共有9058条查询结果,搜索用时 0 毫秒
31.
32.
Y. N. Mchra S. B. S. Mann S. P. Dubey A. Verma S. Suri 《Indian journal of otolaryngology and head and neck surgery》1989,41(2):43-47
Due to deep seated location and presence of vital structures, the tumours of the parapharyngeal space poses difficulty in
its early diagnosis, histological nature and surgical extirpation. Modes of radiological assessment in pre-computed tomography
(GT) scan era were sialography of the parotid gland to see whether the tumour is of salivary origin and angiography to note
the vascularity of the tumour. Post CT scan era has changed the assessment protocol. In this article, the authors have tried
to make a comparative evalua?tion between non-contrast GT, GT with systemic contrast and GT sialogram in 14 cases of parapharyngeal
tumours. Angiography was done only when the tumours showed marked enhancement with systemic contrast. Subsequently, 13 patients
underwent surgery for removal of the mass. Application of high-resolution GT helped in not only to see the extent of the tumour
but also to pinpoint the probable histologic nature. 相似文献
33.
Current models hold that CD4+ depletion occurs as a result of direct and indirect effects of HIV, which both kill peripheral
CD4+ cells and prevent adequate regeneration. Although age-associated involution diminishes thymic reserve and HIV is clearly
thymotoxic, clinical trials have nonetheless shown that large proportions of patients who sustain adequate control of viral
replication with highly active antiretroviral therapy (HAART) will demonstrate some evidence for thymic-dependent immune reconstitution,
which is associated with improved immune competence. Furthermore, patients with insufficient or absent immune reconstitution
following HAART generally lack evidence for thymopoiesis. Current studies are focused on improving our understanding of the
causes for thymic failure in HIV infection. Recent work has demonstrated that some HIV strains, especially those that are
CXCR4 trophic, are more thymotoxic and may contribute to irreversible thymic damage in this population. 相似文献
34.
35.
Ornithine decarboxylase activity as a biochemical marker in individuals predisposed to lung cancer 总被引:1,自引:0,他引:1
Ornithine decarboxylase (ODC) is the first enzyme in the pathway of mammalian polyamine biosynthesis. "Tumor promoters" appear to induce ODC. In addition, increased ODC activity has been observed in normal appearing colonic mucosa of patients with familial polyposis, an autosomal dominant disorder associated with a high incidence of colon cancer. Ornithine decarboxylase activity was measured in bronchoscopic mucosal biopsy specimens from the noninvolved lung in patients with unilateral lung masses. No correlation could be determined in ODC levels from "normal" mucosa between patients with lung cancer compared to those with benign disease, despite elevated ODC activity in the tumors themselves. 相似文献
36.
Current models hold that CD4+ depletion occurs as a result of direct and indirect effects of HIV, which both kill peripheral CD4+ cells and prevent adequate regeneration. Although age-associated involution diminishes thymic reserve and HIV is clearly thymotoxic, clinical trials have nonetheless shown that large proportions of patients who sustain adequate control of viral replication with highly active antiretroviral therapy (HAART) will demonstrate some evidence for thymic-dependent immune reconstitution, which is associated with improved immune competence. Furthermore, patients with insufficient or absent immune reconstitution following HAART generally lack evidence for thymopoiesis. Current studies are focused on improving our understanding of the causes for thymic failure in HIV infection. Recent work has demonstrated that some HIV strains, especially those that are CXCR4 trophic, are more thymotoxic and may contribute to irreversible thymic damage in this population. 相似文献
37.
The Mouse Secretome: Functional Classification of the Proteins Secreted Into the Extracellular Environment 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Genome research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
38.
- Cimetidine produced dose-dependent contractions in isolated guinea pig ileum and these responses were not blocked by mepyramine the H1-receptor antogonist.
- Atropine competitively inhibited the cimetidine-induced contractions in the guinea pig ileum.
- Cimetidine-induced reponses were potentiated in the presence of eserine.
39.
Rajashree Gudi Adolfo Elizalde Swarna K. Gogineni Michael J. Macera Adolfo Badillo Ram S. Verma 《Cancer Genetics and Cytogenetics》1996,90(2):142-145
A patient was referred with a high leukocyte count and diagnosed with chronic myelogenous leukemia (CML). Although practically asymptomatic since the time of diagnosis, he had a variable and inconsistent response to treatment. All of his bone marrow cells had a complex, three-way translocation, involving chromosomes 4, 9 and 22. Translocation of chromosome 4 to chromosome 9 was undetectable by routine cytogenetic techniques; however, by the fluorescence in situ hybridization technique, a three-way translocation was identified, 46,XYt(4;9;22)(p16;q34;q11). Although, other chromosomes are frequently involved in complex or variant translocations with chromosome 9 and 22, participation of chromosome 4 is a very rare event. So far, two previous cases have been described in the literature with translocations involving chromosome 4p16. We present a third case of CML having similar break points whose clinical presentation is unusual. 相似文献
40.
Humphrey RK Beattie GM Lopez AD Bucay N King CC Firpo MT Rose-John S Hayek A 《Stem cells (Dayton, Ohio)》2004,22(4):522-530