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   19473篇
  免费   979篇
  国内免费   90篇
耳鼻咽喉   88篇
儿科学   271篇
妇产科学   229篇
基础医学   2520篇
口腔科学   527篇
临床医学   1323篇
内科学   4611篇
皮肤病学   269篇
神经病学   1688篇
特种医学   985篇
外科学   3927篇
综合类   75篇
预防医学   496篇
眼科学   360篇
药学   1464篇
中国医学   46篇
肿瘤学   1663篇
  2023年   85篇
  2022年   183篇
  2021年   369篇
  2020年   160篇
  2019年   247篇
  2018年   363篇
  2017年   274篇
  2016年   304篇
  2015年   306篇
  2014年   418篇
  2013年   545篇
  2012年   827篇
  2011年   942篇
  2010年   489篇
  2009年   426篇
  2008年   775篇
  2007年   915篇
  2006年   939篇
  2005年   894篇
  2004年   832篇
  2003年   809篇
  2002年   816篇
  2001年   776篇
  2000年   790篇
  1999年   725篇
  1998年   241篇
  1997年   202篇
  1996年   165篇
  1995年   136篇
  1994年   131篇
  1993年   145篇
  1992年   524篇
  1991年   464篇
  1990年   435篇
  1989年   431篇
  1988年   416篇
  1987年   356篇
  1986年   355篇
  1985年   356篇
  1984年   200篇
  1983年   165篇
  1982年   83篇
  1979年   169篇
  1978年   124篇
  1977年   91篇
  1974年   124篇
  1973年   113篇
  1972年   81篇
  1970年   83篇
  1969年   101篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
The authors report a rare case of chronic myelogenous leukemia (CML) in which the Ph1 clone disappeared after remission induction of lymphoid crisis. A 58-year-old man was admitted to our hospital because of fever in July 1988. The white cell count was elevated. Bone marrow aspirate showed hypercellularity with myeloid hyperplasia. In the chromosomal analysis, Ph1 chromosomes were detected in 100% of bone marrow cells analysed. Diagnosis of CML was made and treatment was initiated with recombinant interferon-alpha 2a. Hematological remission without cytogenetic improvement was achieved. In March 1990 he developed lymphoid crisis with proliferation of CD10-positive cells. The chromosomal analysis revealed additional abnormalities including, 45, X, -Y, t(9;22) (q34;q11), +1, -8. With vincristine 0.6 mgX4, pirarubicin 15 mgX4, dexamethasone 40 mgX4 therapy complete remission was obtained. In December 1990 the Ph1 positive clone completely disappeared judging from normal karyotypes in the chromosomal analysis and the disappearance of M-bcr gene rearrangement.  相似文献   
83.
A case of intracranial arterial vasospasm caused by pituitary apoplexy after head trauma is reported. In this case, pituitary apoplexy was secondary to head trauma, and the vasospasm was thought to be due to subarachnoid hemorrhage from a pituitary tumor. No such case has previously been reported in the literature.  相似文献   
84.
Bone scintigraphy was performed in 17 patients with previously known lung metastases of osteosarcoma. 99Tcm-MDP uptake was observed in all primary bone lesions but lung metastatic lesions were positive in only six patients (35%). 99Tcm-MDP uptake by lung metastases was significantly correlated with bone and osteoid formation in the metastatic lesions and preoperative serum ALPase values. These clinical observations were confirmed by using nude mice transplanted with human lung metastatic osteosarcoma. 99Tcm-MDP scintigraphy appears to be useful for detecting lung metastases of osteosarcoma only in a selected group of patients.  相似文献   
85.
86.
A case of a 19-year-old male with leiomyosarcoma of the prostate is reported. He visited our hospital with the chief complaint of urinary retention in December, 1983. Following overall examination, needle biopsy of the prostate gland was performed with the suspicion of sarcoma. Histology of the prostate revealed leiomyosarcoma. Two courses of combined chemotherapy were given, but the tumor continued to enlarge. The patient died in April, 1984, 5 months after the appearance of the first symptom.  相似文献   
87.
88.
We investigated the effects of mild and non-lethal ischemic insult on neuronal death following subsequent lethal ischemic stress in various brain regions, using a gerbil model of bilateral cerebral ischemia. Single 10-min ischemia consistently caused neuronal damage in the hippocampal CA1, CA2, CA3 and CA4, layer III/IV of the cerebral cortex, dorsolateral part of the caudoputamen and ventrolateral part of the thalamus. On the other hand, in double ischemia groups, 2-min ischemic insult 2 days before 10-min ischemia exhibited significant protection in the CA1 and CA3 of the hippocampus, the cerebral cortex, the caudoputamen and the thalamus. Five-min ischemic insult 2 days before 10-min ischemia also showed protective effect in the same areas as those of 2-min ischemia except for the CA1 region of the hippocampus, while 1-min ischemic insult exhibited no protective effect in any brain regions. In the immunoblot analysis, both 2- and 5-min ischemia caused increased synthesis of heat shock protein 72 (HSP 72) in the hippocampus, but 1-min ischemia did not. The present study demonstrated that the ‘ischemic tolerance’ phenomenon was widely found in the brain and also suggested that ischemic treatment severe enough to cause HSP 72 synthesis might be needed for induction of ‘ischemic tolerance’.  相似文献   
89.
To examine the effects of transient hyperprolactinemia on in vitro fertilization and embryo transfer, 61 cycles in 50 euprolactinemic ovulatory women with irreparable tubal diseases were stimulated with clomiphene (CC) alone or CC and human menopausal gonadotropin followed by human chorionic gonadotropin (hCG). Serum prolactin (PRL) increased after hCG administration with peak values of 45.4 +/- 4.2 ng/ml on the day of laparoscopic oocyte aspiration. The highest serum estradiol (E2) concentration was found on the day before PRL peak and serum progesterone (P) began to increase after hCG injection concomitant with the PRL rise. The group having 50 ng/ml or more of PRL (34 cycles) had significantly higher levels of E2 during preovulatory and early luteal phase compared to those of the group having less than 50 ng/ml of PRL (27 cycles) but there was no significant difference between the P levels in the two groups. In the higher PRL group 72 (62.1%) of 116 collected oocytes were fertilized and 6 (20.0%) conceived. In the lower PRL group 45 oocytes (58.4%) of 77 were fertilized and 3 (12.5%) became pregnant. These data suggest that elevated serum PRL concentrations may have no effect on fertilization of oocytes in vitro or embryonic development.  相似文献   
90.
The 2-deoxy-D-[1-14C]glucose ([14C]DG) method was used to examine the effects of the relatively selective sigma ligand 1,3-di-o-tolylguanidine (DTG) on cerebral metabolism in freely moving rats. Each animal received an i.p. injection of DTG (0.2, 1, or 5 mg/kg) or normal saline 20 min prior to the infusion of [14C]DG. DTG induced dose-dependent changes in local cerebral glucose utilization (LCGU) in several motor and limbic structures. Most structures showed increases in LCGU, with a maximum effect at 1 mg/kg. The most profound increases in LCGU were observed in brain regions that are rich in sigma receptors. These included cerebellar and related nuclei (interpositus, lateral and medial cerebellar n., vestibular n., olivary n.), ambiguus n., superior colliculus (superior layers), hippocampus (CA2, CA3, DG), n. basalis of Meynert interpeduncular n., and the substantia nigra pars compacta and pars reticulata. No significant decreases in glucose utilization were observed at any dose. Although the areas affected by DTG are similar to those previously reported for other sigma ligands, future studies employing a range of doses for additional selective sigma ligands must be carried out in order to confirm whether these changes in LCGU were sigma-mediated.  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