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   26982篇
  免费   1254篇
  国内免费   166篇
耳鼻咽喉   158篇
儿科学   485篇
妇产科学   319篇
基础医学   3362篇
口腔科学   496篇
临床医学   1872篇
内科学   7405篇
皮肤病学   467篇
神经病学   2023篇
特种医学   1214篇
外科学   4814篇
综合类   121篇
一般理论   1篇
预防医学   572篇
眼科学   373篇
药学   1660篇
中国医学   51篇
肿瘤学   3009篇
  2023年   171篇
  2022年   323篇
  2021年   584篇
  2020年   341篇
  2019年   430篇
  2018年   548篇
  2017年   425篇
  2016年   482篇
  2015年   569篇
  2014年   702篇
  2013年   810篇
  2012年   1355篇
  2011年   1505篇
  2010年   844篇
  2009年   725篇
  2008年   1265篇
  2007年   1371篇
  2006年   1348篇
  2005年   1327篇
  2004年   1357篇
  2003年   1372篇
  2002年   1378篇
  2001年   729篇
  2000年   686篇
  1999年   708篇
  1998年   384篇
  1997年   315篇
  1996年   260篇
  1995年   224篇
  1994年   228篇
  1993年   169篇
  1992年   530篇
  1991年   406篇
  1990年   442篇
  1989年   425篇
  1988年   400篇
  1987年   365篇
  1986年   347篇
  1985年   376篇
  1984年   236篇
  1983年   210篇
  1982年   107篇
  1979年   185篇
  1978年   107篇
  1977年   120篇
  1975年   95篇
  1973年   101篇
  1971年   91篇
  1969年   99篇
  1968年   107篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Antipsychotics have been found to induce recurrent psychotic episodes lasting minutes to hours, mostly accompanied by oculogyric crisis (OGC). To characterize this side effect, antipsychotic-induced and postencephalitic OGCs that were reported in the literature were compared to find out common characteristics of OGCs and their associated symptoms. Both postencephalitic and antipsychotic-induced OGCs were found to occur late in the day and at regular intervals, and were associated with autonomic symptoms such as profuse sweating, facial flushing, transitory hypertension and difficulty in micturition. They were often associated also with transient psychiatric episodes: visual hallucinations and illusions, auditory hallucinations, delusions, catatonic phenomena, obsessive thoughts and panic attacks. These (OGC) characteristics will be useful in recognizing antipsychotic-induced psychiatric episodes. The associated psychiatric episodes were noted to recur occasionally also without OGC in a few postencephalic cases, and during gradual dose reduction or after a switch to a novel or low-potency antipsychotic in drug-induced cases. These findings suggest that episodes with the OGC characteristics but without OGC per se, may be less severe reactions to antipsychotic medication than those with OGC, and may represent manifestations of subclinical OGC.  相似文献   
3.
4.
To elucidate the effects of teeth on muscle fibers in the tongue during the developmental process, we examined the expression of muscle contractile proteins and the genes for those proteins in normal mice and microphthalmic (mi/mi) mice with impaired tooth eruption. The mice were observed during the growth period, including weaning, which is when feeding movements undergo major changes. Expression of the myosin heavy chain (MyHC)-2a protein, whose contraction speed is relatively slow, disappeared after weaning in normal mice, while it remained in high concentrations even after weaning in mi/mi mice. The presence of MyHC-2a after weaning in mice with no tooth eruption was attributed to a compensation for lack of proper masticatory function and sucking-like movements, as MyHC-2a is necessary for these movements.  相似文献   
5.
A case of cystadenocarcinoma of the liver is reported. The patient was a 73-year-old woman in whom a tumor was detected in the lateral segment of the liver during a health examination. Ultrasonograms and computed tomograms showed a multilocular cystic mass. Magnetic resonance imaging (MRI) showed a multilocular lowintensity mass, including a high-intensity portion and a portal branch compressed by the tumor. MRI with gadolinium showed an enhanced cyst wall. The cystic part of the tumor became smaller and the solid part became larger over a 1-month period, indicating that the tumor was malignant. Subsegmentectomy (S3) was performed and cystadenocarcinoma with cystadenoma was diagnosed by histopathological examination. Identification of changes in the appearance of a tumor should be helpful for the differential diagnosis of cystadenoma and cystadenocarcinoma.  相似文献   
6.
Lithium was administered to a 15-year-old boy who had four episodes of hypersomnia following his recovery from influenza. The episodes lasted about a week and were not associated with depression, hypomania or polyphagia, but were heralded by depersonalization. The episode did not recur during prophylactic lithium administration in the latter half of 1983, but recurred later on three occasions when lithium was discontinued or taken less than prescribed. This finding, together with a few cases reported in the literature, appear to indicate that lithium is potentially effective in preventing hypersomnia even in cases unassociated with affective symptoms. However, its preventive effect may not always be complete, as depersonalization recurred in the present case in March 1985 when the serum lithium level was in the therapeutic range.  相似文献   
7.
PURPOSE: The purpose of this study was to test the functional and histologic fate of costochondral grafts (CG) in temporomandibular joint (TMJ) reconstruction for unilateral ankylosis in the sheep. MATERIALS AND METHODS: Five pure-bred adult Merino sheep were used. Ankylosis was induced by articular damage, disc removal, and placement of a bone graft. At 3 months, a gap arthroplasty was performed with a CG from the thirteenth rib. The sheep were sacrificed 3 months after CG reconstruction. The range of jaw movements were recorded at first operation, at lysis of ankylosis, and at sacrifice. The joints were examined radiologically, macroscopically, and histologically. RESULTS: All sheep showed a decrease in masticatory function, as shown by weight loss and decreased jaw opening, during the ankylosis period. On release, they regained weight and increased the range of jaw movement. Histologically, the joint space was filled with fibrous tissue. However, the partial spaces around the CG head were covered by fibrous tissue and/or fibrous cartilage. CONCLUSIONS: This study shows that, when CGs are used with a gap arthroplasty in a fibrous and bony ankylosed TMJ, masticatory function is restored.  相似文献   
8.
9.
AIMS: To study the time and cost involved in the care of newly registered outpatients with Type 2 diabetes mellitus (DM), compared with patients with hypertension and/or hyperlipidaemia (HTL). METHODS: A total of 313 patients with DM and 58 patients with HTL without diabetes were registered on their first visits to 11 diabetes clinics across Japan. The time and cost involved in their care was recorded over the following 5 months. RESULTS: In the first 3 months, there was an extensive time commitment to both groups. The time spent by physicians was 1.5 times longer for DM than for HTL. The total care time spent by all the care providers for DM was twice that for HTL. The cost of DM care was twice that for HTL, with the cost of medicines excluded. However, half of the cost for DM was for laboratory tests. When these were excluded, and the remaining cost divided by the time spent, the amount for DM was half of that for HTL. Over the 5 months, mean glycated haemoglobin (HbA(1c)) in DM patients improved from 8.0% to 6.5%, and 72% of DM patients achieved the glycaemic target of HbA(1c) < or = 6.5%. CONCLUSIONS: DM care in a diabetes clinic requires a great deal more time and resources than HTL to achieve the best outcome. An educational system for self care, presently lacking in the primary care setting in Japan, would improve glycaemic control for DM patients in the community.  相似文献   
10.
In this study, we used a novel 4-fluid nozzle spray drier to prepare composite microparticles of a water-insoluble drug, flurbiprofen (FP), and a water-soluble drug, sodium salicylate (SS), for the purpose of improving the water solubility of FP. An ethanol solution of FP and an aqueous SS solution were simultaneously introduced through different liquid passages in the 4-fluid nozzle spray drier and then spray-dried. Quantitative elemental analysis suggested that the FP/SS ratio in each composite microparticle was nearly the same as the formulation ratio. We also found that SS and FP exist in a low crystallinity state in the composite particles. Release of FP from dissolved composite microparticles was markedly improved because of an increase in the effective surface area following rapid dissolution of SS. This study shows that it is possible to prepare FP-SS composite microparticles using a 4-fluid nozzle spray drier in single process and that this can improve the ability of FP to dissolve in water.  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