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   23471篇
  免费   1369篇
  国内免费   285篇
耳鼻咽喉   469篇
儿科学   302篇
妇产科学   265篇
基础医学   4260篇
口腔科学   554篇
临床医学   1892篇
内科学   4453篇
皮肤病学   888篇
神经病学   1787篇
特种医学   1319篇
外科学   2923篇
综合类   142篇
现状与发展   1篇
一般理论   5篇
预防医学   1054篇
眼科学   449篇
药学   2112篇
中国医学   284篇
肿瘤学   1966篇
  2023年   119篇
  2022年   383篇
  2021年   809篇
  2020年   403篇
  2019年   567篇
  2018年   643篇
  2017年   528篇
  2016年   732篇
  2015年   1082篇
  2014年   1289篇
  2013年   1425篇
  2012年   2155篇
  2011年   2040篇
  2010年   1156篇
  2009年   1039篇
  2008年   1446篇
  2007年   1339篇
  2006年   1141篇
  2005年   1011篇
  2004年   863篇
  2003年   757篇
  2002年   646篇
  2001年   569篇
  2000年   471篇
  1999年   397篇
  1998年   155篇
  1997年   117篇
  1996年   86篇
  1995年   96篇
  1994年   64篇
  1993年   58篇
  1992年   148篇
  1991年   153篇
  1990年   110篇
  1989年   130篇
  1988年   107篇
  1987年   110篇
  1986年   94篇
  1985年   86篇
  1984年   63篇
  1983年   58篇
  1982年   40篇
  1981年   38篇
  1980年   32篇
  1979年   50篇
  1978年   50篇
  1977年   42篇
  1976年   32篇
  1974年   30篇
  1973年   34篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
We considered performing living donor liver transplantation (LDLT) in a larger-size recipient. When the recipient was large-sized, or when the donor liver was severely steatotic or had a right-to-left volume discrepancy. We devised dual living donor liver transplantation (DLDLT) to make up for graft size insufficiency and to secure the donor's safety. However, portal vein thrombosis (PVT) presented a challenge for DLDLT because of the need for intact right and left portal veins for the implantation of both liver grafts. Our 52-year-old male patient with hepatitis B cirrhosis had suffered from repeated esophageal and gastric variceal bleeding and underwent 2 trials of a transjugular intrahepatic portosystemic shunt (TIPS). He developed TIPS occlusion and PVT involving the area just above the spleno-mesenteric confluence to the right and left PV. Also, the right PV orifice was destructed and difficult to isolate because of severe periportal inflammation and neointima growth in the TIPS mesh. The patient's two sons were inadequate for donation because of right-to-left volume discrepancy. Therefore, DLDLT using 2 left lobes was necessary to compensate for graft-size insufficiency and to secure donor safety, and we substituted an intact umbilical portion of recipient's left PV for the destroyed right PV. The patient recovered well, and liver function has been normal for more than a year. In conclusion, the umbilical portion of recipient's left PV can be a useful vascular substitute for the reconstruction of a thrombosed main portal branch in DLDLT.  相似文献   
52.
Needle electromyography (EMG) and determining the motor evoked potential (MEP) of the genioglossus (tongue) are difficult to perform in evaluation of the craniobulbar region in patients with amyotrophic lateral sclerosis (ALS). Needle EMG and MEP determination in the upper trapezius were carried out in 17 consecutive ALS patients. The needle EMG parameters recorded included abnormal spontaneous activity and motor unit action potential morphology. An upper motor neuron lesion was presumed when either response to cortical stimulation was absent, or the central conduction time was delayed (>mean + 2 SD). Of the 12 patients with limb-onset ALS, using needle EMG, 11 were found to have abnormalities in the upper trapezius, and only five in the tongue. Three of the six patients with isolated limb involvement had abnormal MEP findings. In conclusion, electrophysiological studies of the upper trapezius are useful in ALS patients without bulbar symptoms.  相似文献   
53.
The proliferative potential of low-grade astrocytomas was estimated in 47 patients. Each patient received an intravenous infusion of bromodeoxyuridine (BUdR), 150 to 200 mg/sq m, at the time of craniotomy to label cells in deoxyribonucleic acid (DNA) synthesis; the percentage of S-phase cells, or BUdR labeling index (LI), of each tumor was determined immunohistochemically. In 29 patients (60%), the tumors had BUdR LI's of less than 1%, indicating a slow growth rate; only three (10%) of these patients died of recurrent tumor during a follow-up period of up to 3 1/2 years. In contrast, of the 18 patients (40%) whose tumors had BUdR LI's of 1% or more, 12 (67%) had a recurrence and nine died during the same follow-up period. These results show that the proliferative potential, as reflected by the BUdR LI, is an important prognostic factor that separates low-grade astrocytomas into two groups and provides a more scientific rationale for selecting treatment for individual patients.  相似文献   
54.
S S Cho  A G Hyndman 《Brain research》1991,549(2):327-331
Transferrin receptor (TfR) immunoreactivity in the developing chick retina was examined. Immunoreactivity was detectable in the ganglion cells of embryonic day (E) 4 retina. At E9, diffuse TfR immunoreactivity appeared in the outer portion of the inner nuclear layer. Amacrine cells were the most intensely TfR-positive cells in the inner nuclear layer. At E11, the inner segment of photoreceptor cells showed moderate immunoreactivity. With the appearance of the outer segments, positive immunoreactivity was observed in these structures. TfR's developmental distribution in the retina may reflect the developmental and physiological role of transferrin.  相似文献   
55.
56.
BACKGROUND/AIMS: Bamboo joint-like (BJL) appearance is an endoscopic finding characterized by swollen longitudinal folds transversed by erosive fissures or linear furrows on the lesser curvature side of gastric body and cardia. It has been reported to be associated with Crohn's disease (CD). This study was aimed to evaluate the incidence of BJL appearance in Korean patients with CD. METHODS: From January to December in 2005, we performed esophagogastroduodenoscopy (EGD) in patients diagnosed as CD and ulcerative colitis (UC) in our hospital. Non-inflammatory bowel disease (IBD) subjects with upper gastrointestinal symptoms who underwent EGD were consecutively enrolled during the same period. One endoscopist performed all the endoscopic examinations to avoid inter-observer variation. A dye-spraying technique with 0.4% indigocarmine was used to allow the detection of subtle changes during the endoscopic examination. RESULTS: A total of 21 patients with CD (mean age+/-SD, 40+/-15 yr; M/F, 13/8), 28 patients with UC (42+/-15 yr; 21/7), and 685 non-IBD subjects (49+/-14 yr; 354/331) were enrolled. EGD findings in CD patients were gastric erosions (11/21), chronic superficial gastritis (5/21), chronic atrophic gastritis (1/21), duodenal erosions or ulcers (2/21), and normal (2/21). Incidence of BJL appearance was significantly higher in patients with CD (47.6%, 10/21) than others (UC, 3.6%, 1/28; non-IBD, 0.1%, 1/685) (p< 0.0001). Among patients with CD, incidence of BJL appearance was not significantly different according to the sex, status of H. pylori infection, Vienna classification for phenotype, medications or EGD findings. CONCLUSIONS: BJL appearance on the gastric body and cardia can be a diagnostic clue to CD.  相似文献   
57.
Although adenocarcinoma is a well known complication of chronic inflammatory bowel disease, primary gastrointestinal lymphoma occurring in Crohn's disease is rare. A 40-year-old man with 10 year-history of Crohn's disease had multiple longitudinal ulcerative lesions on descending colon in follow-up colonoscopic examination. Microscopic examination of proximal descending colon revealed peripheral T cell lymphoma and other site of the descending colon was consistent with Crohn's disease. The patient reached complete remission of malignant lymphoma after three cycles of combined chemotherapy. He has been well for 10 months with sulfasalazine maintenance therapy but was admitted to the hospital due to spontaneous bowel perforation of ascending colon. Right hemicolectomy was done, but the patient died of post-surgical recurrent mesenteric abscess and sepsis. To the best of our knowledge, this is the first case of Non-Hodgkin's lymphoma complicating Crohn's disease in Korea which was confirmed by immunohistochemical studies.  相似文献   
58.
One hundred nine Korean American community subjects were interviewed regarding their experiences with hwa-byung (HB), a Korean folk illness label commonly used by Koreans with a myriad of physiological and psychological complaints. During these interviews, standard instruments were also used to assess their depressive and somatic symptoms. The results indicated that a relatively high proportion (12%) of the subjects labeled themselves as having suffered from HB. While no apparent sociodemographic differences were found between HB and non-HB subjects, significantly more HB subjects fulfilled the diagnosis of DSM-III major depression and also had previous diagnoses of depression. The HB subjects also had significantly higher scores for the total, depressive, and somatic subscales and 16 of the 20 individual items of the Center for Epidemiologic Studies-Depression Scale. These data confirm previous observations of substantial overlap between HB and DSM-III major depression among Koreans and Korean Americans, and suggest that HB may be a culturally patterned way of expression for Koreans experiencing major depression and related conditions. The clinical and theoretical implications of these findings are also discussed.  相似文献   
59.
60.
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