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   3550篇
  免费   172篇
  国内免费   27篇
耳鼻咽喉   34篇
儿科学   33篇
妇产科学   64篇
基础医学   446篇
口腔科学   59篇
临床医学   218篇
内科学   991篇
皮肤病学   41篇
神经病学   241篇
特种医学   169篇
外科学   569篇
综合类   15篇
预防医学   87篇
眼科学   23篇
药学   293篇
中国医学   6篇
肿瘤学   460篇
  2023年   25篇
  2022年   40篇
  2021年   88篇
  2020年   59篇
  2019年   53篇
  2018年   78篇
  2017年   60篇
  2016年   65篇
  2015年   85篇
  2014年   104篇
  2013年   119篇
  2012年   194篇
  2011年   218篇
  2010年   128篇
  2009年   95篇
  2008年   201篇
  2007年   199篇
  2006年   209篇
  2005年   205篇
  2004年   204篇
  2003年   206篇
  2002年   201篇
  2001年   76篇
  2000年   69篇
  1999年   92篇
  1998年   54篇
  1997年   52篇
  1996年   50篇
  1995年   39篇
  1994年   38篇
  1993年   30篇
  1992年   38篇
  1991年   41篇
  1990年   24篇
  1989年   26篇
  1988年   26篇
  1987年   21篇
  1986年   27篇
  1985年   29篇
  1984年   24篇
  1983年   17篇
  1982年   20篇
  1981年   9篇
  1980年   12篇
  1979年   12篇
  1978年   13篇
  1977年   12篇
  1976年   7篇
  1969年   8篇
  1967年   6篇
排序方式: 共有3749条查询结果,搜索用时 15 毫秒
91.
92.
To elucidate the associations between Lp(a) levels and coronary and aortic atherosclerosis, we performed aortic MRI in 143 patients undergoing coronary angiography. Severity of aortic atherosclerosis was represented as plaque scores. Of the 143 patients, 104 had coronary artery disease (CAD). Thoracic and abdominal aortic plaques were found in 89 and 131 patients. Lp(a) levels increased stepwise with the number of stenotic coronary vessels: 15.7 (CAD(-)), 21.2 (1-vessel), 21.4 (2-vessel), and 22.9 mg/dl (3-vessel) (P<0.05). For aortic atherosclerosis, 143 patients were divided into quartiles by plaque scores. Lp(a) did not differ among quartiles of thoracic plaques: 17.1, 19.0, 23.5, and 21.2 mg/dl (P=NS), whereas Lp(a) increased stepwise with quartiles of abdominal plaques: 17.1, 19.2, 19.1, and 24.0 mg/dl (P<0.05). Lp(a) was an independent factor for CAD and abdominal aortic plaques, but not thoracic plaques. Thus, Lp(a) levels were associated with aortic atherosclerosis, especially in abdominal aorta, as well as coronary atherosclerosis.  相似文献   
93.
94.
Dynamic activity of glia has repeatedly been demonstrated, but if such activity is independent from neuronal activity, glia would not have any role in the information processing in the brain or in the generation of animal behavior. Evidence for neurons communicating with glia is solid, but the signaling pathway leading back from glial-to-neuronal activity was often difficult to study. Here, we introduced a transgenic mouse line in which channelrhodopsin-2, a light-gated cation channel, was expressed in astrocytes. Selective photostimulation of these astrocytes in vivo triggered neuronal activation. Using slice preparations, we show that glial photostimulation leads to release of glutamate, which was sufficient to activate AMPA receptors on Purkinje cells and to induce long-term depression of parallel fiber-to-Purkinje cell synapses through activation of metabotropic glutamate receptors. In contrast to neuronal synaptic vesicular release, glial activation likely causes preferential activation of extrasynaptic receptors that appose glial membrane. Finally, we show that neuronal activation by glial stimulation can lead to perturbation of cerebellar modulated motor behavior. These findings demonstrate that glia can modulate the tone of neuronal activity and behavior. This animal model is expected to be a potentially powerful approach to study the role of glia in brain function.  相似文献   
95.
A 64-year-old man with a 2-month history of abdominal distension was admitted for transient cerebral ischemic attack. A CT scan revealed massive ascites. Laparoscopy showed multiple whitish nodules on the visceral peritoneum and the omentum. Peritoneal biopsy revealed tumor cells consistent with malignant peritoneal mesothelioma (MPeM). Pemetrexed in combination with cisplatin was administered because it has been reported to be active in patients with MPeM. However his disease progressed. As second-line therapy paclitaxel was tried which yielded a complete response (CR). Eighteen months later he developed abdominal pain of the right upper region where a CT scan showed a mass with surrounding inflammation. As third-line therapy, gemcitabine was administered and again resulted in a CR. He is alive at 3 years from first presenting. Searches for case studies published in medical journals on MPeM were carried out, and 59 cases were analyzed in comparison with this case.  相似文献   
96.
An 85-year-old woman with no history of abdominal surgery complained of abdominal pain and vomiting and was referred to us with a diagnosis of intestinal obstruction a few days later. Upon admission to our facility, she presented with marked abdominal swelling and prominent kyphosis. Because of the kyphosis, most of the dilated bowel was compressing her thoracic cavity. No obvious strangulation or free air was observed via abdominal computed tomography imaging. We attempted decompression using a nasogastric tube, but the symptoms persisted. Surgery was performed 2 days after admission. The origin of the obstruction was a compression of the ileocecal region by the costal arch. The bowel was discolored, and thus surgically excised. There were no major postsurgical complications other than a mild wound infection. Until now, there have been no reports of advanced kyphosis inducing ileus, but there are concerns of an increase in similar cases as society continues to age.  相似文献   
97.
BACKGROUND:Autoantibodies to p53 (anti-p53) are rarely present in the sera of patients with autoimmune diseases or the sera of patients with malignancies.OBJECTIVE:To examine the prevalence of anti-p53 in patients with autoimmune liver disease including autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), AIH/PBC overlap syndrome (AIH/PBC OS) and primary sclerosing cholangitis (PSC), and to determine the clinical significance of anti-p53 in autoimmune liver diseases.METHODS:Forty patients with AIH, 41 patients with PBC, eight patients with AIH/PBC OS and five patients with PSC were enrolled. Anti-p53 and antibodies to double-stranded DNA (anti-ds-DNA) were analyzed using commercially available ELISA kits. Demographic, laboratory and histological data were compared between the AIH groups seropositive and seronegative for anti-p53.RESULTS:Six of 40 (15.0%) patients with AIH and four of eight (50.0%) patients with AIH/PBC OS were positive for anti-p53. One of 41 (2.4%) patients with PBC was also positive for anti-p53, but all five patients with PSC were negative, indicating a significantly higher prevalence of anti-p53 in patients with AIH or AIH/PBC OS compared with patients with PBC. None of the AIH patients positive for anti-p53 progressed to hepatic failure or relapsed after immunosuppressive treatment. Titres of anti-ds-DNA in patients with AIH and AIH/PBC OS significantly correlated with titres of anti-p53 (r=0.511; P=0.0213).CONCLUSION:The emergence of anti-p53 is likely to be useful for discriminating AIH or AIH/PBC OS from PBC and helpful for predicting favourable prognoses in patients with AIH. DNA damage may trigger the production of anti-p53 in patients with AIH or AIH/PBC OS.  相似文献   
98.
99.
100.

Introduction

The management of a large splenorenal shunt is important because it affects recipient outcome, particularly in living donor liver transplantation.

Methods

To manage large splenorenal shunts in living donor liver transplantation, we diverted superior mesenteric vein and splenic portal vein blood flow by ligation at the root of the splenic portal vein.

Result

This procedure was applied for five patients in whom superior mesenteric vein blood flow had been completely stolen by a splenorenal shunt preoperatively. Postoperative course was excellent in all cases.

Conclusion

This technique completely prevents morbidity related to large splenorenal shunts after living donor liver transplantation.  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