全文获取类型
收费全文 | 1082843篇 |
免费 | 72092篇 |
国内免费 | 1388篇 |
专业分类
耳鼻咽喉 | 15182篇 |
儿科学 | 34773篇 |
妇产科学 | 28826篇 |
基础医学 | 154989篇 |
口腔科学 | 29677篇 |
临床医学 | 95507篇 |
内科学 | 205048篇 |
皮肤病学 | 24560篇 |
神经病学 | 82246篇 |
特种医学 | 43532篇 |
外国民族医学 | 201篇 |
外科学 | 164221篇 |
综合类 | 21752篇 |
现状与发展 | 1篇 |
一般理论 | 264篇 |
预防医学 | 74915篇 |
眼科学 | 24738篇 |
药学 | 86641篇 |
7篇 | |
中国医学 | 2816篇 |
肿瘤学 | 66427篇 |
出版年
2019年 | 7819篇 |
2018年 | 11384篇 |
2017年 | 8997篇 |
2016年 | 10193篇 |
2015年 | 11380篇 |
2014年 | 15446篇 |
2013年 | 22458篇 |
2012年 | 30852篇 |
2011年 | 32619篇 |
2010年 | 19179篇 |
2009年 | 18011篇 |
2008年 | 30271篇 |
2007年 | 32394篇 |
2006年 | 33056篇 |
2005年 | 31387篇 |
2004年 | 30050篇 |
2003年 | 28854篇 |
2002年 | 27841篇 |
2001年 | 60141篇 |
2000年 | 61606篇 |
1999年 | 51038篇 |
1998年 | 12545篇 |
1997年 | 11075篇 |
1996年 | 11079篇 |
1995年 | 10387篇 |
1994年 | 9405篇 |
1993年 | 8900篇 |
1992年 | 37870篇 |
1991年 | 36369篇 |
1990年 | 35816篇 |
1989年 | 34351篇 |
1988年 | 30916篇 |
1987年 | 30037篇 |
1986年 | 28274篇 |
1985年 | 26502篇 |
1984年 | 19232篇 |
1983年 | 16159篇 |
1982年 | 8875篇 |
1979年 | 17077篇 |
1978年 | 11454篇 |
1977年 | 10266篇 |
1976年 | 8889篇 |
1975年 | 10105篇 |
1974年 | 11698篇 |
1973年 | 11338篇 |
1972年 | 10795篇 |
1971年 | 10135篇 |
1970年 | 9285篇 |
1969年 | 8963篇 |
1968年 | 7940篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
171.
Summary Intracavitary application of ultrasound was first performed for diagnostic purposes in 1967; since that time, it has been
more and more widely used. As far as the gastrointestinal tract is concerned, endoscopically controlled ultrasonic probes
provide visualization of the various layers of the intestinal wall. It is therefore possible to describe lesions of the esophagus,
stomach, and the rectum with regard to their nature and depth of infiltration. Furthermore, periesophageal and perigastric
organs can be visualized. It has become evident that endosonography is particularly important for pretherapeutic staging of
tumors of the esophagus, stomach, and rectum. Here prospective comparative studies confirm the superiority of this new diagnostic
procedure when compared to the methods available to date. 相似文献
172.
A K Siriwardena 《European journal of vascular surgery》1990,4(6):649-650
A case of blunt injury to the abdominal aorta is presented. A deceleration injury with seat-belt compression caused dislodgement of atheromatous fragments as emboli from an atherosclerotic aorta. Atherosclerosis is common, and the compulsory wearing of seat-belts may make this injury more frequent. 相似文献
173.
C Niek van Dijk Ben Willem J. Mol Liesbeth S. L. Lim Rene K. Marti Patrick M. M. Bossuyt 《Acta orthopaedica》1996,67(6):566-570
We prospectively enrolled 160 consecutive patients with inversion trauma of the ankle in a diagnostic protocol that included physical examination within 2 days and at 5 days after trauma, arthrography, stress radiography, and ultrasonography. 135 patients had pathological lateral ligament laxity on the later physical examination or lateral ligament rupture diagnosed on arthrography and they were operated on. 122 of these patients had ligament ruptures.
At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.
Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information. 相似文献
At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.
Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information. 相似文献
174.
Aim : The study was designed to determine the effect of computerized nutrition information on consumer food choice in two workplace restaurants, one in which customers had to pay for their lunch and the other providing a free lunch. Methods : Customers entering the restaurants were asked to make selections from the menu on a computer screen. The energy, saturated fatty acids, non-milk extrinsic sugars and non-starch polysaccharide content of the meal selected was displayed graphically in proportion to the dietary reference values. They were given the opportunity to change their selected meal and the composition of all meals was recorded. Results : The nutritional composition of the first meal provoked 16% of customers to make a second selection. The proportion of energy in the first selection had been 31% higher for saturated fatty acids and 23% higher for non-milk extrinsic sugars than the first selection made by people who were satisfied with their first choice. In their second attempt they succeeded in reducing both nutrients to levels similar to those present in the meals selected by people who had been satisfied with their first selection. Customers>> selections for non-starch polysaccharide and energy did not differ between the groups. The main changes made by customers to achieve improved second choices were to omit dishes (44%), add dishes (19%), make changes within a menu category (46%), and make changes from one menu category to another (26%). Conclusion : It was concluded that provision of graphical nutrition information on a computer screen could be used by a subset of the users of both restaurants to enable them to improve their menu selections to a similar composition to that selected by the other people who used the computer system. 相似文献
175.
176.
What is the value of bcl-2 protein detection for histopathologists? 总被引:15,自引:0,他引:15
177.
178.
CT- or sonography-guided biopsy of the liver in the presence of ascites: frequency of complications 总被引:1,自引:0,他引:1
F B Murphy K P Barefield H V Steinberg M E Bernardino 《AJR. American journal of roentgenology》1988,151(3):485-486
The presence of ascites has been considered a contraindication to percutaneous biopsy of the liver. To determine the validity of this assumption, we performed percutaneous biopsies of the liver under CT or sonographic guidance in 28 patients who had ascites and in 28 patients who did not have ascites and compared the complication rates in the two groups. Twenty-two patients (79%) in the group with ascites and 19 patients (68%) in the group without ascites had biopsies to determine the cause or extent of chronic liver disease. The remainder were oncologic patients who had biopsies to determine the cause of a focal hepatic mass. The complication rate in the patients who had ascites (32%) was less than that in the patients who did not have ascites (43%) (the difference did not reach statistical significance, p less than .30). In the ascites group, complications included transient hypotension (five patients), a mild-to-moderate fall in hematocrit (three patients), and a small leak of ascites from the biopsy site (one patient). In the control group, minor complications included transient hypotension (three patients), a mild-to-moderate fall in hematocrit (seven patients), and a small subcapsular hematoma (one patient). One major complication occurred in the control group: a patient required a blood transfusion because of the fall in his hematocrit. We conclude that the complication rate in liver biopsies guided by CT or sonography in the presence of ascites is not higher than similar biopsies done in the absence of ascites. Ascites should not be considered a contraindication for performing such biopsies. 相似文献
179.
S K Malhotra R Predy R Singh B L Gupta R Bhatnagar K Leeuw 《Journal of neuroscience research》1988,19(4):420-7, 472-3
A mouse monoclonal antibody (MAb 6B9, isotype IgM) was raised against autopsy tissue samples from the central nervous system (CNS) of multiple sclerosis (MS) patients. By immunofluorescence microscopy, MAb 6B9 intensely stains most or all cells in fetal rats. However, MAb 6B9 differentially stains various cell types in adult rats. Neurons, ependymal cells, and adrenal chromaffin cells are stained intensely, whereas astrocytes and oligodendrocytes are not stained. The 6B9-reactive antigen (6B9 antigen) is sensitive to periodic acid, but insensitive to treatment with protease, RNase, or hyaluronidase. Results from immunofluorescence microscopy on semithin sections and cultured neuroblastoma cells indicate that 6B9 antigen is intracellular. This is supported by immunoelectron microscopy, where labeling for 6B9 antigen appears in the cytoplasm distinct from any identifiable organelle. Further studies on 6B9 antigen should reveal its chemical nature as well as the significance of developmental changes in its distribution. 相似文献
180.
The amount of endothelial cell loss that occurs to the donor cornea during the trephination process was evaluated in 40 porcine eyes. A vital staining technique (alizarin red S and acid violet 19) was used to quantify the extent of endothelial damage and removal. Two types of corneal punches (Weck and H&I0 were used for trephination. The average amount of endothelial loss from the peripheral cornea was 7.9%, accounting for only a 3% loss of endothelial cells over the total surface area of the corneal button. a comparison of the Weck and H&I corneal punches showed no significant difference (P greater than 0.1) by Student's test for both endothelial cell damage and removal. 相似文献