全文获取类型
收费全文 | 2290593篇 |
免费 | 175057篇 |
国内免费 | 3347篇 |
专业分类
耳鼻咽喉 | 32113篇 |
儿科学 | 77645篇 |
妇产科学 | 63464篇 |
基础医学 | 333631篇 |
口腔科学 | 63157篇 |
临床医学 | 208273篇 |
内科学 | 449731篇 |
皮肤病学 | 49726篇 |
神经病学 | 182162篇 |
特种医学 | 88334篇 |
外国民族医学 | 898篇 |
外科学 | 337853篇 |
综合类 | 49103篇 |
现状与发展 | 4篇 |
一般理论 | 890篇 |
预防医学 | 183195篇 |
眼科学 | 51756篇 |
药学 | 169588篇 |
8篇 | |
中国医学 | 4100篇 |
肿瘤学 | 123366篇 |
出版年
2018年 | 23976篇 |
2017年 | 18184篇 |
2016年 | 19937篇 |
2015年 | 22847篇 |
2014年 | 31600篇 |
2013年 | 48484篇 |
2012年 | 66392篇 |
2011年 | 70758篇 |
2010年 | 41577篇 |
2009年 | 39881篇 |
2008年 | 67128篇 |
2007年 | 71955篇 |
2006年 | 71828篇 |
2005年 | 70198篇 |
2004年 | 68098篇 |
2003年 | 65554篇 |
2002年 | 64053篇 |
2001年 | 104981篇 |
2000年 | 108165篇 |
1999年 | 91827篇 |
1998年 | 25797篇 |
1997年 | 23268篇 |
1996年 | 23907篇 |
1995年 | 22600篇 |
1994年 | 21256篇 |
1993年 | 19789篇 |
1992年 | 73279篇 |
1991年 | 71897篇 |
1990年 | 69830篇 |
1989年 | 67243篇 |
1988年 | 62166篇 |
1987年 | 61198篇 |
1986年 | 57658篇 |
1985年 | 55032篇 |
1984年 | 41689篇 |
1983年 | 35612篇 |
1982年 | 20987篇 |
1981年 | 19159篇 |
1979年 | 38357篇 |
1978年 | 27591篇 |
1977年 | 23167篇 |
1976年 | 21684篇 |
1975年 | 23314篇 |
1974年 | 27802篇 |
1973年 | 27204篇 |
1972年 | 25398篇 |
1971年 | 23444篇 |
1970年 | 22039篇 |
1969年 | 20522篇 |
1968年 | 18963篇 |
排序方式: 共有10000条查询结果,搜索用时 625 毫秒
981.
B L Bower D Picus M E Hicks M D Darcy E S Rollins M A Kleinhoffer P J Weyman 《Journal of vascular and interventional radiology : JVIR》1990,1(1):107-112
Retained biliary stones remain a common clinical problem in patients after surgery. Since 1984, the authors have used choledochoscopy in the treatment of suspected retained biliary stones in 75 patients. These procedures were performed in the radiology department with use of local anesthesia supplemented by an intravenously administered sedative and analgesic. A 15-F flexible fiberoptic choledochoscope was used. Fifty-one of the 75 patients were treated as outpatients. Treatment was successful in 74 of 75 patients; in one patient, intrahepatic stones were not completely removed. Electrohydraulic lithotripsy was used to fragment calculi in 11 patients (15%). Biopsies were performed in four patients (5%). Five minor complications occurred; three required overnight admission. Choledochoscopic-assisted removal of retained biliary calculi is a highly effective and safe procedure. Advantages over standard fluoroscopic stone removal include the ability to directly visualize and fragment adherent or impacted stones and visualize noncalculous filling defects, such as air bubbles, mucus, and biliary tumors. 相似文献
982.
983.
A E van der Merwe F J Mattheyse M Bedford P D van Helden D J Rossouw 《Burns : journal of the International Society for Burn Injuries》1990,16(3):193-197
Cultured keratinocytes were used as allografts on burn wounds in two patients. In both patients successful covering of the wounds was obtained. DNA fingerprinting of the epidermis covering the wounds 21 days later showed that the cultured keratinocytes were replaced by the patients' cells. 相似文献
984.
Primary extraosseous osteogenic sarcoma of the mediastinum: clinical, pathologic, and radiologic correlation 总被引:1,自引:0,他引:1
R W Tarr T Kerner B McCook D L Page E P Nance J J Kaye 《Southern medical journal》1988,81(10):1317-1319
We have presented a rare case of primary involvement of the anterior mediastinum by osteogenic sarcoma in which CT was useful in demonstrating calcium within the mass, and in distinguishing the mass from surrounding bony structures. Although rare, extraosseous osteogenic sarcoma should be included in the differential diagnosis of a calcified anterior mediastinal mass. 相似文献
985.
Rapid reorganization of adult rat motor cortex somatic representation patterns after motor nerve injury. 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J N Sanes S Suner J F Lando J P Donoghue 《Proceedings of the National Academy of Sciences of the United States of America》1988,85(6):2003-2007
The potential for peripheral nerve injury to reorganize motor cortical representations was investigated in adult rats. Maps reflecting functional connections between the motor cortex and somatic musculature were generated with intracortical electrical stimulation techniques. Comparison of cortical somatotopic maps obtained in normal rats with maps generated from rats with a facial nerve lesion indicated that the forelimb and eye/eyelid representations expanded into the normal vibrissa area. Repeated testing from an electrode placed chronically in the motor cortex showed a shift from vibrissa to forelimb within hours after facial nerve transection. These comparatively quick changes in motor cortex representation pattern suggest that synaptic relations between motor cortex and somatic musculature are continually reshaped in adult mammals. 相似文献
986.
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
987.
M Parry-Billings B Leighton G D Dimitriadis J Bond E A Newsholme 《Biochemical pharmacology》1990,40(5):1145-1148
The effects of physiological and pathological concentrations of glucocorticoids were investigated using the glucocorticoid antagonist RU486 and the synthetic glucocorticoid dexamethasone, respectively. The effects of these treatments on the concentrations of glutamine and other amino acids in skeletal muscle and plasma and on the rates of release of glutamine and alanine from incubated preparations of skeletal muscle of the rat were investigated. Dexamethasone treatment increased the concentration of glutamine and the rate of release of this amino acid from incubated soleus muscle preparations. This treatment decreased the concentration of glutamine in both gastrocnemius and EDL muscles, but was without effect on the rate of glutamine release from EDL muscles. In contrast, administration of the glucocorticoid antagonist RU486 decreased the rate of glutamine release from muscle. It is concluded that glucocorticoids have marked effects on the metabolism of glutamine by skeletal muscle per se and that these hormones may be important in the control of the rate of glutamine release from muscle in both physiological and pathological conditions. 相似文献
988.
In experiments on albino rats it was established that three administrations of indomethacin in a dose of 0.01 g/kg body weight induced a severe damage of the liver characterized by disturbances of hepatocytic membranes, bile-producing and protein-producing functions of the liver, an enhancement of lipid peroxidation, a decrease of reduced glutathione pool. Antioxidants (tocopherol acetate, essentiale, legalon, flacumin) limit manifestations of indomethacin, hepatotoxicity, as a result of which tha functional-biochemical disorders in the liver show up to a lesser degree. During the combined use of antioxidants in indomethacin-induced lesions of the liver their hepatoprotective activity increases. 相似文献
989.
PCP and related compounds inhibit 3H-mazindol binding to the cocaine receptor on dopamine transporters. The relative potencies of these compounds are such that some of the behavioral effects of PCP could be related to its action at the cocaine receptor; however, the affinity of PCP at the cocaine site (Ki = 1.59 microM) is less than its affinity at its own receptor (Ki about 0.12 microM). More data will be needed to conclusively implicate the cocaine receptor in the action of PCP. 相似文献
990.
J Combe P Poinsard J Besancenot G Camelot F Cattin J F Bonneville T Moulin J L Henlin J L Chopard L Cotte 《Annals of vascular surgery》1990,4(6):558-562
Free-floating clots of the extracranial internal carotid artery are generally considered as surgical emergencies. This retrospective study analyzes six free-floating clots diagnosed by arteriography. Three of these patients had a fixed stroke while the other three had an evolving stroke. Three patients had antecedent ocular or hemispheric transient ischemic attacks. The causes of free-floating clots in the internal carotid artery were atheromatous stenosis in two cases, ulcerated plaque in three cases, and carotid artery dissection in one. All six patients were seen late, approximately 15 hours after their neurologic accident. They were treated with intravenous heparin over a two to five week period. Repeat arteriograms demonstrated complete clot lysis in four instances, while partial lysis was seen in one case. Moderate extension of thrombus occurred in one case only. No further neurologic complications were noted during the treatment by heparin. As indicated by follow-up arteriographic findings, secondary surgery was performed for major carotid lesions and residual clots in five cases. The free-floating thrombus syndrome of the carotid artery should not be considered as a surgical emergency when discovered late in the wake of an acute neurologic accident. 相似文献