全文获取类型
收费全文 | 10883篇 |
免费 | 641篇 |
国内免费 | 79篇 |
专业分类
耳鼻咽喉 | 128篇 |
儿科学 | 330篇 |
妇产科学 | 339篇 |
基础医学 | 1296篇 |
口腔科学 | 286篇 |
临床医学 | 959篇 |
内科学 | 2511篇 |
皮肤病学 | 201篇 |
神经病学 | 442篇 |
特种医学 | 462篇 |
外国民族医学 | 1篇 |
外科学 | 1514篇 |
综合类 | 311篇 |
一般理论 | 7篇 |
预防医学 | 726篇 |
眼科学 | 352篇 |
药学 | 987篇 |
中国医学 | 105篇 |
肿瘤学 | 646篇 |
出版年
2023年 | 137篇 |
2022年 | 344篇 |
2021年 | 472篇 |
2020年 | 310篇 |
2019年 | 403篇 |
2018年 | 446篇 |
2017年 | 318篇 |
2016年 | 314篇 |
2015年 | 290篇 |
2014年 | 444篇 |
2013年 | 557篇 |
2012年 | 778篇 |
2011年 | 793篇 |
2010年 | 477篇 |
2009年 | 378篇 |
2008年 | 578篇 |
2007年 | 585篇 |
2006年 | 484篇 |
2005年 | 454篇 |
2004年 | 403篇 |
2003年 | 337篇 |
2002年 | 301篇 |
2001年 | 152篇 |
2000年 | 137篇 |
1999年 | 143篇 |
1998年 | 100篇 |
1997年 | 87篇 |
1996年 | 91篇 |
1995年 | 83篇 |
1994年 | 67篇 |
1993年 | 54篇 |
1992年 | 77篇 |
1991年 | 76篇 |
1990年 | 85篇 |
1989年 | 80篇 |
1988年 | 91篇 |
1987年 | 83篇 |
1986年 | 85篇 |
1985年 | 59篇 |
1984年 | 45篇 |
1983年 | 29篇 |
1982年 | 28篇 |
1981年 | 28篇 |
1980年 | 30篇 |
1979年 | 35篇 |
1978年 | 19篇 |
1977年 | 36篇 |
1976年 | 28篇 |
1975年 | 19篇 |
1970年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
M. O. Hassan O. T. Al Shafie W. J. Johnston 《Clinical physiology and functional imaging》1993,13(5):519-523
Summary. Eleven normotensive diabetics with noninsulin-dependent diabetes mellitus (NIDDM) (mean age 52.5 SD 8.2 years) and 11 controls (mean age 47.4 SD 8.9 years) had their ambulatory blood pressure and heart rate recorded non-invasively by the Oxford Medilog System in standard hospital conditions. The results were averaged as hourly means of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), and heart rate (HR) for the 24-h period and similarly for the ‘awake’ period (14.16 h) and the ‘asleep’ period (8–10 h). Hourly means for diabetics and controls showed no differences in blood pressure and heart rate over the 24 h. During sleep, control subjects showed a significant drop in SBP (P < 0.001), DBP (P < 0.001), MAP (P < 0.001) and HR (P < 0.001). However, this nocturnal dip in blood pressure could not be demonstrated in the diabetic group. Blood pressure variability was significantly increased in diabetics compared to controls during waking hours (P < 0.01). These results indicate that in noninsulin-dependent diabetics during sleep there is loss of the nocturnal dip of BP seen in normal subjects, and they have increased BP variability. These may be contributing factors to the development of hypertension and the accelerated target organ damage (TOD) seen in diabetes., 相似文献
22.
23.
M. Q. Hassan S. A. Hussain M. A. Zaki N. Z. Alsharif S. J. Stohs 《Basic & clinical pharmacology & toxicology》1995,77(6):407-411
Abstract: The effects of uraemias and antioxidant therapy for 40 days with vitamin A, vitamin C and vitamin E on blood and erythrocyte sulfhydryl (glutathione, GSH) content and on erythrocyte glutathione-S transferase (GST), glutathione reductase (GSR) and glutathione peroxidase activities were studied in six uraemic patients maintained on haemodialysis. In addition, the effect of antioxidant therapy on erythrocyte lipid peroxidation was determined, and erythrocyte haemoglobin content was measured. Uraemic patients in dialysis exhibited significant decreases in blood and erythrocyte GSH content as well as significant decreases in the activities of GST, GSR and GSH-peroxidase relative to control subjects. Furthermore, the uraemic patients had elevated erythrocyte malondialdehyde levels. Blood and erythrocyte GSH content from uraemic patients was significantly elevated after 20 days of antioxidant treatment and remained elevated thereafter throughout the remaining 20 days of the study (130% and 173%, respectively). Antioxidant therapy also produced significant increases in GSR and GSH-peroxidase activities after 20 days of treatment which remained relatively constant thereafter. No significant change in GST activity was observed. Erythrocyte malondialdehyde levels, as an index of oxidative tissue damage, exhibited a significant decrease (70%) in the patients after 40 days of antioxidant therapy. A gradual increase in erythrocyte haemoglobin content was observed following treatment of the uraemic subjects (45% at day 40). The results suggest that antioxidant therapy may protect against oxidative stress associated with uraemia. 相似文献
24.
Sherif M. Hassan Frans G.I. Jennekens George Wieneke Henk Veldman 《Neuromuscular disorders : NMD》1994,4(5-6):489-496
Changes in calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) at the motor endplates of botulinum toxin-paralysed rat muscles were investigated using immunohistochemistry. One day following toxin injection, a dramatic increase in CGRP-LI was detected at the motor endplates and within preterminal axons of the soleus and gastrocnemius muscles. The upregulation of CGRP-LI persisted throughout the period during which muscle fibres were paralysed and new neuromuscular junctions were being formed by the growing sprouts. Decline of CGRP-LI at the motor endplates coincided with clinical recovery. Both up- and down-regulation of CGRP-LI took place earlier in the soleus than in the gastrocnemius muscle. Up-regulation of CGRP-LI was also detected in a subpopulation of motor axons in the sciatic nerves and in the spinal motor neurons innervating the paralysed muscles. These results indicate that levels of CGRP are regulated, at least partly, by changes in the target innervation. They also suggest an important role for CGRP in the regenerative processes following muscle paralysis. 相似文献
25.
26.
27.
J C Bousquet A Goze M Hassan E Kieffer P Curet J Grellet 《Journal of ultrasound in medicine》1987,6(1):7-12
Ultrasonographic features of six leiomyosarcomas of the inferior vena cava are described. In most cases, the presentation is typical enough to strongly suggest the histologic diagnosis. The tumor is usually greater than 10 cm long, hypoechoic, heterogeneous. Cystic components can be found. It is sharply demarcated from neighboring organs which are displaced. The mass is located at the very place of the inferior vena cava, the lumen of which is no longer seen. It is fusiform shaped, surprisingly sparing the aorta. Differential diagnosis along with other radiologic examinations, pathologic findings, and prognosis are discussed. 相似文献
28.
Effect of Short-Term Ethanol Feeding on Rat Testes as Assessed by 31P NMR Spectroscopy, 1H NMR Imaging, and Biochemical Methods 总被引:2,自引:0,他引:2
Hassan Farghali Donald S. Williams Judith Gavaler David H. Van Thiel 《Alcoholism, clinical and experimental research》1991,15(6):1018-1023
31P Nuclear magnetic resonance (NMR) spectroscopy and 1H NMR imaging were used to examine the effect of short-term ethanol feeding on the rat testis. Weanling rats were pair-fed for 10 weeks either on ethanol containing liquid diet (36% ethanol of total calories) or a diet in which dextrimaltose was isocalorically substituted for the ethanol of the alcohol-containing diet. In vivo 31P NMR of the testes was used to determine the intratesticular pH and the relative concentrations of various phosphorus-containing metabolites. The integrity of the blood-testes barrier was evaluated using 1H NMR imaging following a gadolinium diethylene tetramine pentaacetic acid derivative (Gd-DTPA) administration as a vascular contrast agent. After the completion of NMR studies, the testis and the liver were freeze-clamped to allow for the assay of their adenosine-5'-triphosphate (ATP) contents. Serum was assayed for its content of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alcohol and testosterone. Ethanol feeding resulted in the following: (a) a reduction in the body weight (p less than 0.05), (b) a reduction in the testicular phosphodiesters (PDE) PDE/ATP ratio (p less than 0.05), (c) an increased change in the testis image intensity difference between pre- and post-iv Gd-DTPA images, (c) a reduction in the testicular and hepatic content of ATP, and (d) increased serum levels of AST and ALT.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
29.
Objectives/Hypothesis: Vocal rehabilitation of patients who have undergone laryngectomy is best accomplished by a tracheoesophageal puncture. Optimal function of the prosthesis requires an adequate stoma. Patients with tracheostomal stenosis require revision of the stoma if vocal rehabilitation is to take place. Revision and tracheoesophageal placement are usually done as two separate procedures. Creating a tracheoesophageal fistula at the time of stomal revision has not been addressed in the literature. Study Design: Prospective analysis and follow-up of 10 patients undergoing simultaneous tracheoesophageal puncture and stomal revision for tracheostomal stenosis between 1991 and 1996. Methods: Ten patients were reviewed. An inferiorly based V-Y advancement flap was used so as not to interfere with the tracheoesophageal puncture. All patients had received radiation prior to revision and tracheoesophageal puncture. Patients were followed for a minimum of 2 years (range, 2–6 y; median, 3 y). Results: All patients maintained an adequate stoma without stenting. Eight of ten patients (80%) developed and maintained good tracheoesophageal speech. Two patients had their speech fistulas removed. There were no intraoperative or postoperative complications. Conclusions: Creation of a tracheoesophageal fistula at the time of stomal revision allows for vocal rehabilitation with a single visit to the operating room. Laryngoscope, 108:1509-1513, 1998 相似文献
30.