全文获取类型
收费全文 | 2449723篇 |
免费 | 173862篇 |
国内免费 | 6518篇 |
专业分类
耳鼻咽喉 | 34281篇 |
儿科学 | 77165篇 |
妇产科学 | 68863篇 |
基础医学 | 351550篇 |
口腔科学 | 70303篇 |
临床医学 | 223182篇 |
内科学 | 472046篇 |
皮肤病学 | 52267篇 |
神经病学 | 199648篇 |
特种医学 | 92822篇 |
外国民族医学 | 782篇 |
外科学 | 359267篇 |
综合类 | 54763篇 |
现状与发展 | 7篇 |
一般理论 | 868篇 |
预防医学 | 190858篇 |
眼科学 | 56384篇 |
药学 | 183646篇 |
9篇 | |
中国医学 | 5550篇 |
肿瘤学 | 135842篇 |
出版年
2018年 | 25401篇 |
2017年 | 19699篇 |
2016年 | 21476篇 |
2015年 | 24494篇 |
2014年 | 34023篇 |
2013年 | 52544篇 |
2012年 | 70609篇 |
2011年 | 74838篇 |
2010年 | 44003篇 |
2009年 | 41447篇 |
2008年 | 70163篇 |
2007年 | 75275篇 |
2006年 | 75710篇 |
2005年 | 73340篇 |
2004年 | 70537篇 |
2003年 | 67745篇 |
2002年 | 66162篇 |
2001年 | 111457篇 |
2000年 | 114974篇 |
1999年 | 97125篇 |
1998年 | 26848篇 |
1997年 | 24431篇 |
1996年 | 23750篇 |
1995年 | 22462篇 |
1994年 | 21032篇 |
1993年 | 19619篇 |
1992年 | 76397篇 |
1991年 | 74496篇 |
1990年 | 72829篇 |
1989年 | 70088篇 |
1988年 | 65104篇 |
1987年 | 63878篇 |
1986年 | 61184篇 |
1985年 | 58191篇 |
1984年 | 43575篇 |
1983年 | 37247篇 |
1982年 | 22362篇 |
1981年 | 20089篇 |
1979年 | 41022篇 |
1978年 | 29304篇 |
1977年 | 24734篇 |
1976年 | 23322篇 |
1975年 | 25278篇 |
1974年 | 30373篇 |
1973年 | 29620篇 |
1972年 | 27978篇 |
1971年 | 26074篇 |
1970年 | 24523篇 |
1969年 | 23007篇 |
1968年 | 21787篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
A 19 years old, male patient presented with symptoms of smoky urine for 2 weeks, puffiness of face and diminished urine output for 3 weeks associated with occasional lower abdominal and flank pain. Patient's history, clinical findings and available investigations were strongly suggestive of Idiopathic Rapidly Progressive Glomerulonephritis. The patient showed excellent response to glucocorticoid and cytotoxic agent. 相似文献
993.
YS Nagar S Singh V Sawlani L Pal K Dimri P Lal 《Journal of Medical Imaging and Radiation Oncology》2005,49(2):160-162
A rare case of an advanced primary broad ligament carcinoma is discussed, with a review of the literature regarding its incidence, presentation and management. This patient showed a complete response to adjuvant cisplatin-based chemotherapy following panhysterectomy and is presently without any evidence of disease, 15 months after completion of her treatment. 相似文献
994.
Changes in outcome with sphincter preserving surgery for rectal cancer in Korea, 1991-2000. 总被引:3,自引:0,他引:3
S-B Lim S C Heo M R Lee S-B Kang Y J Park K J Park H S Choi S-Y Jeong J-G Park 《European journal of surgical oncology》2005,31(3):242-249
AIM: To report the clinical and oncological data of patients operated on for rectal cancers 3-5 cm from the AV over a 10 year period, including the Sphincter preservation (SP) rate. METHODS: We reviewed medical records of 304 patients with rectal cancers 3-5 cm from the AV who underwent surgical resection from January 1991 through December 2000. The 10 years were divided into three periods based on the introduction of new surgical techniques, specifically, ultralow anterior resection (ULAR) with double stapling in March 1994 and ULAR with coloanal anastomosis in April 1997. The rates of SP, complications and patient survival during these periods were compared. RESULTS: The SP rate increased significantly over the 10 years, from 16.4% in period I (January 1991-February 1994), to 53.0% in period II (March 1994-March 1997), to 86.5% in period III (April 1997-December 2000) (p<0.001). Over time, the age of the patients increased (p=0.004), the length of the distal resection margin became shorter (p=0.005), and the rate of lymph node metastasis increased (p=0.016). The factors significantly influencing SP were the period (p<0.001) and the distance from the AV (p<0.001). Over time, morbidity did not increase, and overall and disease free survival rates did not decrease. In contrast, the overall survival of N2 cases significantly increased over time (p=0.0492). CONCLUSION: Over 10 years, the SP rate in rectal cancers 3-5 cm from the AV was significantly increased by the introduction of the double stapling and coloanal anastomosis techniques. These surgical methods, however, had no effect on morbidity, disease free survival and overall survival rates. 相似文献
995.
Spontaneous regression of a temporal arachnoid cyst 总被引:2,自引:2,他引:0
Surgery is considered to be the standard therapy for arachnoid cysts (ACs). We report the case of a 13-year-old boy in whom a right temporal AC disappeared spontaneously over a period of 10 years. Bulging of the right temporal skull led to the detection of the cyst by computed tomography (CT) scan at the age of 3 years. There were no other clinical symptoms. Subsequent CT scans showed spontaneous regression of the cyst without surgical intervention. The question as to how ACs should be treated is discussed. 相似文献
996.
R Shirane H Shimizu M Kameyama P R Weinstein 《Journal of cerebral blood flow and metabolism》1991,11(6):949-956
A new model of temporary complete cerebral ischemia was developed and tested in 64 rats. With use of microsurgical techniques, both pterygopalatine and external carotid arteries were occluded and the basilar artery was coagulated to reduce potential collateral CBF during ischemia. After this preliminary five-vessel occlusion, temporary global ischemia was induced by occluding the common carotid arteries (CCAs) with microclips. To validate the method, CBF was measured autoradiographically in 24 anatomical regions at death after 5 min of ischemia or after 15 min of ischemia followed by 5 min of reperfusion. Mean arterial blood pressure and arterial blood gases remained stable under controlled endotracheal ventilation and anesthesia (halothane, 70% N2O, and 30% O2) throughout the CBF experiments, except for a 10-15% increase in mean arterial blood pressure for 1-5 min after bilateral CCA occlusion. After the initial five-vessel occlusion, the EEG did not change, and local CBF levels were comparable to those in anesthetized non-surgical controls. When the CCAs were occluded, the EEG flattened rapidly; after 5 min of ischemia, autoradiography showed no detectable blood flow in the forebrain and cerebellum. The local CBF levels measured after 15 min of temporary global ischemia and 5 min of reperfusion demonstrated relatively homogeneous postischemic hyperperfusion; only two of eight rats had several 1- to 3-mm areas of no-reflow. Survival studies showed increasing motor impairment after 10, 15, 30, and 60 min of temporary CCA occlusion. Ischemic neuronal damage was observed histologically in the hippocampus and basal ganglia 24 h after 10 min of temporary ischemia.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
997.
N Gilmore L Cherian W R Klemm 《Progress in neuro-psychopharmacology & biological psychiatry》1991,15(1):91-104
1. This laboratory has previously reported that pretreatment with ganglioside, or even with its constituent, sialic acid (SA), can attenuate certain intoxicating effects of ethanol. It was important to see if these findings could be replicated, particularly by using other measures of ethanol effects. Herein we report that pretreatment with either gangliosides or SA attenuated ethanol-induced decrements in locomotion, nose-poke exploration, and anxiety, but not body temperature. 2. An ethanol dose of 4 gm/kg caused a temperature drop of about 3 degrees C, which was unaffected by any pretreatment. The onset to sleep, however, was delayed an average of 18 or 36 secs in mice pretreated with ganglioside or SA, respectively. Ethanol-only (4 gm/kg) depressed mean cumulative locomotor activity to 31% of normal, whereas the depression was 83% of normal with beef brain ganglioside pretreatment. At 2 gm/kg ethanol alone decreased nose poking in a hole-board test to 29% of normal, but the depression was only 55-63% of normal with SA or ganglioside pretreatment. In a staircase climbing anxiety test, this dose of ethanol had no effect by itself, but both ganglioside and SA pre-treatment increased climbing by 22%. Ethanol did depress rearing to only 11% of normal, whereas rearing was 51 and 99% of normal with SA and ganglioside pretreatment, respectively. In a dark-preference test, ethanol-only caused mice to spend 64% of the time in the light, compared to 31% for controls. Time in the light was only 39 and 46% with ganglioside and SA pretreatment, respectively. 3. Blood levels of ethanol were not significantly affected by pretreatment. 4. When given alone, gangliosides significantly stimulated locomotion and staircase climbing. SA significantly decreased rearing in the staircase test. Both gangliosides and SA tended to increase nose poking, number of crossings in the dark-preference test, and time in a lighted compartment. Thus, it is possible that some of the attenuation of intoxication is attributable to non-specific stimulant properties of gangliosides and SA. 相似文献
998.
Critical illness polyneuromyopathy after artificial respiration. 总被引:3,自引:0,他引:3
A A Op de Coul G A Verheul A C Leyten R L Schellens J L Teepen 《Clinical neurology and neurosurgery》1991,93(1):27-33
Up to now, 71 critically ill patients have been reported with neuromuscular complications after artificial respiration. The authors review the literature and present data of a personal series of 22 patients all suffering from severe flaccid tetraparesis and muscle atrophy, which developed after an average of two weeks artificial respiration. The prognosis was relatively good in those surviving the primary disease. The multiconditional causes are discussed with emphasis on the combination of polyneuropathy and myopathy. Tumor necrosis factor (TNF), a key mediator of sepsis, which also has an influence on muscle and nerves, is mentioned as a possible cause of this illness. 相似文献
999.
Monaural loudness balances were performed by eight normal-hearing subjects to determine the effect of click repetition rate on loudness sensation. Click trains of 500 msec duration were matched in loudness to a standard 500 msec 1000 Hz tone burst presented at three reference loudness levels (70, 80, and 90 phons). Click trains were presented at repetition rates of 11, 31, 51, and 91 clicks per sec. It was found that click trains at faster repetition rates required lower intensities for judgments of equal loudness sensation. This finding was attributed to the process of temporal loudness summation. The magnitude and nature of the temporal summation process as well as the influence of the reference loudness level are discussed. 相似文献
1000.
A study was conducted to evaluate the efficacy of family history factors as screening criteria for childhood hypercholesterolemia. When they were seen for routine care at one of eight office practices, 1005 prepubertal children underwent random serum cholesterol determinations. Parental and grandparental histories of cardiovascular risk factors and atherosclerotic complications prior to 55 years of age were also obtained. Of the initial group, 274 children had total cholesterol levels greater than or equal to 175 mg/dL, and 175 of these children returned for retesting after an overnight fast. A total of 88 children were found to have low-density lipoprotein-cholesterol (LDL-C) values greater than or equal to 90th percentile for age and sex. Maternal and paternal histories of hypercholesterolemia were significantly associated with elevated LDL-C (odds ratio = 7.3 and 2.9, respectively), but had extremely low sensitivities (0.09, 0.15) despite modest positive predictive values (0.42, 0.22). Grandparental histories of sudden death, peripheral vascular disease, and gout were associated with elevated LDL-C, but sensitivities and positive predictive values for all of these factors were less than 0.22. Family history factors most commonly recommended as criteria for cholesterol screening in children did not identify half of all the children with elevated LDL-C and did not selectively identify the most severely affected children. Adding information concerning the presence of childhood obesity did not result in appreciable improvement in LDL-C detection beyond that achieved by family history factors alone. It was concluded that if thorough identification of young children with elevated LDL-C is desired, inclusive population screening rather than a family history-based strategy would be the most effective approach. 相似文献