全文获取类型
收费全文 | 2176610篇 |
免费 | 159241篇 |
国内免费 | 4099篇 |
专业分类
耳鼻咽喉 | 31782篇 |
儿科学 | 73564篇 |
妇产科学 | 62160篇 |
基础医学 | 311951篇 |
口腔科学 | 59433篇 |
临床医学 | 188056篇 |
内科学 | 430676篇 |
皮肤病学 | 46921篇 |
神经病学 | 170416篇 |
特种医学 | 86361篇 |
外国民族医学 | 971篇 |
外科学 | 337275篇 |
综合类 | 48271篇 |
现状与发展 | 2篇 |
一般理论 | 723篇 |
预防医学 | 162303篇 |
眼科学 | 49789篇 |
药学 | 159753篇 |
2篇 | |
中国医学 | 4386篇 |
肿瘤学 | 115155篇 |
出版年
2018年 | 22460篇 |
2017年 | 17198篇 |
2016年 | 18894篇 |
2015年 | 21505篇 |
2014年 | 29924篇 |
2013年 | 46225篇 |
2012年 | 62292篇 |
2011年 | 65996篇 |
2010年 | 40036篇 |
2009年 | 37879篇 |
2008年 | 62874篇 |
2007年 | 67336篇 |
2006年 | 67544篇 |
2005年 | 65923篇 |
2004年 | 63927篇 |
2003年 | 61903篇 |
2002年 | 60506篇 |
2001年 | 101496篇 |
2000年 | 104931篇 |
1999年 | 89223篇 |
1998年 | 24659篇 |
1997年 | 22498篇 |
1996年 | 22596篇 |
1995年 | 21327篇 |
1994年 | 20176篇 |
1993年 | 18864篇 |
1992年 | 70123篇 |
1991年 | 68766篇 |
1990年 | 67049篇 |
1989年 | 64183篇 |
1988年 | 59199篇 |
1987年 | 58218篇 |
1986年 | 54940篇 |
1985年 | 52729篇 |
1984年 | 39447篇 |
1983年 | 33481篇 |
1982年 | 19880篇 |
1981年 | 17716篇 |
1979年 | 36050篇 |
1978年 | 25250篇 |
1977年 | 21346篇 |
1976年 | 20081篇 |
1975年 | 21993篇 |
1974年 | 26048篇 |
1973年 | 25147篇 |
1972年 | 23486篇 |
1971年 | 21457篇 |
1970年 | 20541篇 |
1969年 | 18818篇 |
1968年 | 17614篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
The annual conferences of the European Public Health Associationare a good opportunity to look around in the old continent.I vividly remember the Dresden conference in 2002, which broughtthe European public health community to a city reflecting thegreat and tragic history of Germany. Some of that history, andits effects on German public health, can be experienced firsthand 相似文献
992.
S Amartur Z P Liang F Boada E M Haacke 《Journal of magnetic resonance imaging : JMRI》1991,1(6):721-724
The authors present an improvement to a sigma-filter extrapolation method for the reconstruction of magnetic resonance (MR) images from symmetric discrete Fourier data. By making use of the phase information in the image data, the proposed method can overcome the data inconsistency problem of the original method for handling MR image data with large phase variations, such as those obtained in gradient-echo pulse sequences. Reconstruction results show that its performance is comparable with that of the modified complex sigma-filter method proposed previously to handle the inconsistency problem. However, the new approach has the advantage of reducing computation time by a factor of two with use of a sigma filter applied to real instead of complex images. It is expected that this method will be more practical for use in clinical MR imaging systems. 相似文献
993.
K Mahmood M N Chowdhury E A Ayoola I A Mofleh R S Rashed F Z Faleh 《Tropical gastroenterology》1991,12(4):188-191
Seventy seven antral biopsies were collected from patients attending endoscopy clinic at King Khalid University Hospital, Riyadh, Saudi Arabia during a period of six months between December 1988 to May 1989. Of these 69 (89.6%) showed chronic gastritis as well as Helicobacter-like organisms (HLOs) in the biopsy specimens while 63 (81.8%) of biopsies grew Helicobacter pylori on culture. These findings indicate a good correlation between the histological diagnosis of chronic gastritis and isolation of H. pylori on culture. 相似文献
994.
Spontaneous neuronal hyperactivity in the medial and intralaminar thalamic nuclei of patients with deafferentation pain 总被引:6,自引:0,他引:6
Electrical activity was recorded from single cells in the thalamus of 10 patients with chronic pain associated with deafferentation. Under local anesthesia, these patients underwent either electrode implantation or thalamotomy for treatment of their pain. In eight of the 10 patients, single units were identified as discharging spontaneously in high-frequency, often rhythmic, bursts. The discharges were of two types: short bursts comprised of two to six spikes with a burst frequency of one to four per second; and long trains of 30 to 80 spikes of similar frequency. Reconstruction of electrode trajectories indicated that recordings were made from the region corresponding to the lateral aspect of the mediodorsal thalamic nucleus, the central lateral nucleus, a small part of the central median nucleus, and the parafascicular nucleus. In the eight patients in whom spontaneous neuronal burst activity was exhibited, it was impossible to study activity evoked by natural cutaneous stimulation due to the continuous spontaneous neuronal discharges. Both animal and human studies have suggested that pain related to deafferentation is accompanied by spontaneous hyperactivity in the dorsal horn of the spinal cord and in the ventral posterior thalamic nuclei. The authors present evidence of spontaneous neuronal hyperactivity in the intralaminar thalamic nuclei of patients with pain related to deafferentation. The findings suggest that spontaneous neuronal discharge in patients with pain related to deafferentation is more widespread in the central nervous system than has been previously appreciated. The results have important implications for the surgical treatment of chronic pain. 相似文献
995.
M H Eijgelshoven E R De Kloet D T Van den Berg P L Van Giersbergen 《European journal of pharmacology》1991,205(2):183-189
Evidence indicates that endogenous opioid peptides and glucocorticoids participate in the control of cardiovascular regulation during hemorrhagic shock. In the present study, we investigated a possible interaction between brain opioid peptides and adrenal corticosteroids regarding the control of arterial pressure during hemorrhage. The bleeding volumes required to lower arterial pressure to 80, 60 and 40 mmHg were studied in anesthetized sham-operated (SHAM) and adrenalectomized (ADX) rats. I.c.v. administration of 10 micrograms of naloxone resulted in a significant increase in the bleeding volume required to lower arterial pressure from 60 to 40 mmHg in SHAM animals, whereas no effect of naloxone was observed in ADX animals. Replacement therapy with a 100% corticosterone pellet (100 mg, s.c.), but not with a 12.5% corticosterone pellet (12.5 mg corticosterone and 87.5 mg cholesterol, s.c.), resulted in an effect of naloxone on the bleeding volume in ADX animals. The effect of replacement therapy could be inhibited by i.c.v. pretreatment with the synthetic glucocorticoid receptor antagonist, RU38486 (100 ng). These data suggest that (1) opioid mechanisms are involved in the regulation of blood pressure during hemorrhage, and (2) occupancy of glucocorticoid receptors is required for naloxone to exert its hemodynamic effect during hemorrhagic hypotension in ADX rats. 相似文献
996.
Between May 1984 and January 1988, 18 patients (31 pyeloureteral units) with documented symptomatic cystine stones were treated. Stone size ranged from 5 to 56 mm. in largest diameter, with an average of 21 mm. All pyeloureteral units were treated initially by endourological methods, including ureteroscopy in 10, percutaneous ultrasonic lithotripsy in 9, extracorporeal shock wave lithotripsy (ESWL) in 10 and chemolysis in 2. Of the patients 10 required a combination of these technologies and 2 required an open operation. Of the 31 units 23 were free of stones when the patient was discharged from the hospital. Of 8 patients with retained stones only 3 had fragments greater than 3 mm. in diameter. Based on this experience an algorithm was developed for the urological management of cystine stones. Ureteral calculi may be removed by ureteroscopic techniques or manipulated into the renal pelvis and managed as renal stones. Cystine renal calculi of less than 1.5 cm. may be treated with ESWL monotherapy. Stones of 1.5 to 3 cm. may be treated with ESWL and dissolution, or percutaneous ultrasonic lithotripsy plus dissolution. Staghorn calculi may be treated by percutaneous ultrasonic lithotripsy plus ESWL and/or dissolution for retained fragments. 相似文献
997.
998.
999.
Circulating immune complexes in pre-eclampsia. 总被引:3,自引:0,他引:3
Serum samples from 20 non-pregnant women, 30 women with normal pregnancy and 50 women with pregnancy associated with pre-eclampsia were tested for circulating immune complexes using the polyethyleneglycol precipitation method. A highly significant positive correlation was found between circulating immune complexes and severe pre-eclampsia (BP greater than 140/90 mm Hg, albuminuria greater than 0.25 g/l). In contrast to this the difference in immune complex levels between non-pregnant subject, normal pregnancy cases and patients with mild pre-eclampsia was not statistically significant. A significant positive correlation was found between the level of circulating immune complexes and the severity of albuminuria. These findings suggest that circulating immune complexes, though not seeming to play an aetiological role in pre-eclampsia may very well be involved in its pathogenesis. 相似文献
1000.
F M Burkle 《Emergency Medicine Clinics of North America》1991,9(1):87-105
Existing triage algorithms consider, for the most part, only the primary casualty with physical trauma. Algorithms fail to appreciate the primary, secondary, or tertiary neuropsychiatric casualty. Research advances on neuropsychiatric casualties must link with the mandates of emergency medical services and disaster management to improve triage sensitivity and specificity. Early recognition and management of neuropsychiatric casualties will diminish the potential for long-term consequences. Expanded triage algorithm supplements are proposed to improve the recognition of those victims at risk. 相似文献