全文获取类型
收费全文 | 18416篇 |
免费 | 1216篇 |
国内免费 | 343篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 237篇 |
妇产科学 | 369篇 |
基础医学 | 2406篇 |
口腔科学 | 431篇 |
临床医学 | 1977篇 |
内科学 | 2043篇 |
皮肤病学 | 89篇 |
神经病学 | 3501篇 |
特种医学 | 799篇 |
外科学 | 1675篇 |
综合类 | 2234篇 |
一般理论 | 2篇 |
预防医学 | 1492篇 |
眼科学 | 74篇 |
药学 | 1722篇 |
10篇 | |
中国医学 | 626篇 |
肿瘤学 | 223篇 |
出版年
2024年 | 36篇 |
2023年 | 251篇 |
2022年 | 562篇 |
2021年 | 756篇 |
2020年 | 685篇 |
2019年 | 589篇 |
2018年 | 553篇 |
2017年 | 605篇 |
2016年 | 621篇 |
2015年 | 663篇 |
2014年 | 1243篇 |
2013年 | 1244篇 |
2012年 | 1047篇 |
2011年 | 1275篇 |
2010年 | 958篇 |
2009年 | 967篇 |
2008年 | 947篇 |
2007年 | 888篇 |
2006年 | 836篇 |
2005年 | 655篇 |
2004年 | 554篇 |
2003年 | 514篇 |
2002年 | 406篇 |
2001年 | 318篇 |
2000年 | 299篇 |
1999年 | 230篇 |
1998年 | 186篇 |
1997年 | 192篇 |
1996年 | 145篇 |
1995年 | 140篇 |
1994年 | 158篇 |
1993年 | 124篇 |
1992年 | 108篇 |
1991年 | 110篇 |
1990年 | 106篇 |
1989年 | 77篇 |
1988年 | 80篇 |
1987年 | 75篇 |
1986年 | 64篇 |
1985年 | 95篇 |
1984年 | 86篇 |
1983年 | 46篇 |
1982年 | 69篇 |
1981年 | 59篇 |
1980年 | 63篇 |
1979年 | 46篇 |
1978年 | 46篇 |
1977年 | 48篇 |
1976年 | 34篇 |
1975年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Joachim H?chel D?rte Lehmann Claudia Fehrenberg Volker Unger David A Groneberg Christian Grosse-Siestrup 《Nephrology, dialysis, transplantation》2003,18(9):1748-1754
BACKGROUND: The isolated perfused canine kidney has been established as a valid model for conducting both renal physiology and transplantation research. This model is of particular importance for developing new strategies to improve graft function after renal transplantation. In the present study, a newly developed method using isolated haemoperfused porcine kidneys was adapted for use in canine kidneys. In contrast to haemoperfusion, synthetic perfusion media can be standardized and can prevent the initiation of blood-mediated reperfusion reactions. Thus, an additional aim was to determine whether blood could be replaced by synthetic cell-free perfusion solutions. METHODS: Canine kidneys (n = 30) were harvested from donors euthanized in veterinary practices for causes unrelated to the present study. The kidneys were isolated and perfused with autologous blood or cell-free synthetic electrolyte buffer (Tyrode solution). During perfusion, we monitored renal perfusate flow (RPF), glomerular filtration rate (GFR), electrolyte and glucose reabsorption, oxygen consumption and urine concentration. RESULTS: Changes in perfusion medium did not affect the RPF. In contrast, GFR, urine concentration and oxygen consumption were significantly higher, whereas fractional excretion of sodium and glucose were significantly lower in blood- than in Tyrode-perfused kidneys. CONCLUSIONS: This system offers a simple model for studying whole-organ functional alterations after acute renal ischaemia. Renal function indicators were below values reported during in vivo physiological conditions. These functions were better conserved when kidneys were perfused with autologous blood than with Tyrode. 相似文献
82.
83.
Laparoscopic colposuspension is one of many new operations for treating female urinary stress incontinence. With initially
reported success rates similar to those of the traditional open procedure, it appears to combine the advantages of laparoscopy
(such as minimal invasiveness and quicker return to normal activities) with the effectiveness of the standard procedure. Different
methods and approaches are used, but endoscopic suture techniques remain difficult and time-consuming. The use of endostapling
devices for fixation of alloplastic material has been a tempting alternative. We present a case during which laparoscopic
colposuspension was performed using staples and mesh. Incontinence did not improve, and the patient suffered severe chronic
pain for 18 months postoperatively. Removal of the alloplastic material and traditional abdominal resuspension led to complete
cure. 相似文献
84.
Temporal stability of lipid responses to acute psychological stress in middle-aged men 总被引:3,自引:0,他引:3
The purpose of this study was to establish the temporal stability of lipid responses to acute psychological stress. Eighteen men were tested twice an average of 16.2 months apart in identical laboratory reactivity protocols. Total cholesterol, triglycerides, high- and low-density lipoprotein-cholesterol, plasma volume, heart rate, and blood pressure were assessed during rest, serial subtraction, and speech. After correction for changes in plasma volume, significant elevations were recorded for all variables during the speech task, but fewer variables showed changes during the serial subtraction task. Strong intersession associations were found when considering levels of the variables during baseline and stress (rs≥58). Correlations for the change scores ranged from .36 to .52 for the atherogenic lipids and from .39 to .87 for the cardiovascular variables. Little evidence was found for stability of plasma volume changes. There is moderate to high temporal stability of the atherogenic lipids when considering rest and stress levels and small to moderate temporal stability when considering change scores. 相似文献
85.
Acquired immunodeficiency syndrome (AIDS) is a serious disease that has special concern for the health care provider. AIDS has continued to grow despite control efforts. As the disease infectivity period remains lengthy, and the heterosexual population is affected to a greater degree, the level of anxiety has also risen despite educational endeavours. Many fears and anxieties have been associated with AIDS patients by health care workers. The reduction of stress, perceived risk and discomfort following educational efforts have been supported in past research. Educational programmes will need to be given for current health care workers at all levels as well as nursing students. Future nurses must be prepared to meet this challenge. This study was conducted using a convenience sample of nursing students at a university in western United States. Its purpose was to assess any changes that occurred in state anxiety following an educational presentation. Spielberge's State-Trait Anxiety Inventory was used as the measurement instrument. Some anxiety levels were significantly reduced. 相似文献
86.
本文报道2例肠梗阻和1例有机磷农药中毒患者出现暂时性高血糖症。该3例患者均无糖尿病史,因有重度失水,经大量补液纠正失水后血糖迅速恢复正常。口服葡萄糖耐量试验正常。作者认为非糖尿病患者可因重度失水而致应激性高血糖症。 相似文献
87.
F. Wappler N. Roewer A. Köchling H. Braune T. Reissinger J. Schulte am Esch 《Intensive care medicine》1996,22(8):809-812
Malignant hyperthermia (MH) in humans is usually triggered by volatile anaesthetics and depolarizing muscle relaxants. However, other factors or drugs (e.g. cresol) are thought to induce MH. We report a case of fulminant MH associated with a ketoacidotic diabetic coma. After therapy for diabetic coma with insulin (containing the preservative cresol) and electrolyte solutions was started, the patient complained of increasing myalgia, developed a high fever and respiratory and metabolic acidosis and lost consciousness. MH was treated immediately with dantrolene; the patient recovered within 14 days. Five months later the patient was diagnosed as MH-susceptible by the in vitro caffeine and halothane contracture test. This case supports the assessment that MH and diabetes are associated diseases and that cresol could possibly trigger MH. Furthermore, therapy with dantrolene has been demonstrated to the beneficial in the treatment of MH associated with diabetic coma. 相似文献
88.
1986年10月至1990年3月,先后在贵州省EHF野鼠型疫区遵义、安顺两县和家鼠型疫区凯里市选点,监测丘陵地区自然状态下影响EHF流行的主要因素,连续两年的逐月监测结果表明,人间流行的强度、临床表现和流行特征的不同与主要宿主动物种类、密度和带病毒率以及病原体的毒力和型别有关。 相似文献
89.
Reinstatement of alcohol-seeking by priming injections of alcohol and exposure to stress in rats 总被引:10,自引:5,他引:5
A. D. Lê B. Quan W. Juzytch P. J. Fletcher N. Joharchi Y. Shaham 《Psychopharmacology》1998,135(2):169-174
Previous studies using a reinstatement procedure have found that acute reexposure to the self-administered drug and exposure
to footshock stress reinstate heroin and cocaine seeking after prolonged drug-free periods. Here we tested whether these findings
generalize to alcohol-taking behavior. Male rats were initially allowed to consume alcohol in a two-bottle choice procedure
(water versus alcohol) for 30 min/day for 36 days. Rats were then trained for 60 min/day in operant chambers to press a lever
for the drug (0.13 ml of 12% w/v of an alcohol solution) for up to 55 days. After stable drug-taking on a fixed-ratio-3 schedule
of reinforcement was obtained, lever pressing for alcohol was extinguished by terminating drug delivery for 4–9 days. Reinstatement
of drug seeking was then determined after non-contingent priming injections of alcohol (0.24 and 0.48 g/kg; given IP and orally)
or exposure to intermittent footshock stress (5 and 15 min; 0.8 mA). Priming injections of alcohol produced a modest dose-dependent
reinstatement of drug seeking, whereas footshock stress potently reinstated extinguished alcohol seeking. In contrast, similar
parameters of footshock failed to reinstate extinguished sucrose-taking behavior in rats previously trained to lever press
for sucrose pellets. These findings extend previous reports on reinstatement of cocaine and heroin seeking by a footshock
stressor and by priming drug injections. It also appears that the reinstatement procedure provides an appropriate methodology
to study relapse to alcohol-taking behavior in the drug-free state.
Received: 9 April 1997 / Final version: 1 August 1997 相似文献
90.
The locomotor stimulant effects of sustained administration of a potent and selective dopamine (DA) D-2 receptor agonist, [+]-4-propyl-9-hydroxynaphthoxazine (PHNO), in rats were assessed 24 h a day during 12 h light-dark cycles. PHNO was administered continuously with subcutaneous implants of Alzet osmotic minipumps (5 g/h), for 12 h a day with modified osmotic minipumps (5 g/h), or by daily injections (15 g, SC). Tolerance was observed to occur only with 24 h continuous infusions and only during the light period. The other treatment regimens produced sensitization of the locomotor response. Daytime tolerance to continuous infusions of PHNO was reversed following reversal of the light-dark cycle. A normally arousing stimulus also reversed (temporarily) daytime tolerance. The present results indicate that the temporal pattern of administration of DA agonists, the phase of the circadian cycle and environmental stimuli associated with arousal are important determinants of the behavioral consequences of long-term treatment. 相似文献