全文获取类型
收费全文 | 8265篇 |
免费 | 482篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 265篇 |
妇产科学 | 129篇 |
基础医学 | 1160篇 |
口腔科学 | 230篇 |
临床医学 | 702篇 |
内科学 | 1897篇 |
皮肤病学 | 126篇 |
神经病学 | 654篇 |
特种医学 | 382篇 |
外国民族医学 | 3篇 |
外科学 | 1501篇 |
综合类 | 189篇 |
一般理论 | 1篇 |
预防医学 | 573篇 |
眼科学 | 96篇 |
药学 | 396篇 |
中国医学 | 6篇 |
肿瘤学 | 383篇 |
出版年
2022年 | 53篇 |
2021年 | 139篇 |
2020年 | 89篇 |
2019年 | 101篇 |
2018年 | 146篇 |
2017年 | 138篇 |
2016年 | 103篇 |
2015年 | 146篇 |
2014年 | 174篇 |
2013年 | 244篇 |
2012年 | 323篇 |
2011年 | 374篇 |
2010年 | 217篇 |
2009年 | 200篇 |
2008年 | 316篇 |
2007年 | 387篇 |
2006年 | 344篇 |
2005年 | 332篇 |
2004年 | 327篇 |
2003年 | 316篇 |
2002年 | 292篇 |
2001年 | 294篇 |
2000年 | 257篇 |
1999年 | 253篇 |
1998年 | 125篇 |
1997年 | 124篇 |
1996年 | 101篇 |
1995年 | 74篇 |
1994年 | 75篇 |
1993年 | 57篇 |
1992年 | 139篇 |
1991年 | 127篇 |
1990年 | 151篇 |
1989年 | 162篇 |
1988年 | 136篇 |
1987年 | 148篇 |
1986年 | 137篇 |
1985年 | 147篇 |
1984年 | 121篇 |
1983年 | 98篇 |
1982年 | 46篇 |
1980年 | 60篇 |
1979年 | 96篇 |
1978年 | 65篇 |
1977年 | 57篇 |
1975年 | 52篇 |
1974年 | 63篇 |
1973年 | 51篇 |
1972年 | 64篇 |
1970年 | 48篇 |
排序方式: 共有8775条查询结果,搜索用时 15 毫秒
11.
Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy 总被引:5,自引:3,他引:2
下载免费PDF全文
![点击此处可从《Canadian Medical Association journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J M Moutquin P R Garner R F Burrows E Rey M E Helewa I R Lange S W Rabkin 《Canadian Medical Association journal》1997,157(7):907-919
OBJECTIVE: To provide Canadian physicians with comprehensive, evidence-based guidelines for the nonpharmacologic management and prevention of gestational hypertension and pre-existing hypertension during pregnancy. OPTIONS: Lifestyle modifications, dietary or nutrient interventions, plasma volume expansion and use of prostaglandin precursors or inhibitors. OUTCOMES: In gestational hypertension, prevention of complications and death related to either its occurrence (primary or secondary prevention) or its severity (tertiary prevention). In pre-existing hypertension, prevention of superimposed gestational hypertension and intrauterine growth retardation. EVIDENCE: Articles retrieved from the pregnancy and childbirth module of the Cochrane Database of Systematic Reviews; pertinent articles published from 1966 to 1996, retrieved through a MEDLINE search; and review of original randomized trials from 1942 to 1996. If evidence was unavailable, consensus was reached by the members of the consensus panel set up by the Canadian Hypertension Society. VALUES: High priority was given to prevention of adverse maternal and neonatal outcomes in pregnancies with established hypertension and in those at high risk of gestational hypertension through the provision of effective nonpharmacologic management. BENEFITS, HARMS AND COSTS: Reduction in rate of long-term hospital admissions among women with gestational hypertension, with establishment of safe home-care blood pressure monitoring and appropriate rest. Targeting prophylactic interventions in selected high-risk groups may avoid ineffective use in the general population. Cost was not considered. RECOMMENDATION: Nonpharmacologic management should be considered for pregnant women with a systolic blood pressure of 140-150 mm Hg or a diastolic pressure of 90-99 mm Hg, or both, measured in a clinical setting. A short-term hospital stay may be required for diagnosis and for ruling out severe gestational hypertension (preeclampsia). In the latter case, the only effective treatment is delivery. Palliative management, dependent on blood pressure, gestational age and presence of associated maternal and fetal risk factors, includes close supervision, limitation of activities and some bed rest. A normal diet without salt restriction is advised. Promising preventive interventions that may reduce the incidence of gestational hypertension, especially with proteinuria, include calcium supplementation (2 g/d), fish oil supplementation and low-dose acetylsalicylic acid therapy, particularly in women at high risk for early-onset gestational hypertension. Pre-existing hypertension should be managed the same way as before pregnancy. However, additional concerns are the effects on fetal well-being and the worsening of hypertension during the second half of pregnancy. There is, as yet, no treatment that will prevent exacerbation of the condition. VALIDATION: The guidelines share the principles in consensus reports from the US and Australia on the nonpharmacologic management of hypertension in pregnancy. 相似文献
12.
The modified dorsal lithotomy position is excellent for radical pelvic operations. Use of modified Krauss arm supports as stirrups, along with pneumatic devices that intermittently compress the legs, significantly reduces postoperative morbidity in patients who undergo operations in this position. 相似文献
13.
14.
15.
Guochuan Tsai Hsien-Yuan Lane Pinchen Yang Mian-Yoon Chong Nicholas Lange 《Neuropsychopharmacology》2004,55(5):452-456
BACKGROUND: Hypofunction of N-methyl-D-aspartate glutamate receptor had been implicated in the pathophysiology of schizophrenia. Treatment with D-serine or glycine, endogenous full agonists of the glycine site of N-methyl-D-aspartate receptor, or D-cycloserine, a partial agonist, improve the symptoms of schizophrenia. N-methylglycine (sarcosine) is an endogenous antagonist of glycine transporter-1, which potentiates glycine's action on N-methyl-D-aspartate glycine site and can have beneficial effects on schizophrenia. METHODS: Thirty-eight schizophrenic patients were enrolled in a 6-week double-blind, placebo-controlled trial of sarcosine (2 g/d), which was added to their stable antipsychotic regimens. Twenty of them received risperidone. Measures of clinical efficacy and side effects were determined every other week. RESULTS: Patient who received sarcosine treatment revealed significant improvements in their positive, negative, cognitive, and general psychiatric symptoms. Similar therapeutic effects were observed when only risperidone-treated patients were analyzed. Sarcosine was well-tolerated, and no significant side effect was noted. CONCLUSIONS: Sarcosine treatment can benefit schizophrenic patients treated by antipsychotics including risperidone. The significant improvement with the sarcosine further supports the hypothesis of N-methyl-D-aspartate receptor hypofunction in schizophrenia. Glycine transporter-1 is a novel target for the pharmacotherapy to enhance N-methyl-D-aspartate function. 相似文献
16.
17.
18.
19.
S Ovroutski V Alexi-Meskishvili P Ewert J-H Nürnberg R Hetzer P E Lange 《European journal of cardio-thoracic surgery》2003,23(3):311-316
OBJECTIVE: Single ventricle palliation is rarely performed in adults and the results are less optimal than in children. In this article we analyze our experience with the modified Fontan operation in this age group. METHODS: Data of 15 consecutive patients with single ventricle with a mean age of 26 (range 16-38) years, who underwent Fontan operation between 3/92 and 1/2000 were retrospectively analyzed. Five patients had previously had an aortopulmonary shunt in childhood and two patients had previously received a bi-directional cavopulmonary shunt as adults. Eleven patients were preoperatively in NYHA class III and four in class II. The main factors for the selection of the patients before surgery were well-developed pulmonary arteries with lower lobe index 120+30 mm/m(2), pulmonary artery pressure <18 mmHg, good cardiac function and enddiastolic systemic ventricular pressure <12 mmHg. The lateral tunnel Fontan operation (LTFO) was performed in ten patients and extracardiac Fontan operation (ECFO) in five. A fenestration 4-5 mm in size was constructed in all patients with LTFO and in three of five patients with ECFO. RESULTS: There was one intraoperative and one late death (total mortality 13%). The mean extubation time and hospital stay were 24 h and 21 days, respectively. Severe postoperative complications were observed in three patients (20%). Two LTFO patients out of a total of eight patients (53%) with perioperative arrhythmias received a permanent pacemaker due to bradyarrhythmia. During the median follow-up of 5.0 (range 2.3-10.1) years, four patients developed arrhythmias; one of them had new onset bradyarrhythmia after LTFO and required permanent pacemaker implantation. The median postoperative oxygen saturation was 93% (range 90-98%). NYHA class improved significantly in 12 survivors. Cardiac catheterization (0.5-4 years postoperatively, n=12) showed excellent Fontan hemodynamics in all patients. CONCLUSIONS: The modified Fontan operation can be performed in adults with acceptable early and midterm mortality and morbidity and leads to either complete or marked relief of cyanosis and enhanced exercise tolerance in all survivors. Postoperative arrhythmias are one of the main drawbacks but the incidence of arrhythmias after ECFO seems to be lower. The long-term follow-up has yet to be established. 相似文献
20.
Giedd Jay N.; Snell John W.; Lange Nicholas; Rajapakse Jagath C.; Casey B. J.; Kozuch Patricia L.; Vaituzis A. Catherine; Vauss Yolanda C.; Hamburger Susan D.; Kaysen Debra; Rapoport Judith L. 《Cerebral cortex (New York, N.Y. : 1991)》1996,6(4):551-559
Brain magnetic resonance images (MRI) of 104 healthy childrenand adolescents, aged 418, showed significant effectsof age and gender on brain morphometry. Males had larger cerebral(9%) and cerebellar (8%) volumes (P < 0.0001 and P = 0.008.respectively), which remained significant even after correctionfor height and weight After adjusting for cerebral size, theputamen and globus pallidus remained larger in males, whilerelative caudate size was larger in females. Neither cerebralnor cerebellar volume changed significantly across this agerange. Lateral ventricular volume increased significantly inmales (trend for females), with males showing an increase inslope after age 11. In males only, caudate and putamen decreasedwith age (P = 0.007 and 0.05, respectively). The left lateralventricles and putamen were significantly greater than the rightP = 0.01 and 0.0001, respectively). In contrast, the cerebralhemispheres and caudate showed a highly consistent right greater-than-leftasymmetry (P < 0.0001 for both). All volumes demonstrateda high degree of variability. These findings highlight gender-specificmaturational changes of the developing brain and the need forlarge gender-matched samples in pediatric neuropsychiatric studies. 相似文献