全文获取类型
收费全文 | 13758篇 |
免费 | 1223篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 109篇 |
儿科学 | 352篇 |
妇产科学 | 367篇 |
基础医学 | 1964篇 |
口腔科学 | 530篇 |
临床医学 | 1629篇 |
内科学 | 2985篇 |
皮肤病学 | 104篇 |
神经病学 | 1140篇 |
特种医学 | 575篇 |
外科学 | 1646篇 |
综合类 | 256篇 |
一般理论 | 8篇 |
预防医学 | 1560篇 |
眼科学 | 158篇 |
药学 | 863篇 |
中国医学 | 4篇 |
肿瘤学 | 740篇 |
出版年
2021年 | 182篇 |
2020年 | 114篇 |
2019年 | 179篇 |
2018年 | 188篇 |
2017年 | 138篇 |
2016年 | 179篇 |
2015年 | 187篇 |
2014年 | 322篇 |
2013年 | 424篇 |
2012年 | 612篇 |
2011年 | 684篇 |
2010年 | 376篇 |
2009年 | 308篇 |
2008年 | 643篇 |
2007年 | 576篇 |
2006年 | 616篇 |
2005年 | 585篇 |
2004年 | 515篇 |
2003年 | 466篇 |
2002年 | 453篇 |
2001年 | 438篇 |
2000年 | 420篇 |
1999年 | 404篇 |
1998年 | 158篇 |
1997年 | 134篇 |
1996年 | 152篇 |
1995年 | 128篇 |
1994年 | 108篇 |
1992年 | 363篇 |
1991年 | 353篇 |
1990年 | 309篇 |
1989年 | 306篇 |
1988年 | 304篇 |
1987年 | 262篇 |
1986年 | 286篇 |
1985年 | 255篇 |
1984年 | 237篇 |
1983年 | 227篇 |
1982年 | 155篇 |
1981年 | 133篇 |
1980年 | 114篇 |
1979年 | 210篇 |
1978年 | 153篇 |
1977年 | 138篇 |
1976年 | 118篇 |
1975年 | 101篇 |
1974年 | 135篇 |
1973年 | 126篇 |
1972年 | 107篇 |
1968年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 562 毫秒
51.
A V Kiselev O V Morozova G A Gordina V I Tsygankin I S Peterson N N Tupitsyn 《Pediatriia》1991,(11):82-87
Analysis was made of the results of the treatment of 18 children afflicted with lymphoblastic lymphosarcoma, with estimation of predictors influencing the patients' survival (from 1980 to 1986). The most important predictors influencing the 2-year relapse-free survival were found to be the stage, localization of the process, the presence of the symptoms of intoxication and biological activity. The data obtained were used later in the treatment of 160 children during 1986 to 1989. The results of the 2-year survival of this patients' group appreciably differ from those derived before. 相似文献
52.
53.
朱新菊 《世界核心医学期刊文摘》2006,2(5):25-26
背景:图雷特综合征(TS)是一种儿童期发作的,以运动和语音性抽搐为特征的神经精神疾病。1/2~2/3患具有TS发作史的儿童,其抽搐症状在成年期缓解或完全缓解。至少1/3的TS成年患伴有强迫性神经失调(OCD)。目的:阐明TS患儿抽搐和OCD症状的临床过程;确定儿童期基线临床测量结果,是否与将来青春晚期和成人早期症状的严重程度有关。 相似文献
54.
F J Ricou K Murata B H Oh M Kambayashi K L Peterson 《Journal of cardiovascular pharmacology》1992,20(4):671-677
The vasoconstrictive peptide endothelin-1 (ET-1) has been reported to exert a very important positive inotropic effect in vitro. To assess the effect of ET-1 on myocardial contractility in vivo, we compared the effect of intracoronary infusion of 10(-8) M ET-1 (constant coronary blood flow) to that of 10(-8) M dobutamine in 8 swine. ET infusion did not produce changes in segmental shortening (control vs. drug, mean +/- SD): 33.8 +/- 14.3 vs. 30.8 +/- 12.1%, shortening velocity: 10.3 +/- 4.3 vs. 10.7 +/- 4.5 mm/s, or maximum +dP/dt: 1,691 +/- 701 vs. 1,772 +/- 773 mm Hg/s, whereas dobutamine infusion induced an important increase in these measurements; segmental shortening: 36.9 +/- 14 vs. 48.4 +/- 18.8%, shortening velocity: 10.1 +/- 2.6 vs. 14.7 +/- 4.5 mm/s, and maximum +dP/dt: 2,041 +/- 567 vs. 2,389 +/- 765 mm Hg/s (all p less than 0.05). Mean myocardial blood flow assessed by microspheres was unchanged by ET-1 despite a marked increase in coronary artery pressure (88.6 +/- 12.9 vs. 157 +/- 8.8 mm Hg, p less than 0.001). Regional infusion of ET-1 at a dose provoking extensive coronary vasoconstriction does not induce any change in regional or global myocardial function in swine. 相似文献
55.
Effectiveness of a meditation-based stress reduction program in the treatment of anxiety disorders. 总被引:20,自引:0,他引:20
J Kabat-Zinn A O Massion J Kristeller L G Peterson K E Fletcher L Pbert W R Lenderking S F Santorelli 《The American journal of psychiatry》1992,149(7):936-943
OBJECTIVE: This study was designed to determine the effectiveness of a group stress reduction program based on mindfulness meditation for patients with anxiety disorders. METHOD: The 22 study participants were screened with a structured clinical interview and found to meet the DSM-III-R criteria for generalized anxiety disorder or panic disorder with or without agoraphobia. Assessments, including self-ratings and therapists' ratings, were obtained weekly before and during the meditation-based stress reduction and relaxation program and monthly during the 3-month follow-up period. RESULTS: Repeated measures analyses of variance documented significant reductions in anxiety and depression scores after treatment for 20 of the subjects--changes that were maintained at follow-up. The number of subjects experiencing panic symptoms was also substantially reduced. A comparison of the study subjects with a group of nonstudy participants in the program who met the initial screening criteria for entry into the study showed that both groups achieved similar reductions in anxiety scores on the SCL-90-R and on the Medical Symptom Checklist, suggesting generalizability of the study findings. CONCLUSIONS: A group mindfulness meditation training program can effectively reduce symptoms of anxiety and panic and can help maintain these reductions in patients with generalized anxiety disorder, panic disorder, or panic disorder with agoraphobia. 相似文献
56.
Morbidity and death during liver resection in children are due to hemorrhage and the consequences of massive transfusion. To overcome these problems, a new rapid method of blood transfusion was used in four children (8 to 35 months, 8.6 to 13 kg) undergoing extensive hepatic resection for tumor (tumor weight, 440 to 1625 gm). The rapid infusion device consisted of a roller pump and a bubble oxygenator-warmer circuit primed with washed packed red cells resuspended in fresh-frozen plasma and calcium-free balanced salt solution (Plasmalyte). The infusate was warmed, oxygenated, and buffered before it was administered. An average of 5130 ml per patient of this reconstituted blood was infused at an average rate of 122 +/- 45 ml/min, with peak infusion rates sometimes as great as 1 L/min. Cardiac output, pulmonary artery wedge pressure, body temperature, urine output, blood gases, blood chemistries, and coagulation factors remained unchanged during and after these massive transfusions. Blood transfusion at rapid rates required during pediatric liver resection can be accomplished safely if the storage lesion of the bank blood is previously corrected. 相似文献
57.
Blinded clinical evaluation of positron emission tomography for diagnosis of probable Alzheimer's disease. 总被引:5,自引:0,他引:5
W J Powers J S Perlmutter T O Videen P Herscovitch L K Griffeth H D Royal B A Siegel J C Morris L Berg 《Neurology》1992,42(4):765-770
We evaluated the sensitivity and specificity of positron emission tomography for diagnosis of probable Alzheimer's disease under conditions similar to those encountered in the routine clinical practice of nuclear medicine. We obtained tomographic images of regional cerebral blood flow from three groups of subjects: (1) 13 subjects, ages 69 to 84, who had probable Alzheimer's disease diagnosed by validated clinical criteria; (2) 15 subjects, ages 57 to 77, who had Parkinson's disease without dementia; and (3) 11 subjects, ages 65 to 83, who were normal. Three blinded reviewers, who had not previously seen the images, categorized them as normal, bilateral temporoparietal flow defects typical of Alzheimer's disease, or other abnormality. Consensus interpretation demonstrated sensitivity of 0.38 (5/13) and specificity of 0.88 (23/26) for identifying patients with probable Alzheimer's disease. Thus, the criterion of bilateral temporoparietal reduction in cerebral blood flow used in this study did not have sufficient sensitivity to be of clinical value. While other criteria may be developed to improve diagnostic accuracy, clinical utility can be established only by testing for validity in patients with a full spectrum of complicating neurologic and psychiatric conditions for whom diagnosis is uncertain and who are then followed longitudinally to determine clinical outcome or pathologic findings. 相似文献
58.
BACKGROUND. Beginning in 1970, a series of patients with Hodgkin disease were treated at the University of Minnesota, after staging laparotomy, with radiation therapy (RT) for Stage I, II, and IIIA Hodgkin disease. This report is an analysis of the results of the treatment and of treatment modifications. METHODS. From 1970 to 1974, all patients were treated with standard RT. In 1975, an analysis of these patients indicated that patients with large mediastinal mass (LMM) and patients with Stage IIIA spleen-positive (IIIAS+) disease had a higher recurrence rates than patients without these factors. Subsequently, a schema of radical radiation therapy (RRT) was devised, which included low-dose lung RT for patients with LMM and low-dose liver RT for patients with IIIAS+ disease. RESULTS. Analysis of the results of the two treatments indicates that the use of low-dose lung RT in patients with LMM and low-dose liver RT in patients with IIIAS+ Hodgkin disease produced survival and recurrence-free survival results equivalent to those achieved by use of combined modality treatment (CMT) or chemotherapy (CT) alone. CONCLUSIONS. The use of RT with whole lung and liver irradiation for patients with LMM and IIIAS+ Hodgkin disease, respectively, produces results that are equivalent to those of CMT or CT alone with the advantage of a decreased incidence of second malignant neoplasms. In addition, patients who do not respond to initial RT have a greater chance of being saved with chemotherapy than do patients initially treated with CMT of being saved with RT. The authors suggest that radical RT is the treatment of choice for patients with LMM and/or IIIAS+ Hodgkin disease. 相似文献
59.
A Tluczek E H Mischler P M Farrell N Fost N M Peterson P Carey W T Bruns C McCarthy 《Journal of developmental and behavioral pediatrics : JDBP》1992,13(3):181-186
Neonatal screening for cystic fibrosis (CF) has become feasible through analyzing dried blood specimens for immunoreactive trypsinogen (IRT), but the benefits and risks of such a screening program remain to be delineated. This study, a survey of the parents of 104 Wisconsin infants with false-positive IRT tests, showed parents had knowledge deficits about neonatal screening in general, misconceptions about test results, and high levels of anxiety. Parenting behaviors were reportedly unchanged during the usual 3-day waiting period between the news of the abnormal screening test and the diagnostic sweat test. Most, but not all, parents were relieved by negative sweat test results subsequent to the abnormal IRT test. Factors associated with continued parental concern included having less than a high school education and/or having an infant with low Apgar scores. Additionally, those contacted by telephone were more likely to have misinformation and lingering concerns about the presence of CF in their child. 相似文献
60.
DL-2-amino-4-phosphonobutyric acid does not eliminate "ON" responses in the visual system of goldfish.
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
P J DeMarco Jr J Bilotta M K Powers 《Proceedings of the National Academy of Sciences of the United States of America》1991,88(9):3787-3791
DL-2-Amino-4-phosphonobutyric acid (APB) suppresses activity in retinal ON pathways. It is generally assumed that loss of the ON pathway would result in loss of ON responses in the visual system. We tested this assumption by recording activity from the optic nerves of intact goldfish (Carassius auratus) before and after intraocular injection of APB. Whole-nerve responses to increments and decrements of light were compared to electroretinogram responses and to tectal evoked potentials. APB severely reduced the amplitude of the electroretinogram b-wave but left ON and OFF responses from the optic nerve and tectum intact, although decreased in sensitivity. We conclude that APB does not completely eliminate ON responses in the visual system, at least in goldfish. The selectivity and effectiveness of APB must be evaluated in other species before this agent can be relied upon as a useful tool in understanding the roles of ON and OFF pathways in visual function. 相似文献