全文获取类型
收费全文 | 1216篇 |
免费 | 64篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 50篇 |
妇产科学 | 46篇 |
基础医学 | 74篇 |
口腔科学 | 22篇 |
临床医学 | 125篇 |
内科学 | 245篇 |
皮肤病学 | 7篇 |
神经病学 | 62篇 |
特种医学 | 192篇 |
外科学 | 99篇 |
综合类 | 46篇 |
预防医学 | 66篇 |
眼科学 | 6篇 |
药学 | 202篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 48篇 |
出版年
2021年 | 8篇 |
2018年 | 6篇 |
2017年 | 9篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 31篇 |
2011年 | 29篇 |
2010年 | 22篇 |
2009年 | 25篇 |
2008年 | 19篇 |
2007年 | 36篇 |
2006年 | 47篇 |
2005年 | 34篇 |
2004年 | 31篇 |
2003年 | 44篇 |
2002年 | 48篇 |
2001年 | 43篇 |
2000年 | 30篇 |
1999年 | 31篇 |
1998年 | 32篇 |
1997年 | 28篇 |
1996年 | 24篇 |
1995年 | 30篇 |
1994年 | 27篇 |
1993年 | 40篇 |
1992年 | 31篇 |
1991年 | 31篇 |
1990年 | 26篇 |
1989年 | 43篇 |
1988年 | 52篇 |
1987年 | 55篇 |
1986年 | 52篇 |
1985年 | 33篇 |
1984年 | 19篇 |
1983年 | 23篇 |
1982年 | 14篇 |
1981年 | 21篇 |
1980年 | 29篇 |
1979年 | 11篇 |
1978年 | 18篇 |
1977年 | 20篇 |
1975年 | 14篇 |
1974年 | 8篇 |
1973年 | 5篇 |
1972年 | 10篇 |
1971年 | 8篇 |
1970年 | 6篇 |
1969年 | 7篇 |
排序方式: 共有1293条查询结果,搜索用时 562 毫秒
1.
2.
The discriminative stimulus (DS) and subjective effects of d-amphetamine (AMP), phenmetrazine (PMT) and fenfluramine (FFL) were studied in a group of normal healthy adults. Subjects (N=27) were trained to discriminate between placebo and 10 mg AMP (PO). Fourteen of the subjects (discriminators) reliably learned the discrimination, whereas the other 13 did not. Nearly all discriminators labelled AMP as a stimulant, and AMP, relative to placebo, increased ratings of drug liking and general activity level, and produced typical stimulant-like subjective effects, as measured by the Profile of Mood States, the Addiction Research Center Inventory, and a series of visual analog scales. The discrimination accuracy of discriminators increased as a function of hour after drug ingestion, as did analog ratings of how certain subjects were that their discrimination responses were correct. Discriminators were tested with doses of PMT (25 and 50 mg) and FFL (20 and 40 mg) to determine whether the DS properties of these drugs would substitute for those of AMP. Both doses of PMT consistently substituted for AMP, and PMT produced subjective effects very similar to those of AMP. Conversely, neither dose of FFL consistently substituted for AMP, and FFL produced essentially no subjective effects. These findings are consistent with results from discrimination studies with other species, and provide further evidence of the validity of this procedure for studying the DS properties of drugs in humans.
Offprint requests to: L.D. Chait 相似文献
3.
Ten thrombocytopenic patients (platelets < 10–24 × 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/− 11 × 10(9) per L as compared with counts of 16 +/− 7 × 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/− 810 and 10,010 +/− 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/− 9 and 13 +/− 10 × 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/− 1410 and 1520 +/− 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
Perforated colorectal neoplasms: correlation of clinical, contrast enema, and CT examinations 总被引:2,自引:0,他引:2
Hulnick DH; Megibow AJ; Balthazar EJ; Gordon RB; Surapenini R; Bosniak MA 《Radiology》1987,164(3):611-615
Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm. 相似文献
5.
Cysts of the seminal vesicles: diagnosis and management 总被引:1,自引:0,他引:1
6.
7.
A prospective study of post-delivery temperature changes from birth to 24 h, carried out in a busy District General Hospital is reported. The temperature fall after delivery was less than expected and reflected a high level of awareness of the dangers of hypothermia. On the basis of the findings of the survey, hypothermia in the first 24 h can be defined as a rectal temperature of less than 36.4 degrees C. Those babies who did become hypothermic were significantly more likely to be of low birth weight or preterm gestation. 相似文献
8.
OBJECTIVE: To determine the relative benefits and complications of assisted vaginal delivery with metal and silicone rubber vacuum extractor cups. DESIGN: Prospective randomized controlled study. SETTING: A busy referral maternity hospital in Kathmandu, Nepal. SUBJECTS: 101 women were assigned to delivery with the Silc-cup and 98 to delivery with the metal cup. MAIN OUTCOME MEASURES: Success rate at achieving delivery with the assigned instrument and incidence of neonatal trauma. Analysis was by 'intention to deliver' with women remaining in their original group regardless of the eventual mode of delivery. RESULTS: Randomization resulted in two groups of women similar in respect of age, parity, gestation and indication for delivery. The overall success rate was similar for the two instruments (Silc-cup 85% and metal cup 87%). The Silc-cup was more likely to fail if there was excessive caput (seven failures compared with one in the metal cup group). The frequency of clinically significant maternal trauma was low in both groups. There were fewer babies with clinically significant scalp trauma in the Silc-cup group (22%), compared with the metal cup group (37%). CONCLUSIONS: The data indicate a greater tendency for the Silc-cup to fail when excessive caput is present but that metal cups are associated with increased scalp injuries. 相似文献
9.
10.