全文获取类型
收费全文 | 8122篇 |
免费 | 323篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 203篇 |
妇产科学 | 138篇 |
基础医学 | 880篇 |
口腔科学 | 170篇 |
临床医学 | 476篇 |
内科学 | 1911篇 |
皮肤病学 | 160篇 |
神经病学 | 519篇 |
特种医学 | 430篇 |
外国民族医学 | 1篇 |
外科学 | 1149篇 |
综合类 | 19篇 |
一般理论 | 1篇 |
预防医学 | 277篇 |
眼科学 | 197篇 |
药学 | 795篇 |
中国医学 | 9篇 |
肿瘤学 | 1075篇 |
出版年
2023年 | 41篇 |
2022年 | 63篇 |
2021年 | 160篇 |
2020年 | 85篇 |
2019年 | 99篇 |
2018年 | 134篇 |
2017年 | 123篇 |
2016年 | 126篇 |
2015年 | 133篇 |
2014年 | 185篇 |
2013年 | 244篇 |
2012年 | 386篇 |
2011年 | 415篇 |
2010年 | 260篇 |
2009年 | 205篇 |
2008年 | 399篇 |
2007年 | 434篇 |
2006年 | 399篇 |
2005年 | 438篇 |
2004年 | 440篇 |
2003年 | 384篇 |
2002年 | 418篇 |
2001年 | 218篇 |
2000年 | 265篇 |
1999年 | 249篇 |
1998年 | 127篇 |
1997年 | 108篇 |
1996年 | 91篇 |
1995年 | 73篇 |
1994年 | 64篇 |
1993年 | 54篇 |
1992年 | 150篇 |
1991年 | 139篇 |
1990年 | 149篇 |
1989年 | 149篇 |
1988年 | 136篇 |
1987年 | 130篇 |
1986年 | 120篇 |
1985年 | 128篇 |
1984年 | 89篇 |
1983年 | 51篇 |
1982年 | 36篇 |
1981年 | 32篇 |
1980年 | 31篇 |
1979年 | 49篇 |
1978年 | 30篇 |
1977年 | 22篇 |
1975年 | 24篇 |
1972年 | 20篇 |
1969年 | 34篇 |
排序方式: 共有8505条查询结果,搜索用时 15 毫秒
21.
To evaluate the beneficial effects of heparin on flap survival area, an experimental study was carried out on dorsal flaps in rats. Topical applications of heparin, released from a silicone gel sheet onto the critical area (which generally necrosed without treatment), resulted in an increase in the flap survival area and rate as compared to controls (p < 0.01). When heparin was applied topically but solely to an area proximal to the critical area however, no increase in the survival area resulted. 相似文献
22.
K Takeuchi S Suzuki N Kako M Kobayashi S Takahashi M Sawada T Honma S Iwabuchi K Fukui K Koyama 《The Annals of thoracic surgery》1992,54(2):327-332
The mechanism by which prostacyclin acts to prevent in vivo reperfusion injury is still uncertain. This study was therefore undertaken to assess the effect of a stable prostacyclin analogue (OP 41483-alpha-CD [OP]) on oxygen-derived free radicals after heart-lung transplantation. OP was administered to the heart-lung graft through the pulmonary artery for 25 minutes encompassing the reperfusion process. Free radicals were directly measured by electron spin resonance spectroscopy. The radical intensities of pulmonary venous blood were significantly lower in the OP group than in the control group, suggesting that fewer free radicals were generated in the lungs of the OP group. The cardiac and respiratory function were better in the OP group than in the control group. The lung is the primary source of oxygen free radical attack, and the beneficial action of OP on free radical generation is almost exclusively restricted to the lung and does not apply to the heart. This result suggested that OP probably is effective in inhibiting free radical generation from the endothelium. 相似文献
23.
M S Laskar M H Mahbub Kenjiro Yokoyama Masaiwa Inoue Noriaki Harada 《The European journal of contraception & reproductive health care》2006,11(3):220-227
OBJECTIVE: There might be a difference between non-working and working women in their perception of rights and privileges which may influence their contraceptive behavior. The purpose of this study was to examine contraceptive behavior among non-working and working women in Bangladesh determining associated factors. METHOD: Analysis was based on data from the 1999-2000 Bangladesh Demographic and Health Survey which employs nationally representative sample. RESULTS: The prevalence of current contraceptive use (any method) was 58.2% among non-working women and 65.5% among working women. Both rates are still low for the country. Some factors, such as discussed family planning with husband, husband approves family planning, desire for more children, and husband lives together, were influential determinants of lower contraceptive prevalence among the non-working women. CONCLUSION: The results indicate a necessity for social activities promoting husband-wife communication and women's participation in employment to enhance the use of contraceptives among Bangladeshi women, especially non-working women. 相似文献
24.
25.
We report a 10-year-old Down syndrome patient who developed dystonia, choreoathetosis, dysarthria, and dysphagia beginning with hemiparesis. Cranial computed tomography disclosed bilateral calcification in the globus pallidus which resembled a sign of premature aging. Conversely, the clinical course and magnetic resonance imaging findings resembled those of Hallervorden-Spatz syndrome. 相似文献
26.
Summary Changes occurring in serotonin neurons during hyperthermia-induced convulsions were examined by means of a modified immunohistochemical method. All mice (8–12 weeks of age) exposed to the temperature of 50°C had convulsions, showing a generalized tonic and/or clonic pattern. Immediately after the convulsions, the animals were perfused transcardially with a fixative. A significant reduction in serotonin immunoreactivity was observed in the neostratum (caudate-putamen complex) of the mice which had hyperthermia-induced seizures, while the serotonin immunoreactivity remained unchanged in the neocortex and paleostriatum. These results suggest that serotonin may be an important mediator in the mechanism of hyperthermia-induced convulsions or that the susceptibility of serotonin neurons to a convulsive state is greatest in the neostriatum.Supported in part by Grant No. 86-05 from the National Center for Nervous, Mental and Muscular Disorders (NCNMMD) of the Ministry of Health and Welfare and Grant No. 62770677 from the Ministry of Education, Science and Culture, Japan 相似文献
27.
K Sawada H Yamamoto K Matsumoto H Yago S Suehiro C Tahara H Ishii M Kazama T Abe 《Thrombosis research》1992,65(2):199-209
Changes in the plasma thrombomodulin (TM) level were examined in endotoxin-infused rabbits. The plasma TM level in normal rabbits was 143.8 +/- 8.4 ng/ml (n = 67) and the molecular weight of the major TM was about 55 kd. Endotoxin (lipopolysaccharide, LPS, E. Coli B8:0127) was intravenously infused. LPS infusion increased the plasma TM level dose-dependently between 0.2 mg/kg and 5 mg/kg. When 5 mg/kg LPS was infused, the plasma TM level started to increase immediately and was 2.3 times higher than the control value within 1 hr. The molecular weight of the major TM was about 75 kd. This rapid increase in TM occurred before the decrease in fibrinogen content and the prolongation of prothrombin time. To examine the effect of circulating leukocytes on the TM increase in endotoxin-infused rabbits, 5 mg/kg LPS was infused into rabbits with leukocytopenia induced by X-ray irradiation. The maximum plasma level of TM was significantly lower than in the untreated rabbits given LPS. These data suggest that the increase in plasma TM is caused by LPS-stimulated leukocyte's prior to hemostaseological changes. It is well known that endothelial cells can be injured by stimulated leukocytes, so this increase in plasma TM probably reflects the deterioration of endothelial cells. This deterioration decreases the ability of endothelial cells to inhibit thrombosis, which would, in turn, contribute to the development of disseminated intravascular coagulation in endotoxin-infused rabbits. 相似文献
28.
MRI and SPECT findings in amyotrophic lateral sclerosis 总被引:1,自引:0,他引:1
Summary MRI was performed in 21 patients and single photon emission computed tomography (SPECT) withN-isopropyl-p-123I iodoamphetamine in 16 patients, to visualize upper motor neurone lesions in amyotrophic lateral sclerosis. T2-weighted MRI revealed high signal along the course of the pyramidal tract in the internal capsule and cerebral peduncle in 4 of 21 patients. SPECT images were normal in 4 patients, but uptake was reduced in the cerebral cortex that includes the motor area in 11. 相似文献
29.
Increased accumulation of iodine-123-IMP in the pulmonary inflammatory lesion surrounding a lung cancer 总被引:1,自引:0,他引:1
Masayuki Nakajo Noriaki Uchiyama Yoshiyuki Hiraki Yoshihiko Miyata Atsuhisa Iriki Yasunobu Hirotsu Joeji Wakimoto Yoshimasa Norimatsu 《Annals of nuclear medicine》1988,2(1):49-53
In a patient with primary lung cancer, increased accumulation of I-123-IMP was observed in a pulmonary inflammatory lesion surrounding a lung cancer which was delineated as a photon deficient area. Ga-67-citrate uptake was observed in both the inflammatory and cancerous areas. These findings suggest that I-123-IMP may have the potential to accumulate differently in a variety of pathological conditions of the lung and thus may be a clinically useful lung imaging agent. 相似文献
30.
Hidehito Matsuoka Wataru Nishio Toshihiko Sakamoto Hiroaki Harada Noriaki Tsubota 《European journal of cardio-thoracic surgery》2004,26(3):480-482
OBJECTIVE: To predict accurate morbidity after lung resection using treadmill exercise test. METHODS: A total of 130 patients (108 men and 22 women, with mean age 67.1+/-11.4 years (range, 34-78 years)) of 1129 patients underwent standard lobectomy were performed both treadmill exercise test and spirometry preoperatively. We measured maximum oxygen uptake/body weight (VO2max/BW) and change in arterial blood oxygen pressure from rest to symptom-limited maximum loading (delta aPaO2) and calculated exercise-induced hypoxemia (delta PaO2/delta VO2/BW), and retrospectively compared these parameters for patients with and without complications. RESULTS: There were five patients with severe postoperative complications, including three requiring use of a respirator, two with home oxygen therapy. %Vital capacity, VC (%, 80.2+/-13.2 vs. 92.5+/-20.9, P=0.026), delta PaO2 (Torr, -29.3+/-4.3 vs. -13.2+/-10.8, P=0.0004), VO2max/BW (ml/min/kg, 16.5+/-2.9 vs. 20.6+/-5.1, P=0.018) and delta PaO2/delta VO2/BW (Torr/ml/min/kg, -1.98+/-0.26 vs. -0.57+/-0.47) were significantly associated with worse outcome. All the five patients with complications had delta PaO2/delta VO2/BW<-1.7. CONCLUSIONS: Treadmill exercise testing is a good method for assessment of cardiopulmonary reserve. Limited resection must be performed if delta PaO2/delta VO2/BW is under -1.7. 相似文献