全文获取类型
收费全文 | 13149篇 |
免费 | 578篇 |
国内免费 | 70篇 |
专业分类
耳鼻咽喉 | 197篇 |
儿科学 | 133篇 |
妇产科学 | 208篇 |
基础医学 | 1461篇 |
口腔科学 | 615篇 |
临床医学 | 913篇 |
内科学 | 3128篇 |
皮肤病学 | 426篇 |
神经病学 | 770篇 |
特种医学 | 484篇 |
外科学 | 2175篇 |
综合类 | 53篇 |
预防医学 | 463篇 |
眼科学 | 399篇 |
药学 | 795篇 |
中国医学 | 31篇 |
肿瘤学 | 1546篇 |
出版年
2022年 | 100篇 |
2021年 | 208篇 |
2020年 | 146篇 |
2019年 | 166篇 |
2018年 | 204篇 |
2017年 | 157篇 |
2016年 | 176篇 |
2015年 | 180篇 |
2014年 | 252篇 |
2013年 | 312篇 |
2012年 | 579篇 |
2011年 | 568篇 |
2010年 | 376篇 |
2009年 | 286篇 |
2008年 | 621篇 |
2007年 | 621篇 |
2006年 | 589篇 |
2005年 | 596篇 |
2004年 | 630篇 |
2003年 | 558篇 |
2002年 | 562篇 |
2001年 | 458篇 |
2000年 | 569篇 |
1999年 | 494篇 |
1998年 | 185篇 |
1997年 | 124篇 |
1996年 | 113篇 |
1995年 | 115篇 |
1994年 | 87篇 |
1993年 | 80篇 |
1992年 | 260篇 |
1991年 | 282篇 |
1990年 | 277篇 |
1989年 | 321篇 |
1988年 | 295篇 |
1987年 | 247篇 |
1986年 | 220篇 |
1985年 | 227篇 |
1984年 | 141篇 |
1983年 | 119篇 |
1979年 | 145篇 |
1978年 | 99篇 |
1977年 | 90篇 |
1976年 | 72篇 |
1975年 | 63篇 |
1974年 | 97篇 |
1973年 | 74篇 |
1972年 | 73篇 |
1970年 | 62篇 |
1969年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
31.
Shinhiro Takeda Kazuhiro Nakanishi Teruo Takano Gen Ishikawa Ryo Ogawa 《Journal of anesthesia》1997,11(2):83-87
Effective gas exchange can be maintained in animals without endotracheal intubation using external high-frequency oscillation
(EHFO). The aim of this study was to evaluate the effect of EHFO in patients with respiratory failure due to severe cardiogenic
pulmonary edema. Seven patients were ventilated with EHFO for 2h at 60 oscillations·min−1, with a cuiras pressure of 36 cmH2O (−26 to +10) and an inspiratory to expiratory ratio of 1:1, with EHFO. Blood gas values and hemodynamic parameters were
measured. Significant increases were noted in cardiac index (2.3±0.5 to 2.5±0.5 l·m−2;P<0.05), stroke volume index (24±7 to 28±8 ml·m−2;P<0.05), and arterial O2 pressure (Pao2) (70±4 to 95±23 mmHg;P<0.01) without a change in pulmonary artery wedge pressure at 1 h after EHFO. The respiratory rate decreased from 28±3 to
22 ±3 breaths·min−1 at 5 min after the termination of EHFO (P <0.01). Arterial CO2 pressure (Paco2) did not, however, decrease. Increased stroke volume without a change in pulmonary artery wedge pressure (preload) suggests
either improved inotropic function of the left ventricle or reduced left ventricular afterload with EHFO. The use of EHFO
may be effective not only for gas exchange but also for left ventricular function in patients with severe cardiogenic pulmonary
edema. 相似文献
32.
A Hiraoka J Ishikawa H Kitayama T Yamagami H Teshima H Nakamura H Shibata T Masaoka S Ishigami F Taguchi 《Bone marrow transplantation》1991,7(2):107-111
We used a thin-sectioning technique for the electron microscopic detection of viral particles within the cells of urinary sediments in three recipients who developed hemorrhagic cystitis after allogeneic bone marrow transplantation. Results of viral cultures of urine and electron microscopic (EM) observations on urinary sediments were consistent in only one recipient. In this recipient, EM observations revealed many viral particles within the cells of urinary sediments with diameter of about 80 nm corresponding to adenovirus, of which type 11 was produced in viral cultures. In one of the other two recipients many viral particles with a mean diameter of 41.6 nm corresponding to papovavirus were observed, but viral cultures using conventional cells were negative. Re-cultures using HEK cells produced polyomavirus BK. EM observation was a clue to the correct diagnosis. In the remaining recipient, no viral particles were observed within the cells of urinary sediments, suggesting the hemorrhagic cystitis to be of non-viral origin, despite a positive result of viral culture. These results suggest that a thin-sectioning technique on the cells of urinary sediments is important for the differential diagnosis between a viral-induced and non-viral hemorrhagic cystitis. 相似文献
33.
Y. Fukuda T. Ishikawa H. Yahata S. Marubayashi K. Dohi 《Transplant international》1992,5(Z1):S596-S598
Since cyclosporin A (CsA), a widely used immunosuppressive drug, strongly suppresses interleukin-2 (IL-2) secretion, it is frequently difficult to estimate T lymphocyte activation in early acute rejection. We found that, when evaluated based on HLA-DQ antigen expression, monocyte activation in the peripheral blood of renal transplantation patients was a very sharp parameter in diagosing acute rejection. All of 16 episodes of early acute rejection, which were relatively easily suppressed by steroid pulse therapy, showed a sharp increase in the proportion of HLA-DQ antigen-positive monocytes (DQ+ mono) and a quick return of DQ+ mono to previous values, along with a fall in serum creatinine levels. Since, however, HLA-DR antigen-positive T lymphocytes (DR +T) were markedly increased over a long period in episodes of therapy-resistant and chronic rejection, their prolonged high value was regarded as a parameter indicative of poor prognosis. 相似文献
34.
35.
36.
Susumu Ishikawa M.D. Akio Ohtaki M.D. Toru Takahashi M.D. Tetsuya Koyano M.D. Yutaka Hasegawa M.D. Satoshi Ohki M.D. Yukitaka Isa M.D. Kennichi Arai M.D. Fumio Kunimoto M.D. Yasuo Morishita M.D. 《Journal of cardiac surgery》1997,12(3):176-179
A bstract The purpose of this study was to assess the efficacy of nasal mask bi-level positive airway pressure (BiPAP) support in managing respiratory failure following cardiovascular surgery. A total of 20 patients requiring postoperative prolonged respiratory support of 72 hours or longer were studied. BiPAP support was used for eight patients (BiPAP group); the other 12 patients were managed using ordinary oxygen mask treatment (control group). The mean age of the BiPAP group and control group was 65 and 58 years of age, respectively. The mean period of postoperative endotracheal intubation of the BiPAP group and control group was 12 ± 5 days and 7 ± 1 days, respectively. Reintubation was necessary in two patients of the control group. The BiPAP group patients required no reintubation. BiPAP support was discontinued within 48 hours in 6 out of 8 patients. The respiratory rates of control group increased (p < 0.1) 24 hours after extubation, however, the respiratory rates of the BiPAP group remained unchanged. The values of the respiratory index of the BiPAP group improved significantly (p < 0.01) after BiPAP management (from 1.5 ± 0.2 to 0.9 ± 0.2). The values of the control group, however, remained unchanged. A-aDO2 and Qs/Qt decreased (p < 0.1) in the BiPAP group. There were no significant differences in central venous pressure or circulatory status between the two groups. In conclusion, BiPAP support is a noninvasive management technique for postoperative respiratory failure and may also prevent prolonged endotracheal intubation. 相似文献
37.
T Ohashi F Yamamoto H Yamamoto H Ichikawa T Shibata Y Shimada T Ishikawa K Kagisaki Y Kumada Y Kawashima 《[Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai》1992,40(11):1998-2004
The effects of potassium in reperfusion solution (RS) and the influence of sodium on this effect were studied. Experimental time course was as followed: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution followed by global ischemia for 33 or 35 min at 37.5 degrees C, 15 min early Langendorff reperfusion with several different potassium concentration modified with Krebs Henseleit Bicarbonate Buffer (KHBB) containing 145 mM and 110 mM sodium and 5 min late reperfusion with KHBB, followed by 20 min working perfusion. Potassium in RS possessed bell shaped dose response nature with optimal concentration of 10 mM in the condition of 145 mM sodium but 6 m in the condition of 110 mM in terms of percent recovery of aortic flow. Although higher potassium reperfusion produced less Creatine Kinase leakage. 相似文献
38.
Y Miyamoto M Nakatani M Ida T Ishikawa N Okazawa M Ariizumi F Tsujimoto K Mizunuma Y Fukuda S Tada 《Journal of clinical ultrasound : JCU》1989,17(5):309-318
Ultrasonography was performed in 45 cases of gastric cancer. Specimens from all 45 cases of gastric cancer were subjects to ultrasonographic study by the water immersion method for comparison with histology. In 32 of these 45 cases in vivo ultrasonographic evaluation was performed prospectively. The overall accuracy rates for the diagnosis of the depth of cancerous invasion were almost 80% in both in vitro and in vivo studies. In vivo ultrasonographic findings agreed well with those from the specimen studies. Ultrasonography was considered to be useful in the diagnosis of gastric malignancies. 相似文献
39.
40.