全文获取类型
收费全文 | 13758篇 |
免费 | 665篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 156篇 |
儿科学 | 279篇 |
妇产科学 | 210篇 |
基础医学 | 1855篇 |
口腔科学 | 539篇 |
临床医学 | 886篇 |
内科学 | 3018篇 |
皮肤病学 | 316篇 |
神经病学 | 1081篇 |
特种医学 | 554篇 |
外科学 | 2212篇 |
综合类 | 96篇 |
预防医学 | 353篇 |
眼科学 | 219篇 |
药学 | 962篇 |
中国医学 | 31篇 |
肿瘤学 | 1698篇 |
出版年
2023年 | 96篇 |
2022年 | 169篇 |
2021年 | 272篇 |
2020年 | 152篇 |
2019年 | 196篇 |
2018年 | 268篇 |
2017年 | 194篇 |
2016年 | 232篇 |
2015年 | 224篇 |
2014年 | 339篇 |
2013年 | 431篇 |
2012年 | 637篇 |
2011年 | 717篇 |
2010年 | 443篇 |
2009年 | 341篇 |
2008年 | 626篇 |
2007年 | 693篇 |
2006年 | 644篇 |
2005年 | 697篇 |
2004年 | 648篇 |
2003年 | 601篇 |
2002年 | 602篇 |
2001年 | 415篇 |
2000年 | 417篇 |
1999年 | 350篇 |
1998年 | 211篇 |
1997年 | 151篇 |
1996年 | 159篇 |
1995年 | 126篇 |
1994年 | 121篇 |
1993年 | 100篇 |
1992年 | 258篇 |
1991年 | 282篇 |
1990年 | 247篇 |
1989年 | 323篇 |
1988年 | 227篇 |
1987年 | 212篇 |
1986年 | 193篇 |
1985年 | 191篇 |
1984年 | 126篇 |
1983年 | 119篇 |
1982年 | 60篇 |
1979年 | 92篇 |
1977年 | 65篇 |
1975年 | 62篇 |
1974年 | 61篇 |
1973年 | 65篇 |
1972年 | 68篇 |
1970年 | 61篇 |
1969年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Kazunori Aizawa Takeshi Hanaoka Hiroki Kasai Kaoru Kogashi Setsuo Kumazaki Jun Koyama Hiroshi Tsutsui Yoshikazu Yazaki Noboru Watanabe Osamu Kinoshita Uichi Ikeda 《Hypertension research》2006,29(2):123-128
The phosphodiesterase-5 (PDE-5) inhibitor, sildenafil, has been reported to produce sustained pulmonary vasodilatation in patients with pulmonary hypertension (PH). Recently, vardenafil, a more potent and selective PDE-5 inhibitor than sildenafil, has been approved for the treatment of erectile dysfunction. However, the long-term effects of oral vardenafil in patients with PH are unknown. We studied five consecutive patients with PH; one with primary pulmonary hypertension, two with chronic pulmonary thromboembolism, one with Eisenmenger syndrome (ventricular septal defect) and one with secondary pulmonary hypertension after a ventricular septal defect closure operation. In an acute hemodynamic trial, vardenafil (5 mg) significantly decreased both the pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) with an increase in cardiac output. In a chronic hemodynamic trial, the maintenance dose of vardenafil (10 to 15 mg) for 3 months significantly decreased the PVR, but not the SVR, with a 20.7% reduction of the PVR/ SVR ratio. Plasma brain natriuretic peptide (BNP) levels were also significantly decreased after 3 months. This pilot study demonstrates that long-term oral vardenafil therapy may be a safe and effective treatment for patients with PH. 相似文献
3.
4.
5.
Hiroto Egawa Koichi Tanaka Mureo Kasahara Yasutsugu Takada Fumitaka Oike Kohei Ogawa Seisuke Sakamoto Koichi Kozaki Kaoru Taira Takashi Ito 《Liver transplantation》2006,12(10):1512-1518
Living donor liver transplantation (LDLT) for patients with portal vein thrombosis (PVT) involves technical difficulty. The aim of this research was to analyze their preoperative diagnosis of PVT, operative procedures, and postoperative courses of patients with preoperative PVT. Thirty-nine patients of 404 adult patients (9.7%) undergoing LDLT in our hospital from 1996 June to 2004 December had PVT at their transplantation. Twenty-nine patients had intractable ascites, 21 had gastrointestinal bleeding, and 18 had encephalopathy. The thrombus was located in the portal trunk in 23, in the portal trunk and superior mesenteric vein (SMV) in 7, and developed into the SMV and the splenic vein in 8. The occlusive grade was partial in 29, and complete in 10 patients. The thrombus was removed by a simple technique, and eversion and/or incision technique, or total removal of the portal vein (PV). The PV was reconstructed with the thrombectomized native PV, with an interposed vein graft, or porto-caval hemitransposition. Advanced PVT had a significant impact on blood loss and hospital mortality. Three out of 10 patients with residual PVT required radiological and/or surgical intervention after transplantation. In conclusion, thorough planning is essential for a successful LDLT outcome for patients with preexisting PVT. 相似文献
6.
T. Akatsu T. Murakami K. Ono M. Nishikawa E. Tsuda S.-I. Mochizuki N. Fujise K. Higashio K. Motoyoshi M. Yamamoto N. Nagata 《BONE》1998,23(6):495-498
Osteoclastogenesis inhibitory factor (OCIF) is a novel secreted protein that inhibits osteoclastogenesis both in vitro and in vivo. In this study, we examined the effects of OCIF on serum calcium (Ca) concentrations in normal mice and in hypercalcemic nude mice carrying tumors associated with humoral hypercalcemia of malignancy. In normal mice, a single intraperitoneal injection of OCIF reduced serum Ca levels in a dose-dependent manner. Significant decrease in serum Ca (by 1.6 ± 0.3 mg/dL, n = 5) was observed 2 h after the injection of OCIF at 20 mg/kg and the hypocalcemic effect continued for up to 12 h. Serum phosphate (Pi) concentrations also decreased in response to OCIF. Urinary excretion of Ca, Pi, and creatinine did not change significantly after injection of OCIF or vehicle. In hypercalcemic, tumor-bearing nude mice, a single intraperitoneal injection of OCIF at 20 mg/kg resulted in a dramatic decrease in serum Ca (maximal decrease 2.8 ± 0.37 mg/dL, n = 11), which continued for up to 24 h. The results suggest that OCIF decreased serum Ca through its inhibitory effect on bone resorption. Furthermore, it is suggested that OCIF has therapeutic potential for the treatment of hypercalcemic conditions such as malignancy-associated hypercalcemia. 相似文献
7.
Experiments were performed on spinalized rats, transected at the Cl level. The intravenous administration of TRH and its analog YM-14673 (N alpha-[(S)-4-oxo-2-azetidinyl) carbonyl]-L-histidyl-L-prolinamide dehydrate) produced marked increases in the amplitude of mono- and polysynaptic reflex potentials and those of the withdrawal flexor reflexes. The effects of YM-14673 were stronger and longer-lasting than those of TRH. The stimulant action of TRH and YM-14673 on the flexor reflexes was not antagonized by prazosin, chlorpromazine, haloperidol or cyproheptadine, suggesting no involvement of the release of catecholamines or serotonin in the stimulant effects of TRH and its analog. Therefore, YM-14673 may be beneficial for the treatment of several spinal motor neuron diseases. 相似文献
8.
9.
10.
R Hattori O Matsuura N Takeuchi J Hashimoto S Ohshima Y Ono S Yamada T Kinukawa K Miyake 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1991,82(5):810-815
As a prospective study on asymptomatic microhematuria, complete urological examinations including cystoscopy, IVP, ultrasound and urinary cytology were performed on 422 patients over 40 years old between January 1987 and December 1988 (group A). The results of group A was compared with that of retrospective study on 266 patients, who had incomplete urological examination between January 1984 and December 1985 (group B). Cystoscopy was performed on 321 patients (87.2%) in group A and on 108 patients (40.6%) in group B. Bladder tumor was found in 10 cases (2.4%) in group A, including 7 cases of male patients (5.7%), but in only 1 case (0.4%) in group B. Since the negative rate of abnormal urinary cytology was 50% and that of abnormal IVP was 90% in 10 cases of bladder tumor in group A, cystoscopy was considered to be an essential examination for the screening of patients with asymptomatic microhematuria over 40 years old patients. 相似文献