全文获取类型
收费全文 | 2241篇 |
免费 | 136篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 32篇 |
妇产科学 | 3篇 |
基础医学 | 259篇 |
口腔科学 | 32篇 |
临床医学 | 169篇 |
内科学 | 735篇 |
皮肤病学 | 50篇 |
神经病学 | 214篇 |
特种医学 | 69篇 |
外科学 | 393篇 |
综合类 | 7篇 |
预防医学 | 39篇 |
眼科学 | 39篇 |
药学 | 164篇 |
中国医学 | 5篇 |
肿瘤学 | 147篇 |
出版年
2024年 | 2篇 |
2023年 | 18篇 |
2022年 | 58篇 |
2021年 | 82篇 |
2020年 | 48篇 |
2019年 | 78篇 |
2018年 | 74篇 |
2017年 | 62篇 |
2016年 | 67篇 |
2015年 | 63篇 |
2014年 | 95篇 |
2013年 | 130篇 |
2012年 | 180篇 |
2011年 | 193篇 |
2010年 | 106篇 |
2009年 | 79篇 |
2008年 | 149篇 |
2007年 | 150篇 |
2006年 | 131篇 |
2005年 | 138篇 |
2004年 | 127篇 |
2003年 | 126篇 |
2002年 | 110篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 13篇 |
1998年 | 17篇 |
1997年 | 15篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1975年 | 5篇 |
1971年 | 1篇 |
排序方式: 共有2401条查询结果,搜索用时 0 毫秒
1.
2.
Kazumasa Miyake Atsushi Tatsuguchi Mikiko Tachibana Masanobu Kusunoki Yoko Shinji Kei Shinoki Tetsuro Hiratsuka Kazuhiro Nagata Hitoshi Nishigaki Seiji Futagami Ken Wada Taku Tsukui Toshiro Yoshiyuki Akira Tokunaga Takashi Tajiri Choitsu Sakamoto 《Digestive endoscopy》2004,16(2):172-175
A 52‐year‐old Japanese woman who presented with gastrointestinal (GI) bleeding underwent a proximal gastrectomy for a gastrointestinal stromal tumor (GIST) with a foveolar hyperplasia at the apex of the tumor, 4.5 cm in size, located in the upper body of the stomach. Although GIST are often asymptomatic and are found only incidentally, clinical symptoms such as bleeding, abdominal pain, or obstruction, occasionally lead to a premorbid diagnosis. When submucosal tumors present GI bleeding, the source of the bleeding usually is an ulceration of the mucosa over the tumor. However, in the present study, it was thought that the bleeding originated from the region of foveolar hyperplasia. 相似文献
3.
Impact of portal venous pressure on regeneration and graft damage after living-donor liver transplantation. 总被引:4,自引:0,他引:4
Shintaro Yagi Taku Iida Kentaro Taniguchi Tomohide Hori Takashi Hamada Koji Fujii Shugo Mizuno Shinji Uemoto 《Liver transplantation》2005,11(1):68-75
Several reports claim that portal hypertension after living-donor liver transplantation (LDLT) adversely affects graft function, but few have assessed the impact of portal venous pressure (PVP) on graft regeneration. We divided 32 adult LDLT recipients based on mean PVP during the 1st 3 days after LDLT into a group with a PVP > or = 20 mm of Hg (H Group; n = 17), and a group with a PVP < 20 mm of Hg (L Group; n = 15). Outcome in the H Group was poorer than in the L Group (58.8 vs. 92.9% at 1 year). Peak peripheral hepatocyte growth factor (HGF) during the 1st 2 weeks was higher in the H Group (L: 1,730 pg/mL, H: 3,696 pg/mL; P < .01), whereas peak portal vascular endothelial growth factor (VEGF) level during the 1st week was higher in the L Group (L: 433 pg/mL, H: 92 pg/mL; P < .05). Graft volume (GV) / standard liver volume (SLV) was higher in the H Group (L / H, at 2, 3, and 4 weeks, and at 3 months: 1.02 / 1.24, .916 / 1.16, .98 / 1.27, and .94 / 1.29, respectively; P < .05). Peak serum aspartate aminotransferase, bilirubin levels, and international normalized ratio after LDLT were significantly higher in the H Group, as was mean ascitic fluid volume. In conclusion, early postoperative PVP elevation to 20 mm of Hg or more was associated with rapid graft hypertrophy, higher peripheral blood HGF levels, and lower portal VEGF levels; and with a poor outcome, graft dysfunction with hyperbilirubinemia, coagulopathy, and severe ascites. Adequate liver regeneration requires an adequate increase in portal venous pressure and flow reflected by clearance of HGF and elevated VEGF levels. 相似文献
4.
5.
Yoichi Kikuchi Taku Sakurada Masato Suzuki Tomoyasu Hirano Katsuyuki Kusajima 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(8):375-378
Off-pump coronary artery bypass grafting has become an attractive surgical alternative for myocar-dial revascularization because
of the advantage of myocardial protection and other benefits of patients. However, it is still regarded as a controversial
treatment for the coronary artery disease accompanied by atrial fibrillation (AF). A significant number of patients in need
of coronary revascularization have chronic AF. Although the Cox-Maze III procedure is the gold standard for the surgical treatment
of AF, few of these patients undergo AF operations at the time of their coronary bypass grafting. We report herein a case
of the pulmonary vein isolation to eliminate the AF by means of epicardial radiofrequency ablation combined with 2 vessels
coronary artery bypass grafting on the beating heart with the aid of cardiopulmonary bypass. 相似文献
6.
Okamoto E Watanabe K Hashiba K Inoue T Iwazawa E Momoi M Hashimoto T Mitamura Y 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2002,48(5):495-502
An implantable secondary battery is one of the key components in a total artificial heart system. Because a 2 year cycle life is required, the cycle life of the secondary battery as well as its charge and discharge properties are important parameters for selection of an appropriate battery. We carried out cycle life tests on four kinds of rechargeable batteries (a Ni-MH secondary battery, a Ni-Cd secondary battery, a Li-ion battery with a graphite anode, and a Li-ion battery with a nongraphitizable carbon electrode) to determine their suitability as implanted back-up batteries. Each of the batteries was charge/discharge cycled at 37 degrees C to 39 degrees C using a charge current of 1 C ampere, and they were each fully discharged under either pulsatile discharge loads, which mimicked pulsatile operation, or a nonpulsatile load equivalent to the average of the pulsatile loads. The two Li-ion batteries made by different manufacturers both met the minimum requirement of cycle life of more than 1,500 cycles, considering safety coefficient regardless of the discharge pattern. In addition, the temperature increase of these Li-ion batteries (3 degrees C) was lower than that of Ni-Cd and Ni-MH batteries (15-25 degrees C). Out of these four batteries, the two Li-ion batteries are the most suitable for use in a totally implantable artificial heart system. 相似文献
7.
Fujii K Miyashita T Omata T Kobayashi K Takanashi J Kouchi K Yamada M Kohno Y 《American journal of medical genetics. Part A》2003,(1):65-68
We present the case of a 14-year-old Japanese girl who had both Gorlin syndrome and ulcerative colitis. She had complained of blood stools for 6 months and severe scoliosis from her infancy. Physical examination revealed multiple nevi, palmar and plantar pits, jaw cysts, and calcification of the falx cerebri, leading to the diagnosis of Gorlin syndrome. Total colonoscopy revealed an edematous and spotty bleeding mucosa extending from the anus to the transverse colon. Histological examination was also compatible with ulcerative colitis. Thus, we diagnosed her as having Gorlin syndrome with ulcerative colitis. Gene analysis revealed a mutation, 1247InsT, in the human patched gene (PTCH), resulting in the truncation of PTCH protein. Since Gorlin syndrome and ulcerative colitis are rare disorders in childhood, this association is interesting, suggesting a correlation between the hedgehog signaling and intestinal disorders. 相似文献
8.
Park JW Taube C Swasey C Kodama T Joetham A Balhorn A Takeda K Miyahara N Allen CB Dakhama A Kim SH Dinarello CA Gelfand EW 《American journal of respiratory cell and molecular biology》2004,30(6):830-836
The role of an interleukin (IL)-1 receptor antagonist (IL-1Ra) on the development of airway hyperresponsiveness (AHR) and airway inflammation following acute O(3) exposure in mice was investigated. Exposure of C57/BL6 mice to O(3) at a concentration of 2.0 ppm or filtered air for 3 h resulted in increases in airway responsiveness to inhaled methacholine (MCh) 8 and 16 h after the exposure, and an increase in neutrophils in the bronchoalveolar lavage (BAL) fluid. IL-1beta expression, assessed by gene microarray, was increased 2-fold 4 h after O(3) exposure, and returned to baseline levels by 24 h. Levels of IL-1beta in lung homogenates were also increased 8 h after O(3) exposure. Administration of (human) IL-1Ra before and after O(3) exposure prevented development of AHR and decreased BAL fluid neutrophilia. Increases in chemokine levels in lung homogenates, tumor necrosis factor-alpha, MIP-2, and keratinocyte chemoattractant following O(3) exposure were prevented by IL-1Ra. Inhalation of dexamethasone, an inhibitor of IL-1 production, blocked the development of AHR, BAL fluid neutrophilia, and decreased levels of IL-1 following O(3) exposure. In summary, acute exposure to O(3) induces AHR, neutrophilic inflammation, epithelial damage, and IL-1. An IL-1Ra effectively prevents the development of altered airway function, inflammation, and structural damage. 相似文献
9.
Okamoto T Yamamoto Y Gotoh M Liu D Kihara M Kameyama K Hayashi E Nakamura K Yamauchi A Huang CL Yokomise H Yamamoto M Nakamura T Shimizu Y Tabata Y 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2003,49(1):63-69
We investigated whether saber sheath-type tracheomalacia could be treated by the slow release of bone morphogenetic protein (BMP)-2 from a gelatin sponge. A 1 cm gap was made in the middle portion of each of 10 consecutive tracheal cartilage rings in the canine cervix (control group, n = 3), then a gelatin sponge containing 12 microg of BMP-2 solution was implanted in the gap (12 microg group, n = 3). In another group (120 microg + P group, n = 3), the implanted gelatin sponge contained 120 microg of BMP-2 solution, and the gap was covered with periosteum. All of the control dogs developed saber sheath-type tracheomalacia, whereas tracheomalacia was not observed in the 12 microg and 120 microg + P groups. In the 12 microg group, fibrous cartilage was observed at the ends of the cartilage stumps. In the 120 microg + P group, newly formed bone and cartilage were observed to form a bridge between the cartilage stumps. The regeneration of cartilage or bone induced by the slow release of BMP-2 from a gelatin sponge might be useful for treatment of tracheomalacia. 相似文献
10.
Differential expression of PD-L1 and PD-L2, ligands for an inhibitory receptor PD-1, in the cells of lymphohematopoietic tissues 总被引:27,自引:0,他引:27
PD-1 is a member of the immunoglobulin superfamily expressed on immune cells, including T and B cells, and is involved in the delivery of inhibitory signal upon engagement of its ligands, PD-L1 and PD-L2. While the expression profile of PD-1 has been well documented, the analysis of PD-L1 and PD-L2 distributions on a protein basis has not been carried out because of the lack of available monoclonal antibodies specific for the molecules. In this study, we established two monoclonal antibodies, 1-111A and 122, specific for murine PD-L1 and PD-L2, respectively, and examined their expression profiles. Based on flow cytometric analyses, the expression of PD-L1 was detected in a variety of lymphohematopoietic cell types, including a minor proportion of T and B cells in the spleen, majority of pre-B cells and myeloid cells in bone marrow and subsets of thymocytes, while the expression of PD-L2 was not observed in the lymphohematopoietic cells at all. Notably, a significant proportion of the most immature lineage-marker-negative and c-Kit-positive bone marrow cells containing stem cells did express PD-L1. Following mitogenic stimulation, essentially all lymphocytes expressed PD-L1. Furthermore, a variety of leukemic lines also expressed PD-L1, while none of them did PD-L2. Thus, present results demonstrate the distinct expression patterns of PD-L1 and PD-L2 with the cells of lymphohematopoietic tissues exclusively expressing the former. 相似文献