全文获取类型
收费全文 | 2780篇 |
免费 | 122篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 65篇 |
妇产科学 | 25篇 |
基础医学 | 254篇 |
口腔科学 | 71篇 |
临床医学 | 201篇 |
内科学 | 827篇 |
皮肤病学 | 36篇 |
神经病学 | 130篇 |
特种医学 | 196篇 |
外科学 | 465篇 |
综合类 | 21篇 |
一般理论 | 2篇 |
预防医学 | 62篇 |
眼科学 | 45篇 |
药学 | 201篇 |
中国医学 | 4篇 |
肿瘤学 | 280篇 |
出版年
2023年 | 22篇 |
2022年 | 47篇 |
2021年 | 88篇 |
2020年 | 59篇 |
2019年 | 59篇 |
2018年 | 86篇 |
2017年 | 59篇 |
2016年 | 64篇 |
2015年 | 49篇 |
2014年 | 77篇 |
2013年 | 109篇 |
2012年 | 134篇 |
2011年 | 151篇 |
2010年 | 89篇 |
2009年 | 66篇 |
2008年 | 111篇 |
2007年 | 130篇 |
2006年 | 126篇 |
2005年 | 137篇 |
2004年 | 122篇 |
2003年 | 124篇 |
2002年 | 115篇 |
2001年 | 81篇 |
2000年 | 79篇 |
1999年 | 56篇 |
1998年 | 33篇 |
1997年 | 16篇 |
1996年 | 21篇 |
1995年 | 20篇 |
1994年 | 16篇 |
1993年 | 12篇 |
1992年 | 35篇 |
1991年 | 26篇 |
1990年 | 38篇 |
1989年 | 47篇 |
1988年 | 42篇 |
1987年 | 29篇 |
1986年 | 34篇 |
1985年 | 29篇 |
1984年 | 25篇 |
1983年 | 22篇 |
1979年 | 16篇 |
1978年 | 13篇 |
1977年 | 12篇 |
1974年 | 20篇 |
1973年 | 16篇 |
1972年 | 22篇 |
1971年 | 29篇 |
1970年 | 21篇 |
1969年 | 12篇 |
排序方式: 共有2914条查询结果,搜索用时 15 毫秒
21.
Kentaro Ariyoshi Yota Hiroyama Naoya Fujiwara Tomisato Miura Kosuke Kasai Akifumi Nakata Yohei Fujishima Valerie Swee Ting Goh Mitsuaki A Yoshida 《Journal of radiation research》2021,62(1):73
Alopecia is one of the common symptoms after high-dose radiation exposure. In our experiments, neonatal mice that received 7 Gy X-ray exhibited defects in overall hair growth, except for their cheeks. This phenomenon might suggest that some substances were secreted and prevented hair follicle loss in the infant tissues around their cheeks after radiation damage. In this study, we focused on exosome-like vesicles (ELV) secreted from cheek skin tissues and back skin tissues, as control, and examined their radiation protective effects on mouse fibroblast cell lines. We observed that ELV from irradiated cheek skin showed protective effects from radiation. Our results suggest that ELV from radiation-exposed cheek skin tissue is one of the secreted factors that prevent hair follicle loss after high-dose radiation. 相似文献
22.
A 43-year-old man was found to show cardiac arrest during overnight detention in a police station. The autopsy revealed no abnormality other than a fatty liver on gross examination. Microscopic examination of the heart showed typical disseminated hypoxemic foci of necrosis with hemorrhaging but without infiltration of inflammatory cells, which Büchner, about 60 years ago, proposed as a sign of acute coronary insufficiency without acute coronary occlusion due to massive hemorrhage. However, the disseminated focal hemorrhagic necrosis of microscopic size found in the present study appears to be one of early signs of ischemia in the heart muscle and to occur frequently at silent ischemic heart attacks during daily life. 相似文献
23.
Koroku M Tanda H Kato S Onishi S Nakajima H Nanbu A Nitta T Akagashi K 《Hinyokika kiyo. Acta urologica Japonica》1999,45(10):711-712
A case of transitional cell carcinoma of the bladder in a 18-year-old female is presented. Cystoscopic examination revealed a papillary tumor on the left lateral wall. Histopathology of the excised tumor showed transitional cell carcinoma, G1 > 2, pT1a. Recurrence has not been observed for about 1 year, after intravesical pirarubicin therapy. 相似文献
24.
A case of granulomatous nephritis after intrarenal bacille Calmette-Guérin (BCG) therapy is reported. High fever greater than 38.5 degrees C lasted for 1 month, without response to conservative therapy. Standard nephroureterectomy was subsequently carried out. Histopathologic findings from the surgical specimen were compatible with BCG-induced granulomatous nephritis. The use of a syringe pump for retrograde instillation of BCG was thought to be the major cause of this severe complication. 相似文献
25.
Peripheral-type benzodiazepines have been shown to exert immunological effects. In this study, we examined the effects of the peripheral-type benzodiazepines on murine thymocytes. Murine thymocytes that were incubated with the peripheral-type benzodiazepines underwent apoptosis associated with the collapse of mitochondrial transmembrane potential (delta psi(m)). The drugs stimulated dexamethasone- and etoposide-induced apoptosis with the enhanced collapse of delta psi(m). The central-type benzodiazepines had no effect on either the delta psi(m) or apoptosis. The reduction of delta psi(m) depended on protein synthesis and protein phosphorylation. These results suggest that the immunomodulating effect of benzodiazepines is in part due to the modulation of thymocyte apoptosis associated with the collapse of delta psi(m). 相似文献
26.
Delayed image of iodine-123 iomazenil as a relative map of benzodiazepine receptor binding: The optimal scan time 总被引:2,自引:0,他引:2
Yoshihiro Onishi Yoshiharu Yonekura Fumiko Tanaka Sadahiko Nishizawa Hidehiko Okazawa Koichi Ishizu Toru Fujita Junji Konishi Takao Mukai 《European journal of nuclear medicine and molecular imaging》1996,23(11):1491-1497
Delayed single-photon emission tomograpic (SPET) images after an intravenous bolus injection of iodine-123 iomazenil have been used as a relative map of benzodiazepine receptor binding. We determined the optimal scan time for obtaining such a map and assessed the errors of the map. SPET and blood data from six healthy volunteers and five patients were used. A three-compartment kinetic model was employed in simulation studies and analyses of actual data. The simulation studies suggested that, in the normal brain, the scan time at which a single SPET image best represented the relative receptor binding was 3.0–3.5 h post-injection. This finding was supported by actual data from the volunteers. The simulation studies also suggested that the optimal scan time was not greatly changed by the variability of the input functions, and that the error in the SPET image contrast in the vicinity of the optimal scan time was not increased by changes in the tracer kinetics in the entire brain. The SPET image contrast in the patients at 3.0 h post-injection agreed well with the reference receptor binding estimated by kinetic analysis, with a mean error of 3.6%. These findings support the use of a single SPET image after bolus injection of [123I]iomazenil as a relative map of benzodiazepine receptor binding. For this purpose, a SPET scan time of 3.0-3.5 h post-injection is recommended. 相似文献
27.
28.
A 26-year-old female, the elder of monozygotic twins, presented with slow progressive numbness and pain in her left arm. Magnetic resonance (MR) imaging showed syringomyelia with Chiari malformation. The patient's birth had been difficult with prolonged delivery time, breech delivery, and neonatal asphyxia. MR imaging of the patient's twin sister showed mild tonsillar ectopia, but absence of syringomyelia. This younger sister was born without problems. The patient underwent syringosubarachnoid shunt at the C5-6 level. The syrinx was collapsed promptly, and her symptoms disappeared. This case of syringomyelia with Chiari malformation in one of twins suggests that birth injury is likely to be a cause of the pathogenesis of syringomyelia. 相似文献
29.
Yoshinori Ebato Yoshinori Kato Hiraku Onishi Tsuneji Nagai Yoshiharu Machida 《Drug development research》2003,58(3):253-257
A simple method for the preparation of the inner liposomes for double liposomes (DL) was developed. The encapsulation efficiency of erythrosine in liposomes prepared by this new method is superior to that of the previous method because of the concentration of the drug in the lipid membrane. To evaluate the usefulness of DL prepared by the glass‐filter method modified in this study as an oral dosage form of salmon calcitonin (SCT), a suspension of liposomes containing SCT was administered to rats at a dose of 10 μg SCT/kg. Each type of DL showed better efficacy than its inner liposomes alone. The decrease in plasma calcium level was dependent on the electrical charge and particle size of the inner liposomes. The hypocalcemic efficacy of DL encapsulating SCT‐loading cationic liposomes relative to that after subcutaneous administration of SCT at a dose of 1 μg/kg was 6.47%, which was the largest value obtained. These results indicated that not only the particle size but also the electrical charge of inner liposomes affect intestinal absorption. This study verified that the efficacy was increased because of the decrease in diameter of the inner liposomes and the use of lipid with a positive charge. These findings concluded that DL might be useful as an oral dosage form of SCT. Drug Dev. Res. 58:253–257, 2003. © 2003 Wiley‐Liss, Inc. 相似文献
30.
Miyashita T Ando M Hanafusa Y Onishi Y Kuro M 《The Journal of cardiovascular surgery》2000,41(4):595-599
BACKGROUND: In surgical repair of abdominal aortic aneurysm (AAA), excessive bleeding which causes postoperative complications is sometimes observed. To determine the risk factors of perioperative excessive blood loss, this retrospective study was performed. METHODS: Design. A retrospective study. Setting. An academic medical center. Participants. One hundred and forty patients underwent elective surgical repair of an abdominal aortic aneurysm (AAA) at our institution from 1995 through 1997. Measurements. The present study includes critical review of 140 consecutive charts of patients undergoing elective surgical repair of AAA. Preoperative laboratory data, intraoperative data and amount of blood loss to identify risk factors of perioperative blood loss. Factors which were found to be significantly associated with the amount of perioperative blood loss were preoperative plasma fibrin degradation product (FDP) level (r=0.445), amount of immediate re-infusion of shed blood (r=0.438), and duration of operation (r=0.411). RESULTS: Preoperative fibrinogen level correlated with perioperative blood loss little (r=-0.187). Preoperative platelet count or the other coagulation profile did not affect the amount of perioperative blood loss. The patients whose preoperative FDP were more than 40 microg x ml(-1) significantly increased the risk of excessive blood loss compared with less than 40 microg x ml(-1). CONCLUSIONS: The significant preoperative risk factor of perioperative blood loss was only FDP level in present study. Especially, the patients whose preoperative FDP were more than 40 microg x ml(-1) increased the risk of excessive blood loss. 相似文献