全文获取类型
收费全文 | 10499篇 |
免费 | 459篇 |
国内免费 | 77篇 |
学科分类
医药卫生 | 11035篇 |
出版年
2024年 | 10篇 |
2023年 | 90篇 |
2022年 | 172篇 |
2021年 | 277篇 |
2020年 | 144篇 |
2019年 | 188篇 |
2018年 | 256篇 |
2017年 | 181篇 |
2016年 | 265篇 |
2015年 | 221篇 |
2014年 | 331篇 |
2013年 | 383篇 |
2012年 | 689篇 |
2011年 | 706篇 |
2010年 | 432篇 |
2009年 | 348篇 |
2008年 | 682篇 |
2007年 | 720篇 |
2006年 | 698篇 |
2005年 | 732篇 |
2004年 | 675篇 |
2003年 | 627篇 |
2002年 | 656篇 |
2001年 | 101篇 |
2000年 | 84篇 |
1999年 | 114篇 |
1998年 | 173篇 |
1997年 | 140篇 |
1996年 | 110篇 |
1995年 | 108篇 |
1994年 | 87篇 |
1993年 | 89篇 |
1992年 | 56篇 |
1991年 | 67篇 |
1990年 | 43篇 |
1989年 | 45篇 |
1988年 | 52篇 |
1987年 | 46篇 |
1986年 | 23篇 |
1985年 | 18篇 |
1984年 | 26篇 |
1983年 | 21篇 |
1982年 | 20篇 |
1981年 | 21篇 |
1980年 | 21篇 |
1978年 | 13篇 |
1977年 | 12篇 |
1976年 | 8篇 |
1972年 | 6篇 |
1970年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
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
102.
Yoshimi Inagaki Chikara Tashiro Yoshihiro Miwa Ikuto Yoshiya 《Journal of anesthesia》1996,10(2):99-104
To investigate the effects of four volatile anesthetics (halothane, enflurane, isoflurane, and sevoflurane) on postanesthetic
ventilation and levels of consciousness, we enrolled 24 patients undergoing tympanoplasty in this study. Anesthesia was maintained
with 67% nitrous oxide and one of four volatile anesthetics. We measured end-tidal carbon dioxide concentration (CETco2), minute volume (
) and respiratory rate (RR), and determined the volatile anesthetic concentration in whole arterial blood (CBAnesth) and arterial carbon dioxide tension (Paco2) at 20 min and 2h after tracheal extubation. We also observed the level of consciousness (awake, drowsy, and asleep) before
the measurement. Ventilatory variables were similar among the four groups at 20 min, although the ratio of volatile anesthetic
concentration in the alveoli to the minimum alveolar concentration (MAC) (CAAnesth/MAC ratio) calculated from CBAnesth in the halothane group was twice those in the other groups. In the halothane group, Paco2 was significantly higher, and
and RR were significantly lower compared with the isoflurane and sevoflurane groups at 2h. Halothane tended to prolong the
recovery of levels of consciousness. We conclude that isoflurane and sevoflurane provide clinical advantages over halothane
on postanesthetic ventilation and recovery of levels of consciousness. 相似文献
103.
Yuji Yamamori Yoji Saito Megumi Kaneko Yumiko Kirihara Shinichi Sakura Yoshihiro Kosaka 《Journal canadien d'anesthésie》1996,43(11):1175-1179
Purpose
The present study was designed to examine the antinociceptive effects of orally administered ONO-9902, an enkephalinase inhibitor, on both somatic and visceral pain after visceral stress conditions.Methods
Twenty six male rats were examined. Tail-flick (TF) and colorectal distension (CD) tests were used to determine somatic and visceral antinociceptive effects, respectively. Measurements were performed in rats under immediate post-stress conditions (group ST; n = 14) and in rats nor under stress conditions (group NST; n = 12). In the stressed group, the same device, CD, for visceral antinociceptive effects was used for visceral stress and was applied with an intracolonic pressure of 60 mmHg for 20 min after drug administration. The TF latency and CD threshold were measured before and at 30, 40, 50, 60 and 90 min after administration of ONO-9902 300 mg · kg?1 or distilled water.Results
Orally administered ONO-9902 did not produce any changes in the % maximum possible effect (%MPE) in either TF or CD tests in the unstressed group. In the stressed group, %MPE in the CD test increased 18% and 31% at 30 and 40 min, respectively, after oral administration of ONO-9902 compared with the control group (P < 0.05). However, %MPE to TF test did not alter even after the CD-induced stress condition.Conclusion
These results suggest that ONO-9902 may have analgesic effects on visceral pain but not on somatic pain under immediate post-stress conditions. 相似文献104.
105.
106.
HPLC法测定丹参类注射液中4种水溶性成分含量 总被引:24,自引:0,他引:24
目的采用HPLC法同时测定香丹注射液 (复方丹参注射液 )及丹参注射液中 4种水溶性成分丹酚酸B、迷迭香酸、丹参素和原儿茶醛含量。方法采用HypersilC18(2 5 0mm× 4 6mm ,5 μm)色谱柱 ;以甲醇 水 二甲基甲酰胺 冰醋酸为流动相梯度洗脱 ;流速为 1 0mL/min ;柱温为 35℃ ;检测波长 2 80nm。结果丹参素、原儿茶醛、迷迭香酸和丹酚酸B线性范围分别在 0 0 194~0 194 0 g·L-1、0 0 0 4 0 4~ 0 0 4 0 4 g·L-1、0 0 0 80 8~ 0 0 80 8g·L-1和 0 0 2 6 0~ 0 2 6 0 0 g·L-1内 ,线性关系良好 (r≥ 0 9998) ;加样回收率分别为 10 4 % ,98 3% ,10 1% ,10 3% ,RSD <2 0 %。结论本研究为丹参类注射液的质量综合评价和控制提供了简单、准确、可行的分析方法。 相似文献
107.
108.
Yumiko Kasugai Hiroyuki Tagawa Yoshihiro Kameoka Yasuo Morishima Shigeo Nakamura Masao Seto 《Clinical cancer research》2005,11(23):8265-8272
PURPOSE: Increases in gene dosage through DNA amplification represents a common feature of many tumors and can result in the up-regulation of tumor-promoting genes. Our recent genome-wide, array-based comparative genomic hybridization analysis of 66 cases of diffuse large B-cell lymphoma found that genomic gain of 6p21 was observed in as many as 17 cases, including 14 cases with low-level copy number gain and three cases with high-level copy number gains (amplifications). EXPERIMENTAL DESIGN AND RESULTS: To identify the target gene(s) for 6p21 amplification, we constructed a detailed amplicon map at the region of genomic amplification with the aid of high-resolution contig array-based comparative genomic hybridization glass slides, consisting of contiguously ordered bacterial artificial chromosome/P1-derived artificial chromosome clones covering 3 Mb throughout the 6p21 amplification region. Alignment of the amplifications identified a minimally overlapping 800 kb segment containing 15 genes. Quantitative expression analysis of the genes from both patient samples and the SUDHL9 cell line revealed that CCND3 and BYSL (1.9 kb telomeric to the CCND3 gene locus) are the targets of 6p21 genomic gain/amplification. CONCLUSIONS: Although it is known that t(6;14)(p21;q32) induces aberrant overexpression of CCND3 in B-cell malignancies, we were able to show that CCND3, which encodes the cyclin D family member protein that controls the G1-S phase of cell cycle regulation, can also be a target of genomic gain/amplification. Overexpression of CCND3 through genomic amplification is likely to lead to aberrant cell cycle control, although the precise biological role of BYSL with respect to tumorigenesis remains to be determined. 相似文献
109.
Daisuke Suzuki Yoshihiro Suzuki Daisuke Sato Kenji Kikuchi Naoki Kanauchi Akiko Nishida Yasuyuki Ohta 《Internal medicine (Tokyo, Japan)》2022,61(9):1443
Anti-voltage-gated potassium channel complex antibodies-mediated disorder includes Isaacs'' syndrome, which is characterized by neuromyotonia, and Morvan syndrome, which is characterized by neuromyotonia, encephalopathy and autonomic dysfunction. We herein report a patient with Morvan syndrome that converted from Isaacs'' syndrome after thymectomy. The patient first presented with myospasm in all extremities and positivity for both anti-leucine-rich glioma inactivated 1 (LGI1) and anti-contactin-associated protein like 2 (CASPR2) antibodies and subsequently developed encephalopathy after thymectomy, which was successfully improved by immunotherapy. This is the first case of Morvan syndrome wherein thymectomy worsened Isaacs'' syndrome, suggesting that immunotherapy should be considered for Isaacs'' syndrome accompanied by positivity for both anti-LGI1 and anti-CASPR2 antibodies to prevent worsening to Morvan syndrome. 相似文献
110.
The rhizomes of Helleborus orientalis have been analyzed for the bufadienolide glycoside and spirostanol saponin constituents, resulting in the isolation of a new bufadienolide rhamnoside (1), along with two known bufadienolide glycosides (2 and 3) and five new spirostanol saponins (4-8). The structures of the new compounds were determined on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activities against cultured tumor and normal cells. 相似文献