全文获取类型
收费全文 | 10609篇 |
免费 | 526篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 83篇 |
儿科学 | 132篇 |
妇产科学 | 273篇 |
基础医学 | 1444篇 |
口腔科学 | 217篇 |
临床医学 | 721篇 |
内科学 | 2549篇 |
皮肤病学 | 263篇 |
神经病学 | 767篇 |
特种医学 | 641篇 |
外科学 | 1786篇 |
综合类 | 25篇 |
一般理论 | 1篇 |
预防医学 | 269篇 |
眼科学 | 132篇 |
药学 | 679篇 |
中国医学 | 16篇 |
肿瘤学 | 1196篇 |
出版年
2022年 | 108篇 |
2021年 | 214篇 |
2020年 | 117篇 |
2019年 | 150篇 |
2018年 | 181篇 |
2017年 | 147篇 |
2016年 | 172篇 |
2015年 | 194篇 |
2014年 | 276篇 |
2013年 | 325篇 |
2012年 | 528篇 |
2011年 | 526篇 |
2010年 | 303篇 |
2009年 | 253篇 |
2008年 | 492篇 |
2007年 | 485篇 |
2006年 | 489篇 |
2005年 | 499篇 |
2004年 | 465篇 |
2003年 | 512篇 |
2002年 | 502篇 |
2001年 | 339篇 |
2000年 | 397篇 |
1999年 | 271篇 |
1998年 | 106篇 |
1997年 | 95篇 |
1996年 | 104篇 |
1995年 | 81篇 |
1994年 | 84篇 |
1993年 | 66篇 |
1992年 | 226篇 |
1991年 | 230篇 |
1990年 | 199篇 |
1989年 | 242篇 |
1988年 | 208篇 |
1987年 | 207篇 |
1986年 | 181篇 |
1985年 | 153篇 |
1984年 | 103篇 |
1983年 | 83篇 |
1982年 | 50篇 |
1981年 | 46篇 |
1979年 | 75篇 |
1978年 | 70篇 |
1977年 | 51篇 |
1975年 | 48篇 |
1974年 | 51篇 |
1972年 | 59篇 |
1971年 | 56篇 |
1968年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Shingo Hashimoto Masaki Katsurada Rie Muramatsu Kumiko Asai Kenichiro Tanaka Kensuke Hayashi Yoshiaki Kibe Koichiro Nakajima Yukiko Hattori Hiromitsu Iwata Jun-etsu Mizoe Hiroyuki Ogino Yuta Shibamoto 《Practical radiation oncology》2019,9(2):e149-e155
Purpose
Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed.Methods and Materials
First, respiratory amplitudes of the liver with the device-free compressed shell were analyzed from the data of 146 patients. The effect of this shell fixing method on liver movement was evaluated. Second, as another cohort study with 166 patients, interfractional internal motion of the liver for patients fixed in the shell was calculated using the fiducial marker coordinate data of images for position setting before daily irradiation. Third, in another 12 patients, intrafractional internal motion was calculated from the fiducial marker coordinate data using x-ray images before and after irradiation.Results
The median respiratory movement without the shell, after fixing with the shell, and after instructing on the breathing method with the shell was 14.2 (interquartile range, 10.7-19.8), 11.5 (8.6-17.5), and 10.4 mm (7.3-15.8), respectively. Systematic and random errors of interfractional internal motion were all ≤2 mm in the left-right and anteroposterior directions and 3.7 and 3.0 mm, respectively, in the craniocaudal direction. Systematic and random errors of intrafractional internal motion were all ≤1.3 mm in the left-right and anteroposterior directions and 0.8 and 2.4 mm, respectively, in the craniocaudal direction.Conclusions
The device-free compressed shell fixation method was effective in suppressing the respiratory movement of the liver. Irradiation position matching using the fiducial marker can correct the interfractional internal motion on each day, which would contribute to the reduction of the margin to be given around the target. 相似文献3.
Takahiro Namiki Chika Takano Ryoji Aoki Quang Duy Trinh Ichiro Morioka Satoshi Hayakawa 《Congenital anomalies》2022,62(1):38-41
Congenital rubella syndrome (CRS) results from maternal rubella virus infection in early pregnancy. Abnormal neuroimaging findings have been analyzed in a small number of CRS patients in the past; however, their clinical significance has been poorly addressed. Therefore, we have investigated the neuroimaging findings of 31 patients with CRS from previous studies. The most common finding was parenchymal calcification, which was observed in 18 of 31 patients (58.1%). A multivariable logistic regression model showed that it was associated with psychomotor or mental retardation (p = 0.018), suggesting that parenchymal calcification in CRS could be a prognostic factor. 相似文献
4.
5.
6.
7.
8.
Intraductal papillary mucinous tumor (IPMT) of the pancreas is characterized by slow growth and a relatively favorable prognosis, however, invasive cancer originating in an IPMT is associated with a poor prognosis. Although various parameters in imaging modalities have been advocated to differentiate between benign IPMN and malignant ones, it is not easy to obtain definite diagnosis based on these parameters. Peroral pancreatoscopy (POPS) allows a clear and direct visualization of the pancreatic duct, providing useful information regarding tumor nature in IPMT. The authors have studied the usefulness of POPS in the diagnosis of IPMT. Nevertheless, its usefulness is not necessarily widely accepted and the significance of POPS is still controversial. In this review, the authors intended to address the diagnostic value of POPS and to clarify its role in the diagnosis of IPMT. The authors think treatment of IPMT can be improved by introducing POPS because the determination of surgical procedure as well as the area of resection based on the preoperative diagnosis of the involvement of the main pancreatic duct and branch duct is inevitable. 相似文献
9.
Masahiro Yamauchi Hiroko Kusano Etsuko Saito Takeshi Iwata Masashi Nakakura Yasuki Kato Takaaki Uochi Shiro Akinaga Noboru Aoki 《Journal of controlled release》2006,114(2):268-275
Previously, we demonstrated that wrapping dextran fluorescein anionic/cationic lipid complexes with neutral lipids produced a stable formulation that markedly increased the duration of the compound in plasma after intravenous administration to rats. The improved drug-delivery properties of the wrapped liposomes (WL) relative to other formulations suggested that this technology could offer important advantages for the administration of other polyanionic drugs, including antisense oligodeoxynucleotides (ODN). In the present study, we investigated the value of WL for formulating fluorescence-labeled phosphorothioated ODN (F-ODN). WL encapsulating F-ODN/cationic lipid complexes were prepared efficiently using similar methodology to that used in our earlier study. Studies confirmed that these WL were stable in vitro. Following intravenous administration to mice, free F-ODN and naked F-ODN/cationic lipid complexes were rapidly eliminated whereas administration of the WL resulted in high blood concentrations of drug that were maintained for several hours. Additional studies were conducted in mice that were inoculated with tumor cells (Caki-1 xenograft model, human kidney); in these experiments, intravenous administration of WL delivered 13 times more F-ODN to the tumor site than achieved after injection of free F-ODN. 相似文献
10.
Akira Sawaki Nobumasa Mizuno Kuniyuki Takahashi Tsuneya Nakamura Masahiro Tajika Hiroki Kawai Toshifumi Isaka Hiroshi Imaoka Yasuyuki Okamoto Masatoshi Aoki Hiroyuki Inoue Ahmed AS Salem Yasushi Yatabe Kenji Yamao 《Digestive endoscopy》2006,18(1):40-44
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed. 相似文献