全文获取类型
收费全文 | 24546篇 |
免费 | 1309篇 |
国内免费 | 86篇 |
专业分类
耳鼻咽喉 | 153篇 |
儿科学 | 399篇 |
妇产科学 | 403篇 |
基础医学 | 3152篇 |
口腔科学 | 806篇 |
临床医学 | 1784篇 |
内科学 | 5886篇 |
皮肤病学 | 455篇 |
神经病学 | 2207篇 |
特种医学 | 1087篇 |
外科学 | 3603篇 |
综合类 | 94篇 |
一般理论 | 1篇 |
预防医学 | 767篇 |
眼科学 | 454篇 |
药学 | 2014篇 |
中国医学 | 56篇 |
肿瘤学 | 2620篇 |
出版年
2023年 | 102篇 |
2022年 | 231篇 |
2021年 | 426篇 |
2020年 | 245篇 |
2019年 | 350篇 |
2018年 | 405篇 |
2017年 | 303篇 |
2016年 | 390篇 |
2015年 | 437篇 |
2014年 | 574篇 |
2013年 | 687篇 |
2012年 | 1098篇 |
2011年 | 1236篇 |
2010年 | 631篇 |
2009年 | 593篇 |
2008年 | 1089篇 |
2007年 | 1124篇 |
2006年 | 1098篇 |
2005年 | 1076篇 |
2004年 | 1028篇 |
2003年 | 1026篇 |
2002年 | 1023篇 |
2001年 | 934篇 |
2000年 | 950篇 |
1999年 | 940篇 |
1998年 | 319篇 |
1997年 | 248篇 |
1996年 | 232篇 |
1995年 | 197篇 |
1994年 | 175篇 |
1993年 | 163篇 |
1992年 | 661篇 |
1991年 | 572篇 |
1990年 | 603篇 |
1989年 | 584篇 |
1988年 | 495篇 |
1987年 | 458篇 |
1986年 | 453篇 |
1985年 | 404篇 |
1984年 | 280篇 |
1983年 | 236篇 |
1980年 | 93篇 |
1979年 | 241篇 |
1978年 | 145篇 |
1977年 | 129篇 |
1975年 | 100篇 |
1974年 | 96篇 |
1972年 | 105篇 |
1971年 | 103篇 |
1969年 | 101篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
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2.
3.
Kota Sahara Rin Yamada Takashi Fujiwara Koichi Koizumi Shin‐ichiro Horiguchi Tsunekazu Hishima Tatsuro Yamaguchi 《Digestive endoscopy》2015,27(7):768-771
Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood ischemic colitis that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. A 76‐year‐old Japanese man presented to our hospital with a 1‐year history of worsening diarrhea, lower abdominal pain, and weight loss (−6 kg). Laboratory evaluation revealed white blood cell count of 13 200/μL, C‐reactive protein level of 2.0 mg/dL (normal range, 0.0–0.3), and negative results for stool culture (including Clostridium difficile). Colonoscopy showed circumferential and edematous narrowing of the sigmoid colon with deep longitude ulceration. Biopsy was done and examination of the specimen demonstrated no specific ischemia. The patient was treated with bowel rest, antibiotics, and i.v. fluids; however, his symptoms worsened. Finally, sigmoidectomy was carried out. Histological examination demonstrated significant myointimal hyperplasia of mesenteric veins leading to thickening and stenosis of the venous lumen. Therefore, the final diagnosis was IMHMV. Three months following sigmoidectomy, he was asymptomatic. 相似文献
4.
5.
6.
7.
8.
9.
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
10.
S Yamada 《Journal of UOEH》1988,10(2):211-218
Physical activity and nutrition are the most important factors in preserving and/or improving health conditions. The relationship between exercise and nutrition is focused on two different directions: one is the direction toward health promoting, the other is for performance of a long heavy muscular work. For preserving and/or promoting health conditions, energy balance between intake and expenditure must be taken into account. The amount of glycogen stored in muscles is the essential factor to promote a long distance performance of working muscles. Topics that influence the energy balance and glycogen loading used by endurance athletes to improve performance are reviewed. 相似文献