全文获取类型
收费全文 | 19423篇 |
免费 | 882篇 |
国内免费 | 120篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 321篇 |
妇产科学 | 189篇 |
基础医学 | 2244篇 |
口腔科学 | 636篇 |
临床医学 | 1231篇 |
内科学 | 5065篇 |
皮肤病学 | 380篇 |
神经病学 | 1250篇 |
特种医学 | 913篇 |
外科学 | 3454篇 |
综合类 | 66篇 |
一般理论 | 1篇 |
预防医学 | 486篇 |
眼科学 | 285篇 |
药学 | 1316篇 |
中国医学 | 29篇 |
肿瘤学 | 2384篇 |
出版年
2023年 | 128篇 |
2022年 | 221篇 |
2021年 | 454篇 |
2020年 | 240篇 |
2019年 | 313篇 |
2018年 | 402篇 |
2017年 | 331篇 |
2016年 | 421篇 |
2015年 | 380篇 |
2014年 | 540篇 |
2013年 | 669篇 |
2012年 | 1091篇 |
2011年 | 1201篇 |
2010年 | 701篇 |
2009年 | 588篇 |
2008年 | 1008篇 |
2007年 | 1037篇 |
2006年 | 1040篇 |
2005年 | 1002篇 |
2004年 | 956篇 |
2003年 | 900篇 |
2002年 | 904篇 |
2001年 | 492篇 |
2000年 | 548篇 |
1999年 | 521篇 |
1998年 | 238篇 |
1997年 | 188篇 |
1996年 | 132篇 |
1995年 | 145篇 |
1994年 | 135篇 |
1993年 | 108篇 |
1992年 | 264篇 |
1991年 | 273篇 |
1990年 | 262篇 |
1989年 | 269篇 |
1988年 | 229篇 |
1987年 | 240篇 |
1986年 | 247篇 |
1985年 | 228篇 |
1984年 | 162篇 |
1983年 | 114篇 |
1979年 | 124篇 |
1978年 | 91篇 |
1977年 | 92篇 |
1975年 | 58篇 |
1974年 | 62篇 |
1973年 | 66篇 |
1972年 | 59篇 |
1969年 | 66篇 |
1968年 | 55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.
4.
Masaru Sasaki Tsuyoshi Takahashi Soichiro Funaki Koji Tanaka Yasuhiro Miyazaki Naoko Ose Tomoki Makino Yukinori Kurokawa Makoto Yamasaki Kiyokazu Nakajima Yasushi Shintani Masaki Mori Yuichiro Doki 《Asian journal of endoscopic surgery》2021,14(1):116-119
We report a case of a diaphragmatic hernia after a heart transplant operation. A 43-year-old woman, who underwent orthotropic heart transplantation for hypertrophic cadiomyopathy two year earlier, presented with vomiting and epigastric pain. A computed tomography scan showed that the stomach and transverse colon were dislocated in the left thoracic cavity. We diagnosed left diaphragmatic hernia incarceration and performed laparoscopic repair of the diaphragmatic hernia. A 12 × 8 cm diaphragmatic defect was found intraoperatively on the ventrolateral aspect of the left diaphragm, and the stomach with volvulus had herniated into the thorax through the defect. The hernia was considered to be iatrogenic. The diaphragmatic defect was large, and the diaphragm was thinning. We closed the defect by mesh repair. Laparoscopic mesh repair of the diaphragmatic hernia could be performed safely and with minimal invasiveness. 相似文献
5.
6.
7.
Lesley A. Inker Morgan E. Grams Andrew S. Levey Josef Coresh Massimo Cirillo John F. Collins Ron T. Gansevoort Orlando M. Gutierrez Takayuki Hamano Gunnar H. Heine Shizukiyo Ishikawa Sun Ha Jee Florian Kronenberg Martin J. Landray Katsuyuki Miura Girish N. Nadkarni Carmen A. Peralta Dietrich Rothenbacher Mark Woodward 《American journal of kidney diseases》2019,73(2):206-217
8.
9.
Yamaoka Mai Yoshida Mahoko Nakashima Ayumu Doi Shigehiro Naito Takayuki Masaki Takao 《Clinical and experimental nephrology》2022,26(11):1111-1118
Clinical and Experimental Nephrology - The association between N-terminal pro-brain natriuretic peptide (NT-proBNP) and stroke in Japanese hemodialysis (HD) outpatients is unclear. Therefore, in... 相似文献
10.
Takayuki Sakurai Satoshi Watanabe Minoru Kimura Masahiro Sato 《Reproductive Medicine and Biology》2006,5(1):43-50
Background and Aims: The aim of this study was to determine which mouse strains exhibit tolerance to cooling when fertilized oocytes have been stored at 4°C.
Methods: In-vitro -fertilization-derived oocytes of eight mouse strains were incubated at 4°C in 20 mmol/L Hepes-potassium modified simplex optimized medium (KSOM) medium for 0, 24, 48, 60 or 72 h, and then returned to normal culture conditions at 37°C in KSOM medium. The rates of development of cultured oocytes into blastocysts and cell numbers of blastocysts were examined. In some cases, a Comet assay was carried out to evaluate DNA damage. In addition, the effects of β-mercaptoethanol on the development of the 4°C-treated oocytes were assessed.
Results: Of the eight strains tested, BDF1, B6C3F1 and FVB/N strains exhibited relatively higher degrees of tolerance to 4°C treatment and approximately 90%, 83% and 78% of oocytes treated at 4°C for 48 h developed to morphologically normal blastocysts, respectively. Comet assay revealed no clear DNA damage in oocytes treated at 4°C. Treatment with β-mercaptoethanol failed to improve the in vitro survival rate of low-temperature-treated oocytes.
Conclusion: Strain differences were observed in tolerance to cooling treatment when fertilized oocytes were temporarily treated with 4°C, although the reasons for this remain unclear. (Reprod Med Biol 2006; 5 : 43–50) 相似文献
Methods: In-vitro -fertilization-derived oocytes of eight mouse strains were incubated at 4°C in 20 mmol/L Hepes-potassium modified simplex optimized medium (KSOM) medium for 0, 24, 48, 60 or 72 h, and then returned to normal culture conditions at 37°C in KSOM medium. The rates of development of cultured oocytes into blastocysts and cell numbers of blastocysts were examined. In some cases, a Comet assay was carried out to evaluate DNA damage. In addition, the effects of β-mercaptoethanol on the development of the 4°C-treated oocytes were assessed.
Results: Of the eight strains tested, BDF1, B6C3F1 and FVB/N strains exhibited relatively higher degrees of tolerance to 4°C treatment and approximately 90%, 83% and 78% of oocytes treated at 4°C for 48 h developed to morphologically normal blastocysts, respectively. Comet assay revealed no clear DNA damage in oocytes treated at 4°C. Treatment with β-mercaptoethanol failed to improve the in vitro survival rate of low-temperature-treated oocytes.
Conclusion: Strain differences were observed in tolerance to cooling treatment when fertilized oocytes were temporarily treated with 4°C, although the reasons for this remain unclear. (Reprod Med Biol 2006; 5 : 43–50) 相似文献