全文获取类型
收费全文 | 12224篇 |
免费 | 567篇 |
国内免费 | 62篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 189篇 |
妇产科学 | 161篇 |
基础医学 | 1440篇 |
口腔科学 | 492篇 |
临床医学 | 790篇 |
内科学 | 2850篇 |
皮肤病学 | 351篇 |
神经病学 | 858篇 |
特种医学 | 652篇 |
外科学 | 2097篇 |
综合类 | 53篇 |
预防医学 | 441篇 |
眼科学 | 189篇 |
药学 | 931篇 |
中国医学 | 19篇 |
肿瘤学 | 1254篇 |
出版年
2023年 | 71篇 |
2022年 | 89篇 |
2021年 | 223篇 |
2020年 | 122篇 |
2019年 | 152篇 |
2018年 | 238篇 |
2017年 | 184篇 |
2016年 | 240篇 |
2015年 | 196篇 |
2014年 | 318篇 |
2013年 | 377篇 |
2012年 | 577篇 |
2011年 | 637篇 |
2010年 | 355篇 |
2009年 | 310篇 |
2008年 | 526篇 |
2007年 | 566篇 |
2006年 | 553篇 |
2005年 | 548篇 |
2004年 | 518篇 |
2003年 | 465篇 |
2002年 | 471篇 |
2001年 | 430篇 |
2000年 | 486篇 |
1999年 | 452篇 |
1998年 | 154篇 |
1997年 | 125篇 |
1996年 | 103篇 |
1995年 | 93篇 |
1994年 | 100篇 |
1993年 | 72篇 |
1992年 | 233篇 |
1991年 | 234篇 |
1990年 | 242篇 |
1989年 | 246篇 |
1988年 | 207篇 |
1987年 | 232篇 |
1986年 | 228篇 |
1985年 | 214篇 |
1984年 | 147篇 |
1983年 | 106篇 |
1979年 | 113篇 |
1978年 | 85篇 |
1977年 | 80篇 |
1975年 | 54篇 |
1974年 | 62篇 |
1973年 | 66篇 |
1972年 | 57篇 |
1969年 | 62篇 |
1968年 | 52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.
Kanji Takeo Eric Virtudazo Misako Ohkusu Susumu Kawamoto Shoko Ito-Kuwa Sigeji Aoki 《Nippon Ishinkin Gakkai Zasshi》2006,47(4):257-262
In Cryptococcus neoformans the DNA content of cells having tiny buds varied rather widely, depending on growth phases and strains used. Typically, buds of C. neoformans emerged soon after initiation of DNA synthesis in the early exponential phase. However, bud emergence was delayed to G2 during transition to the stationary phase, and in the early stationary phase budding scarcely occurred, although roughly half of the cells completed DNA synthesis. The timing of budding in C. neoformans was shifted to later cell cycle points with progression of the growth phase of the culture. Similarly, a deficit in oxygen was demonstrated to delay the timing of budding, prolong the G2 phase and cause accumulation of cells after DNA synthesis, but before commitment to budding. The C. neoformans homologue of the main cell cycle control gene CDC28/Cdc2 was isolated using degenerate RT-PCR. The full-length coding region was then amplified using primers to target the regions around the start and stop codons. The gene was called CnCdk1 and was found to have high homologies to S. cerevisiae CDC28 and S. pombe cdc2. To determine its function, its ability to rescue S. cerevisiae cdc28-temperature sensitive mutants was tested. S. cerevisiae cdc28-4 and cdc28-1N strains transformed with the pYES2-CnCdk1 construct exhibited growth at the restrictive temperature. Results of the sequence analysis and the ability of CnCdk1 to complement the S. cerevisiae cdc28-ts mutations support its assumed role as the CDC28/cdc2 homologue in C. neoformans. 相似文献
6.
7.
S Makino T Nakojo Y Tsuchida K Hashizume M Nakajima K Atsumi J Tulip 《Journal of pediatric surgery》1986,21(3):240-243
A combination of Photo Radiation Therapy (PRT) using Argon-Dye Laser with hematoporphyrin derivatives (HpD) was used experimentally on a cytogenetically highly malignant neuroblastoma xenograft, which exhibited a homogeneously staining region and caused DNA amplifications in chromosomes. The tumor tissue was treated with 500 joules/cm2 of laser. The dosage of HpD was 50 mg per kg body weight. Necrosis of over 50% of the tumor was observed in half the specimens. Swollen cytoplasmic organelles and ruptured cell and nuclear membranes were observed by electron microscopy after PRT. PRT may be used with other treatment modalities for the removal of residual and metastatic tumors. 相似文献
8.
Immunosuppressive activities of the newly discovered FK506, isolated from Streptomyces tsukubaensis, were examined by using cardiac allotransplantation in the rat, and the mechanisms underlying induction and maintenance of FK506-induced long-term allograft survival were studied. Male rats of WKA (RT1k) and F344 (RT1lvl) strains were used as recipients and donors, respectively, and those of BN (RT1n) strain were used as third-party donors. Treatment with FK506, beginning from the day of allografting for 14, 10, or as few as 4 days, prolonged allograft survival significantly across the major histocompatibility barrier. The minimum doses for prolonging graft survival were 0.1 mg/kg/day by intramuscular treatment and 1.0 mg/kg/day by oral treatment. Treatment with FK506 at a dose of 0.32 mg/kg/day from day 4 until day 10 resulted in all the grafts surviving indefinitely and from days 5 to 10, half the grafts survived indefinitely, suggesting that the agent inhibited ongoing rejection. On the other hand, cyclosporine treatment at a dose of 20 mg/kg/day from day 2 did not prolong graft survival time statistically significantly. Induction of prolonged graft survival was not obtained by pretreatment of the prospective donor or recipient; prolonging effects were observed only when the agent was administered after allografting. Thus, the primary effect of the agent is exerted on responder lymphocytes reacting to the donor antigens in the induction phase of long-term graft acceptance. The mechanisms underlying the maintenance of long-term grafts were analyzed by testing the capacity of lymphocytes or serum of long-term graft-bearing rats to inhibit graft rejection in irradiated grafted hosts. Transfer of 2 x 10(8) lymphocytes from FK506-induced long-term F344 graft-bearing WKA rats resulted in indefinite survival of F344 heart allografts, but it did not prolong survival of third-party BN hearts. Transfer of 2.5 ml serum from long-term graft-bearing rats also prolonged graft survival of F344 hearts, but not BN hearts. These results suggest that donor strain-specific suppressor cells and humoral factor(s) are induced by treatment with FK506 in the presence of allografts, and that they play at least partial roles in the maintenance of long-term allograft acceptance. 相似文献
9.
M Wong K Yasufuku T Nakajima F J F Herth Y Sekine K Shibuya T Iizasa K Hiroshima W K Lam T Fujisawa 《The European respiratory journal》2007,29(6):1182-1186
A diagnosis of sarcoidosis should be substantiated by pathological means in order to thoroughly exclude other diseases. The role of real-time endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the diagnosis of sarcoidosis has not been reported. The purpose of the present study is to evaluate the diagnostic yield of EBUS-TBNA in demonstrating the pathological features of sarcoidosis. In total, 65 patients with suspected sarcoidosis, with enlarged hilar or mediastinal lymph nodes on computed tomography, were included in the study. Patients with a suspected or known malignancy or previously established diagnosis of sarcoidosis were excluded. Convex probe endobronchial ultrasonography integrated with a separate working channel was used for EBUS-TBNA. Surgical methods were performed in those in whom no granulomas were detected by EBUS-TBNA. Patients were followed up clinically. EBUS-TBNA was performed on a total of 77 lymph node stations in 65 patients. A final diagnosis of sarcoidosis was made for 61 (93.8%) of the patients. The remaining four patients were diagnosed as having Wegener's granulomatosis (n=1) or indefinite (n=3). In patients with a final diagnosis of sarcoidosis, EBUS-TBNA demonstrated noncaseating epithelioid cell granulomas in 56 (91.8%) of the patients. No complications were reported. Endobronchial ultrasound-guided transbronchial needle aspiration proved to be a safe procedure with a high yield for the diagnoses of sarcoidosis. 相似文献
10.
Nobuyuki Nakajima Masahisa Masuda Mizuho Imamaki Atsushi Ishida Nobuhiro Tanabe Takayasu Kuriyama 《Annals of thoracic and cardiovascular surgery》2007,13(4):267-271
A 45-year-old female was presented with progressive dyspnea and bilateral leg edema. Pulmonary angiography revealed total occlusion of the right pulmonary artery and significant stenosis of the left pulmonary artery. The inferior lobar artery as well as the segmental arteries were well patent. No pathology was detected elsewhere at the aorta and its branches. The diagnosis of chronic pulmonary arterial occlusion by isolated Takayasu arteritis was made because of the characteristic pattern of angiographic findings and the presence of unusual shunt formation from the coronary artery to the peripheral portion of the pulmonary artery, as well as a characteristic presentation of HLA typing in blood analysis, which strongly suggested the diagnosis of Takayasu arteritis. To restore the pulmonary blood flow, we employed reconstructive surgery by means of bypass procedure, using PTFE graft. Postoperatively there was marked improvement in cardiopulmonary function and the quality of life of the patient. The graft was proved to be patent at long-term follow-up study. An extremely rare case of chronic occlusive pulmonary arteritis, which was surgically treated by means of bypass procedure, is reported herein, and a brief review of previous reports on this subject was attempted. 相似文献