全文获取类型
收费全文 | 23440篇 |
免费 | 1548篇 |
国内免费 | 214篇 |
专业分类
耳鼻咽喉 | 383篇 |
儿科学 | 326篇 |
妇产科学 | 306篇 |
基础医学 | 3978篇 |
口腔科学 | 419篇 |
临床医学 | 1914篇 |
内科学 | 4639篇 |
皮肤病学 | 748篇 |
神经病学 | 1986篇 |
特种医学 | 1226篇 |
外科学 | 3254篇 |
综合类 | 85篇 |
一般理论 | 4篇 |
预防医学 | 871篇 |
眼科学 | 603篇 |
药学 | 2147篇 |
中国医学 | 296篇 |
肿瘤学 | 2017篇 |
出版年
2023年 | 209篇 |
2022年 | 512篇 |
2021年 | 840篇 |
2020年 | 430篇 |
2019年 | 604篇 |
2018年 | 702篇 |
2017年 | 530篇 |
2016年 | 804篇 |
2015年 | 1012篇 |
2014年 | 1158篇 |
2013年 | 1377篇 |
2012年 | 2044篇 |
2011年 | 1957篇 |
2010年 | 1126篇 |
2009年 | 920篇 |
2008年 | 1426篇 |
2007年 | 1314篇 |
2006年 | 1225篇 |
2005年 | 1109篇 |
2004年 | 979篇 |
2003年 | 860篇 |
2002年 | 757篇 |
2001年 | 468篇 |
2000年 | 451篇 |
1999年 | 386篇 |
1998年 | 167篇 |
1997年 | 126篇 |
1996年 | 117篇 |
1995年 | 103篇 |
1994年 | 88篇 |
1993年 | 71篇 |
1992年 | 137篇 |
1991年 | 131篇 |
1990年 | 110篇 |
1989年 | 100篇 |
1988年 | 93篇 |
1987年 | 95篇 |
1986年 | 73篇 |
1985年 | 70篇 |
1984年 | 43篇 |
1983年 | 52篇 |
1982年 | 33篇 |
1981年 | 23篇 |
1980年 | 32篇 |
1979年 | 48篇 |
1978年 | 33篇 |
1977年 | 34篇 |
1976年 | 25篇 |
1975年 | 25篇 |
1969年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Maxime Lafond Shin Yoshizawa Shin‐ichiro Umemura 《Journal of ultrasound in medicine》2019,38(3):567-580
Sonodynamic therapy (SDT) consists of the synergetic interaction between ultrasound and a chemical agent. In SDT, the cytotoxicity is triggered by ultrasonic stimuli, notably through cavitation. The unique features of SDT are relevant in the clinical context more than ever: the need for efficacy, accuracy, and safety while being noninvasive and preserving the patient's quality of life. However, despite the promising results of this technique, only a few clinical reports describe the use of SDT. The objective of this article is to provide an extensive overview of the clinical and preclinical research conducted in vivo on SDT, to identify the limitations, and to detail the developed strategies to overcome them. 相似文献
3.
4.
Cheong-Il Shin Sang Joon Park Ji-Hyun Kim Yeonyee Elizabeth Yoon Eun-Ah Park Bon-Kwon Koo Whal Lee 《Korean journal of radiology》2021,22(5):688
ObjectiveTo compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS).Materials and MethodsThe Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods. Bland-Altman plots were used to evaluate the agreement between the measurements.ResultsLumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 mm3; 95% confidence interval [CI], 4.9–24.3 mm3); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, −0.7 mm3; 95% CI, −9.1–7.7 mm3). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 mm2; 95% CI, 0.89–1.25 mm2) but not in the larger lumen area group (mean of difference, −0.07 mm2; 95% CI, −0.22–0.08 mm2). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 mm2; 95% CI, 0.27–0.65 mm2) than in that of IVUS and SATM (1.53 mm2; 95% CI, 1.27–1.79 mm2).ConclusionSATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM. 相似文献
5.
6.
7.
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
8.
Hiroto Kinoshita Hitomi Nishioka Aya Ikeda Kyoko Ikoma Yoichi Sameshima Hidehisa Ohi Mizuki Tatsuno Junka Kouyama Chiaki Kawamoto Tomohiro Mitsui Yuko Tamura Yu Hashimoto Masashi Nishio Tsuyoshi Ogashiwa Yusuke Saigusa Shin Maeda Hideaki Kimura Reiko Kunisaki Kazuhiko Koike 《Journal of gastroenterology and hepatology》2019,34(11):1929-1939
9.
Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case–control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan–Meier analysis with log-rank test (P = 0.008). The AF group''s adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16–1.57; P = 0.009) according to Cox''s proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF. 相似文献
10.
Hae June Lee Yeonghoon Son Minyoung Lee Changjong Moon Sung Ho Kim In Sik Shin Miyoung Yang Sangwoo Bae Joong Sun Kim 《中国神经再生研究》2019,(9)
Sodium butyrate is a histone deacetylase inhibitor that affects various types of brain damages. To investigate the effects of sodium butyrate on hippocampal dysfunction that occurs after whole-brain irradiation in animal models and the effect of sodium butyrate on radiation exposure-induced cognitive impairments,adult C57BL/6 mice were intraperitoneally treated with 0.6 g/kg sodium butyrate before exposure to 10 Gy cranial irradiation. Cognitive impairment in adult C57BL/6 mice was evaluated via an object recognition test 30 days after irradiation. We also detected the expression levels of neurogenic cell markers(doublecortin)and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor. Radiation-exposed mice had decreased cognitive function and hippocampal doublecortin and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression. Sodium butyrate pretreatment reversed these changes. These findings suggest that sodium butyrate can improve radiation-induced cognitive dysfunction through inhibiting the decrease in hippocampal phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression. The study procedures were approved by the Institutional Animal Care and Use Committee of Korea Institute of Radiological Medical Sciences(approval No. KIRAMS16-0002) on December 30, 2016. 相似文献