全文获取类型
收费全文 | 11040篇 |
免费 | 501篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 156篇 |
儿科学 | 239篇 |
妇产科学 | 111篇 |
基础医学 | 1500篇 |
口腔科学 | 210篇 |
临床医学 | 710篇 |
内科学 | 3151篇 |
皮肤病学 | 86篇 |
神经病学 | 823篇 |
特种医学 | 432篇 |
外科学 | 1629篇 |
综合类 | 59篇 |
预防医学 | 276篇 |
眼科学 | 265篇 |
药学 | 813篇 |
中国医学 | 26篇 |
肿瘤学 | 1111篇 |
出版年
2023年 | 60篇 |
2022年 | 108篇 |
2021年 | 148篇 |
2020年 | 98篇 |
2019年 | 126篇 |
2018年 | 140篇 |
2017年 | 112篇 |
2016年 | 174篇 |
2015年 | 169篇 |
2014年 | 245篇 |
2013年 | 271篇 |
2012年 | 431篇 |
2011年 | 501篇 |
2010年 | 320篇 |
2009年 | 257篇 |
2008年 | 513篇 |
2007年 | 536篇 |
2006年 | 532篇 |
2005年 | 568篇 |
2004年 | 601篇 |
2003年 | 575篇 |
2002年 | 597篇 |
2001年 | 371篇 |
2000年 | 349篇 |
1999年 | 330篇 |
1998年 | 206篇 |
1997年 | 169篇 |
1996年 | 131篇 |
1995年 | 125篇 |
1994年 | 114篇 |
1993年 | 103篇 |
1992年 | 243篇 |
1991年 | 196篇 |
1990年 | 202篇 |
1989年 | 202篇 |
1988年 | 199篇 |
1987年 | 172篇 |
1986年 | 146篇 |
1985年 | 129篇 |
1984年 | 117篇 |
1983年 | 83篇 |
1982年 | 53篇 |
1981年 | 57篇 |
1979年 | 80篇 |
1978年 | 71篇 |
1976年 | 53篇 |
1972年 | 48篇 |
1971年 | 46篇 |
1970年 | 44篇 |
1968年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
201.
202.
203.
204.
Inorganic arsenic (iAs) and its toxic methylated metabolite, methylarsonous acid (MMAIII), both have carcinogenic potential. Prior study shows iAs-induced malignant transformation in both arsenic methylation-proficient (liver) and methylation-deficient (prostate) cells, but only methylation-proficient cells show oxidative DNA damage (ODD) during this transformation. To further define whether arsenic methylation is necessary for transformation or ODD induction, here we chronically exposed these same liver or prostate cell lines to MMAIII (0.25–1.0 μM) and tested for acquired malignant phenotype. Various metrics of oncogenic transformation were periodically assessed along with ODD during chronic MMAIII exposure. Methylation-deficient and methylation-proficient cells both acquired a cancer phenotype with MMAIII exposure at about 20 weeks, based on increased matrix metalloproteinase secretion, colony formation, and invasion. In contrast, prior work showed iAs-induced transformation took longer in biomethylation-deficient cells (~30 weeks) than in biomethylation-proficient cells (~18 weeks). In the present study, MMAIII caused similar peak ODD levels at similar concentrations and at similar exposure times (18–22 weeks) in both cell types. At the approximate peak of ODD production, both cell types showed similar alterations in arsenic and oxidative stress adaptation factors (i.e., ABCC1, ABCC2, GST-π, SOD-1). Thus, MMAIII causes oncogenic transformation associated with ODD in methylation-deficient cells, indicating that further methylation is not required to induce ODD. Together, these results show that MMAIII and iAs cause an acquired malignant phenotype in methylation-deficient cells, yet iAs does not induce ODD. This indicates iAs likely has both genotoxic and non-genotoxic mechanisms dictated by the target cell’s ability to methylate arsenic. 相似文献
205.
Kengo Takimoto Tomohiro Ueda Fukutaro Shimamoto Yusuke Kojima Yosuke Fujinaga Atufumi Kashiwa Hiroaki Yamauchi Kiichi Matsuyama Takashi Toyonaga Toshikazu Yoshikawa 《Digestive endoscopy》2011,23(2):176-181
Aim: Although the treatment of early gastric cancer with endoscopic submucosal dissection (ESD) has been widely carried out, a standardized method of sedation for ESD has not been established. The purpose of the present study was to evaluate the efficacy and safety of sedation with dexmedetomidine (DEX). Methods: We conducted a randomized study involving 90 patients with gastric tumors who were intended to be treated with ESD. The patients were sedated either with DEX (i.v. infusion of 3.0 µg/kg per h over 5 min followed by continuous infusion at 0.4 µg/kg per h [n = 30]), propofol (PF [n = 30]), or midazolam (MDZ [n = 30]). In all groups, 1 mg MDZ was added i.v. as needed. Results: En bloc resection of the gastric tumor was achieved in 88 (98%) patients. None of the DEX‐sedated patients showed a significant reduction of the oxygen saturation level. The percentage of patients who showed body movement in the DEX group was significantly lower than those in the PF and MDZ groups, and the mean dose of additional MDZ in the DEX group was significantly smaller than that in the MDZ group. The rate of effective sedation was significantly higher in the DEX group compared with the MDZ or PF group. The mean length of ESD in the DEX group was 65 min, which was significantly shorter than in the other two groups. No DEX‐sedated patient developed major surgical complications. Conclusions: Sedation with DEX is effective and safe for patients with gastric tumors who are undergoing ESD. 相似文献
206.
Masahiro Waza Keisuke Maeda Chihiro Katsuragawa Atsuko Sugita Ryotarou Tanaka Asako Ohtsuka Tomo Matsui Keiko Kitagawa Taiki Kishimoto Hiroko Fukui Katsuhisa Kawai Masahiko Yamamoto Michio Isono 《Journal of the American Medical Directors Association》2019,20(4):426-431
Objective
To determine the influence of the Kuchi-kara Taberu (KT) index on rehabilitation outcomes during hospitalized convalescent rehabilitation.Design
A historical controlled study.Setting and Participants
A rehabilitation hospital.Participants
Patients who were admitted to a convalescent rehabilitation ward from June 2014 to May 2017.Measures
Patients’ background characteristics included age, sex, nutritional status, activities of daily living (ADL) assessed using the Functional Impedance Measure (FIM), dysphagia assessed using the Functional Oral Intake Scale (FOIS), and reasons for rehabilitation. The following values before (control group) and after initiation of the KT index intervention period (intervention group) were compared: gain of FIM, length of stay, accumulated rehabilitation time, discharge destination, gain of FOIS, gain of body weight (BW), and nutritional intake (energy and protein).Results
Mean age was 76.4 ± 12.3 years (n = 233). There were no significant differences in the baseline characteristics of the patients at admission between the control and intervention groups, except for reason of rehabilitation. The intervention group demonstrated statistically higher values for the total (P = .004) and motor FIM gain (P = .003), total (P = .018) and motor FIM efficiency (P = .016), and FOIS gain (P < .001), compared with values in the control group. The proportion of patients returning home was statistically more frequent in the intervention group compared with that in the control group (73.4% vs 85.5%, odds ratio 2.135, 95% confidence interval [CI] 1.108-4.113, P = .022). Multivariate analyses indicated that intervention using the KT index was a significant independent factor for increased FIM gain (β coefficient = 0.163, 95% CI 1.379-8.329, P = .006) and returning home (adjusted odds ratio 2.570, 95% CI 1.154-5.724, P = .021).Conclusions/Implications
A rehabilitation program using the KT index may lead to improvement of inpatient outcomes in post-acute care. Further prospective research is warranted to confirm the efficacy of this program. 相似文献207.
208.
209.
210.
Masaki Y Sumiyoshi M Suwa S Ohta H Matsunaga E Tamura H Takaya N Mineda Y Kojima S Nakata Y 《International heart journal》2005,46(2):323-326
Dissection of the sinus of Valsalva is an extremely rare accident during percutaneous coronary intervention (PCI), but it can lead to serious complications such as dissection of the ascending aorta. We experienced a localized dissection of the right coronary cusp without coronary artery involvement that was induced by a guiding catheter during PCI in a patient with acute myocardial infarction. The localized dissection showed pooling of the contrast medium in the acute phase, but it subsided spontaneously after 12 days without any sequelae. Manipulation of the guiding catheter should be performed with great caution not only in the coronary artery but also in the sinus of Valsalva. 相似文献