全文获取类型
收费全文 | 166106篇 |
免费 | 13537篇 |
国内免费 | 5127篇 |
专业分类
耳鼻咽喉 | 1174篇 |
儿科学 | 3242篇 |
妇产科学 | 1713篇 |
基础医学 | 24608篇 |
口腔科学 | 3189篇 |
临床医学 | 16800篇 |
内科学 | 23691篇 |
皮肤病学 | 1741篇 |
神经病学 | 8010篇 |
特种医学 | 3899篇 |
外国民族医学 | 22篇 |
外科学 | 13946篇 |
综合类 | 25222篇 |
现状与发展 | 11篇 |
一般理论 | 25篇 |
预防医学 | 12199篇 |
眼科学 | 4579篇 |
药学 | 17489篇 |
15篇 | |
中国医学 | 8091篇 |
肿瘤学 | 15104篇 |
出版年
2024年 | 211篇 |
2023年 | 2329篇 |
2022年 | 3551篇 |
2021年 | 6741篇 |
2020年 | 5745篇 |
2019年 | 6162篇 |
2018年 | 5895篇 |
2017年 | 5407篇 |
2016年 | 5299篇 |
2015年 | 5373篇 |
2014年 | 8804篇 |
2013年 | 9523篇 |
2012年 | 7839篇 |
2011年 | 9052篇 |
2010年 | 7838篇 |
2009年 | 7709篇 |
2008年 | 7817篇 |
2007年 | 8865篇 |
2006年 | 8033篇 |
2005年 | 8030篇 |
2004年 | 7009篇 |
2003年 | 6223篇 |
2002年 | 4598篇 |
2001年 | 4526篇 |
2000年 | 3705篇 |
1999年 | 3444篇 |
1998年 | 2450篇 |
1997年 | 2174篇 |
1996年 | 2293篇 |
1995年 | 2189篇 |
1994年 | 1927篇 |
1993年 | 1756篇 |
1992年 | 1527篇 |
1991年 | 1313篇 |
1990年 | 1111篇 |
1989年 | 1052篇 |
1988年 | 990篇 |
1987年 | 748篇 |
1986年 | 570篇 |
1985年 | 693篇 |
1984年 | 700篇 |
1983年 | 441篇 |
1982年 | 543篇 |
1981年 | 451篇 |
1980年 | 401篇 |
1979年 | 331篇 |
1978年 | 263篇 |
1977年 | 216篇 |
1976年 | 248篇 |
1975年 | 156篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
21.
Hiroshi Kashida 《Digestive endoscopy》2019,31(1):16-23
The aim of the present review was to clarify how we should detect and diagnose sessile serrated polyps (SSP) endoscopically. A systematic search was conducted of MEDLINE from January 2004 through March 2018. Nine findings: (i) proximal location; (ii) size >10 mm; (iii) irregular shape; (iv) indistinctive border; (v) cloud‐like surface; (vi) mucus cap; (vii) rim of debris in white‐light endoscopy; (viii) dilated vessels; and (ix) dilated crypts (pits) in image‐enhanced endoscopy were considered to be candidate discriminators of SSP from hyperplastic polyps. Prospective studies in a general setting are warranted to validate the above‐mentioned endoscopic features of SSP during real‐time colonoscopy and to determine whether these features are useful for the differential diagnosis of SSP. 相似文献
22.
《实用中医内科杂志》2019,(12)
[目的]建立采用HPLC-MS/MS测定连翘中连翘酯苷A、阿魏酸、槲皮素、松脂醇β-D葡萄糖苷、连翘苷的含量的方法,为其开发应用提供方法参考。[方法]色谱柱选用Phenomenex Luna C18柱(150 mm×2. 0 mm,5μm);流动相A:0. 1%甲酸溶液,流动相B:100%乙腈;流速为0. 7 m L/min;进样量为12μL;洗脱梯度设定为:0~5 min,10%~55%B; 5~11 min,55%~100%B。质谱选择负离子扫描,离子源为电喷雾式(ESI)。采用多反应监测的检测模式,喷雾电压:-4. 7 k V,雾化气压0. 5 MPa,雾化温度620℃,氮气压力0. 65 MPa。[结果]本次研究所检测的连翘在可测定浓度的范围内5种成分的峰面积与浓度都表现出较好的线性关系,加样后的回收率在97. 8%~99. 5%之间。[结论]采用HPLC-MS/MS测定连翘中5中成分的含量效果较好,灵敏度高、结果可靠,为连翘的开发应用以及质量控制提供了参考。 相似文献
23.
Shinichi Tsuruta Kenichi Kohashi Yuichi Yamada Minako Fujiwara Yutaka Koga Eikichi Ihara Yoshihiro Ogawa Eiji Oki Masafumi Nakamura Yoshinao Oda 《Cancer science》2020,111(3):1008-1019
ARID1A, one of the subunits in SWI/SNF chromatin remodeling complex, is frequently mutated in gastric cancers with microsatellite instability (MSI). The most frequent MSI in solid‐type poorly differentiated adenocarcinoma (PDA) has been reported, but the SWI/SNF complex status in solid‐type PDA is still largely unknown. We retrospectively analyzed 54 cases of solid‐type PDA for the expressions of mismatch repair (MMR) proteins (MLH1, PMS2, MSH2, and MSH6), SWI/SNF complex subunits (ARID1A, INI1, BRG1, BRM, BAF155, and BAF170) and EBER, and mutations in KRAS and BRAF. We analyzed 40 cases of another histological type of gastric cancer as a control group. The solid‐type PDAs showed coexisting glandular components (76%), MMR deficiency (39%), and complete/partial loss of ARID1A (31%/7%), INI1 (4%/4%), BRG1 (48%/30%), BRM (33%/33%), BAF155 (13%/41%), and BAF170 (6%/2%), EBER positivity (4%), KRAS mutation (2%), and BRAF mutation (2%). Compared to the control group, MMR deficiency and losses of ARID1A, BRG1, BRM, and BAF155 were significantly frequent in solid‐type PDAs. Mismatch repair deficiency was associated with the losses of ARID1A, BRG1, and BAF155 in solid‐type PDAs. In the MMR‐deficient group, solid components showed significantly more frequent losses of ARID1A, BRG1, BRM, and BAF155 compared to glandular components (P = .0268, P = .0181, P = .0224, and P = .0071, respectively). In the MMR‐proficient group, solid components showed significantly more frequent loss of BRG1 compared to glandular components (P = .012). In conclusion, solid‐type PDAs showed frequent losses of MMR proteins and the SWI/SNF complex. We suggest that loss of the SWI/SNF complex could induce a morphological shift from differentiated‐type adenocarcinoma to solid‐type PDA. 相似文献
24.
25.
《Obesity research & clinical practice》2020,14(2):158-163
Although an inverse relationship between body mass index (BMI) and baroreflex sensitivity (BRS) was found, the effect of waist circumference (WC) on BRS is still inconclusive. The contradictory results of previous studies may be related to the heterogeneity and relatively small sample size of the subjects examined. The aim of this population-based study was to investigate whether the influence of increased WC is more detrimental to BRS than BMI. A total of 760 community dwellers were recruited and they were classified into Q1 (n = 189), Q2 (n = 183), Q3 (n = 192) and Q4 (n = 196) groups, based on WC quartiles. Spontaneous BRS was determined by spectral α coefficient method. Valsalva ratio was the longest RR interval after release of Valsalva maneuver divided by the shortest RR interval during maneuver. Cardiac autonomic function was calculated by power spectrum of heart rate in low and high frequency (LF, 0.04–0.15 Hz; HF, 0.15–0.40 Hz), and LF/HF ratio in supine position for five minutes. There were significant differences in spontaneous BRS and Valsalva ratio among different WC groups. In multivariate analysis, obesity was inversely associated with spontaneous BRS and Valsalva ratio. However, these inverse relationships became insignificant after further adjustment for WC quartiles. In contrast, Q4 vs. Q1, Q3 vs. Q1 and Q2 vs. Q1 of WC were inversely related to spontaneous BRS. Q4 vs. Q1 and Q3 vs. Q1 of WC were negatively associated with the Valsalva ratio. In conclusion, increased and even high-normal WC had a stronger adverse effect on BRS than BMI, independent of cardio-metabolic risk factors. 相似文献
26.
Seulbi Lee Hyesook Park Soontae Kim Eun-Kyung Lee Jiyoung Lee Young Sun Hong Eunhee Ha 《International journal of hygiene and environmental health》2019,222(3):533-540
Background
It has been reported that particulate matter (PM) is associated with cardiovascular diseases (CVD) while metabolic syndrome is also an important risk factor for CVD. However, few studies have investigated the epidemiological association between PM and metabolic syndrome.Objective
To investigate the association between one-year exposure to PM with an aerodynamic diameter <2.5?μm (PM2.5) and the risk of metabolic syndrome in Korean adults without CVD.Methods
Exposure to PM2.5 was assessed using a Community Multiscale Air Quality (CMAQ) model. Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III. Andersen and Gill model with time-varying covariates, considering recurrent events, was used to investigate the association between one-year average PM2.5 and the risk of incident metabolic syndrome in 119,998 adults from the national health screening cohort provided by Korea National Health Insurance from 2009 to 2013.Results
Higher risk of metabolic syndrome, waist-based obesity, hypertension, hypertriglyceridemia, low HDL cholesterol, and hyperglycemia were significantly associated with a 10-μg/m3 increase in PM2.5 [adjusted hazard ratio (HR): 1.070, 1.510, 1.499, 1.468, 1.627 and 1.380, respectively]. In addition, the risk of metabolic syndrome associated with PM2.5 exposure was significant in the consistently obese group (obese at baseline and endpoint).Conclusion
Exposure to one-year average PM2.5 is associated with an increased risk of metabolic syndrome and its components in adults without CVD. These associations are particularly prominent in the consistently obese group (obese at baseline and endpoint). Our findings indicate that PM2.5 affects the onset of MS and its components which may lead to increase the risk of CVD. 相似文献27.
28.
29.
目的 初步评估IMRT对无法手术ⅣA期胸腺瘤的疗效及安全性。方法 回顾分析2010-2017年间15例无法手术接受IMRT的ⅣA期胸腺瘤患者,其中男9例、女6例,中位数59岁。PTV、CTV、GTV放疗剂量分别为50、60、70Gy分15~20次,分析近期疗效、总生存率及不良反应。结果 中位随访时间48个月,近期部分缓解率93%(14/15),1、3、5年总生存率分别为100%、75%、75%,仅1例出现3级血液系统反应。4例死亡患者均为肿瘤相关死亡。结论 初步证明ⅣA期胸腺瘤IMRT疗效较好、安全性高,可作为无法手术治疗的胸腺瘤患者安全、有效的治疗手段。 相似文献