全文获取类型
收费全文 | 5703篇 |
免费 | 501篇 |
国内免费 | 1615篇 |
专业分类
耳鼻咽喉 | 275篇 |
儿科学 | 113篇 |
妇产科学 | 286篇 |
基础医学 | 668篇 |
口腔科学 | 122篇 |
临床医学 | 734篇 |
内科学 | 977篇 |
皮肤病学 | 67篇 |
神经病学 | 428篇 |
特种医学 | 195篇 |
外国民族医学 | 1篇 |
外科学 | 840篇 |
综合类 | 1634篇 |
现状与发展 | 3篇 |
预防医学 | 237篇 |
眼科学 | 87篇 |
药学 | 403篇 |
2篇 | |
中国医学 | 117篇 |
肿瘤学 | 630篇 |
出版年
2024年 | 9篇 |
2023年 | 189篇 |
2022年 | 276篇 |
2021年 | 371篇 |
2020年 | 337篇 |
2019年 | 199篇 |
2018年 | 184篇 |
2017年 | 170篇 |
2016年 | 207篇 |
2015年 | 350篇 |
2014年 | 495篇 |
2013年 | 431篇 |
2012年 | 476篇 |
2011年 | 588篇 |
2010年 | 465篇 |
2009年 | 416篇 |
2008年 | 439篇 |
2007年 | 566篇 |
2006年 | 481篇 |
2005年 | 335篇 |
2004年 | 288篇 |
2003年 | 242篇 |
2002年 | 158篇 |
2001年 | 83篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 18篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 5篇 |
排序方式: 共有7819条查询结果,搜索用时 125 毫秒
1.
2.
Huang Liyan Li Wei Li Yi Song Chaoyuan Wang Pin Wang Hongchun Sun Xiulian 《Neurogenetics》2020,21(1):39-49
neurogenetics - Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic disease leading to stroke and vascular dementia.... 相似文献
3.
目的探讨输尿管支架管结壳患者尿液菌群的分布特点。方法选取2018年10月至2019年3月在山东省立第三医院、山东大学齐鲁医院、济南市中心医院和济南市济钢医院就诊的35例输尿管支架管置入术后患者。纳入标准:年龄18~65岁;输尿管镜碎石术后留置内支架管4周。排除标准:尿液细菌培养阳性;严重肉眼血尿;近期口服抗生素;存在明显残石患者。本研究采用横断面研究方法(临床研究注册号为ChiCTR1800020025),根据有无支架管结壳将患者分为结壳组23例和无结壳组12例。收集拔管当日患者尿液行细菌16s DNA检测。使用UPARSE、UCHIME和RDP calssifier等软件分析两组患者尿液菌群分布特点,明确两组患者尿液中细菌种类总数、细菌丰度,以及丰度占比较大的细菌类别,比较两组患者尿液细菌种类、数量及细菌丰度的差异,明确结壳组患者尿液中丰度占比较大的细菌菌属。结果两组患者的年龄、性别、体质指数、置管侧别、内支架管型号及结石成分差异均无统计学意义(P>0.05)。16s DNA检测结果显示,结壳组丰度占比>1%的菌属数量为11个,丰度占比>0.01%的菌属数量为74个;无结壳组丰度占比>1%的菌属数量为7个,丰度占比>0.01%的菌属数量为11个,两组丰度占比>1%的菌属数量比较差异有统计学意义(t=5.12,P=0.000)。结壳组中菌属丰度占比前3位分别为乳杆菌属(23.1%)、拟杆菌属(18.8%)和未分级拟杆菌属(17.1%),非结壳组中菌属丰度占比前3位分别是为埃希菌-志贺菌属(32.2%)、肠球菌属(24.9%)和假单胞菌属(18.2%)。两组间差异最大的3种细菌是乳杆菌属(P=0.010),拟杆菌属(P=0.004)和未分级拟杆菌属(P=0.004)。结论支架管结壳患者尿液中细菌种类和数量都明显多于非支架管结壳患者。拟杆菌属细菌在支架管结壳患者尿液中的细菌种类丰度较大。 相似文献
4.
5.
6.
BackgroundExtra-regional lymph node metastases strongly determine treatment options in patients with esophageal cancer. Staging modalities such as (FDG-PET) CT scanning frequently show activity in retroperitoneal and lung hilar lymph nodes. This study evaluated the incidence of histologically confirmed metastases, treatment approach and recurrence patterns in patients with (FDG-PET) CT positivity in these regions.MethodsAll patients with (FDG-PET-) CT positive hilar and/or retroperitoneal lymph nodes at primary staging or restaging discussed at a multidisciplinary tumor board meeting for staging of esophageal cancer between January 2012–December 2017 were included. Biopsies and follow-up were evaluated to determine the presence of metastases and progression rates.ResultsFrom 2012 to 2017, 65 of 857 patients (7.6%) were selected with positive retroperitoneal and/or hilar lymph nodes. A total of 47/65 (72.3%) patients had positive retroperitoneal lymph nodes, which contained metastases in 19 (29.2%). When no biopsy was performed and curative treatment was given (n = 14), 9 patients had progression or locoregional and distant recurrence. Positive hilar lymph nodes were identified in 21 (32.3%) patients; 4 were biopsied and none contained metastases. In these patients no recurrence of disease was seen during follow-up.ConclusionsThe majority of biopsied (PET)CT-positive retroperitoneal lymph nodes at staging contained metastases, while biopsied (PET)CT-positive hilar nodes did not. Histological evaluation of (PET)CT -positive retroperitoneal lymph nodes at staging imaging is recommended, while based on this small series, (PET)CT-positive hilar lymph nodes most likely represent reactive lymphadenopathy. 相似文献
7.
《Reproductive biomedicine online》2020,40(5):645-652
Research questionDoes Embryogen®/BlastGen™ culture medium improve live birth rates compared with standard culture medium for women undergoing IVF and intracytoplasmic sperm injection (ICSI) with poor prognosis.DesignRandomized clinical trial. A total of 100 couples undergoing IVF/ICSI were randomly allocated to having their inseminated oocytes incubated in either Embryogen®/BlastGen™ sequential culture media or standard Cleavage/Blastocyst sequential culture media for 5 days (ClinicalTrials.gov Identifier: NCT02305420).ResultsNo statistically significant difference in live birth rate was found between the control group and the Embryogen®/BlastGen™ group (17 [34%] versus 11 [22%], respectively) (OR 0.55; 95% CI 0.22 to 1.32; P = 0.18). After adjustment for maternal age, body mass index and fertilization procedure, the blastulation rate reduced (40.6 ± 26.5 versus 24.6 ± 26.7; RR 0.70, CI 0.52 to 0.95; P < 0.05), and grade of the embryo transferred (OR 0.35, CI 0.16 to 0.77; P < 0.01) when Embryogen®/BlastGen™ medium was used.ConclusionA significant reduction in day-5 embryo outcome parameters was found using Embryogen®/BlastGen™ compared with standard medium, and insufficient evidence of a difference in pregnancy outcomes. Taking into consideration the small samples size, study limitations and strict inclusion criteria of this single-centre study, further research is needed to determine the efficacy of Embryogen®/BlastGen™ medium in couples undergoing IVF/ICSI. 相似文献
9.
10.
《Neuropeptides》2015
The neuropeptide galanin is widely expressed in both the central and peripheral nervous systems. However there is limited understanding of how individual galanin receptor (GalR1, 2, and 3) subtypes mediate the physiological activity of galanin in vivo. To address this issue we utilized NAX-5055, a systemically available, metabolically stable galanin analog. NAX-5055 displays a preference for GalR1 receptors and possesses potent anticonvulsant activity in vivo, suggesting that NAX-5055 engages central galanin receptors. To determine if NAX-5055 also modulates the activity of peripheral galanin receptors, we evaluated the effect of NAX-5055 on blood glucose and insulin levels in mice. Acute and repeated (once daily for four days) systemic administration of NAX-5055 (4 mg/kg) significantly increased blood glucose levels compared to vehicle treated mice. However, a hyperglycemic response was not observed following systemic administration of NAX-805-1, a scrambled analog of NAX-5055, with critical receptor binding residues, Trp2 and Tyr9, reversed. These results suggest that chemical modifications independent of the galanin backbone of NAX-5055 are not responsible for the hyperglycemic response. The effect of NAX-5055 on glucose homeostasis was further evaluated with a glucose tolerance test (GTT). Mice administered either acute or repeated (once daily for four days) injections of NAX-5055 (4 mg/kg) displayed impaired glucose handling and reduced insulin response to an acute glucose (1g/kg) challenge. Here we have shown that systemic administration of a centrally active GalR1-preferring galanin analog produces acute hyperglycemia and an inhibition of insulin release in vivo and that these effects are not attenuated with repeated administration. NAX-5055 thus provides a new pharmacological tool to further the understanding of function of both central and peripheral GalR1 receptors in vivo. 相似文献