全文获取类型
收费全文 | 13997篇 |
免费 | 1704篇 |
国内免费 | 973篇 |
专业分类
耳鼻咽喉 | 91篇 |
儿科学 | 243篇 |
妇产科学 | 88篇 |
基础医学 | 1245篇 |
口腔科学 | 318篇 |
临床医学 | 1876篇 |
内科学 | 1649篇 |
皮肤病学 | 123篇 |
神经病学 | 659篇 |
特种医学 | 480篇 |
外国民族医学 | 1篇 |
外科学 | 1190篇 |
综合类 | 3252篇 |
现状与发展 | 2篇 |
预防医学 | 1287篇 |
眼科学 | 353篇 |
药学 | 1782篇 |
24篇 | |
中国医学 | 1183篇 |
肿瘤学 | 828篇 |
出版年
2024年 | 117篇 |
2023年 | 310篇 |
2022年 | 712篇 |
2021年 | 862篇 |
2020年 | 693篇 |
2019年 | 501篇 |
2018年 | 499篇 |
2017年 | 495篇 |
2016年 | 417篇 |
2015年 | 672篇 |
2014年 | 805篇 |
2013年 | 895篇 |
2012年 | 1284篇 |
2011年 | 1248篇 |
2010年 | 1008篇 |
2009年 | 817篇 |
2008年 | 967篇 |
2007年 | 829篇 |
2006年 | 727篇 |
2005年 | 658篇 |
2004年 | 401篇 |
2003年 | 395篇 |
2002年 | 318篇 |
2001年 | 266篇 |
2000年 | 226篇 |
1999年 | 131篇 |
1998年 | 71篇 |
1997年 | 77篇 |
1996年 | 47篇 |
1995年 | 31篇 |
1994年 | 38篇 |
1993年 | 24篇 |
1992年 | 21篇 |
1991年 | 18篇 |
1990年 | 26篇 |
1989年 | 17篇 |
1988年 | 17篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1980年 | 1篇 |
1972年 | 1篇 |
1965年 | 2篇 |
1964年 | 2篇 |
1963年 | 1篇 |
1957年 | 2篇 |
1955年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Nishikawa Y Iwata A Katsumata A Xuan X Nagasawa H Igarashi I Fujisaki K Otsuka H Mikami T 《Virus research》2001,75(2):113-121
A recombinant vaccinia virus-expressing canine interferon (IFN)-gamma (vv/cIFN-gamma) was constructed. In rabbit kidney (RK13) and canine A72 cells infected with vv/cIFN-gamma, IFN activity was detected in the culture supernatants of both cell types. Canine IFN-gamma was also detected in both cell extracts by Western blot. The activity of the recombinant canine IFN-gamma in RK13 cells was higher than that in A72 cells. The vv/cIFN-gamma could not grow in A72 cells at a low multiplicity of infection, probably due to the antiviral activity of the canine IFN-gamma produced. Although exogenous IFN-gamma did not inhibit the growth of vaccinia virus, addition of anti-canine IFN-gamma serum recovered the growth of the vv/cIFN-gamma on A72 cells in a dose-dependent manner. These results suggest that the growth of vv/cIFN-gamma was inhibited by IFN-gamma produced in a paracrine and autocrine manner. In addition, the recombinant canine IFN-gamma inhibited the multiplication of canine herpesvirus, pseudorabies virus and canine adenovirus type 1 in Madin-Darby canine kidney cells. The antiviral effect of canine IFN-gamma was more effective than that of canine IFN-beta. From the present studies, we concluded the recombinant virus may be a useful suicide viral vector. 相似文献
12.
13.
Cloning of a truncated Babesia equi gene encoding an 82-kilodalton protein and its potential use in an enzyme-linked immunosorbent assay 下载免费PDF全文
Hirata H Ikadai H Yokoyama N Xuan X Fujisaki K Suzuki N Mikami T Igarashi I 《Journal of clinical microbiology》2002,40(4):1470-1474
To isolate Babesia equi genes encoding immunodominant proteins, a cDNA expression library prepared from B. equi mRNA was immunoscreened with B. equi-infected horse serum. Eighteen positive cDNA clones were obtained, and the clone that showed the strongest immunoreactivity, designated Be82, was further characterized. The Be82 gene consisted of 1,953 bp and contained a partial open reading frame lacking the 5'-terminal sequence. As shown by Western blot analyses, immune sera from mice intraperitoneally injected with the Be82 gene product recognized the 82- and 52-kDa proteins of B. equi but not those of Babesia caballi. The glutathione S-transferase fusion protein expressed in Escherichia coli that was purified and used as the antigen in the enzyme-linked immunosorbent assay reacted specifically with B. equi-infected horse sera. These results suggest that the Be82 gene product is a potential diagnostic antigen candidate in the detection of B. equi infection in horses that will be useful both in the performance of epidemiological studies and in the granting of quarantine passes. 相似文献
14.
Xuan Xuenan Nishikawa Yoshifumi Takashima Yasuhiro Tuchiya Kotaro Ueda Susumu Yokoyama Naoaki Maeda Ken Mikami Takeshi Otsuka Haruki 《Virus genes》1998,17(1):25-32
An improved method for constructing canine herpesvirus (CHV) recombinants expressing foreign genes by using the lacZ-TK gene
cassette as a double selectional marker was developed. A recombinant CHV carrying the lacZ-TK gene at a targeted gene locus
was constructed and used as a parental virus for generating new recombinants. The parental virus formed blue plaques and was
sensitive to TK-specific drugs, while newly generated recombinants, in which the lacZ-TK gene was replaced with the desired
foreign gene, become both resistant to the TK-specific drugs and formed white plaques. Recombinants were isolated by using
the combination of drug selection and color selection. This improved method allows construction of recombinant CHV with great
ease, because the drug selection can enrich the frequency of recombinant CHV from 0.01–0.1% to 10–80%. This method was employed
to construct a recombinant CHV that expressed rabies virus (RV) glycoprotein (G protein).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
16.
Xu Li Siming Li Zhihong Chi Chuanliang Cui Lu Si Xieqiao Yan Lili Mao Bin Lian Bixia Tang Xuan Wang Xue Bai Li Zhou Yan Kong Jie Dai Jun Guo Xinan Sheng 《Urologic oncology》2021,39(1):75.e1-75.e8
PurposeTo investigate the clinical characteristics, chemosensitivity, and outcome of metastatic upper tract urothelial carcinoma (UTUC).Patients and MethodsRecords of patients with metastatic UTUC since January 2005 were retrieved from a database that included clinical and survival data. Statistical analyses including survival and multivariate analyses of factors were respectively performed by the Kaplan-Meier method and Cox proportional hazard model.ResultsA total of 250 consecutive UTUC cases were evaluated. There were 56 patients (22.4%) with initially diagnosed stage IV disease. The most common metastatic sites were lung (39.6%), distant lymph nodes (39.2%), bone (19.6%), liver (18.0%), and adrenal gland (7.2%), respectively, and the local recurrence rate was 10.4%. Two hundred thirteen patients received first-line chemotherapy. The overall response rate was only 28.7% and the median progression-free survival time was only 5.0 months. The overall survival time of the cohort was 18.0 months. Multivariate analyses showed that initially diagnosed stage IV disease, number of metastatic organs ≥3, no response to chemotherapy and cycles of chemotherapy ≤2 were adverse prognosticators for overall survival.ConclusionUTUC presented to be more prone to metastasize than locally recur and thought to have low chemosensitivity. Stage IV disease at initial diagnosis, number of metastatic organs, response and cycles of chemotherapy were independent prognosticators for metastatic UTUC. 相似文献
17.
目的 本研究旨在比较颅内大血管伴/不伴同侧颈内动脉闭塞的大动脉粥样硬化型脑卒中患者基线特征以及行血管内治疗后结局的差异。方法 对DIRECT-MT亚组进行回顾性分析,以比较前循环大动脉粥样硬化(large-artery atherosclerosis,LAA)型卒中串联闭塞和颅内闭塞接受血管内治疗(endovascular treatment,EVT)的患者的基线特征和预后,分析不同机制学特征(动脉粥样硬化或动脉-动脉栓塞)对临床结局的影响。结果 LAA型卒中患者共108例,其中串联闭塞63例,颅内闭塞45例。颅内闭塞组患者高血压史率高于串联闭塞组(77.8% vs. 52.4%, P=0.007)。颅内闭塞组闭塞部位最常见于大脑中动脉M1段(88.6%),而串联闭塞组颅内闭塞主要位于颈内动脉颅内段(49.2%)和大脑中动脉M1段(49.2%)(P<0.001)。两组患者在年龄、性别、术前抗栓、他汀类药物的使用,卒中、房颤、吸烟史,基线mRS、NIHSS评分,是否静脉溶栓,侧枝循环,以及救治流程时间差异均无统计学意义(P均>0.05)。90天mRS 0-2分的患者比例两组差异无统计学意义(53.3% vs. 41.9%, P=0.243)。颅内闭塞组术后成功再灌注率高于串联闭塞组(93.3% vs. 77.4%, P=0.026),但术后24-72小时血管再通的比例前组低于后组(57.1% vs. 77.2%, P=0.034)。最终梗死体积,颅内闭塞组小于串联闭塞组(20.1 vs. 34.5, P=0.025)。术后NIHSS评分,90天EQ-5D-5L评分和BI指数等其他次要结局,两组间差异无统计学意义(P均>0.05)。两组在90天内的死亡率,发生的无症状性和症状性颅内出血率,5-7天时在另外的血管区域新发脑梗死,以及新流域栓塞的患者百分比相似,差异无统计学意义(P均>0.05)。结论 动脉粥样硬化导致的串联闭塞相较于孤立颅内闭塞,末次造影成功再灌注率较低,梗死体积更大,但术后24-72小时再通率更高,且神经功能良好预后率以及不良事件发生率均与颅内闭塞相仿。 相似文献
18.
目的 研究Homer1b/c蛋白在谷氨酸诱发的细胞自噬中的作用及机制。方法 选用小鼠海马细胞系HT22细胞,通过500 ?mol/L谷氨酸处理建立细胞损伤模型。用siRNA慢病毒转染方式下调Homer1b/c表达和10 ?mol/LBAPTA-AM(1,2-双(2-氨基苯氧基)乙烷-N,N,N`,N`-四乙酸四乙酸甲酯,钙离子螯合剂)、10 mmol/L4-PBA(4-苯基丁酸,内质网应激抑制剂)分别抑制细胞内钙离子释放和内质网应激后,使用蛋白质印迹法检测Homer1b/c,自噬蛋白Beclin-1、微管相关蛋白轻链3(LC3),以及内质网应激标志蛋白CHOP(人内质网应激相关蛋白)、GRP-78(葡萄糖调节蛋白78)的表达水平。每组实验均进行3次,采用独立样本t检验和单因素方差分析进行统计学分析。结果 谷氨酸处理HT22细胞12 h后,Beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值均升高(P<0.05),下调Homer1b/c表达可降低Beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值的升高程度(P<0.05)。抑制细胞内钙离子释放和抑制内质网应激均能降低Beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值的升高程度(P<0.05)。然而在下调Homer1b/c表达后,抑制细胞内钙离子释放和抑制内质网应激未能进一步降低Beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值的升高程度(P<0.05)。结论 Homer1b/c能够调节谷氨酸诱导的自噬,其调节作用可能与内质网功能有关。 相似文献
19.
20.