全文获取类型
收费全文 | 17073篇 |
免费 | 1452篇 |
国内免费 | 962篇 |
专业分类
耳鼻咽喉 | 153篇 |
儿科学 | 214篇 |
妇产科学 | 331篇 |
基础医学 | 2112篇 |
口腔科学 | 351篇 |
临床医学 | 2282篇 |
内科学 | 2711篇 |
皮肤病学 | 245篇 |
神经病学 | 878篇 |
特种医学 | 516篇 |
外国民族医学 | 7篇 |
外科学 | 1835篇 |
综合类 | 2449篇 |
现状与发展 | 1篇 |
一般理论 | 11篇 |
预防医学 | 957篇 |
眼科学 | 423篇 |
药学 | 1748篇 |
8篇 | |
中国医学 | 698篇 |
肿瘤学 | 1557篇 |
出版年
2024年 | 62篇 |
2023年 | 274篇 |
2022年 | 628篇 |
2021年 | 741篇 |
2020年 | 553篇 |
2019年 | 544篇 |
2018年 | 591篇 |
2017年 | 488篇 |
2016年 | 446篇 |
2015年 | 730篇 |
2014年 | 907篇 |
2013年 | 923篇 |
2012年 | 1306篇 |
2011年 | 1425篇 |
2010年 | 906篇 |
2009年 | 717篇 |
2008年 | 889篇 |
2007年 | 935篇 |
2006年 | 865篇 |
2005年 | 838篇 |
2004年 | 582篇 |
2003年 | 554篇 |
2002年 | 403篇 |
2001年 | 373篇 |
2000年 | 378篇 |
1999年 | 442篇 |
1998年 | 278篇 |
1997年 | 286篇 |
1996年 | 197篇 |
1995年 | 171篇 |
1994年 | 141篇 |
1993年 | 103篇 |
1992年 | 112篇 |
1991年 | 87篇 |
1990年 | 75篇 |
1989年 | 67篇 |
1988年 | 93篇 |
1987年 | 83篇 |
1986年 | 51篇 |
1985年 | 46篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 18篇 |
1981年 | 18篇 |
1980年 | 12篇 |
1979年 | 29篇 |
1978年 | 9篇 |
1976年 | 9篇 |
1975年 | 10篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Objective: To construct an eukaryotic expression vector containing Smac gene and study the expression efficiency and specificity of prostate specific antigen(PSA) enhancer/promoter in a possible targeted gene therapy scheme for prostate cancer. Methods: PSA enhancer (PSAE) and promoter (PSAP) sequences were amplified using PCR method. CMV and T7 promoters were deleted from pcDNA3.1-Smac and replaced by the two specific fragments to generate pPSAE-PSAP-Smac. After transfection into different cell lines, the status of cells was observed. And then, we determined the relative concentration of Smac mRNA in RT-PCR. Results: The recombinant plasmid of pPSAE-PSAP-Smac was successfully constructed. And only the prostate cancer cell line PC-3 was suppressed after transfection with pPSAE-PSAP-Smac. However, other nonprostate lines were not. Moreover,the concentration of Smac mRNA regulated by PSA promoter and enhancer was higher in comparison to the CMV promoter-driven control vectors. Conclusion: An expression vector containing the Smac gene (based on elements of the PSA gene regulatory sequences) has been developed and shown to function in prostate cancer cell lines which provides a solid platform for launching clinical studies. 相似文献
82.
免疫结合胶体金层析法和ELISA检测HBsAg用于口岸卫生检疫的风险评估 总被引:1,自引:0,他引:1
目的评估免疫结合胶体金层析法(dot immunochromatography gold assay,DICGA)和ELISA检测HBsAg在口岸卫生检疫中的风险.方法用ELISA对血清标本进行HBsAg检测,对阳性标本用DICGA复检,对复检阴性标本再用ELISA检测.比较两种方法的一致性.分析DICGA阴性,而ELISA阳性的标本数在各个吸光度区间的构成比.结果对10 566份出入境人员血清标本用ELISA进行两对半检测,对1 189份HBsAg阳性血清用DICGA进行复核检验,对其中328份DICGA阴性标本再次用ELISA检验,检出39份阳性,289份阴性.DICGA的敏感性为95.67%,准确性为96.72%,特异性为100%,两种方法的一致性(Kappa值)达91.48%.DICGA阴性但是ELISA阳性的标本数在各个吸光度区间的构成比分别是(1.5,1.0)17%,(1.0,0.5)50%,(0.5,0.105)100%.DICGA在(1.5,0.105)区间有一半以上HBsAg不能检出(56.52%),在(1.0,0.105)有77.78%的假阴性,对(0.5,0.105)则基本不能检出.对ELISA两种试剂的假阳性率分别为:34.66%(269/776)和4.84%(20/413).结论在口岸卫生检疫中,不宜单独用DICGA检测HBsAg.对ELISA需要选择质量高的试剂,每个实验室最好在使用前亲自傲试剂评估. 相似文献
83.
84.
Wang Liuyue Gong Juxin Huang Chunlan Li Junli Chen Liucui Zhang Xialu Liao Qiujiao Liu Fangyin 《Medicine》2022,101(30)
This study aimed to investigate the current status and influencing factors of kinesiophobia in patients after insertion of peripherally inserted central catheter (PICC).A total of 240 patients with PICC were included. Their postinsertion status and influencing factors were investigated using the general information questionnaire, Tampa Scale of Kinesiophobia (TSK), Medical Coping Modes Questionnaire, Numerical Rating Scale, and Self-rating Anxiety Scale.The mean TSK score was 36.49 ± 4.19 points, and 89 patients (37.08%) had kinesiophobia. Multiple linear regression analysis showed that factors such as education level, age, monthly income level, catheterization history, face, pain level, anxiety, and number of needle insertions influenced postoperative kinesiophobia in patients with PICC (P < .05). The total variation in the TSK score was 71.8%.The incidence of kinesiophobia was relatively high after PICC insertion. The medical staff needs to undertake targeted intervention measures to help minimize kinesiophobia after PICC insertion, allowing patients to perform scientifically correct functional exercises and attain physical recovery. 相似文献
85.
Ruijie Yan Enying Gong Xinxuan Li Lutong Zheng Wei Liao Kaiyuan Min Fenghua Su Lianjun Wang Jing Wang Denghui Hu Yuxiang Tang Juan Zhang 《Nutrients》2022,14(14)
The excessive consumption of sugar-sweetened beverages (SSBs) has been proven to be critical for obesity among preschoolers. This study aimed to describe the SSB consumption rates among preschoolers in the Dongcheng District of Beijing, China, and to explore the association between obesogenic environmental determinants and consumption. We applied a stratified cluster sampling method and recruited 3057 primary caregivers of preschoolers in June 2019 to participate in the survey. The caregivers reported their children’s consumption rates of six categories of SSBs and their exposure rates to SSB-related obesogenic environments. The associations between them were tested using multivariate logistic regression models. The mean (SD) age of the children was 5.6 (0.6) years and nearly half (48.3%) were girls. About 84.5% of the children had consumed SSBs over the past three months, and sugar-sweetened milk beverages had the highest consumption rate. Higher exposure to advertisements for the corresponding SSB categories in children, higher frequency rates of consuming SSBs and of taking children to fast-food restaurants in caregivers, and lower frequency rates of reading the Nutrition Facts Panels by caregivers were associated with higher SSB consumption rates among children (p < 0.05 in all of the SSB categories investigated, except for the Nutrition Facts Panel reading behaviors for the sports and energy beverages). SSB consumption among preschoolers is of concern, and comprehensive policy actions and education are urgently needed. 相似文献
86.
Xin-li Liang Miao-miao Ji Zheng-gen Liao Guo-wei Zhao Xi-lan Tang Wei Dong 《The Korean journal of physiology & pharmacology》2022,26(3):145
Multidrug resistance of tumors has been a severe obstacle to the success of cancer chemotherapy. The study wants to investigate the reversal effects of imperatorin (IMP) on doxorubicin (DOX) resistance in K562/DOX leukemia cells, A2780/Taxol cells and in NOD/SCID mice, to explore the possible molecular mechanisms. K562/DOX and A2780/Taxol cells were treated with various concentrations of DOX and Taol with or without different concentrations of IMP, respectively. K562/DOX xenograft model was used to assess anti-tumor effect of IMP combined with DOX. MTT assay, Rhodamine 123 efflux assay, RT-PCR, and Western blot analysis were determined in vivo and in vitro. Results showed that IMP significantly enhanced the cytotoxicity of DOX and Taxol toward corresponding resistance cells. In vivo results illustrated both the tumor volume and tumor weight were significantly decreased after 2-week treatment with IMP combined with DOX compared to the DOX alone group. Western blotting and RT-PCR analyses indicated that IMP downregulated the expression of P-gp in K562/DOX xenograft tumors in NOD/SCID mice. We also evaluated glycolysis and glutamine metabolism in K562/DOX cells by measuring glucose consumption and lactate production. The results revealed that IMP could significantly reduce the glucose consumption and lactate production of K562/DOX cells. Furthermore, IMP could also remarkably repress the glutamine consumption, α-KG and ATP production of K562/DOX cells. Thus, IMP may sensitize K562/DOX cells to DOX and enhance the anti-tumor effect of DOX in K562/DOX xenograft tumors in NOD/SCID mice. IMP may be an adjuvant therapy to mitigate the multidrug resistance in leukemia chemotherapy. 相似文献
87.
晚发型脊柱骨骺发育不良伴进行性骨关节病患者的成骨细胞增殖分化及基因表达谱改变 总被引:3,自引:0,他引:3
Zhou HD Huang QX Xie H Liu M Guo LJ Yuan LQ Sui GL Zhai MX Peng YQ Gu W Ni JD Zhang XS Liao EY 《中华医学杂志》2005,85(19):1310-1314
目的探讨晚发型脊柱骨骺发育不良伴进行性骨关节病(SEDT PA)患者WISP3基因突变所造成的软骨及周围骨组织病变和可能的发病机制。方法从SEDT PA患者及正常同龄个体的股骨头松质骨分离成骨细胞进行体外培养,对培养的成骨细胞进行细胞增殖、骨特异性碱性磷酸酶(BAP)、骨钙素、护骨素测定,利用cDNA表达芯片进行基因表达谱分析,并用免疫组织化学方法对基因芯片进行验证。比较SEDT PA患者及正常对照的成骨细胞在细胞增殖、分化及基因表达谱等方面的改变。同时采用Northern杂交检测成骨细胞的WISP3表达情况。结果与正常人成骨细胞相比,SEDT PA患者成骨细胞的增殖能力较强(0.86±0.04vs0.71±0.10),氚胸腺嘧啶(3H TDR)的掺入量明显较高(1363cpm±350cpmvs867cpm±128cpm)。SEDT PA患者的成骨细胞骨钙素的表达水平明显低于正常同龄人(3.62ng/μg蛋白±0.3ng/μg蛋白vs0.85ng/μg蛋白±0.06ng/μg蛋白),护骨素的表达明显低于正常同龄人(9.43pg/μg蛋白±0.41pg/μg蛋白vs1.98pg/μg蛋白±0.03pg/μg蛋白),而BAP的表达未发生明显改变;WISP3基因的表达极低。cDNA表达芯片分析结果发现,与正常对照比较,SEDT PA患者的成骨细胞有22个基因表达明显上调,16个基因表达明显下调,这些基因包括有成骨细胞的标记分子、细胞外基 相似文献
88.
Liang Wang Nan Dai Dingrong Chen Airui Jiang Guobin Liao Chaoqiang Fan Xin Yang Xue Peng Xubiao Nie Hui Lin En Liu Xi Liu Xinwei Diao Jianying Bai 《American journal of cancer research》2022,12(4):1855
Little is known about esophageal high-grade intraepithelial neoplasia dominated by cytological atypia (HGINc). We aimed to elucidate the endoscopic features of HGINc compared with esophageal high-grade intraepithelial neoplasia dominated by architectural atypia (HGINa). All patients pathologically diagnosed as esophageal high-grade intraepithelial neoplasia after endoscopic submucosal dissection at our center between January 2018 and December 2019 were included in this study. According to the pathological diagnosis, the patients were divided into two groups: HGINa group and HGINc group. Basic characteristics and endoscopic information were collected in detail. Data were analyzed statistically. Binary logistic regression was performed and a predictive model for HGINc was established. Then we evaluated its predictive value and built a nomogram for clinical application. A total of 175 patients were included in this study (126 with HGINa and 49 with HGINc). Among 228 lesions found in all patients, there were 148 HGINa and 80 HGINc. The independent relevant factors for HGINc were tobacco and alcohol usage, color, and gross type. To predict risk of HGINc, a three-factor model (TFM) was established with a highest area under curve (AUC) as 0.869 (95% CI, 0.852, 0.939). When the cut-off value was set as 0.3569184, the diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for HGINc was 81.14%, 88.75%, 77.03%, 67.62%, and 92.68%, respectively. HGINc differs greatly in endoscopic features from HGINa in our study. It’s important to reduce misdiagnosis that our model was established with good predictive value for clinical application. 相似文献
89.
目的 研究血管内皮抑素转基因双歧杆菌口服冻干粉剂(endostatin transfected bifidobacterium oral powder prepara-tion,ETB-2)体外抗肿瘤作用及对大鼠大肠痛的影响.方法 采用MTT法检测ETB-2对人结肠癌细胞株LS-174T、人胃黏膜上皮细胞株GES-1的作用.以二甲肼(DMH)为诱发剂,观察ETB-2对大鼠大肠癌的防治作用;DMH诱癌及ETB-2灌胃时间为18周,在第33周结束实验.结果 ETB-2在体外对人结肠癌细胞株具有显著的选择性杀伤作用,体内给药可明显降低大鼠大肠癌发生率(60%:100%,P<0.01),但大肠癌平均个数及肿瘤体积指数的差异无显著性(P>0.05).结论 ETB-2对DMH诱导的大鼠大肠癌具有预防作用. 相似文献
90.
Before and after general irradiation with ~(60)Co-γ, mice were orally given Sheng Bai Solution (SBS) for one week. SBS alleviated the irradiation-induced reduction of bone marrow cell chromosome division index. The irradiationinduced decrease of marrow DNA amount, thymic and splenic fractions, and total leukocyte number were restored to some extent. SBS also helped to ameliorate general condition of patients. 相似文献