首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   17588篇
  免费   1311篇
  国内免费   565篇
耳鼻咽喉   43篇
儿科学   404篇
妇产科学   327篇
基础医学   2444篇
口腔科学   338篇
临床医学   1783篇
内科学   2193篇
皮肤病学   200篇
神经病学   677篇
特种医学   291篇
外国民族医学   2篇
外科学   845篇
综合类   2940篇
现状与发展   1篇
预防医学   1292篇
眼科学   182篇
药学   3237篇
  17篇
中国医学   1346篇
肿瘤学   902篇
  2023年   171篇
  2022年   270篇
  2021年   543篇
  2020年   528篇
  2019年   504篇
  2018年   486篇
  2017年   582篇
  2016年   612篇
  2015年   561篇
  2014年   1008篇
  2013年   1221篇
  2012年   917篇
  2011年   1111篇
  2010年   846篇
  2009年   687篇
  2008年   696篇
  2007年   745篇
  2006年   730篇
  2005年   622篇
  2004年   565篇
  2003年   514篇
  2002年   460篇
  2001年   351篇
  2000年   292篇
  1999年   219篇
  1998年   229篇
  1997年   217篇
  1996年   192篇
  1995年   215篇
  1994年   225篇
  1993年   209篇
  1992年   199篇
  1991年   173篇
  1990年   161篇
  1989年   157篇
  1988年   129篇
  1987年   153篇
  1986年   99篇
  1985年   356篇
  1984年   268篇
  1983年   241篇
  1982年   200篇
  1981年   189篇
  1980年   137篇
  1979年   95篇
  1978年   85篇
  1977年   66篇
  1976年   48篇
  1975年   39篇
  1973年   33篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
1.
目的:探讨胃癌患者根治术后腹腔冲洗液中CEA mRNA表达情况及其临床意义。方法: 回顾性分析了2013 年1 月至2017 年12 月在南京大学医学院附属鼓楼医院接受胃癌根治切除术后进行腹腔灌洗液CEA mRNA检测的139 名患者的病历资料,并进行术后常规随访。用RT-PCR检测139 胃癌患者根治术后腹腔灌洗液中CEA mRNA表达情况。卡方检验分析腹腔灌洗液中CEA mRNA表达与临床基本特征、组织病理学资料、血液学指标及复发方式之间的关系。采用Logistic 单因素及多因素回归分析筛查影响CEA mRNA表达水平的因素。结果:139 名患者中44 名(31.7%)患者腹腔灌洗液CEA mRNA阳性。分析显示,胃癌患者腹腔灌洗液CEA mRNA阳性表达与性别、年龄、病理分级、Lauren 分型和HER2、EGFR、VEGFR等标记物间均没有明显的关联(均P>0.05),与病理类型、脉管是否侵犯、局部浸润深度、淋巴结转移程度和临床AJCC 分期有明显的关联(均P<0.05)。CEA mRNA阳性患者腹膜复发率明显高于阴性患者(P=0.012)。Logistic 单因素回归分析显示,印戒细胞癌(P=0.04,HR=2.810,95% CI: 1.050~7.520)、T 分期(P=0.016,HR=6.329,95% CI: 1.417~28.264)、N 分期(P=0.022,HR=3.068,95% CI: 1.172~8.027)、AJCC分期(P=0.016 ,HR=3.971 ,95% CI: 1.295~12.173 )、神经侵犯(P=0.002 ,HR=6.738,95% CI: 1.995~22.757)、脉管侵犯(P<0.001,HR=16.36,95% CI: 3.85~69.512)为胃癌患者腹腔灌洗液CEA mRNA阳性表达的危险因素。Logistic 多因素回归分析显示,经过对其他因素的校正,脉管侵犯(P<0.001,HR=21.314,95% CI: 4.21~107.907)为胃癌患者腹腔灌洗液CEA mRNA阳性表达的独立危险因素。结论:胃癌腹腔灌洗CEA mRNA阳性的患者腹膜复发转移风险高且预后不良,应考虑包括腹腔局部治疗在内的更加积极的抗肿瘤治疗。  相似文献   
2.
目的探讨乙肝孕妇血清标志物模式、HBV-DNA载量及肝功能三者之间的关系,为孕期乙肝病毒感染情况的监控和乙肝病毒母婴传播的预防提供参考。方法选取2019年1月-11月在我院产检的767例乙肝表面抗原阳性孕妇的乙肝血清标志物模式、肝功能指标的丙氨酸氨基转移酶(alamine aminotransferase,ALT)及HBVDNA载量进行研究,探讨三者间的关系。结果HBsAg、HBeAg、HBcAb阳性组孕妇HBV-DNA阳性率及病毒载量均高于其余两组(P<0.05);ALT升高程度与HBV-DNA载量具有一定相关性(r=0.255,χ^2=80.150,P=0.000);HBeAg阳性组和HBeAg阴性组间HBV-DNA阳性率、ALT异常率差异均有统计学意义。结论HBV-M、HBV-DNA与肝功能之间有一定的相关性,大三阳孕妇中高病毒载量比例高,应加强乙肝孕妇孕期各项指标的监测,必要时进行干预治疗。  相似文献   
3.
目的 探讨丹青胶囊联合他扎罗汀倍他米松治疗银屑病的临床疗效.方法 选取2019年6月—2021年6月在天津市职业病防治院门诊皮肤科就诊治疗的114例银屑病患者,根据随机数字法分为对照组和治疗组,每组各57例.对照组患者给予他扎罗汀倍他米松乳膏,洗净患处,待皮肤干爽后,将适量本品均匀涂抹于患处,1次/d.治疗组患者在对照组治疗基础上口服丹青胶囊,4粒/次,3次/d.两组患者均连续治疗7 d.观察两组患者的临床疗效和临床症状好转时间,比较两组治疗前与治疗1、4、8周的皮损面积和严重程度指数(PASI)评分和血清炎性因子水平.结果 治疗后,治疗组总有效率是98.25%,显著高于对照组的82.46%(P<0.05).治疗后,治疗组患者皮损暗红、皮损肥厚、皮肤瘙痒、皮肤疼痛等症状好转时间均显著短于对照组(P<0.05).治疗后,两组PASI评分均较治疗前显著降低(P<0.05);治疗1、4、8周治疗组PASI评分显著低于对照组(P<0.05).治疗后,两组患者血清炎性因子白细胞介素6(IL-6)、白细胞介素17(IL-17)、肿瘤坏死因子α(TNF-α)、干扰素-γ(IFN-γ)水平均较治疗前显著降低(P<0.05);治疗后,治疗组血清炎性因子水平显著低于对照组(P<0.05).结论 丹青胶囊联合他扎罗汀倍他米松治疗银屑病效果明显,能显著降低炎性因子水平,并有助于改善皮损情况,值得临床推广应用.  相似文献   
4.
Ovarian carcinoma is one of the most lethal malignancies, but only very few prognostic biomarkers are known. The degradome, comprising proteases, protease non-proteolytic homologues and inhibitors, have been involved in the prognosis of many cancer types, including ovarian carcinoma. The prognostic significance of the whole degradome family has not been specifically studied in high-grade serous ovarian cancer. A targeted DNA microarray known as the CLIP-CHIP microarray was used to identify potential prognostic factors in ten high-grade serous ovarian cancer women who had early recurrence (<1.6 years) or late/no recurrence after first line surgery and chemotherapy. In women with early recurrence, we identified seven upregulated genes (TMPRSS4, MASP1/3, SPC18, PSMB1, IGFBP2, CFI – encoding Complement Factor I – and MMP9) and one down-regulated gene (ADAM-10). Using immunohistochemistry, we evaluated the prognostic effect of these 8 candidate genes in an independent cohort of 112 high-grade serous ovarian cancer women. Outcomes were progression, defined according to CA-125 criteria, and death. Multivariate Cox proportional hazard regression models were done to estimate the associations between each protein and each outcome. High ADAM-10 expression (intensity of 2–3) was associated with a lower risk of progression (adjusted hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.29-0.87). High complement factor I expression (intensity 2–3) was associated with a higher risk of progression (adjusted HR: 2.30, 95% CI: 1.17–4.53) and death (adjusted HR: 3.42; 95% CI: 1.72–6.79). Overall, we identified the prognostic value of two proteases, ADAM-10 and complement factor I, for high-grade serous ovarian cancer which could have clinical significance.  相似文献   
5.
《Vaccine》2021,39(45):6601-6613
AKS-452 is a biologically-engineered vaccine comprising an Fc fusion protein of the SARS-CoV-2 viral spike protein receptor binding domain antigen (Ag) and human IgG1 Fc (SP/RBD-Fc) in clinical development for the induction and augmentation of neutralizing IgG titers against SARS-CoV-2 viral infection to address the COVID-19 pandemic. The Fc moiety is designed to enhance immunogenicity by increasing uptake via Fc-receptors (FcγR) on Ag-presenting cells (APCs) and prolonging exposure due to neonatal Fc receptor (FcRn) recycling. AKS-452 induced approximately 20-fold greater neutralizing IgG titers in mice relative to those induced by SP/RBD without the Fc moiety and induced comparable long-term neutralizing titers with a single dose vs. two doses. To further enhance immunogenicity, AKS-452 was evaluated in formulations containing a panel of adjuvants in which the water-in-oil adjuvant, Montanide™ ISA 720, enhanced neutralizing IgG titers by approximately 7-fold after one and two doses in mice, including the neutralization of live SARS-CoV-2 virus infection of VERO-E6 cells. Furthermore, ISA 720-adjuvanted AKS-452 was immunogenic in rabbits and non-human primates (NHPs) and protected from infection and clinical symptoms with live SARS-CoV-2 virus in NHPs (USA-WA1/2020 viral strain) and the K18 human ACE2-trangenic (K18-huACE2-Tg) mouse (South African B.1.351 viral variant). These preclinical studies support the initiation of Phase I clinical studies with adjuvanted AKS-452 with the expectation that this room-temperature stable, Fc-fusion subunit vaccine can be rapidly and inexpensively manufactured to provide billions of doses per year especially in regions where the cold-chain is difficult to maintain.  相似文献   
6.
1. To investigate Genkwa Flos hepatotoxicity, a cell metabolomics strategy combined with serum pharmacology was performed on human HL-7702 liver cells in this study.

2. Firstly, cell viability and biochemical indicators were determined and the cell morphology was observed to confirm the cell injury and develop a cell hepatotoxicity model. Then, with the help of cell metabolomics based on UPLC-MS, the Genkwa Flos group samples were completely separated from the blank group samples in the score plots and seven upregulated as well as two down-regulated putative biomarkers in the loading plot were identified and confirmed. Besides, two signal molecules and four enzymes involved in biosynthesis pathway of lysophosphatidylcholine and the sphingosine kinase/sphingosine-1-phosphate pathway were determined to investigate the relationship between Genkwa Flos hepatotoxicity and these two classic pathways. Finally, the metabolic pathways related to specific biomarkers and two classic metabolic pathways were analyzed to explain the possible mechanism of Genkwa Flos hepatotoxicity.

3. Based on the results, lipid peroxidation and oxidative stress, phospholipase A2/lysophosphatidylcholine pathway, the disturbance of sphingosine-1-phosphate metabolic profile centered on sphingosine kinase/sphingosine-1-phosphate pathway and fatty acid metabolism might be critical participators in the progression of liver injury induced by Genkwa Flos.  相似文献   

7.
侯万举  曹洁  王娟 《天津医药》2019,47(2):155-158
目的 研究血清窖蛋白-1 (Cav-1) 在慢性阻塞性肺疾病 (COPD) 相关肺动脉高压 (PAH) 患者中的表达及其意义。方法 选取稳定期COPD患者65例, 根据是否合并PAH分成COPD组 [肺动脉收缩压 (PASP) <40 mmHg, 35例] 及COPD-PAH组 (PASP ≥40 mmHg, 30例)。另选取在本院健康体检的志愿者30例作为对照组。对比各组基线资料、 动脉血气分析、 肺功能指标, 以及血清Cav-1、 白细胞介素 (IL) -6和肿瘤坏死因子-α (TNF-α) 的表达水平。绘制受试者工作特征 (ROC) 曲线, 评价Cav-1对COPD合并PAH的诊断价值。结果 COPD-PAH组与COPD组第一秒用力呼吸容积 (FEV1) /用力肺活量 (FVC)、 FEV1占预计值百分比 (FEV1%) 及氧分压 [p (O2 )] 低于对照组, 而二氧化碳分压 [p (CO2 )]、 PASP均高于对照组 (P<0.01)。COPD-PAH组p (O2 ) 低于COPD组, p (CO2 )、 PASP均高于COPD 组 (P<0.01)。对照组、 COPD组及COPD-PAH组Cav-1表达水平呈逐渐降低趋势, 而IL-6、 TNF-α表达水平呈逐渐升高趋势 (P<0.01)。血清Cav-1诊断COPD合并PAH的ROC曲线下面积为0.902 (0.821~0.955), 最佳截断值为 6.66 μg/L, 此时诊断敏感度为76.7%, 特异度为85.7%, 与多普勒超声诊断仪测量PASP结果比较一致性较好 (Kappa 值=0.627)。结论 血清Cav-1在COPD相关PAH患者表达明显下调, 可以作为预测COPD相关PAH的新型血清标志物。  相似文献   
8.
Objectives: To examine the factors associated with increase in lumbar spine bone mineral density (LS-BMD) by bisphosphonates (BPs) with active vitamin D analog (aVD).

Methods: Two independent postmenopausal osteoporotic patients treated by BPs with aVD for 24 months (Study 1: n?=?93, Study 2: n?=?99) were retrospectively analyzed.

Results: In Study 1, LS-BMD of the patients significantly increased for 24 m (5.4%, p?r2: 0.088, p?=?.02). While average sCa of the patients was 9.2?mg/dL before treatment, it increased time-dependently to 9.6?mg/dL for 24 m by treatment. As each patient had their LS-BMD five times during the study, there were four instances of %LS-BMD in each patient, resulting in 372 instances of %LS-BMD in Study 1. The smallest Akaike’s information criterion value for the most appropriate cut-off levels of sCa for %LS-BMD by treatment every 6 m was 9.3?mg/dL. The %LS-BMD by treatment for 6 m during 24 m period in patients with sCa ≥9.3?mg/dL (1.5%) was significantly higher than that in patients with sCa <9.3?mg/dL (0.8%, p?=?.038). The results of Study 2 were similar to those of Study 1, confirming the phenomena observed.

Conclusion: sCa was associated with an increased LS-BMD by BPs with aVD.  相似文献   
9.
This study aimed to observe the therapeutic effects of magnesium lithospermate B on acute and chronic colitis induced by dextran sodiumsulfate (DSS) and the role of inflammasome complex (NOD-like receptor protein, NLRP; apoptosis-associated speck-like protein containing, ASC; caspase-1). Establishment of acute and chronic colitis models were by using 5% DSS oral administration in BALB/C male mice. Magnesium lithospermate B (240 mg/kg body weight) was given by subcutaneous injection. Samples were collected for biomarker assay, histological examination, immunohistochemical evaluation and western blot. There was obvious increase in TNF-α level and NLPR3, ASC, and caspase-1 expressions in acute and chronic colitis groups compared with the normal control. Significant decrease of the tumor necrosis factor-α level and the expressions of NLPR3, ASC, and caspase-1 were observed after treatment with magnesium lithospermate B. This study showed that magnesium lithospermate B could be used to treat acute and chronic colitis by inhibiting the activation of the NLRP3/ASC/Caspase-1 pathway.  相似文献   
10.
《药学学报(英文版)》2020,10(7):1294-1308
A great challenge in multi-targeting drug discovery is to identify drug-like lead compounds with therapeutic advantages over single target inhibitors and drug combinations. Inspired by our previous efforts in designing antitumor evodiamine derivatives, herein selective histone deacetylase 1 (HDAC1) and topoisomerase 2 (TOP2) dual inhibitors were successfully identified, which showed potent in vitro and in vivo antitumor potency. Particularly, compound 30a was orally active and possessed excellent in vivo antitumor activity in the HCT116 xenograft model (TGI = 75.2%, 150 mg/kg, p.o.) without significant toxicity, which was more potent than HDAC inhibitor vorinostat, TOP inhibitor evodiamine and their combination. Taken together, this study highlights the therapeutic advantages of evodiamine-based HDAC1/TOP2 dual inhibitors and provides valuable leads for the development of novel multi-targeting antitumor agents.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号