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   4476篇
  免费   296篇
  国内免费   85篇
耳鼻咽喉   1篇
儿科学   73篇
妇产科学   23篇
基础医学   418篇
口腔科学   16篇
临床医学   294篇
内科学   2389篇
皮肤病学   13篇
神经病学   81篇
特种医学   61篇
外科学   397篇
综合类   176篇
现状与发展   2篇
一般理论   1篇
预防医学   240篇
眼科学   7篇
药学   288篇
  1篇
中国医学   152篇
肿瘤学   224篇
  2024年   4篇
  2023年   308篇
  2022年   410篇
  2021年   466篇
  2020年   424篇
  2019年   231篇
  2018年   177篇
  2017年   206篇
  2016年   197篇
  2015年   200篇
  2014年   381篇
  2013年   236篇
  2012年   194篇
  2011年   147篇
  2010年   162篇
  2009年   187篇
  2008年   75篇
  2007年   99篇
  2006年   101篇
  2005年   71篇
  2004年   51篇
  2003年   62篇
  2002年   61篇
  2001年   38篇
  2000年   37篇
  1999年   50篇
  1998年   45篇
  1997年   29篇
  1996年   31篇
  1995年   32篇
  1994年   21篇
  1993年   17篇
  1992年   24篇
  1991年   18篇
  1990年   17篇
  1989年   18篇
  1988年   9篇
  1987年   3篇
  1986年   1篇
  1985年   4篇
  1984年   2篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1976年   1篇
  1974年   2篇
  1973年   1篇
排序方式: 共有4857条查询结果,搜索用时 15 毫秒
1.
《Clinical therapeutics》2022,44(3):403-417.e6
PurposeEntecavir (ETV) and tenofovir disoproxil fumarate (TDF) are both recommended as first-line treatments for patients with chronic hepatitis B virus (CHB) infection according to international HBV treatment guidelines. However, recent studies reported conflicting results regarding the preferred antiviral in the prevention of hepatocellular carcinoma (HCC). This cohort study aimed to investigate this issue by using Taiwan's National Health Insurance Research Database, wherein a “finite” but not life-long treatment policy was applied.MethodsFrom January 2008 to December 2013, a total of 12,388 consecutive adult patients with CHB who received a finite course of TDF treatment (n = 1250) or ETV treatment (n = 11,138) were analyzed through screening for study eligibility followed by the 1:4 propensity score matching method.FindingsIn the entire cohort, the annual incidence and survival between the ETV and TDF groups were not significantly different regarding HCC occurrence (2.05 vs 2.74 per 100 patient-years [PY]; P = 0.055; hazard ratio [HR], 0.975; log-rank, P = 0.966), cirrhosis-related complications (1.9 vs 2.4 per 100 PY; P = 0.149; HR, 0.869; log-rank, P = 0.388), or all-cause mortality (2.16 vs 1.6 per 100 PY; P = 0.119; HR, 0.831; log-rank, P = 0.342), respectively. Propensity score matching analyses yielded similar results regarding HCC occurrence, cirrhosis-related complications, and all-cause mortality. In addition, these findings were consistently reproduced in the subgroups of patients with chronic hepatitis and cirrhosis that developed before antiviral treatment.ImplicationsETV and TDF did not significantly differ in prevention of HCC occurrence or reduction of cirrhosis-related complications and all-cause mortality in patients with CHB receiving a finite period of treatment.  相似文献   
2.
Although methadone is effective in the management of acute pain, the complexity of its absorption-distribution-metabolism-excretion profile limits its use as an opioid of choice for perioperative analgesia. Because deuteration is known to improve the pharmacokinetic, pharmacodynamic and toxicological properties of some drugs, here we characterized the single dose pharmacokinetic properties and post-operative analgesic efficacy of d9-methadone.The pharmacokinetic profiles of d9-methadone and methadone administered intravenously to CD-1 male mice revealed that deuteration leads to a 5.7- and 4.4-fold increase in the area under the time-concentration curve and maximum concentration in plasma, respectively, as well as reduction in clearance (0.9 ± 0.3 L/h/kg vs 4.7 ± 0.8 L/h/kg). The lower brain-to-plasma ratio of d9-methadone compared to that of methadone (0.35 ± 0.12 vs 2.05 ± 0.62) suggested that deuteration decreases the transfer of the drug across the blood-brain barrier. The estimated LD50 value for a single intravenous dose of d9-methadone was 2.1-fold higher than that for methadone. Moreover, d9-methadone outperformed methadone in the efficacy against postoperative pain by primarily activating peripheral opioid receptors. Collectively, these data suggest that the replacement of three hydrogen atoms in three methyl groups of methadone altered its pharmacokinetic properties, improved safety, and enhanced its analgesic efficacy.  相似文献   
3.
4.
5.
6.
BackgroundAlcoholic fatty liver disease (AFLD) is a liver disease caused by prolonged heavy drinking and has a poor prognosis in the clinic. This study aimed to explore the differential miRNAs expression profiles in the AFLD rat model.MethodsThe rat model of AFLD was established by ethanol intragastric administration and was used to explore the differential miRNAs expression profiles. We further analyzed the potential target mRNAs using the bioinformatics technique. GO and KEGG pathway enrichment analyses were carried out to better understand the biological function of differential expression genes (DEGs). We used the human Gene Expression Omnibus (GEO) dataset GSE28619 to further screen the key differentially expressed genes. The integration between the differentially expressed genes from the AFLD model and GEO was conducted and the key genes were identified.ResultsThe serum ALT, AST, TG, and TC levels in the AFLD model group were significantly higher than those in the normal control group. There are 45 miRNAs with significant changes including 26 upregulated and 19 down-regulated miRNAs. GO and KEGG enrichment showed various metabolic processes and signaling pathways were enriched in the progression of AFLD. After integrating the results of GSE28619 and DEGs, we observed that there are 12 genes with significant changes in two data sets, including PSAT1, TKFC, PTTG1, LCN2, CXCL1, NR4A1, RGS1, VCAN, FOS, CXCL10, ATF3, and CYP1A1.ConclusionAFLD showed differentially expressed miRNAs, which may be involved in the occurrence and progression of AFLD. Meanwhile, some signal metabolic pathways may be related to the pathogenesis of AFLD.  相似文献   
7.
PurposeTo investigate the safety of yttrium-90 radioembolization in combination with checkpoint inhibitor immunotherapy for the treatment of hepatocellular carcinoma (HCC).Materials and MethodsThis single-center retrospective study included 26 consecutive patients with HCC who received checkpoint inhibitor immunotherapy within 90 days of radioembolization from April 2015 to May 2018. Patients had preserved liver function (Child-Pugh scores A–B7) and either advanced HCC due to macrovascular invasion or limited extrahepatic disease (21 patients) or aggressive intermediate stage HCC that resulted in earlier incorporation of systemic immunotherapy (5 patients). Clinical documentation, laboratory results, and imaging results at 1- and 3-month follow-up intervals were reviewed to assess treatment-related adverse events and treatment responses.ResultsThe median follow-up period after radioembolization was 7.8 months (95% confidence interval [CI], 5.6–11.8). There were no early (30-day) mortality or grades 3/4 hepatobiliary or immunotherapy-related toxicities. Delayed grades 3/4 hepatobiliary toxicities (1–3 months) occurred in 2 patients in the setting of HCC disease progression. One patient developed pneumonitis. The median overall survival from first immunotherapy was 17.2 months (95% CI, 10.9–23.4). The median overall survival from first radioembolization was 16.5 months (95% CI, 6.6–26.4). From first radioembolization, time to tumor progression was 5.7 months (95% CI, 4.2–7.2), and progression-free survival was 5.7 months (95% CI, 4.3–7.1).ConclusionsRadioembolization combined with checkpoint inhibitor immunotherapy in cases of HCC appears to be safe and causes limited treatment-related toxicity. Future prospective studies are needed to identify the optimal combination treatment protocols and evaluate the efficacy of combination therapy.  相似文献   
8.
9.
《Digestive and liver disease》2020,52(12):1430-1442
Currently, the only curative treatment for cholangiocarcinoma (CCA) is surgical resection, though this treatment is possible in less than 40% of patients. However, recent improvements in preoperative management have led to a higher number of patients who are candidates for this procedure. For unresectable patients, progress is ongoing in terms of locoregional and chemoradiation treatments and target therapies, especially in the definition of patient selection criteria. This is the second part of the Italian CCA guidelines, dealing with CCA treatment, that have been formulated in accordance with Italian National Institute of Health indications and developed according to the GRADE method and related advancements.  相似文献   
10.
The activation of hepatic stellate cells (HSCs) plays a critical role in the development of liver fibrosis. The induction of apoptosis in activated HSCs during the recovery phase of hepatic fibrosis represents a potential anti-fibrotic therapy. We have previously shown that Smad2 protects against hepatic fibrogenesis; however, the role of Smad2 in the regulation of activated HSC apoptosis remains unknown. We hypothesized that Smad2 regulates the apoptosis of activated HSCs, leading to the resolution of liver fibrosis. To test this hypothesis, the livers of rats were harvested at 0 and 4 weeks after hepatic fibrosis was established by CCl4 injection. Furthermore, TGF-β1-activated HSCs were treated with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) following the silencing or overexpression of Smad2. Both the phosphorylation of Smad2 and TRAIL were detected in fibrotic liver tissues. The results of TUNEL and α-SMA double-staining showed an increase in the apoptosis of activated HSCs during the spontaneous recovery phase. The knockdown of Smad2 reduced TRAIL-induced apoptosis in TGF-β1-activated human LX-2 cells and resulted in an increased expression of α-SMA and collagen I (Col. I). In contrast, the overexpression of Smad2 increased TRAIL-induced HSC apoptosis and reduced the expression of α-SMA and Col. I. The mechanisms underlying these findings were associated with the Smad2-mediated down-regulation of X-linked inhibitor of apoptosis protein (XIAP), resulting in enhanced caspase-3 activity and apoptosis. In conclusion, Smad2 enhances TRAIL-induced apoptosis in activated HSCs, which facilitates the resolution of hepatic fibrosis.  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