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   26311篇
  免费   2507篇
  国内免费   2174篇
耳鼻咽喉   215篇
儿科学   268篇
妇产科学   367篇
基础医学   3289篇
口腔科学   518篇
临床医学   3631篇
内科学   4061篇
皮肤病学   199篇
神经病学   1536篇
特种医学   980篇
外国民族医学   14篇
外科学   2769篇
综合类   4139篇
现状与发展   8篇
一般理论   4篇
预防医学   1631篇
眼科学   616篇
药学   2896篇
  21篇
中国医学   1532篇
肿瘤学   2298篇
  2025年   10篇
  2024年   365篇
  2023年   562篇
  2022年   1118篇
  2021年   1387篇
  2020年   1072篇
  2019年   923篇
  2018年   877篇
  2017年   886篇
  2016年   773篇
  2015年   1175篇
  2014年   1544篇
  2013年   1272篇
  2012年   1877篇
  2011年   1947篇
  2010年   1278篇
  2009年   989篇
  2008年   1399篇
  2007年   1390篇
  2006年   1271篇
  2005年   1401篇
  2004年   928篇
  2003年   913篇
  2002年   733篇
  2001年   592篇
  2000年   654篇
  1999年   658篇
  1998年   432篇
  1997年   388篇
  1996年   335篇
  1995年   315篇
  1994年   281篇
  1993年   183篇
  1992年   208篇
  1991年   178篇
  1990年   142篇
  1989年   104篇
  1988年   110篇
  1987年   76篇
  1986年   77篇
  1985年   52篇
  1984年   34篇
  1983年   27篇
  1982年   12篇
  1981年   9篇
  1980年   8篇
  1979年   10篇
  1978年   3篇
  1977年   4篇
  1929年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
丁晓明  刘迅 《齐鲁药事》2005,24(11):698-699
患者女,42岁,于2005年4月10日,因尿频、尿急、尿痛2d就诊,查体T 37℃,BP16/9 Kpa,心率68·min-1,心肺未见异常,双下肢无水肿,双侧肾区无叩击痛,既往健康,无药物过敏史,未曾应用过左氧氟沙星。查血常规:WBC10×109L-1、N78%。尿常规,BLD()、GLU()、Pro(+)、WBC()。镜检,WBC 10×15个/HP。临床诊断为,急性泌尿系感染。医嘱给予抗生素治疗。静脉滴注0·9%生理盐水250ml+左氧氟沙星0·3g 30min后,患者感胸闷、伴有大汗、脉搏细弱。询问患者晨起后未进早餐,考虑为低血糖反应。医嘱减慢滴速,多饮水,20min后症状缓解。第二天重复上述药物…  相似文献   
52.
Despite recent progress in the identification and characterization of numerous nasal biotransformation enzymes in laboratory animals, the expression of biotransformation genes in human nasal mucosa remains difficult to study. Given the potential role of nasal biotransformation enzymes in the metabolism of airborne chemicals, including fragrance compounds and therapeutic agents, as well as the potential interspecies differences between laboratory animals and humans, it would be highly desirable to identify those biotransformation genes that are expressed in human nasal mucosa. In this study, a global gene expression analysis was performed to compare biotransformation enzymes expressed in human fetal and adult nasal mucosa to those expressed in liver. The identities of a list of biotransformation genes with apparently nasal mucosa-selective expression were subsequently confirmed by RNA-polymerase chain reaction (PCR) and DNA sequencing of the PCR products. Further quantitative RNA-PCR experiments indicated that, in the fetus, aldehyde dehydrogenase 6 (ALDH6), CYP1B1, CYP2F1, CYP4B1, and UDP glucuronosyltransferase 2A1 are expressed preferentially in the nasal mucosa and that ALDH7, flavin-containing monooxygenase 1, and glutathione S-transferase P1 are at least as abundant in the nasal mucosa as in the liver. The nasal mucosal expression of CYP2E1 was also detected. These findings provide a basis for further explorations of the metabolic capacity of the human nasal mucosa for xenobiotic compounds.  相似文献   
53.
中医医院急诊工作的建议   总被引:1,自引:0,他引:1  
中医医院急诊工作不仅关系着中医医院综合服务功能的完善,而且也是医院可持续发展的标志之一.笔者认为,中医医院急诊工作必须注重以下几个方面.  相似文献   
54.
Background:The diagnosis and treatment rate of Parkinson disease (PD) with depression has a low diagnostic rate, and there is no consensus on the choice of treatment mode. This study evaluates the global research trends of scientific outputs related to depression in PD from multiple perspectives, using a bibliometric analysis and visualization tool to scientifically analyze the knowledge from the literature.Methods:Literature related to depression in PD published from 2012 to 2021 was included and selected from the Web of Science Core Collection database in October 2021. CiteSpace software was used to visualize and analyze co-occurrence analyses for countries, institutions, authors, and keywords.Results:A total of 4533 articles from the Web of Science database were included. The United States made the largest contribution with the majority of publications (1215; 29.40%). Toronto University was the most productive institution. PD, depression, quality of life, dementia, nonmotor symptom, prevalence, anxiety, Alzheimer disease, symptom, and disorder would be significantly correlated with depression in PD. The current hot spots in this field focus on the following: risk factors for depression in PD, assessment scale of depression in PD, and rehabilitation of depression in PD.Conclusions:This analysis not only reveals the current research trends and hotspots but also provides some instructive suggestions on the development of depression in PD.  相似文献   
55.
There is a lack of studies on the association between whole grain intake and cardiometabolic risk factors in China and the current definition of whole grains is inconsistent. This study defined whole grains in two ways, Western versus traditional, and examined their associations with the risks of major cardiometabolic factors (CMFs) among 4706 Chinese adults aged ≥18 years, who participated in surveys both in 2011 and in 2015. Diet data were collected by consecutive 3 d 24 h recalls, together with household seasoning weighing. Whole grains were defined as grains with a ratio of fiber to carbohydrate of ≥0.1, while coarse grains were defined as grains except for rice and its products, and wheat and its products. Multivariable logistic regressions were modeled to analyze the associations of intakes of whole grains and coarse grains, respectively, with risks of major CMFs including obesity-, blood pressure-, blood glucose- and lipid-related factors, which were defined by International Diabetes Federation and AHA/NHLBI criteria. After adjusting for potential confounders, the odds of elevated LDL-C decreased with the increasing intake levels of whole grains (OR 0.64, 95% CI 0.46–0.88, p-trend < 0.05). Moreover, adults with the whole grain intake of 50.00 to 150.00 g/day had 27% lower odds of overweight and obesity (OR 0.73, 95% CI 0.54–0.99) and 31% lower odds of elevated LDL-C (OR 0.69, 95% CI 0.49–0.96), as compared with non-consumers. In conclusion, given the significant nutrient profiles of whole grains and coarse grains, the adults with higher intakes of whole grains only may have a lower risk of LDL-C and overweight and obesity.  相似文献   
56.
Porcine epidemic diarrhea (PED), characterized by diarrhea, vomiting, and dehydration, is an acute enteric infectious disease of pigs. The disease is caused by porcine epidemic diarrhea virus (PEDV), which infects the intestinal mucosal surface. Therefore, mucosal immunization through the oral route is an effective method of immunization. Lactic acid bacteria, which are acid resistant and bile-salt resistant and improve mucosal immunity, are ideal carriers for oral vaccines. The S1 glycoprotein of PEDV mediates binding of the virus with cell receptors and induces neutralizing antibodies against the virus. Therefore, we reversely screened the recombinant strain pPG-SD-S1/Δupp ATCC 393 expressing PEDV S1 glycoprotein by Lactobacillus casei deficient in upp genotype (Δupp ATCC 393). Mice were orally immunized three times with the recombinant bacteria that had been identified for expression, and the changes of anti-PEDV IgG and secreted immunoglobulin A levels were observed over 70 days. The results indicated that the antibody levels notably increased after oral administration of recombinant bacteria. The detection of extracellular cytokines on the 42nd day after immunization indicated high levels of humoral and cellular immune responses in mice. The above results demonstrate that pPG-SD-S1/Δupp ATCC 393 has great potential as an oral vaccine against PEDV.  相似文献   
57.
In this paper, the phase structure, composition distribution, grain morphology, and hardness of Al6061 alloy samples made with additive friction stir deposition (AFS-D) were examined. A nearly symmetrical layer-by-layer structure was observed in the cross section (vertical with respect to the fabrication-tool traversing direction) of the as-deposited Al6061 alloy samples made with a back-and-forth AFS-D strategy. Equiaxed grains were observed in the region underneath the fabrication tool, while elongated grains were seen in the “flash region” along the mass flow direction. No clear grain size variance was discovered along the AFS-D build direction except for the last deposited layer. Grains were significantly refined from the feedstock (~163.5 µm) to as-deposited Al6061 alloy parts (~8.5 µm). The hardness of the as-fabricated Al6061 alloy was lower than those of the feedstock and their heat-treated counterparts, which was ascribed to the decreased precipitate content and enlarged precipitate size.  相似文献   
58.
ContextSchisandra chinensis (Turcz.) Baill. (Magnoliaceae) essential oil (SCEO) composition is rich in lignans that are believed to perform protective effects in the liver.ObjectiveThis study investigates the effects of SCEO in the treatment of acetaminophen (APAP)-induced liver injury in mice.Materials and methodsC57BL/6 mice (n = 56) were randomly divided into seven groups: normal; APAP (300 mg/kg); APAP plus bicyclol (200 mg/kg); APAP plus SCEO (0.25, 0.5, 1, 2 g/kg). Serum biochemical parameters for liver function, inflammatory factors, and antioxidant activities were determined. The protein expression levels of Nrf2, GCLC, GCLM, HO-1, p62, and LC3 were assessed by western blotting. Nrf2, GCLC, HO-1, p62, and LC3 mRNA were detected by real-time PCR.ResultsCompared to APAP overdose, SCEO (2 g/kg) pre-treatment reduced the serum levels of AST (79.4%), ALT (84.6%), TNF-α (57.3%), and IL-6 (53.0%). In addition, SCEO (2 g/kg) markedly suppressed cytochrome P450 2E1 (CYP2E1) (15.4%) and attenuated the exhaustion of GSH (43.6%) and SOD (16.8%), and the accumulation of MDA (22.6%) in the liver, to inhibit the occurrence of oxidative stress. Moreover, hepatic tissues from our experiment revealed that SCEO pre-treatment mitigated liver injury caused by oxidative stress by increasing Nrf2, HO-1, and GCL. Additionally, SCEO activated autophagy, which upregulated hepatic LC3-II and decreased p62 in APAP overdose mice (p < 0.05).Discussion and conclusionsOur evidence demonstrated that SCEO protects hepatocytes from APAP-induced liver injury in vivo and the findings will provide a reliable theoretical basis for developing novel therapeutics.  相似文献   
59.
大鼠静注常咯啉再注射乌头硷,或同时用常咯啉和乌头硷,明显推迟乌头硷引起的心律紊乱。先静注乌头硷出现心律失常后,再注射常咯啉,抗心律失常作用较弱。剪断二侧迷走神经,或静注六烃季铵,都不影响常咯啉抗静注乌头硷所致心律失常的疗效。从静脉恒速注射乌头硷,记录室性早搏、室性心动过速和心室颤动阈值。预先静脉注射常咯啉明显提高这三种阈值。利血平化加常咯啉组,这些阀值也比对照组明显提高,与常咯啉组相比,仅显著提高心室颤动阈值。脑室内注射常咯啉后,再脑室内注射乌头硷,明显推迟心律失常出现时间。常咯啉对大鼠坐骨神经的局麻作用甚微,这与利多卡因有明显不同。  相似文献   
60.
目的:观察中药对高葡萄糖条件下与内皮细胞(以下简称EC)共培养的雪旺细胞(以下简称SC)凋亡的干预作用。方法:建立大鼠SC与EC的共培养模型,根据存活率(形态学和MTT)筛选药物最有效作用浓度。将细胞分为正常共培养SC组、高糖共培养SC组、高糖黄芪组、高糖丹参组、高糖山药组、高糖复方组,通过凋亡率(流式细胞仪)和凋亡相关基因Bcl-2和Casepase-3的mRNA(Realtime PCR)和蛋白(Western Blot)的表达观察细胞凋亡。结果:与正常共培养组相比高糖共培养组SC凋亡率明显增高、Bcl-2mRNA和蛋白表达量明显减少,Casepase-3mRNA和蛋白表达量显著增加。加中药干预后SC凋亡率都明显降低,Bcl-2mRNA和蛋白表达量都明显增加,除高糖山药组Casepase-3mRNA减少和高糖丹参组Casepase-3蛋白减少无明显统计学意义,其余各组Casepase-3mRNA和蛋白表达量均显著减少。中药干预组之间比较,高糖复方组作用最显著。中药干预组与正常组相比,SC凋亡率无明显增高,Bcl-2mRNA和蛋白表达量明显减少,Casepase-3mRNA和蛋白表达量显著增加。结论:中药对高糖环境下与内皮细胞共培养的雪旺细胞的凋亡有保护作用,不同中药作用效果不同,复方效果最佳。  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