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   14409篇
  免费   956篇
  国内免费   456篇
耳鼻咽喉   182篇
儿科学   454篇
妇产科学   203篇
基础医学   1670篇
口腔科学   295篇
临床医学   1429篇
内科学   2989篇
皮肤病学   277篇
神经病学   925篇
特种医学   471篇
外国民族医学   2篇
外科学   1488篇
综合类   1247篇
一般理论   2篇
预防医学   1152篇
眼科学   482篇
药学   1131篇
  6篇
中国医学   405篇
肿瘤学   1011篇
  2024年   24篇
  2023年   130篇
  2022年   264篇
  2021年   470篇
  2020年   314篇
  2019年   379篇
  2018年   552篇
  2017年   393篇
  2016年   388篇
  2015年   509篇
  2014年   610篇
  2013年   716篇
  2012年   1052篇
  2011年   1130篇
  2010年   702篇
  2009年   488篇
  2008年   795篇
  2007年   797篇
  2006年   708篇
  2005年   741篇
  2004年   638篇
  2003年   605篇
  2002年   565篇
  2001年   465篇
  2000年   496篇
  1999年   388篇
  1998年   116篇
  1997年   98篇
  1996年   101篇
  1995年   91篇
  1994年   52篇
  1993年   53篇
  1992年   143篇
  1991年   118篇
  1990年   102篇
  1989年   107篇
  1988年   90篇
  1987年   75篇
  1986年   66篇
  1985年   50篇
  1984年   38篇
  1983年   23篇
  1982年   13篇
  1981年   9篇
  1980年   11篇
  1979年   14篇
  1977年   12篇
  1973年   9篇
  1970年   9篇
  1965年   8篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
The objective of the study was to report clinical outcomes and patterns of failure for these patients with cervical esophageal squamous cell carcinoma (CESCC) treated with intensity-modulated radiotherapy (IMRT). A total of 64 patients with CESCC treated with definitive IMRT from May 2005 to March 2012 in our center were analyzed. Forty-two patients received radiotherapy alone and 22 patients received concurrent chemoradiotherapy. The location and extent of locoregional failures were transferred to the pretreatment planning computed tomography for dosimetry analysis. For all patients, the overall 2-year local failure-free survival, regional failure-free survival, distant failure-free survival, and overall survival rate was 74.5, 88.0, 66.6 and 42.5 %, respectively. Twenty-eight patients had developed treatment failure. Of the 28 patients, 14, 5, and 18 had developed local failure, regional failure, and distant metastasis, respectively. All of the 14 local failures were considered in-field failures. Of the five regional failures, three were considered in-field failures and two were marginal failures. The most frequently observed acute toxicity was mainly Grade 1 or 2. The incidence of acute Grade 3 mucositis (including pharyngitis), skin reaction, and leukopenia was 4.7, 12.5 and 10.9 %, respectively. IMRT provides satisfactory locoregional control for CESCC. Distant metastasis remains the predominate pattern of failure and the predominate pattern of locoregional failures is in-field failure.  相似文献   
92.
In an Italian case-control study of oral cancer, number of missing teeth and other aspects of dental care were similar, but the general condition of the mouth, as indicated by gum bleeding, tartar deposits and mucosal irritation, was worse among oral cancer cases than controls. No differences were detected in sexual practices (including oral sex) and (previous) sexually transmitted infections.  相似文献   
93.
94.
目的:探讨原花青素(PC)对脑缺血再灌注损伤大鼠核转录因子-κB p65(NF-κB p65 )和脑梗死体积的影响.方法:将大鼠随机分为假手术组、缺血再灌注组、PC低剂量治疗组和PC高剂量治疗组,线栓法建立局灶性脑缺血再灌注模型.各组于缺血90min再灌注24h用免疫组化法观察大鼠额顶部皮质NF-κB p65蛋白表达,并进行2,3,5-三苯基氯化四氮唑(TTC)染色观察脑梗死体积.结果:①假手术组及缺血再灌注组的未缺血侧大脑半球可见少量NF-κB p65表达于胞质, 缺血再灌注组NF-κB p65表达发生核移位,于胞核表达增加;与缺血再灌注组比较,PC高、低剂量治疗组能减少NF-κB p65的核表达(P<0.05);高、低剂量组之间差异亦具有统计学意义(P<0.05).②PC高、低剂量治疗组脑梗死体积较缺血再灌注组减小,高、低剂量组之间差异具有显著性(P<0.05).结论:PC对缺血再灌注脑损伤具有保护作用,其机制可能与通过抑制NF-κB p65活化有关.  相似文献   
95.
Dedifferentiated liposarcoma (DDLPS) is a rare subtype of liposarcoma with a poor prognosis. This current case report describes a rectal DDLPS in a 68-year-old Chinese male that presented with lower abdominal pain and weight loss. Computed tomography and magnetic resonance imaging were undertaken to evaluate the tumour. The patient underwent radical resection of the rectal tumour, sigmoid colostomy and partial ureterectomy. The tumour was positive for mouse double minute 2 by immunohistochemistry. The patient healed well but refused chemotherapy postoperatively for economic reasons. The tumour recurred and metastasized 4 weeks after the operation. After relevant treatment, the patient''s condition deteriorated and he died of shock, metabolic acidosis, hyperlactataemia and acute renal failure. The case report also reviews the literature in terms of the clinical diagnosis, treatment and pathological characteristics of rectal DDLPS with the aim of improving the level of diagnosis and treatment.  相似文献   
96.
Primary liver cancer, mainly comprising hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), remains a major global health problem. Although ICC is clinically different from HCC, their molecular differences are still largely unclear. In this study, precision N‐glycoproteomic analysis was performed on both ICC and HCC tumors as well as paracancer tissues to investigate their aberrant site‐specific N‐glycosylation. By using our newly developed glycoproteomic methods and novel algorithm, termed ‘StrucGP’, a total of 486 N‐glycan structures attached on 1235 glycosites were identified from 894 glycoproteins in ICC and HCC tumors. Notably, glycans with uncommon LacdiNAc (GalNAcβ1‐4GlcNAc) structures were distinguished from their isomeric glycans. In addition to several bi‐antennary and/or bisecting glycans that were commonly elevated in ICC and HCC, a number of LacdiNAc‐containing, tri‐antennary, and core‐fucosylated glycans were uniquely increased in ICC. More interestingly, almost all LacdiNAc‐containing N‐glycopeptides were enhanced in ICC tumor but not in HCC tumor, and this phenomenon was further confirmed by lectin histochemistry and the high expression of β1‐4 GalNAc transferases in ICC at both mRNA and protein expression levels. The novel N‐glycan alterations uniquely detected in ICC provide a valuable resource for future studies regarding to the discovery of ICC diagnostic biomarkers, therapeutic targets, and mechanism investigations.  相似文献   
97.
目的观察两种不同含钠浓度的电解质溶液对小儿烧伤液体复苏后机体内环境的影响。方法选择40例年龄6个月至两岁的小儿烧伤病例,烧伤面积从25%~54%,随机分成俩组,每组20例,A组采用平衡盐溶液(A组含钠量130mmol/L),B组采用高钠复方乳酸钠溶液(含钠量174mmol/L),两种不同的电解质溶液行液体复苏。并分别于伤后1~4天抽取血标本检测K 、Na 、Cl-和HCO3-四种电解质,记录各时段液体输入量和尿量以及血浆晶体渗透压等。结果A组伤后第一天的补液量明显高于B组,且A组血清Na 、HCO3-浓度明显下降,伤后第二天逐步回升。A、B两组K 浓度于伤后第三、第四天明显下降。结论电解质溶液中钠离子浓度的不同对小儿烧伤机体内环境的影响较大,含钠量高的溶液可能更有利于烧伤小儿机体内环境保持稳定。  相似文献   
98.
99.
目的:分离培养小鼠骨髓间充质干细胞,研究其体外培养的生物特性。方法:获取骨髓间充质干细胞进行培养,倒置相差显微镜观察细胞生长情况。绘制生长曲线,冷冻保存细胞复苏后的生长状况观察。免疫细胞化学法鉴定细胞表面抗原。在地塞米松、β-甘油磷酸钠、抗坏血酸的作用下,进行成骨诱导分化。结果:原代和传代培养的细胞体外培养细胞呈现梭形、多角形外观,具有较强的生长增殖能力,复苏细胞生长状况无明显改变;细胞CD44。CD54抗原有阳性表达,CD34呈阴性表达。分化细胞表现成骨细胞特性,合成碱性磷酸酶(ALP)能力增强,矿化结节逐渐出现。结论:建立稳定可靠的分离培养小鼠骨髓MSCs方法,分离出的MSCs具有干细胞的生物特性,可用于骨组织工程中的种子细胞。  相似文献   
100.
In our previous research, Lactiplantibacillus plantarum-12 alleviated inflammation in dextran sodium sulfate (DSS)-induced mice by regulating intestinal microbiota and preventing colon shortening (p < 0.05). The purpose of the present study was to evaluate whether L. plantarum-12 could ameliorate the colon cancer symptoms of azoxymethane (AOM)/DSS-treated C57BL/6 mice. The results showed that L. plantarum-12 alleviated colonic shortening (from 7.43 ± 0.15 to 8.23 ± 0.25) and weight loss (from 25.92 ± 0.21 to 27.75 ± 0.88) in AOM/DSS-treated mice. L. plantarum-12 oral administration down-regulated pro-inflammatory factors TNF-α (from 350.41 ± 15.80 to 247.72 ± 21.91), IL-8 (from 322.19 ± 11.83 to 226.08 ± 22.06), and IL-1β (111.43 ± 8.14 to 56.90 ± 2.70) levels and up-regulated anti-inflammatory factor IL-10 (from 126.08 ± 24.92 to 275.89 ± 21.87) level of AOM/DSS-treated mice. L. plantarum-12 oral administration restored the intestinal microbiota dysbiosis of the AOM/DSS treated mice by up-regulating beneficial Muribaculaceae, Lactobacillaceae, and Bifidobacteriaceae levels and down-regulating pathogenic Proteobacteria, Desulfovibrionaceae, and Erysipelotrichaceae levels. As a result, the fecal metabolites of the AOM/DSS-treated mice were altered, including xanthosine, uridine, 3,4-methylenesebacic acid, 3-hydroxytetradecanedioic acid, 4-hydroxyhexanoylglycine, beta-leucine, and glycitein, by L. plantarum-12 oral administration. Furthermore, L. plantarum-12 oral administration significantly ameliorated the colon injury of the AOM/DSS-treated mice by enhancing colonic tight junction protein level and promoting tumor cells death via down-regulating PCNA (proliferating cell nuclear antigen) and up-regulating pro-apoptotic Bax. (p < 0.05). Taken together, L. plantarum-12 oral administration could ameliorate the colon cancer burden and inflammation of AOM-DSS-treated C57BL/6 mice through regulating the intestinal microbiota, manipulating fecal metabolites, enhancing colon barrier function, and inhibiting NF-κB signaling. These results suggest that L. plantarum-12 might be an excellent probiotic candidate for the prevention of colon cancer.  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