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   347篇
  免费   22篇
  国内免费   92篇
儿科学   8篇
妇产科学   19篇
基础医学   36篇
口腔科学   6篇
临床医学   73篇
内科学   107篇
皮肤病学   15篇
神经病学   10篇
特种医学   27篇
外科学   27篇
综合类   18篇
预防医学   9篇
眼科学   13篇
药学   72篇
肿瘤学   21篇
  2022年   1篇
  2021年   2篇
  2020年   4篇
  2019年   5篇
  2018年   7篇
  2017年   8篇
  2016年   5篇
  2015年   7篇
  2014年   11篇
  2013年   11篇
  2012年   8篇
  2011年   9篇
  2010年   17篇
  2009年   13篇
  2008年   10篇
  2007年   62篇
  2006年   18篇
  2005年   19篇
  2004年   4篇
  2003年   5篇
  2002年   3篇
  2001年   6篇
  2000年   14篇
  1999年   11篇
  1998年   24篇
  1997年   12篇
  1996年   13篇
  1995年   20篇
  1994年   24篇
  1993年   13篇
  1992年   11篇
  1991年   11篇
  1990年   14篇
  1989年   9篇
  1988年   10篇
  1987年   5篇
  1986年   6篇
  1985年   5篇
  1984年   1篇
  1983年   2篇
  1981年   1篇
  1980年   2篇
  1978年   5篇
  1977年   3篇
  1976年   4篇
  1975年   1篇
  1973年   2篇
  1970年   2篇
  1969年   1篇
排序方式: 共有461条查询结果,搜索用时 15 毫秒
91.
目的:测量国人全膝关节假体置换术胫骨近端截骨面后缘至腘窝血管之间的距离,以期为临床全膝关节置换术中避免损伤腘窝血管提供参考数据。方法:选择2006-06/12于解放军第二军医大学长征医院体检的50名正常成人(53膝),男29名(31膝),女21名(22膝)。所有观察对象均知情同意,且得到医院伦理道德委员会批准。对所有膝关节进行MRI扫描,在胫骨外侧平台以下10mm水平横断面上辨认腘动静脉,并测量胫骨近端截骨面后缘至腘窝动静脉的距离。结果:53膝全部进入结果分析,无脱落。①男性胫骨近端截骨面后缘至腘动脉、腘静脉平均距离为(6.7±2.5,7.3±2.3)mm,95%可信区间分别为5.8~7.6mm,6.5~8.1mm。②女性胫骨近端截骨面后缘至腘动脉、腘静脉平均距离为(6.6±1.9,7.1±2.7)mm,95%可信区间分别为:5.8~7.4mm,5.9~8.3mm。③不同性别观察对象胫骨近端截骨面后缘至腘血管的距离差异无显著性意义(P>0.05)。结论:腘窝血管紧邻全膝关节假体置换术胫骨近端截骨面后缘,不同性别间无明显差异。全膝关节假体置换术中进行胫骨近端截骨,特别是后方操作时需特别谨慎,以避免损伤腘窝血管。  相似文献   
92.
不同孔径纳米羟基磷灰石人工骨修复兔桡骨缺损效果比较   总被引:4,自引:7,他引:4  
目的:纳米级的羟基磷灰石材料与人体内组织成分更为相似,具有更佳的生物性能。评价不同孔径的多孔纳米羟基磷灰石人工骨的骨缺损修复能力,从而筛选出适合的孔径以达到骨传导功能与生物力学性能的良好统一。方法:实验于2005-10/2006-10在深圳市第二人民医院中心实验室完成。①实验材料:纳米羟基磷灰石人工骨以硝酸钙和磷酸二氢铵为原料,采用溶胶-絮凝法制备粉体,运用压力成型、木模成型和浸渍成型分别制得孔隙分布均匀的孔径分别为50~150μm、100~250μm和300~500μm的多孔纳米羟基磷灰石人工骨。②实验动物:雄性新西兰大白兔60只随机分为植入50~150μm孔径材料组、植入100~250μm孔径材料组、植入300~500μm孔径材料组、空白对照组,每组15只。实验过程中对动物处置符合动物伦理学要求。③实验方法:制备双侧桡骨骨缺损动物模型,然后用3种不同孔径的纳米羟基磷灰石人工骨材料植入骨缺损处进行修复,空白对照组不植入任何材料。④实验评估:术后4,8和12周分别行大体标本观察、X射线片观察、扫描电镜观察及生物力学测试,比较各组材料修复骨缺损的能力。结果:实验动物均进入结果分析。①X射线片检查结果:术后4周、8周、12周,植入100~250μm孔径材料组X射线评分高于植入50~150μm,300~500μm孔径材料组,差异有显著性意义(P<0.05)。②生物力学检测结果:术后4周、8周、12周,植入100~250μm孔径材料组生物力学强度高于植入50~150μm,300~500μm孔径材料组,差异有显著性意义(P<0.05)。③扫描电镜观察结果:植入100~250μm孔径材料组成骨效果明显优于植入50~150μm,300~500μm孔径材料组和空白对照组。结论:纳米羟基磷灰石人工骨具有良好的成骨能力,但其骨修复能力受孔径因素的影响,孔径100~250μm的纳米羟基磷灰石人工骨材料成骨能力较好。  相似文献   
93.
上海市0~6岁小儿佝偻病的现状调查   总被引:14,自引:0,他引:14  
目的:了解上海市小儿佝偻病的现状及影响因素。方法:2005年春季以整群和分层随机抽样法抽取上海市部分城区0~6岁小儿821名,采取问卷调查方法了解小儿的生活环境、饮食习惯、户外活动、营养状况、既往疾病史及母亲的妊娠情况等。佝偻病的诊断以1996年国家卫生部颁布的"婴幼儿佝偻病防治方案"为诊断标准。结果:取得完整有效资料769名,其中男童396名,女童373名;集居儿童456名,散居儿童313名。①小儿佝偻病患病率为17.3%(133/769),其中男童患病率为17.4%、女童为17.2%。②佝偻病与喂养方式(母乳喂养的患病率为13.0%、混合喂养的患病率为17.5%、人工喂养的患病率为25.2%)、鱼肝油添加(按时添加维生素D的患病率为13.5%、偶加或未加维生素D的患病率为32.5%)、居住环境(居住在市区的患病率为23.6%、居住在郊区的患病率为10.6%;集居儿童患病率为13.8%、散居儿童患病率为22.4%)、户外活动时间(经常户外活动的患病率为12.9%、偶尔户外活动的患病率为31.8%)、反复呼吸道感染(小儿有反复呼吸道感染的患病率为26.9%、无反复呼吸道感染的患病率为12.9%)、母孕期缺钙(母孕期有缺钙的患病率为33.2%、无缺钙的患病率为12.0%)等因素有关(P<0.01)。结论:上海市小儿佝偻病患病率有上升趋势。影响因素与城市环境污染、母乳喂养减少、年轻父母科学育儿知识缺乏等有关。  相似文献   
94.
Summary A comparative study of serial anatomic sections in the transverse, frontal and sagittal planes with corresponding MRI sections of the pelvis allowed the authors to define the most suitable sectional planes and MRI modes for a morphologic study of the levator ani muscle. This study shows the value of MRI examination in the assessment of anorectal malformations.
Les muscles elevateurs de l'anus en IRM. Corrélations anatomiques et applications pratiques
Résumé A partir de l'étude comparative de coupes anatomiques dans les plans transversal, frontal, sagittal et des coupes IRM correspondantes du petit bassin, les auteurs déterminent quels sont les plans de coupe et les modes IRM les plus performants pour l'étude morphologique des muscles élévateurs de l'anus. Cette étude montre l'intérêt de l'examen IRM dans le bilan des malformations ano-rectales opérées.
  相似文献   
95.
银耳多糖对小鼠脾细胞内游离钙离子浓度的影响   总被引:10,自引:0,他引:10  
崔金莺  林志彬 《药学学报》1997,32(8):561-564
为进一步探讨银耳多糖(TP)免疫调节作用的机制,建立了特异性荧光探针Fura-2测定脾细胞内游离钙离子浓度的方法,观察TP对脾细胞内游离钙离子浓度的影响。结果表明,TP在一定剂量范围内可以剂量依赖方式增加脾细胞内游离钙离子的浓度,并与ConA有协同作用。在外钙为零时,TP对内钙释放无影响,钙通道阻断剂维拉帕米(verapamil 10μg·mL-1)可阻断TP升高脾细胞内游离钙离子浓度的作用。  相似文献   
96.
A case is reported of an infection with Streptococcus pyogenes, occurring 24 hours after an elective Caesarean section in a 30 year old woman. She worsened during the first 48 h, with shock (Pasys less than 70 mmHg, pH 7.28) as well as abdominal tenderness and guarding. Laparotomy revealed peritonitis, and subtotal hysterectomy was carried out. Gram positive cocci were found in the peritoneal exudate, with bacterial cultures yielding Streptococcus pyogenes. Histopathological examination of the specimen revealed necrosing endomyometritis with septic thrombophlebitis. During the immediate post-operative period, there were several prolonged episodes of circulatory arrest treated with dobutamine, adrenaline, and noradrenaline. Multiple organ failure occurred during the next five days, despite antibiotic therapy (vancomycin, tienamycin, amikacin) and intensive care. It included jaundice, thrombocytopaenia (10 G.l(-1] adult respiratory distress syndrome (ARDS). A further laparotomy was carried out because of abdominal and thigh cellulitis, with completion of the hysterectomy and bilateral salpingo-oophorectomy. Streptococcus pyogenes was still present in the peritoneal cavity. There followed an improvement, with a return to normal of the platelet count, haemodynamic stability such that vasoactive drugs were no longer needed, and a decrease in the degree of jaundice. However, the ARDS worsened, and the patient died 15 days after the Caesarean section. There have been recent reports of similar cases, suggesting an increase in the virulence of group A streptococci linked to a re-emergence of exotoxin A.  相似文献   
97.
Background: Prognosis factors for adenocarcinoma of the uterine cervix after primary treatment are poorly established. Methods: A retrospective study of 45 cases of adenocarcinoma of the cervix with a follow-up of 96 months on average was performed. The primary treatment consisted in combined radical surgery and radiotherapy for stage I-II patients while patients with advanced disease were treated by radiotherapy. In case of poor prognosis factors, they were given chemotherapy. Survival rates were established and prognosis factors influencing survival and recurrences were studied. Results: Fifteen women remained alive without evolutive disease. FIGO stage and pelvic node involvement were the most important parameters influencing overall survival. Local failures (27%, average period of 30 months) were unpredictable and led to a dramatic outcome. Histological grade and pelvic node status were significant predictive factors for metastatic recurrence (40%, average period of 29 months). Conclusions: Local recurrence and metastatic dissemination of cervical adenocarcinoma after primary treatment prove to be rapidly fatal although life expectancy can be prolonged with adjuvant treatment of the recurrence. In the event of aggressive tumors with high histological grade and pelvic node involvement, an attempt to assess adjuvant systemic chemotherapy could be useful.  相似文献   
98.
Baclofen is often prescribed in high doses to fight cravings experienced by alcohol‐dependent patients. Such an increase in the availability of baclofen is concerning. This study aimed to determine the change in number and profile of self‐poisoning with baclofen over time, as baclofen has become increasingly popular, in order to describe the severity of self‐poisoning with baclofen and to focus on co‐existing alcohol use disorders, and psychiatric illnesses determine predictors of severity. This was a retrospective study of self‐poisoning with baclofen as reported by the western France Poison Control Center (PCC), which represents a population of more than 12 million people from January 2008 to March 2014. One hundred and eleven cases of self‐poisoning with baclofen were reported to the western France PCC (62 males and 49 females; average age 39 ± 12). Poisoning severities were as follows: ‘null’ (nine cases), ‘minor’ (37 cases), ‘moderate’ (19 cases) and ‘high’ (46 cases, including four deaths). The most frequently reported symptoms were neurological (45%) and cardiovascular (27%). The severity was significantly associated with psychiatric disorders (OR = 2.9; p = 0.03). Baclofen, prescribed in high doses, may lead to severe poisoning, particularly in patients with psychiatric illnesses. Authorities should put forward a new policy for prescribing the drug as a treatment for alcohol dependence.  相似文献   
99.
The purpose of this article was to describe the serotype incidence and antibiotic susceptibility of Streptococcus pneumoniae strains isolated from adults and children with invasive disease (IPD) or acute otitis media (AOM) before introduction of the 13-valent pneumococcal vaccine. During 2009, 494 strains of S. pneumoniae isolated were collected. Complete serotyping by latex antisera and molecular methods was performed. The most frequent serotypes isolated from children with IPD were 1 (26.2%), 19A (25%) and 7F (14.3%). Serotype 19A was predominant (42.1%) in children ≤ 2 years, whereas serotype 1 was predominant (63.3%) after the age of 5. Serotype 19A was the most frequently isolated serotype from AOM (62.3%). In adults, serotypes responsible for IPD were 7F (19.4%), 19A (13.7%), 1 (8.4%) and 3 (7.5%). The serotype 19A was predominant in adults older than 65 years (19.1%). The emergence of serotype 12F was observed in adults. Between 2007 and 2009, the introduction of PCV-7 has resulted in a significant decrease of IPD caused by serotypes included in the vaccine, in children as well as in adults, confirming the herd effect. Serotype coverage of PCV-13 was 70% and 80.9% for adult and children’s IPD, respectively. PCV-13 will be more efficient in preventing invasive diseases among children and adults.  相似文献   
100.
Smad7 is a principal inhibitor of the TGFβ–Smad signalling pathway. We have investigated the functional significance of Smad7 in hepatocellular carcinoma (HCC). Smad7 knockout (KO) and wild‐type (WT) mice were injected with diethylnitrosamine (DEN) to induce HCC. The effects of Smad7 on cellular features were examined in HCC cells, using a Smad7 over‐expression or deletion approach. Signalling pathway components modulated by Smad7 in HCC were evaluated using luciferase reporter assay and co‐immunoprecipitation. Smad7 was down‐regulated in human HCCs compared with the adjacent normal tissues (p < 0.001). Smad7 KO mice were more susceptible to DEN‐induced HCC than WT mice (78% versus 22%, p < 0.05). HCCs from KO mice displayed a greater proliferation activity (p < 0.05) and a reduced apoptotic index compared with WT littermates (p < 0.05). Deletion of Smad7 promoted cell proliferation in primary cultured HCC cells. In addition, over‐expression of Smad7 in HCC cell lines markedly suppressed cell growth (p < 0.0001) and colony formation (p < 0.01). Cell cycle analysis revealed an increase in the G1 phase and a reduction in the S‐phase populations, accompanied by up‐regulation of p27Kip1 and down‐regulation of cyclin D1. Smad7 increased cell apoptosis (p < 0.01) by mediating an intrinsic [caspase‐9, caspase‐3 and poly(ADP‐ribose) polymerase] apoptotic pathway. Moreover, Smad7 inhibited NF‐κB signalling by interacting with TAB2, an upstream activator of NF‐κB, and inhibited TGFβ signalling by suppressing phosphorylation of Smad3. In conclusion, loss of Smad7 enhances susceptibility to HCC. Smad7 suppresses HCC cell growth by inhibiting proliferation and G1–S phase transition and inducing apoptosis through attenuation of NF‐κB and TGFβ signalling. Smad7 acts as a potential tumour suppressor in liver. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.  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