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   424篇
  免费   29篇
  国内免费   4篇
耳鼻咽喉   5篇
儿科学   15篇
妇产科学   13篇
基础医学   50篇
口腔科学   9篇
临床医学   38篇
内科学   94篇
皮肤病学   10篇
神经病学   43篇
特种医学   10篇
外科学   96篇
综合类   7篇
预防医学   7篇
眼科学   7篇
药学   37篇
中国医学   1篇
肿瘤学   15篇
  2024年   1篇
  2023年   1篇
  2022年   6篇
  2021年   7篇
  2020年   9篇
  2019年   9篇
  2018年   8篇
  2017年   3篇
  2016年   12篇
  2015年   21篇
  2014年   17篇
  2013年   23篇
  2012年   28篇
  2011年   35篇
  2010年   21篇
  2009年   12篇
  2008年   37篇
  2007年   44篇
  2006年   41篇
  2005年   38篇
  2004年   34篇
  2003年   15篇
  2002年   11篇
  2001年   8篇
  2000年   1篇
  1999年   3篇
  1998年   2篇
  1995年   2篇
  1992年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1983年   2篇
  1981年   1篇
  1974年   1篇
排序方式: 共有457条查询结果,搜索用时 31 毫秒
21.
BACKGROUND: Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is a novel tumour marker that has been described in various kinds of cancer. The majority of observations include immunohistochemical studies; however, there are not enough data about the utility of this antigen as a serum tumour marker and its tumour specificity. AIM: To measure the serum levels of RCAS1 in patients with gastrointestinal (GI) tract cancers and compare them with other GI tract tumour markers. PATIENTS AND METHODS: Sera collected from patients with GI cancers (14 esophagus, 32 gastric and 36 colon) and from healthy volunteers (30 individuals) were analyzed for RCAS1 and compared with carcinoembryonic antigen (CEA) and cancer antigen 19-9. The relationship between serum RCAS1, tumour stage and tumour grade was also evaluated. RESULTS: Mean serum RCAS1 level was higher in patients with GI tract cancers compared with the control group (P=0.001). Among GI tract cancers, RCAS1 had lowest and highest sensitivity for esophagus and colon cancer diagnosis, respectively. Serum RCAS1 had a higher sensitivity for malignancy, except in the colon, and lower specificity in all groups compared with CEA. In comparison with cancer antigen 19-9, serum RCAS1 was more sensitive but less specific for all GI cancer groups. Mean serum RCAS1 levels were not statistically significant among histopathological tumour types (P>0.05). Although serum RCAS1 levels were significantly higher in cases with lymph node involvement compared with lymph node-negative cases (P=0.009), there was no difference between cases with and without serosal involvement, vascular invasion and distant metastasis; no correlation was found between tumour size and RCAS1 levels. CONCLUSIONS: RCAS1 may be used and combined with CEA as a tumour marker in GI tract cancers.  相似文献   
22.
We sought to investigate whether application of topical tetracycline has a limiting effect on seroma formation in patients undergoing hernia repair using a polypropylene mesh. This study was conducted in 96 patients undergoing an elective groin hernia repair. Patients were randomized and divided into 2 groups. After the graft was placed, and before external oblique muscle aponeurosis was closed, 5 mL tetracycline was administered on the graft in the tetracycline group (tetra group, n = 50), and 5 mL isotonic saline was administered in the control group (n = 46) without putting in a drain. Seroma checks via surface ultrasonography were done. Seroma amounts measured on the first day were significantly higher in the tetra group (P = 0.04). There were no significant differences regarding seroma measurements on the seventh day or in the first and second months. Topical tetracycline application has no limiting effect on seroma formation after a groin hernia operation.Key words: Lichtenstein technique, Polypropylene mesh, Topical tetracycline, Seroma, UltrasonographyHernia operations are among the most frequently performed surgical operations. Graft use to repair the defect is commonplace because graft use decreases recurrence rate, and defect closure in large abdominal hernias is easier with a mesh.1 The most commonly used and least expensive mesh is the polypropylene mesh. This mesh causes a foreign-body reaction where it is placed, which leads to seroma formation.2 Repeat aspirations of seromas cause infection, and recurrence is seen on follow-up, especially in large hernias.2 While drain use is not recommended in groin hernias, drain use in other abdominal-wall hernias is left to the physician''s discretion. The biggest problem with drain use is transport of the infection by an ascending route.3Tetracycline is an antibiotic, the solution form of which is topically used for pleurodesis in chest surgery.4 Some researchers also report successful topical use of its solution in seroma treatment, taking advantage of its sclerosing effect in cases with breast carcinoma.5,6 Tetracycline has demonstrated increased growth factor–like activity in mesothelial cells exposed to tetracycline leading to fibroblast proliferation.7 This study sought to investigate whether tetracycline has a reducing effect on seroma development in cases undergoing elective groin hernia repair using a polypropylene mesh.  相似文献   
23.
Because vaccination is an effective means to protect humans from influenza viruses, extensive efforts have been made to develop not only new vaccines, but also for new adjuvants to enhance the efficacy of existing inactivated vaccines. Here, we examined the adjuvanticity of synthetic hemozoin, a synthetic version of the malarial by-product hemozoin, on the vaccine efficacy of inactivated whole influenza viruses in a mouse model. We found that mice immunized twice with hemozoin-adjuvanted inactivated A/California/04/2009 (H1N1pdm09) or A/Vietnam/1203/2004 (H5N1) virus elicited higher virus-specific antibody responses than did mice immunized with non-adjuvanted counterparts. Furthermore, mice immunized with hemozoin-adjuvanted inactivated viruses were better protected from lethal challenge with influenza viruses than were mice immunized with non-adjuvanted inactivated vaccines. Our results show that hemozoin improves the immunogenicity of inactivated influenza viruses, and is thus a promising adjuvant for inactivated whole virion influenza vaccines.  相似文献   
24.
Genetic ataxias are associated with mutations in hundreds of genes with high phenotypic overlap complicating the clinical diagnosis. Whole‐exome sequencing (WES) has increased the overall diagnostic rate considerably. However, the upper limit of this method remains ill‐defined, hindering efforts to address the remaining diagnostic gap. To further assess the role of rare coding variation in ataxic disorders, we reanalyzed our previously published exome cohort of 76 predominantly adult and sporadic‐onset patients, expanded the total number of cases to 260, and introduced analyses for copy number variation and repeat expansion in a representative subset. For new cases (n = 184), our resulting clinically relevant detection rate remained stable at 47% with 24% classified as pathogenic. Reanalysis of the previously sequenced 76 patients modestly improved the pathogenic rate by 7%. For the combined cohort (n = 260), the total observed clinical detection rate was 52% with 25% classified as pathogenic. Published studies of similar neurological phenotypes report comparable rates. This consistency across multiple cohorts suggests that, despite continued technical and analytical advancements, an approximately 50% diagnostic rate marks a relative ceiling for current WES‐based methods and a more comprehensive genome‐wide assessment is needed to identify the missing causative genetic etiologies for cerebellar ataxia and related neurodegenerative diseases.  相似文献   
25.
White‐Sutton syndrome (WHSUS) is a recently‐identified genetic disorder resulting from de novo heterozygous pathogenic variants in POGZ. Thus far, over 50 individuals have been reported worldwide, however phenotypic characterization and data regarding the natural history are still incomplete. Here we report the clinical features of 22 individuals with 21 unique loss of function POGZ variants. We observed a broad spectrum of intellectual disability and/or developmental delay with or without autism, and speech delay in all individuals. Other common problems included ocular abnormalities, hearing loss and gait abnormalities. A validated sleep disordered breathing questionnaire identified symptoms of obstructive sleep apnea in 4/12 (33%) individuals. A higher‐than‐expected proportion of cases also had gastrointestinal phenotypes, both functional and anatomical, as well as genitourinary anomalies. In line with previous publications, we observed an increased body mass index (BMI) z‐score compared to the general population (mean 0.59, median 0.9; p 0.0253). Common facial features included microcephaly, broad forehead, midface hypoplasia, triangular mouth, broad nasal root and flat nasal bridge. Analysis of the Baylor Genetics clinical laboratory database revealed that POGZ variants were implicated in approximately 0.14% of cases who underwent clinical exome sequencing for neurological indications with or without involvement of other body systems. This study describes a greater allelic series and expands the phenotypic spectrum of this new syndromic form of intellectual disability and autism.  相似文献   
26.
27.
The high capacity of liver regeneration after partial hepatectomy (PH) is well known. This study investigated the role of the antioxidant defense system in regeneration among Wistar-albino male rats subjected to 70% partial hepatectomy after a pretreatment period of 2 weeks with eicosapentanoic acid (EPA) rich fish oil (FO), first pressed virgin olive oil (OO), or vitamin E. The control group of 10 rats underwent PH only. On postoperative day 3, all rats were humanely killed. Liver sections of animals treated with FO or vitamin E showed significant increases in regeneration within both liver parenchyma and cut surface compared with the control group (P < .05). Liver sections of OO displayed an insignificant increase in liver regeneration (P > .05), with less increase in parenchyma than of the cut surface. The enhancement of the liver parenchymal regeneration in the FO group was significantly greater than that of the vitamin E group. Concerning liver function tests (LFT), there was no significant difference among the groups. When the treatment groups were compared to the control group glutathione (GSH) levels were increased and content of malondialdehyde (MDA), nitric oxide (NO), and superoxide dismutase (SOD) were decreased. Based on these results, we concluded that after 70% PH in rats, the liver parenchyma and cut surface regeneration were greatest with FO and least with OO treatment. Both FO and vitamin E served to improve the antioxidant defense system more than OO treatment.  相似文献   
28.
29.
Bacillus anthracis infection can lead to necrosis in tissues and may manifest as a fatal disease in human beings. The authors present a patient with a large area of skin necrosis on the dorsum of the hand that was reconstructed with a reverse flow-through radial forearm flap, and they discuss the relevant literature. To the authors' knowledge, this is the first published report of such extensive necrosis resulting from anthrax limited to the extensor retinaculum of the hand.  相似文献   
30.
The levels of some organochlorine pesticides (OCP)s (hexachlorobenzene, HCB, -hexachlorocyclohexane, -HCH, -HCH, -HCH, heptachlorepoxide, HE, bis (4-chlorophenyl)-1,1-dichloroethene, p.pDDE, bis (4-chlorophenyl)-1,1,1-trichloroethane, p.p DDT and total DDT (-DDT) and antioxidant enzyme activities namely Cu, Zn superoxide dismutase (SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px), total glutathione peroxidase (T-GSH-Px), selenium independent glutathione peroxidase (GSH-Px II), glutathione reductase (GRd), level of reduced glutathione (GSH) and lipid peroxidation (LP), glutathione S-transferase (GST) activity toward several substrates including 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), ethacrynic acid (EAA), 1,2-epoxy-3-(p-nitrophenoxy)-propane (ENPP) were measured in tumor and surrounding tumor free tissues of 24 female breast cancer patients and was evaluated whether there exist any association between the levels of OCPs and antioxidants. The mean levels of GSH, -BHC, -BHC and HE, and activities of SOD, Se-GSH-Px, T-GSH-Px, GSH-Px II,GRd, GST CDNB, and GST DCNB were significantly higher in tumors than in controls. In tumors, significant correlations were noted between: SOD and -BHC; Se-GSH-Px and -BHC; T-GSH-Px and -BHC; GSH-Px II and -BHC, -BHC; GSH and -BHC, -BHC, HE; GRd and -BHC; CDNB GST and -BHC, -BHC. These results show that free-radical mediated oxidative stress is, at least partly, associated with some of these OCP residues in human breast tumors.  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