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   422篇
  免费   81篇
  国内免费   9篇
耳鼻咽喉   4篇
儿科学   12篇
妇产科学   4篇
基础医学   42篇
口腔科学   6篇
临床医学   77篇
内科学   88篇
皮肤病学   18篇
神经病学   26篇
特种医学   84篇
外科学   36篇
综合类   6篇
现状与发展   1篇
预防医学   21篇
眼科学   2篇
药学   25篇
肿瘤学   60篇
  2024年   4篇
  2023年   24篇
  2022年   5篇
  2021年   5篇
  2020年   16篇
  2019年   6篇
  2018年   16篇
  2017年   21篇
  2016年   20篇
  2015年   11篇
  2014年   23篇
  2013年   17篇
  2012年   11篇
  2011年   8篇
  2010年   12篇
  2009年   13篇
  2008年   5篇
  2007年   12篇
  2006年   4篇
  2005年   11篇
  2004年   6篇
  2003年   6篇
  2002年   4篇
  2001年   9篇
  2000年   5篇
  1999年   8篇
  1998年   18篇
  1997年   7篇
  1996年   5篇
  1995年   9篇
  1994年   20篇
  1993年   12篇
  1992年   11篇
  1991年   6篇
  1990年   6篇
  1989年   15篇
  1988年   12篇
  1987年   13篇
  1986年   11篇
  1985年   10篇
  1984年   12篇
  1983年   10篇
  1982年   7篇
  1981年   8篇
  1980年   9篇
  1979年   3篇
  1978年   3篇
  1977年   3篇
  1976年   3篇
  1975年   4篇
排序方式: 共有512条查询结果,搜索用时 15 毫秒
101.
Malignant melanoma (MM) is a highly aggressive neoplasm with a growing worldwide incidence. It is not uncommon that the disease is already metastatic at the time of the first diagnosis. Regional lymph nodes and skin are the first and most common metastatic sites, followed by distant visceral sites (lungs, liver, and central nervous system) and bone. In this clinical setting, fine-needle aspiration (FNA) often represents the first diagnostic approach. FNA is a useful tool to obtain a rapid and accurate diagnosis, in conjunction with ancillary techniques and molecular analysis, as recommended by recent guidelines. The aim of this review was to describe the cytomorphology, immunocytochemical tools, and molecular tools used for the diagnosis of MM metastases on FNA.  相似文献   
102.
Background and objective: Most antidiabetic agents target only one of several underlying causes of diabetes. The complementary actions of the glinides and the biguanides may give optimal glycemic control in patients with type 2 diabetes mellitus. The aim of the present study was to compare the effects of nateglinide plus metformin with glibenclamide plus metformin on glucose and lipid metabolism, and haemodynamic parameters in patients with type 2 diabetes mellitus. Methods: We enrolled 248 type 2 diabetic patients. Patients were randomly assigned to receive nateglinide (n = 124) or glibenclamide (n = 124), after 6 months of run‐in, in which we titrated nateglinide (starting dose 180 mg/day), glibenclamide (starting dose 7·5 mg/day), and metformin (starting dose 1500 mg/day). The final doses were (mean ± standard deviation), 300 ± 60, 12·5 ± 2·5, and 2500 ± 500 mg/day, respectively. We followed these patients for 1 year after titration. We assessed body mass index (BMI), fasting (FPG) and post‐prandial (PPG) plasma glucose, glycosylated haemoglobin (HbA1c), fasting (FPI) and post‐prandial (PPI) plasma insulin, homeostasis model assessment (HOMA) index, and lipid profile [total cholesterol (TC), low density lipoprotein‐cholesterol (LDL‐C), high density lipoprotein‐cholesterol (HDL‐C), triglycerides (Tg), apolipoprotein A‐I (Apo A‐I), and apolipoprotein B (Apo B)], systolic blood pressure (SBP), and diastolic blood pressure (DBP). All variables were evaluated at baseline and after 3 and 6 months in the run‐in period, and at baseline, and after 3, 6, 9 and 12 months for both treatment groups. Results and discussion: Body mass index did not show any significant change during the study. We observed a significant improvement from baseline to 1 year on HbA1c (P < 0·01 vs. baseline and vs. glibenclamide group, respectively), FPG (P < 0·01 vs. baseline), PPG (P < 0·01 vs. baseline), and on HOMA index (P < 0·05 vs. baseline) in the nateglinide group. In the glibenclamide group, we found significant changes in HbA1c (P < 0·05 vs. baseline), FPG (P < 0·01 vs. baseline), PPG (P < 0·05 vs. baseline), and HOMA index (P < 0·05 vs. baseline). No significant change was observed in TC, LDL‐C, HDL‐C, Tg, Apo A‐I, Apo B, SBP, DBP and HR in either group after 3, 6, 9 and 12 months. These effects of nateglinide and glibenclamide on insulin‐resistance parameters are in agreement with previous reports. Contrarily to previous reports, we did not observe any significant BP change in patients treated with glibenclamide. Although both nateglinide and glibenclamide attenuated PPG and HOMA index, they did not have significant effects on lipid metabolism, as already shown in subjects with type 2 diabetes and good glycemic control. Conclusion: Nateglinide improved glycemic control better than glibenclamide in combination with metformin.  相似文献   
103.

Background

The identification of pathological markers of breast cancer for either diagnosis, treatment response or for survival is of critical importance.

Methods

Serum protein profiling using 2-DE separations coupled to matrix-assisted laser desorption ionization mass spectrometry has been used to explore protein alterations in patients with infiltrating ductal breast carcinomas (IDCA). Sera from 39 breast cancer patients and 40 healthy controls were selected for screening study using 2-DE combined with MS. The protein expression patterns obtained after the depletion of high abundance proteins was determined by coomassie blue G-250 stain after 2-DE electrophoresis.

Results

Six proteins that expressed differentially in the IDCA group were found. The expression levels of four isoforms corresponding to haptoglobin precursor and two isoforms of α1-antitrypsin precursor (α1-AT) were upregulated in sera from breast cancer patients. There was an increased expression of both proteins in the sera of patients with various tumor stages (I, II, III) in comparison to healthy women. Applying immunohistochemistry, we further validated α1-AT immunoreactivity in 51 formalin-fixed paraffin-embedded sections of breast tumors. Enhanced expression of α1-AT like activity has been found in IDCA breast tumors, as well as, in different histological types of breast cancer. No significant association has been found with lymph node occurrence, while in high tumor categories a tendency to an increased expression of α1-AT has been found, thereby suggesting a possible role of this protein in tumor growth.

Conclusions

These proteins may constitute new and useful markers of breast cancer that offer a clue to a better understanding of inflammatory pathways and carcinogenesis events linked to breast cancer progression.  相似文献   
104.
Data are reported from a larger study of perceptions of locus of control and value of pressure ulcer prevention to show the position of orthopaedic nurse control beliefs, their departmental knowledge level, and their value of pressure ulcer prevention relative to that of staff in other specialties. The survey population consisted of trained and assistant nursing staff in both hospital and community settings of a rural Health Service Trust. Overall results showed that key personnel, such as sisters, were significantly associated with prevalence, in that the more they believed they controlled pressure sore prevention, rather than the patient, the higher the prevalence. This has been explained using locus of control typology. The more it was thought that fate controls pressure sore prevention, the lower the departmental prevalence. Further, beliefs about specific conditions (e.g. pressure ulcer prevention) may be less important than generalized beliefs about control in terms of reducing prevalence.It is suggested that the study is replicated and refined, and that the value of pressure sore prevention needs raising. Certain types of attitudes amongst staff may be unhelpful in a broader range of conditions and outcomes. There may be a need to change control expectations of groups of personnel in order to protect patients.  相似文献   
105.
Zusammenfassung Unter Berücksichtigung eines eigenen Falles von isolierter Subluxation des Metacarpus 5 werden die bisher in dem Schrifttum beobachteten F?lle von Luxatio carpometacarpea cr?rtert. Mit Darlegung der Anatomie der Carpometacarpalgelenke werden die verschiedenen hierher geh?renden Luxationsformen besonders nach ihrem Entstehungsmechanismus besprochen. In der eigenen Beobachtung wird die Spielart der Subluxation als „seitliche“ erl?utert.  相似文献   
106.
107.
108.
109.
When lymphocytes are stimulated with mitogens or antigens they are enhanced via a cascade of lymphokines to produce interferon-y (IFN-y). IFN-y augments the H2O2secretion of human monocytes which indirectly can be measured by chemiluminescence. We tested prednisone, 16-methylen. prednisolone and ACTH for their effect to inhibit the Con-A induced stimulation of the chemiluminescence-activity. All three hormones inhibited significantly the stimulation: prednisone up to 52.5 % (concentration = 150 m;g/ml, p=0.000005), 16-methylen-prednisolone up to 22.5 % (concentration = 2.5 & m g/ml, p=0.006) and ACTH up to 33 % (concentration = 10 m g/ml, p=0.0036).  相似文献   
110.
HLA-A2 heavy chain and beta 2-microglobulin were expressed in Escherichia coli, and refolded in the presence of peptides derived from HIV-1 RT and gag proteins. When recombinant HLA-A2 molecules were attached to cells lacking HLA-A2, the cells became susceptible to lysis by HLA-A2-restricted cytotoxic T lymphocyte (CTL) clones specific for peptides derived from RT and gag proteins. Limiting dilution analyses of peripheral blood mononuclear cells from HIV-1-infected individuals showed that the recombinant HLA-A2 peptide complexes covalently immobilized on microspheres stimulated the development of HLA-A2 peptide-specific CTL. Preformed HLA-peptide complexes may provide an alternative to immunization procedures that depend upon intracellular processing of antigen to elicit T cell responses.   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