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   549篇
  免费   39篇
儿科学   14篇
妇产科学   16篇
基础医学   77篇
口腔科学   4篇
临床医学   62篇
内科学   113篇
皮肤病学   6篇
神经病学   33篇
特种医学   28篇
外科学   61篇
综合类   11篇
预防医学   70篇
眼科学   10篇
药学   32篇
肿瘤学   51篇
  2023年   4篇
  2022年   5篇
  2021年   22篇
  2020年   7篇
  2019年   15篇
  2018年   23篇
  2017年   16篇
  2016年   4篇
  2015年   16篇
  2014年   18篇
  2013年   18篇
  2012年   31篇
  2011年   43篇
  2010年   19篇
  2009年   22篇
  2008年   34篇
  2007年   37篇
  2006年   21篇
  2005年   32篇
  2004年   26篇
  2003年   22篇
  2002年   23篇
  2001年   12篇
  2000年   5篇
  1999年   10篇
  1998年   5篇
  1997年   4篇
  1996年   7篇
  1994年   5篇
  1992年   6篇
  1991年   3篇
  1990年   5篇
  1989年   3篇
  1987年   2篇
  1986年   2篇
  1983年   2篇
  1979年   4篇
  1978年   7篇
  1977年   5篇
  1976年   2篇
  1974年   7篇
  1973年   5篇
  1972年   5篇
  1970年   2篇
  1969年   4篇
  1968年   3篇
  1966年   2篇
  1965年   4篇
  1936年   1篇
  1928年   1篇
排序方式: 共有588条查询结果,搜索用时 15 毫秒
1.
2.
We analysed a group of 390 patients, diagnosed with chronic lymphocytic leukaemia (CLL). Cases were subclassified as morphologically typical and atypical CLL according to the criteria of the FAB proposal. Typical CLL cases were mostly diagnosed at a low-risk stage (Binet A/Rai 0), required no immediate treatment and expected a long survival; atypical CLL cases mostly presented at a more advanced risk stage (Binet B/Rai I–II), usually required immediate treatment and their survival was shorter. Moreover, clinical staging was of prognostic significance in typical but not in atypical cases.   In typical CLL, del(11q) was the most common chromosomal abnormality (21%) whereas in atypical CLL trisomy 12 was found in about 65% of the cases documented with an abnormal karyotype. Although chromosomal abnormalities were associated with a poor survival in typical CLL, they are of no prognostic significance in atypical CLL.   Based on these data, we conclude that subtyping CLL by morphology enables the identification of two groups of cases, each characterized by a specific clinical presentation, different cytogenetic abnormalities and prognostic parameters. We speculate that these two groups may represent two related, but different, diseases with different prognostic parameters and a different survival.  相似文献   
3.
In a single outbreak on the East coast of Madagascar, more than 500 people, 98 of whom died, were poisoned by the flesh of a shark, Carcharhinus amboinensis. From clinical symptoms it can be concluded that this poisoning is due to ciguatera toxins. It is the first case of a severe outbreak caused by a shark, and it is the first case with a mortality rate of 20%.  相似文献   
4.
5.
BACKGROUND: After hematopoietic cell transplantation (HCT), hepatitis due to hepatitis B virus (HBV) rarely occurred beyond the initial 12 months after transplantation. OBJECTIVES: We investigated the cause of "late" hepatitis due to HBV infection in two recipients after allogeneic HCT. STUDY DESIGN: Two male patients with acute myeloid leukemia and light chain myeloma, respectively, developed HBV-related hepatitis more than 2 years after HCT. All serum samples collected from the recipients, donors and their respective spouses were tested for HBV DNA by nested PCR, and if positive further quantified by Digene Hybrid Capture assay II. The HBV genotype was determined by PCR and sequencing. RESULTS: Genotypic analysis suggested that the cause of "late" hepatitis was due to acute HBV infection transmitted from their respective spouse. CONCLUSION: Our findings suggested that sexual precautions should be taken in these patients after HCT. Alternatively, or even additionally, active vaccination should be delivered to these patients once they have lost their HBV immunity.  相似文献   
6.
HLA Antigens in 16 Families with Xeroderma Pigmentosum   总被引:1,自引:0,他引:1  
Xeroderma pigmentosum is an autosomal recessive disease. HLA-A and -B typing was performed on peripheral blood lymphocytes and platelets. Sixteen Tunisian families were typed with 37 patients and 108 relatives. Genetic transmission of the disease and of the HLA system seemed to be independent in this study. Comparison of HLA gene frequencies between (unrelated) parents of patients and a control population showed no difference, proving that there is no clear association in populations between deleterious XP genes and a particular HLA gene. However, an excess of identical HLA among pairs of diseased siblings would suggest that the disease is polymorphic and a form of the XP could be linked to HLA.  相似文献   
7.
(1) Background: vitamin E is often supplemented in the form of tocopherol acetate, but it has poor bioavailability and can fail to correct blood tocopherol concentrations in some patients with severe cholestasis. In this context, α-tocopheryl polyethylene glycol succinate 1000 (TPGS) has been of value, but very little is known about the mechanisms of its absorption. The aim of our work was to evaluate the mechanisms of absorption/secretion of TPGS compared to tocopherol acetate (TAC) and α-tocopherol by human enterocyte-like Caco-2 TC7 cells. (2) Methods: two weeks post-confluence Caco-2 cells were incubated with tocopherol- or TAC- or TPGS-rich mixed micelles up to 24 h and, following lipid extraction, TAC and tocopherol amounts were measured by high performance liquid chromatography (HPLC) in apical, cellular, and basolateral compartments. (3) Results: at equivalent concentrations of tocopherol in the apical side, the amounts of tocopherol secreted at the basolateral pole of Caco-2 cells are (i) significantly greater when the tocopherol is in the free form in the micelles; (ii) intermediate when it is in the TAC form in the micelles (p < 0.001); and (iii) significantly lower with the TPGS form (p < 0.0001). Interestingly, our results show, for the first time, that Caco-2 cells secrete one or more esterified forms of the vitamin contained in TPGS at the basolateral side.  相似文献   
8.
Macro and micronutrient deficiencies pose serious health challenges globally, with the largest impact in developing regions such as subSaharan Africa (SSA), Latin America and South Asia. Maize is a good source of calories but contains low concentrations of essential nutrients. Major limiting nutrients in maize-based diets are essential amino acids such as lysine and tryptophan, and micronutrients such as vitamin A, zinc (Zn) and iron (Fe). Responding to these challenges, separate maize biofortification programs have been designed worldwide, resulting in several cultivars with high levels of provitamin A, lysine, tryptophan, Zn and Fe being commercialized. This strategy of developing single-nutrient biofortified cultivars does not address the nutrient deficiency challenges in SSA in an integrated manner. Hence, development of maize with multinutritional attributes can be a sustainable and cost-effective strategy for addressing the problem of nutrient deficiencies in SSA. This review provides a synopsis of the health challenges associated with Zn, provitamin A and tryptophan deficiencies and link these to vulnerable societies; a synthesis of past and present intervention measures for addressing nutrient deficiencies in SSA; and a discussion on the possibility of developing maize with multinutritional quality attributes, but also with adaptation to stress conditions in SSA.  相似文献   
9.
Interferons and interleukin-10 are involved in key aspects of the host defence mechanisms. Human chromosome 21 harbors the interferon/interleukin-10 receptor gene cluster linked to the GART gene. This cluster includes both components of the interferon alpha/beta-receptor (IFNAR1 and IFNAR2) and the second components of the interferon gamma-receptor (IFNGR2) and of the IL-10 receptor (IL10R2). We report here the complete gene content of this GART-cytokine receptor gene cluster and the use of comparative genomic analysis to identify chicken IFNAR1, IFNAR2, and IL10R2. We show that the large-scale structure of this locus is conserved in human and chicken but not in the pufferfish Fugu rubripes. This establishes that the receptor components of these host defense mechanisms were fixed in an ancestor of the amniotes. The extraordinary diversification of the interferon ligand family during the evolution of birds and mammals has therefore occurred in the context of a fixed receptor structure.  相似文献   
10.
Conservative treatment for postintubation tracheobronchial rupture   总被引:10,自引:0,他引:10  
BACKGROUND: Postintubation tracheobronchial rupture is usually responsible for unstable intraoperative or postoperative conditions, and its management is discussed. We insist on conservative treatment as a viable alternative after late diagnosis of postintubation tracheobronchial rupture. METHODS: We conducted a retrospective study including 14 consecutive patients treated between April 1981 and July 1998. RESULTS: Twelve tracheobronchial ruptures occurred after intubation for general surgery and two after thoracic surgery. In all cases, the tear consisted of a linear laceration of the posterior membranous wall of the tracheobronchial tree ranging from 2 to 6 cm. One death occurred in a very weak patient unfit to undergo a redo operation for surgical repair. Seven patients were treated conservatively and cured without sequelae. Six patients underwent surgical repair, of whom 2 were diagnosed and repaired intraoperatively. CONCLUSIONS: Aggressive surgical repair is not always mandatory after delayed diagnosis of iatrogenic tracheobronchial rupture. Conservative treatment must often be considered, except after lung resection.  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