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   1302篇
  免费   78篇
  国内免费   3篇
耳鼻咽喉   11篇
儿科学   33篇
妇产科学   79篇
基础医学   152篇
口腔科学   59篇
临床医学   122篇
内科学   276篇
皮肤病学   11篇
神经病学   53篇
特种医学   30篇
外科学   227篇
综合类   20篇
预防医学   57篇
眼科学   27篇
药学   137篇
中国医学   6篇
肿瘤学   83篇
  2023年   34篇
  2022年   70篇
  2021年   93篇
  2020年   45篇
  2019年   62篇
  2018年   82篇
  2017年   55篇
  2016年   55篇
  2015年   38篇
  2014年   53篇
  2013年   65篇
  2012年   110篇
  2011年   119篇
  2010年   68篇
  2009年   55篇
  2008年   58篇
  2007年   64篇
  2006年   49篇
  2005年   65篇
  2004年   45篇
  2003年   35篇
  2002年   29篇
  2001年   2篇
  2000年   1篇
  1999年   5篇
  1998年   7篇
  1997年   4篇
  1996年   6篇
  1995年   2篇
  1994年   2篇
  1993年   3篇
  1992年   1篇
  1980年   1篇
排序方式: 共有1383条查询结果,搜索用时 15 毫秒
41.
There is an increasing demand for age estimations of living persons who are involved in civil and criminal procedures but lack a valid birth certificate indicating their date of birth. Several studies have recommended the application of magnetic resonance imaging (MRI) and assessment of the stage of epiphyseal fusion in age estimation. This study involved retrospective MRI analysis of 335 cases (217 males and 118 females) whose ages ranged from 8 to 28 years (yrs). We assessed the degree of ossification of the proximal tibial epiphysis depending on the classifications of Schmeling and Kellinghaus used for the main stages (I, II, III, IV & V) and substages (IIa, b, c & IIIa, b, c). Significant differences between males and females at stages IIIc, IV and V (p < 0.001) were observed. Additionally, the ossification of the proximal tibial epiphyses occurred earlier in females than in males (2–4 yrs). The mean of ages in stage IV was approximately 18.6 yrs. in females and 22.5 yrs. in males, meaning that stage IV can be used as a valuable forensic marker to determine whether the person in question has reached the age of 18 yrs. We concluded that the application of MRI in the assessment of the ossification status of the proximal tibial epiphysis could be helpful in age estimation for various forensic purposes.  相似文献   
42.
The aim of the present study was to determine the impact of CYP2C19*17 on the pharmacokinetics and pharmacodynamics of the active metabolite of clopidogrel and the pharmacokinetics of proguanil. Thus, we conducted an open‐label two‐phase cross‐over study in 31 healthy male volunteers (11 CYP2C19*1/*1, 11 CYP2C19*1/*17 and nine CYP2C19*17/*17). In Phase A, the pharmacokinetics of the derivatized active metabolite of clopidogrel (CAMD) and platelet function were determined after administration of a single oral dose of 600 mg clopidogrel (Plavix; Sanofi‐Avensis, Horsholm, Denmark). In Phase B, the pharmacokinetics of proguanil and its metabolites cycloguanil and 4‐chlorphenylbiguanide (4‐CPB) were determined in 29 of 31 subjects after a single oral dose of 200 mg proguanil given as the combination drug Malarone (GlaxoSmithKline Pharma, Brondby, Denmark). Significant correlations were found between the area under the time–concentration curve (AUC0–∞) of CAMD and both the absolute ADP‐induced P2Y12 receptor‐activated platelet aggregation (r = ?0.60, P = 0.0007) and the percentage inhibition of aggregation (r = 0.59, P = 0.0009). In addition, the CYP2C19*17/*17 and CYP2C19*1/*17 genotype groups had significantly higher percentage inhibition of platelet aggregation compared with the CYP2C19*1/*1 subjects (geometric mean percentage inhibition of 84%, 73% and 63%, respectively; P = 0.014). Neither the absolute ADP‐induced P2Y12 receptor‐activated platelet aggregation, exposure to CAMD nor the pharmacokinetic parameters of proguanil, cycloguanil and 4‐CPB exhibited any significant differences among the genotype groups. In conclusion, carriers of CYP2C19*17 exhibit higher percentage inhibition of platelet aggregation, but do not have significantly lower absolute P2Y12 receptor‐activated platelet aggregation or higher exposure to the active metabolite after a single oral administration of 600 mg clopidogrel.  相似文献   
43.
44.
There is an increasing demand on synthesizing pharmaceuticals and biomaterials that possess antimicrobial and/or antiviral activities. In this respective silver nanoparticles are known for their excellent antimicrobial activity. Nevertheless, their uncontrolled release in a biological medium can induce a cytotoxic effect. For this, we explored the use of nanolayered metal phosphates based on titanium and zirconium as materials that can be enriched with silver nanoparticles. Employing the hydrothermal route, crystalline α-phases of zirconium and titanium phosphates (α-ZrP, α-TiP) were synthesized and there after surface-enriched with silver nanoparticles. The structural assessment confirmed the stability of the structures and their sizes are in the nanoscale at least in one dimension. The cytocompatibility assays confirmed the biocompatibility of the pristine phases and the antimicrobial assay confirmed that both silver-enriched nanolayered structures maintain an antibacterial effect at reasonably low concentrations.  相似文献   
45.
BackgroundLife-threatening central venous catheter-related infections are primarily initiated by biofilm formation on the catheter surface. Antibiotic lock therapy is recommended for eradicating intraluminal biofilm. In the era of antibiotic resistance, antibiotics of natural origins provide an effective and cheap option for combating resistant strains. Garlic especially stole the spotlight because of its impressive antimicrobial effectiveness against such superbugs.AimIs to estimate the potential use of fresh garlic extract (FGE) as a lock agent against multi-drug resistant (MDR) bacteria.MethodsThe agar well diffusion and broth microdilution techniques were employed to test the antimicrobial activities of FGE against five MDR strains; E. coli, Pseudomonas aeruginosa (P. aeruginosa), Klebsiella pneumoniae (K. pneumoniae), Serratia marscens (S. marscens) and Methicillin-resistant Staphylococcus aureus (MRSA). Then the protective and therapeutic efficiencies of FGE against bacterial biofilms were in-vitro evaluated; at concentrations of 100, 75, 50 and 25%; in tissue culture plate (TCP) and on the polyurethane (PU) sheets using the crystal violet (CV) assay and colony-forming unit (CFU), respectively. Scanning electron microscopy (SEM) was also used to confirm eradication of biofilms on PU sheets. Finally, systemic and deep tissue infections by P. aeruginosa and MRSA were induced in mice that were then treated by FGE at either 100 or 200 mg/kg for seven days. Where the antibacterial activity was assessed by tissue and blood culturing at the end of the treatment period. Biochemical, hematological and histological parameters were also investigated.ResultsFGE exhibited potent in-vitro and in-vivo antibacterial and antibiofilm activities against MDR strains. It not only didn’t exhibit toxicological effects at the hematological and the histological levels but also provided protective effects as demonstrated by the significant drop in the biochemical parameters.ConclusionFGE has the potential to be used as a prophylactic and/or therapeutic lock agent against biofilm-associated infections caused by MDR bacteria.  相似文献   
46.
Refractory/relapsed acute leukemia has always been a challenging problem for hematologist. Over the past decade emphasis has been made in the development of regimens containing fludarabine, combined with cytosine arabinoside for the treatment of refractory/relapsed acute leukemias. The aim of this study is to evaluate the efficacy and toxicity of the combination of fludarabine, high dose cytarabine, and granulocyte colony stimulating factor in refractory relapsed cases of acute leukaemia, a prospective study is being conducted at the National Center of Hematology and hematology unit/Baghdad teaching hospital from July 2008 to July 2010. Twenty Patients with refractory/relapsed acute leukemia were treated with fludarabine 30 mg/m2 and cytosine arabinoside (Ara-C) 2 g/m2 for 5 days, and granulocyte colony stimulating factor G-CSF 300 µg/day from day 0 till neutrophil recovery (ANC > 1.0 × 109/L). Response was evaluated by bone marrow examination on day 30 post chemotherapy. Patients included were refractory acute lymphoblastic leukemia (ALL) (five patients), relapsed ALL (four patients), refractory acute myeloid leukemia (AML) (eight patients), relapsed AML (three patients). Complete remission (CR) was achieved in nine (45 %) patients, while three (15 %) patients got partial remission. Three (15 %) patients died because of post chemotherapy complications and five (25 %) patient failed to achieve remission. Major complications encountered were: anemia, fever, bleeding, mucositis and bacterial infections. FLAG protocol is well tolerated and effective regimen in relapsed/refractory acute leukemias. The toxicity is acceptable, enabling most patients to receive further treatment, including transplantation procedures.  相似文献   
47.
Metabolic Brain Disease - Diabetes mellitus is an increasing metabolic disease worldwide associated with central nervous system disorders. Coffee is a widely consumed beverage that enriched with...  相似文献   
48.
49.
50.

Background

Burn injuries to the chest area may end up with severe breast deformity and asymmetry. They are frequently complex and unique to each case, affecting parenchymal development, breast implantation on chest wall, nipple areola complex position, infra-mammary fold definition, and skin envelope. Furthermore, contractures affecting adjacent territories may occur and add to the deformity. Surgical correction should address all the deformity components. Thus, a structured reconstructive plan that recruits different mammaplasty techniques and deals with adjacent territories is needed. This work presents different strategies used in treating severe post-burn breast deformities. Elaborate analyses of the deformities, surgical techniques, and outcomes are presented and a structured reconstructive plan is proposed.

Methods

Sixteen deformed breasts in 11 patients (mean age, 22 years) were managed. The techniques used included a variety of mastopexy techniques, prosthesis-based endoscopic breast reconstruction, and autologous breast augmentation with fat grafting or local flaps in some hypoplastic cases. Ancillary procedures to the neck, axilla, and abdomen were carried out to release the breast when tethered by their contractures.

Results

Considerable improvement and reasonable symmetry were achieved in most cases. All patients were satisfied with the results, tolerated the need for multiple procedures, and accepted residual minor asymmetries.

Conclusions

A post-burn breast deformity has a complex nature that may be addressed on multiple stages with different techniques of mastopexy, augmentation, and reconstruction. Ancillary procedures to a contracted adjacent territory may be needed to release the breast if tethered. Adopting a structured reconstructive plan may help obtain reproducible constant results. Level of Evidence: Level IV, therapeutic study.  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