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   164篇
  免费   3篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   4篇
妇产科学   2篇
基础医学   14篇
口腔科学   2篇
临床医学   13篇
内科学   48篇
皮肤病学   2篇
神经病学   1篇
特种医学   12篇
外国民族医学   2篇
外科学   40篇
综合类   9篇
预防医学   2篇
药学   11篇
肿瘤学   4篇
  2021年   7篇
  2020年   2篇
  2019年   1篇
  2018年   4篇
  2017年   3篇
  2015年   4篇
  2014年   15篇
  2013年   10篇
  2012年   11篇
  2011年   11篇
  2010年   9篇
  2009年   6篇
  2008年   4篇
  2007年   5篇
  2006年   6篇
  2005年   3篇
  2004年   7篇
  2003年   5篇
  2002年   1篇
  2001年   1篇
  2000年   5篇
  1999年   3篇
  1998年   4篇
  1997年   3篇
  1996年   8篇
  1995年   3篇
  1994年   1篇
  1993年   3篇
  1990年   1篇
  1989年   3篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1984年   3篇
  1983年   1篇
  1982年   3篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1974年   1篇
  1973年   1篇
排序方式: 共有168条查询结果,搜索用时 15 毫秒
121.
122.
BACKGROUND: Plasminogen activator inhibitor type 1 (PAI-1) is the main inhibitor of the fibrinolytic system and contributes to an increased risk of atherothrombosis in insulin-resistant obese patients. In adipose tissue, we have shown that PAI-1 is synthesized mainly in the visceral stromal compartment and is positively regulated by glucocorticoids. We have demonstrated that adipose tissue expression of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD-1), an enzyme that catalyzes the conversion of inactive cortisone to active cortisol, is exaggerated in obese patients. OBJECTIVES: We hypothesized that increased action of 11beta-HSD-1 in adipose tissue of obese subjects may contribute to PAI-1 overproduction. PATIENTS AND METHODS: Using in situ hybridization, we studied the expression of the mRNAs coding for PAI-1 and 11beta-HSD-1 in the stromal compartment of visceral adipose tissue obtained from obese women. The regulation of PAI-1 secretion from in vitro incubated tissue explants was also investigated. RESULTS: Regression analysis showed a significant positive linear relationship between PAI-1 and 11beta-HSD-1 mRNAs expression. In vitro incubation of adipose tissue explants demonstrated that cortisone stimulated PAI-1 gene expression and secretion, and that these effects were inhibited by co-incubation with the 11beta-HSD inhibitor, glycyrrhetinic acid. CONCLUSIONS: Our data demonstrate that 11beta-HSD-1-driven cortisone reactivation regulates adipose PAI-1 synthesis and secretion. They suggest that the increased PAI-1 synthesis and secretion observed in obese patients can be also related, at least in part, to an increased local conversion of cortisone to cortisol. Therefore, local cortisol metabolism in adipose tissue may be involved in increasing the risk of cardiovascular disease in obese subjects.  相似文献   
123.
Peerschke  EI; Galanakis  DK 《Blood》1987,69(3):950-952
The alpha chain 572-574 Arg-Gly-Asp sequence of fibrinogen appears to play only a minor role in platelet aggregation based on the ability of fibrinogen preparations lacking alpha chain carboxyterminal segments to support platelet aggregation, but synthetic Arg-Gly-Asp-Ser (RGDS) peptides are capable of inhibiting platelet aggregation and fibrinogen binding. The present study thus examined the ability of RGDS peptides to inhibit platelet interactions with a plasmic degradation product of fibrinogen (8D-50) that resembles an intermediate fragment X. Gel- filtered, human blood platelets suspended in 0.01 mol/L HEPES-buffered modified Tyrode's solution, pH 7.5, were stimulated with 20 mumol/L adenosine diphosphate and the binding of 125I-labeled 8D-50 or intact fibrinogen (0.01 to 0.6 mg/mL) assessed in the presence of 0 to 117 mumol/L RGDS. The data revealed that RGDS decreased the apparent affinity of 8D-50 and intact fibrinogen for platelets but did not affect the maximum number of binding sites. RGDS thus appears to be a competitive inhibitor not only of intact fibrinogen (Ki = 12 +/- 2 mumol/L) but also of 8D-50 (Ki = 15 +/- 3 mumol/L) (mean +/- SD, n = 3).  相似文献   
124.
Haidaris  PJ; Peerschke  EI; Marder  VJ; Francis  CW 《Blood》1989,74(7):2437-2444
The gamma chain of human plasma fibrinogen is heterogeneous with three forms differing in length at the C-terminus. Alternative RNA splicing produces two gamma chain mRNAs encoding gamma 50 and gamma 57.5 polypeptides, while fibrinogen gamma 55 is produced by post- translational modification of the gamma 57.5 chain. The composition of purified variant gamma chain fibrinogens, which comprise 10% to 13% total plasma fibrinogen, is predominantly heterodimeric (A alpha, B beta, gamma 50/gamma 55 or A alpha, B beta, gamma 50/gamma 57.5), whereas the composition of purified fibrinogen with the major form of the gamma chain is homodimeric (A alpha, B beta, gamma 50/gamma 50). These gamma chain variations interrupt sequences that mediate platelet- fibrinogen interactions. Therefore, the structure and function of gamma 57.5 C-terminal sequences were investigated using synthetic peptides and a specific monoclonal antibody (MoAb), L2B. The L2B epitope was localized and included gamma 57.5 chain residues 409-412 (Arg-Pro-Glu- His), as determined by differential enzyme-linked immunosorbent assay (ELISA) reactivity with a His-412 deleted synthetic peptide and by Western blot analysis of plasmin cleaved fibrinogen gamma 57.5. L2B had no effect on adenosine diphosphate (ADP)-induced platelet aggregation supported by either fibrinogen gamma 50 or gamma 57.5. High concentrations (0.5 to 1 mmol/L) of synthetic peptide gamma 57.5 405- 416 only weakly inhibited ADP-induced platelet aggregation supported by either fibrinogen gamma 50 or gamma 57.5. Binding of fibrinogen gamma 50 (IC50 = 780 mumol/L) or gamma 57.5 (IC50 = 650 mumol/L) to ADP- stimulated platelets was weakly inhibited, and MoAb L2B failed to inhibit fibrinogen gamma 57.5 binding. Peptide gamma 57.5 408-416 failed to dissociate platelet-bound fibrinogens. These data indicate that the gamma 408-416 sequence of fibrinogen gamma 55 or gamma 57.5 alone is unlikely to bind to the platelet fibrinogen receptor, glycoprotein llb-llla (GPllb-llla), in support of platelet aggregation under physiologic conditions. The sequence recognized by L2B does not resemble known GPllb-llla binding site peptide sequences [Arg-Gly-Asp- Ser (RGDS) or gamma 50 400-411] as determined by competitive inhibition ELISA comparing these binding site synthetic peptides with gamma 57.5 408-416. This epitope is available for binding MoAb L2B in gamma 55 or gamma 57.5 chain dimers and binds to all gamma 57.5 408-416 epitopes equally in non-crosslinked and factor Xllla crosslinked fibrin clots.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
125.
126.
P-selectin expressed on the surface of endothelium mediates leukocyte adhesion in vitro and rolling in vivo. Several inducers of cell-surface P-selectin expression on endothelial cells (EC) have previously been identified, all of which yield transient cell-surface expression of P- selectin lasting minutes to a few hours. We now show that a T- lymphocyte product, interleukin-3 (IL-3), stimulates the long-term endothelial cells (HUVEC). IL-3 induced cell-surface P-selectin expression in two phases. An initial peak at 10 minutes was followed by a prolonged upregulation beginning 16 hours after IL-3 addition and lasting at least 4 days. The level of P-selectin expression induced by IL-3 added for 48 hours was similar to that induced by treatment of HUVEC for 10 minutes with thrombin, and the effect of adding IL-3 for 48 hours followed by thrombin for 10 minutes was additive. Induction of cell-surface P-selectin expression by IL-3 was blocked by pretreatment of EC with a blocking monoclonal antibody against the IL-3 receptor alpha-chain. Lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF alpha) and a mutant form of IL-3 with decreased potency did not induce cell-surface P-selectin expression after 48 hours' incubation with HUVEC, suggesting that the effect was specific to IL-3. The increase in cell-surface P-selectin expression occurring after 16 hours of incubation with IL-3 was accompanied by a similar prolonged increase in the steady-state mRNA level that was not observed at 10 minutes after IL-3 addition. As T-lymphocyte infiltration is a hallmark of chronic inflammation, our observations suggest that the secretion of IL-3 by T lymphocytes may serve to maintain the inflammatory state during chronic inflammation.  相似文献   
127.

Background:

Some kidney diseases are usually associated with changes in kidney size.

Objective:

To determine sonographically the normal limits and percentile curves of the kidney dimensions according to age, gender and somatometric parameters among school-age children.

Methods:

A prospective cross-sectional research design and convenience sampling method were utilized. Participants included 947 normal subjects (496 boys and 451 girls) aged 6–17 years old. The sonographic examination was performed on a Shenzhen DP-1100 machine with 3.5 MHz convex transducer. Longitudinal and transverse dimensions of the kidneys were obtained in coronal plane with the subject in the supine or left lateral decubitus position.

Results:

The means of right and left kidney lengths in mm were 79.6 ± 8.1 and 81.6 ± 8.3, respectively while those of the right and left kidney widths in mm were 35.03 ± 3.6 and 35.09 ± 3.6, respectively. Dimensions of the kidneys were not statistically different in boys and girls (p > 0.05). There was a statistically significant difference between right and left kidney length (p < 0.05). Height correlated best with both kidney lengths. Thus the normal limits, prediction models and percentile curves of kidney lengths were established with respect to height.

Conclusion:

Sonographic determination of pathologic changes in the size of the kidney necessitates knowing the normal ranges of its length especially with respect to height in school-age children.  相似文献   
128.
目的探讨健康信念模式在早期宫颈癌患者健康教育中应用价值。方法选取该院2013年1月—2014年6月收治的90例早期宫颈癌患者,随机分为两组,对照组和观察组各45例,对照组患者应用标准健康计划指导,观察组患者实施健康信念模式,比较两组患者采用不同的健康教育方式后患者对宫颈癌基本知识、自我保健知识的掌握情况。结果观察组患者对疾病知晓和掌握程度明显优于对照组,观察组掌握率高达93.3%(42/45),与对照组的75.6%(34/45)差异有统计学意义(P〈0.05);观察组自我保健知识掌握率为95.6%(43/45),对照组掌握率为82.2%(37/45),差异有统计学意义(P〈0.05);观察组对护理工作满意度显著高于对照组(P〈0.05)。结论对早期宫颈癌患者健康教育中采用健康信念模式具有明显的临床价值,有助于提升患者对疾病的认识,增强健康信念,养成良好的生活习惯,积极主动的做好预防措施,有效降低并发症发生率,值得在临床上进一步推广。  相似文献   
129.
Aims and objectives: To identify the factors that might affect the length of stay in the intensive care unit (ICU‐LOS) among cardiac surgery patients. Background: ICU‐LOS forms an important factor for assessing the effectiveness of the provided nursing care. A number of factors can be accused for increasing patient hospitalization. The nursing workload (NWL), among others, was found to play a significant role as it is closely associated with the quality of care. Design: An observational cohort study among 313 consecutive patients who were admitted to the cardiac surgery intensive care unit of a general, tertiary hospital of Athens, Greece from November 2008 to November 2009. Methods: Data collection was performed by using a short questionnaire (for basic demographic information) and two instruments, the Nursing Activities Score (NAS) and the logistic EuroSCORE, for assessing the NWL and the perioperative risk for each patient respectively. Results: ICU‐LOS of more than 2 days increased with age and was more common among females (p < 0·001 and p = 0·02, respectively). Multivariate logistic regression analysis revealed a positive association between increased perioperative risk and the increased ICU‐LOS [odd ratio (OR) 1·9, 95% confidence interval (CI) 1·0–3·5, p = 0·04], while patients with a first day NAS of more than 61·6% had an almost 5·2 times greater probability to stay in the cardiac surgery unit for more than 2 days (OR 5·2, 95% CI 3·0–8·8, p < 0·001). Conclusions: Increased level of NWL and patient perioperative risk are closely associated with increased ICU‐LOS. Relevance to clinical practice: The correlation between patient perioperative risk and ICU‐LOS encourages the early identification of high‐risk patients for prolonged hospitalization. Furthermore, the relationship between NWL and ICU‐LOS allows the early identification of these patients with the use of an independent nursing tool.  相似文献   
130.
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