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   310篇
  免费   21篇
  国内免费   2篇
儿科学   10篇
妇产科学   5篇
基础医学   49篇
口腔科学   35篇
临床医学   20篇
内科学   53篇
皮肤病学   16篇
神经病学   22篇
特种医学   5篇
外科学   29篇
综合类   3篇
预防医学   27篇
眼科学   3篇
药学   17篇
肿瘤学   39篇
  2023年   1篇
  2022年   2篇
  2021年   8篇
  2020年   8篇
  2019年   6篇
  2018年   10篇
  2017年   15篇
  2016年   6篇
  2015年   13篇
  2014年   19篇
  2013年   21篇
  2012年   23篇
  2011年   23篇
  2010年   12篇
  2009年   15篇
  2008年   26篇
  2007年   21篇
  2006年   18篇
  2005年   19篇
  2004年   9篇
  2003年   18篇
  2002年   16篇
  2001年   4篇
  2000年   3篇
  1999年   3篇
  1997年   1篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
排序方式: 共有333条查询结果,搜索用时 31 毫秒
1.
Breast carcinoma is a genetically and phenotypically heterogeneous disease and is frequently associated with nonrandom chromosomal alterations. The aim of this study was to investigate the numerical aberrations of chromosome 20 in breast cancer. The observed chromosome-specific numerical abnormalities were evaluated along with the established clinicopathological parameters, the immunohistochemical expression of ER, PR, p53, c-erbB-2, Ki-67 and patients' survival. Nonisotopic in situ hybridization was applied to interphase cell nuclei on paraffin embedded tissue sections. Polysomy of chromosome 20 was the prevalent alteration in 45 of 50 (90%), monosomy in 2 of 50 (4%) and disomy in 3 of 50 (6%) cases. Invasive ductal carcinomas displayed a higher percentage of polysomy than lobular ones. A statistical significant association was demonstrated between Ki-67 immunohistochemical expression and polysomy of chromosome 20. Disomy was inversely correlated with Ki-67, while monosomy was suggestively associated with PR positive expression. Among the patients, those with the highest levels of polysomy showed the worst survival. In conclusion, the gain of chromosome 20 is the prevalent aberration in patients with breast carcinomas and may be useful prognostic marker in breast cancer.  相似文献   
2.
AIMS: Oestrogen receptor beta (ERbeta) is present in breast tumours, although its prognostic and pathophysiological roles remain to be established. METHODS: Standard immunohistochemistry with a specific monoclonal antibody was performed on paraffin wax embedded sections; 10% of strongly immunostained carcinoma cells was used as the cutoff point to classify tumours as ERbeta positive. Statistical correlations were sought with clinicopathological variables (including hormone receptor status) and disease free (DFS) and overall survival (OS) in a well documented series of 181 invasive breast carcinomas. Cell proliferation was assessed immunohistochemically by topoisomerase IIa (TopoIIa) index; p53 protein accumulation and c-erbB-2 oncoprotein expression were also taken into account. RESULTS: ERbeta immunoreactivity was detected in most specimens (71.2%); it was positively linked to ERalpha immunoreactivity and increased TopoIIalpha index, and inversely to c-erbB-2 overexpression. There were no correlations with p53 immunostaining or other clinicopathological parameters. A significant favourable impact of ERbeta immunopositivity emerged with regard to DFS and OS in both univariate and multivariate analysis; ERbeta immunopositivity retained its favourable significance with regard to DFS in the subgroups of stage I and II patients when they were examined separately. Progesterone receptor expression also had an independent favourable influence on survival, albeit with less significance. In contrast, survival was not significantly influenced by ERalpha status. CONCLUSIONS: Because of the positive association between ERbeta immunoreactivity and TopoIIalpha expression, the presence of ERbeta in breast cancer cells could be considered an indication of increased proliferation. Nevertheless, ERbeta immunoreactivity emerges as a valuable, independent indicator of favourable prognosis.  相似文献   
3.
Tissue inhibitor of metalloproteinase-1 (TIMP-1) has emerged as a multifunctional protein with the contrasting activities of inhibiting tissue-degrading enzymes and promoting cellular growth. In an attempt to elucidate the clinical significance of TIMP-1 in breast cancer, the expression of TIMP-1 mRNA was evaluated in 117 invasive breast carcinomas by mRNA in situ hybridization, in correlation with clinicopathological parameters, immunohistochemical prognostic factors (Ki-67, c-erb-B-2, bcl-2) and clinical outcome. TIMP-1 was detected in stromal cells in areas within the tumours and at the tumour margin. High TIMP-1 mRNA expression in the marginal portion of the tumours was significantly correlated with lymph node metastasis (p<0.05) and c-erbB-2 expression (p<0.05). On the other hand, increased TIMP-1 mRNA expression within the tumours showed a statistically significant correlation with ER detection (p<0.01). Multivariate analysis revealed worse survival for patients with high TIMP-1 mRNA expression in the marginal portion of the tumours; the subgroup of these patients co-expressing high levels of TIMP-1 mRNA within the tumours as well had even worse survival (p=0.042). In conclusion, our data support the multifunctional role of TIMP-1, particularly its growth-promoting activity, on the basis of its significant correlation with lymph node metastasis and adverse prognosis. In addition to the latter property, a probable association of TIMP-1 with tumour cell differentiation is suggested by its topographical correlation with ER detection.  相似文献   
4.
Previous studies have shown that the diets of migrant populations are of poor quality; however, studies on populations remaining in one geographical region as a minority after an acute population movement are scarce. Therefore, the aim of the present study was to assess dietary intake and growth of Greek minority adolescents in Turkey. Anthropometric measurements and dietary assessment were performed in 103 Greek Orthodox students (aged 10–19 years old) of three minority schools in Istanbul. Prevalence of overweight and obesity according to the WHO growth charts was 39.8 %. Accordingly, 40 % of the sample exhibited excess body fat. Dietary intakes of protein, carbohydrate, fiber, vitamins E and D, folic acid and calcium were inadequate, while energy, total fat and iron intakes were considered adequate. Our results indicate that Greek minority adolescents living in Turkey have similar weight status compared to their counterparts in Greece, but greater body fat than Turkish coevals, while being at risk of several nutrient inadequacies.  相似文献   
5.
Reduced Axin expression has been associated with an aggressive behavior in lung and esophageal squamous cell carcinomas. Its role in breast cancer has not been defined. The aim of our study was to investigate the expression pattern of Axin protein in invasive breast carcinomas, in relation to the behavior and prognosis of the disease. Immunohistochemistry was performed for the detection of Axin expression in 232 breast cancer tissues. Univariate and multivariate statistical analyses were used to assess the relation of Axin expression with classic clinicopathological parameters, patients' survival and various biologic markers Human Epidermal Factor‐2 (HER‐2), Ki‐67, topoIIα, glycogen synthase kinase‐3β (GSK‐3β)]. Preserved cytoplasmic Axin expression was positively correlated to lymph node invasion, HER‐2 and GSK‐3β and inversely to Ki‐67 and topoIIα. Nuclear Axin was positively associated with tumor size. Stromal Axin showed a parallel association with lymph node status and HER‐2. In the subgroup of lobular breast carcinomas, preserved Axin was found to exert an unfavorable impact on patients' overall survival. Our findings indicate, for the first time, that in invasive breast cancer preserved Axin expression is associated with a more aggressive phenotype and that in the discrete subtype of lobular breast carcinomas Axin negatively influences patients' overall survival.  相似文献   
6.
Background Both chronic plaque psoriasis and periodontitis have an increasing prevalence worldwide and have been associated with the metabolic syndrome; however limited information is available on their association. Objective To evaluate the possible association of severe periodontitis and chronic plaque psoriasis. Methods This was a hospital based case‐control study. Chronic plaque psoriasis patients and age‐ and gender‐matched controls have been recruited. Baseline demographic data have been recorded. To explore correlations between different dichotomous variables the Sperman Rho correlation coefficient was used. Correlations were further explored non‐parametrically and univariate and multivariate logistic regression was utilized after adjustment for the effect of confounders. Results During the study enrolment period 100 patients with CPP and 100 age‐ and gender‐matched controls were included in this study. Mean age for both groups was 57.2 ± 5.3 years. 43% of patients and controls were males. Significant correlations where noted between psoriasis and 1) periodontitis (rho = 0.219, P = 0.02) and 2) metabolic syndrome (rho = 0.191, P = 0.07) using Spearman’s Rho correlation co‐efficient. Univariate logistic regression reported significant relations between psoriasis and periodontitis (OR = 3.329, 95%CI: 1.513–7.324, P = 0.003) and psoriasis and metabolic syndrome (OR = 2.293, 95%CI: 1.250–4.207, P = 0.007). On the contrary, a non‐significant relation between psoriasis and active smoking status was detected (OR = 1.041, 95%CI: 0.597–1.817, P = 0.887). In a multivariate analysis model we found a significant correlation of psoriasis and periodontitis when controlled for the presence of metabolic syndrome (OR: 2.486, 95%CI: 1.002–5.842, P = 0.049). Conclusion Periodontitis may be associated with psoriasis but further studies are required to elucidate their relationship in the context of the biologic plausibility.  相似文献   
7.
8.
Breath hydrogen monitoring after oral lactulose syrup is a conventional measure of mouth-to-cecum transit time (MCTT), but its reproducibility has been questioned. We compared the reproducibility of five measurements of MCTT after a conventional breakfast (380 kcal) taken with tea containing 20 g lactulose to five measurements of MCTT after 20 g lactulose in water in eight normal volunteers. Individual mean breakfast transit time was not significantly different from lactulose transit time in each of the seven subjects, but one had a breakfast transit time of 151±15 min and a lactulose transit time of 86±22 minutes (¯X ±sd, P<0.001). The coefficient of variation of breakfast transit time (11.6±5.3%, range: 6.9–24.2%) was less than that of lactulose transit time (30.7±7.8%, range: 22.1–50.0%, P<0.001). In a second set of experiments, the liquid phase marker ( 99m Technetiumdiethylene triamine pentaacetic acid) emptied from the stomach more rapidly after the lactulose solution (T1/2 16.3±5.4) than after the breakfast (33.9±10.9 min, P<0.01) and MCTT was shorter after lactulose (77±32 vs 104±40 min, trespectively, P<0.05). There was no correlation between MCTT of lactulose and breakfast and between half-time gastric emptying and MCTT of either lactulose or breakfast. We conclude that the ingestion of inert lactulose induces an abnormally rapid MCTT and that breakfast MCTT is a much more reproducible investigation and should be employed in studies requiring serial measurements.  相似文献   
9.
Objectives

The objective of this study was to evaluate the benefit of repeated subgingival cleaning with a low-concentrated hypochlorite/amino acid gel in subjects in maintenance care with residual pockets ≥ 5 mm.

Material and methods

Examiner masked, randomized two-arm parallel design. Thirty-two adult periodontal patients in maintenance phase, > 3 months after periodontal therapy, with at least one residual periodontal pocket ≥ 5 mm, were randomly assigned to treatment by subgingival ultrasonic debridement with the gel or ultrasonic debridement only. At months 0, 4, and 8, all sites presenting with a probing depth (PD) ≥ 5 mm were treated. Six sites were monitored on each tooth. The primary end point was the presence or absence of PD ≥ 5 mm after 12 months. Secondary clinical outcomes were oral tissue safety; patient acceptance; changes in PD; bleeding on probing; recession after 4, 8, and 12 months; and the presence or absence of six target microorganisms in treated pockets at baseline, after 7 days and 4 months.

Results

A total of 365 sites in 32 patients with PD ≥ 5 mm were treated at baseline. At the final evaluation at month 12, 47% of these sites in the test and 49% in the control group were still in this PD category. The difference between baseline and month 12 was significant in both groups (p < 0.01), whereas the difference between groups was not. Repeated short ultrasonic instrumentation with adjunctive administration of the test product resulted in a clinical attachment level (CAL) gain of 1.02 mm (p < 0.01) and led to − 0.97 mm of pocket reduction (p < 0.01) without inducing further recession. However, repeated short ultrasonic debridement without the gel led to a similar clinical outcome (p < 0.01). No adverse events were recorded.

Conclusions

Short ultrasonic instrumentation of residual pockets with PD ≥ 5 mm during maintenance visits resulted in a clinically relevant CAL gain and PD reduction in the order of 1 mm in 1 year, without inducing further recession.

Clinical relevance

This study corroborates the benefit of regular maintenance care after periodontal therapy, including short debridement of the residual pockets.

  相似文献   
10.
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