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   109篇
  免费   7篇
耳鼻咽喉   2篇
儿科学   1篇
妇产科学   2篇
基础医学   12篇
口腔科学   2篇
临床医学   8篇
内科学   36篇
皮肤病学   3篇
神经病学   5篇
特种医学   1篇
外科学   23篇
预防医学   9篇
药学   3篇
中国医学   2篇
肿瘤学   7篇
  2023年   1篇
  2022年   2篇
  2021年   3篇
  2020年   1篇
  2018年   5篇
  2017年   3篇
  2016年   3篇
  2015年   6篇
  2014年   4篇
  2013年   4篇
  2012年   6篇
  2011年   15篇
  2010年   3篇
  2009年   9篇
  2008年   8篇
  2007年   5篇
  2006年   5篇
  2005年   6篇
  2004年   5篇
  2003年   4篇
  2002年   4篇
  2001年   1篇
  2000年   3篇
  1999年   3篇
  1994年   1篇
  1992年   1篇
  1991年   2篇
  1978年   2篇
  1975年   1篇
排序方式: 共有116条查询结果,搜索用时 46 毫秒
1.
Despite improvement in diagnostic modalities, confirmation of a histologic diagnosis of cancer of the biliary tree and pancreas remains elusive. Attempts to collect positive cytology specimens from vigorous brushings or washings obtained at endoscopy or percutaneously are often unsuccessful. In our unit, we have increased the yield by obtaining tissue scraped from prostheses that have been previously placed in either the bile duct or the pancreatic duct. The stents are first flushed with saline to collect cytology specimens, after which, they are bisected and scraped, and these contents are prepared in a manner similar to that used to prepare biopsy samples. Twelve of 16 scraped samples, 9 bile duct and 3 pancreas, were positive for adenocarcinoma. The cytology specimens were positive in only 4 of the 12. We recommend this method of sampling from material contained within prostheses as an adjunct when previous brushings, washings, or biopsies are negative.  相似文献   
2.

Objective

To evaluate the feasibility and outcome of the step‐down approach using either cyclosporin A (CSA) or methotrexate (MTX) as maintenance therapy following 6 months treatment with these 2 agents in combination in early, nonerosive rheumatoid arthritis (RA).

Methods

Fifty‐seven patients younger than 65 years with early, nonerosive RA were first treated with CSA and MTX in combination for 6 months. They were then randomly stepped down to single‐agent maintenance treatment for another 18 months. Safety, clinical efficacy, survival on treatment, and radiographic progression were evaluated.

Results

When being treated with combination therapy, 7 of the 57 patients (12.3%) withdrew because of adverse events. Of the remaining 50 patients, 42 (84.0%) were American College of Rheumatology (ACR) 20% responders, 30 (60.0%) were ACR 50% responders, and 23 (46.0%) were ACR 70% responders. At month 6, 22 patients were randomized to CSA and 27 to MTX. During this trial period, the treatment was discontinued by 16 patients taking CSA (mainly because of loss of efficacy) and by 4 taking MTX. At month 24, the probability (± SEM) of survival on treatment was 0.273 ± 0.09 for CSA and 0.852 ± 0.07 for MTX. Of the 6 CSA patients who completed the trial, 4 (66.7%) were ACR 20% responders, and 3 (50%) were both ACR 50% and ACR 70% responders. Of the 23 completers in the MTX arm, 21 (91.3%) were ACR 20% responders, 18 (78.3%) were ACR 50%, and 10 (43.5%) were ACR 70% responders. The treatment was not responsible for severe adverse events. Radiography showed a slow progression in the damage score and number of eroded joints in both treatment groups.

Conclusion

Stepping down to single agent maintenance therapy following 6 months of combination treatment with CSA and MTX in early RA was only successful with MTX. Because this treatment did not prevent some radiographic progression, other approaches (e.g., step‐up approach) may be more appropriate in early RA.
  相似文献   
3.
4.

OBJECTIVE:

To compare the absolute serum von Willebrand factor (vWF) levels and relative serum vWF activity in patients with clinically stable COPD, smokers without airway obstruction, and healthy never-smokers.

METHODS:

The study included 57 subjects, in three groups: COPD (n = 36); smoker (n = 12); and control (n = 9). During the selection phase, all participants underwent chest X-rays, spirometry, and blood testing. Absolute serum vWF levels and relative serum vWF activity were obtained by turbidimetry and ELISA, respectively. The modified Medical Research Council scale (cut-off score = 2) was used in order to classify COPD patients as symptomatic or mildly symptomatic/asymptomatic.

RESULTS:

Absolute vWF levels were significantly lower in the control group than in the smoker and COPD groups: 989 ± 436 pg/mL vs. 2,220 ± 746 pg/mL (p < 0.001) and 1,865 ± 592 pg/mL (p < 0.01). Relative serum vWF activity was significantly higher in the COPD group than in the smoker group (136.7 ± 46.0% vs. 92.8 ± 34.0%; p < 0.05), as well as being significantly higher in the symptomatic COPD subgroup than in the mildly symptomatic/asymptomatic COPD subgroup (154 ± 48% vs. 119 ± 8%; p < 0.05). In all three groups, there was a negative correlation between FEV1 (% of predicted) and relative serum vWF activity (r2 = −0.13; p = 0.009).

CONCLUSIONS:

Our results suggest that increases in vWF levels and activity contribute to the persistence of systemic inflammation, as well as increasing cardiovascular risk, in COPD patients.  相似文献   
5.
ATM (ataxia-telangiectasia mutated) gene plays a central role in the DNA-damage response pathway. We characterized the ATM protein expression in immortalized cells from AT and AT-variant patients, and heterozygotes and correlated it with two ATM-dependent radiation responses, G1 checkpoint arrest and p53-Ser 15 phosphorylation. On Western blots, the full-length ATM protein was detected in eight of 18 AT cases, albeit at 1-32% of the normal levels, whereas a truncated ATM protein was detected in a single case, despite the prevalence among cases of truncation mutations. Of two ataxia without telangiectasia [A-(T)] cases, one expressed 20% and the other approximately 70% of the normal ATM levels. Noteworthy, among ten asymptomatic heterozygous carriers for AT, normal amounts of ATM protein were found in one and reduced by 40-50% in the remaining cases. The radiation-induced phosphorylation of p53 protein at serine 15, largely mediated by ATM kinase, was defective in AT, A(-T) and in 2/4 heterozygous carriers, while the G1 cell cycle checkpoint was disrupted in all AT and A(-T) cases, and in 3/10 AT heterozygotes. Altogether, our study shows that AT and A(-T) cases bearing truncation mutations of the ATM gene can produce modest amounts of full-length (and only rarely truncated) ATM protein. However, this limited expression of ATM protein provides no benefit regarding the ATM-dependent responses related to G1 arrest and p53-ser15 phosphorylation. Our study additionally shows that the majority of AT heterozygotes express almost halved levels of ATM protein, sufficient in most cases to normally regulate the ATM-dependent DNA damage-response pathway.  相似文献   
6.
In this study, concentrations of dioxins and related compounds (DRCs)—such as polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls—were found in human breast milk from women living near dumping sites of municipal waste and reference sites in India, Cambodia, Vietnam, and the Philippines during 1999 to 2000. DRCs were detected in all human breast milk samples analyzed, demonstrating that residents in these Asian developing countries have been exposed to these contaminants. In India, the concentrations of DRCs in human breast milk from women living near the investigated dumping site were notably higher than those from women living near reference sites and from women in other Asian developing countries. Toxic equivalent quantity (TEQ) levels of DRCs were comparable with or higher than those reported in the general populations of developed countries since 1990. In contrast, levels of these contaminants in human breast milk in women from Cambodia and Vietnam were not significantly different between milk from women living near the dumping and reference sites. These results indicate that significant pollution sources for DRCs are present in Indian dumping sites and that residents there have been exposed to relatively higher levels of these contaminants. TEQ levels in human breast milk from the dumping site in India tended to decrease with an increase in the number of previous deliveries by mothers, whereas no significant relationship was observed in Cambodia, Vietnam, or the Philippines. This suggests that mothers who have been exposed to relatively high levels of DRCs transfer greater amounts of these contaminants to the first infant than later ones through breast-feeding, which in turn implies that the first children of these mothers might be at higher risk from DRCs. When the residue levels of DRCs in bovine milk collected from the Indian dumping site and reference sites were examined, TEQ levels in bovine milk from the dumping site were higher than those from reference sites. This result suggests that bovine milk is a potential source of DRCs for residents living near the dumping site in India. To our knowledge, this is the first comprehensive study on exposure to DRCs of residents living in proximity to open dumping sites of municipal waste in Asian developing countries.  相似文献   
7.
OBJECTIVE: To evaluate the feasibility and outcome of the step-down approach using either cyclosporin A (CSA) or methotrexate (MTX) as maintenance therapy following 6 months treatment with these 2 agents in combination in early, nonerosive rheumatoid arthritis (RA). METHODS: Fifty-seven patients younger than 65 years with early, nonerosive RA were first treated with CSA and MTX in combination for 6 months. They were then randomly stepped down to single-agent maintenance treatment for another 18 months. Safety, clinical efficacy, survival on treatment, and radiographic progression were evaluated. RESULTS: When being treated with combination therapy, 7 of the 57 patients (12.3%) withdrew because of adverse events. Of the remaining 50 patients, 42 (84.0%) were American College of Rheumatology (ACR) 20% responders, 30 (60.0%) were ACR 50% responders, and 23 (46.0%) were ACR 70% responders. At month 6, 22 patients were randomized to CSA and 27 to MTX. During this trial period, the treatment was discontinued by 16 patients taking CSA (mainly because of loss of efficacy) and by 4 taking MTX. At month 24, the probability (+/- SEM) of survival on treatment was 0.273 +/- 0.09 for CSA and 0.852 +/- 0.07 for MTX. Of the 6 CSA patients who completed the trial, 4 (66.7%) were ACR 20% responders, and 3 (50%) were both ACR 50% and ACR 70% responders. Of the 23 completers in the MTX arm, 21 (91.3%) were ACR 20% responders, 18 (78.3%) were ACR 50%, and 10 (43.5%) were ACR 70% responders. The treatment was not responsible for severe adverse events. Radiography showed a slow progression in the damage score and number of eroded joints in both treatment groups. CONCLUSION: Stepping down to single agent maintenance therapy following 6 months of combination treatment with CSA and MTX in early RA was only successful with MTX. Because this treatment did not prevent some radiographic progression, other approaches (e.g., step-up approach) may be more appropriate in early RA.  相似文献   
8.
9.
We sought to compare, by means of IVUS and OCT imaging, the performance of a novel sirolimus-eluting drug-eluting stent (DES) with biodegradable polymer (Inspiron?) to the Biomatrix? DES. From the DESTINY trial, a total of 70 randomized patients (2:1) were enrolled in the IVUS substudy (Inspiron?, n?=?46; Biomatrix?: n?=?20) while 25 patients were evaluated with OCT (Inspiron?, n?=?19; Biomatrix?: n?=?06) at 9-month follow-up. The main endpoints were % of neointimal tissue obstruction (IVUS) and neointimal stut coverage (OCT) at 9 months. Patients treated with both DES had very little NIH formation at 9 months either by IVUS (% of NIH obstruction of 4.9?±?4.1?% with Inspiron? vs. 2.7?±?2.9?% with Biomatrix?, p?=?0.03) or by OCT (neointimal thickness of 144.2?±?72.5 µm Inspiron? vs. 115.0?±?53.9 µm with Biomatrix?, p?=?0.45). Regarding OCT strut-level assessment, again both devices showed excellent 9-month performance, with high rates of strut coverage (99.49?±?1.01?% with Inspiron? vs. 97.62?±?2.21?% with Biomatrix?, p?<?0.001) and very rare malapposition (0.29?±?1.06?% with Inspiron? vs. 0.53?±?0.82?% with Biomatrix?, p?=?0.44). Patients with any uncovered struts were more frequently identified in the Biomatrix? group (9.78?±?7.13 vs. 2.29?±?3.91?%, p?<?0.001). In the present study, midterm IVUS and OCT evaluations showed that both new generation DES with biodegradable polymer were effective in terms of suppressing excessive neointimal response, with very high rates of apposed and covered struts, suggesting a consistent and benign healing pattern.  相似文献   
10.
Two cases of proven coral snake bites were reported in Belém, Pará State, Brazil. The first case was a severe one caused by Micrurus surinamensis. The patient required mechanical ventilation due to acute respiratory failure. The second case showed just mild signs of envenomation caused by Micrurus filiformis. Both patients received specific Micrurus antivenom and were discharged without further complications. Coral snake bites are scarcely reported in the Amazon region and there is a broad spectrum of clinical manifestations, varying from extremely mild to those which may rapidly lead to death if the patient is not treated as soon as possible.  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