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   308篇
  免费   27篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   8篇
妇产科学   11篇
基础医学   47篇
口腔科学   6篇
临床医学   35篇
内科学   55篇
皮肤病学   22篇
神经病学   28篇
特种医学   8篇
外科学   20篇
综合类   3篇
预防医学   43篇
眼科学   3篇
药学   26篇
肿瘤学   19篇
  2023年   3篇
  2022年   8篇
  2021年   15篇
  2020年   9篇
  2019年   14篇
  2018年   9篇
  2017年   14篇
  2016年   7篇
  2015年   14篇
  2014年   18篇
  2013年   14篇
  2012年   29篇
  2011年   31篇
  2010年   11篇
  2009年   12篇
  2008年   19篇
  2007年   13篇
  2006年   8篇
  2005年   19篇
  2004年   17篇
  2003年   14篇
  2002年   15篇
  2001年   1篇
  2000年   2篇
  1998年   1篇
  1997年   1篇
  1992年   2篇
  1990年   3篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1980年   1篇
  1973年   1篇
  1972年   1篇
  1969年   1篇
  1968年   2篇
  1966年   1篇
排序方式: 共有336条查询结果,搜索用时 328 毫秒
151.
As proviral human immunodeficiency virus type 1 (HIV-1) DNA can replenish and revive viral infection upon activation, its detection might offer significant therapeutic information, complementing the input provided by plasma RNA determination in the follow-up of infected individuals. A selected group of acutely infected subjects was studied to verify both total and 2-long terminal repeat (2-LTR) DNA proviral load during the acute phase of infection and thereafter. Patients were divided in two sex- and age-matched groups: 19 naive individuals who did not receive antiretroviral therapy during the observation period and 20 subjects treated according to current guidelines. Total and 2-LTR HIV-1 DNA proviral load, in addition to RNA viral load and CD4 cell count, were determined in peripheral blood mononuclear cells (PBMC) at baseline, 6 and 12 months after the first sampling. Total and 2-LTR HIV-1 DNA proviral load exhibited no significant variation at any time in the naive patients (total HIV-1 DNA ranging from 896 ± 731 to 715 ± 673 copies/105 PBMC and 2-LTR HIV-1 DNA ranging from 94 ± 105 to 65 ± 44 copies/105 PBMC), whereas a significant reduction in both total HIV-1 DNA (ranging from 997 ± 676 to 262 ± 174 copies/105 PBMC) and 2-LTR HIV-1 DNA proviral load (ranging from 116 ± 55 to 26 ± 35 copies/105 PBMC) was detected in highly active antiretroviral therapy (HAART) patients, together with a CD4+ T cell count increase and RNA load decrease. HAART negatively affects both the labile HIV burden and the integrated proviral DNA, at least in the initial period of successful treatment, suggesting that quantification of HIV-1 DNA proviral load may be an important parameter in monitoring HIV infection.  相似文献   
152.
Introduction and objectivesThe Dizziness Handicap Inventory is a useful tool for quantifying self-perceived handicap in patients with vertigo, dizziness or unsteadiness and its impact on daily living activities. The Dizziness Handicap Inventory identifies functional, physical and emotional disorders related to balance disturbance.Our objective was to cross-culturally adapt the Peninsular Spanish version of the Dizziness Handicap Inventory for use in Argentina and validate the adapted Argentinian version.MethodsWe included both healthy subjects and patients with vertigo, dizziness or unsteadiness, aged 18 to 85 years, native Spanish-speaking Argentinians.We introduced linguistic and cultural modifications to the Peninsular Spanish version to obtain the Argentinian one. This version was given twice to 108 patients, 24 to 72 h apart. Internal consistency, test-retest reliability and construct validity were assessed using a visual analogue scale, the Romberg test, the tandem Romberg test and the tandem gait test.ResultsWe found high internal consistency (α=0.87) and very high test-retest reliability for the total Dizziness Handicap Inventory score (intraclass correlation coefficient: 0.98) and its subscales. The total Dizziness Handicap Inventory and the functional subscale were found to correlate significantly with the Romberg and tandem Romberg tests. The emotional subscale showed a significant correlation with the Romberg test and the eyes-open tandem Romberg test (P<.05)ConclusionsThe Argentinian version of the Dizziness Handicap Inventory proved to be a reliable and valid tool to quantify self-perceived handicap resulting from vertigo, dizziness or unsteadiness.  相似文献   
153.
154.
Background: QT interval dispersion (QTID) as assessed on conventional surface electrocardiogram (ECG) has been used as a clinical tool to identify patients at high risk of ventricular arrhythmia. However, the results obtained have been controversial. The main purpose of this study was to compare QTID measured from an array of 5 × 6 electrodes homogeneously distributed against the values found when the 12‐lead standard ECG was used. Methods: QTID was calculated in a modified Langendorff‐perfused rabbit heart model immersed in a cylindrical chamber. Dispersion in ventricular repolarization was artificially increased by d‐sotalol (60 μ;m) perfusion. Results: All the duration variables measured from any of the lead systems used were significantly increased after d‐sotalol perfusion. The most commonly used variables in clinical studies, such as QTID (maximum ‐ minimum), do not reach a level of statistical significance, except when measured from the 30‐electrodes array or 15 electrodes covering the left or right side of the heart. The standard deviation of the QT interval (QTI) hardly reached a significant level (P = 0.0499) when calculated from the 12‐lead standard ECG. QTID measured at the peak of the T wave exhibited the highest level of significance when calculated from any of the lead systems used. Conclusion: Thirty electrodes homogeneously distributed on the body surface can better discriminate changes in heterogeneity of repolarization. These data further support the importance of multiple recording systems for the evaluation of QTID and may help to provide an understanding of the discrepancies found in clinical applications.  相似文献   
155.
AIM: To evaluate the relationships between the personal,sociocultural, and environmental characteristics, and the presence or absence of symptoms with the detection of Enterobius vermicularis ( E. vermicularis) in a population sample in our region (General Mansilla, Province of Buenos Aires, Argentina), by individual and familiar analyses.METHODS: E. vermicularis was diagnosed in 309 people from 70 family units residing in the urban area and the rural area of the city of General Mansilla. Each of them was surveyed so as to register personal, environmental and sociocultural data. Questions about the presence or absence of anal itch, abdominal pain and sleeping disorder were also asked. Significant associations were determined by square chi tests. Logistic regression models were adjusted by using a backward conditional stepwise method to determine the presence of this parasite in the individuals and in the families.RESULTS: The parasites were found in 29.12% (90/309) of the individuals, with a frequency of 14.28% (20/140) among the heads of the families and of 41.42% (70/169) among the children. The only variables showing a significant association were affiliation, where the risk category was “being the son/daughter of“, and the symptoms were abdominal pain, sleeping disorder, and anal itch. Families with a member infected with parasite were considered Positive Families (PF) and they were 40/70 (57.14%), only 5% (2/40) of the PF had 100% of their members infected with the parasite. The logistic regression models applied showed that the risk categories were mainly affiliation (son/daughter) and housing (satisfactory) among others.CONCLUSION: The presence of E. vermiculariswas proved in one third of the studied population. The frequency of families with all their members infected with the parasite was very low. Most of the studied personal, sociocultural,and environmental variables did not rum out to be significantly associated with the presence of the parasite. An association with the category of “son/daughter“ and housing classified as “satisfactory“ was determined. The latter may be due to the fact that the people living in that category of housing have hygienic practices at home that favour the distribution of the eggs in the environment. The presence of the analysed symptoms was associated with the presence of the parasite,thus strengthening the need of periodical control of the population showing at least one of these symptoms.  相似文献   
156.
157.

Background

Male breast cancer (MBC) is an uncommon disease that has been the focus of limited research. It is estimated that approximately 10% of men with breast cancer have a genetic predisposition, with BRCA2 being the most prevalent genetic mutation. Here we describe the case of MBC in a 64-year-old man who presented on physical examination a nodule in his left breast and declared to have an extensive family history of cancer.

Methods and results

The patient was firstly diagnosed with an invasive ductal carcinoma (IDC) with histological grade III, nuclear grade 3, pT4N2Mx and positive for hormonal receptors and HER2. Exome sequencing was performed by massive parallel sequencing which had detected a novel BRCA2 germline mutation that is a large genomic deletion of 3,492 nucleotides including BRCA2 exon 14, and this deletion is out of frame and is predicted to lead to a stop codon in exon 15 at codon 2,496.

Conclusion

Large rearrangements in BRCA1 and BRCA2 occur in a small percentage (<1%) of patients tested for hereditary breast and ovarian cancer. This is the first report of the mutation del3492 in BRCA2 exon 14, which leads to a truncated protein and therefore is clinically relevant. Mutation segregation analysis should be further done in the Brazilian population. Herein we highlight the importance of next-generation sequencing in the detection of large genomic deletions.  相似文献   
158.
Many challenges have been noted in the implementation of developmentally‐supportive care principles in neonatal intensive care units, despite evidence that adhering to such care principles achieves positive results for the neonate. The aim of this study was to explore and describe compliance in adhering to developmentally‐supportive care principles implemented in one neonatal intensive care unit in South Africa. An exploratory design was used in this qualitative study with purposive sampling to select eligible neonatal intensive care registered nurses (n = 14) as participants. Participants all worked in a 10 bed neonatal intensive care unit at a large tertiary care public hospital. Six audio‐recorded interviews were conducted, with recordings subsequently transcribed and analyzed. Three main themes were identified: value of developmentally‐supportive care, nature of developmentally‐supportive care, and barriers to developmentally‐supportive care. One of the main themes had subthemes, which substantiated the findings, and included parent involvement, nurse engagement, and holistic care. Study outcomes offer insight into the development or revision of policies and practices, which are crucial when implementing developmentally‐supportive care, particularly in resource‐poor settings where challenges are magnified.  相似文献   
159.
INTRODUCTION: The influence of activation sequence on the rate of rise of the depolarization phase of action potentials in atrial or ventricular muscles has been well established. However, whether myocardial fiber orientation is important in modulating the repolarization process is unclear. METHODS AND RESULTS: We examined the influence of activation sequence on the repolarization phase of action potentials in epicardial tissues from the right and left ventricles of domestic pigs. Whereas cells from the right ventricle exhibited direction-dependent differences in action potential duration at 30%, 50%, and 90% of full repolarization (190.6 +/- 31.1 msec vs 181.8 +/- 32.8 msec, 240.3 +/- 23.5 msec vs 236.7 +/- 25.4 msec, and 291.3 +/- 23.7 msec vs 287.4 +/- 25.1 msec for longitudinal and transverse propagation, respectively; P < 0.001), a similar duration of repolarization during both directions of propagation was observed in cells from the left ventricle at 50% and 90% of full repolarization (241.4 +/- 39.4 msec and 285.5 +/- 39.5 msec vs 240.4 +/- 38.9 msec and 284.9 +/- 39.6 msec for longitudinal and transverse propagation respectively; P = NS). A slight but significant difference was found at 30% of full repolarization in cells from the left ventricle (190.4 +/- 39.0 msec vs 187.0 +/- 38.0 msec for longitudinal and transverse propagation, respectively; P < 0.05). In the left ventricle, the duration of repolarization did not change as the distance between the recording site and stimulation site increased. CONCLUSION: The direction of wavefront propagation with respect to fiber orientation may not play an important role in modulating the duration of repolarization in epicardial cells from the left ventricle.  相似文献   
160.
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