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   375篇
  免费   19篇
  国内免费   5篇
儿科学   12篇
妇产科学   18篇
基础医学   41篇
口腔科学   7篇
临床医学   30篇
内科学   67篇
皮肤病学   4篇
神经病学   22篇
特种医学   6篇
外科学   74篇
综合类   12篇
预防医学   27篇
眼科学   10篇
药学   39篇
中国医学   7篇
肿瘤学   23篇
  2023年   8篇
  2022年   16篇
  2021年   24篇
  2020年   7篇
  2019年   21篇
  2018年   21篇
  2017年   13篇
  2016年   7篇
  2015年   16篇
  2014年   24篇
  2013年   24篇
  2012年   35篇
  2011年   37篇
  2010年   21篇
  2009年   12篇
  2008年   18篇
  2007年   24篇
  2006年   20篇
  2005年   16篇
  2004年   13篇
  2003年   7篇
  2002年   5篇
  2001年   2篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1995年   1篇
  1990年   1篇
  1966年   1篇
排序方式: 共有399条查询结果,搜索用时 250 毫秒
131.
We have obtained evidence that oncogenic and activated normal ras-p21 proteins utilize overlapping but distinct signal transduction pathways. Recently, we found that ras-p21 binds to both jun and its kinase, jun kinase (JNK). We now present evidence that suggests that oncogenic but not normal activated p21 depends strongly on early activation of JNK/jun. This early activation most likely involves direct interaction between oncogenic p21 and JNK/jun because p21 peptides that blocked the binding of p21 to JNK and jun strongly inhibited oncogenic p21-induced oocyte maturation while they did not inhibit insulin-activated normal cellular p21-induced maturation. Very similar results were also obtained for a newly characterized specific inhibitor of JNK which blocked oncogenic but not normal activated p21-induced oocyte maturation. We also found that both jun and JNK strongly enhanced oncogenic p21-induced oocyte maturation while they inhibited insulin-activated normal p21-induced oocyte maturation. These results suggest that the peptides and JNK inhibitor may be useful agents in selectively blocking the effects of oncogenic but not normal p21 in cells. Received: 8 January 1997 / Accepted: 4 April 1997  相似文献   
132.
133.
Ciliopathies are a clinically and genetically heterogeneous group of disorders often exhibiting phenotypic overlap and caused by abnormalities in the structure or function of cellular cilia. As such, a precise molecular diagnosis is important for guiding clinical management and genetic counseling. In the present study, two Pakistani families comprising individuals with overlapping clinical features suggestive of a ciliopathy syndrome, including intellectual disability, obesity, congenital retinal dystrophy, and hypogonadism (in males), were investigated clinically and genetically. Whole‐exome sequencing identified the likely causes of disease as a novel homozygous frameshift mutation (NM_152384.2: c.196delA; p.(Arg66Glufs*12); family 1) in BBS5, and a nonsense mutation (NM_019892.5:c.1879C>T; p.Gln627*; family 2) in INPP5E, previously reported in an extended Pakistani family with MORM syndrome. Our findings expand the molecular spectrum associated with BBS5 mutations in Pakistan and provide further supportive evidence that the INPP5E mutation is a common cause of ciliopathy in Northern Pakistan, likely representing a regional founder mutation. This study also highlights the value of genomic studies in Pakistan for families affected by rare heterogeneous developmental disorders and where clinical phenotyping may be limited by geographical and financial constraints. The identification of the spectrum and frequency of disease‐causing variants within this setting enables the development of population‐specific genetic testing strategies targeting variants common to the local population and improving health care outcomes.  相似文献   
134.

Objectives

Hypertriglyceridemic (HTG) pancreatitis carries significant morbidity and mortality and often requires intensive care unit (ICU) admission. Therapeutic plasma exchange (TPE) rapidly lowers serum triglyceride (TG) levels. However, evidence supporting TPE for HTG pancreatitis is lacking.

Methods

Ten patients admitted to the ICU for HTG pancreatitis underwent TPE at our institution from 2005–2015. We retrospectively calculated the Acute Physiology and Chronic Health Examination II (APACHE II) score at the time of initial TPE and again after the final TPE session to assess the impact of triglyceride apheresis on morbidity and mortality associated with HTG pancreatitis.

Results

All 10 patients had rapid reduction in TG level after TPE, but only 5 had improvement in their APACHE II score. The median APACHE II score decreased from 19% to 17% after TPE, correlating with an 8% and 9% decrease in median predicted non-operative and post-operative mortality, respectively. The APACHE II score did not differ statistically before and after TPE implementation in our patient group (p = 0.39).

Conclusion

TPE is a clinically useful tool to rapidly lower TG levels, but its impact on mortality of HTG pancreatitis as assessed by the APACHE II score remains uncertain.  相似文献   
135.
Nephrotic syndrome (NS) is divided into steroid-sensitive (SSNS) and -resistant (SRNS) variants. SRNS causes end-stage kidney disease, which cannot be cured. While the disease mechanisms of NS are not well understood, genetic mapping studies suggest a multitude of unknown single-gene causes. We combined homozygosity mapping with whole-exome resequencing and identified an ARHGDIA mutation that causes SRNS. We demonstrated that ARHGDIA is in a complex with RHO GTPases and is prominently expressed in podocytes of rat glomeruli. ARHGDIA mutations (R120X and G173V) from individuals with SRNS abrogated interaction with RHO GTPases and increased active GTP-bound RAC1 and CDC42, but not RHOA, indicating that RAC1 and CDC42 are more relevant to the pathogenesis of this SRNS variant than RHOA. Moreover, the mutations enhanced migration of cultured human podocytes; however, enhanced migration was reversed by treatment with RAC1 inhibitors. The nephrotic phenotype was recapitulated in arhgdia-deficient zebrafish. RAC1 inhibitors were partially effective in ameliorating arhgdia-associated defects. These findings identify a single-gene cause of NS and reveal that RHO GTPase signaling is a pathogenic mediator of SRNS.  相似文献   
136.

Purpose

Detection of osteomyelitis beneath a diabetic foot ulcer is imperative for proper management; however, accurate and noninvasive diagnosis of osteomyelitis remains a challenge. Ubiquicidin 29-41 (UBI 29-41) is a synthetic antimicrobial peptide fragment reported to be highly infection-specific. 99mTc-UBI 29-41 has recently been reported to be a promising radiotracer for infection imaging. The aim of this prospective study was to evaluate the utility of 99mTc-UBI 29-41 scintigraphy in diabetic patients with suspected osteomyelitis of the foot.

Methods

Included in the study were 65 patients with type 2 diabetes mellitus and foot ulcer and with clinical suspicion of osteomyelitis . Each patient had a three-phase bone scan and a 99mTc-UBI scan at 30 and 60 min after injection. The scan was considered to be consistent with osteomyelitis when the 99mTc-UBI 29-41 uptake was concordant with the 99mTc-MDP uptake. It was considered negative for osteomyelitis if there was no uptake of 99mTc-UBI 29-41 or if 99mTc-UBI 29-41 accumulated in an area not concordant with the abnormal uptake of 99mTc-MDP on the bone scan. In the latter case a diagnosis of soft-tissue infection was made. Bone infection was confirmed by bone biopsy/culture and by clinical and radiological follow-up.

Results

Final analysis was done in 55 patients. Osteomyelitis was confirmed in 37 patients, and 18 patients were free of bone infection. 99mTc-UBI 29-41 was positive in all 37 patients and with the bone scan as the reference for the bone identified all osteomyelitic foci (68 in total). 99mTc-UBI 29-41 was negative for osteomyelitis in all 18 patients, and 17 of these patients were diagnosed with soft-tissue infection (99mTc-UBI 29-41 accumulation without concordant abnormal uptake on bone scintigraphy). The sensitivity, specificity and accuracy of 99mTc-UBI 29-41 scan in combination with three-phase bone scan for the diagnosis of osteomyelitis in diabetic foot was 100 %. Accuracy for soft-tissue infection was also 100 %. Maximum accumulation of the 99mTc-UBI 29-41 with maximum target to background activity was observed in the infectious foci at 30 min after injection.

Conclusion

Tc-UBI 29-41 may be a useful agent for the accurate diagnosis of bone infection in diabetic foot because of the high accuracy demonstrated in this pilot study. It was able to differentiate between bone and soft-tissue involvement effectively in combination with a bone scan.  相似文献   
137.

Objective

We aimed to determine the association of FSWs typology with condom use among HIV high risk groups in Sindh, Pakistan

Introduction

HIV is growing rapidly worldwide resulting in estimated 34 million population [1]. Recently, its epidemic has spread in Africa, Latin America, and the Caribbean, and most parts of Asia [2]. According to Antenatal sero surveillance study conducted in 2011 by Agriteam canada, it’s prevalence in Pakistan is <0.1 [3].Focusing narrowly, its prevalence in Sindh, (one of the provinces of Pakistan) is similar in general population, but it is in the phase of concentrated epidemic (having more than 5% of prevalence in high risk groups)in vulnerable groups like IDUs and Male sex workers and transgender [4].Sexual intercourse has been identified as major route especially in HIV high risk groups including male sex workers, female sex workers (FSWs), transgender (hijras) and IV drug users. Among them, FSWs are at high risk because of unprotected sex and illicit drug use. Their prevalence is found to be 30.7% in low and middle income countries [5]. South Asia contributed with 12.63 lakh FSW in India only [6]. On the basis of their station of work, they are categorized into facility based (kothikhana, brothel or home) and mobile (street, mobile or beggars). They use different preventive measures including condom for their protection from HIV [7]. It varies with availability and access [8] . FSWs typology have different cliental and mode of action, therefore, it important to explore the preventive methods.

Methods

Data was extracted from Second Generation Surveillance, Integrated behavioral and biological survey, Round IV for HIV infection conducted by Agriteam Canada in partnership with National AIDS Control Program, Pakistan in 2011. It was a cross sectional survey for high risk groups including FSWs from Pakistan. It was ethically approved by Review Board of the Public Health Agency of Canada and HOPE International’s Ethical Review Board, Pakistan. From Sindh province, FSWs based in Karachi, Sukkur and Larkana were recruited. Considering typology, they were categorized as mobile or facility based. After informed consent, socio-demographic and risk behavior were inquired. HIV was tested by ELISA/EIA and confirmed by Western Blot. Data was analyzed on SPSS 19. Continuous variables were expressed as mean±SD while categorical as frequency(%). Logistic regression assessed the association of FSWs typology with condoms use among HIV high risk groups.

Results

Out of 4567 high risk population, 1127 were identified as FSWs. Mean age was 26.9 years. Most of them were facility based (72.8%) and 81.3% used condoms. Typology, age, education, duration of involvement, number of client per day, number of paid oral sex per month, knowledge about STI and knowledge about drop in center were significantly associated with condom use among HIV high risk groups.

Conclusions

Majority of facility based FSWs use condoms to prevent HIV infection. Awareness and access to home based FSWs should be increased. It may help in targeting and designing preventive strategies for them at government and mass level.  相似文献   
138.
ObjectivesThe aim of this study was to compare the efficacy of vaginal misoprostol with vaginal dinoprostone for term labor induction.Material and MethodsIt was a randomized controlled trial done in the Obstetrics Department, Shifa Community Health Centre, Shifa International Hospital (Teaching Hospital of Shifa College of Medicine, Islamabad). All pregnant women at term pregnancy coming for induction of labor were enrolled. 246 women fulfilled the inclusion criteria. Out of them 208 women consented to be part of the study. These women were then randomized to receive either Treatment A (vaginal misoprostol) or Treatment B (vaginal dinoprostone). Data were completed for 200 women. These included induction labor and induction-delivery interval, fetal and maternal complications, and baby apgar score.ResultsOut of 200 women in the study, 100 were in Group A and 100 in Group B. Labor commenced in a mean of 6.67 hours (±3.63) in Group A whereas it took a mean of 8.41 hours (±5.13) in Group B (p = 0.00). Actual induction to delivery (of the baby) interval was a mean of 11.68 hours (±4.55) for misoprostol and 15.37 hours (±5.30) for dinoprostone group (p = 0.00). There were no cases of uterine rupture in both groups; however, there were 10 cases of uterine hyperstimulation in Group A and 4 in Group B (p = 0.09).ConclusionsIt is time to re-evaluate the role of misoprostol for term labor induction. It is an efficacious and cost-effective alternative to the presently licensed treatment.  相似文献   
139.

IMPORTANCE

Diagnostic errors are common and harmful, but difficult to define and measure. Measurement of diagnostic errors often depends on retrospective medical record reviews, frequently resulting in reviewer disagreement.

OBJECTIVES

We aimed to test the accuracy of an instrument to help detect presence or absence of diagnostic error through record reviews.

DESIGN

We gathered questions from several previously used instruments for diagnostic error measurement, then developed and refined our instrument. We tested the accuracy of the instrument against a sample of patient records (n?=?389), with and without previously identified diagnostic errors (n?=?129 and n?=?260, respectively).

RESULTS

The final version of our instrument (titled Safer Dx Instrument) consisted of 11 questions assessing diagnostic processes in the patient–provider encounter and a main outcome question to determine diagnostic error. In comparison with the previous sample, the instrument yielded an overall accuracy of 84 %, sensitivity of 71 %, specificity of 90 %, negative predictive value of 86 %, and positive predictive value of 78 %. All 11 items correlated significantly with the instrument’s error outcome question (all p values?≤?0.01). Using factor analysis, the 11 questions clustered into two domains with high internal consistency (initial diagnostic assessment, and performance and interpretation of diagnostic tests) and a patient factor domain with low internal consistency (Cronbach’s alpha coefficients 0.93, 0.92, and 0.38, respectively).

CONCLUSIONS

The Safer Dx Instrument helps quantify the likelihood of diagnostic error in primary care visits, achieving a high degree of accuracy for measuring their presence or absence. This instrument could be useful to identify high-risk cases for further study and quality improvement.
  相似文献   
140.
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