收费全文 | 13715篇 |
免费 | 854篇 |
国内免费 | 95篇 |
耳鼻咽喉 | 163篇 |
儿科学 | 353篇 |
妇产科学 | 199篇 |
基础医学 | 1657篇 |
口腔科学 | 287篇 |
临床医学 | 1415篇 |
内科学 | 3076篇 |
皮肤病学 | 202篇 |
神经病学 | 747篇 |
特种医学 | 361篇 |
外国民族医学 | 4篇 |
外科学 | 2467篇 |
综合类 | 322篇 |
现状与发展 | 1篇 |
一般理论 | 8篇 |
预防医学 | 834篇 |
眼科学 | 304篇 |
药学 | 1246篇 |
中国医学 | 207篇 |
肿瘤学 | 811篇 |
2024年 | 23篇 |
2023年 | 241篇 |
2022年 | 698篇 |
2021年 | 913篇 |
2020年 | 538篇 |
2019年 | 681篇 |
2018年 | 727篇 |
2017年 | 453篇 |
2016年 | 486篇 |
2015年 | 532篇 |
2014年 | 677篇 |
2013年 | 807篇 |
2012年 | 1290篇 |
2011年 | 1163篇 |
2010年 | 576篇 |
2009年 | 488篇 |
2008年 | 720篇 |
2007年 | 683篇 |
2006年 | 608篇 |
2005年 | 539篇 |
2004年 | 422篇 |
2003年 | 413篇 |
2002年 | 253篇 |
2001年 | 92篇 |
2000年 | 77篇 |
1999年 | 60篇 |
1998年 | 55篇 |
1997年 | 30篇 |
1996年 | 32篇 |
1995年 | 16篇 |
1994年 | 24篇 |
1993年 | 24篇 |
1992年 | 28篇 |
1991年 | 29篇 |
1990年 | 18篇 |
1989年 | 20篇 |
1988年 | 26篇 |
1987年 | 24篇 |
1986年 | 9篇 |
1985年 | 22篇 |
1984年 | 15篇 |
1983年 | 8篇 |
1982年 | 8篇 |
1981年 | 15篇 |
1980年 | 10篇 |
1978年 | 11篇 |
1977年 | 8篇 |
1975年 | 8篇 |
1974年 | 8篇 |
1973年 | 11篇 |
Background:
Kidney disease is a common complication of human immunodeficiency virus (HIV) infection even in the era of antiretroviral therapy, with kidney function being abnormal in up to 30% of HIV-infected patients. We determined the predictors of impaired renal function in HIV-infected adults initiating highly active antiretroviral therapy (HAART) in Nigeria.Materials and Methods:
This was a retrospective study among HIV-1 infected patients attending the antiretroviral clinic at the Jos University Teaching Hospital (JUTH), between November 2005 and November 2007. Data were analysed for age, gender, weight, WHO clinical stage, CD4 count, HIV-1 RNA viral load, HBsAg and anti-HCV antibody status. Estimated glomerular filtration rate (eGFR) was calculated using the Cockcroft-Gault equation. Statistical analysis was done using Epi Info 3.5.1.Results:
Data for 491 (294 females and 197 males) eligible patients were abstracted. The mean age of this population was 38.8±8.87 years. One hundred and seventeen patients (23.8%; 95% CI, 20.2-27.9%) had a reduced eGFR (defined as <60 mL/min), with more females than males (28.6% vs. 16.8%; P=0.02) having reduced eGFR. Age and female sex were found to have significant associations with reduced eGFR. Adjusted odds ratios were 1.07 (95% CI, 1.04, 1.10) and 1.96 (95% CI, 1.23, 3.12) for age and female sex, respectively.Conclusions:
Older age and female sex are independently associated with a higher likelihood of having lower eGFRs at initiation of HAART among our study population. We recommend assessment of renal function of HIV-infected patients prior to initiation of HAART to guide the choice and dosing of antiretroviral drugs. 相似文献Background and Aim:
Arterial carbon dioxide tension (PaCO2) is considered the gold standard for scrupulous monitoring in pediatric intensive care unit (PICU), but it is invasive, laborious, expensive, and intermittent. The study aims to explore when we can use end-tidal carbon dioxide tension (PETCO2) as a reliable, continuous, and noninvasive monitor of arterial CO2Materials and Methods:
Concurrent PETCO2, fraction of inspired oxygen, PaCO2, and arterial oxygen tension values of clinically stable children on mechanical ventilation were recorded. Children with extra-pulmonary ventriculoatrial shunts were excluded. The PETCO2 and PaCO2 difference and its variability and reproducibility were studied.Results:
A total of 624 concurrent readings were obtained from 105 children (mean age [SD] 5.53 [5.43] years) requiring invasive bi-level positive airway pressure ventilation in the PICU. All had continuous PETCO2 monitoring and an arterial line for blood gas measurement. The mean (SD) number of concurrent readings obtained from each child, 4-6 h apart was 6.0 (4.05). The PETCO2 values were higher than PaCO2 in 142 observations (22.7%). The PaCO2–PETCO2 difference was individual admission specific (ANOVA, P < 0.001). The PaCO2–PETCO2 difference correlated positively with the alveolar-arterial oxygen tension [P(A-a)O2] difference (ρ = 0.381 P < 0.0001). There was a fixed bias between the PETCO2 and PaCO2 measuring methods, difference +0.66 KPa (95% confidence interval: +0.57 to +0.76).Conclusions:
The PaCO2–PETCO2 difference was individual specific. It was not affected by the primary disorder leading to the ventilation. 相似文献Methods: Complete ophthalmic examinations were performed for available affected family members. All PAX6 exons and their flanking regions were sequenced for affected individuals. Candidate variation was screened for segregation in the pedigree by Sanger sequencing. Bioinformatics prediction was done to evaluate the deleterious effects of the mutation on protein product. Real-time PCR was used to investigate the impact of the variant on PAX6 mRNA expression.
Results: All patients were diagnosed with isolated aniridia associated with variable phenotypic features including retinal detachment. A novel heterozygous deletion c.320_348delTGTCCGAGGGGGTCTGTACCAACGATAAC (p.Leu107HisfsX16) on PAX6 gene was detected. Decreased mRNA level of PAX6 in the affected individuals indicated that the mutation caused nonsense-mediated mRNA decay (NMD).
Conclusions: To the best of our knowledge, it is the first report on the genetics of aniridia in Iran. Segregation analysis, bioinformatics prediction and confirmation of NMD, all support the proposition that the novel observed PAX6 mutation is the cause of aniridia in the pedigree. Retinal detachment in some of the affected members, which is a rare reported phenotypic feature of aniridia patients, may be associated with this mutation. 相似文献
Exceptional precautionary measures have been adopted to stop the transmission and control of COVID-19 through the world and Pakistan is facing lockdown in this scenario. Public loyalty to precautionary measures is affected by their knowledge, attitude, risk factors and practices (KAP) towards COVID-19. The present study was conducted among the Pakistani residents to observe the knowledge, attitude, practices and risk factors towards COVID-19 outbreak in Pakistan. A questionnaire was designed, and a cross-sectional survey was conducted among participants of the study area. Participants were asked the questions regarding knowledge, attitude, practices and risk factors towards COVID-19. Data were analyzed by SPSS and t/F test and correlation was applied among the knowledge, attitude, risk factors and practices. A total of 1060 questionnaires were received. 1004 were included while 56 were excluded. The highest representation was from Punjab province (65.6%), female (63%) and age group of 21–30 years (62.1%). Most participants were single (85%), Muslim (99.4%), Urdu speaking (45.6%) and were graduates (51.5%). Most of the participants were students (52.9%) and were from economically middle-class families (40.8%). The knowledge was positively correlated with attitude and practices whereas negatively correlated with risk factors (P?<?0.05). The attitude was negatively correlated with risk factor and positively correlated with practices. The risk factors and practices were positively correlated with each other. Health education program to improve the COVID-19 knowledge, attitude, practices and risk factors should be initiated to combat current health challenge.
相似文献