全文获取类型
收费全文 | 14253篇 |
免费 | 719篇 |
国内免费 | 52篇 |
学科分类
医药卫生 | 15024篇 |
出版年
2023年 | 116篇 |
2022年 | 254篇 |
2021年 | 534篇 |
2020年 | 239篇 |
2019年 | 364篇 |
2018年 | 470篇 |
2017年 | 328篇 |
2016年 | 398篇 |
2015年 | 385篇 |
2014年 | 562篇 |
2013年 | 777篇 |
2012年 | 1091篇 |
2011年 | 1144篇 |
2010年 | 604篇 |
2009年 | 447篇 |
2008年 | 784篇 |
2007年 | 787篇 |
2006年 | 706篇 |
2005年 | 628篇 |
2004年 | 571篇 |
2003年 | 465篇 |
2002年 | 431篇 |
2001年 | 305篇 |
2000年 | 310篇 |
1999年 | 256篇 |
1998年 | 109篇 |
1997年 | 76篇 |
1996年 | 91篇 |
1995年 | 76篇 |
1994年 | 48篇 |
1993年 | 46篇 |
1992年 | 120篇 |
1991年 | 162篇 |
1990年 | 128篇 |
1989年 | 107篇 |
1988年 | 108篇 |
1987年 | 75篇 |
1986年 | 85篇 |
1985年 | 89篇 |
1984年 | 65篇 |
1983年 | 68篇 |
1979年 | 66篇 |
1978年 | 44篇 |
1977年 | 35篇 |
1975年 | 34篇 |
1973年 | 38篇 |
1972年 | 41篇 |
1971年 | 44篇 |
1969年 | 32篇 |
1968年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Sandeep K. Jha Imtiakum Jamir Kshitij Sisodia Niteen Kumar Gaurav Sood Nitin Shanker Sachin Anand Gaurav Dubey Vinod Choudhary Pankaj Lohia Amit Singhal Manav Wadhawan Ajay Kumar Abhideep Chaudhary 《Transplantation proceedings》2021,53(4):1118-1125
IntroductionLiving-donor liver transplantation (LDLT) has been mostly suspended and deceased-donor living transplantation activity has been considerably reduced because of coronavirus disease 2019 (COVID-19). We modified our protocols and procedures in line with COVID-19 guidelines. Since the restructuring, we have performed 20 LDLTs. Our study reports the outcomes of these cases and demonstrates the feasibility of LDLT during this pandemic.Materials and MethodsThe changes were influenced by experiences and communications from across the globe. A month-long self-imposed moratorium was spent in restructuring the program and implementing new protocols. Twenty LDLTs were performed between April 18 and September 15 using the new protocols. Our experience includes 2 simultaneous liver-kidney transplants, 1 ABO-incompatible LDLT, and 1 pediatric case (age 11 months).ResultsNineteen patients recovered and 1 patient died. We maintained our postoperative immunosuppression protocol without many changes. Major complications were observed in 30% of recipients but none of the donors. One recipient was infected with COVID-19 during the postoperative period. A donor-recipient couple contracted COVID-19 after discharge from the hospital. All patients recovered from COVID-19 and liver enzymes were unaffected.ConclusionThis study represents a microcosm of experience in LDLT during the COVID-19 era. Outcomes of LDLT are not affected by COVID-19 per se, provided that we make necessary changes. 相似文献
102.
103.
BackgroundWith the improved health afforded by cystic fibrosis transmembrane conductance regulator (CFTR) modulators, pregnancy rates are increasing in women with CF. In animal reproductive models, the three components of elexacaftor-tezacaftor-ivacaftor (ETI) did not cause teratogenicity at normal human doses. Although the limited human data available in the literature for previously approved modulators did not suggest cause for concern, there is currently no data in the literature regarding use of ETI in pregnant women. Thus, the decision to continue therapy during pregnancy (with the associated unknown fetal impact) versus discontinuing therapy (with the known risk of maternal health decline) is challenging.MethodsCF Center staff completed an anonymous questionnaire regarding pregnancy and infant outcomes for women who used ETI during pregnancy and/or lactation.ResultsOf 45 ETI-exposed pregnancies reported to date, complications in 2 mothers and in 3 infants (2 born to mothers with poorly controlled diabetes) were rated by clinicians as unknown (possible) or suspected relatedness to ETI use. Two women terminated unplanned pregnancies. Miscarriage rates were consistent with that known in the general U.S. population. Five of the six women who discontinued ETI out of concern for unknown fetal risk restarted because of clinical deterioration. No infant cataracts were reported though only two infants were formally evaluated.ConclusionsIn the context of the known increased rate of complications in women with CF and their infants, data from this retrospective survey is reassuring for women who choose to continue ETI during pregnancy. However, a large, multi-center prospective study is needed to assess impact of use of ETI in pregnancy. 相似文献
104.
Douglas J Conrad Joanne Billings Charlotte Teneback Jonathan Koff Daniel Rosenbluth Barbara A Bailey Raksha Jain 《Journal of cystic fibrosis》2021,20(1):91-96
BackgroundCystic Fibrosis (CF) is a multi-systemic disorder resulting from genetic variation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene which can result in bronchiectasis, chronic sinusitis, pancreatic malabsorption, cholestatic liver disease and distal intestinal obstructive syndrome. This study generates multi-dimensional clinical phenotypes that capture the complexity and spectrum of the disease manifestations seen in adult CF patients using statistically robust techniques.MethodsPre-transplant clinical data from adult (age ≥18 years) CF patients (n = 992) seen in six regionally distinct US CF centers between 1/1/2014 and 6/30/2015 were included. Demographic, spirometry, nutritional, microbiological and therapy data were used to generate clusters using the Random Forests statistical-learning and Partitioning around Medoids (PAM) clustering algorithms. Five commonly measured demographic, physiological and nutritional parameters were needed to create the final phenotypes that are highly similar to a regionally matched group of patients from the CF Foundation Patient RegistryResultsThis approach identified high-risk phenotypes with expected characteristics including high rates of pancreatic insufficiency, diabetes and Pseudomonas aeruginosa colonization. It also identified unexpected populations including a) a male-dominated, well-nourished group with good lung function with a high prevalence of severe genotypes (i.e. 60% subjects had two minimal function CFTR variations), b) and an older, “survivor” phenotype that had high rates of chronic P. aeruginosa infection.ConclusionsThis study identified recognizable phenotypes that capture the clinical complexity in a statistically robust manner and which may aide in the identification of specific genetic and environmental factors responsible for these disease manifestation patterns. 相似文献
105.
106.
Rashi Jain Rinkee Kumari Sushmita Chakraborty Dipendra K. Mitra Anant Mohan Vijay Hadda Karan Madan Randeep Guleria 《European journal of immunology》2023,53(10):2250255
Sarcoidosis is a systemic inflammatory disorder characterized by tissue infiltration due to mononuclear phagocytes and lymphocytes and associated noncaseating granuloma formation. Pulmonary sarcoidosis (PS) shares a number of clinical, radiological, and histopathological characteristics with that of pulmonary tuberculosis (PTB). Due to this, clinicians face issues in differentiating between PS and PTB in a substantial number of cases. There is a lack of any specific biomarker that can diagnose PS distinctively from PTB. We compared T-cell-based signature cytokines in patients with PS and PTB. In this study, we proposed a serum biomarker panel consisting of cytokines from cells: T helper (Th) 1 [interferon-gamma (IFN-γ); tumor necrosis factor-alpha (TNF-α)], Th9 [interleukin (IL)-9], Th17 [IL-17], and T regulatory (Treg) [IL-10; transforming growth factor-beta (TGF-β)]. We performed the principal component analysis that demonstrated that our serum cytokine panel has a significant predictive ability to differentiate PS from PTB. Our results could aid clinicians to improve the diagnostic workflow for patients with PS in TB endemic settings where the diagnosis between PS and PTB is often ambiguous. 相似文献
107.
The clinical profile of typhoid fever in an infant is variable and non-specific. A rare case of typhoid fever in a 7 month old infant is reported. The child presented with only a day's history of fever and loose motions which resulted in severe dehydration, acute tubular necrosis and death. The diagnosis of typhoid fever was made only on post-mortem study. The problem in diagnosing typhoid fever in a young infant is highlighted with a brief literature review on the subject. 相似文献
108.
S K Kabra Y Jain R M Pandey T MadhulikaSinghal P Tripathi S Broor P Seth V Seth 《Transactions of the Royal Society of Tropical Medicine and Hygiene》1999,93(3):294-298
An epidemic of dengue haemorrhagic fever (DHF) occurred in Delhi in 1996. A total of 240 children between the age of 4 months to 13 years of either sex, admitted in one hospital, were evaluated. Two hundred and sixteen (90%) children were from Delhi. A clinical diagnosis of dengue fever (DF) was made in 25 (10%), dengue fever with unusual bleeding (DFB) in 22 (9%), DHF in 80 (33%) and dengue shock syndrome (DSS) in 113 (47%) of the children strictly according to the WHO classification. The age peaked at 8 years. There was no association between various grades of severity of illness and age-groups though girls suffered from more severe illness. No association between severity of malnutrition and severity of illness was observed. Tourniquet test was positive in 40% with DF, 18% with DFB, 62% with DHF and 64% with DSS. In DSS haematemesis was present in 55 (49%), epistaxis in 39 (35%), melaena in 27 (24%) and ecchymosis in 34 (30%) patients. Children diagnosed as DFB had haematemesis and epistaxis in 12 (55%) and 10 (45%) respectively. Intravenous fluid requirement was clearly less in DFB patients than in DHF/DSS patients. Unusual clinical features in the form of jaundice were present in 7 (6%), hepatic encephalopathy in 6 (5%) and dengue encephalopathy in 6 (5%) patients. Dengue 2 virus was isolated from 10 of the 50 patients for whom viral culture was done on C6/36 clone of Aedes albopictus cell line. Eighteen patients suffering from DSS died giving an overall case fatality of 7.5%. The mortality rate in DHF/DSS was 9.3%. It is further suggested that DFB is a distinct entity. Most patients could be classified by the WHO classification if a retrospective packed cell volume was used to assess haemoconcentration. We suggest that development of area-specific criteria for diagnosis and management is desirable. 相似文献
109.
Transplantation has come of age as an important investigative tool for studying normal growth and development of the brain tissue. The present study reports the effect of lateral hypothalamic (LHA) lesion and foetal hypothalamic tissue transplantation on the feeding behaviour. In a group of rats, LHA was lesioned bilaterally by passing direct current. Subsequently, in a separate group of rats, foetal hypothalamic tissue was transplanted at the lesioned site. Following LHA lesion, all the rats died of aphagia and adipsia within 7 days, whereas, the rats in whom foetal hypothalamus was transplanted, started taking food and water in small quantities from the first day of transplantation itself. Later, they were able to attain their preoperative values. This recovery of the feeding behaviour following foetal tissue transplantation may be due to the formation of synaptic connections or due to the release of neurotrophic factors. 相似文献
110.