全文获取类型
收费全文 | 23506篇 |
免费 | 1853篇 |
国内免费 | 96篇 |
专业分类
耳鼻咽喉 | 260篇 |
儿科学 | 447篇 |
妇产科学 | 282篇 |
基础医学 | 3238篇 |
口腔科学 | 447篇 |
临床医学 | 2966篇 |
内科学 | 5342篇 |
皮肤病学 | 446篇 |
神经病学 | 2308篇 |
特种医学 | 729篇 |
外国民族医学 | 3篇 |
外科学 | 3454篇 |
综合类 | 242篇 |
现状与发展 | 1篇 |
一般理论 | 10篇 |
预防医学 | 1561篇 |
眼科学 | 373篇 |
药学 | 1549篇 |
中国医学 | 68篇 |
肿瘤学 | 1729篇 |
出版年
2023年 | 132篇 |
2022年 | 274篇 |
2021年 | 567篇 |
2020年 | 385篇 |
2019年 | 607篇 |
2018年 | 695篇 |
2017年 | 507篇 |
2016年 | 534篇 |
2015年 | 657篇 |
2014年 | 838篇 |
2013年 | 1115篇 |
2012年 | 1782篇 |
2011年 | 1953篇 |
2010年 | 940篇 |
2009年 | 897篇 |
2008年 | 1476篇 |
2007年 | 1487篇 |
2006年 | 1388篇 |
2005年 | 1417篇 |
2004年 | 1274篇 |
2003年 | 1131篇 |
2002年 | 1154篇 |
2001年 | 281篇 |
2000年 | 249篇 |
1999年 | 278篇 |
1998年 | 232篇 |
1997年 | 191篇 |
1996年 | 134篇 |
1995年 | 135篇 |
1994年 | 104篇 |
1993年 | 104篇 |
1992年 | 185篇 |
1991年 | 168篇 |
1990年 | 151篇 |
1989年 | 139篇 |
1988年 | 143篇 |
1987年 | 138篇 |
1986年 | 143篇 |
1985年 | 148篇 |
1984年 | 117篇 |
1983年 | 97篇 |
1982年 | 101篇 |
1981年 | 99篇 |
1980年 | 84篇 |
1979年 | 78篇 |
1978年 | 72篇 |
1977年 | 65篇 |
1976年 | 51篇 |
1975年 | 47篇 |
1974年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Lettilia Xhakaza Zainonesa Abrahams-October Mohammedmekin Mohammedseid Mohammednur Brendon Pearce Oladele Vincent Adeniyi Rabia Johnson Mongi Benjeddou 《African health sciences》2020,20(3):1344
BackgroundRecently, developing countries have shown a dramatic increase in non-communicable diseases (NCDs). The burden of NCDs in South Africa has increased over the past years resulting in an estimated 37% of all- cause mortality and 16% of disability-adjusted life years. Currently, diabetes mellitus (DM) and hypertension (HTN) are the two most prevalent NCDs associated with the rapid increase in mortality.ObjectiveTo demonstrate the socio-demographic and modifiable risk factors of diabetes mellitus (DM) and hypertension (HTN) among South African adults.MethodsA cross-sectional analytical study was conducted in the Cecilia Makiwane Hospital serving the residents of Mdantsane. Relevant socio-demographic data, anthropometric measurements, triplicate blood pressure, fasting blood glucose and lipogram analysis were obtained from 265 outpatients.ResultsMultivariate anlysis shows that; salt intake, smoking, elevated triglycerides and decreased high-density lipoprotein levels were significantly associated with DM with adjusted odds ratio of 0.18 (p=0.002), 0.26 (p=0.048), 2.19 (p=0.006) and 0.38 (p=0.001), respectively. Overweight and obesity were significantly associated with hypertension with odds ratio of 0.03 (p=0.01) and 0.06 (p=0.006), respectively.ConclusionThe burden of DM and HTN on society can be drastically reduced with simple lifestyle changes, development of preventative strategies, large-scale screening and better disease management in South Africa. 相似文献
992.
Pascale Bémer Chloé Plouzeau Didier Tande Julie Léger Bruno Giraudeau Anne Sophie Valentin Anne Jolivet-Gougeon Pascal Vincent Stéphane Corvec Sophie Gibaud Marie Emmanuelle Juvin Genevieve Héry-Arnaud Carole Lemarié Marie Kempf Laurent Bret Roland Quentin Carine Coffre Gonzague de Pinieux Louis Bernard Christophe Burucoa 《Journal of clinical microbiology》2014,52(10):3583-3589
There is no standard method for the diagnosis of prosthetic joint infection (PJI). The contribution of 16S rRNA gene PCR sequencing on a routine basis remains to be defined. We performed a prospective multicenter study to assess the contributions of 16S rRNA gene assays in PJI diagnosis. Over a 2-year period, all patients suspected to have PJIs and a few uninfected patients undergoing primary arthroplasty (control group) were included. Five perioperative samples per patient were collected for culture and 16S rRNA gene PCR sequencing and one for histological examination. Three multicenter quality control assays were performed with both DNA extracts and crushed samples. The diagnosis of PJI was based on clinical, bacteriological, and histological criteria, according to Infectious Diseases Society of America guidelines. A molecular diagnosis was modeled on the bacteriological criterion (≥1 positive sample for strict pathogens and ≥2 for commensal skin flora). Molecular data were analyzed according to the diagnosis of PJI. Between December 2010 and March 2012, 264 suspected cases of PJI and 35 control cases were included. PJI was confirmed in 215/264 suspected cases, 192 (89%) with a bacteriological criterion. The PJIs were monomicrobial (163 cases [85%]; staphylococci, n = 108; streptococci, n = 22; Gram-negative bacilli, n = 16; anaerobes, n = 13; others, n = 4) or polymicrobial (29 cases [15%]). The molecular diagnosis was positive in 151/215 confirmed cases of PJI (143 cases with bacteriological PJI documentation and 8 treated cases without bacteriological documentation) and in 2/49 cases without confirmed PJI (sensitivity, 73.3%; specificity, 95.5%). The 16S rRNA gene PCR assay showed a lack of sensitivity in the diagnosis of PJI on a multicenter routine basis. 相似文献
993.
Liver transplantation is the ultimate treatment for severe hepatic failure to date. However, the limited supply of donor organs has severely hampered this treatment. So far, great potentials of using mesenchymal stem cells (MSCs) to replenish the hepatic cell population have been shown; nevertheless, there still is a lack of an optimal three-dimensional scaffold for generation of well-transplantable hepatic tissues. In this study, we utilized a cryo-chemical decellularization method which combines physical and chemical approach to generate acellular liver scaffolds (ALS) from the whole liver. The produced ALS provides a biomimetic three-dimensional environment to support hepatic differentiation of MSCs, evidenced by expression of hepatic-associated genes and marker protein, glycogen storage, albumin secretion, and urea production. It is also found that hepatic differentiation of MSCs within the ALS is much more efficient than two-dimensional culture in vitro. Importantly, the hepatic-like tissues (HLT) generated by repopulating ALS with MSCs are able to act as functional grafts and rescue lethal hepatic failure after transplantation in vivo. In summary, the cryo-chemical method used in this study is suitable for decellularization of liver and create acellular scaffolds that can support hepatic differentiation of MSCs and be used to fabricate functional tissue-engineered liver constructs. 相似文献
994.
Vivian K. Lee Diana Y. Kim Haygan Ngo Young Lee Lan Seo Seung-Schik Yoo Peter A. Vincent Guohao Dai 《Biomaterials》2014
We developed a methodology using 3D bio-printing technology to create a functional in vitro vascular channel with perfused open lumen using only cells and biological matrices. The fabricated vasculature has a tight, confluent endothelium lining, presenting barrier function for both plasma protein and high-molecular weight dextran molecule. The fluidic vascular channel is capable of supporting the viability of tissue up to 5 mm in distance at 5 million cells/mL density under the physiological flow condition. In static-cultured vascular channels, active angiogenic sprouting from the vessel surface was observed whereas physiological flow strongly suppressed this process. Gene expression analysis was reported in this study to show the potential of this vessel model in vascular biology research. The methods have great potential in vascularized tissue fabrication using 3D bio-printing technology as the vascular channel is simultaneously created while cells and matrix are printed around the channel in desired 3D patterns. It can also serve as a unique experimental tool for investigating fundamental mechanisms of vascular remodeling with extracellular matrix and maturation process under 3D flow condition. 相似文献
995.
996.
Comparison of EBV DNA viral load in whole blood,plasma, B‐cells and B‐cell culture supernatant
下载免费PDF全文
![点击此处可从《Journal of medical virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
997.
Patricia Facchinetti Emilie Dorard Vincent Contremoulins Marie-Claude Gaillard Nicole Déglon Véronique Sazdovitch Chantal Guihenneuc-Jouyaux Emmanuel Brouillet Charles Duyckaerts Bernadette Allinquant 《Neurobiology of aging》2014
Caspase cleaved amyloid precursor protein (APPcc) and SET are increased and mislocalized in the neuronal cytoplasm in Alzheimer Disease (AD) brains. Translocated SET to the cytoplasm can induce tau hyperphosphorylation. To elucidate the putative relationships between mislocalized APPcc and SET, we studied their level and distribution in the hippocampus of 5 controls, 3 Down syndrome and 10 Alzheimer patients. In Down syndrome and Alzheimer patients, APPcc and SET levels were increased in CA1 and the frequency of both localizations in the neuronal cytoplasm was high in CA1, and low in CA4. As the increase of APPcc is already present at early stages of AD, we overexpressed APPcc in CA1 and the dentate gyrus neurons of adult mice with a lentiviral construct. APPcc overexpression in CA1 and not in the dentate gyrus induced endogenous SET translocation and tau hyperphosphorylation. These data suggest that increase in APPcc in CA1 neurons could be an early event leading to the translocation of SET and the progression of AD through tau hyperphosphorylation. 相似文献
998.
Beth H. Vogel Vincent Bonagura Geoffrey A. Weinberg Mark Ballow Jason Isabelle Lisa DiAntonio April Parker Allison Young Charlotte Cunningham-Rundles Chin-To Fong Jocelyn Celestin Heather Lehman Arye Rubinstein Subhadra Siegel Leonard Weiner Carlos Saavedra-Matiz Denise M. Kay Michele Caggana 《Journal of clinical immunology》2014,34(3):289-303
Purpose
To describe the process and assess outcomes for the first 2 years of newborn screening for severe combined immunodeficiency (SCID NBS) in New York State (NYS).Methods
The NYS algorithm utilizes a first-tier molecular screen for TRECs (T-cell receptor excision circles), the absence of which is indicative of increased risk of immunodeficiency.Results
During the first 2 years, 485,912 infants were screened for SCID. Repeat specimens were requested from 561 premature and 746 non-premature infants with low or borderline TRECs. A total of 531 infants were referred for diagnostic evaluation leading to identification of 10 infants with SCID and 87 with a clinically significant non-SCID abnormality based on flow cytometry or CBC results (positive predictive value 20.3 %). Nine infants were diagnosed with typical SCID and one with leaky SCID. SCID diagnoses included two patients with adenosine deaminase deficiency, three patients with typical and one with leaky IL2RG-related SCID, one patient with IL7Rα-related SCID, and three cases of typical SCID, etiology unknown. TRECs were undetectable in eight of the nine babies with typical SCID. Infants with other non-SCID conditions included 27 patients with a syndrome that included T-cell impairment, 18 of which had DiGeorge syndrome. Seventeen infants had T-cell impairment secondary to another clinically significant condition, and 13 were classified as ‘other’. Among 30 infants classified as idiopathic T-cell lymphopenia, 11 have since resolved, and the remainder continues to be followed. One infant with undetectable TRECs had normal follow-up studies. Molecular studies revealed the presence of two changes in the infant’s DNA.Conclusions
Overall, ten infants with SCID were identified during the first 2 years of screening in NYS, yielding an incidence of approximately 1 in 48,500 live births, which is consistent with the incidence observed by other states screening for SCID. The incidence of any clinically significant laboratory abnormality was approximately 1 in 5,000; both estimates are higher than estimates prior to the onset of newborn screening for SCID. Improvements to the NYS algorithm included the addition of a borderline category that reduced the proportion of infants referred for flow cytometric analysis, without decreasing sensitivity. We identified a large number of infants with abnormal TRECs and subsequent idiopathic T-cell lymphopenia. Long-term follow-up studies are needed to determine the prognosis and optimal treatment for this group of patients, some of whom may present with previously unrecognized, transient lymphopenia of infancy. 相似文献999.
Jacques Abboud François Nougarou Isabelle Pagé Vincent Cantin Daniel Massicotte Martin Descarreaux 《European journal of applied physiology》2014,114(12):2645-2654
Purpose
To identify and characterize trunk neuromuscular adaptations during muscle fatigue in patients with chronic low back pain (LBP) and healthy participants.Methods
Forty-six patients with non-specific chronic LBP and 23 healthy controls were asked to perform a trunk muscles fatigue protocol. Surface electromyography was recorded using two adhesive matrix of 64 electrodes applied bilaterally over the erector spinae. Pain score, kinesiophobia and physical disability were analyzed through different questionnaires. To characterize motor variability, dispersion of muscular activity center of gravity was computed. Motor variability between groups was compared using repeated-measures analyses of variance.Results
Score of disability and kinesiophobia were significantly higher in patients with LBP. Results indicated a significant group effect characterized by an increased motor variability in the healthy group through the entire fatigue task on the left (p = 0.003) and right side (p = 0.048). Interestingly, increasing muscle fatigue led to increased motor variability in both groups (on both sides (p < 0.001) but with a greater increase in the healthy group.Conclusion
Muscle recruitment is altered in patients with chronic LBP in the presence of muscle fatigue. Consequently, these patients exhibit changes in muscle recruitment pattern and intensity (lower levels of motor variability) during sustained isometric contraction that may be attributed to variation in the control of motor units within and between muscles. However, patients with LBP are able to increase their motor variability over time but with a lower increase compared to healthy participants. 相似文献1000.
Irja Lutsar Corine Chazallon Francesca Ippolita Calò Carducci Ursula Trafojer Ben Abdelkader Vincent Meiffredy de Cabre Susanna Esposito Carlo Giaquinto Paul T. Heath Mari-Liis Ilmoja Aspasia Katragkou Carine Lascoux Tuuli Metsvaht George Mitsiakos Emmanuelle Netzer Lorenza Pugni Emmanuel Roilides Yacine Saidi Kosmas Sarafidis Mike Sharland Vytautas Usonis Jean-Pierre Aboulker 《European journal of pediatrics》2014,173(8):997-1004
Late onset neonatal sepsis (LOS) has a high mortality and the optimal management is poorly defined. We aimed to evaluate new expert panel-derived criteria to define LOS and characterize the current management and antibiotic susceptibility of LOS-causing organisms in Europe. A prospective observational study enrolled infants aged 4 to 90 days in five European countries. Clinical and laboratory findings as well as empiric treatment were recorded and patients were followed until the end of antibiotic therapy. Failure was defined as a change of primary antibiotic, no resolution of clinical signs, appearance of new signs/pathogens or death. Antibiotic therapy was considered appropriate if the organism was susceptible to at least one empiric antibiotic. 113 infants (median age 14 days, 62 % ≤1500 g) were recruited; 61 % were culture proven cases (28 CoNS, 24 Enterobacteriaceae, 11 other Gram-positives and 6 Gram-negative non-fermentative organisms). The predictive value of the expert-panel criteria to identify patients with a culture proven LOS was 61 % (95 % CI 52 % to 70 %). Around one third of Enterobacteriaceae were resistant to ampicillin + or cefotaxime + gentamicin but only 10 % to meropenem. Empiric treatment contained a total of 43 different antibiotic regimens. All-cause mortality was 8 % with an additional 45 % classified as failure of empiric therapy, mainly due to change of primary antibiotics (42/60). Conclusions: The expert panel—derived diagnostic criteria performed well identifying a high rate of culture proven sepsis. Current management of LOS in Europe is extremely variable suggesting an urgent need of evidence-based guidelines. 相似文献