全文获取类型
收费全文 | 211篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 5篇 |
妇产科学 | 10篇 |
基础医学 | 37篇 |
口腔科学 | 19篇 |
临床医学 | 13篇 |
内科学 | 38篇 |
皮肤病学 | 1篇 |
神经病学 | 44篇 |
特种医学 | 3篇 |
外科学 | 11篇 |
综合类 | 11篇 |
一般理论 | 3篇 |
预防医学 | 12篇 |
眼科学 | 2篇 |
药学 | 10篇 |
中国医学 | 1篇 |
肿瘤学 | 11篇 |
出版年
2023年 | 3篇 |
2021年 | 6篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 3篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 18篇 |
2004年 | 8篇 |
2003年 | 13篇 |
2002年 | 4篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1983年 | 4篇 |
1980年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1970年 | 4篇 |
1969年 | 5篇 |
1968年 | 2篇 |
1967年 | 3篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1929年 | 1篇 |
1928年 | 1篇 |
1927年 | 1篇 |
排序方式: 共有232条查询结果,搜索用时 15 毫秒
1.
2.
The Gram-positive bacterium Streptococcus pneumoniae is the leading causative pathogen in community-acquired pneumonia. The ever-increasing frequency of antibiotic-resistant S. pneumoniae strains severely hampers effective treatments. Thus, a better understanding of the mechanisms involved in the pathogenesis of pneumococcal disease is needed; in particular, of the initial interactions that take place between the host and the bacterium. Recognition of pathogens by dendritic cells is one of the most crucial steps in the induction of an immune response. For efficient pathogen recognition, dendritic cells express various kinds of receptors, including the DC-specific C-type lectin DC-SIGN. Pathogens such as Mycobacterium tuberculosis and HIV target DC-SIGN to escape immunity. Here the in vitro binding of DC-SIGN with S. pneumoniae was investigated. DC-SIGN specifically interacts with S. pneumoniae serotype 3 and 14 in contrast to other serotypes such as 19F. While the data described here suggest that DC-SIGN interacts with S. pneumoniae serotype 14 through a ligand expressed by the capsular polysaccharide, the binding to S. pneumoniae serotype 3 appears to depend on an as yet unidentified ligand. Despite the binding capacity of the capsular polysaccharide of S. pneumoniae 14 to DC-SIGN, no immunomodulatory effects on the dendritic cells were observed. The immunological consequences of the serotype-specific capacity to interact with DC-SIGN should be further explored and might result in new insights in the development of new and more potent vaccines. 相似文献
3.
Kenneth Clark Bruce Vendt Kirk Smith John Freymann Justin Kirby Paul Koppel Stephen Moore Stanley Phillips David Maffitt Michael Pringle Lawrence Tarbox Fred Prior 《Journal of digital imaging》2013,26(6):1045-1057
The National Institutes of Health have placed significant emphasis on sharing of research data to support secondary research. Investigators have been encouraged to publish their clinical and imaging data as part of fulfilling their grant obligations. Realizing it was not sufficient to merely ask investigators to publish their collection of imaging and clinical data, the National Cancer Institute (NCI) created the open source National Biomedical Image Archive software package as a mechanism for centralized hosting of cancer related imaging. NCI has contracted with Washington University in Saint Louis to create The Cancer Imaging Archive (TCIA)—an open-source, open-access information resource to support research, development, and educational initiatives utilizing advanced medical imaging of cancer. In its first year of operation, TCIA accumulated 23 collections (3.3 million images). Operating and maintaining a high-availability image archive is a complex challenge involving varied archive-specific resources and driven by the needs of both image submitters and image consumers. Quality archives of any type (traditional library, PubMed, refereed journals) require management and customer service. This paper describes the management tasks and user support model for TCIA. 相似文献
4.
Christine Y. Bakhoum Abby Basalely Robert I. Koppel 《The journal of maternal-fetal & neonatal medicine》2019,32(19):3185-3190
Purpose: Acute kidney injury (AKI) is an independent predictor of morbidity and mortality in critically ill infants and children. AKI develops in an estimated one-third of the neonatal intensive care unit (NICU) population; however, literature on the incidence of AKI in premature infants with a diagnosis of necrotizing enterocolitis (NEC) is limited. The objectives of this study were to describe the incidence of AKI in infants with radiographically confirmed NEC, assess these infants for independent risk factors associated with development of AKI and evaluate if the presence of AKI is associated with increased mortality.Study design: We conducted a retrospective chart review of premature infants, gestational age (GA) 23–34 weeks, who developed modified Bell’s level 2 or 3 NEC while admitted to two tertiary NICUs within our health system between 2010 and 2015. AKI was defined and staged according to modified Kidney Disease: Improving Global Outcomes (KDIGO) criteria.Results: 77 infants with Bell’s level II (63.6%) and III (36.4%) NEC were studied. AKI occurred in 42.9% of infants (Stage 1: 18.2%; Stage 2: 13%; Stage 3: 11.7%). Bell’s Stage III NEC, lower GA, maternal preeclampsia/eclampsia, gentamicin/vancomycin exposure, and empiric antibiotic use were independently associated with AKI. AKI was strongly associated with mortality (HR 20.3 95%CI 2.5–162.8, p?=?.005) in an adjusted Cox model.Conclusions: AKI is common in premature infants who develop NEC. More severe NEC was found to be an independent risk factor for AKI. Additionally, AKI in infants with NEC increases mortality risk significantly. 相似文献
5.
The need to underpin health and education with a firm evidence base is of increasing significance. Systematic review offers an effective approach to critically assessing research in order to understand its overall impact on practice. Based on 5 years' experience undertaking systematic reviews of interprofessional education, this paper offers guidance for researchers and practitioners about to embark upon systematic review work. 相似文献
6.
Seizures in the critically ill: the role of imipenem 总被引:5,自引:0,他引:5
PURPOSE: To determine the risk of seizures in critically ill patients receiving the antibiotic imipenem, a broad-spectrum antibiotic that has been associated with seizures. Reports generally have not considered other contributing factors such as dose, seizure history, and morbidity index of the underlying illness necessitating the antibiotic. METHODS: Charts of all patients in a 450-bed municipal hospital who received imipenem in a 6-month period, as determined by pharmacy records, were reviewed for dosage and duration of imipenem use, occurrence of seizures. and mortality outcome. Attention was paid to demographic features; pattern of seizure occurrence during, before, and after imipenem use; renal function; and correction for dosage based on size. RESULTS: Seventy-five charts were reviewed. Sixty-three patients had no seizures during the hospitalization, four had seizures while receiving imipenem, and eight had seizures during the hospitalization but before or after imipenem use. The incidence of seizures was 4/1,000 patient-days on, and 3.9/1,000 patient-days off imipenem (not significant). The risk of seizure in both groups was considerably higher in those patients with a history of seizures before hospitalization. The presence of other factors that could contribute to increased concentration of imipenem in the brain, such as renal failure or acute stroke, did not contribute to seizure incidence. Metabolic derangement, anoxia, and phenytoin discontinuation did contribute to seizure incidence. CONCLUSIONS: Seizure incidence is increased in all critically ill patients (16% of patients studied), but with no added risk during the period patients received imipenem. Determining the proper dose based on a patient's body mass, correction of dose in the presence of renal failure, and avoidance of excess of 2 g/day of imipenem removes any added risk for seizures from imipenem. Despite experimental data to suggest action of imipenem on the glutamate/N-methyl-d-aspartate receptor, or interference with binding to the gamma-aminobutyric acid receptor, and early clinical studies that warned against its use because of seizure risk, we found that careful use of this antibiotic is safe. 相似文献
7.
8.
Applications of neuroreceptor imaging to psychiatry research 总被引:4,自引:0,他引:4
Over the past two decades, there have been significant advances in the ability to study the neurochemistry of the living brain using neuroreceptor radiotracers with Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) imaging modalities. The greater availability of radiotracers for neurotransmitter synthesis/metabolism, enzymes, transporters and receptors, as well as neuromodulators and second messengers has enabled the evaluation of hypotheses regarding neurotransmitter function and regulation that are generated from basic neuroscience studies in animals, and the investigation of the neurochemical substrates of psychiatric disorders and the mechanism of action of psychotropic medications. This review will focus on the status of radiotracer development, on the clinical and methodological considerations regarding neurochemical brain imaging study design and data interpretation. The applications of neurochemical brain imaging methods to the study of specific psychiatric disorders, including schizophrenia, anxiety disorders, depression and Alzheimer's Disease, will be reviewed and potential future directions of research in these areas identified. Finally, the studies of the neurochemical substrates of personality traits will be reviewed. Thus far, fundamental observations have been made with respect to 1). detecting abnormalities in the availability of neurotransmitter transporter and receptor sites in psychiatric patients; 2). evaluating the relationship of these neurochemical measures to symptomatology; and 3). assessing the magnitude of occupancy of the initial target sites of action of psychotropic medication relative to treatment response and drug concentrations. Further advances in instrumentation and radiotracer chemistry will enable investigators to conduct pre-clinical and clinical mechanistic studies focused on other neurotransmitters and neuromodulators. These data will provide important insights into the neurochemical substrates of treatment response variability in psychiatric disorders that will have important implications for the refinement of pharmacotherapy. 相似文献
9.
Previous in vitro studies have shown that Al(3+) binds to calmodulin, inducing alterations in its capability to interact with target proteins, accompanied by loss of immunological recognition by its conformational specific monoclonal antibody CAM1. In spite of the wealth of data of calmodulin action in vitro, little information is available on the possible involvement of this protein in the pathology typical of Alzheimer's disease. In the present study, we investigated calmodulin immunoreactivity in post-mortem human brains affected by Alzheimer's disease, compared with age-matched control brains. Conformational monoclonal antibodies raised against Ca(2+)-calmodulin, namely CAM1 and CAM4, were used in this study for the characterization of calmodulin. Calmodulin immunorecognition by monoclonal antibody CAM1 was found to be lost in cortical tissue sample from brains affected by Alzheimer's disease. This finding leads to the hypothesis of a new, possibly inactive, conformation of the molecule during the disease. On the other hand, CAM4 immunoreactivity was decreased in neurons of brains affected by Alzheimer's disease. Anti-Al(3+) monoclonal antibodies revealed instead more marked aluminium immunoreactivity in the affected brains compared to normal ones. The loss of CAM1 immunoreactivity and the occurrence of large amounts of aluminium suggest an alteration of the active conformation of calmodulin in disease-affected brains. These alterations could be involved in the development of Alzheimer's disease pathology. 相似文献
10.
Keratinocyte p38δ loss inhibits Ras‐induced tumor formation,while systemic p38δ loss enhances skin inflammation in the early phase of chemical carcinogenesis in mouse skin 下载免费PDF全文