全文获取类型
收费全文 | 303篇 |
免费 | 24篇 |
国内免费 | 31篇 |
专业分类
儿科学 | 30篇 |
妇产科学 | 4篇 |
基础医学 | 21篇 |
口腔科学 | 13篇 |
临床医学 | 50篇 |
内科学 | 63篇 |
皮肤病学 | 1篇 |
神经病学 | 15篇 |
特种医学 | 55篇 |
外科学 | 9篇 |
综合类 | 21篇 |
预防医学 | 16篇 |
眼科学 | 4篇 |
药学 | 43篇 |
中国医学 | 1篇 |
肿瘤学 | 12篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 9篇 |
2013年 | 12篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2010年 | 9篇 |
2009年 | 15篇 |
2008年 | 11篇 |
2007年 | 20篇 |
2006年 | 10篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 17篇 |
1996年 | 15篇 |
1995年 | 13篇 |
1994年 | 19篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 11篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 11篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 1篇 |
排序方式: 共有358条查询结果,搜索用时 11 毫秒
61.
A A Adesina R Kashap L S Salimonu 《Nutrition (Burbank, Los Angeles County, Calif.)》1990,6(5):377-381
Primary and secondary immune responses to low doses of sheep red blood cells (SRBC) were investigated in well-fed first-degree offspring of three groups of protein-deficient mice (PD) and in well-fed first-degree offspring of well-fed mice (ND). The offspring of malnourished males and malnourished females had the highest level of primary anti-SRBC antibodies, followed by the offspring of well-fed males and malnourished females, which also had a significantly higher primary anti-SRBC antibody titer than the ND mice. The antibody titer to SRBC of the offspring of malnourished males and well-fed females was, however, not significantly different from that of the ND mice. Following the administration of Plasmodium yoelii, the offspring of the malnourished males and females had the highest mean percentage of parasitemia, followed by the offspring of the well-fed males and malnourished females. The offspring of malnourished males and well-fed females had a mean percentage of parasitemia very close to that of the control group. The study confirms that impaired immunocompetence caused by intrauterine protein depletion may be so permanent as to affect the next generation as well, thereby giving an immunologic profile similar to that of the undernourished mothers. 相似文献
62.
63.
64.
65.
L Moreno SK McMaster T Gatheral LK Bailey LS Harrington N Cartwright PCJ Armstrong TD Warner M Paul-Clark JA Mitchell 《British journal of pharmacology》2010,160(8):1997-2007
Background and purpose:
Gram-negative bacteria contain ligands for Toll-like receptor (TLR) 4 and nucleotide oligomerization domain (NOD) 1 receptors. Lipopolysaccharide (LPS) activates TLR4, while peptidoglycan products activate NOD1. Activation of NOD1 by the specific agonist FK565 results in a profound vascular dysfunction and experimental shock in vivo.Experimental approach:
Here, we have analysed a number of pharmacological inhibitors to characterize the role of key signalling pathways in the induction of NOS2 following TLR4 or NOD1 activation.Key results:
Vascular smooth muscle (VSM) cells expressed NOD1 mRNA and protein, and, after challenge with Escherichia coli or FK565, NOS2 protein and activity were induced. Macrophages had negligible levels of NOD1 and were unaffected by FK565, but responded to E. coli and LPS by releasing increased NO and expression of NOS2 protein. Classic pharmacological inhibitors for NF-κB (SC-514) and mitogen-activated protein kinase (SB203580, PD98059) signalling pathways inhibited responses in both cell types regardless of agonist. While TLR4-mediated responses in macrophages were specifically inhibited by the pan-caspase inhibitor z-VAD-fmk and the PKC inhibitor Gö6976, NOD1-mediated responses in VSM cells were inhibited by the Rip2 inhibitor PP2.Conclusions and implications:
Our findings suggest a selective role for NOD1 in VSM cells, and highlight NOD1 as a potential novel therapeutic target for the treatment of vascular inflammation. 相似文献66.
Jennifer LS Lofgren Michael Esmail Melissa Mobley Amanda McCabe Nancy S Taylor Zeli Shen Susan Erdman Christine Hewes Mark T Whary James G Fox 《Journal of the American Association for Laboratory Animal Science》2012,51(4):436-442
Most academic research colonies of mice are endemically infected with enterohepatic Helicobacter spp. (EHS). We evaluated EHS prevalence in surveillance mice before and after a 10-y period of requiring that imported mice be free of EHS by embryo transfer rederivation or purchase from approved vendors. In 2009, composite fecal samples from CD1 surveillance mice representing colony health in 57 rooms located in 6 facilities were evaluated for EHS infection by using PCR assays. Fecal samples were screened with primers designed to detect all known EHS, and positive samples were further assayed by using primers specific for H. hepaticus, H. bilis, H. rodentium, and H. typhlonicus. Most EHS were detected in surveillance mice within the first month of dirty bedding exposure, with prevalence ranging from 0% to 64% as monoinfections or, more commonly, infections with multiple EHS. Compared with 1999 prevalence data, EHS remained endemic in colonies importing the lowest number of EHS-free mice. EHS were absent or the prevalence was greatly reduced in colonies receiving the highest percentage of EHS-free mice. This study demonstrates that the management decision to require exclusive importation of EHS-free mice reduced EHS prevalence on an institutional scale without intensive labor and expense associated with other techniques or interference with research objectives.Abbreviation: EHS, enterohepatic Helicobacter spp.; ET, embryo transfer; Hb, H. bilis; Hh, H. hepaticus; Hm, H. mastomyrinus; Hr, H. rodentium; Ht, H. typhlonicusEnterohepatic Helicobacter spp. (EHS) infections are endemic in the majority of research mouse colonies. In 2007, 84% of mice shipped from academic institutions worldwide for embryo transfer (ET) rederivation at our institution were PCR-positive for EHS. H. hepaticus (Hh) was detected in 64% of the mouse shipments either as a monoinfection or in combination with other EHS including H. bilis (Hb), H. rodentium (Hr), H. typhlonicus (Ht), and H. mastomyrinus (Hm).30 Although EHS generally cause subclinical infection in immunocompetent mice, opportunistic infections have the potential to confound experimental data in mouse models.9,17,34 Importantly, chronic EHS infection in immunodeficient and select inbred strains of mice can induce liver10 and lower bowel carcinoma,13 typhlocolitis, and rectal prolapse,16,21,28 and reduce reproductive performance.25 In addition, EHS-induced inflammatory responses may alter host immune responses to unrelated experimental infections (for example, promoting elevated systemic IFNγ responses).3,20Key challenges to eradication of EHS from rodent colonies are determining infection status, eliminating endemic infections, and instituting management practices that prevent reinfection. EHS are disseminated through fecal–oral transmission within a colony and are transmissible to surveillance mice through dirty-bedding exposure.1,19,24,32 For routine surveillance, PCR assay of feces or cecal mucosal scrapings for genus-specific Helicobacter 16S rRNA genes is the most efficient means of detecting EHS infection, with speciation (if desired) of positive results by culture, restriction fragment length polymorphism analysis, species-specific PCR, or sequence analysis.34 In 1999, as determined by species-specific PCR assays of cecal scrapings from 59 surveillance mice exposed to dirty bedding from colony mice in 26 rooms representing 4 mouse facilities, EHS were endemic on our campus, with prevalence in surveillance mice of 41% for Hh, 82% for Hr, and 6% for Hb.32 Husbandry practices used to minimize cage-to-cage transmission of EHS included microisolation caging, sanitized forceps to transfer mice, and a cage change order from known Helicobacter-free mice to mice of unknown or known EHS infection status (that is, clean to dirty traffic flow of personnel and equipment).32 Although EHS eradication potentially could be accomplished campus-wide by using labor-intensive antibiotics7,15 and cross-fostering,4,29,31 we hypothesized that a more cost-effective approach, without confounding experimental data, would be to restrict importation of mice to EHS-free sources. Vendors were screened to establish that production colonies were SPF for EHS, and a new requirement was instituted for embryo transfer (ET) rederivation of mice obtained from random sources, typically other academic institutions, replacing traditional quarantine practices. This study used PCR data from 1999 and 2009 to evaluate the success of this approach, which was defined as a marked decrease in the prevalence of EHS infection over time. 相似文献
67.
68.
H Calkins P Yong JM Miller B Olshansky M Carlson JP Saul SK Huang LB Liem LS Klein SA Moser DA Bloch P Gillette E Prystowsky 《Circulation》1999,99(2):262-270
BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of a temperature-controlled radiofrequency catheter ablation system. METHODS AND RESULTS: The patient population included 1050 patients who had undergone ablation of atrioventricular nodal reentrant tachycardia (AVNRT), an accessory pathway (AP), or the atrioventricular junction (AVJ). Ablation was successful in 996 patients. The probability of success was highest among patients who had undergone ablation of the AVJ, lowest in patients who had undergone ablation of an AP, and in between for patients who had undergone ablation of AVNRT. A major complication occurred in 32 patients. Four variables predicted ablation success (AVJ, AVNRT, or left free wall AP ablation and an experienced center). Four factors predicted arrhythmia recurrence (right free wall, posteroseptal, septal, and multiple APs). Two variables predicted development of a complication (structural heart disease and the presence of multiple targets), and 3 variables predicted an increased risk of death (heart disease, lower ejection fraction, and AVJ ablation). CONCLUSIONS: These findings may serve as a guide to clinicians considering therapeutic options in patients who are candidates for ablation. 相似文献
69.
B McKenzie-Green LS Giddings L Buttle K Tahana 《International journal of dental hygiene》2009,7(1):31-38
Abstract: Objectives: Little is known about older persons’ perceptions of oral health and oral health care. The purpose of this study was to explore the viewpoint of older adults’ regarding their oral health care practices. Methods: A qualitative interpretive methodology was employed comprising three analytic levels: coding of data into concepts, analysis of concepts into themes, followed by an in‐depth analysis of relationships within concepts and between themes. In‐depth individual interviews were conducted with 19 participants aged 65 to 87 years. Results: Older people’s decision to access oral health care involves complex and personally meaningful strategies. A dental visit surfaces hopes and fears based on past and present experiences. Mouth and teeth are not merely objects of dental care; they represent a person’s social and relational self. Age‐related changes challenge the relational self as represented in societal ideal images of youth and perfection (the perfect smile). This study highlights older peoples’ resilience and determination when faced with the dilemmas in accessing oral health care – it costs, personally as well as financially. Contrary to the assumption that older peoples’ oral health status is related to neglect, rather for many, it is the result of the intersection of their history with technological advances. Conclusions: These findings challenge oral health care practitioners to be sensitive to the contexts affecting their older client’s oral health care status. They do not ‘just go’ to the dentist; they bring with them their past dental experiences and their hopes for the future. It matters how one is treated at this vulnerable time. 相似文献
70.
M Hill K Finning P Martin J Hogg C Meaney G Norbury G Daniels LS Chitty 《Clinical genetics》2011,80(1):68-75
Hill M, Finning K, Martin P, Hogg J, Meaney C, Norbury G, Daniels G, Chitty LS. Non‐invasive prenatal determination of fetal sex: translating research into clinical practice. The effectiveness and clinical utility of non‐invasive prenatal diagnosis (NIPD) for fetal sex determination using cell‐free fetal DNA (cffDNA) was assessed by undertaking a prospective national audit of UK testing. NIPD was performed using real‐time polymerase chain reaction analysis of the DYS14 or SRY gene in cffDNA extracted from maternal plasma. All cases referred for fetal sex determination from 1 April 2006 to 31 March 2009 were ascertained from two laboratories offering the test. Fetal gender determined by NIPD was compared with that based on ultrasound, invasive test or phenotype at birth. Indication and rate of invasive testing was ascertained. In the first year, results were issued in 150/161 pregnancies tested. Of the 135 with outcome data, results were concordant in 130/135 [96.3% (95% CI 91.6–98.8%)]. Reporting criteria were changed and in the subsequent 511 pregnancies the concordancy rate increased to 401/403 [99.5% (95% CI 98.2–99.9%)]. Over the 3 years only 32.9% (174/528) underwent invasive testing. NIPD for fetal sex determination using cffDNA is highly accurate when performed in National Health Service laboratories if stringent reporting criteria are applied. Parents should be advised of the small risk of discordant results and possible need for repeat testing to resolve inconclusive results. 相似文献