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81.
Yang Li Zhenzhen Shi Isabella Radauer-Preiml Ancuela Andosch Eudald Casals Ursula Luetz-Meindl 《Nanotoxicology》2017,11(9-10):1157-1175
Nanoparticles (NPs) are easily contaminated by bacterial endotoxin (lipopolysaccharide [LPS]). The presence of LPS can be responsible for many immune/inflammatory effects attributed to NPs. In this study, we examined the effects of LPS adsorption on the NP surface on the formation of a biocorona in biological fluids and on the subsequent inflammation-inducing activity of NPs. Different gold (Au) NPs with sizes ranging from 10 to 80?nm and with different surface functionalization (sodium citrate, lipoic acid, and branched polyethyleneimine (BPEI), or polyethylene glycol (PEG)) were exposed to E. coli LPS under different conditions. The binding capacity of LPS to the surface of AuNPs was dose- and time-dependent. LPS attached to sodium citrate and lipoic acid coatings, but did not adhere to BPEI- or PEG-coated NPs. By computational simulation, the binding of LPS to AuNPs seems to follow the Langmuir absorption isotherm. The presence of LPS on AuNP surface interfered and caused a decrease in the formation of the expected biomolecular corona upon incubation in human plasma. LPS-coated AuNPs, but not the LPS-free NPs, induced significant inflammatory responses in vitro. Notably, while free LPS did also induce an anti-inflammatory response, LPS bound to NPs appeared unable to do so. In conclusion, the unintentional adsorption of LPS onto the NP surface can affect the biocorona formation and the inflammatory properties of NPs. Thus, for an accurate interpretation of NP interactions with cells, it is extremely important to be able to distinguish the intrinsic NP biological effects from those caused by biologically active contaminants such as endotoxin. 相似文献
82.
Toll-like receptor interactions: tolerance of MyD88-dependent cytokines but enhancement of MyD88-independent interferon-beta production 下载免费PDF全文
Broad A Kirby JA Jones DE;Applied Immunology Transplantation Research Group 《Immunology》2007,120(1):103-111
Toll-like receptors (TLRs) signal through two main pathways: a myeloid differentiation factor (MyD)88-dependent pathway that acts via nuclear factor kappaB (NF-kappaB) to induce proinflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha) and a MyD88-independent pathway that acts via type I interferons to increase the expression of interferon-inducible genes. Repeated signalling through TLR4 and a number of other TLRs has been reported to result in a reduction in the subsequent proinflammatory cytokine response, a phenomenon known as TLR tolerance. In this study we have shown that, whilst NF-kappaB activation and production of TNF-alpha and interleukin-12 by murine RAW264.7 and J774.2 cells in response to stimulation by TLR4, -5, -7 or -9, was reduced by prior stimulation with TLR4, -5, -7 or -9 ligands, the primary stimulation of TLR3, which does not use the MyD88 pathway, did not reduce the TNF-alpha or interleukin-12 responses to subsequent TLR stimulation. The response to TLR3 stimulation was not diminished by prior TLR ligand exposure. Furthermore, the production of interferon-beta (IFN-beta) following stimulation of TLR3 or -4, which is MyD88-independent, was increased by prior activation of TLR4, -5, -7 or -9. In contrast, TLR9 ligand-induced IFN-beta production, which is MyD88-dependent, was tolerized by prior TLR stimulation. These results are consistent with differential regulation of MyD88-dependent and MyD88-independent cytokine production following serial activation of TLRs. 相似文献
83.
Francés R González-Navajas JM Zapater P Muñoz C Caño R Pascual S Márquez D Santana F Pérez-Mateo M Such J 《Journal of clinical immunology》2007,27(4):438-444
Translocation of intestinal bacteria to ascitic fluid is, probably, the first step in the development of spontaneous bacterial peritonitis in patients with cirrhosis. Proteins of the complement system are soluble mediators implicated in the host immune response to bacterial infections and its activation has been traditionally considered to be an endotoxin-induced phenomenon. The aim of this study was to compare the modulation of these proteins in response to the presence of bacterial DNA and/or endotoxin in patients with advanced cirrhosis and ascites in different clinical conditions. Groups I and II consisted of patients without/with bacterial DNA. Group III included patients with spontaneous bacterial peritonitis and Group IV with patients receiving norfloxacin as secondary long-term prophylaxis of spontaneous bacterial peritonitis. Serum and ascitic fluid levels of endotoxin and truncated residues of the complement system were measured by ELISA. The complement system is triggered in response to bacterial DNA, as evidenced by significantly increased levels of C3b, membrane attack complex, and C5a in patients from Groups II and III compared with patients without bacterial DNA (Group I) and those receiving norfloxacin (Group IV). Gram classification did not further differentiate the immune response between patients within groups II and III, even though endotoxin levels were, as expected, significantly higher in patients with bacterial DNA from gram-negative microorganisms. The complement protein activation observed in patients with bacterial DNA in blood and ascitic fluid is indistinguishable from that observed in patients with spontaneous bacterial peritonitis and may occur in an endotoxin-independent manner. 相似文献
84.
Karadag B Ege MJ Scheynius A Waser M Schram-Bijkerk D van Hage M Pershagen G Brunekreef B Riedler J Braun-Fahrländer C von Mutius E;PARSIFAL Study Team 《Allergy》2007,62(12):1387-1393
BACKGROUND: There is still uncertainty about the determinants of atopic eczema (AE). To explain the heterogeneity of the disease, different phenotypes of AE have been suggested. METHODS: The cross-sectional PARSIFAL study included 14 893 school-age children of farmers or children attending Steiner schools and their respective reference groups. A detailed questionnaire was completed, and house dust was collected for the measurement of endotoxin and glucans. Atopic sensitization was defined by allergen-specific IgE levels in the serum. RESULTS: In multivariate analyses, helping with haying was the only variable related to a farming environment having a consistent inverse association with both current symptoms and a doctor's diagnosis of AE [aOR = 0.65 (95% CI: 0.46-0.93) and 0.73 (0.51-1.05)], respectively. Severe lower respiratory tract infections (LRTI) in the first 2 years of life and usage of antibiotics ever were found to be positively related only to asthma-associated AE, whereas the effect of LRTI on AE without asthma had an opposite effect. Levels of beta(1-->3)-glucans in mattress dust were inversely related to a doctor's diagnosis of asthma-associated AE [aOR = 0.75 (0.57-0.98)], and endotoxin levels to current symptoms of asthma-associated AE [aOR = 0.73 (0.57-0.94)]. CONCLUSIONS: The analyses of the PARSIFAL study revealed two different phenotypes of AE, depending on the association with asthma and wheezing ever. With regard to the hygiene hypothesis, help with haying, exposure to beta(1-->3)-glucans and endotoxin were found to be inversely associated with the AE phenotype associated with asthma and wheezing. 相似文献
85.
Margaret E. Davidson Joshua Schaeffer Maggie L. Clark Sheryl Magzamen Elizabeth J. Brooks Thomas J. Keefe 《Journal of occupational and environmental hygiene》2018,15(3):182-193
Dairy workers experience a high degree of bioaerosol exposure, composed of an array of biological and chemical constituents, which have been tied to adverse health effects. A better understanding of the variation in the magnitude and composition of exposures by task is needed to inform worker protection strategies. To characterize the levels and types of exposures, 115 dairy workers grouped into three task categories on nine farms in the high plains Western United States underwent personal monitoring for inhalable dust, endotoxin, 3-hydroxy fatty acids (3-OHFA), muramic acid, ergosterol, and ammonia through one work shift. Eighty-nine percent of dairy workers were exposed to endotoxin at concentrations exceeding the recommended exposure guidelines (adjusted for a long work shift). The proportion of workers with exposures exceeding recommended guidelines was lower for inhalable dust (12%), and ammonia (1%). Ergosterol exposures were only measurable on 28% of samples, primarily among medical workers and feed handlers. Milking parlor workers were exposed to significantly higher inhalable dust, endotoxin, 3-OHFA, ammonia, and muramic acid concentrations compared to workers performing other tasks. Development of large modern dairies has successfully made progress in reducing worker exposures and lung disease prevalence. However, exposure to endotoxin, dust, and ammonia continues to present a significant risk to worker health on North American dairies, especially for workers in milking parlors. This study was among the first to concurrently evaluate occupational exposure to assayable endotoxin (lipid A), 3-hydroxy fatty acids or 3-OHFA (a chemical measure of cell bound and noncell-bound endotoxins), muramic acid, ergosterol, and ammonia among workers on Western U.S. dairies. There remains a need for cost-effective, culturally acceptable intervention strategies integrated in OHS Risk Management and production systems to further optimize worker health and farm productivity. 相似文献
86.
摘 要 目的:建立原料药HSSYO 001 3S细菌内毒素检查方法。方法: 以二甲亚砜(DMSO)溶解HSSYO 001 3S,用适量细菌内毒素检查用水(BET水)稀释后,离心取上清液,按中国药典2015年版四部通则11431检查凝胶法,对HSSYO 001 3S进行细菌内毒素检查的方法学研究。结果:HSSYO 001 3S加助溶剂并以BET水稀释至1 mg·m-1 ,经离心后取上清液稀释4倍及以上时对鲎试剂凝集反应无干扰作用。结论:HSSYO 001 3S可采用细菌内毒素检查法控制其质量。 相似文献
87.
目的:注射用磷酸特地唑胺用于特定的敏感细菌引起的成人急性细菌性皮肤和皮肤结构感染,于2014年6月20日,被美国FDA批准磷酸特地唑胺上市,临床研究也进入了临床II期,用于严重革兰氏阳性菌感染的治疗。该药尚未在中国上市。未被中国药典2015年版收录,没有与之相关的质量标准,所以需要尽快制定药品的检验标准,已完善医药市场对药物的质量要求与监管。方法:参照中国药典2015年版二部,拟定的质量标准并对细菌内毒素检查的方法学进行了验证。结果:拟定本品的细菌内毒素限值为1.5EU/mg,当采用灵敏度为0.5EU/ml的鲎试剂,样品浓度为含磷酸特地唑胺4mg/ml时,对内毒素与鲎试剂的反应无干扰。结论:当采用两个鲎试剂生产厂家的试剂对样品进行干扰试验,灵敏度为0.5EU/ml,样品浓度为含磷酸特地唑胺4mg/ml时,对内毒素与鲎试剂的反应无干扰。此限值为可靠限值。此浓度为本品的最大无干扰浓度。 相似文献
88.
89.
目的:建立注射用尤瑞克林细菌内毒素的检查方法。方法:按照2010年版《中国药典》(二部)附录细菌内毒素检查法的要求,用2个厂家的鲎试剂对3个批号的注射用尤瑞克林进行干扰试验和细菌内毒素检查。结果:样品的浓度≤0.000 75 PNA/ml时对细菌内毒素检查无干扰。结论:细菌内毒素检查法可以用于注射用尤瑞克林细菌内毒素的限量检查。 相似文献
90.
目的:建立注射用兰索拉唑的细菌内毒素检查法。方法:按照2010年版《中国药典》(二部)附录细菌内毒素检查法,采用2个厂家的鲎试剂对5个厂家的5批样品,通过预干扰和干扰试验确定样品最大无干扰质量浓度,并进行细菌内毒素检查。结果:将供试品溶液稀释到质量浓度为0.1 mg/ml时,不干扰细菌内毒素试验,其细菌内毒素限值为5 EU/mg。结论:采用细菌内毒素检查法检查注射用兰索拉唑中的细菌内毒素方法可行。 相似文献