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Lead-exposed workmen and fertility: A cohort study on 354 subjects   总被引:3,自引:0,他引:3  
A cohort study was conducted in a French battery factory in 1977–1982 to explore the relationship between occupational lead exposure and fertility. A total of 354 battery workers, divided into 229 lead-exposed subjects (corresponding with 886 person-years) and 125 non-lead-exposed subjects (corresponding with 598 person-years) were compared, in a person-year analysis, for the risk of infertilitiy. Lead exposure, at any level of absorption, did not appear significantly associated with a reduction in fertility after controlling for potential confounders: age, French origin, educational level, number of children at start of the period, cigarette smoking and exposure to heat. The apparent inconsistency between our results and those of several studies involving biological data and semen analysis is partially explained by recent knowledge relating to predictive value on the pregnancy of semen abnormalities.Corresponding author.  相似文献   
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Interpretation of DNA evidence depends upon the ability of the analyst to accurately compare the DNA profile obtained from an item of evidence and the DNA profile of a standard. This interpretation becomes progressively more difficult as the number of ‘drop-out’ and ‘drop-in’ events increase. Analytical thresholds (AT) are typically selected to ensure the false detection of noise is minimized. However, there exists a tradeoff between the erroneous labeling of noise as alleles and the false non-detection of alleles (i.e. drop-out). In this study, the effect ATs had on both types of error was characterized. Various ATs were tested, where three relied upon the analysis of baseline signals obtained from 31 negative samples. The fourth AT was determined by utilizing the relationship between RFU signal and DNA input. The other ATs were the commonly employed 50, 150 and 200 RFU thresholds. Receiver Operating Characteristic (ROC) plots showed that although high ATs completely negated the false labeling of noise, DNA analyzed with ATs derived using analysis of the baseline signal exhibited the lowest rates of drop-out and the lowest total error rates. In another experiment, the effect small changes in ATs had on drop-out was examined. This study showed that as the AT increased from ~10 to 60 RFU, the number of heterozygous loci exhibiting the loss of one allele increased. Between ATs of 60 and 150 RFU, the frequency of allelic drop-out remained constant at 0.27 (±0.02) and began to decrease when ATs of 150 RFU or greater were utilized. In contrast, the frequency of heterozygous loci exhibiting the loss of both alleles consistently increased with AT. In summary, for samples amplified with less than 0.5 ng of DNA, ATs derived from baseline analysis of negatives were shown to decrease the frequency of drop-out by a factor of 100 without significantly increasing rates of erroneous noise detection.  相似文献   
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Improving vaccine immunogenicity remains a major challenge in the fight against developing country diseases like malaria and AIDS. We describe a novel strategy to identify new DNA vaccine adjuvants. We have screened components of the Toll-like receptor signalling pathways for their ability to activate pro-inflammatory target genes in transient transfection assays and assessed in vivo adjuvant activity by expressing the activators from the DNA backbone of vaccines. We find that a robust increase in the immune response necessitates co-expression of two activators. Accordingly, the combination of tak1 and tram elicits synergistic reporter activation in transient transfection assays. In a mouse model this combination, but not the individual molecules, induced approximately twofold increases in CD8+ T-cell immune responses. These results indicate that optimal immunogenicity may require activation of distinct innate immune signalling pathways. Thus this strategy offers a novel route to the discovery of a new generation of adjuvants.  相似文献   
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The gaseous neurotransmitter nitric oxide plays an important role in the modulation of corticostriatal synaptic transmission. This study examined the impact of frontal cortex stimulation on striatal nitric oxide efflux and neuron activity in urethane-anesthetized rats using amperometric microsensor and single-unit extracellular recordings, respectively. Systemic administration of the neuronal nitric oxide synthase inhibitor 7-nitroindazole decreased spontaneous spike activity without affecting activity evoked by single-pulse stimulation of the ipsilateral cortex. Train (30 Hz) stimulation of the contralateral frontal cortex transiently increased nitric oxide efflux in a robust and reproducible manner. Evoked nitric oxide efflux was attenuated by systemic administration of 7-nitroindazole and the non-selective nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester. Train stimulation of the contralateral cortex, in a manner identical to that used to evoke nitric oxide efflux, had variable effects on spike activity assessed during the train stimulation trial, but induced a short-term depression of cortically evoked activity in the first post-train stimulation trial. Interestingly, 7-nitroindazole potently decreased cortically evoked activity recorded during the train stimulation trial. Moreover, the short-term depression of spike activity induced by train stimulation was enhanced following pretreatment with 7-nitroindazole and attenuated after systemic administration of the dopamine D2 receptor antagonist eticlopride. These results demonstrate that robust activation of frontal cortical afferents in the intact animal activates a powerful nitric oxide-mediated feed-forward excitation which partially offsets concurrent D2 receptor-mediated short-term inhibitory influences on striatal neuron activity. Thus, nitric oxide signaling is likely to play an important role in the integration of corticostriatal sensorimotor information in striatal networks.  相似文献   
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Our aim was to assess the association of a Mediterranean diet and gastroesophageal reflux disease among adult men and women in Albania, a former communist country in South Eastern Europe with a predominantly Muslim population. A cross‐sectional study was conducted in 2012, which included a population‐based sample of 817 individuals (≥18 years) residing in Tirana, the Albanian capital (333 men; overall mean age: 50.2 ± 18.7 years; overall response rate: 82%). Assessment of gastroesophageal reflux disease was based on Montreal definition. Participants were interviewed about their dietary patterns, which in the analysis was dichotomized into: predominantly Mediterranean (frequent consumption of composite/traditional dishes, fresh fruit and vegetables, olive oil, and fish) versus largely nonMediterranean (frequent consumption of red meat, fried food, sweets, and junk/fast food). Logistic regression was used to assess the association of gastroesophageal reflux disease with the dietary patterns. Irrespective of demographic and socioeconomic characteristics and lifestyle factors including eating habits (meal regularity, eating rate, and meal‐to‐sleep interval), employment of a non‐Mediterranean diet was positively related to gastroesophageal reflux disease risk (fully adjusted odds ratio = 2.3, 95% confidence interval = 1.2–4.5). Our findings point to a beneficial effect of a Mediterranean diet in the occurrence of gastroesophageal reflux disease in transitional Albania. Findings from this study should be confirmed and expanded further in prospective studies in Albania and in other Mediterranean countries.  相似文献   
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Given the increasing public interest in how ingredients are processed and the growing demand for organic food products, it is critical to understand consumers’ expectations about the process-related quality of organic products. Consumers perceive organic food to be nutritious, healthy and either natural or less processed, as they are afraid of the loss of nutritional, organoleptic and sensory properties of the food products. However, alternative food processing technologies might generate healthy and safe food options with nutritional quality properties. Simplified communication schemes might help to overcome this barrier for the consumer. The main objective of this study is to propose a working definition of “careful processing” for organic products and test its consistency through an experiment, while being used to rate different processing methods by consumers. Results show that the proposed definition allows the consumer to consistently rate alternative processing technologies. Consumers tend to score alternative processing technologies such as pulsed electric fields and microwaves as less careful, supporting the idea that organic consumers want as little man-made interference in their food products as possible. Results show that a simple but effective definition of careful processing may help consumers to distinguish more organic food products from conventional ones, no matter which communication scheme is used.  相似文献   
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