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Opuntia Milpa Alta is a cactus cultivated, domesticated, hybridized and selected from the plant Opuntia ficus-indica by Mexican agricultural experts, which can be used as fruit and vegetable. Opuntia Milpa Alta leaves and fruit are superior to wild varieties and suitable for storage and transportation. In 1998, Opuntia Milpa Alta was introduced to China from Mexico by the Quality Product Development Center of the Ministry of Agriculture of China. Up to now, the Opuntia Milpa Alta has been cultivated on a certain scale in China. This study aims to identify the research progress and development trends of Opuntia Milpa Alta in China. Papers published between 1998 to 2019 from two major Chinese academic databases (CNKI and Wangfang) with a topic search related to Opuntia Milpa Alta were collected. The research progress and development trends were analyzed based on CiteSpace software of text mining and visualization. The analysis found that Opuntia Milpa Alta has gone through three obvious research phases after being introduced to China. In the first phase, the researchers paid attention to its cultivation method. Subsequently, researchers began to use extraction methods to extract some of its components, such as polysaccharides and flavonoids. Finally, these extracted ingredients began to be used in some biomedical research.  相似文献   

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Analysis of Tobacco and Smoke Condensate for Penicillic Acid   总被引:1,自引:0,他引:1       下载免费PDF全文
Gas chromatographic analyses of smoke condensate from commercial, unfiltered cigarettes spiked with penicillic acid (500 or 1,000 ppm), a reported carcinogenic substance from certain fungi, indicated approximately 3% of unchanged compound was transported in the smoke. Analysis of tobacco on which either Aspergillus ochraceus or Penicillium cyclopium was grown revealed microgram quantities of the compound. Small amounts of the material were also found in moldy tobacco from commercial storage. The results of these investigations suggest that fungi may be a source of carcinogenic compounds in tobacco and tobacco smoke.  相似文献   

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ObjectiveThe purpose of this study was to examine the association between pre and post environmental tobacco smoke (ETS) exposure and behavioral problems in schoolchildren.MethodsIn the cross-sectional 6 cities Study conducted in France, 5221 primary school children were investigated. Pre- and postnatal exposure to secondhand tobacco smoke at home was assessed using a parent questionnaire. Child’s behavioral outcomes (emotional symptoms and conduct problems) were evaluated by the Strengths and Difficulties Questionnaire (SDQ) completed by the parents.ResultsETS exposure during the postnatal period and during both pre- and postnatal periods was associated with behavioral problems in children. Abnormal emotional symptoms (internalizing problems) were related to ETS exposure in children who were exposed during the pre- and postnatal periods with an OR of 1.72 (95% Confidence Interval (CI)= 1.36-2.17), whereas the OR was estimated to be 1.38 (95% CI= 1.12-1.69) in the case of postnatal exposure only. Abnormal conduct problems (externalizing problems) were related to ETS exposure in children who were exposed during the pre- and postnatal periods with an OR of 1.94 (95% CI= 1.51-2.50), whereas the OR was estimated to be 1.47 (95% CI=1.17-1.84) in the case of postnatal exposure only. Effect estimates were adjusted for gender, study center, ethnic origin, child age, low parental education, current physician diagnosed asthma, siblings, preterm birth and single parenthood.ConclusionPostnatal ETS exposure, alone or in association with prenatal exposure, increases the risk of behavioral problems in school-age children.  相似文献   

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The Council on Scientific Affairs of the California Medical Association presents the following inventory of items of progress in occupational medicine. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, and scholars to stay abreast of these items of progress in occupational medicine that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another.The items of progress listed below were selected by the Advisory Panel to the Section on Occupational Medicine of the California Medical Association, and the summaries were prepared under its direction.  相似文献   

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Environmental tobacco smoke (ETS) is estimated to be a significant contributor to in-vehicle human exposure to fine particulate matter of 2.5 μm or smaller (PM2.5). A critical assessment was conducted of a mass balance model for estimating PM2.5 concentration with smoking in a motor vehicle. Recommendations for the range of inputs to the mass-balance model are given based on literature review. Sensitivity analysis was used to determine which inputs should be prioritized for data collection. Air exchange rate (ACH) and the deposition rate have wider relative ranges of variation than other inputs, representing inter-individual variability in operations, and inter-vehicle variability in performance, respectively. Cigarette smoking and emission rates and vehicle interior volume are also key inputs. The in-vehicle ETS mass balance model was incorporated into the Stochastic Human Exposure and Dose Simulation for Particulate Matter (SHEDS-PM) model to quantify the potential magnitude and variability of in-vehicle exposures to ETS. The in-vehicle exposure also takes into account near-road incremental PM2.5 concentration from on-road emissions. Results of probabilistic study indicate that ETS is a key contributor to the in-vehicle average and high-end exposure. Factors that mitigate in-vehicle ambient PM2.5 exposure lead to higher in-vehicle ETS exposure, and vice versa.  相似文献   

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Background—A review by Glantz and Parmley published in 1995 and subsequently widely cited claims to demonstrate that passive smoke exposure increases the risk of heart disease. We have critically examined this claim in the light of the published evidence which they cite and of more recent publications. Methods and results—An updated review of the epidemiological evidence reveals no association between heart disease and ETS exposure in the workplace. Claims of an association with spousal smoking are weakened by the existence of various forms of bias in the studies. They are also undermined by recent reports from three large studies without evident major weaknesses which find essentially no association with spousal smoking. Interpretation of the experimental clinical studies is problematic because it is not possible to expose humans to ETS without their knowledge. For several reasons, short-term effects of exposure to unrealistically high concentrations of ETS throw no useful light on risk of coronary atherogenesis from long-term realistic exposure. In particular, the fact that humans can adapt to reduced ambient oxygen availability needs to be allowed for. Effects of counts of anuclear endothelial cell carcasses in circulating blood after ETS exposure are uninterpretable without basic information on the significance of this endpoint. The need for a realistic animal model for coronary atherosclerosis is not fulfilled by short-term studies in rats, rabbits, hamsters, birds or dogs in which aortic atheromatous plaque formation is used as a surrogate endpoint. Stress from confinement within cages, from the noise of fans and from irritation from high ETS concentrations needs to be controlled for, particularly in experiments on rabbits and birds. This has not been done and there is generally a serious dearth of information on the non-specific or specific effects of other environmental chemicals on many of the endpoints that have been used. Studies on the possible role of platelets in the aetiology of coronary heart disease are difficult to interpret because of confusion between their possible long-term role in atherogenesis and their putative involvement in thrombus formation which results in myocardial infarction. Evidence from an inadequately designed one-day study involving persons exposed to unmeasured amounts of ETS in a hospital corridor provides no insight into mechanisms involved in coronary atherogenesis. A study of the effect of exposure to ETS on the diameter of the brachial artery diameter is open to criticism because of the way in which subjects were recruited and failure to control for potentially important confounders. Conclusion — The available experimental and epidemiological evidence does not justify a conclusion that ETS exposure increases the risk of heart disease.  相似文献   

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Objective

To determine whether exposure to environmental tobacco smoke was associated with oxidative stress among patients hospitalised for acute myocardial infarction.

Design

An existing cohort study of 1,261 patients hospitalised for acute myocardial infarction.

Setting

Nine acute hospitals in Scotland.

Participants

Sixty never smokers who had been exposed to environmental tobacco smoke (admission serum cotinine ≥3.0 ng/mL) were compared with 60 never smokers who had not (admission serum cotinine ≤0.1 ng/mL).

Intervention

None.

Main outcome measures

Three biomarkers of oxidative stress (protein carbonyl, malondialdehyde (MDA) and oxidised low-density lipoprotein (ox-LDL)) were measured on admission blood samples and adjusted for potential confounders.

Results

After adjusting for baseline differences in age, sex and socioeconomic status, exposure to environmental tobacco smoke was associated with serum concentrations of both protein carbonyl (beta coefficient 7.96, 95% CI 0.76, 15.17, p = 0.031) and MDA (beta coefficient 10.57, 95% CI 4.32, 16.81, p = 0.001) but not ox-LDL (beta coefficient 2.14, 95% CI −8.94, 13.21, p = 0.703).

Conclusions

Exposure to environmental tobacco smoke was associated with increased oxidative stress. Further studies are requires to explore the role of oxidative stress in the association between environmental tobacco smoke and myocardial infarction.  相似文献   

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The 3' region of the external transcribed spacer (ETS) of 18S-26S nuclear ribosomal DNA was sequenced in 19 representatives of Calycadenia/Osmadenia and two outgroup species (Compositae) to assess its utility for phylogeny reconstruction compared to rDNA internal transcribed spacer (ITS) data. Universal primers based on plant, fungal, and animal sequences were designed to amplify the intergenic spacer (IGS) and an angiosperm primer was constructed to sequence the 3' end of the ETS in members of tribe Heliantheae. Based on these sequences, an internal ETS primer useful across Heliantheae sensu lato was designed to amplify and sequence directly the 3' ETS region in the study taxa, which were the subjects of an earlier phylogenetic investigation based on ITS sequences. Size variation in the amplified ETS region varied across taxa of Heliantheae sensu lato from approximately 350 to 700 bp, in part attributable to an approximately 200-bp tandem duplication in a common ancestor of Calycadenia/Osmadenia. Phylogenetic analysis of the 200-bp subrepeats and examination of apomorphic changes in the duplicated region demonstrate that the subrepeats in Calycadenia/Osmadenia have evolved divergently. Phylogenetic analyses of the entire amplified ETS region yielded a highly resolved strict consensus tree that is nearly identical in topology to the ITS tree, with strong bootstrap and decay support on most branches. Parsimony analyses of combined ETS and ITS data yielded a strict consensus tree that is better resolved and generally better supported than trees based on either data set analyzed separately. We calculated an approximately 1.3- to 2.4-fold higher rate of sequence evolution by nucleotide substitution in the ETS region studied than in ITS-1 + ITS-2. A similar disparity in the proportion of variable (1.3 ETS:1 ITS) and potentially informative (1.5 ETS:1 ITS) sites was observed for the ingroup. Levels of homoplasy are similar in the ETS and ITS data. We conclude that the ETS holds great promise for augmenting ITS data for phylogenetic studies of young lineages.  相似文献   

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Ratios of GDH activity: NH4+ excretion and ETS activity: oxygenconsumption were measured in western Gulf of Mexico zooplanktonand averaged 18.7 ? 4.3 and 2.65 ? 0.55, respectively. Theseratios were used to estimate NH4+ excretion and respirationrates of two natural zooplankton assemblages sampled quantitativelyfor GDH and ETS activity with a Multiple Opening and ClosingNet and Environmental Sensing System (MOCNESS). Greater than80% of the total GDH and ETS activity 0–200 m was concentratedin depth strata above the chlorophyll maximum, suggesting astrong zooplankton-phytoplankton grazing interaction. GDH activityper unit of zooplankton protein biomass was 3-fold greater inthe upper 100 m than between 100 – 200 m, while ETS activityper unit of zooplankton protein biomass showed no consistentpattern with increasing depth. O:N metabolic quotients wereestimated for the zooplankton sampled with the MOCNESS by ratioingGDH-excretion and ETS-respiratory by atoms. Lowest O:N quotientsoccurred in depth strata above the chlorophyll maximum, suggestinga predominance of protein-based grazing and/or predation. 1Contribution No. 81-013 from the Bigelow Laboratory for OceanSciences  相似文献   

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Measurement of Electron Transport System (ETS) activity in soil   总被引:6,自引:0,他引:6  
Electron transport system (ETS) activity was measured in amended and nonamended soil by measuring the reduction of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT) to iodonitrotetrazolium formazan (INT-formazan), which can be easily extracted with methanol without interference from other compounds found in soil. A high correlation between ETS activity and oxygen consumption was observed. This technique allows rapid quantitative measurements of microbial ETS activity in soil.  相似文献   

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烟草薄片是一种新型的烟草制品,将之回用于卷烟生产过程,既实现了废烟料的综合利用,又提高了卷烟的内在品质。通过采用不同种类的减害材料处理薄片,经过检测分析主流烟气中有害成分含量的变化,筛选出柠檬酸钠、酒石酸钾钠、纳米TiO2-VK-TG01、纳米TiO2-VK-TG02、沸石分子筛这5种合适的材料,作为今后薄片减害的有效添加物。  相似文献   

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Respiratory rates in two areas of the North Adriatic Sea were studied in the context of a PRISMA II Project, with the aim of quantifying the oxidative processes occurring in the frontal system caused by strong riverine discharge. In the northern area, higher respiratory rates and seasonal variations occurred with respect to the southern area. On average, respiratory activity sustained the oxidation of 66.9 nM C h(-1) inside the front and 24.4 nM C h(-1) outside the front. In conclusion, organic matter oxidation inside the front resulted 2.7 times higher than outside the front. Oxidative metabolism in the Northern Adriatic Sea appears mainly governed by river inputs.  相似文献   

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The 3′ region of the external transcribed spacer (ETS) of 18S–26S nuclear ribosomal DNA was sequenced in 19 representatives ofCalycadenia/Osmadeniaand two outgroup species (Compositae) to assess its utility for phylogeny reconstruction compared to rDNA internal transcribed spacer (ITS) data. Universal primers based on plant, fungal, and animal sequences were designed to amplify the intergenic spacer (IGS) and an angiosperm primer was constructed to sequence the 3′ end of the ETS in members of tribe Heliantheae. Based on these sequences, an internal ETS primer useful across Heliantheaesensu latowas designed to amplify and sequence directly the 3′ ETS region in the study taxa, which were the subjects of an earlier phylogenetic investigation based on ITS sequences. Size variation in the amplified ETS region varied across taxa of Heliantheaesensu latofrom approximately 350 to 700 bp, in part attributable to an approximately 200-bp tandem duplication in a common ancestor ofCalycadenia/Osmadenia.Phylogenetic analysis of the 200-bp subrepeats and examination of apomorphic changes in the duplicated region demonstrate that the subrepeats inCalycadenia/Osmadeniahave evolved divergently. Phylogenetic analyses of the entire amplified ETS region yielded a highly resolved strict consensus tree that is nearly identical in topology to the ITS tree, with strong bootstrap and decay support on most branches. Parsimony analyses of combined ETS and ITS data yielded a strict consensus tree that is better resolved and generally better supported than trees based on either data set analyzed separately. We calculated an approximately 1.3- to 2.4-fold higher rate of sequence evolution by nucleotide substitution in the ETS region studied than in ITS-1 + ITS-2. A similar disparity in the proportion of variable (1.3 ETS:1 ITS) and potentially informative (1.5 ETS:1 ITS) sites was observed for the ingroup. Levels of homoplasy are similar in the ETS and ITS data. We conclude that the ETS holds great promise for augmenting ITS data for phylogenetic studies of young lineages.  相似文献   

18.
Acids of lamina and midrib cigarette smoke were converted into trimethylsilyl derivatives and they were analyzed with glass capillary column gas chromatography. Then compositional differences of acids between lamina and midrib cigarette smoke were discussed. The concentrations of organic acids were higher for lamina cigarette smoke than for midrib cigarette smoke. Large concentration difference were found in formic, acetic, propionic, lactic, glycolic, furoic, benzoic, phenylacetic, fumalic and m-hydroxybenzoic acid. Succinic and methylsuccinic acid were similar in lamina smoke and in midrib smoke.

A large amount of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one(amino-carbonyl reaction product) was identified for the first time in lamina smoke.  相似文献   

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A phylogeny of the ITS and ETS for Montanoa (Asteraceae: Heliantheae)   总被引:2,自引:0,他引:2  
A phylogeny of the genus Montanoa based on the internal transcribed spacer (ITS) and the external transcribed spacer (ETS) is presented. Each of the two clades revealed by the Bayesian and parsimony analyses has approximately half of the number of species in the genus. One lineage is composed mostly of central and southern Mexican species whereas the other lineage contains those species endemic to Mesoamerica and South America. The molecular phylogeny is compared to previous phylogenetic hypotheses based on morphological characters. Key features in the structure of the capitulum such as pale morphology, heavily used in the past to construct hypotheses of relationship within the genus, are viewed as of minimal value to circumscribe natural groups. The relationships of Montanoa to other genera in the Heliantheae are briefly discussed.  相似文献   

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