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Tobacco--particularly smoked products--has been associated with great harm and growing public disapproval and can be expected to suffer in the marketplace. This situation has created opportunities for other less harmful nicotine-containing products such as smokeless tobacco and nicotine replacement products, which are gaining public support. Little is known about the level of nicotine intake in our society. Tobacco sales are known, but how much nicotine is extracted and actually absorbed by users is largely unknown. The present study is a first attempt to estimate uptake of nicotine from tobacco and nicotine replacement products and to map nicotine consumption in a few countries, with special emphasis on Sweden. Relevant pharmacokinetic studies for three types of nicotine-containing products (cigarettes, smokeless tobacco, and nicotine replacement products) were analyzed for bioavailable nicotine. Estimates of nicotine intake from each category were made. These were then multiplied by the amount consumed in the respective countries. Tobacco consumption statistics were usually from official records of taxed sales. In Sweden about 54% of all nicotine intake comes from smoked sources, 45% from nonsmoked tobacco, and 1.3% from nicotine replacement products. For men, 63% of the nicotine consumed comes from nonsmoked tobacco. Per-capita nicotine intake per year for adults aged 15 years or older is 3,321 mg for Austria, 3,043 mg for Sweden, 3,014 mg for Denmark, 2,955 mg for the United States, 2,244 mg for Norway, and 2,023 mg for Finland. Compared with cigarette smokers, snus users seem to have a somewhat higher daily intake (34 mg vs. 25 mg). The cleanest nicotine products, nicotine replacement products, represent a negligible part (about 1%) of the total nicotine consumption in most countries.  相似文献   

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桉树速生丰产林--我国林浆纸一体化的必然选择   总被引:7,自引:0,他引:7  
徐大平 《中华纸业》2006,27(4):14-25
以翔实的资料和数据,研究论证了桉树人工林的发展优势及生态影响,做出了基本结论。  相似文献   

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The mae1 gene of the yeast Schizosaccharomyces pombe was identified on the basis of its ability to complement a mutant defective in the transport of malic acid. Analysis of the DNA sequence revealed an open reading frame of 1314 base pairs, encoding a polypeptide of 438 amino acids with a predicted molecular weight of 49 kDa. A hydropathy profile of the predicted amino acid sequence revealed a protein with ten membrane-spanning or associated domains and hydrophilic N- and C- termini. The predicted secondary structure of the protein is similar to models proposed for other integral mambrane proteins from both prokaryotes and eukaryotes. The S. pombe mae1 gene encodes a single mRNA of 1·5 kb. The mae1 gene is expressed constitutively and is not subject to catabolite repression as was previously reported for the malate permease systems of Candida utilis and Hansenula anomala. The mae1 gene was mapped 2842 bp 5′ to the MFm1 gene on chromosome I. Transport assays revealed that the mae1 gene encodes a permease involved in the uptake of L-malate, succinate and malonic acid. The sequence of the S. pombe mae1 gene is available in GenBank under Accession Number U21002.  相似文献   

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Polyketides are a structurally diverse class of secondary metabolites produced by bacteria, fungi, plants and animals. The fungal genus Fusarium includes agronomically important plant pathogenic and mycotoxin-producing species and produces numerous polyketides. The study further characterized a polyketide synthase-encoding gene (PKS3 = PGL1) that was previously identified in F. graminearum and F. verticillioides. Disruption of the F. verticillioides PGL1 indicated that it is required for the production of the dark pigment in perithecial walls, as previously shown in F. graminearum. A third PGL1 orthologue was identified in the genomic sequence of N. haematococca (anamorph F. solani f. sp. pisi). Analysis of the carboxy-terminal end of the deduced PGL1 protein indicated that it had a functional domain related to dehydrogenases/reductases that is sometimes present in non-ribosomal peptide synthetases. Comparison of the genomic regions flanking PGL1 in F. graminearum, F. verticillioides and N. haematococca revealed that the extent of gene synteny in this region was greater between F. graminearum and F. verticillioides than between either of these species and N. haematococca. Southern blot analysis indicated that PGL1 occurs widely within the genus Fusarium including species with no known sexual stage.  相似文献   

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A cold enrichment and the modified FDA selective enrichment method were compared for their ability to detect Listeria monocytogenes and other Listeria species from various ready-to-eat foods on sale in the UK. Of 57 food samples examined using cold enrichment, five yielded L. monocytogenes, and two L. innocua. The FDA enrichment method yielded three samples positive for L. monocytogenes only. Foods examined included soft cheeses, fermented meat sausages, pates and salads.  相似文献   

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Wheat is primarily used for bread-making. However, fungal diseases, grain moisture at harvest and low-protein contents strongly influence the quality of the wheat flour, thus creating challenges for traders, millers and commercial bakers who struggle to produce consistently high-quality products. This paper address the replacement of low-protein/wholemeal flour functionality for bread-making purposes. Three hydrocolloids, xanthan gum, dextran and hydroxypropyl methylcellulose, were incorporated into bread recipes based on high-protein flours, low-protein flours and coarse wholemeal flour. Hydrocolloid levels of 0–5 % (flour basis) were used in bread recipes to test the water absorption. The quality parameters of dough (farinograph, extensograph, rheofermentometre) and bread (specific volume, crumb structure and staling profile) were determined. Results showed that xanthan had negative impact on the dough and bread quality characteristics. HPMC and dextran generally improved dough and bread quality and showed dosage dependence. Volume of low-protein flour breads were significantly improved by incorporation of 0.5 % of the latter two hydrocolloids. However, dextran outperformed HPMC regarding initial bread hardness and staling shelf life regardless the flour applied in the formulation.  相似文献   

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Considerable evidence indicates that smoking behavior is under a degree of genetic influence. We conducted a systematic review of candidate gene studies of smoking behavior and, where sufficient studies existed, combined reported data using meta-analytic techniques. A total of 41 studies were identified by the search strategy, of which 28 contributed to the meta-analysis. The meta-analysis included data on the DRD2, DAT, 5HTT, and CYP2A6 genes and smoking behavior. Categorical data were extracted on smoking status (never-smoker, ex-smoker, current smoker). Continuous data were extracted on number of cigarettes smoked per day. Evidence indicated effects of the DRD2 Taq1A polymorphism and smoking initiation, the 5HTT LPR and CYP2A6 reduced-activity polymorphisms and smoking cessation, and the DRD2 Taq1A and CYP2A6 reduced-activity polymorphisms and cigarette consumption. The evidence for an effect of specific genes was modest, however, and evidence indicated substantial between-study heterogeneity in most cases, with the exception of the effects of the 5HTT and CYP2A6 genes on smoking cessation. When a random-effects model was applied to analyses in which evidence indicated significant heterogeneity, the effects were in all cases no longer statistically significant. The evidence for a contribution of specific genes to smoking behavior remains modest. Implications for the design of future studies are discussed, such as the need for the development of more specific phenotypes to increase the genetic signal in candidate gene studies.  相似文献   

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The alga Polytoma uvella was found to be a good source of both soluble and starch-bound NDPG-glucosyltransferase. The properties of the enzymes were similar to those of transferases from other plant sources, but differed in some respects. ADPG and UDPG acted as glucose donors, while maltose was inactive as glucose acceptor. Acetone preparations of the soluble enzyme were stable, but β-amylase could not be completely removed without inactivating the transferase. They also contained oligosaccharides of the maltose series.  相似文献   

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Vitamin insufficiency disrupting metabolism, enhances the course of any disease and hinders successful treatment. In this connection the treatment of any patient should include a correction of the existing polyvitaminic deficiency and maintain of optimal provision by all micronutrients. Using vitamins in the treatment of primary avitaminosis, correction of secondary metabolism and function of vitamins, as well as medicamental therapy and various restrictrions in a diet is undisputed. Congenital genetically defects in the metabolism and function of vitamins form a special group of diseases that require high doses of vitamins and its parenteral injection.  相似文献   

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One solution for reducing tobacco use is to expand health insurance coverage for tobacco dependence treatments (TDTs), but the public demand for a coverage mandate is unknown. This study finds that demand for coverage of TDTs among a random sample of adult Californians with employer-sponsored health insurance is strong, with 62% indicating that health insurers should be required to offer coverage as part of their standard plans and a majority (56%) indicating a willingness to pay $3 more for their annual health insurance premium to finance cessation coverage. Compared to never smokers, current and former smokers are no more likely to support a benefit mandate to require coverage of cessation treatments, but the adjusted odds are approximately three times greater that current and former smokers are willing to pay $3 more toward their annual premium to finance cessation coverage. Liberals had higher adjusted odds of supporting a benefit mandate and of being willing to pay a higher premium compared to conservatives. Non-whites had higher adjusted odds of supporting a mandate compared to whites, with no differences by race/ethnicity in willingness to pay a higher premium. There were no differences in preferences for a benefit mandate or willingness to pay a higher premium as a function of age, gender or income. These findings have important policy implications for a state health insurance mandate to cover tobacco dependence treatments.  相似文献   

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An automated procedure, using p-hydroxybenzoic acid hydrazide as the colour reagent, for the determination of carbohydrate in solution is described. The method is applicable to the determination of available carbohydrate in foodstuffs. The results of analysis of some foods are given, and compared with values obtained by a manual procedure.  相似文献   

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Metal flux at consuming interfaces (e.g., sensors or microorganisms) is simulated in environmental multiligand systems using a new numerical code, MHEDYN (Multispecies HEterogeneous DYNamics), based on the lattice Boltzmann method. The attention is focused on the computation of the maximum flux (i.e.,the flux controlled by diffusion-reaction in solution) of Cu(II). Part III described flux computation in the presence of simple ligands and fulvic/humic substances. This paper (Part IV) discusses the case of metal complexes formed with aggregates including a broad range of sizes and diffusion coefficients and their mixture with simple and fulvic ligands under typical natural water conditions. This paper describes the dynamic contribution of the various size classes of aggregate Cu(II) complexes for the first time. In two typical waters containing mixtures of ligands, the contribution of aggregates is found to be small, whereas that of fulvics may play a major role, even under pH conditions where the lability of their Cu(II) complexes is low. These results point out the great usefulness of MHEDYN for dynamic speciation in very complex mixtures. In all cases, MHEDYN enables us to compute the concentration profile of each complex and itstime evolution, as well as the steady-state flux and the corresponding contribution of each complex to the flux. Thus, MHEDYN should be very useful for comparing theoretical predictions with experimental measurements of metal bioavailability or of dynamic sensor response in a complete aquatic medium.  相似文献   

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This study evaluated the relationship between smoking cessation treatment outcome and the DRD2 polymorphism. Participants were 134 smokers who took part in a larger clinical trial evaluating the effects of an antidepressant medication (venlafaxine or placebo) plus standard care (brief counseling and nicotine replacement therapy). Venlafaxine is an antidepressant that inhibits the reuptake of serotonin and norepinephrine. A1 smokers were expected to quit significantly less often on placebo, although the abstinence rates between A1s and A2s on active drug were not expected to differ (i.e., an interaction between genotype and drug was hypothesized). In addition, antidepressant therapy was expected to have a similar genotype x treatment interaction on negative affect reduction. The results showed that smokers carrying the DRD2 A1 allele (A1/A1/A2) quit significantly less often than the homozygous A2s (OR=1.54, 95% CI=1.01-2.36). No interaction with treatment was observed. A significant pharmacogenetic effect of the drug on negative mood while quitting also was noted. Smokers absent the A1 allele (A2/A2) responded to the drug with a substantial reduction in negative affect, whereas those with the A1 allele showed no significant reduction in negative mood, F(1, 130)=5.95, p=.01. These results are contrary to expectations and suggest that although A1s may have more difficulty quitting, adding venlafaxine does not improve abstinence or mood. However, the results for the A2s provide evidence for a genotype-specific response to a pharmacological intervention, which could have implications for the development of future treatments.  相似文献   

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Contamination of cereals with mycotoxins such as beauvericin (BEA), enniatins (Ens) and moniliformin (MON) is mainly caused by Fusarium avenaceum and F. tricinctum. This is a world-wide problem which requires rapid and sensitive detection methods. To allow for high throughput screening of large numbers of samples, a diagnostic PCR method was developed for the simultaneous detection of F. avenaceum and F. tricinctum. The interspecific divergence found in the Fusarium-specific CYP51C gene was used to design species-specific PCR primers. The specificity of the assay was demonstrated for DNA samples extracted from a wide range of Fusarium species belonging to the Fusarium head blight (FHB) complex, as well as for naturally-infected grain samples. The PCR-amplified products were digested with the restriction enzyme XbaI to enable differentiation between F. avenaceum and F. tricinctum. This PCR- restriction fragment length polymorphism (RFLP) assay proved to be a simple and relatively inexpensive method highly suited for routine detection and identification of F. avenaceum and F. tricinctum in wheat samples.  相似文献   

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The objective of this study was to develop a fluorescent bacteriophage assay (FBA) for the detection of E. coli O157:H7 in ground beef and raw milk. The FBA is a two step assay that combines immunomagnetic separation, to separate the target organism from mixed culture, with a highly specific fluorescently stained bacteriophage to label the E. coli O157:H7 cells. When used in conjunction with flow cytometry, the FBA was able to detect 2.2 CFU/g of artificially contaminated ground beef following a 6 h enrichment. Between 10(1) and 10(2) CFU/ml of artificially contaminated raw milk were detectable after a 10 h enrichment step. The results show that the FBA is potentially useful as a rapid technique for the preliminary detection of E. coli O157:H7 in food.  相似文献   

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The task of the test program was the replacement of more subjective and time-consuming sensory methods by instrumental or chemical ones. In the case of meat flavour concentrates (MFC) and their burnt-bitter flavour the cluster analysis resulted in the following: –The test program was based on 20 samples produced by statistical plans (central composite design for 3 explanatory variables). Starting with 10 sensory and 40 instrumental methods the latter have been reduced to 10 methods considering the suppositions for application of the cluster analysis. –The 20 samples were tested on one side by a trained sensory panel for the intensity of the “burnt-bitter” flavour and parallely by the selected 10 instrumental values. This resulted in both cases in the differentiation into 3 clusters with significant differences. –For evaluation of MFC as to their “burnt-bitter” flavour it was shown that the sensory evaluation can be replaced or supported by analytical data successfully. Thus cluster analysis is a useful tool for this purpose delivering transparent results.  相似文献   

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