首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Respiratory syncycial virus (RSV) is the first cause of acute lower respiratory tract infection in Chilean infants. A significant impact of nutrition on clinical course of these infections has been described. In order to analyze the association between nutritional status (NS) and clinical course of infants hospitalized with acute lower respiratory tract infection due to RSV, 130 infants (mean age 5.8 +/- 4.9 m) without chronic diseases, admitted to hospital with confirmed RSV infection, were studied. Clinical course of disease was assessed (hospitalization days and days with oxygen therapy) according to nutritional status on admission (weight/length (W/L), ratio, arm muscle area, lymphocyte count and albumin), antropometrics changes, and hospital dietary intake. On admission prevalence of malnutrition by W/L (z score) was 1%, 14% overweight and 8% were obese. Median value of hospitalization days was 5 d (2-29 d) and days receiving oxygen was 3 d (0-19 d). Longer admission were observed in fasted patients than in those who were fed everyday (Wilcoxon and Log-rank test, 8 d vs 5 d; P < 0.01). Obese children (Wilcoxon and Log-rank test, 5 d vs. 3d in normal patients; P < 0.05), and patients not fed enterally (Wilcoxon and Log-rank test, 7 d vs. 3 d; P < 0.01) required oxygen for longer time. Fasting and severity of illness (Tal score) were correlated variables (X2 0.001). The multivariate analysis showed an association of Tal score and NS on admission, with days receiving oxygen therapy. We conclude that obesity is a risk factor for worse clinical course of acute lower respiratory tract infection in Chilean infants with RSV infection and without chronic disease.  相似文献   

2.
Responses by adultOryzaephilus surinamensis (L.) andOryzaephilus mercator (Fauvel) to various food volatiles were assessed by means of a two-choice, pitfall olfactometer. The individual experimental stimuli, all potential products of lipid oxidation, had a range of attractive doses of 1000-fold over the test dose ranges of 0.001–100 gmg, or 0.01–1000 gmg. Of 13 aliphatic C3-C14 aldehydes and benzaldehyde tested forOryzaephilus spp., 10 C3-C10 aliphatic aldehydes and benzaldehyde showed some attractiveness for both species. ForO. mercator, nonanal had the lowest lower threshold for positive response at 0.01 g. The addition of small amounts of nonanal or of a 111 mixture of hexanal, octanal, and nonanal to small amounts of cucujolide aggregation pheromones enhanced response by mixed-sexO. mercator to the pheromones. Eleven aliphatic C2-C9 free fatty acids showed some attractiveness for bothOryzaephilus spp. Isovaleric acid and valeric acid had the lowest lower thresholds for positive response at 0.1 g forO. mercator andO. surinamensis, respectively. Four olefinic oat volatiles were found to possess various degrees of attractiveness for bothOryzaephilus spp. The data suggest that food volatiles in this study might be used byOryzaephilus spp. as host-finding kairomones in nature.Research supported by the Natural Sciences and Engineering Research Council of Canada, Strategic Grant G0958 and Operating Grants A3881 and A3785.  相似文献   

3.
Laboratory experiments were conducted to study the behavioral activity of grain-derived volatiles as attractants and pheromone synergists forSitophilus oryzae, an internal-feeding pest of sound grain, andTribolium castaneum, an external-feeding pest of damaged grains and flour. Behavioral studies with two-choice pitfall bioassays determined that the fresh grain volatiles valeraldehyde, maltol, and vanillin were attractive toS. oryzae at various doses, butT. castaneum were not attracted to any dose of any of these three compounds. When oils from pressed grains were bioassayed, sesame oil was significantly repellent and oat and wheat germ oils were attractive toS. oryzae. However, rice, soybean, oat, wheat germ, and corn oils were all attractive toT. castaneum. A commercial food product composed primarily of soybean oil and wheat germ was highly attractive toT. castaneum, but elicited no response fromS. oryzae. A combination of the three grain volatiles valeraldehyde, maltol, and vanillin with the synthetic pheromone sitophinone was more attractive toS. oryzae than either the pheromone alone or the tripartite grain volatile mix. Similarly, a combination of the commercial food product with the pheromone 4,8-dimethyldecanal was more attractive toT. castaneum than either food alone or pheromone alone. Behavioral responses to grain volatiles may reflect the ecological niche of the granivore:S. oryzae colonizes sound grain and is attracted to volatiles characteristic of fresh grain, whileT. castaneum utilizes damaged or deteriorated grains and responds best to oils characteristic of damaged or fungus-infested grain. Synergism of food odors and pheromones suggests that more effective traps can be devised for management of these pest insects.  相似文献   

4.
结合本公司目前场地喷涂施工的现状介绍并分析了施工中常见的一种漆膜缺陷———针孔及其修正方法,并分别从技术和管理上提出了相应的改进建议。  相似文献   

5.
6.
The chemical mediation of host-finding was investigated for the dusky sap beetle,Carpophilus lugubris Murray. GC-MS analysis of the headspace volatiles above whole-wheat bread dough inoculated with baker's yeast, a substrate previously determined to be an effective attractant, revealed seven major components in the following order of decreasing concentration: ethanol, acetaldehyde, 2-methylpropanol, 3-methylbutanol, propanol, 2-methylbutanol, and ethyl acetate. Solutions of these seven compounds blended so as to mimic the odor of whole-wheat bread dough elicited upwind orientation from 1.8 m in a wind tunnel byC. lugubris at a level comparable to that elicited by the bread dough. A series of bioassays investigating the role of individual components from the synthetic blend determined that all seven compounds contributed to behavioral activity; however, the simplest blend evoking attraction comparable to bread dough included acetaldehyde, ethyl acetate, 2-methylpropanol, and 3-methylbutanol. Of these compounds, acetaldehyde was essential, ethyl acetate was interchangeable with ethanol or partially replaceable with propanol, and 2-methylpropanol and 3-methylbutanol were partially replaceable with a combination of the other alcohols. Headspace volatiles above aseptic or fungus-inoculated tomato, banana, sweet corn, and strawberry were also qualitatively and quantitatively analyzed. This study suggests thatC. lugubris locates its food sources by response to variable blends of common volatile constituents of plants and fungi.  相似文献   

7.
Platypus milk fat contains 98.5% triglyceride. Polyunsaturates (C18∶2–C22∶5) account for 29% of the triglyceride fatty acids in the milk fat and 32% of the total fatty acids in the lipid of the food of the platypus. Linoleate and arachidonate are the major ω6 polyunsaturates of both food and milk lipids. However, while the ω3 polyunsaturates linolenate and eicosapentaenoate are present in both food and milk, docosapentaenoate is present in meaningful amounts in milk only. It is suggested that with the exception of 22∶5ω3, the polyunsaturates in platypus milk originate in the diet.  相似文献   

8.
The effect of protein and birch bark powder (BBP) content of forage on food consumption and growth of root voles (Microtus oeconomus) was studied by feeding young voles with eight different diets for two weeks. Voles ate more when the protein content of forage was moderate (6%) or low (3%), and when BBP was added to the diets, as compared to a high (12%) protein diet without BBP addition. On high and moderate protein diets voles gained weight, whereas on low protein diets they lost weight. Addition of BBP caused reduced growth or weight loss. Consuming a diet with moderate (6%) protein and high BBP (20%) resulted in high mortality (9 of 10 died). These results show that root voles need at least 6% protein for growth and that the effect of birch bark depends on the protein content of the forage.  相似文献   

9.
Zhao  Chuanlin  Xu  Ye 《Topics in Catalysis》2020,63(11-14):1375-1376
Topics in Catalysis - The original version of this article unfortunately contained an error in Fig.&nbsp;6. The authors would like to correct the error with this erratum. The errors were due to...  相似文献   

10.
The first dinuclear bis(mercaptoimidazolyl)methane metal complex, the lead(II) derivative [Pb2(BmmMe)5](ClO4)4, has been prepared and fully characterized using a combination of analytical and spectroscopic techniques. X-ray crystallography confirmed the presence in the solid state of two dicationic [Pb(BmmMe)2]2+ fragments bridged by the fifth BmmMe ligand, which uses an unprecedented unidentate:bidentate (μ-κ1-S2-S,S) coordination mode to link the two metal centers.  相似文献   

11.
Nutrient Cycling in Agroecosystems - A correction to this paper has been published: https://doi.org/10.1007/s10705-021-10152-7  相似文献   

12.
简述了二恶英的公害性及有关特性;二恶英毒性表示法及二恶英的传播途径。重点介绍了二恶英的形成条件和二恶英的控制技术进展。  相似文献   

13.
Fatty acid content of sicklepod (Cassia tora L.) leaves and stems was determined by GLC. Major constituents were identified as palmitate, stearate, oleate, linoleate and linolenate at 20.8%, 6.4%, 5.7%, 13.1% and 26.0%, respectively, of the total fatty acids present. The remainder of the fatty acids occurred in shorter or longer homologues and branched chain compounds. Chain lengths up to C34 were found. Published as Journal Series No. 289 of the University of Georgia, College of Agricultural Experiment Stations, Ga. 30212.  相似文献   

14.
Two hydrolyzable polymers, poly(methylene oxide) (PMO) and poly(glycolic acid) (PGA), were tested for association with mechanical systems to promote diversion of formation acid treatments in oil wells. Samples were confined to chemical products commonly employed in oil well completion processes, HCl 15% w/w and NaCl 23% w/w aqueous solutions, in separate metallic cylindrical cells, under conditions observed in southeastern Brazilian offshore fields (50 and 75°C and pressure of 41.4 MPa). Pristine samples were characterized by 13C-NMR. Hydrolytic influences were evaluated by differential scanning calorimetry, scanning electron microscopy, wide angle X-ray diffraction, and computerized microtomography. The intense effects observed showed a specific correspondence with each tested polymer and were evidenced by postexposure analysis. The results indicate that both polymers can be used in association with mechanical diverting systems to promote chemical treatment distribution and, therefore, improve oil well productivity. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47362.  相似文献   

15.
The outdoor weathering of polyethylene homopolymer under exposure in air and in sea water was studied. Rate of deterioration as indicated by the loss in mean ultimate extension was found to be slower when the material was weathered in sea water compared to that in air. The difference in rates is explained in terms of the lack of heat buildup in plastic material floating in sea water. A similar study on a commercially available ethylene–carbon monooxide copolymer indicated rapid photodegradation under both exposure conditions.  相似文献   

16.
The presence of intraspecific variation in toxicity and its relationship with biological or ecological factors were studied in the spongeCrambe crambe. Within-specimen (periphery and central part), between-size (<1000 mm2 in area, between 1000 and 10,000 mm2 and >10,000 mm2) and between-habitat (well-illuminated and dark communities) variations in toxicity were evaluated by the Microtox bioassay. Quantitative differences were detected that were not attributable to within-specimen variation but to size and habitat effects. Habitat comparisons showed that sponges in the shaded habitat were significantly more toxic than those of the well-illuminated community. Sponges of the smaller size classes displayed significantly less toxicity than the medium-sized specimens. Results are interpreted under the optimal defense theory and their ecological implications are considered.  相似文献   

17.
In the iguanid lizardDipsosaurus dorsalis, chemical food stimuli were discriminated from other odorants by vomerolfaction. This was demonstrated in a 2 × 3 experiment in which groups of lizards with sealed vomeronasal ducts or sham-sealed vomeronasal ducts responded to carrot chemical stimuli, cologne, and distilled water presented on cotton-tipped applicators. Abilities to detect and discriminate food chemicals were abolished in lizards having sealed vomeronasal ducts. For tongue-flick attack score and number of lizards biting, the sham-sealed group responded more strongly to carrot stimuli than to the control stimuli, but the group having sealed ducts did not. Lizards having sham-sealed ducts responded more strongly to carrot stimuli than did lizards having sealed ducts; responses by the two groups of lizards to control stimuli did not differ. Tongue-flicking occurred when the vomeronasal system detected a chemical stimulus from either carrot or cologne. Biting occurred only when the vomeronasal organ detected food stimuli (from carrot). Most duct-sealed lizards opened their mouths, some repeatedly. Mouth-opening thus occurs when the vomeronasal organ does not detect chemicals. It may be an attempt to stimulate or prime the vomeronasal organ or to dislodge the sealant.  相似文献   

18.
Iranian Polymer Journal - The article listed above was initially published with typo error in first author name.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号