oalib

OALib Journal期刊

ISSN: 2333-9721

费用：99美元

投稿

时间不限

( 2673 )

( 2672 )

( 2208 )

( 2027 )

自定义范围…

匹配条件： “Cynthia C Silva” ，找到相关结果约309628条。
列表显示的所有文章，均可免费获取
第1页/共309628条
每页显示 条
Risk Factors for Surgical Site Infection after Hip Arthroplasty: A Multicentric Study  [PDF]
Gabriel B. Tofani, Gustavo P. Irffi, Lucas F. Silva, Cynthia C. M. da Silva, Bráulio R. G. M. Couto, Gilberto D. Miranda, Carlos E. F. Starling
Surgical Science (SS) , 2016, DOI: 10.4236/ss.2016.72008
Abstract: The objective of this study is to answer three main questions: What is the risk of wound infection for patients undergoing hip arthroplasty? What are the main etiologicagents of surgical site infection (SSI)? What are the risk factors most associated with surgical site infection? Method: This was a multicentric, retrospective cohort study which analyzed data collected in five general hospitals in Belo Horizonte, Brazil, between the period of January 2009 and December 2013. The continuous parameters studied were age, length of hospital stay before surgery, duration of surgery, number of professionals at surgery and number of hospital admissions. Categorical variables were surgical wound classification (clean, clean contaminated, contaminated, dirty/infected), American Society of Anesthesiologists (ASA) score (I, II, III, IV, V), type of surgery (elective, emergency), general anesthesia (yes, no), prophylactic antibiotic (yes, no), trauma surgery (yes, no) and Nosocomial Infections Surveillance (NNIS) risk index (IRIC = 0, 1, 2, 3). Results: Estimated SSI risk was 3.2% (95% C.I. = 2.6% to 4.1%) and risk of osteomyelitis was 0.6% (95% C.I. = 0.4% to 1.1%). ASA score > 2, general anesthesia, length of hospital stay before surgery higher than four days, more than two professionals at surgical field and duration of surgery higher than five hours were risk factors for SSI after hip prosthesis (p < 0.05). The final multiple logistic regression analysis indicated that the modified NNIS risk was independently associated with surgical site infection after arthroplasty of hip. Conclusion: Despite the modified NNIS index being a risk factor for SSI, none of its independent variables was statistically significantly in the logistic model (p > 0.100). Each modified NNIS risk category increased the chance of a patient being infected by almost three times, when compared with the previous category (OR = 2.82; p = 0.011).
Characterization and Lifetime Estimation of High Density Polyethylene Containing a Prodegradant Agent  [PDF]
Cynthia D. C. Erbetta, Raquel C. S. Azevedo, Karen S. Andrade, Maria Elisa S. R. e Silva, Roberto F. S. Freitas, Ricardo G. Sousa
Materials Sciences and Applications (MSA) , 2017, DOI: 10.4236/msa.2017.813072
Abstract: High density polyethylene (HDPE) samples, containing different concentrations of prodegradant additive d2w？, were prepared. The properties of the samples were evaluated through differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), rheometry, and scanning electron microscopy (SEM). The work contributes to decreasing the products made of non-biodegradable polymeric materials derived from fossil sources which are have become a problem due to their increasingly inappropriate disposal and long degradation time in the environment. The obtained results indicated that there was no degradation of the samples due to processing. No significant changes in melting temperature, crystallinity, viscoelastic behavior, molecular weight and chemical composition were observed. Images from SEM analysis showed particles on HDPE surface, attributed to prodegradant additive d2w？. Oxidation Onset Temperature (OOT) results showed that the additive d2w？ accelerated the degradation of HDPE. The activation energy (Ea) was determined by Ozawa-Wall-Flynn method. The obtained values were used for lifetime estimation of the samples. At 25°C, HDPE with d2w？ showed a lifetime 50% higher than that of HDPE without this additive. This fact is attributed to the presence of stabilizers in masterbatch d2w？ and the absence of oxygen in thermogravimetric analysis.
Saprophytic fungus collection by africanized bees in Brazil
Modro, Anna F H;Silva, Izabel C;Message, Dejair;Luz, Cynthia F P;
Neotropical Entomology , 2009, DOI: 10.1590/S1519-566X2009000300022
Abstract: cladosporium sp. collection by bees (apis mellifera l.) was observed in brazil at an apiary located in minas gerais, during november10-23, 2005, characterized by high air relative humidity and low availability of food resources (pollen and nectar).the nutritional composition of the fungi pellets presented high protein value, ethereal extract and organic matter.
Analysis of pollen load based on color, physicochemical composition and botanical source
Modro, Anna F.H.;Silva, Izabel C.;Luz, Cynthia F.P.;Message, Dejair;
Anais da Academia Brasileira de Ciências , 2009, DOI: 10.1590/S0001-37652009000200014
Abstract: pollen load samples from 10 hives of apis mellifera (l.) were analyzed based on their physicochemical composition and botanical source, considering color as a parameter for quality control. in seven samples it was possible to establish the occurrence of more than 80% of a single pollen type, characterizing them as unifloral but with protein content variation. one of the samples was exclusively composed of saprophytic fungi (cladosporium sp.). comparing the mean results of the fungi loads with those of the nutritional components of pollen load, the former presented higher protein, mineral matter and dry matter and lower organic matter, ethereal extract and total carbohydrate values. the monochromatic samples met the physicochemical specifications regulating pollen load quality. the results showed that homogeneous coloration of the pollen load was not found to be a good indication of unifloral pollen, confirming the importance of physicochemical analysis and melissopalynological analysis for characterization of the quality of commercial pollen load.
Comparison of microsatellites and isozymes in genetic diversity studies of Oryza glumaepatula (Poaceae) populations
Marines M. G Karasawa,Roland Vencovsky,Cynthia M Silva,Daruska C Cardim
Revista de Biología Tropical , 2012,
Abstract: The study of the genetic structure of wild plant populations is essential for their management and conservation. Several DNA markers have been used in such studies, as well as isozyme markers. In order to provide a better comprehension of the results obtained and a comparison between markers which will help choose tools for future studies in natural populations of Oryza glumaepatula, a predominantly autogamous species, this study used both isozymes and microsatellites to assess the genetic diversity and genetic structure of 13 populations, pointing to similarities and divergences of each marker, and evaluating the relative importance of the results for studies of population genetics and conservation. A bulk sample for each population was obtained, by sampling two to three seeds of each plant, up to a set of 50 seeds. Amplified products of eight SSR loci were electrophoresed on non-denaturing polyacrylamide gels, and the fragments were visualized using silver staining procedure. Isozyme analyses were conducted in polyacrylamide gels, under a discontinuous system, using six enzymatic loci. SSR loci showed higher mean levels of genetic diversity (A=2.83, p=0.71, A P=3.17, Ho=0.081, He=0.351) than isozyme loci (A=1.20, p=0.20, A P=1.38, Ho=0.006, He=0.056). Interpopulation genetic differentiation detected by SSR loci (R ST=0.631, equivalent to F ST=0.533) was lower than that obtained with isozymes (F ST=0.772). However, both markers showed high deviation from Hardy-Weinberg expectations (F IS=0.744 and 0.899, respectively for SSR and isozymes). The mean apparent outcrossing rate for SSR ( =0.14) was higher than that obtained using isozymes ( =0.043), although both markers detected lower levels of outcrossing in Amazonia compared to the Pantanal. The migrant number estimation was also higher for SSR (Nm=0.219) than isozymes (Nm=0.074), although a small number for both markers was expected due to the mode of reproduction of this species, defined as mixed with predominance of self fertilization. No correlation was obtained between genetic and geographic distances with SSR, but a positive correlation was found between genetic and geographic distances with isozymes. We conclude that these markers are divergent in detecting genetic diversity parameters in O. glumaepatula and that microsatellites are powerful for detecting information at the intra-population level, while isozymes are more powerful for inter-population diversity, since clustering of populations agreed with the expectations based on the geographic distribution of the populations using this marker El
Microperfura es em Foraminíferos Bent nicos da Lagoa Pitanguinha, RJ.
Mariana Cardoso,Daniele da Silva Batista,Cynthia Damazio,Maria Célia Elias Senra
Anuário do Instituto de Geociências , 2007,
Abstract: Os foraminíferos bent nicos têm sido foco deestudos paleoecológicos por serem geralmente abundantese possuírem bom potencial de preserva odevido à carapa a de composi o calcárea ou aglutinada.S o indicadores potenciais do ambiente, e seuestado de preserva o é um reflexo direto de fatoresambientais, entre eles, a atividade bioerosiva. Os organismosperfuradores s o os principais agentes debioeros o em ambiente carbonático, comprometendoa preserva o dos esqueletos. A lagoa Pitanguinhafaz parte do complexo lagunar em Araruama, noEstado do Rio de Janeiro, juntamente com outraslagunas distribuídas ao longo de uma estreita planície.Localizada na restinga de Massambaba, entreas latitudes 22°55’42’’ e 22°56’00’’S e longitudes42°20’45’’ e 42°2°21’30’’W, tem sua forma o relacionadaa duas transgress es marinhas sucessivas.O presente estudo tem por objetivo registrar tra osde bioeros o em foraminíferos bent nicos da LagoaPitanguinha, Rio de Janeiro. Das amostras cedidaspara estudo pelo LABIOTAL/Ecb/UNIRIO, foramretirados 50 cm3 de sedimento, lavados em água correnteempregando-se peneiras 53, 75 e 212 mesh,desidratados em temperatura ambiente e triadas paraa identifica o dos foraminíferos e das microperfura es,sendo analisado um total de 100 indivíduos.A identifica o dos foraminíferos empregou microscópioestereoscópico e as fotomicrografias paraobserva o bioeros o nas carapa as foram obtidasem microscópio eletr nico de varredura. As associa esde foraminíferos bent nicos s o compostaspelas espécies de carapa as hialinas Ammoniatepida, Discorbis sp. e as espécies de carapa asporcelanosas foram Quinqueloculina laevigata,Quinqueloculina poeyana, Quinqueloculina seminulum,Quinqueloculina sp., Triloculina oblonga eTriloculina sp. A. tepida e Q. laevigata aparecemcom maior freqüência e maiores índices de microbioeros o.Nas espécies porcelanosas, as perfura estratam-se de formas alongadas ou circularesirregulares, ambas variando em espessura e diametro,enquanto nas hialinas, s o alongadas às vezesramificadas com diametros homogêneos, bem como,perfura es circulares a subcirculares irregulares emforma e tamanho. Bolivina sp, Triloculina sp. n oapresentaram marcas de bioeros o. As microperfura ess o atribuídas a microorganismos autotróficos.Agradecimentos ao Instituto Virtual de PaleontologiaIVP-FAPERJ, pelo suporte financeiro ao projeto e aoInstituto Militar de Engenharia, RJ, pela utiliza odo Microscópio Eletr nico.
Using Spatial Econometrics to Measure Ozone Pollution Externalities  [PDF]
C.-Y. Cynthia Lin
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.329130
Abstract: This paper summarizes my previous work in Lin (2010), in which I use spatial econometrics to analyze air pollution externalities. In Lin (2010), state-by-state source-receptor transfer coefficients that can be used as a basis for a location- differentiated permit system are estimated. Results affirm the importance of regional transport in determining local ozone air quality, although owing to non-monotonicities in ozone production the externality is not always negative. Because the origin of emissions matters, results also reject a non-spatially differentiated NOx cap and trade program as an appropriate mechanism for reducing ozone smog.
California’s Agriculture-Related Local Air Pollution Policy  [PDF]
C.-Y. Cynthia Lin
Journal of Environmental Protection (JEP) , 2013, DOI: 10.4236/jep.2013.48A1004
Abstract:

Air pollution is a critical environmental issue for California, which has some of the nation’s most polluted air basins and also the nation’s most stringent set of state and local air quality standards. This paper reviews my previous work in Lin (2011), in which I examine the effects of agriculture-related local regulations in California on air quality, as measured by the number of exceedances of the CO and NO2 standards, by exploiting the natural variation in policy among the different air districts in California. Agricultural burning policies and penalty fees reduce the pollution from CO. Other policies such as the prohibition on visible emission, fugitive dust, particulate matter, nitrogen and the reduction of animal matter are correlated with higher levels of CO. Regulations on orchard and citrus heaters have no significant effect on the number of exceedances of the CO and NO2 standards.

The Optimal Gasoline Tax for China  [PDF]
C.-Y. Cynthia Lin, Jieyin Zeng
Theoretical Economics Letters (TEL) , 2014, DOI: 10.4236/tel.2014.44037
Abstract:

Gasoline-powered vehicles produce many negative externalities including congestion, air pollution, global climate change, and accidents. A gasoline tax is perhaps the best policy to jointly address these externalities. This paper calculates the optimal gasoline tax for China. Using a model developed by Parry and Small [1] [2], we calculate the optimal adjusted Pigovian tax in China to be $1.58/gallon which is 2.65 times more than the current level. Of the externalities incorporated in this Pigovian tax, the congestion costs are taxed the most heavily, at $0.82/gallon, followed by local air pollution, accident externalities, and finally global climate change.

Genetic structure of Brazilian wild rice (Oryza glumaepatula Steud., Poaceae) populations analyzed using microsatellite markers
Karasawa, Marines M.G.;Vencovsky, Roland;Silva, Cynthia M.;Zucchi, Maria Imaculada;Oliveira, Giancarlo C.X.;Veasey, Elizabeth A.;
Genetics and Molecular Biology , 2007, DOI: 10.1590/S1415-47572007000300017
Abstract: knowledge of the genetic structure and diversity of natural populations is important in developing strategies for in situ and ex situ conservation. we used eight microsatellite loci to estimate genetic structure and investigate within and between population genetic variation in eleven brazilian wild rice (oryza glumaepatula) populations. the study showed the following genetic diversity parameters: average number of 3.1 alleles per locus; 77.3% polymorphic loci; 0.091 observed heterozygosity and 0.393 gene diversity. f-statistics detected by microsatellite loci were: fst = 0.491 (and rst = 0.608), fis = 0.780 and fit = 0.888. no population was in hardy-weinberg equilibrium. the estimated apparent outcrossing rate (0.143) indicated a predominance of self-fertilization. the gene flow values were low (nm = 0.259 and 0.161 for fst and rst, respectively). populations were spatially structured but without a correlation between genetic and geographic distances. five populations (pg-4, pg-2, pu-1, so-4, ne-18) were identified as priorities for conservation strategies. populations from the amazon biome showed heterogeneity with respect to intrapopulation diversity. the high level of genetic differentiation between populations and the high number of private alleles suggested that sampling should be carried out on a large number of o. glumaepatula populations for ex situ conservation purposes.
第1页/共309628条
每页显示 条


Home
Copyright © 2008-2020 Open Access Library. All rights reserved.