Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
1.
Front Public Health ; 12: 1268336, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38362215

RESUMO

Background: The life satisfaction and job performance of nursing professionals are affected by a multitude of factors, including work engagement, self-efficacy, and depression. The Job Demands-Resources (JD-R) model provides a theoretical framework to explore these relationships. Objective: Our study aimed to analyze the primary goal of this research, which is to examine the mediating role of work engagement in the relationship between depression, professional self-efficacy, job performance, and their impact on life satisfaction in nurses, using the JD-R theory as a guide. Methods: This cross-sectional study involved 579 participants aged between 21 to 57 years (M = 39, SD = 9.95). Mediation analysis was used to examine the influence of depression, self-efficacy, and job performance on work engagement, and in turn, its effect on life satisfaction. Results: Findings indicated that work engagement plays a crucial mediating role between depression, self-efficacy, job performance, and life satisfaction. Interventions to increase work engagement could assist nurses in better managing depression and improving their performance and life satisfaction. Conclusions: Our study highlights the need for workplace policies and strategies that foster work engagement and self-efficacy among nurses while effectively managing job demands to prevent depression. Moreover, these findings underscore the importance of the JD-R theory to understand and improve nurses' job satisfaction and performance, and suggest areas for future research, including exploring other potential factors and applying these findings across different contexts and cultures.


Assuntos
Recursos Humanos de Enfermagem Hospitalar , Estresse Ocupacional , Desempenho Profissional , Humanos , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Autoeficácia , Estudos Transversais , Depressão , Reorganização de Recursos Humanos , Engajamento no Trabalho
2.
J Environ Manage ; 354: 120266, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38350275

RESUMO

Managers need to trace social impacts and vulnerability caused by environmental change all the way to its driving forces to target key system components for intervention. However, most available scientific evidence deals with either the ecological impacts of direct drivers or the value of ecosystem benefits to people. Our matrix-based tool combines these types of evidence to make environmental management problems traceable through a structured yet flexible procedure. The tool consists of a series of matrices that sequentially link direct drivers of environmental change, landscapes, ecological conditions, benefits to people, and stakeholder types. Qualitative matrices result from the integration and synthesis of available evidence from literature reviews, and where data is scarce, these are used to elicit quantitative scores from expert opinion. Expert scoring of links and multiplication of matrices allow for estimating the impacts of each driver of environmental change on each stakeholder type and using this information as input to assess stakeholders' vulnerability through impact-influence diagrams. Applying the tool to the Argentine Gran Chaco, a globally threatened ecoregion, yielded a transparent and reliable picture of this data-scarce place, with important management implications. Tracing stakeholder impacts back to direct drivers confirmed that further encroachment of cleared areas around indigenous lands will increase the vulnerability of this social group. Also, assessing confidence levels for every social-ecological link suggested that incentivizing peasant farmers to restore natural forage supply represents a management opportunity to reverse degradation. Our tool makes interdisciplinary frameworks of linked ecological and social systems operational so managers can use the best available knowledge of a place and account for uncertainty to make environmental management decisions.


Assuntos
Ecossistema , Vulnerabilidade Social , Humanos , Meio Ambiente , Conservação dos Recursos Naturais/métodos
3.
Polymers (Basel) ; 15(4)2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36850185

RESUMO

Composites from polypropylene (PP) reinforced with hemp strands (HS) are prepared in the current work with the aim of deepening on the influence of this reinforcement on the impact performance of these specific composites. Despite all the research conducted in this field, the effect of this natural reinforcement on the absorbed energy during crack formation and propagation is not fully tackled in previous research works. From the methodology and samples' geometry, the results concluded that the quality of the interface has a noticeable role in the impact resistance of these materials. The interface strength, fiber dispersion and fiber pullout are the main contributors to crack formation, whereas fiber pullout is the main one responsible for crack propagation. Maximum values of absorbed energy were found for PP composites comprising 20-30 wt% of HS and 8 wt% of the coupling agent for the un-notched samples, whereas maximum absorbed energy values corresponded to PP composites with 40 wt% of HS and 4 wt% of coupling agent for the notched samples. The water-absorption behavior in different humid environments is also examined. From the kinetic study, the water diffusion followed a Fickean behavior showing low-diffusion coefficients, increasing with fiber content. This systematic investigation represents a contribution to the analysis of the potential of reinforcing conventional polymers with natural materials, as a strategy towards more sustainable development.

4.
Polymers (Basel) ; 15(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36679155

RESUMO

Agroforestry wastes are industrial byproducts available locally such as eucalyptus sawdust (EUC) and sugarcane bagasse (SCB). These byproducts can be used as lignocellulosic raw materials to produce high-value products. This study is a techno-economic analysis of four potential scenarios to produce polyhydroxybutyrate (PHB) and levulinic acid (LA) from hemicellulosic sugars by a fermentative pathway in a biomass waste biorefinery. Mass and energy balances were developed, and technical and economic assessments were carried out to obtain gas, char, and tar from residual solids from autohydrolysis treatment. It was determined that microbial culture could be an attractive option for added-value product production. More than 1500 t/year of PHB and 2600 t/year of LA could be obtained by the proposed pathways. Microbial and enzymatic conversion of LA from sugars could significantly improve energy consumption on the conversion strategy. The products from solid residual valorization (char and tar) are the most important for economic performance. Finally, a variation in specific variables could mean substantial improvements in the final indicators of the processes, reaching a higher NPV than USD 17 million.

5.
Polymers (Basel) ; 15(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36679252

RESUMO

The growing demand for plant fiber-reinforced composites offers new opportunities to compete against glass fiber (GF)-reinforced composites, but their performance must be assessed, revised, and improved as much as possible. This work reports on the production and the flexural strength of composites from polypropylene (PP) and hemp strands (20-50 wt.%), using maleic anhydride-grafted PP (MAPP) as a compatibilizer. A computational assessment of the reaction between cellulose and MAPP suggested the formation of only one ester bond per maleic anhydride unit as the most stable product. We determined the most favorable MAPP dosage to be 0.06 g per gram of fiber. The maximum enhancement in flexural strength that was attained with this proportion of MAPP was 148%, corresponding to the maximum fiber load. The modified rule of mixtures and the assumption of similar coupling factors for tensile and flexural strength allowed us to estimate the intrinsic flexural strength of hemp strands as 953 ± 116 MPa. While falling short of the values for sized GF (2415 MPa), the reinforcement efficiency parameter of the natural fibers (0.209) was found to be higher than that of GF (0.045).

6.
Talanta ; 251: 123766, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35940115

RESUMO

In this work, we present a microfluidic amperometric immunosensor for cancer biomarker claudin7 (CLD7) determination in circulating extracellular vesicles (EVs) as well as its validation in colorectal cancer (CC) patients. The device is based on synthetized nanosized MIL-125-NH2 particles, covalently anchored to the central channel of the microfluidic immunosensor. This nanomaterial was employed as efficient platform for anti-CLD7 monoclonal antibodies immobilization for specifically recognize and capture CLD7 in EVs samples. Afterwards, the amount of this trapped CLD7 was quantified by HRP-conjugated anti-CLD7-antibody. HRP reacted with its enzymatic substrate in a redox process which resulted in the appearance of a current whose magnitude was directly proportional to the level of CLD7 in the sample. This immunosensor, under optimum conditions, gave the limit of detection for CLD7 of 0.1 pg mL-1, with a wide linear range from 2 to 1000 pg mL-1. The results reported herein open up the use of porous open framework platforms for sensing applications for biomedicine and diagnosis.


Assuntos
Técnicas Biossensoriais , Neoplasias Colorretais , Nanoestruturas , Anticorpos Monoclonais , Biomarcadores Tumorais , Técnicas Biossensoriais/métodos , Neoplasias Colorretais/diagnóstico , Técnicas Eletroquímicas , Humanos , Imunoensaio/métodos , Limite de Detecção , Microfluídica/métodos , Porosidade
7.
J Prim Care Community Health ; 12: 21501327211051935, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34686079

RESUMO

OBJECTIVE: The COVID-19 protective motivation scale (EMP-COVID-19) has been developed for the assessment of protective motivation. This study aims to examine the psychometric properties of the EMP-COVID-19 for its application in the Peruvian community. METHODS: This is an observational, cross-sectional, instrumental design study, 483 adults (≥18 years) participated in the study, in 2 samples of 81 and 402 participants from the different macro-regions of Peru through an online survey using non-probabilistic sampling. Content validation was performed through expert judgment. Exploratory factor analysis (EFA) to evaluate the factor model of the EMP-COVID-19 was performed with the first sample. The confirmatory factor analysis (CFA) to verify the goodness of fit of the analysis found in the EFA was performed with the second sample. The examination of convergent and discriminant validity included peer evaluations of each EMP-COVID-19 dimension. Finally, the reliability of the instrument was evaluated using Cronbach's Alpha coefficient. RESULTS: The 3-factor related model presents better fit indices (CFI = 0.99; TLI = 0.99; RMSEA = 0.077 [90% CI 0.069-0.085]) versus a unidimensional model (CFI = 0.91; TLI = 0.90; RMSEA = 0.206 [90% CI 0.199-0.213]). The scale present convergent and discriminant validity in all the dimensions Threat Appraisal (AVE = .57), Coping Appraisal (AVE = .81), and Response Costs (AVE = .67). The Coping Appraisal (α = .97; ω = .97), Threat Appraisal (α = .88; ω = .74), and Response Costs (α = .80; ω = .76) dimensions were also found to have adequate reliability indices. CONCLUSIONS: The EMP-COVID-19 scale demonstrated adequate reliability and validity based on internal structure in the study sample.


Assuntos
COVID-19 , Motivação , Adulto , Estudos Transversais , Análise Fatorial , Humanos , Peru , Psicometria , Reprodutibilidade dos Testes , SARS-CoV-2 , Inquéritos e Questionários
8.
BMC Infect Dis ; 21(1): 769, 2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34364380

RESUMO

BACKGROUND: Dengue is one of the most important re-emerging viral diseases and the most common human arthropod-borne viral infection worldwide. Any of the four Dengue virus serotypes (DENV-1 to 4) can cause asymptomatic infections or clinical manifestations that range in severity from a mild, self-limited illness, to a severe disease characterized by a shock syndrome that can lead to death. Paraguay suffers periodic epidemic outbreaks of dengue since 1988 when the DENV-1 was introduced in the country. Epidemics caused by all four serotypes have been reported and the country. Although dengue is endemic in Paraguay, few studies have described the molecular epidemiology of DENV in the country, which is important to understand the local and global spread, as well as the evolution of this pathogen. METHODS: This was a cross-sectional study of a convenience sample. Suspected dengue patients of any age were recruited from the Emergency Laboratory of the Central Hospital of the Institute of Social Welfare, Asuncion, Paraguay, from February to June of 2011. A DENV antigen test was used to confirm the infection. The protein E gene sequences of isolated viruses were sequenced for phylogenetic analysis. RESULTS: Dengue was confirmed in 55.1% of the participants (n = 98/178). The most frequent clinical findings were fever, headache, and myalgia. Identity analyses of the protein E gene sequence of 56 viruses isolated showed the circulation of DENV-1 (n = 45) and DENV-2 (n = 11) in the Asuncion metropolitan area in 2011. Molecular epidemiology analyses suggest that DENV-1 was introduced into Paraguay from Argentina, while the DENV-2 from Brazil, replacing previous virus lineages. CONCLUSIONS: We have analyzed the molecular epidemiology of DENV-1 and DENV-2 isolated in Paraguay in 2011. We found strong evidence that DENV-1 was introduced into Paraguay from Argentina, while the DENV-2 from Brazil, replacing previous virus lineages. Molecular epidemiology studies are of great interest to analyze the dynamic of DENV spread, which are useful for early implementation of containment measures to reduce the risk of explosive epidemics caused by this virus.


Assuntos
Vírus da Dengue , Dengue , Epidemias , Estudos Transversais , Dengue/epidemiologia , Vírus da Dengue/genética , Genótipo , Humanos , Epidemiologia Molecular , Paraguai/epidemiologia , Filogenia
9.
Rev. peru. biol. (Impr.) ; 28(2): e20462, abr.-jun 2021. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1280513

RESUMO

Resumen En este trabajo se caracteriza y compara citogenéticamente Physalis peruviana "aguaymanto" de poblaciones cultivadas de la región Cajamarca: San Pablo, Celendín y Cajabamba. El número cromosómico más frecuente en las tres poblaciones fue 2n = 4x = 48 con frecuencias de 60, 50 y 34% en las poblaciones de San Pablo, Celendín y Cajabamba respectivamente. En menor frecuencia se encontró casos de aneuploidía somática. Los resultados permitieron distinguir cada población a partir de su fórmula cariotípica 17m+4sm+3t, 24m y 20m+2sm+2t que identifican a San Pablo, Celendín y Cajabamba respectivamente. Los cariotipos fueron caracterizados por la longitud total del complemento haploide (HCL) y los índices de simetría (S%), asimetría (A) y asimetría intra e intercromosómica (A1 y A2). El mayor valor de HCL se describió en San Pablo. Celendín presentó el mayor grado de simetría (S%=53.226 y A= 0.177), mientras que los cariotipos de San Pablo y Cajabamba fueron descritos como los más asimétricos. Se concluye que la condición más frecuente es la tetraploidía; aunque se evidencia diferente morfología cromosómica entre los cariotipos de las tres poblaciones.


Abstract In this work, we characterized cytogenetically Physalis peruviana "aguaymanto" and cultivated populations of the Cajamarca region: San Pablo, Celendín and Cajabamba are compared. The most frequent chromosomal number in the three populations was 2n = 4x = 48 with frequencies of 60, 50 and 34% in San Pablo, Celendín and Cajabamba respectively. Few cases of somatic aneuploidy were found. Our results let distinguish the populations by its karyotypic formula 17m + 4sm + 3t, 24m and 20m + 2sm + 2t (San Pablo, Celendín and Cajabamba respectively). Karyotypes were characterized by the total length of the haploid complement (HCL) and the indices of symmetry (S%), asymmetry (A) and intra and interchromosomal asymmetry (A1 and A2). The highest value of HCL was described in San Pablo. Celendín presented the highest degree of symmetry (S% = 53.226 and A = 0.177), while the karyotypes of San Pablo and Cajabamba were described as the most asymmetric. We concluded that the tetraploidy is most frequent condition; although there is evidence of different chromosomal morphology between the three populations.

11.
J Relig Health ; 60(2): 1248-1260, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33025332

RESUMO

This cross-sectional study examined the influence of knowledge and attitude on lifestyle practices (KAP) of the five dimensions of the Adventist Health Message (AHM5D). A sample of 1442 respondents was drawn from seven Seventh-day Adventist Churches in Metro Manila, Philippines. Hierarchical multiple regression showed that the social dimension of knowledge and the physical, spiritual, and social dimensions of attitude, significantly influenced the practices of AHM5D (ß = - .056, p = .037; ß = .236, p < .001; ß = .211, p < .001; ß = .145, p < .001, respectively), with r2 = .334. These findings suggest more effective interventions in the AHM5D promotion.


Assuntos
Estilo de Vida , Protestantismo , Atitude , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Filipinas
12.
Molecules ; 25(9)2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32380693

RESUMO

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.


Assuntos
Celulose/química , Polietileno/química , Saccharum/química , Varredura Diferencial de Calorimetria , Fósseis , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Impressão Tridimensional , Termogravimetria
13.
An. Fac. Med. (Perú) ; 81(2): 230-233, abr-jun 2020. graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1278271

RESUMO

RESUMEN Infodemia es la epidemia de información asociada con miedo, especulación y rumores, amplificada y transmitida rápidamente por las modernas tecnologías de la información y que afecta negativamente a la sociedad. Su asociación con la pandemia de la enfermedad por el coronavirus 2019 no es exclusiva, porque ya había sido descrita con la pandemia del Síndrome Respiratorio Agudo Grave por el coronavirus-1 en el año 2003. Esta información falsa o engañosa puede provocar una renuencia pública generalizada a adoptar medidas de control de infecciones bien fundamentadas promovidas por las autoridades de salud, y así retrasar la ejecución de las recomendaciones esenciales. La Organización Mundial de la Salud (OMS), en su afán de contrarrestarla, ha establecido la Red de Información de la OMS para Epidemias.


ABSTRACT Infodemia is the information epidemy associated to fear, speculation and rumors, amplified and transmitted rapidly by modern information technologies and that negatively affects society. Its association with the 2019 Coronavirus Disease pandemic is not exclusive, as it had already been described with the Coronavirus-1 Severe Acute Respiratory Syndrome pandemic in 2003. This false or misleading information may cause public reluctance widespread adoption of infection control measures promoted by health authorities, and thus delaying essential recomendations. The World Health Organization (WHO), in its eagerness to counteract, has established the WHO Information Network to Epidemics.

14.
Bioengineering (Basel) ; 6(3)2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31315280

RESUMO

Soda-ethanol pulps, prepared from a forestry residue pine sawdust, were treated according to high-consistency enzymatic fibrillation technology to manufacture nanocellulose. The obtained nanocellulose was characterized and used as ink for three-dimensional (3D) printing of various structures. It was also tested for its moisture sorption capacity and cytotoxicity, as preliminary tests for evaluating its suitability for wound dressing and similar applications. During the high-consistency enzymatic treatment it was found that only the treatment of the O2-delignified pine pulp resulted in fibrillation into nano-scale. For 3D printing trials, the material needed to be fluidized further. By 3D printing, it was possible to fabricate various structures from the high-consistency enzymatic nanocellulose. However, the water sorption capacity of the structures was lower than previously seen with porous nanocellulose structures, indicating that further optimization of the material is needed. The material was found not to be cytotoxic, thus showing potential as material, e.g., for wound dressings and for printing tissue models.

15.
Rev. odontol. mex ; 22(2): 88-94, abr.-jun. 2018. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-961598

RESUMO

Resumen: Los ruidos articulares constituyen junto a las restricciones mandibulares, los signos clásicos de los trastornos temporomandibulares (TTM) que pueden ir acompañados por sintomatología dolorosa. Su etiología multifactorial reconoce estrés emocional, traumatismo, dolor profundo, actividad parafuncional y problemas oclusales. El objetivo de este estudio descriptivo transversal fue determinar la frecuencia y tipos de ruidos articulares y su relación con las clases de Kennedy y la presencia o ausencia de sintomatología dolorosa. Se realizó exploración táctil y auscultación de la articulación temporomandibular (ATM) a 50 pacientes concurrentes a la Cátedra Clínica de Prótesis I curso. La incidencia de ruidos articulares fue del 48%: clics simples 48.15%, clics recíprocos 25.9%, pop 18.5%, y crepitaciones 7.4%. La anamnesis mostró presencia de dolor en un 14%. La coincidencia de ambos signos (dolor y ruido) coincidió en un 25%. Se presentó la alta incidencia de clics simples relacionada con la clase II de Kennedy.


Abstract: Mandibular noises, along with mandibular restrictions, constitute classical signs of temporomandibular joint disorders (TMJD) which can be accompanied with painful symptomatology. Its multifactorial etiology encompasses emotional stress, trauma, deep pain, parafunctional activity and occlusal problems. The aim of the present transversal and descriptive study was to determine frequency and types of articular noises and their relationship with Kennedy's classes, as well as presence or absence of painful symptomatology. A total of 50 patients attending the course of prosthesis clinical chair 1 were examined, they were subjected to tactile exploration and temporomandibular Joint (TMJ) auscultation. Frequency of articular noises was 48%, simple clicks 48.15%, reciprocal clicks 25.9%, pops 18.5% and crepitations 7.4%. Clinical history revealed presence of pain in 14% of cases. Coincidence of both signs (pain and noise) occurred in 25%. High incidence of simple clicks related to Kennedy's class II was observed.

16.
Vector Borne Zoonotic Dis ; 18(5): 266-272, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29652644

RESUMO

INTRODUCTION: Alphaviruses can produce febrile illness and encephalitis in dead-end hosts such as horses and humans. Within this genus, the Venezuelan Equine Encephalitis virus (VEEV) complex includes pathogenic epizootic subtypes and enzootic subtypes that are not pathogenic in horses (except subtype IE, Mexican strains), although they can cause febrile symptoms in humans. The Rio Negro virus (RNV-VEEV subtype VI) circulates in Argentina, where it was associated with undifferentiated febrile illness. Mayaro (MAYV) and Una (UNAV) viruses belong to a different group, the Semliki Forest virus complex, with confirmed circulation. OBJECTIVE: The present study aimed to determine RNV, MAYV, and UNAV seroprevalences by plaque reduction neutralization test in 652 samples of Paraguayan individuals mainly from the Central Department, between years 2012 and 2013. METHODS: Samples with antibodies titer >1:20 against RNV were also tested for Mosso das Pedras-subtype IF, subtype IAB, and Pixuna (PIXV)-subtype IV viruses that belongs to VEEV antigenic complex. RESULTS: The overall seroprevalence of RNV was 3.83%, and for UNAV it was 0.46%, and no neutralizing antibodies were detected against MAYV in the studied population. Two of the twenty-seven heterotypic samples were positive for PIXV. The 50.1% of neutralizing antibody titers against RNV were high (equal to or greater than 1/640), suggesting recent infections. The effect of age on the prevalence of RNV was negligible. CONCLUSIONS: These results bring new information about neglected alphaviruses in South America, and these data will serve as the basis for future studies of seroprevalence of other VEEV, and studies to search potential hosts and vectors of these viruses in the region.


Assuntos
Infecções por Alphavirus/epidemiologia , Alphavirus/imunologia , Anticorpos Antivirais/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alphavirus/genética , Alphavirus/isolamento & purificação , Infecções por Alphavirus/virologia , Criança , Pré-Escolar , Vírus da Encefalite Equina Venezuelana/genética , Vírus da Encefalite Equina Venezuelana/imunologia , Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Paraguai/epidemiologia , Estudos Soroepidemiológicos , Adulto Jovem
17.
Mem. Inst. Invest. Cienc. Salud (Impr.) ; 15(1): 7-15, abr. 2017. ilus
Artigo em Espanhol | LILACS, BDNPAR | ID: biblio-1008720

RESUMO

Los flavivirus son responsables de una considerable morbi-mortalidad a nivel mundial. Entre ellos, el virus del dengue (DENV) es causante de graves problemas de salud pública en Paraguay. El objetivo del estudio fue detectar infecciones por flavivirus a través de una reacción de RT-nested PCR genérica para flavivirus en 195 muestras de individuos con sospecha de dengue, negativos por el test inmunocromatográfico (antígeno NS1 ­ DENV), provenientes del área metropolitana de Asunción entre 2011 y 2013. Las muestras positivas para flavivirus fueron sometidas a dos reacciones de RT-nested PCRs específicas para DENV. El límite de detección (LD) para flavivirus fue de 0,2 UFP/reacción. En total 43/195 muestras fueron positivas para flavivirus. De estas, 38/43 (88,4%) correspondieron a DENV (6 DENV-1, 30 DENV-2 y 2 DENV-3). Además, 5/43 casos (11,6%) positivos para flavivirus fueron negativos para DENV por ambas reacciones específicas, pudiendo deberse a infecciones por otros flavivirus. Los resultados sugieren que la utilización de una reacción genérica seguida de otras reacciones específicas para DENV en casos febriles negativos para NS1 por el método inmunocromatográfico permitiría detectar más casos de infecciones por DENV y además, podría contribuir a la identificación de casos debido a infecciones por otros flavivirus.


Flaviviruses are responsible for considerable worldwide morbidity and mortality. Among them, the dengue virus (DENV) causes serious public health problems in Paraguay. The objective of the study was to detect flavivirus infections using a generic RT-nested -PCR in 195 samples of individuals with suspected dengue and negative for the inmunochromatographic test (NS1 antigen ­ DENV), from the metropolitan area of Asuncion between 2011 and 2013. The flavivirus-positive samples were subjected to two reactions of DENV-specific RT-nested PCRs. The detection limit (DL) for flavivirus was 0.2 PFU / reaction. In total, 43/195 samples were positive for flavivirus. Of them, 38/43 (88,4%) corresponded to DENV (6 DENV-1, 30 DENV-2 and 2 DENV-3). In addition, 5/43 cases (11.6%) positive for flavivirus were negative for DENV by both specific reactions, and may be infections caused by other flaviviruses. The results suggest that the use of a generic reaction followed by other DENV specific reactions in febrile negative cases for NS1 by the immunochromatographic method would allow the detection of more cases of DENV infections and could contribute to the identification of cases due to infections by others flaviviruses.


Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Infecções por Flavivirus/diagnóstico , Vírus da Dengue/isolamento & purificação , Flavivirus/isolamento & purificação , Paraguai , Estudos Transversais , Genoma Viral , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vírus da Dengue/genética , Vírus da Dengue/imunologia , Febre , Flavivirus/genética , Antígenos Virais/isolamento & purificação
18.
Carbohydr Polym ; 163: 20-27, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28267498

RESUMO

The present work aims to determine the influence of hemicellulose and lignin content in the production of lignocellulosic nanofibers (LCNF) from triticale straws. Triticale straws were digested and then gradually delignified, preserving as much hemicelluloses as possible. The obtained LCNF was characterized and used as paper strength additive, observing that hemicellulose and lignin have a key role on the final properties thereof, as well as on their reinforcing potential as paper additive, obtaining LCNF with the same paper reinforcing potential than CNF obtained by TEMPO ((2,2,6,6-Tetramethyl-piperidin-1-yl)oxyl) mediated oxidation.


Assuntos
Lignina/química , Nanofibras/química , Polissacarídeos/química , Triticale/química , Óxidos N-Cíclicos
19.
Environ Manage ; 58(5): 810-820, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27619944

RESUMO

Roads have important effects on wildlife, such as natural habitat fragmentation and degradation and direct killing of fauna, which leads to reductions in wildlife population size. We focused on a principal road in Northwest Argentina to test for the effect of seasonality and landscape features on the composition of road-killed wildlife. We conducted regularly scheduled road trips during the dry and wet seasons. We recorded the presence or absence of a vegetation curtain or hedge along the road. We measured land use by remote sensing in a 500 m buffer along the road. We compared the abundance of animals killed between seasons (dry and wet) for different taxonomic groups (mammals, birds and reptiles) and for different origins (domestic and native). We built linear mixed models to test the effect of landscape features on the abundance of killed animals. Two hundred and ninety-three individuals were killed, belonging to 35 species; 75.8 % were native and 24.2 % domestic species. The majority of animals killed were mid-sized mammals. More animals were killed during the dry season. The most important factors to explain the wildlife road-killing were the season and the proportion of agricultural landscape. The composition of the killed animals changed with the season. The proportion of agricultural landscape incremented the number of killed birds and mammals during both seasons, without affecting reptiles. The ratio of wild to domestic animals killed was dependent on the season. This study sets a precedent as the first in road ecology in Northwest Argentina and should be taken into account for road planning and regulation.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Animais Selvagens/crescimento & desenvolvimento , Ecossistema , Planejamento Ambiental , Acidentes de Trânsito/tendências , Agricultura , Animais , Animais Selvagens/classificação , Argentina , Aves/classificação , Aves/crescimento & desenvolvimento , Humanos , Mamíferos/classificação , Mamíferos/crescimento & desenvolvimento , Densidade Demográfica , Répteis/classificação , Répteis/crescimento & desenvolvimento , Estações do Ano
20.
Carbohydr Polym ; 139: 99-105, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-26794952

RESUMO

Nanofibrillated cellulose has been obtained from the cellulosic fraction of eucalyptus sawdust. The fractionation process involved the partial removal of hemicelluloses and lignin. CNF was obtained using TEMPO oxidation with NaOCl in basic medium followed by mechanical homogenization. The obtained CNF was subsequently used as a dry strength agent on unbleached unrefined eucalyptus pulp. The addition of 3, 6 and 9 wt.% of CNF increased lineally the tensile index of handsheets to about 55 N mg(-1) at 35°SR, compatible with papermachine runnability. The other mechanical properties also increased substantially, and porosity decreased moderately. The estimated specific surface and average diameter of these CNF were 60 m(2)g(-1), and of 41.0 nm, respectively. The addition of 9 wt.% of CNF produced an increase in mechanical strength, equivalent to that produced by PFI refining at 1600 revolutions.


Assuntos
Celulose/química , Eucalyptus , Nanofibras/química , Óxidos N-Cíclicos/química , Microscopia Eletrônica de Varredura , Nanofibras/ultraestrutura , Resistência à Tração , Madeira/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA