46 research outputs found
Estilos de liderazgo y su influencia en la satisfacción laboral en los colaboradores de la municipalidad provincial de San Martín, 2019
El propósito de esta investigación es determinar de qué manera los estilos de liderazgo influyen en la satisfacción laboral de los colaboradores de la Municipalidad Provincial de San Martin, 2019. El tipo de investigación fue causal, de enfoque cuantitativo y de diseño no experimental, de corte transversal. La muestra estuvo constituida por 46 colaboradores, siendo 19 del género femenino y 27 del género masculino. Para el levantamiento de los datos se usó un instrumento que fue evaluado y validado por tres juicios de expertos, asimismo se obtuvo un Alfa de Cronbach de 0.701 para la satisfacción laboral y 0.806 para los estilos del liderazgo. Los resultados obtenidos mediante la correlación de Pearson de la investigación evidencian la existencia de una influencia positiva baja (Rho = 0,467**; p = 0,000) entre los estilos liderazgo y la satisfacción laboral. Esto quiere decir que a mayor implemento de los estilos de liderazgo le corresponde una mayor satisfacción laboral a los colaboradores de la MPSM. En conclusión, señalamos que existe influencia significativa entre estilos de liderazgo y satisfacción laboral.TARAPOTOEscuela Profesional de AdministraciónComportamiento organizaciona
Niveles de acrilamida en hojuelas de papas fritas comercializadas en Lima Metropolitana en el año 2018 y valores de referencia
Analiza los niveles de acrilamida en hojuela de papas fritas comercializadas en el año 2018 y comparar su situación frente a los valores de referencia establecidos internacionalmente. Fueron evaluadas 16 marcas de hojuelas de papas fritas (M1 a M16) provenientes de 9 productores. Fueron analizadas por cromatografía HPLC con columna HILIC, usando el método QUECHERS para su extracción y limpieza con factor de recuperación de 77,9%. Los niveles de acrilamida fueron expresados en μg/kg y comparados con los valores establecidos de la Unión Europea. Resultados: 12 de las 16 marcas, presentaron niveles promedio de acrilamida entre 868 y 2591 μg/kg; 2 de los 9 productores (fabricante de marcas M3, M6, M11 y M12) presentaron los más bajos niveles de acrilamida, con una media entre 386 y 540 μg/kg. Las muestras M1 y M8, de mayor distribución y probablemente mayor consumo, presentaron niveles de acrilamida >1033 μg/kg. Este trabajo encontró un promedio de contenido de acrilamida de 1234,18 μg/kg y que el 75 % de las marcas de hojuela de papas fritas comercializadas en Lima Metropolitana superaron los valores de referencia de 750 μg/kg
Prediction of the Limiting Flux and Its Correlation with the Reynolds Number during the Microfiltration of Skim Milk Using an Improved Model
Limiting flux (JL) determination is a critical issue for membrane processing. This work presents a modified exponential model for JL calculation, based on a previously published version. Our research focused on skim milk microfiltrations. The processing variables studied were the crossflow velocity (CFV), membrane hydraulic diameter (dh), temperature, and concentration factor, totaling 62 experimental runs. Results showed that, by adding a new parameter called minimum transmembrane pressure, the modified model not only improved the fit of the experimental data compared to the former version (R2 \u3e 97.00%), but also revealed the existence of a minimum transmembrane pressure required to obtain flux (J). This result is observed as a small shift to the right on J versus transmembrane pressure curves, and this shift increases with the flow velocity. This fact was reported in other investigations, but so far has gone uninvestigated. The JL predicted values were correlated with the Reynolds number (Re) for each dh tested. Results showed that for a same Re; JL increased as dh decreased; in a wide range of Re within the turbulent regime. Finally, from dimensionless correlations; a unique expression JL = f (Re, dh) was obtained; predicting satisfactorily JL (R2 = 84.11%) for the whole set of experiments
Endoscopic management of bile leaks after liver transplantation: An analysis of two high-volume transplant centers
Bile leak after liver transplantation (LT) is commonly treated with endoscopic retrograde cholangiopancreatography (ERCP); however, there are limited data regarding the optimal treatment strategy
Endoscopic management of bile leaks after liver transplantation: An analysis of two high- volume transplant centers
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166247/1/ueg2bf00797.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/166247/2/ueg2bf00797-sup-0001.pd
Viscoelastic relaxation: A mechanism to explain the decennial large surface displacements at the Laguna del Maule silicic volcanic complex
ilicic systems generate the most explosive eruptions on Earth. In contrast to basaltic systems, they can accumulate large volumes of magma without systematically erupting, confronting the classical interpretation that a volcano inflates when a magmatic intrusion occurs. Understanding the mechanisms of volcanic inflation and unrest is thus one of the most important challenges in volcanic risk assessment. Laguna del Maule (LdM) in the Southern Volcanic Zone (SVZ) of Chile, is one of the most active Holocene silicic complexes in the world and it has been inflating since 2007, accumulating 2 m of uplift without erupting. Several geophysical and geochemical studies conclude that a large crystal rich reservoir would be residing beneath LdM, in consistency with other multi-disciplinary studies showing that such crystal-rich reservoirs (“mush zones”) can be maintained beneath silicic volcanoes, fed by mafic magma recharge from below. Nevertheless, the mechanical state of such reservoirs remains unclear. Here, we characterize for the first time the mechanical properties of such a mush reservoir, able to promote large surface displacements such as those measured at LdM. Using a 3D finite element method we simulate a recharge of magma at the base of a crystal rich reservoir, by assuming an overpressurized source surrounded by a large viscoelastic shell. Inversion results show that this model fits the observed temporal and spatial evolution of ground displacements measured with InSAR data and GNSS data between 2007 and 2017. We interpret the temporal behavior of ground displacement at LdM as resulting from two contributions. A magma recharge occurred within the first 4 yr of the active inflation, followed by the viscous response of the large viscoelastic shell, set to a viscosity of 1017 Pas. Compared to a purely elastic solution, our model suggests that up to 50% of the accumulated surface displacement during the ten-year period can be explained by this viscous response, and predicts ongoing displacements 50 yr after the onset of inflation. This model agrees with geophysical and geochemical observations and offers a simple explanation of the temporal evolution of surface displacements. It further allows to reconsider the mechanical behavior of large partially crystallized domains in the upper crust; such significant transient stress transfer over large viscoelastic areas should thus be accounted for in other studies of silicic volcanic complexes
A multilevel dataset of microplastic abundance in the world’s upper ocean and the Laurentian Great Lakes
A total of 8218 pelagic microplastic samples from the world’s oceans were synthesized to create a dataset composed of raw, calibrated, processed, and gridded data which are made available to the public. The raw microplastic abundance data were obtained by different research projects using surface net tows or continuous seawater intake. Fibrous microplastics were removed from the calibrated dataset. Microplastic abundance which fluctuates due to vertical mixing under different oceanic conditions was standardized. An optimum interpolation method was used to create the gridded data; in total, there were 24.4 trillion pieces (8.2 × 104 ~ 57.8 × 104 tons) of microplastics in the world’s upper oceans
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Artemether nanocrystals: preparation and physical-chemical characterization
A nanotecnologia tem sido empregada como plataforma para o desenvolvimento de formas farmacêuticas com maior eficácia e segurança. A redução do tamanho de partículas em escala nanométrica permite conferir ao material propriedades inovadoras que têm sido exploradas em inúmeras aplicações, principalmente na indústria farmacêutica. Essa nova característica permite aumentar a biodisponibilidade oral de fármacos pouco solúveis em água. Os nanocristais apresentam como vantagens o aumento da solubilidade de saturação e da velocidade de dissolução. Tais propriedades são decorrentes da sua maior área superficial. Além disso, os nanocristais apresentam excelente adesão em superfícies biológicas. Essa característica resulta não apenas em uma melhor biodisponibilidade, mas também em redução na variação da biodisponibilidade de fármacos pouco solúveis em água. A malária é uma doença negligenciada prevalente nos países emergentes e afeta mais de 210 milhões de pessoas no mundo. Dentre as terapias medicamentosas para o tratamento da malária, o artemeter, derivado da artemisinina, apresenta potente atividade esquizonticida na fase hepática e na fase eritrocítica. Esse fármaco, amplamente utilizado no tratamento da malária, apresenta baixa solubilidade em água limitando sua biodisponibilidade oral. Tendo em vista a melhoria dessa característica, foram utilizados os métodos de moagem a alta energia, homogeneização a alta pressão e moagem via úmida, em escala reduzida para a obtenção de nanocristais. Esse último método foi aquele que permitiu a redução das partículas em escala nanométrica. O método por moagem a alta energia (MAE) revelou, nas condições experimentais do presente trabalho, 10% (D0,1) da população das partículas com diâmetro menor ou igual a 3,504 ± 0,19 µm, 50% (D0,5) menor ou igual a 14,225 ± 0,34 µm e 90% (D0,9) menor ou igual a 57,306 ± 5,72 µm. O diâmetro hidrodinâmico médio foi 25,01 ± 2,08 µm, sendo que o fator limitante na redução do tamanho da partícula foi a densidade do artemeter. Resultados similares foram obtidos empregando método de homogeneização a alta pressão. Diferentes tensoativos foram avaliados empregando o método selecionado, a moagem via úmida em escala reduzida. O agente estabilizante soluplus® foi aquele que favoreceu a redução do tamanho das partículas. Tal característica foi observada por meio de análise térmica. Essa análise permitiu determinar o grau de amorfização mínima, assim como, a presença de fortes ligações moleculares entre o fármaco e diferentes polímeros. A utilização do método por moagem via úmida em escala reduzida permitiu a obtenção de nanocristais de artemeter (formula R2-MUR), com diâmetro hidrodinâmico médio (DHM) igual a 342 ± 16,3 nm, índice de polidispersão (IP) de 0,23 ± 0,01 e distribuição monomodal de tamanho. Essa preparação otimizada foi obtida por meio de planejamento de experimentos por superfície de resposta tendo como variáreis independentes as concentrações de artemeter e do agente estabilizante (Soluplus®) além do tempo de moagem. As respostas foram o DHM e o IP, determinados utilizando espalhamento de luz dinâmica (DLS). Adicionalmente, as avaliações empregando calorimetria exploratória diferencial (DSC) e difração de raio X (DRX) revelaram que não houve alteração na estrutura cristalina do artemeter e interação entre o fármaco e os excipientes. O presente trabalho permitiu a obtenção de nanocristais de artemeter com solubilidade de saturação até 2,0 e 1,8 vezes maior em água e tampão McIlvaine (pH 2,5) respectivamente, comparada ao fármaco micronizado. Além disso, a preparação liofilizada foi estável após armazenamento por três meses a temperatura de 25 e 4 °C.Nanotechnology has been used as a platform for the development of pharmaceutical forms with greater effectiveness and safety. The reduction of particle size on a nanometric scale enables innovative properties to the material. These properties have been exploited in numerous applications, mainly in the pharmaceutical industry. This novel feature allows increasing the oral bioavailability of poorly water-soluble drugs. Nanocrystals have advantages such as increased saturation solubility and dissolution rate. These properties are due to their greater surface area. In addition, nanocrystals exhibit excellent adhesion on biological surfaces. This characteristic results not only in a better bioavailability but also in a reduction in the bioavailability variation of poorly water-soluble drugs. Malaria is a neglected disease prevalent in emerging countries and affects more than 210 million people worldwide. Among the medicinal therapies for the treatment of malaria, artemisinin-derived, artemether has potent schizonticidal activity in the liver and erythrocyte phases. This drug, widely used in the treatment of malaria, presents low solubility in water limiting its oral bioavailability. In order to improve this characteristic, the methods of high energy milling, high-pressure homogenization and wet milling on a reduced scale were used to obtain nanocrystals. This last method was the one that allowed the reduction of the artemether particles in nanoscale. The high energy milling method revealed, in the experimental conditions of the present study, 10% (D0,1) of the population of particles with a diameter less than or equal to 3,504 ± 0,19 µm, 50% (D0,5) less than or equal to 14.225 ± 0.34 µm and 90% (D0.9) less than or equal to 57.306 ± 5.72 µm. The mean hydrodynamic diameter was 25.01 ± 2.08 µm, being the limiting factor in the reduction of particle size the density of the artemether. Similar results were obtained using a high-pressure homogenization method. Different surfactants were evaluated using the selected method, wet milling on a reduced scale. The stabilizing agent soluplus® was the one that favored the reduction of the particle size. This characteristic was observed by thermal analysis. This analysis allowed determining the degree of minimum amorphization, as well as the presence of strong molecular bonds between the drug and some polymers. The wet milling on a reduced scale method allowed obtaining artemether nanocrystals (formula R2-MUR) with a mean hydrodynamic diameter (MHD) of 342 ± 16.3 nm, polydispersity index (PdI) of 0,23 ± 0.01 and monomodal distribution. These preparations were obtained through the response surface methodology (RSM) having as independent variables the concentrations of artemether and stabilizing agent (Soluplus®) and the milling time. MHD and PdI were performed using dynamic light scattering (DLS). In addition, evaluations using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) revealed that there was no change in the crystal structure of the artemether and interaction between the drug and the excipients. The present work allowed obtaining of artemether nanocrystals with saturation solubility up to 2.0 and 1.8 times higher in water medium and McIlvaine buffer (pH 2.5), respectively, compared to the micronized drug. In addition, the lyophilized preparation was stable after storage for three months at 25 and 4 ° C