scholarly journals Methodology for the design of a multilayer polymeric membrane system with potential use in hemofiltration

2021 ◽  
pp. 20-26
Author(s):  
Lourdes Nohemi Nuñez-Hernández ◽  
María Cristina Kantun-Uicab ◽  
Laura Maryela Pérez-Castañeda ◽  
Jorge Sergio Téllez-Martínez
Keyword(s):  
Complex Analysis ◽  
Membrane System ◽  
Polymeric Membrane ◽  
Porous Membranes ◽  
Flow Conditions ◽  
Coupling System ◽  
Case Rate ◽  
Extensive Flow ◽  
Potential Use ◽  
Made In

Chronic kidney disease is generally complicated by poor care or by ignoring it. Among the causes that influence these conditions are obesity, diabetes, smoking, or genetic inheritance. Coordinated efforts are currently being made in multiple countries to control a strong case rate. The clinical techniques of treatment rely on the efficiency of blood purification (function that´s done by kidneys in organisms). Therefore, there is great interest in the development of devices that accomplish this function. Hemofiltration through porous membranes is an efficient process, but the flow conditions in a microchannel system can be complex. Analysis of blood flow in a parameterized conduit arrangement shows streams with desired trajectories, others are held back (stagnant), and others return to the stream from which it´s separated. In addition, the friction conditions and the reduction of the area drastically reduce the movement of the fluid, promoting clogging and consequently the inhibition of filtering. Based on these simulation results, it was proposed that the membrane coupling system could be modified to eliminate extensive flow in conduits generating a new concept of separation through a threshold.

scholarly journals An approach to the modeling of a virtual thermal manikin

2014 ◽  
Vol 18 (4) ◽  
pp. 1413-1423 ◽  
Author(s):  
Dragan Ruzic ◽  
Sinisa Bikic
Keyword(s):  
Turbulence Models ◽  
Thermal Conditions ◽  
Heat Fluxes ◽  
Thermal Manikin ◽  
Flow Conditions ◽  
Body Segments ◽  
Nominal Size ◽  
Natural Flow ◽  
Good Agreement ◽  
Made In

The aim of the research described in this paper, is to make a virtual thermal manikin that would be simple, but also robust and reliable. The virtual thermal manikin was made in order to investigate thermal conditions inside vehicle cabins. The main parameters of the presented numerical model that were investigated in this paper are mesh characteristics and turbulence models. Heat fluxes on the manikin's body segments obtained from the simulations were compared with published results, from three different experiments done on physical thermal manikins. The presented virtual thermal manikin, meshed with surface elements of 0.035 m in nominal size (around 13,600 surface elements) and in conjunction with the two-layer RANS Realizable k-? turbulence model, had generally good agreement with experimental data in both forced and natural flow conditions.

scholarly journals miRNAs as Biomarkers in Disease: Latest Findings Regarding Their Role in Diagnosis and Prognosis

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 276 ◽  
Author(s):  
Carmen Elena Condrat ◽  
Dana Claudia Thompson ◽  
Madalina Gabriela Barbu ◽  
Oana Larisa Bugnar ◽  
Andreea Boboc ◽  
...  
Keyword(s):  
High Specificity ◽  
Research Field ◽  
Therapeutic Interventions ◽  
Protein Levels ◽  
Diagnosis And Prognosis ◽  
Specificity And Sensitivity ◽  
Online Databases ◽  
Patient Profiles ◽  
Potential Use ◽  
Made In

MicroRNAs (miRNAs) represent a class of small, non-coding RNAs with the main roles of regulating mRNA through its degradation and adjusting protein levels. In recent years, extraordinary progress has been made in terms of identifying the origin and exact functions of miRNA, focusing on their potential use in both the research and the clinical field. This review aims at improving the current understanding of these molecules and their applicability in the medical field. A thorough analysis of the literature consulting resources available in online databases such as NCBI, PubMed, Medline, ScienceDirect, and UpToDate was performed. There is promising evidence that in spite of the lack of standardized protocols regarding the use of miRNAs in current clinical practice, they constitute a reliable tool for future use. These molecules meet most of the required criteria for being an ideal biomarker, such as accessibility, high specificity, and sensitivity. Despite present limitations, miRNAs as biomarkers for various conditions remain an impressive research field. As current techniques evolve, we anticipate that miRNAs will become a routine approach in the development of personalized patient profiles, thus permitting more specific therapeutic interventions.

Potential use of nanotechnology in sustainable and ‘smart’ agriculture: advancements made in the last decade

2020 ◽  
Vol 14 (5) ◽  
pp. 505-513 ◽  
Author(s):  
Ranjita Ghosh Moulick ◽  
Sumistha Das ◽  
Nitai Debnath ◽  
Kaustav Bandyopadhyay
Keyword(s):  
Smart Agriculture ◽  
Potential Use ◽  
Made In

Utilisation d'éléments structuraux en aluminium dans les ponts routiers : Étude économique et structurale

2001 ◽  
Vol 28 (6) ◽  
pp. 1029-1040 ◽  
Author(s):  
Carol Roy ◽  
Denis Beaulieu ◽  
Josée Bastien
Keyword(s):  
Cost Analysis ◽  
Bridge Deck ◽  
Concrete Slab ◽  
Second Step ◽  
Structural System ◽  
Analysis Study ◽  
Simple Repair ◽  
Potential Use ◽  
Economic Standpoint ◽  
Made In

The study presented in this paper is part of a project aiming at evaluating the potential use of aluminum in structures. The types of intervention could range from a simple repair or a reinforcement involving structural aluminum, the replacement of a used bridge deck by an aluminum deck, to the construction of a new bridge made in full or in part of aluminum. It is this latter type of intervention that justified a research project, the results of which are presented in this article. The first step involves identifying the most advantageous type of aluminum structural system from a structural standpoint as well as an economic standpoint. This step includes the analysis and partial design of 40 girder- or truss-type road bridges, spanning 15 and 35 m, supporting either an active concrete slab or an aluminum deck. These studies have shown that bridges built using a Pratt-type truss and an active concrete slab provided the best results. It is also shown that some calculation criteria, such as vibration, deflection, and fatigue criteria limited the extensive use of aluminum in bridges. In the second step, nine bridges are more comprehensively analysed and designed, based on the standards used in North America, and three are fully designed, including the connexions, in order to realize a cost analysis study that is as accurate as possible. Special attention is given to vibration and fatigue problems as well as to the details related to connexions calculation. The study concludes that the development of an aluminum-only medium span road bridge system is a non-viable project in the short to mid term from a structural standpoint as well as an economic standpoint, and it makes recommendations on the use of aluminum decks and on the continuation of the work.Key words: aluminum, analysis, bridges, connexions, design, fatigue, standards, vibration.[Journal translation]

Dynamics of Drift and Microdistribution of Two Mayfly Populations: A Predictive Model

1987 ◽  
Vol 44 (4) ◽  
pp. 832-845 ◽  
Author(s):  
Jan J. H. Ciborowski
Keyword(s):  
Large Scale ◽  
Distribution Patterns ◽  
Flow Conditions ◽  
Transition Matrices ◽  
Permanent Displacement ◽  
Redistribution Mechanism ◽  
Baetis Tricaudatus ◽  
Stable Flow ◽  
Downstream Movement ◽  
Made In

A model is derived to predict changes in larval microdistribution of Ephemerella inermis Eaton and Baetis tricaudatus Dodds (Ephemeroptera) that result from drift. Transport by drift was assumed to be a Markov process. Estimates of departure from the substrate, downstream movement, and lateral transport were combined to produce transition matrices from which changes in microdistribution, magnitude of drift, and mean daily downstream displacement of live and dead animals were determined. Predictions from the model were compared with observations made in a river similar in composition to the area modelled. There were marked differences between expected drift of living versus dead animals; estimates for drift of living animals corresponded most closely to values observed in the field. Predicted drift either corresponded to or was less than observed levels. Observed changes in benthic microdistribution were minimal, but the model predicted large-scale relocation of animals toward river margins. Thus, magnitude and spatial pattern of drift could be adequately modelled but benthic distribution could not. Drift is an important redistribution mechanism but animals must have a complementary ability to actively travel towards the river center to maintain constant benthic distribution patterns. Inhibition of movement during floods should produce increased abundance at margins. During stable flow conditions, drift and benthic activity probably act together to produce and maintain microdistributional patterns among vagile organisms. In contrast, drift of invertebrates possessing poor locomotory ability probably reflects larger-scale, permanent displacement events that are a normal aspect of development, or the outcome of aggressive interactions.

Modeling the Onset of Gas Entrainment in a Single Downward Discharge From a Stratified Gas-Liquid Region With Liquid Crossflow

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
R. C. Bowden ◽  
I. G. Hassan
Keyword(s):  
Experimental Data ◽  
Froude Number ◽  
Liquid Region ◽  
Flow Conditions ◽  
Critical Height ◽  
High Discharge ◽  
Gas Entrainment ◽  
Model Predictions ◽  
Pipe Inlet ◽  
Made In

The critical height at the onset of gas entrainment, in a single downward oriented discharge from a stratified gas-liquid region with liquid crossflow, was modeled. The assumptions made in the development of the model reduced the problem to that of a potential flow. The discharge was modeled as a point-sink while the crossflow was said to be uniform at the main pipe inlet. The potential function was determined from a superposition of known solutions for a point-sink and uniform flow. The resulting system of three equations demonstrated that the flow field was dominated by the discharge and crossflow Froude numbers. The system was solved numerically and provided a relationship between the geometry, flow conditions, dip location, and critical height. The model predicted that the critical height increased with the discharge Froude number and decreased with the crossflow Froude number. With no imposed crossflow, the model prediction demonstrated agreement with transient and quasisteady experimental data to within ±30%. Existing experimental correlations showed inconsistent crossflow effects on the critical height and disagreed with the model predictions at high discharge Froude numbers.

scholarly journals Lysine Acetylation: Elucidating the Components of an Emerging Global Signaling Pathway in Trypanosomes

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Victoria Lucia Alonso ◽  
Esteban Carlos Serra
Keyword(s):  
Mass Spectrometry ◽  
Rational Design ◽  
High Resolution Mass Spectrometry ◽  
Lysine Acetylation ◽  
Nuclear Compartment ◽  
The Past ◽  
Regulatory Functions ◽  
Potential Use ◽  
Resolution Mass ◽  
Made In

In the past ten years the number of acetylated proteins reported in literature grew exponentially. Several authors have proposed that acetylation might be a key component in most eukaryotic signaling pathways, as important as phosphorylation. The enzymes involved in this process are starting to emerge; acetyltransferases and deacetylases are found inside and outside the nuclear compartment and have different regulatory functions. In trypanosomatids several of these enzymes have been described and are postulated to be novel antiparasitic targets for the rational design of drugs. In this paper we overview the most important known acetylated proteins and the advances made in the identification of new acetylated proteins using high-resolution mass spectrometry. Also, we summarize what is known so far about the acetyltransferases and deacetylases in eukaryotes, focusing on trypanosomes and their potential use as chemotherapeutic targets.

scholarly journals Razones y maravedís: una mirada crítica a los negocios del ferrocarril en España (1844-1943)

2018 ◽  
pp. 522
Author(s):  
Domingo Cuéllar
Keyword(s):  
Economic History ◽  
Complex Analysis ◽  
Conflicts Of Interest ◽  
Regulatory State ◽  
Private Companies ◽  
Long Term Study ◽  
State Financing ◽  
La Red ◽  
Made In

Resumen: El negocio de los ferrocarriles en España en la etapa del sistema de concesiones a compañías privadas abarcó un largo periodo que se aproximó al siglo. La primera línea puesta en explotación lo hizo en 1848 y la nacionalización de toda la red de vía ancha se decretó en 1941. El estudio en el largo plazo del desarrollo de esas empresas y su relación con el Estado regulador del sistema tiene tres periodos claves bien diferenciados, aunque muy desiguales en su duración: la concesión, la explotación y el rescate.En cada una de esas etapas se tejieron relaciones de complejo análisis y se presentaron escenarios con evidentes conflictos de intereses entre sus protagonistas, se dieron desembolsos no siempre justificados de los caudales públicos, o se promulgaron normas que no ayudaron a un funcionamiento equilibrado del sistema. El ferrocarril siempre ha estado en el punto de mira, lo que nos obliga a hacer un análisis crítico de su historia.Palabras clave: Historia económica, Ferrocarriles, Empresas, Estado, Financiación Historia contemporánea de España, Historia de Cataluña.Abstract: The business of the railways in Spain in the stage of the system of concessions to private companies covered a long period that approached the century. The first line put into operation was made in 1848 and the nationalization of the entire wide-track network was enacted in 1941. The long-term study of the development of these companies and their relationship with the regulatory state of the system has three key periods differentiated, although very unequal in their duration: the concession, the exploitation and the rescue.In each of these stages, it’s spun relationships with complex analysis and it’s made scenarios with obvious conflicts of interest between their protagonists, outlays not always justified from public flows, or rules were promulgated that did not help a balanced functioning of the system. The railway has always been in the spotlight, which forces us to make a critical analysis of its history.Keywords: Economic History, Railways, Companies, State, Financing.

Segmental microvascular permeability in ischemia-reperfusion injury in rat lung

1999 ◽  
Vol 276 (6) ◽  
pp. L958-L960 ◽  
Author(s):  
Pavel L. Khimenko ◽  
Aubrey E. Taylor
Keyword(s):  
Airway Pressure ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Venous Pressure ◽  
Microvascular Permeability ◽  
Rat Lung ◽  
Flow Conditions ◽  
Highly Correlated ◽  
Total Membrane ◽  
Made In

Segmental microvascular permeabilities were measured using pre- and postalveolar vessel capillary filtration coefficient ( K fc) values (ml ⋅ min−1 ⋅ cmH2O−1 ⋅ 100 g−1) in isolated rat lungs subjected to ischemia-reperfusion (I/R). Total K fc values measured in flowing and nonflowing lungs were highly correlated ( r = 0.98, P < 0.0001). K fc values were then measured in another group of lungs under no-flow conditions when airway pressure was increased to 20 cmH2O and either the arterial or venous pressure was elevated to 7–8 cmH2O to measure the prealveolar and postalveolar K fc values. Control total and postalveolar K fc values were 0.0225 ± 0.001 and 0.0219 ± 0.001 ml ⋅ min−1 ⋅ cmH2O−1 ⋅ 100 g−1, respectively, and the prealveolar permeability was extremely small (0.00003 ± 0.00005 ml ⋅ min−1 ⋅ cmH2O−1 ⋅ 100 g−1). K fc values were again made in nonflowing lungs that had been subjected to 45 min of ischemia followed by 30 min of reperfusion. After I/R, the total membrane K fc increased 10-fold to 0.2597 ± 0.006 ml ⋅ min−1 ⋅ cmH2O−1 ⋅ 100 g−1, the prealveolar K fc increased to 0.0677 ± 0.003 ml ⋅ min−1 ⋅ cmH2O−1 ⋅ 100 g−1, and the postalveolar K fc increased to 0.1354 ± 0.008 ml ⋅ min−1 ⋅ cmH2O−1 ⋅ 100 g−1 ( P < 0.05 for all I/R values). These data indicate that normal solvent microvascular permeability was predominantly postalveolar, and after I/R damage, the postalveolar (venular) permeability comprised 52% of the total, whereas the prealveolar and alveolar vessels comprised only 27 and 23%, respectively, of the total K fc.

scholarly journals New Frontiers on Human Safe Insecticides and Fungicides: An Opinion on Trehalase Inhibitors

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3013 ◽  
Author(s):  
Camilla Matassini ◽  
Camilla Parmeggiani ◽  
Francesca Cardona
Keyword(s):  
Natural Compounds ◽  
Green Economy ◽  
Natural Complex ◽  
The Past ◽  
The Future ◽  
Hydrophilic Compounds ◽  
Potential Use ◽  
Made In

In the era of green economy, trehalase inhibitors represent a valuable chance to develop non-toxic pesticides, being hydrophilic compounds that do not persist in the environment. The lesson on this topic that we learned from the past can be of great help in the research on new specific green pesticides. This review aims to describe the efforts made in the last 50 years in the evaluation of natural compounds and their analogues as trehalase inhibitors, in view of their potential use as insecticides and fungicides. Specifically, we analyzed trehalase inhibitors based on sugars and sugar mimics, focusing on those showing good inhibition properties towards insect trehalases. Despite their attractiveness as a target, up to now there are no trehalase inhibitors that have been developed as commercial insecticides. Although natural complex pseudo di- and trisaccharides were firstly studied to this aim, iminosugars look to be more promising, showing an excellent specificity profile towards insect trehalases. The results reported here represent an overview and a discussion of the best candidates which may lead to the development of an effective insecticide in the future.

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