338 research outputs found
Effects of internal concentration and diffusivity profiles and onset of crust formation
The evaporation of droplets is an important process not only in industrial and scientific applications, but also in the airborne transmission of viruses and other infectious agents. We derive analytical and semi-analytical solutions of the coupled heat and mass diffusion equations within a spherical droplet and in the ambient vapor phase that describe the evaporation process of aqueous free droplets containing nonvolatile solutes. Our results demonstrate that the solute-induced water vapor-pressure reduction considerably slows down the evaporation process and dominates the solute-concentration dependence of the droplet evaporation time. The evaporation-induced enhanced solute concentration near the droplet surface, which is accounted for using a two-stage evaporation description, is found to further slow-down the drying process. On the other hand, the presence of solutes is found to produce a lower limit for the droplet size that can be reached by evaporation and, also, to reduce evaporation cooling of the droplet, which tend to decrease the evaporation time. Overall, the first two effects are dominant, meaning that the droplet evaporation time increases in the presence of solutes. Local variation of the water diffusivity inside the droplet near its surface, which is a consequence of the solute-concentration dependence of the diffusion coefficient, does not significantly change the evaporation time. Crust formation on the droplet surface increases the final equilibrium size of the droplet by producing a hollow spherical particle, the outer radius of which is determined as well
Viscous interfacial layer formation causes electroosmotic mobility reversal in monovalent electrolytes
We study the ion density, shear viscosity and electroosmotic mobility of an aqueous monovalent electrolyte at a charged solid surface using molecular dynamics simulations. Upon increasing the surface charge density, ions are displaced first from the diffuse layer to the outer Helmholtz layer, increasing its viscosity, and subsequently to the hydrodynamically stagnant inner Helmholtz layer. The ion redistribution causes both charge inversion and reversal of the electroosmotic mobility. Because of the surface-charge dependent interfacial hydrodynamic properties, however, the charge density of mobility reversal differs from the charge density of charge inversion, depending on the salt concentration and the chemical details of the ions and the surface. Mobility reversal cannot be described by an effective slip boundary condition alone – the spatial dependence of the viscosity is essential
Single beat determination of intraventricular systolic dyssynchrony in paitents with atrial fibrillation and systolic dysfunction
Background:: Atrial fibrillation (AF) is the most common clinically significant cardiac arrhythmia. However, diagnosis of intraventricular dyssynchrony in patients with AF is difficult due to beat-to-beat variation. Additionally, evaluation of mechanical dyssynchrony in the traditional method is based on average of 5 to 10 beats, which is exhausting and time consuming. Single-beat evaluation of a beat with equal subsequent cardiac cycles has been proposed as an accurate method in patients with AF.
Objectives:: We proposed to evaluate intraventricular mechanical dyssynchrony by measuring time-to-peak systolic velocity between basolateral and basoseptal segments (septum to lateral wall delay) using Tissue Doppler Study (TDI) by two different methods.
Materials and Methods:: 31 patient (68 ± 10.3 years) with heart failure (EF < 35%) and AF rhythm, R-R cycle length more than 500 msec were evaluated. We found a target beat in which preceding R-R (R-R1) to pre-preceding R-R (R-R2) ratio was 1(RR1/RR2 = 1) then measured the intraventricular dyssynchrony in that cycle. Intraventricular dyssynchrony was also determined and averaged for 8 consecutive cardiac cycles. The values at RR1/RR2 = 1 were compared with the average of intraventricular dyssynchrony in eight cycles and the relationship between dyssynchrony were evaluated by paired T-test, linear Pearson correlation (r2), linear regression analysis.
Results:: The average of dyssynchrony in eight cycles showed a positive correlation with dyssynchrony in target beat RR1/RR2 = 1. Average of dyssynchrony in target beat was 46.77 msec, and average of 8 cycle was = 47.701, (P value = 0.776, Pearson linear correlation 0.769).
Conclusions:: Measurement of intraventricular dyssynchromy in basoseptal and basolateral segments in AF and heart failure patients in a single beat with RR1/RR2 = 1 , were very similar to the average value of eight cardiac cycle
A Review of Various Methods of Management of Risk in the Field of Emergency Medicine
BACKGROUND: The main concept of risk management in the emergency department (ED) contains a broader meaning, so that; it's known as a sudden event or situation which would happen at an uncertain future that has some negative or positive impacts which could be called threat or opportunity respectively. However, the knowledge of risk management could cover the overall procedures involved with administering the planning of risk management, identification, investigation, monitoring and also step by step clinical examination. One of the main tools for preventing adversities is evaluating and management of possible risks.
AIM: One of the main objectives of the present study is recognising the most frequent types of the risk happening in the EDs. Moreover, the present study is trying to evaluate the possible risks which could happen among various ED sections.
METHODS: Six databases of EMBASE, HubMed, Cochrane Library, MEDLINE, PubMed, CHBD and Goggle scholar were chosen for discovering much-related articles from the year 2005 to 2019. A total number of 68 were chosen finally to be reviewed more precisely based on the main objective of the present study.
RESULTS: Precise planning, preparing sufficiently and conducting the process of continuous monitoring are needed for ensuring the fact that any possible risks could be managed through these planned strategies. On the other hand, by modifying the patients' beliefs, anticipations and the available social culture about the importance of risk management issue, the overall objective of the present study could be achieved at higher rates.
CONCLUSION: Moreover, because the potential of occurrence of risk in EDs is high and approximately more than half of them are fatal, more precise adequate systematic plans for management of them should result
Duchenne muscular dystrophy (DMD) protein- protein interaction mapping
ObjectiveDuchenne muscular dystrophy as one of the mortal diseases is prominent to study in terms of molecular investigation. In this study, the protein interaction map of this muscle-wasting condition is generated to gain a better knowledge of interactome profile of DMD.Materials & Methods Applying Cytoscape and String Database, the protein-protein interaction network was constructed and the gene ontology of the constructed network was analyzed for biological process, molecular function, and cell component annotations.ResultsThe results indicate that among 100 proteins that are related to DMD, Dystrophin, Utrophin, Caveolin 3, and Myogenic differentiation 1 play key roles in DMD network. In addition, the gene ontology analysis showed that regulation processes, kinase activity and sarcoplasmic reticulum are the highlighted biological processes, molecular function, and cell component enrichments respectively for the proteins related to DMD.  ConclusionIn conclusion, the central proteins and the enriched ontologies can be suggested as possible prominent agents in DMD; however, the validation studies may be required
Interaction network prediction and analysis of Anorexia Nervosa
ObjectivesAnorexia Nervosa (AN) as a mental condition is a common eating disorder among young women. This study aims to shed lights on molecular behavior of this serious disorder in terms of protein interacting profile to provide further insight about its complexity.Materials & MethodsThe AN related genes were extracted from STRING database and included in interactome via Cytoscape software. The central nodes of the network were enriched via gene ontology (GO) by ClueGO+CluePedia and the action relationship between the nodes were determined by CluePedia.ResultsSix genes including LEP, INS, POMC, GCG, SST, and ALB were introduced as hub-bottlenecks that among them LEP, INS, and POMC were the super hub-bottlenecks based on further analysis. Action map analysis showed prominent role of hubs relative to bottlenecks in the network. Regulation of behavior, regulation of carbohydrate biosynthetic process, and regulation of appetite are the top associated processes for the identified hub genes.ConclusionThe topological analysis proposed the five hub-bottlenecks as the most central genes in the network, these genes and their contributing biological terms may suggest additional importance in AN pathogenesis and thereby possible candidates for therapeutic usage. Â However, further studies is required to justify these findings.
Unveiling and unraveling aggregation and dispersion fallacies in group MCDM
Priorities in multi-criteria decision-making (MCDM) convey the relevance
preference of one criterion over another, which is usually reflected by
imposing the non-negativity and unit-sum constraints. The processing of such
priorities is different than other unconstrained data, but this point is often
neglected by researchers, which results in fallacious statistical analysis.
This article studies three prevalent fallacies in group MCDM along with
solutions based on compositional data analysis to avoid misusing statistical
operations. First, we use a compositional approach to aggregate the priorities
of a group of DMs and show that the outcome of the compositional analysis is
identical to the normalized geometric mean, meaning that the arithmetic mean
should be avoided. Furthermore, a new aggregation method is developed, which is
a robust surrogate for the geometric mean. We also discuss the errors in
computing measures of dispersion, including standard deviation and distance
functions. Discussing the fallacies in computing the standard deviation, we
provide a probabilistic criteria ranking by developing proper Bayesian tests,
where we calculate the extent to which a criterion is more important than
another. Finally, we explain the errors in computing the distance between
priorities, and a clustering algorithm is specially tailored based on proper
distance metrics
Propolis: A New Alternative for Root Canal Disinfection
Introduction: This study evaluated and compared colony forming units (CFUs) and minimum inhibitory concentrations (MICs) of calcium hydroxide and propolis as intracanal medicaments.Materials and Methods: Eighty human single-root and caries-free teeth were selected and divided into five groups. Crowns were removed. Root canals were then prepared in a step-back manner. The samples were then inoculated by Enterococcus (E.) faecalis and incubated for 21 days. Intracanal medications were applied including, calcium hydroxide (n=20), propolis (n=20), and ethanol (n=20). Two groups of 10 teeth were also used as the positive and negative controls. Microbiological sampling was performed utilizing a piezo-reamer drill after one week of incubation. The samples were plated and CFUs were counted after 48 hours. MICs of calcium hydroxide and propolis were measured by serial dilution and agar dilution methods, respectively. The statistical tests of ANOVA and Duncan post-hoc were used to compare different medications.Results: MICs and CFUs of propolis were dramatically less than calcium hydroxide. The difference between the groups was statistically significant (P<0.001).Conclusion: Our results reveal that propolis is an effective antimicrobial intracanal agent
Evaluation of skin response after erbium:yttrium–aluminum–garnet laser irradiation: a network analysis approach
Introduction: Application of laser in medicine and cosmetic purposes has raised grossly in recent years. There are contradictory finding about its side effects. In this research critical differentially expressed proteins after irradiation erbium:yttrium–aluminum–garnet (Er:YAG) laser on skin are investigated.Methods: Proteome data including 31 proteins were obtained from a proteomics investigation of laser irradiation, Er:YAG on female mouse skin that are published by Pan et al. The query proteins and 100 related ones were included in the protein-protein interaction (PPI) network. The central nodes were determined and all of nodes were included in action maps. Expression, activation, inhibition, binding, and reaction were considered in action plan.Results: Numbers of 16 proteins were recognized by STRING database and were included in the network. Except PHRF1, the other 15 query proteins were included in the main connected component of the constructed network. Ten central nodes of the network and ten numbers of top query proteins based on degree value were identified as central proteins of the network. All nodes of the network analyzed via action maps and the important acted nodes were determined as RPSA, GAPDH, TPT1, DCTN2, HSPB1, and PDIA3.Conclusion: Two balanced processes including cancer promotion and cancer prevention were after irradiation were identified
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