289 research outputs found
Molecular Dynamic Simulation Model for the Growth of Thin Films in The Structure Zone Model
A two dimensional molecular dynamic (atomistic) simulation model was used to
investigate the relationship between the nano-structure and the deposition parameters; namely,
substrate temperature, deposition rate, angle of incidence, surface roughness. Qualitative
agreements with the predictions of the structure zone model (SZM) and the theoretical results
of Srolovitze and coworkers (1988), as well as expectations through changes in the activated
processes during film growth due to changes in deposition parameters (Grovenor and
coworkers (1984)) are obtained. It is shown that by enhancing the atomic mobility (i.e.,
increasing the substrate temperature or/and lowering the deposition rate) films of higher
density with fewer voids are produced. By increasing the deposition angle, the nano-structure
of the film changes from a dense film with few voids, to a nano-structure with
columns/boundless inclined with the same angle ( β ) towards the incidence atoms with
elongated voids. The angle β increases with increasing the deposition angle (α ), and in
agreement with the tangent rule (Dirks and Leamy (1977)). The angle of bundles (or the angle
of the formation of the voids between atomic bundles), and columnar structure are caused by
shadowing effects. Results showed that β decreases slowly with increasing surface mobility
(i.e., increasing the substrate temperature or/and reducing the deposition rate).
In general, the model provides almost all predicted results and agrees well with
observation
CCSA: Conscious Neighborhood-based Crow Search Algorithm for Solving Global Optimization Problems
© 2019 Elsevier B.V. In this paper, a conscious neighborhood-based crow search algorithm (CCSA) is proposed for solving global optimization and engineering design problems. It is a successful improvement to tackle the imbalance search strategy and premature convergence problems of the crow search algorithm. CCSA introduces three new search strategies called neighborhood-based local search (NLS), non-neighborhood based global search (NGS) and wandering around based search (WAS) in order to improve the movement of crows in different search spaces. Moreover, a neighborhood concept is defined to select the movement strategy between NLS and NGS consciously, which enhances the balance between local and global search. The proposed CCSA is evaluated on several benchmark functions and four applied problems of engineering design. In all experiments, CCSA is compared by other state-of-the-art swarm intelligence algorithms: CSA, BA, CLPSO, GWO, EEGWO, WOA, KH, ABC, GABC, and Best-so-far ABC. The experimental and statistical results show that CCSA is very competitive especially for large-scale optimization problems, and it is significantly superior to the compared algorithms. Furthermore, the proposed algorithm also finds the best optimal solution for the applied problems of engineering design
Fuzzy Logic Based Direct Power Control of Induction Motor Drive
This paper is the design of an induction motor drive system that can be controlled using direct power control. First the possibilities of direct power control (DPC) of induction motors (IMs) fed by a voltage source inverter have been studied. Principles of this method have been separately evaluated. Also the drive system is more versatile due to its small size and low cost. Therefore it is advantageous to use the system where the speed is estimated by means of a control algorithm instead of measuring. This paper proposed one novel induction motor speed control system with fuzzy logic. The estimator was designed and simulated in Matlab/Simulink. Simulation result shows a good performance of speed estimator
The Founder Effect? -FXIII Deficiency in Southeast Iran: A Molecular Study Report
Background: Congenital factor XIII (FXIII) deficiency is an extremely rare bleeding disorder (RBD) with different clinical coagulation disorders and great impacts on the perioperative patient outcome. Its prevalence in Southeast Iran is approximately 4,000 times higher than the worldwide prevalence, with Trp187Arg (c.559T> C as the only causative mutation of FXIIID there. We investigated the founder effect of rs1742924, rs4960181, rs3778360 and rs4142290 using haplotype analysis to define the genetic phenomenon in this geographic region.
Materials and Methods: In a case-control study, 10 patients with FXIIID and 10 healthy individuals were assessed. Initially, Trp187Arg (c.559T> C) mutation was assessed in all study populations using a PCR-RFLP technique, then haplotype analysis was performed by assessing rs1742924, rs4960181, rs3778360 and rs4142290 polymorphisms. Data were analyzed using a two-proportion z-test.
Results: All patients were homozygote for Trp187Arg (c.559T>C), and this mutation was not observed in any form of homozygote or heterozygote in the control group. Polymorphisms in rs1742924, rs4960181, and rs377836 were homozygote (TT, GG, GG, respectively) and T, G, and G alleles distribution in cases and controls with significant difference (P<0.001, P<0.001, and P=0.01 respectively). Rs4142290 polymorphism showed no significant difference between patients and controls (P=0.3). Two types of haplotypes were observed in the case group, and haplotype number 1* was observed among 90% of them, while not observed in the control group.
Conclusion: It seems that founder effectors of haplotype number *1 have more antiquity versus other haplotypes, and probably founder effect is responsible for this high prevalence of FXIIID in the southeast of Iran
Utilization of Pharmacokinetic/Pharmacodynamic Modeling in Pharmacoepidemiological Studies:A Systematic Review on Antiarrhythmic and Glucose-Lowering Medicines
Introduction: In human pharmacology, there are two important scientific branches: clinical pharmacology and pharmacoepidemiology. Pharmacokinetic/pharmacodynamic (PK/PD) modeling is important in preclinical studies and randomized control trials. However, it is rarely used in pharmacoepidemiological studies on the effectiveness and medication safety where the target population is heterogeneous and followed for longer periods. The objective of this literature review was to investigate how far PK/PD modeling is utilized in observational studies on glucose-lowering and antiarrhythmic drugs. Method: A systematic literature search of MEDLINE, Embase, and Web of Science was conducted from January 2010 to 21 February 2020. To calculate the utilization of PK/PD modeling in observational studies, we followed two search strategies. In the first strategy, we screened a 1% random set from 95,672 studies on glucose-lowering and antiarrhythmic drugs on inclusion criteria. In the second strategy, we evaluated the percentage of studies in which PK/PD modeling techniques were utilized. Subsequently, we divided the total number of included studies in the second search strategy by the total number of eligible studies in the first search strategy. Results: The comprehensive search of databases and the manual search of included references yielded a total of 29 studies included in the qualitative synthesis of our systematic review. Nearly all 29 studies had utilized a PK model, whereas only two studies developed a PD model to evaluate the effectiveness of medications. In total, 16 out of 29 studies (55.1%) used a PK/PD model in the observational setting to study effect modification. The utilization of PK/PD modeling in observational studies was calculated as 0.42%. Conclusion: PK/PD modeling techniques were substantially underutilized in observational studies of antiarrhythmic and glucose-lowering drugs during the past decade
Health-related quality of life and medication adherence in elderly patients with epilepsy
© 2019 Polish Neurological Society. Objective. Considering the high prevalence of epilepsy in the elderly and the importance of maximising their quality of life (QoL), this study aimed to investigate the relationship between medication adherence and QoL, and the mediating effects of medication adherence on the association between serum antiepileptic drug (AED) level and seizure severity with QoL in elderly epileptics. Methods. In a longitudinal study, 766 elderly patients with epilepsy who were prescribed a minimum of one antiepileptic drug were selected by convenience sampling method. A Medication Adherence Report Scale (MARS-5) questionnaire was completed at the baseline. Seizure severity and QoL were assessed after six months using the Liverpool Seizure Severity Scale (LSSS) and the QoL in Epilepsy (QOLIE-31) questionnaires respectively. Serum level of AED was also measured at six-month follow-up. Results. Medication adherence was significantly correlated with both seizure severity (β = -0.33, p < 0.0001) and serum AED level (β = 0.29, p < 0.0001) after adjusting for demographic and clinical characteristics. Neither QoL nor its sub-classes were correlated with seizure severity. In addition, a significant correlation was not observed between serum AED level and QoL. However, medication adherence was significantly correlated with QoL (β = 0.30, p < 0.0001). The mediating effects of medication adherence on the association between serum AED level (Z = 3.39, p < 0.001) and seizure severity (Z = -3.47, p < 0.001) with QoL were supported by the Sobel test. Conclusion. This study demonstrates that medication adherence has a beneficial impact on QoL in elderly epileptics. Therefore, adherence to treatment should be monitored to improve their QoL
Effects of probiotic (Pediococcus acidilactici) on growth and survival of kutum (Rutilus kutum) fingerlings
In the present study effects of different levels of probiotic Pediococcus acidilactici, on growth performance and survival rate of Rutilus kutum fingerlings were investigated. Kutum fingerlings with a mean weight of 1±0.235 g were reared for 8 weeks in 500-l fiberglass tanks (15 fish per tank) with 4 diet treatments (3 replicates for each). Treatments included 1×10^9, 2:1×10^9, 3×10^9 CFU kg^-1 dry food and a control without probiotic. At the end of the study, specific growth rate (SGR) and survival rate (SR) were significantly higher in treatments supplemented with probiotic compared to the control (p<0.05), while the fish fed with probiotics showed lowest food conversion ratio (FCR) (p<0.05). The results indicated that the use of 3× 109 CFU kg^-1 dry food probiotics improved growth parameters and survival rate in R. kutum fingerlings
Reduction of the rate of hospitalization in patients with acute coronary syndrome: An action research
Background: Readmission of patients with Acute Coronary Syndrome (ACS) causes many problems for them and their family. This study aimed to improve the quality of care provided to patients with ACS and discover solutions to reduce the rate of readmission among them. Materials and Method: This participatory action research study was done based on Streubert and Carpenter approach. This study included 45 participants (31 patients and 14 stakeholders) and carried out in a hospital affiliated to Isfahan University of Medical Sciences, Iran, from 2013 to 2014. Solutions with high and moderate feasibility, flexibility, and suitability were implemented in each cycle until reaching <15 readmission rate. Data were analyzed using SPSS (V.16) and running descriptive and inferential statistics. Results: In this study, several actions were performed in each cycle such as assigning a free and 24-h telephone line was patients to contact nurses and face-to-face patient's education. Second cycle actions included active participation of all nurses in the education of patients and involvement of families in patient care. By carrying out the first action cycle, the readmission rate reached 35, which was not favorable. By completing the second action cycle, the readmission rate reached 12, which was desirable and significantly lower than the first cycle. Conclusion: Discovering possible solutions with the participation of stakeholders in therapeutic settings that have feasibility, flexibility, and suitability can lead to improved care quality and reduced readmission rate in patients with ACS, especially if the families of the patients also participate in action cycles. © 2021 Wolters Kluwer Medknow Publications. All rights reserved
Positive effect of low dose vitamin D supplementation on growth of fetal bones: A randomized prospective study
The effect of vitamin D supplementation on growth of fetal bones during pregnancy is unclear. The aim of this study was to assess the effect of low dose vitamin D supplementation during pregnancy on bony anthropometric aspects of the fetus. In this prospective randomized trial, 140 patients were divided into two equally matched groups according to age, 25(OH)D level, exercise, and dietary intake. Then 1000 IU per day vitamin D supplement was given to the intervention group while the control group received placebo. Then crown-rump length (CRL) and femur length (FL) during the first trimester and humerus and femur lengths as well as their proximal metaphyseal diameter (PMD), midshaft diameter (MSD) and distal metaphyseal diameter (DMD) in the second and third trimester were measured using ultrasonography technique. Finally, no significant difference was observed for CRL (p = 0.93). Although FL was not statistically significant in the first trimester (p = 0.54), its measurement in the intervention group and the control group in the second (28.87 ± 2.14 vs. 26.89 ± 2.08; p ≤0.001) and the third (65.31 ± 2.17 vs. 62.85 ± 1.94; p ≤0.001) trimesters was significantly different. Femoral PMD, MSD, and DMD measurement increased more in the intervention group in comparison with the control group with P values <0.05. HL measurement in the intervention group and the control group in the second (28.62 ± 1.94 vs. 27.23 ± 2.08; p ≤0.001) and the third (61.29 ± 2.84 vs. 59.85 ± 1.79; p ≤0.001) trimesters revealed significant differences. Humeral PMD, MSD, and DMD measurement increased in the intervention group in comparison with the control group with P values <0.001 for all. It is suggested to prescribe low dose vitamin D (1000 IU per day) from early pregnancy with possible increment in length and diameter of femur and humerus bones of the fetus
- …