Alternative heart assistance pump

2021 Spring.Includes bibliographical references.On average, the human heart beats around 115,000, and pumps around 2,000 gallons of blood daily. This essential organ may undergo systolic or diastolic dysfunction in which the heart cannot properly contract or relax, respectively. To help hearts pump effectively should these types of failures occur, ventricular assist devices (VAD) are implemented as a temporary or permanent solution. The most common VAD is the left ventricular assist device (LVAD) which supports the left ventricle in pumping the oxygen-rich blood from the heart to the aorta, and ultimately to the rest of the body. Although current VADs are an important treatment for advanced heart failure, generally VADS come with many complications and issues after implantation. These complications include incidents of hemolysis (tearing of the blood cells), thrombosis (clotting of the blood), bleeding (especially in the gastrointestinal tract), and infection at the driveline site. Specifically, the current continuous flow pumps are associated with a much higher incidence of gastrointestinal bleeding, myocardial perfusion, kidney problems, among others, compared with the earlier generation pulsatile pumps. However, the presence of several moving mechanical components made the pulsatile pumps less durable, bulky, and prone to malfunction, ultimately leading to favor toward continuous flow designs. The goal of the present study is to develop a novel heart assist pump, overcoming drawbacks to current commercially available pumps, by improving hemodynamic (blood flow) performance, pulsatility, and eliminating bleeding disorders. Our design will overcome the current pumps which suffer from non-physiological flow, and blood damage. The impact of this work goes beyond heart assist devices and would be applicable to other blood pumps. The fundamental biological and physical principles of designing a blood pump will be reviewed in chapter one. In addition, recent studies on current LVADs and the motivation behind these studies will also be discussed. Then, the idea of using a contractive tubular heart as an alternative pump will be presented in chapter two. To understand the pumping mechanism of the tubular heart, a detailed study on the embryonic heart is presented in this chapter. Subsequently, the effect of flow forces on blood cells will be studied in chapter 3. Moreover, the relation between flow regime and bleeding disorders have been studied in the same chapter. A discussion of our design, including the pump design, testing set up, experimental results will be presented in chapter 4. Finally, the limitations of the present study and future work will be presented in chapter 5

INVESTIGATING THE EFFECT OF BRAND CUSTOMER EXPERIENCE ON CUSTOMER REUSE OF THE SERVICE THROUGH TRUST IN AYANDEH BANK

Abstract. One of the concepts that have recently attracted the attention of experts in the field of consumer behavior is brand perception. This concept refers to experiences that derived from the complex customer interactions with the trust. Present research aims to Investigating the effect of brand perception on customers reuse of services in Ayandeh Bank. Required information was adapted by the questionnaire-based on research model and was responded by 384 Ayandeh Bank customers. The Structural equation modeling was used to analyze data and reliability had been confirmed. The result of this study confirmed that Brand perception has effect on customers reuse of services, with the trust. At the end based on research findings recommendations were presented.Keywords: Brand perception - customers reuse of services – Trust.

On the Design and Testing of Authorization Systems

Authorization deals with the specification and management of accesses principals have to resources. In the design of an authorization system, sometimes we just implement the accessenforcement without having a precise semantics for it. In this dissertation we show that, there exists a precise semantics that improves the efficiency of access-enforcement over the accessenforcement without precise semantics. We present an algorithm to produce an Access Control List (ACL), in a particular authorization system for version control syatems called gitolite, and we compare the implementation of our algorithm against the implementation that is already being used. As another design problem, we consider least-restrictive enforcement of the Chinese Wall security policy. We show that there exists a least-restrictive enforcement of the Chinese Wall Security Policy. Our approach to proving the thesis is by construction; we present an enforcement that is least-restrictive. We also prove that such an enforcement mechanism cannot be subjectindependent. We also propose a methodology that tests the implementation of an authorization system to check whether it has properties of interest. The properties may be considered to be held in the design of an authorization system, but they are not held in the implementation. We show that there exist authorization systems that do not have the properties of interest

The Effect of Chronic Administration of Buspirone on 6-Hydroxydopamine-Induced Catalepsy in Rats

Purpose: Several evidences show that serotonergic neurons play a role in the regulation of movements executed by the basal ganglia. Recently we have reported that single dose of buspirone improved 6-hydroxydopamine (6-OHDA) and haloperidol-induced catalepsy. This study is aimed to investigate effect of chronic intraperitoneal (i.p.) administration of buspirone on 6-OHDA-induced catalepsy in male Wistar rats. Methods: Catalepsy was induced by unilateral infusion of 6-OHDA (8 μg/2 μl/rat) into the central region of the SNc and was assayed by the bar-test method 5, 60, 120 and 180 min after drugs administration in 10th day. The effect of buspirone (0.5, 1 and 2 mg/kg, i.p. for 10 days) was assessed in 6-OHDA-lesioned rats. Results: The results showed that chronic injection of buspirone (0.5, 1 and 2 mg/kg, i.p. for 10 days) decreased catalepsy when compared with the control group. The best anticataleptic effect was observed at the dose of 1 mg/kg. The catalepsy-improving effect of buspirone was reversed by 1-(2-methoxyphenyl)- 4-[4-(2-phthalimido) butyl]piperazine hydrobromide (NAN-190), 0.5 mg/kg, i.p.,as a 5-HT1A receptor antagonist. Conclusion: Our study indicates that chronic administration of buspirone improves catalepsy in a 6-OHDA-induced animal model of parkinson's disease (PD). We also suggest that buspirone may be used as an adjuvant therapy to increase effectiveness of antiparkinsonian drugs. In order to prove this hypothesis, further clinical studies should be done

Investigation of Correlation between Entrepreneurial Strategies and Resistance Economics Policy in Copper Company

The purpose of this study was to evaluate the relationship between entrepreneurial strategy and resistance economy policy in Kerman Copper Company. The research is applied and descriptive. The statistical population consisted of 400 experts, supervisors and managers of Shahid Bahonar Copper Company in Kerman. Based on Morgan table, the sample size was 196 people. The standard questionnaire was used for data collection. The validity of the questionnaires was 0.93 and 0.91 respectively and the reliability of the questionnaires was higher than 0.7. Data were analyzed using SPSS software and structural equation modeling test by Amos software. The findings showed that there is a positive and significant relationship between entrepreneurial strategy and resistance economy policy in Kerman Copper Company. On this basis, it can be said that the promotion of entrepreneurial strategies will facilitate the implementation of the Resilience Policy

An In-Silico Study on the Most Effective Growth Factors in Retinal Regeneration Utilizing Tissue Engineering Concepts

Purpose: Considering the significance of retinal disorders and the growing need to employ tissue engineering in this field, in-silico studies can be used to establish a cost-effective method. This in-silico study was performed to find the most effective growth factors contributing to retinal tissue engineering. Methods: In this study, a regeneration gene database was used. All 21 protein-coding genes participating in retinal regeneration were considered as a protein–protein interaction (PPI) network via the “STRING App” in “Cytoscape 3.7.2” software. The resultant graph possessed 21 nodes as well as 37 edges. Gene ontology (GO) analysis, as well as the centrality analysis, revealed the most effective proteins in retinal regeneration. Results: According to the biological processes and the role of each protein in different pathways, selecting the correct one is possible through the information that the network provides. Eye development, detection of the visible light, visual perception, photoreceptor cell differentiation, camera-type eye development, eye morphogenesis, and angiogenesis are the major biological processes in retinal regeneration. Based on the GO analysis, SHH, STAT3, FGFR1, OPN4, ITGAV, RAX, and RPE65 are effective in retinal regeneration via the biological processes. In addition, based on the centrality analysis, four proteins have the greatest influence on retinal regeneration: SHH, IGF1, STAT3, and ASCL1. Conclusion: With the intention of applying the most impressive growth factors in retinal engineering, it seems logical to pay attention to SHH, STAT3, and RPE65. Utilizing these proteins can lead to fabricate high efficiency engineered retina via all aforementioned biological processes

Smoking Knowledge, Attitude and Behavior of Child Labor Who Live in Tehran during 2013-2014

Background: Children and adolescent smoking is one of the most important health problems in the world. There is a major concern that child labor may generate a pseudo maturity syndrome, including smoking.The current survey focus on smoking behavior, knowledge and attitude of child labor are working in Tehran.Materials and Methods: The study adopted a cross-sectional design, based on a primary pilot descriptive cross sectional study, using GYTS self-administered questionnaire. 816 child labor, which were student of work labor schools or worked as child labor on Tehran parks and crossing roads, were randomly selected using multi stage cluster sampling. DATA analyzed using SPSS v.22 (IBM statistic) software and chi square test to compare the frequency of variables in different groups.Results: 50.6% of our participants were boy and child laboring age varied from 11 to 17 years old. 18.6% of child labor had smoking experience (Confident Interval 95%=17.3-20.1). 9.8% of them were current smoker (CI 95%=8.6-10.9) and 1.2% were current regular smoker (CI 95%=0.9-2.1). Child labor smoking hazard knowledge was evaluated by considering the minimum and maximum score of 10 to 30. Results demonstrated that the mean score of knowledge, attitude and behavior were 17.1±6.2, 36.5±16.1 (range 15-45) and 46.1±3.0 (range 25-75), respectively.Conclusion: Considering to our findings, planning tobacco control program for these specific groups is required, aiming at preventing cigarette smoking by increasing the knowledge and correcting their attitude

Comparison of the effects of Crataegus oxyacantha extract, aerobic exercise and their combination on the serum levels of ICAM-1 and E-Selectin in patients with stable angina pectoris

Background: Adhesion molecules play an important role in the development and progression of coronary atherosclerosis. The aim of this study was comparing the effect of Cratagol herbal tablet, aerobic exercise and their combination on the serum levels of Intercellular adhesion molecule (ICAM)-1 and E-Selectin in patients with stable angina pectoris. Methods: Eighty stable angina pectoris patients aged between 45 and 65 years, were randomly divided into four groups including three experimental groups and one control group: aerobic exercise (E), Crataegus oxyacantha extract (S), aerobic exercise and Crataegus oxyacantha extract (S+E), and control (C). Blood sampling was taken 24 h before and after 12 weeks of aerobic exercise and Crataegus oxyacantha extract consumption. The results of serum levels of ICAM-1 and E-selectin were compared. Results: Intergroup comparison of the data revealed a significant reduction (P < 0.01) in serum levels of ICAM-1 and E-selectin in experimental groups. Analysis of data showed that the serum levels of ICAM-1 had significant difference when group S+E was compared with groups S and C, but not group E (P = 0.021, P = 0.000 and P = 0.068, respectively). Also the difference between the levels of E-selectin was significant comparing S+E and S but not E with group C (P = 0.021, P = 0.000 and P = 0.052, respectively). Conclusions: Twelve weeks effects of aerobic exercise and Crataegus oxyacantha extract consuming is an effective complementary strategy to significantly lower the risk of atherosclerosis and heart problems

Examination of causes behind procrastination among Shahrekord University of Medical Sciences employees and proposing some strategies for their preventing: A study using the Van Wyk’s Model

Background: Competition among the organizations and enterprises plays a particularly important role in the gathering of the profits and acquisition of internal and external resources. Procrastination is one of the main barriers to efforts made towards increasing the productivity and efficiency in the organizations. Accordingly, the main goal of this research was to explore the reasons of procrastination among the employees based on Van Wyk’s model and present some strategies for preventing it. Methods: Descriptive-analytical in nature, this study was conducted on a sample of 200 employees selected from Shahrekord University of Medical Sciences using a self-designed checklist developed based on the informational components incorporated in the Van Wyk’s model. This model consists of 9 factors affecting the level of procrastination observed among the employees i.e. resistance, boredom, perfectionism, last-minute syndrome, lack of motivation for a task, fear of failure, skill deficit, rebelliousness and disorganization. The validity of the developed checklist was checked using its assessment by the expert professors and its reliability was measured with Cronbach's alpha. Both of them were confirmed (Cronbach's alpha of 90%). To analyze the data, T-test and variance analysis were used.Results: The results of the study showed that there was a statistically significant relationship between employee’s resistance, boredom, perfectionism and lack of motivation for task and procrastination (p=0.001); however, the association between fear of failure, rebelliousness and disorganization and procrastination was not statistically significant (p=0.871).Conclusions: The availability of high quality organizational capital will enhance the chance of organization’s success, survival and advancement. As a result, identifying the attributes of human resources and the factors influencing their efficiency so as to exploit the human capital more optimally and remove the reasons of procrastination is of high significance.