Glycosaminoglycan Stabilization Reduces Tissue Buckling in Bioprosthetic Heart Valves

Currently, bioprosthetic heart valves are crosslinked with glutaraldehyde to prevent tissue degradation and to reduce tissue antigenicity. Glutaraldehyde forms stable crosslinks with collagen via a Schiff base reaction of the aldehyde with an amine group of the hydroxylysine/lysine in collagen. However, within a decade of implantation, 20-30% of these bioprostheses will become dysfunctional and over 50% will fail due to degeneration within 12-15 years post-operatively. Gylcosaminoglycans, a major constituent of valvular tissue, play an important role in maintaining a hydrated environment necessary for absorbing compressive loads, modulating shear stresses, and resisting tissue buckling. One of the disadvantages of glutaraldehyde crosslinking is its incomplete stabilization of GAGs, which lack the amine functionalities necessary for fixation by aldehyde addition. Previous studies have reported a greater depth of buckling in glutaraldehyde crosslinked aortic valves, one of the major causes of failure in these bioprostheses. Buckling occurs at sites of sharp bending, producing large stresses that can eventually lead to mechanical fatigue and consequent valvular degeneration. Local structural collapse occurs at these areas of tissue buckling to minimize compressive stresses, which subsequently causes a reduction in tissue length. Previous studies have reported the loss of GAGs in glutaraldehyde crosslinked porcine cusps during fixation, storage, in vitro fatigue experimentation, and in vivo subdermal implantation due to enzyme-mediated GAG degradation. Additionally, GAG loss has been observed in failed porcine bioprosthetic heart valves following clinical use. Therefore, to evaluate the potential role of GAGs in reduction of buckling in bioprosthetic heart valves, we used two 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) based crosslinking chemistries that link GAG carboxyl groups to the amine groups of proteins. Neomycin trisulfate, a hyaluronidase inhibitor, was employed to effectively stabilize the GAGs and subsequently prevent its enzymatic degradation. Previously, stabilization of valvular GAGs using neomycin trisulfate, a GAG-enzyme inhibitor, coupled with carbodiimide fixation chemistry was found to resist in vitro and in vivo enzymatic degradation of GAGs. Thus, using the above-mentioned GAG-targeted fixation strategies, we demonstrate that the retention of valvular GAGs reduces the extent of buckling in bioprosthetic heart valves, which may subsequently improve the durability of these bioprostheses

Analyzing and Benchmarking of 5 Potential Software of New ERP for better Inventory Management System for case company

This Thesis is commissioned by Stafix Oy Finland. The case company was interested in finding out new ERP tool for their inventory management. The research questions were formulated as follow: How can the company receive inventory recording and calculation automatically with traceability of produced goods as well? And what are the major pros and cons of the suggest 5 potential software solution (easy to use and affordability)? Addition to providing solution to the above question, the cost comparison of those suggested ERP tools was also important. The thesis presents the theoretical background related to the software and its quality and functionality, ERP tools, benchmarking of suggested tools, Inventory management etc. The methodology applied is qualitative approach in which primary data were collected through semi-structured interviews and questionnaire. The two interviews were carried out with the managers of different companies which are using the ERP software in their companies and the software which are being analyzed by the researcher in this thesis are used by these companies. The secondary data were collected through different journals, publications, books related to the topic and basis of the topic to provide the overview of the related subject under which the thesis is being commissioned. An interview was also held with the CEO of the case company to the current issue that are being faced by the company and the expectation related to the new potential software. The questionnaire was answered by the employees of the case company. The aim of the questionnaire was to know the current status of the software that is being used by the case company and the problems that are being faced by the employees as well as the decision makers related to the software. The researcher analyzed the interviews and questionnaire to provide the final outcome to the case company which would help the case company to choose one of the 5 suggested ERP tools for them. The researcher was able to handover the detail analysis and results related to the use, cost, efficiency etc. related to the potential software based on the theoretical research as well as empirical data collection, out of which company can choose which suits best for them

Numerical Simulation of High Velocity Impact of a Single Polymer Particle during Cold Spray Deposition

Abstract The cold spray process is an additive manufacturing technology primarily suited for ductile metals, and mainly utilized in coating surfaces, manufacturing of freeform parts and repair of damaged components. The process involves acceleration of solid micro-particles in a supersonic gas flow and coating build-up by bonding upon high velocity impact onto a substrate. Coating deposition relies on the kinetic energy of the particles. The main objective of this study was to investigate the mechanics of polymer cold spray process and deformation behavior of polymers to improve technological implementation of the process. A finite element model was created to simulate metal particle impact for copper and aluminum. These results were compared to the numerical and experimental results found in the literature to validate the model. This model was then extended to cover a wide range of impact conditions, in order to reveal the governing mechanisms of particle impact and rebound during cold spray. A systematic analysis of a single high-density polyethylene particle impacting on a semi-infinite high density polyethylene substrate was carried out for initial velocities ranging between 150m/s and 250m/s by using the finite element analysis software ABAQUS. A series of numerical simulations were performed to study the effect of a number of key parameters on the particle impact dynamics. These key parameters include: particle impact velocity, particle temperature, particle diameter, and particle density, composition of the polyethylene particle, surface composition and the thickness of a polyethylene film on a hard metal substrate. The effect of these parameter variations were quantified by tracking the particle temperature, deformation, plastic strain and rebound kinetic energy. The variation of these parameters helped define a window of deposition where the particle is mostly likely to adhere to the substrate

Spontaneous Penile (Cavernosal) Abscess: Case Report with Discussion of Aetiology, Diagnosis, and Management with Review of Literature

The rare presentation of spontaneous, corpus cavernosal abscess with evident pus discharge is reported. The 19-year-old English man was successfully treated with surgical drainage and antibiotics with long-term sequelae in form of mild, left-sided penile deviation, but normal erectile function. Though he did not require any further surgical intervention for correction of chordee at that time, there remains a possibility of it getting worse over time, which may ultimately need surgery for correction. The possible aetiology, diagnosis, and treatment of this rare condition are briefly discussed

Home Control and Monitoring

Home automation is rapidly growing at present. People need comfort and convenience. In this paper, I give an overview of the home automation through power line communication (PLC) technology. This paper presents an overview of the research, methods, applications, standards and some of the critical features of the power line communication. Powerline communication is one of the most emerging home network technology that allows consumers to use their already existing powerline wires to connect home appliances to each other and the Internet. By using power lines, it the most innovative way to home automation, reducing the congested wifi devices and external cables.B.S. (Bachelor of Science

Evaluation of in Vitro Antioxidant Activity and L Asparaginase Enzyme Production of Four Endophytic Fungi Isolated from Acanthus Ilicifolius

The need for novel and useful bioactive secondary metabolites to help and relieve people from all aspects of human conditions is constantly expanding. Every plant tissue has a variety of endophytic fungi, which are thought to be highly effective producers of natural products. In this work, the determination of total phenolics, antioxidants, and L-asparaginase enzyme activity in four fungal endophytes associated with the mangrove plant Acanthus ilicifolius was evaluated. The study indicated that total phenolic content (1633+8.7 μg equivalent to gallic acid) and reducing power (0.96) were the highest for methanolic extracts of the isolate Aspergillus terreus while scavenging activity was highest for the isolate Colletotrichum xishuangbannaense (78.2+4.5 %). The enzyme activity of L-asparaginase was expressed predominantly by all the isolates except Colletotrichum xishuangbannaense. Maximum enzyme activities of 50.1 U/mL, 48.1 U/mL, and 47.7 U/mL were observed in Aspergillus terreus, Colletotrichum cobbiƫense, and Fusarium multiceps respectively. The current research demonstrated that mangrove-associated fungi have a high potential for producing bioactive molecules and L-asparaginase, which can be used as a possible source for the creation of anticancer drugs

Potential impact of Big Data in Real World Sectors

In this information and digital era vast amount of data have become available on hand to decision makers.Big data represents not only the huge amount of data but also the data which are high in variety and velocity.Due to the galloping growth of the data, solutions are needed to handle,analyse, and extract the information from the datasets.Big data has a potential impact on the digital world.After examining the impact of big data on various fields and sectors,this paper presents a brief review of what is big data and the use of big data in our real world.In this paper, we have addressed the various type of fields where big data is used such as Digital Space,Healthcare, Finance,Education and Government