62 research outputs found
On the variation of b-value for Karachi region, Pakistan through Gumbel’s extreme distribution method
Shaping surface acoustic waves for cardiac tissue engineering
The heart is a non-regenerating organ that gradually suffers a loss of cardiac cells and functionality. Given the scarcity of organ donors and complications in existing medical implantation solutions, it is desired to engineer a three-dimensional architecture to successfully control the cardiac cells in vitro and yield true myocardial structures similar to native heart. This thesis investigates the synthesis of a biocompatible gelatin methacrylate hydrogel to promote growth of cardiac cells using biotechnology methodology: surface acoustic waves, to create cell sheets.
Firstly, the synthesis of a photo-crosslinkable gelatin methacrylate (GelMA) hydrogel was investigated with different degree of methacrylation concentration. The porous matrix of the hydrogel should be biocompatible, allow cell-cell interaction and promote cell adhesion for growth through the porous network of matrix. The rheological properties, such as polymer concentration, ultraviolet exposure time, viscosity, elasticity and swelling characteristics of the hydrogel were investigated. In tissue engineering hydrogels have been used for embedding cells to mimic native microenvironments while controlling the mechanical properties. Gelatin methacrylate hydrogels have the advantage of allowing such control of mechanical properties in addition to easy compatibility with Lab-on-a-chip methodologies.
Secondly in this thesis, standing surface acoustic waves were used to control the degree of movement of cells in the hydrogel and produce three-dimensional engineered scaffolds to investigate in-vitro studies of cardiac muscle electrophysiology and cardiac tissue engineering therapies for myocardial infarction. The acoustic waves were characterized on a piezoelectric substrate, lithium niobate that was micro-fabricated with slanted-finger interdigitated transducers for to generate waves at multiple wavelengths. This characterization successfully created three-dimensional micro-patterning of cells in the constructs through means of one- and two-dimensional non-invasive forces. The micro-patterning was controlled by tuning different input frequencies that allowed manipulation of the cells spatially without any pre- treatment of cells, hydrogel or substrate. This resulted in a synchronous heartbeat being produced in the hydrogel construct.
To complement these mechanical forces, work in dielectrophoresis was conducted centred on a method to pattern micro-particles. Although manipulation of particles were shown, difficulties were encountered concerning the close proximity of particles and hydrogel to the microfabricated electrode arrays, dependence on conductivity of hydrogel and difficult manoeuvrability of scaffold from the surface of electrodes precluded measurements on cardiac cells. In addition, COMSOL Multiphysics software was used to investigate the mechanical and electrical forces theoretically acting on the cells.
Thirdly, in this thesis the cardiac electrophysiology was investigated using immunostaining techniques to visualize the growth of sarcomeres and gap junctions that promote cell-cell interaction and excitation-contraction of heart muscles. The physiological response of beating of co-cultured cardiomyocytes and cardiac fibroblasts was observed in a synchronous and simultaneous manner closely mimicking the native cardiac impulses. Further investigations were carried out by mechanically stimulating the cells in the three-dimensional hydrogel using standing surface acoustic waves and comparing with traditional two-dimensional flat surface coated with fibronectin. The electrophysiological responses of the cells under the effect of the mechanical stimulations yielded a higher magnitude of contractility, action potential and calcium transient
Synthons for supramolecular assemblies: Synthesis of new triazine-core polyhydroxylated and multi-N-donor compounds
The synthesis of new triazine-core polyhydroxylated and multi-N-donor compounds are being reported. The reaction of 2,4,6-tris(4-n-butylaminophenyl)triazine (1) with cyanuric chloride provided star-shaped fragment (2) with six reactive chloro-substituents. Upon treatment of this fragment with bis(2-hydroxyethyl)amine (3a) and bis(2-pyridylmethyl)amine (3b), functionalized polyhydroxylated (4a) and multi-N-donor compounds (4b) were obtained in high yields through nucleophilic aromatic substitution. These functionalized compounds are expected to have unique applications in supramolecular self-assembly and material chemistry
Utilization of RSM for optimization of physical variables to improve bacteriocin production from Lactobacillus plantarum strain MS
The utilization of natural antimicrobial substances has been increased in the pharmaceutical sector due to their stability and inhibition activity against pathogenic microorganisms. In the current study, the bacteriocin synthesis by locally isolated Lactobacillus plantarum MS from yogurt, has been optimized by using response surface methodology. Statistical optimization of physical variables by using Box-Behnken design, 3200 AU/mL bacteriocin activity was detected at 30 °C temperature, 18h incubation time and pH 6 against Staphylococcus aureus. The resulting bacteriocin was found to be stable a broad range of pH (2-12) and temperature (37-100 °C) but the activity of bacteriocin was slightly disturbed at 121 °C. Besides, bacteriocin showed stability after treatment with various enzymes (catalase, amylase, and lipase), salt (NaCl), and surfactants (triton X-100, EDTA, and SDS) but found sensitive by treating with proteolytic enzymes (proteinase K and trypsin) in comparison with untreated bacteriocin. Because of such biochemical characteristics, these antibacterial peptides could be possibly incorporated in the field of pharmacy to fulfil consumer’s demand for natural remedies
A systemic review of existing serological possibilities to diagnose canine osteoarthritis with a particular focus on extracellular matrix proteoglycans and protein
Extra-cellular matrix (ECM) components are important and their stabilization
is significant in maintaining normal healthy joint environment. In
osteoarthritis (OA), ECM components are altered and indicate disease
progression. The joint ECM is composed of proteoglycans (aggrecan, perlecan,
inter a-trypsin inhibitor), glycoproteins (fibronectin, lubricin, COMP) and
collagen types (most abundantly collagen type II) which represent structural
and functional transformation during disease advancement. ECM investigation
revealed significant biomarkers of OA that could be used as a diagnostic and
therapeutic tool in different canine orthopedic diseases. This review
deliberates our current findings of how the components of ECM change at the
molecular level during disease progression in canine OA
Short term outcome of primary un-cemented total hip arthroplasty in osteonecrosis of femoral head
Background: Osteonecrosis of femoral head (ONFH) is characterised by cell death in the subchondral bone caused by abnormalities of blood flow to the femoral head. About 5% to 13% of arthroplasties are performed yearly for ONFH in United States. Ficat and Arlet classification is the commonest system used for grading of ONFH. Advanced stages 3 and 4 are best managed with total hip arthroplasty (THA). THA restores hip range of movement and allows early ambulation in ONFH.Methods: After seeking approval from local institutional ethical committee 25 patients with stage 3 and stage 4 ONFH (Ficat and Arlet) were admitted from OPD of SKIMS MC and Hospital Bemina, Srinagar. The study was conducted from February 2018 to February 2020 in department of Orthopaedics SKIMS MC and Hospital Bemina, Srinagar. 25 patients with mean age of 50.64 years comprising of 13 females and 12 males with unilateral osteonecrosis of femoral head with collapsed head underwent uncemented total hip arthroplasty and were followed up to a minimum of 1 year post-operatively.Results: Outcome was evaluated by comparing pre-operative and post-operative Harris hip scores. The average Harris hip scores improved from 65.87 in the pre-operative group to 96.54 at 1-year follow-up post-operatively. Marked improvement was noted in pain scores. No revisions were performed during the study. One patient developed superficial surgical site infection which healed with supervised dressings and oral antibiotics.Conclusions: Uncemented THA has excellent short-term outcomes in advanced stages of ONFH. It provides mobile hip joint and pain free ambulation shortly after surgery
Surface acoustic waves induced micropatterning of cells in gelatin methacryloyl (GelMA) hydrogels
Acoustic force patterning is an emerging technology that provides a platform to control the spatial location of cells in a rapid, accurate, yet contactless manner. However, very few studies have been reported on the usage of acoustic force patterning for the rapid arrangement of biological objects, such as cells, in a three-dimensional (3D) environment. In this study, we report on a bio-acoustic force patterning technique, which uses surface acoustic waves (SAWs) for the rapid arrangement of cells within an extracellular matrix-based hydrogel such as gelatin methacryloyl (GelMA). A proof-of-principle was achieved through both simulations and experiments based on the in-house fabricated piezoelectric SAW transducers, which enabled us to explore the effects of various parameters on the performance of the built construct. The SAWs were applied in a fashion that generated standing SAWs (SSAWs) on the substrate, the energy of which subsequently was transferred into the gel, creating a rapid, and contactless alignment of the cells (<10 s, based on the experimental conditions). Following ultraviolet radiation induced photo-crosslinking of the cell encapsulated GelMA pre-polymer solution, the patterned cardiac cells readily spread after alignment in the GelMA hydrogel and demonstrated beating activity in 5–7 days. The described acoustic force assembly method can be utilized not only to control the spatial distribution of the cells inside a 3D construct, but can also preserve the viability and functionality of the patterned cells (e.g. beating rates of cardiac cells). This platform can be potentially employed in a diverse range of applications, whether it is for tissue engineering, in vitro cell studies, or creating 3D biomimetic tissue structures
Serum malondialdehyde and adiponectin in albuminuric kidney disease patients
Background: Diabetes, hypertension, oxidative stress, obesity, adipocytokine dysfunction, and dyslipidemia are causative factors in development of Chronic Kidney Disease (CKD). Adiponectin secreted from adipose tissue, has Reno protective effect against development of albuminuria in animal studies. The previous studies investigated the relationship between serum adiponectin level and urinary albuminuria in kidney disease patients, but the results are conflicting.Methods: The pre diagnosed kidney disease patients were divided into microalbuminuria and macroalbuminuria groups, while control subjects were called as normoal buminuria group. The pre diagnosed adult kidney disease patients of both genders with age matching control subjects with no known comorbidity were included in the study. Whereas pregnant female patients and the patients with comorbidity were excluded from the study. The demographic data and the anthropometric data of control and kidney patients were recorded. The blood was analyzed for Glycosylated Hemoglobin (HbA1c), electrolytes, glucose, calcium, total protein, albumin, urea, creatinine adiponectin and malondialdehyde. The Urine was analyzed for Creatinine and albuminuria. The glomerular filtration rate was estimated.Results: The blood pressure, blood urea, creatinine, glycated hemoglobin, malondialdehyde, adiponectin levels were higher in albuminuric kidney patients as compared to normal control subjects. The mean glomerular filtration rate was lowest in macroalbuminuric patients as compared to micro and normoalbuminuric patients. The serum adiponectin and serum malondialdehyde both showed positive correlation with serum creatinine, and with albuminuria/urinary creatinine ratio.Conclusions: The study concludes that, positive correlation of serum malondialdehyde with adiponectin and albuminuria
Development and Evaluation of Hand Operated Apple Peeler
777-779The aim of the present study was to develop and evaluate a low cost, small scale hand operated apple peeler. A low-cost durable hand operated apple peeler having overall dimensions of 305 mm × 225 mm × 30 mm was fabricated. The performance of the developed prototype was evaluated for different parameters in comparison to manual peeling (using knives). Significantly (p<0.05) high peeling capacity (42 kg/hour), high percentage of peel removal (17.92) and high depth of cut (0.95 mm) were recorded for developed hand operated apple peeler in comparison to manual peeling (i.e., knives). In contrast, significantly (p<0.05) lower peeling efficiency of 84% and labor requirement of 23.80 man hr/ton were recorded in case of hand operated apple peeler whereas in case of manual peeling it was recorded as 100% and 51.28 man hr/ton respectively
Ecological Applications of Enzymes in Plants Based Textile Dyeing
Biotechnology has a foremost role in the textile industry by enhancing ecofriendly, cost-effective, and energy-efficient manufacturing processes. The use of enzymatic biotechnology is one of the sustainable newly developed state-of-the-art processes for textile processing. To reduce the use of toxic and hazardous chemicals, enzymes have been proposed as one of the finest promising alternatives. Many enzymes have been used widely in textile processes such as lipase, laccase, pectinase, cellulase, catalase, amylase, and protease. The enzymatic use in the textile industry is very promising because they produce top-class goods, and give way to the reduction of water, time, and energy. The increasing demand for natural dyes especially with the incorporation of enzymes makes process more sustainable and eco-friendlier to suppress the toxicity of synthetic dyes. In the first part of the chapter, particular attention has been given to the source and extraction of natural dyes. In the second part of the chapter, different enzymes and their possible roles in the textile industry have been discussed. It is expected that this chapter will provide an innovative direction to the academic researchers, the community of textile and traders as well as artisans who are working in the area of biotechnological applications for the betterment of textile processing
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