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In vitro cytotoxicity and antibacterial activity of silver-coated electrospun polycaprolactone/gelatine nanofibrous scaffolds
No full textThe development of nano-sized scaffolds with antibacterial properties that mimic the architecture of tissue is one of the challenges in tissue engineering. In this study, polycaprolactone (PCL) and PCL/gelatine (Ge) (70:30) nanofibrous scaffolds were fabricated using a less toxic and common solvent, formic acid and an electrospinning technique. Nanofibrous scaffolds were coated with silver (Ag) in different concentrations of silver nitrate (AgNO3) aqueous solution (1.25, 2.5, 5, and 10 %) by using dipping method, drying and followed by ultraviolet (UV) photoreduction. The PCL/Ge (70:30) nanofibrous scaffold had an average fibre diameter of 155.60 ± 41.13 nm. Characterization showed that Ag was physically entrapped in both the PCL and PCL/Ge (70:30) nanofibrous scaffolds. Ag+ ions release study was performed and showed much lesser release amount than the maximum toxic concentration of Ag+ ions in human cells. Both scaffolds were non-toxic to cells and demonstrated antibacterial effects towards Gram-positive Bacillus cereus (B. cereus) and Gram-negative Escherichia coli (E. coli). The Ag/PCL/Ge (70:30) nanofibrous scaffold has potential for tissue engineering as it can protect wounds from bacterial infection and promote tissue regeneration
Fabrication and characterization of chitosan coated and uncoated pcl/ha/ppy composite scaffoldsusing freeze drying technique
No full textChitosan is an abundantly common, naturally occurring, polysaccharide biopolymer. In this study, chitosan was used to coat previously fabricated conductive Polycaprolactone/Hydroxyapatite/Polypyrrole (PCL/HA/PPY) composite scaffold and the properties of the coated and non-coated scaffolds were investigated and compared. The morphology of the chitosan coated and non-coated scaffolds were characterized using a scanning electron microscope (SEM). The wettability was determined using a water contact angle measuring system. Furthermore, water uptake was determined by measuring the water absorption of each sample before and after coated with chitosan. Water contact angle result revealed an increase in wettability of the scaffolds ranging from 108° ± 4.2 down to 59.4° ± 0.7. On the other hand, the coated sample showed a higher water uptake than the non-coated sample. The results indicated that coating with chitosan was important to increase water absorption of composite scaffold, rendering it more hydrophilic
Panther - March 2016 Class The Unknown 8
Get PDFhttps://digitalcommons.pvamu.edu/pv-panther-newspapers2016/1000/thumbnail.jp
Cost of construction: How globalization impacts on vernacular houses
No full textHistorically people in vernacular area did not have to pay to become a householder or a landowner, or even to buy materials. But that is not the case in modern era any more. Besides the fact that one has to buy land or house, modern materials and technology, spread out by the flow of globalization, has also been associated with increasing cost. In this study on vernacular houses in Northern Iran, traditional (Kali, Lar deh ee, and Mud Houses) and modern (load bearing brick wall structure, concrete structure and steel structure) construction technologies have been investigated with regards to their cost. Residents, experts and contractors were interviewed to collect the data. Findings showed that the perception of cost is a skewed one, and decision to choose a new material or technical over san old one needs to be rational
REVIEW: Challenges and opportunities in rising feral horse populations
No full textThe ever-increasing feral horse population in the United States is creating both challenges and opportunities that affect science, the environment, and society. Although the presence of feral horses is well-known, the implications of these rapidly growing populations are not fully appreciated nor understood. In this review, the aims are to first summarize the nature of the feral horse populations in the United States and then to discuss the main challenges along with their impact and potential solutions. Our analysis is expected to be helpful both for the scientific community as well as the public in the United States and elsewhere
Effect of copulation on estrus duration and ovulation time in goats
No full textThe objective of the present study was to evaluate the effect of copulation on estrus duration and ovulation in goats. During the fall season, 14 multiparous Boer does were estrous synchronized with controlled internal drug release (300 mg), maintained in the vagina for 7 days, and received 50 μg of intramuscular GnRH device insertion and 5 mg of natural intramuscular PGF2α at device removal. The does were randomly divided into two equal groups: a treatment group (TRE; n = 7) and a control group (CON; n = 7). The TRE group received two copulas by fertile bucks within the first 4 hours of estrus onset, and the CON group received only mounts by the same males equipped with canvas aprons. Estrus detection was performed every 12 hours after controlled internal drug release removal within the first 24 hours and then every 4 hours for 5 days. Estrus was defined when a doe accepted mounting by the bucks equipped with canvas aprons. Each doe in estrus got the first transrectal ultrasonography at 24 hours after estrus onset and then every 4 hours until all the preovulatory follicles ovulated. Estrus onset for the TRE and CON groups was 40.3 ± 17.4 (mean ± standard deviation) and 43.3 ± 12.2 hours (P = 0.72), respectively. Estrus duration for the same groups was 28.6 ± 5.4 and 36.7 ± 5.3 hours (P = 0.02), respectively. The mean ovulation time for the TRE and CON groups was 31.4 ± 2.2 and 35.7 ± 3.7 hours (P = 0.04), respectively. The proportion of ovulations that occurred after the end of estrus in the TRE group was higher than in the CON group (86% vs. 33%, respectively; P = 0.05). The number of ovulations for the TRE group was 2.1 ± 0.7; for the CON group, there were 2.2 ± 0.5 ovulations (P = 0.92). It was concluded that copulation by a buck at the beginning of estrus reduced estrus duration and hastened the ovulation time in Boer goats
Dispersion Characteristics of non-Newtonian fluid during transportation of nanoparticles in permeable capillary
Get PDFThe present analysis deals with the dispersion characteristics of blood described as Herschel- Bulkley fluid in capillary with permeable walls for fluid and impermeable for the nanoparticles. The contribution of molecular and convective diffusion is recalled from the Taylor and Aris coefficient of diffusion. The effective longitudinal diffusion depends on three parameters namely rheological parameter, pressure parameter, and the permeability parameter. We investigate the influence of the longitudinal transport of nanoparticles with permeable blood vessels on the effective dispersion. It shows that the effective diffusion of nanoparticles reduces with increase in radius of the plug region (i.e., the volume of red blood cells) and the permeability of the blood vessels
ON EXTENSION OF MITTAG-LEFFLER FUNCTION
Get PDFIn this paper, we study the extended Mittag -Leffler function by using generalized beta function and obtain various differential properties, integral representations. Further, we discuss Mellin transform of these functions in terms of generalized Wright hyper geometric function and evaluate Laplace transform, and Whittaker transform in terms of extended beta function. Finally, several interesting special cases of extended Mittag -Leffler functions have also be given
Upper, Lower Solutions and Analytic Semigroups For a Model with Diffusion
Get PDFIn this discussion we consider an autonomous parabolic epidemic 2-dimensional system modelling the dynamics of transmission of immunizing diseases for a closed population into bounded regular domain. Our model takes into account diffusion of population with external influx as well as one class of infected individuals. We study the well-posedness two-component diffusion equations including external supplies with Neumann conditions using upper/lower solutions and analytic semigroups. In case of constant population or not, with non-oscillatory solution and constant diffusion, this problem admits travelling wave solutions whose minimum wave speed is surveyed here
Cobb-Douglas Based Firm Production Model under Fuzzy Environment and its Solution using Geometric Programming
Get PDFIn this paper, we consider Cobb-Douglas production function based model in a firm under fuzzy environment, and its solution technique by making use of geometric programming. A firm may use many finite inputs such as labour, capital, coal, iron etc. to produce one single output. It is well known that the primary intention of using production function is to determine maximum output for any given combination of inputs. Also, the firm may gain competitive advantages if it can buy and sell in any quantities at exogenously given prices, independent of initial production decisions. On the other hand, in reality, constraints and/or objective functions in an optimization model may not be crisp quantities. These are usually imprecise in nature and are better represented by using fuzzy sets. Again, geometric programming has many advantages over other optimization techniques. In this paper, Cobb-Douglas production function based models are solved by applying geometric programming technique under fuzzy environment. Illustrative numerical examples further demonstrates the feasibility and efficiency of proposed model under fuzzy environment. Conclusions are drawn at last