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Characterization, drug loading and antibacterial activity of nanohydroxyapatite/polycaprolactone (nHA/PCL) electrospun membrane
No full textConsidering the important factor of bioactive nanohydoxyapatite (nHA) to enhance osteoconductivity or bone-bonding capacity, nHA was incorporated into an electrospun polycaprolactone (PCL) membrane using electrospinning techniques. The viscosity of the PCL and nHA/PCL with different concentrations of nHA was measured and the morphology of the electrospun membranes was compared using a field emission scanning electron microscopy. The water contact angle of the nanofiber determined the wettability of the membranes of different concentrations. The surface roughness of the electrospun nanofibers fabricated from pure PCL and nHA/PCL was determined and compared using atomic force microscopy. Attenuated total reflectance Fourier transform infrared spectroscopy was used to study the chemical bonding of the composite electrospun nanofibers. Beadless nanofibers were achieved after the incorporation of nHA with a diameter of 200–700 nm. Results showed that the fiber diameter and the surface roughness of electrospun nanofibers were significantly increased after the incorporation of nHA. In contrast, the water contact angle (132° ± 3.5°) was reduced for PCL membrane after addition of 10% (w/w) nHA (112° ± 3.0°). Ultimate tensile strengths of PCL membrane and 10% (w/w) nHA/PCL membrane were 25.02 ± 2.3 and 18.5 ± 4.4 MPa. A model drug tetracycline hydrochloride was successfully loaded in the membrane and the membrane demonstrated good antibacterial effects against the growth of bacteria by showing inhibition zone for E. coli (2.53 ± 0.06 cm) and B. cereus (2.87 ± 0.06 cm)
Continuous presence of male on estrus onset, estrus duration, and ovulation in estrus-synchronized Boer goats
No full textThe objectives of the present study were to assess the effect of permanent contact of teasers without copulation on the interval from controlled internal drug release (CIDR) removal to estrus onset, estrus duration, ovulation time, number of ovulations, and interval from CIDR removal to ovulation time on estrus-synchronized Boer goats. During the fall season, a controlled randomized design experiment with two groups, control (CON; n = 18) and treatment (TRE; n = 18), was performed. The TRE group was maintained permanently in a pen with an aproned buck immediately after CIDR removal. The CON group was maintained in a different pen without permanent exposure to the male. All females were estrus synchronized with CIDR maintained in the vagina for 7 days and received 50 μg of GnRH im at device insertion and 5 mg of natural prostaglandin F-2α at device removal. Females were considered to be in estrus when they accepted mounting by the aproned bucks. Estrus was detected four times a day after CIDR removal (at 6 AM, 12 noon, 6 PM, and 12 midnight) using bucks with canvas apron as teasers. The ovulation time and number of ovulations were assessed by transrectal ultrasonography starting 24 hours after estrus onset and repeated every 6 hours until complete ovulation was detected. The estrus onset for the CON group was 44.0 ± 8.3 hours and for the TRE group, it was 37.0 ± 7.7 hours (P = 0.01). Estrus duration from the CON group was 43.7 ± 9.2 hours and for the TRE group, it was 38.3 ± 6.6 hours (P = 0.05). The first, last, and mean ovulation times for the CON group were 32.4 ± 5.3, 38.4 ± 3.4, and 35.4 ± 3.9 hours, and for the TRE group, the times were 31.8 ± 2.8, 36.7 ± 3.0, and 35.8 ± 3.6 hours, respectively (P = 0.85, P = 0.23, and P = 0.82, respectively). The number of ovulations for the CON and TRE groups was 2.6 ± 0.7 and 2.6 ± 0.6 ovulations, respectively (P = 0.96). The interval time for CIDR removal to ovulation for the CON group was 79.2 ± 8.2 hours and for the TRE group, the interval time was 73.2 ± 6.2 hours (P = 0.05). It was concluded that the permanent presence of male without copulation with estrus-synchronized does hastened estrus onset, reduced estrus duration, and decreased the interval time from CIDR removal to ovulation without modification of ovulation time and number of ovulations in Boer goats
Survival Analysis of the Men’s 100 Meter Dash Record
Get PDFIn the 2012 Summer Olympics in London seven out of eight finalists in the men’s 100 meter dash crossed the finish line in under 10 seconds. This result and other recent performances of exceptional sprinters such as Bolt have made experts wonder, not whether a new record will be set, but when and how much it will lower the present record. Seeking an answer, some researchers have tried to model the available data with the goal of using them to predict future records. This article presents a different approach based on theory of records for independent and identically distributed observations. It modifies the number of attempts to break a record to make the results of the theory of records applicable to this situation. The modification is necessary because many sports records have been broken more frequently than what this theory predicts. Two modifications of the number of attempts are considered, fixed rate via a geometric increase, and random rate via a non-homogeneous Poisson process
On Factorization of a Special type of Vandermonde Rhotrix
Get PDFVandermonde matrices have important role in many branches of applied mathematics such as combinatorics, coding theory and cryptography. Some authors discuss Vandermonde rhotrices in the literature for its mathematical enrichment. Here, we introduce a special type of Vandermonde rhotrix and obtain its LR factorization, namely left and right triangular factorization which is further used to obtain the inverse of the rhotrix
Random variational-like inclusion and random proximal operator equation for random fuzzy mappings in Banach spaces
Get PDFIn this paper, we introduce and study a random variational-like inclusion and its corresponding random proximal operator equation for random fuzzy mappings. It is established that the random variational-like inclusion problem for random fuzzy mappings is equivalent to a random fixed point problem. We also establish a relationship between random variational-like inclusion and random proximal operator equation for random fuzzy mappings. This equivalence is used to define an iterative algorithm for solving random proximal operator equation for random fuzzy mappings. Through an example, we show that the random Wardrop equilibrium problem is a special case of the random variational-like inclusion problem for random fuzzy mappings
A Numerical Scheme for Generalized Fractional Optimal Control Problems
Get PDFThis paper introduces a generalization of the Fractional Optimal Control Problem (GFOCP). Proposed generalizations differ in terms of explaining the constraint involved in the dynamical system of the control problem. We assume the constraint as an arbitrary function of fractional derivatives and fractional integrals. By this assumption the restriction on constraint, to be of some prescribed function of fractional operators, is removed. Deduction of necessary optimality conditions followed by particular cases and examples has been provided. Additionally, we construct a solution scheme for the suggested class of (GFOCP)’s. The formulation of this scheme is done by implementing the Adomian decomposition method on necessary optimality conditions. An example is presented to demonstrate the application of solution scheme. Fractional operators used throughout the paper are either Riemann-Liouville or Caputo’s fractional operators
Spectral Numerical Calculation of Non-isothermal Flow through a Rotating Curved Rectangular Duct with Moderate Curvature
Get PDFThe present paper investigates non-isothermal flow characteristics through a rotating curved rectangular duct, where co-existence of the rotational forces and fluid temperature gradients leads to the emergence of rotation-induced buoyancy effects. A spectral-based numerical scheme is employed as the principal tool for the simulation while Chebyshev polynomial and collocation method as the secondary tools. The outer wall of the duct is heated while the inner wall cooled, the top and bottom walls being thermally insulated. The emerging parameters controlling the flow characteristics are the rotation parameter, i.e., the Taylor number Tr ranging 0 to 2000, the Grashof number Gr = 100, the Prandtl number Pr, the aspect ratio, and the pressure-driven parameter, i.e., the Dean number Dn between 100 and 1000. The flow structures are examined under combined action of the centrifugal, Coriolis and buoyancy forces. As a result, asymmetric 2-cell structures are computed for small values of Tr while asymmetric 6-cell structures for large Tr. Unsteady flow characteristics show that the flow undergoes in the scenario ‘chaotic→ multi-periodic → periodic→ steady-state’, if Tr is increased in the positive direction. Typical contours of secondary flow patterns, temperature profiles and axial flow distribution are also obtained at several values of Tr, and it is found that there exist asymmetric two- to multi-vortex solutions. Heating the outer wall is found to generate a significant temperature gradient at the outer concave wall
Robust H∞switching control of polytopic parameter-varying systems via dynamic output feedback
No full textThe problem of designing a globally optimal robust output-feedback controller for time-varying polytopic uncertain systems is a well-known non-convex optimization problem. In this paper, new sufficient conditions for robust H∞outputfeedback control synthesis are proposed in terms of a special type of bilinear matrix inequalities (BMIs), which can be solved effectively using linear matrix inequality (LMI) optimization plus a line search. In order to reduce the conservatism of robust output-feedback control methods based on single quadratic Lyapunov function, we utilize multiple Lyapunov functions. The associated robust output-feedback controller is constructed as a switching-type full-order dynamic output-feedback controller, consisting of a family of linear subcontrollers and a min-switching logic. The proposed approach features the important property of computational efficiency with stringent performance. Its effectiveness and advantages have been demonstrated through numerical studies
Fabrication and characterization of pcl/ha/ppy composite scaffold using freeze-drying technique
No full textBone tissue regeneration and healing could be notably quickened via applying electrical stimuli in the defected area. Hence, a conductive tissue engineering scaffold that is capable of delivering the electrical stimuli is greatly desirable. In this study, electrically conductive scaffold was fabricated by using a biocompatible conductive polymer, polypyrrole (PPY) in the optimized nanocomposite scaffold of Polycaprolactone (PCL) and Hydroxyapatite (HA) using freeze-drying technique. The scaffolds were evaluated by using a number of techniques. The morphology of the scaffolds was observed and analyzed using a scanning electron microscope (SEM). Composite scaffolds with suitable pore size distribution were obtained by freezing the polymer solution mixture at-18ºC, by controlling the polymer and solvent phase crystallization. The results showed that the average pore sizes were decreased from 123.7μm for PCL scaffolds to 91.6μm with the incorporation of HA nanoparticles. Electrical conductivity of the scaffolds was evaluated using a digital multimeter. The wettability and porosity of the scaffolds were increased with the incorporation of Polypyrrole than Polycaprolactone scaffold. The newly fabricated PCL/HA/PPY scaffold showed good prospect to be employed for bone tissue engineering applications
