Evaluation of Wound Healing Activity of Angiotensin Converting Enzyme Inhibitors in Wistar Rats

Angiotensin converting enzyme (ACE) inhibitors are known to increase the level of bradykinin by preventing its breakdown and also promote prostaglandin synthesis by direct and indirect methods which in turn may promote wound healing. However there is paucity of scientific information in this regard. Therefore in the present study we have investigated the effect of ACE inhibitors like Captopril and Enalapril on different wound models in Wistar rats. Excision, resutured incision and dead space wounds were inflicted in male Wistar rats under light ether anaesthesia, taking aseptic precautions. Control animals received vehicle and other groups received Captopril (10mg/kg) and Enalapril (10mg/kg) orally for a period of 10 days in incision and dead space wound models, whereas similar treatments were continued in excision wound models till complete closure of wounds. On the 11th day, after estimating breaking strength of resutured incision wounds (under anaesthesia), granulation tissue was removed from dead space wounds to estimate breaking strength, hydroxyproline content as well as quantification of granulation tissue and histological studies were carried out in control and treated groups. Captopril and Enalapril significantly increased the rate of wound healing, reduced the number of days required for complete epithelialization and final area of scar in excision wounds. Both the ACE inhibitors significantly increased breaking strength of resutured incision wounds and granulation tissue. Also these two drugs significantly enhanced both granulation tissue formation and granulation tissue hydroxyproline content. Histological studies confirmed these findings. Captopril and Enalapril significantly promoted the healing process in all the three wound models studied. These results indicate the wound healing property of ACE inhibitors and clinical studies in this regard are worthwhile

Pool boiling of deionised water over polyurethane coated surfaces

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.Preliminary investigations are done to cater the possibility of the use of the polyurethane coating for the pool boiling heat transfer augmentation. Experiments have been done on the bare stainless steel heater and stainless steel heaters coated with polyurethane coatings of different thicknesses, by boiling deionised water at constant atmospheric pressure. Contact angle formed by the deionised water over the test specimen are experimentally measured and from these values the solidliquid surface energy values have been calculated. It has been found that the polyurethane coating has increased the solidliquid surface energy and the heat transfer. Recommendations for the future inspections with relevance to finding an ideal heat transfer enhancer coating are putforth

D0 Matrix Mechanics: New Fuzzy Solutions at Large N

We wish to consider in this report the large N limit of a particular matrix model introduced by Myers describing D-brane physics in the presence of an RR flux background. At finite N, fuzzy spheres appear naturally as non-trivial solutions to this matrix model and have been extensively studied. In this report, we wish to demonstrate several new classes of solutions which appear in the large N limit, corresponding to the fuzzy cylinder,the fuzzy plane and a warped fuzzy plane. The latter two solutions arise from a possible "central extension" to our model that arises after we account for non-trivial issues involved in the large N limit. As is the case for finite N, these new solutions are to be interpreted as constituent D0-branes forming D2 bound states describing new fuzzy geometries.Comment: revised version: references added, derivation of "central extensions" improved upon. To appear in JHE

Heater surface coating effect on fluidized bed heat transfer coefficient

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.The effect of different coatings painted on the heat transfer surface of the horizontal heater in a vertical fluidized bed heat transfer unit is studied. Polyurethane and polyurethane based zinc coatings are applied on the horizontal heat transfer surfaces and their effects on the heat transfer coefficient are investigated for different heater heights, different heater heat inputs and for different superficial velocities. It is found that the application of polyurethane coatings has decreased the heat transfer coefficient as compared to the heat transfer coefficient obtained with the bare uncoated heater. It is also found that by applying the polyurethane based zinc coatings the heat transfer coefficient has increased as compared to that obtained with the polyurethane coating. Procedure and the results of the experiments done to study this fluidized bed heat transfer analysis are presented in this paper

Chiral topological add–drop filter for integrated quantum photonic circuits

The integration of quantum emitters within topological nanophotonic devices enables the control of light–matter interactions at the single photon level. Here, we experimentally realize an integrated topological add–drop filter and observe multiport chiral emission from single photon emitters (quantum dots) embedded within the device. The filter is imprinted within a valley-Hall photonic crystal membrane and comprises a resonator evanescently coupled to a pair of access waveguides. We show that the longitudinal modes of the resonator enable the filter to perform wavelength-selective routing of light, protected by the underlying topology. Furthermore, we demonstrate that for a quantum dot located at a chiral point in the resonator, selective coupling occurs between well-defined spin states and specific pairs of the filter output ports. The combination of multiport routing, allied with the inherent nonreciprocity of the device at the single photon level, presents opportunities for the formation of complex quantum optical devices, such as an on-chip quantum optical circulator

A semiconductor topological photonic ring resonator

Unidirectional photonic edge states arise at the interface between two topologically distinct photonic crystals. Here, we demonstrate a micrometer-scale GaAs photonic ring resonator, created using a spin Hall-type topological photonic crystal waveguide. Embedded InGaAs quantum dots are used to probe the mode structure of the device. We map the spatial profile of the resonator modes and demonstrate the control of the mode confinement through tuning of the photonic crystal lattice parameters. The intrinsic chirality of the edge states makes them of interest for applications in integrated quantum photonics, and the resonator represents an important building block toward the development of such devices with embedded quantum emitters

A chiral topological add-drop filter for integrated quantum photonic circuits

The integration of quantum emitters within topological nano-photonic devices opens up new avenues for the control of light-matter interactions at the single photon level. Here, we realise a spin-dependent, chiral light-matter interface using individual semiconductor quantum dots embedded in a topological add-drop filter. The filter is imprinted within a valley-Hall photonic crystal (PhC) membrane and comprises a resonator evanescently coupled to a pair of access waveguides. We show that the longitudinal modes of the resonator enable the filter to perform wavelength-selective routing of light, protected by the underlying topology. Furthermore, we demonstrate that for a quantum dot located at a chiral point in the resonator, selective coupling occurs between well-defined spin states and specific output ports of the topological device. This behaviour is fundamental to the operation of chiral devices such as a quantum optical circulator. Our device therefore represents a topologically-protected building block with potential to play an enabling role in the development of chiral integrated quantum photonic circuits

Structural, magnetic and electrical properties of single crystalline La_(1-x)Sr_xMnO_3 for 0.4 < x < 0.85

We report on structural, magnetic and electrical properties of Sr-doped LaMnO_3 single crystals for doping levels 0.4 < x < 0.85. The complex structural and magnetic phase diagram can only be explained assuming significant contributions from the orbital degrees of freedom. Close to x = 0.6 a ferromagnetic metal is followed by an antiferromagnetic metallic phase below 200 K. This antiferromagnetic metallic phase exists in a monoclinic crystallographic structure. Following theoretical predictions this metallic antiferromagnet is expected to reveal an (x^2-y^2)-type orbital order. For higher Sr concentrations an antiferromagnetic insulator is established below room temperature.Comment: 8 pages, 7 figure

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society