Potentials of leaves of Aspilia africana (Compositae) in wound care: an experimental evaluation

<p>Abstract</p> <p>Background</p> <p>The potentials of the leaves of the haemorrhage plant, <it>Aspilia africana </it>C. D Adams (Compositae) in wound care was evaluated using experimental models. <it>A. africana</it>, which is widespread in Africa, is used in traditional medicine to stop bleeding from wounds, clean the surfaces of sores, in the treatment of rheumatic pains, bee and scorpion stings and for removal of opacities and foreign bodies from the eyes. The present study was undertaken to evaluate the potentials for use of leaves of this plant in wound care.</p> <p>Methods</p> <p>The effect of the methanol extract (ME) and the hexane (HF) and methanol (MF) fractions (obtained by cold maceration and graded solvent extraction respectively) on bleeding/clotting time of fresh experimentally-induced wounds in rats, coagulation time of whole rat blood, growth of microbial wound contaminants and rate of healing of experimentally-induced wounds in rats were studied as well as the acute toxicity and lethality (LD₅₀) of the methanol extract and phytochemical analysis of the extract and fractions.</p> <p>Results</p> <p>The extract and fractions significantly (<it>P </it>< 0.05) reduced bleeding/clotting time in rats and decreased coagulation time of whole rat blood in order of magnitude of effect: MF>ME>HF. Also, the extract and fractions caused varying degrees of inhibition of the growth of clinical isolates of <it>Pseudomonas fluorescens </it>and <it>Staphylococcus aureus</it>, as well as typed strains of <it>Ps. aeruginosa </it>(ATCC 10145) and <it>Staph. aureus </it>(ATCC 12600), and reduced epithelialisation period of wounds experimentally-induced in rats. Acute toxicity and lethality (LD₅₀) test in mice established an i.p LD₅₀of 894 mg/kg for the methanol extract (ME). Phytochemical analysis revealed the presence of alkaloids, saponins, tannins, flavonoids, resins, sterols, terpenoids and carbohydrates.</p> <p>Conclusion</p> <p>The leaves of <it>A. africana </it>possess constituents capable of arresting wound bleeding, inhibiting the growth of microbial wound contaminants and accelerating wound healing which suggest good potentials for use in wound care.</p

Can Ultrasound or pH Influence Pd Distribution on the Surface of HAP to Improve Its Catalytic Properties in the Dry Reforming of Methane?

The influence of ultrasound and different pH pre-treatments during the metal doping/modification of a hydroxyapatite (HAP) support is investigated. HAP is first synthesised via a hard-template synthetic route using carbon nanorods followed by their full physiochemical characterisation. The HAP was found to be crystalline and comprised a mesoporous structure as observed via XRD and nitrogen adsorption with a BET surface area of 97.57 (±1.16) m2 g−1. Ultrasound-assisted ion exchange (IE) and incipient wetness impregnation (IW) methodologies were employed to decorate the surface of HAP with Pd0 and are compared to previous procedures. The influence of pH upon the distribution of Pd0 throughout the samples during the doping process is also studied. All the prepared samples were evaluated for their catalytic activity towards dry reforming of methane (DRM) and the reaction was monitored via a thermal conductivity detector, coupled with gas chromatography (GC-TCD). It was found that ultrasound-assisted IE significantly accelerated the process from 3 days to 3 h and with the Pd0 metal remaining highly distributed upon the HAP with minor changes in catalytic conversions. Moreover, the ultrasound-assisted IW method successfully improved the Pd0 distribution and catalytic performance. On the other hand, the dispersion of the metal was unaffected after pH treatments in IE with no catalytic improvements observed, in contrast to IW, where considerable increase in metal distribution and subsequently catalytic performance was observed

Search for gravitational waves associated with gamma-ray bursts detected by Fermi and Swift during the LIGO–Virgo run O3b

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC–2020 March 27 17:00 UTC). We conduct two independent searches: a generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate

Particle identification in ALICE : a Bayesian approach

Peer reviewe

K*(892)(0) and phi(1020)meson production at high transverse momentum in pp and Pb-Pb collisions at root sNN=2.76 TeV

The production of K∗(892)0 and φ(1020) mesons in proton-proton (pp) and lead-lead (Pb-Pb) collisions at √sNN = 2.76 TeV has been analyzed using a high luminosity data sample accumulated in 2011 with the ALICE detector at the Large Hadron Collider (LHC). Transverse momentum (pT) spectra have been measured for K∗(892)0 and φ(1020) mesons via their hadronic decay channels for pT up to 20 GeV/c. The measurements in pp collisions have been compared to model calculations and used to determine the nuclear modification factor and particle ratios. The K∗(892)0/K ratio exhibits significant reduction from pp to central Pb-Pb collisions, consistent with the suppression of the K∗(892)0 yield at low pT due to rescattering of its decay products in the hadronic phase. In central Pb-Pb collisions the pT dependent φ(1020)/π and K∗(892)0/π ratios show an enhancement over pp collisions for pT ≈ 3 GeV/c, consistent with previous observations of strong radial flow. At high pT, particle ratios in Pb-Pb collisions are similar to those measured in pp collisions. In central Pb-Pb collisions, the production of K∗(892)0 and φ(1020) mesons is suppressed for pT &gt; 8 GeV/c. This suppression is similar to that of charged pions, kaons, and protons, indicating that the suppression does not depend on particle mass or flavor in the light quark sector

Production, characterization and prediction of mechanical properties of waste fibre reinforced composite panels for application in adjustable partition walls of buildings

In the present paper, waste fibre reinforced composite panels have been developed for application in interior partition walls of buildings. These panels were produced using waste fibres collected from the textile industries and using aminoplastic phenol-formaldehyde resin. Mechanical properties such as tensile, compression and flexural properties of these composite panels were characterized and the influence of a few parameters such as fibre or matrix weight % and composite density on the mechanical properties has been analyzed. Impact properties (soft body and hard body impact), which is very important for the materials used in the partition walls, of the developed composite panels was simulated using finite element method and the influence of composite parameters (fibre or resin content, composite density) on the impact resistance and strain energy was analyzed. Thermal degradation behaviour of the developed composite panels was also investigated. Although the waste fibre reinforced composites show low mechanical properties, the simulation results showed that the composite panels showed required impact properties (no collapse, no penetration or projection under both soft and hard body impact) for their successful application in the interior partition walls. Thermal stability of the composite panels was also sufficient for this application. It was also observed that the composite panels exhibited better impact resistance and lower deformation when produced with higher fibre % as well as higher density.FCT - Fundação para a Ciência e a Tecnologia()info:eu-repo/semantics/publishedVersio

Modification of natural polymers: Part I—Ceric ion initiated graft <span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:#181818;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI">copolymerization of methyl methacrylate <span style="font-size:14.0pt;line-height:115%;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";color:#2C2C2C; mso-ansi-language:EN-IN;mso-fareast-language:EN-IN;mso-bidi-language:HI">onto <i><span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:#181818;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI">Cannabi<span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:#474747;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI">s </span></span></i><span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:#2C2C2C;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI">fibre</span></span></span>

269-275Ceric ion initiated graft copolymerization of methyl methacrylate onto Cannabis indica fibre has been carried out. Optimum grafting conditions such as the concentrations of monomer, initiator and nitric acid, amount of water, reaction time and reaction temperature have been evaluated. The grafted copolymers and the ungrafted Cannabis fibre have been characterized by IR spectroscopy, thermal gravimetric analysis and swelling studies in DMF, water and n-butanol. The trend in the swelling behaviour of the grafted samples (DMF > water> n-butanol) is different from that observed for the ungrafted sample- (water > DMF > n-butanol). The grafted samples show improved thermal stability in contrast to ungrafted fibre. The plausible mechanism for grafting reactions is suggested and the explanation for the trends in grafting parameters are given

Tensile strength of pine needles and their feasibility as reinforcement in composite materials

A feasibility study concerning the use of pine needles from Maritime Pine (Pinus pinaster) trees as reinforcement in composite materials has been presented in this paper with the tensile strength being investigated for a total of 150 specimens at three gauge lengths, namely 50, 75 and 100 mm. In order to calculate the tensile strength for each specimen, a correlation was obtained between the cross-sectional area and external dimensions of the individual pine needles. The mean value of the tensile strength was noted to vary only slightly between 33.4 MPa for the 50 mm gauge length and 31.4 MPa for the 100 mm case with a minimum and maximum of 15 and 65 MPa, respectively. Analysis of the data using the standard Weibull model indicated the Weibull strength to vary between 33.5 and 36.0 MPa whereas the Weibull modulus varied between approximately 3.5 and 4.5. Further analysis using the Weibull model indicated the presence of a bimodal strength distribution at each gauge length that was consistent with the presence of two distinct flaw populations operating within the pine needles. Overall, it was concluded that the strength of the pine needles was sufficient for inclusion in polymer matrix composites subject to low stress or non-load bearing applications such as fibreboard and thermal or acoustic insulation