328 research outputs found

    Laser Textured Calcium Phosphate Bio-Ceramic Coatings on Ti-6Al-4V for Improved Wettability and Bone Cell Compatibility

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    The interaction at the surfaces of load bearing implant biomaterials with tissues and physiological fluids is an area of crucial importance to all kinds of medical technologies. To achieve the best clinical outcome and restore the function of the diseased tissue, several surface engineering strategies have been discussed by scientific community throughout the world. In the current work, we are focusing on one such technique based on laser surface engineering to achieve the appropriate surface morphology and surface chemistry. Here by using a pulsed and continuous wave laser direct melting techniques we synthesize three dimensional textured surfaces of calcium phosphate (Ca-P) based surface chemistry on Ti-6Al-4V. The influence of each processing type on the micro texture and phase evolution and thereby its associated effect on wettability, in vitro bioactivity, and in vitro biocompatibility are systematically discussed. For samples processed using the pulsed laser, it was realized that with increasing laser scan speed and laser pulse frequency there was a transition from surface textures with sharp circular grooves to surface textures with radial grooves and thereby improved hydrophilicity. For CW laser processing the results demonstrated improved hydrophilicity for the samples processed at 100 μm line spacing as compared to the samples processed at 200 μm line spacing. Owing to the importance of Si for cartilage and hard tissue repair, a preliminary effort for synthesizing Ca-P-SiO2 composite coating on Ti-6Al-4V surface were also conducted. As a future potential technique we also explored the Laser Interference Patterning (LIP) technique to achieve the textured surfaces and developed understanding on their wetting behavior. In the current work, by adjusting the laser processing parameters we were able to synthesize textured coatings with biocompatible phases. The in vitro bioactivity and in vitro vi biocompatibility of the coatings were proved by the precipitation of an apatite like phase following immersion in simulated body fluid (SBF), and increased proliferation and spreading of the MC3T3-E1 like cells. The results and understanding of the current research is encouraging in terms of looking at other bio-ceramic precursor compositions and laser process parameter window for synthesizing better textured biocompatible coatings

    μ-Acetato-μ-(5-chloro-2-{1,3-bis[2-(5-chloro-2-oxidobenzylideneamino)ethyl]imidazolidin-2-yl}phenolato)-bis[methanolnickel(II)] methanol monosolvate monohydrate

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    The crystal structure shows that the title compound, [Ni2(CH3CO2)(C27H24Cl3N4O3)(CH4O)2]·CH3OH·H2O, con­tains [Ni2 L(OAc)(CH3OH)2] mol­ecules in the unit cell {H3 L = 5-chloro-2-{1,3-bis[2-(5-chloro-2-oxidobenzylideneimino)-ethyl]imidazolidin-2-yl}phenolate} with water and methanol as solvates. The title compound is a neutral dinuclear compound, in which the L 3− Schiff base acts as a hepta­dentate ligand, using each one of its N2O compartments to coordinate a nickel atom. The acetate anion bridges the two nickel atoms via one O while the distorted octahedral coordination sphere for each nickel atom is completed by a coordinated methanol ligand. One of the coordinated methanol ligands is involved in an intra­molecular hydrogen bond to the uncoordinated O atom of the bridging acetate ligand while the other forms a hydrogen bond with the methanol solvate. The solvate water mol­ecule forms strong hydrogen bonds to both terminal phenolato O atoms. The methanol solvate mol­ecule also forms a hydrogen bond with the water solvate mol­ecule

    μ-Acetato-aqua-μ-(5-bromo-2-{1,3-bis­[2-(5-bromo-2-oxidobenzyl­idene­amino)­eth­yl]imidazolidin-2-yl}phenolato)methano­ldinickel(II) methanol disolvate monohydrate

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    The crystal structure of the title compound, [Ni2(C27H24Br3N4O3)(CH3CO2)(CH3OH)(H2O)]·2CH3OH·H2O contains [L(OAc){(CH3OH)Ni}{(H2O)Ni}] mol­ecules {H3 L = 2-(5-bromo-2-hy­droxy­phen­yl)-1,3-bis­[4-(5-bromo-2-hy­droxy­phen­yl)-3-aza­but-3-en­yl]-1,3-imidazolidine} with additional water and two methanol solvent mol­ecules. In this instance, one of the two Ni atoms is coordinated to a water and the other to a methanol mol­ecule. The Ni—O and Ni—N distances, as well as the angles about the metal atoms, show quite regular octa­hedra around the central ions. The Ni—Ophenol—Ni and Ni—Oacetate—Ni angles are not similar [95.26 (13) and 97.34 (13)°, respectively], indicating that this subtle solvate exchange induces significant differences in the conformation adopted. The coordinated methanol ligand is involved in an intra­molecular hydrogen bond to the uncoordinated O atom of the bridging acetate ligand, while the coordinated water mol­ecule forms a hydrogen bond with the one of the methanol solvent mol­ecules. The water solvent mol­ecule forms strong hydrogen bonds to both phenolate O atoms. The remaining methanol solvent mol­ecule also forms a hydrogen bond with this solvent water mol­ecule

    A CASE REPORT ON BENIGN PROSTATIC HYPERPLASIA WITH HOMEOPATHIC REMEDIES

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    Benign prostatic hyperplasia (BPH) is characterized by proliferation of the cellular elements of the prostate. The complications faced by elderly people need to be minimized and most of elderly don not prefer a surgical approach. Therefore, treatment of BPH with medicines is prioritized by elderly people. The present case report adds a little to the field that how to treat BPH cases in elderly without surgical approach but with homeopathic formulations. Case report presented here is diagnosed case of BPH having grade III prostatomegaly on USG. Patient presented with increased frequency of urination in feeble stream and sudden urging occasionally. Patient was treated with homoeopathic medication and assessed using Ultrasonography, International Prostate Symptom Score, and Uroflowmetry with significant improvement. Hence, it is suggestive that homoeopathic treatment could be effective in the management of cases of BPH in elderly people. Keywords: Homoeopathy, BPH, Uroflowmetry, International Prostate Symptom Score (IPSS), Constitutional medicine, Organopathic medicine, Sabal serrulat

    Bacterial Foraging Optimized STATCOM for Stability Assessment in Power System

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    This paper presents a study of improvement in stability in a single machine connected to infinite bus (SMIB) power system by using static compensator (STATCOM). The gains of Proportional-Integral-Derivative (PID) controller in STATCOM are being optimized by heuristic technique based on Particle swarm optimization (PSO). Further, Bacterial Foraging Optimization (BFO) as an alternative heuristic method is also applied to select optimal gains of PID controller. The performance of STATCOM with the above soft-computing techniques are studied and compared with the conventional PID controller under various scenarios. The simulation results are accompanied with performance indices based quantitative analysis. The analysis clearly signifies the robustness of the new scheme in terms of stability and voltage regulation when compared with conventional PID

    Bacterial Foraging Optimized STATCOM for Stability Assessment in Power System

    Get PDF
    This paper presents a study of improvement in stability in a single machine connected to infinite bus (SMIB) power system by using static compensator (STATCOM). The gains of Proportional-Integral-Derivative (PID) controller in STATCOM are being optimized by heuristic technique based on Particle swarm optimization (PSO). Further, Bacterial Foraging Optimization (BFO) as an alternative heuristic method is also applied to select optimal gains of PID controller. The performance of STATCOM with the above soft-computing techniques are studied and compared with the conventional PID controller under various scenarios. The simulation results are accompanied with performance indices based quantitative analysis. The analysis clearly signifies the robustness of the new scheme in terms of stability and voltage regulation when compared with conventional PID

    Modulating calcium phosphate formation using CO2 laser engineering of a polymeric material

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    The use of simulated body fluid (SBF) is widely used as a screening technique to assess the ability of materials to promote calcium phosphate formation. This paper details the use of CO2 laser surface treatment of nylon® 6,6 to modulate calcium phosphate formation following immersion in SBF for 14 days. Through white light interferometry (WLI) it was determined that the laser surface processing gave rise to maximum Ra and Sa parameters of 1.3 and 4.4 µm, respectively. The use of X-ray photoelectron spectroscopy (XPS) enabled a maximum increase in surface oxygen content of 5.6 %at. to be identified. The laser-induced surface modifications gave rise to a modulation in the wettability characteristics such that the contact angle, θ, decreased for the whole area processed samples, as expected, and increased for the patterned samples. The increase in θ can be attributed to a transition in wetting nature to a mixed-state wetting regime. It was seen for all samples that calcium phosphate formed on each surface following 14 days. The largest increase in mass, Δg, owed to calcium phosphate formation, was brought about by the whole area processed sample irradiated with a fluence of 51 Jcm-2. No correlation between the calcium phosphate formation and the laser patterned surface properties was determined due to the likely affect of the mixed-state wetting regime. Strong correlations between θ, the surface energy parameters and the calcium phosphate formation for the whole area processed samples allow one to realize the potential for this surface treatment technique in predicting the bone forming ability of laser processed materials

    Daily Dietary Nutrition and Nutraceutical Intake in Agricultural Laborers of Hirakud Command Area, Sambalpur, Odisha, India

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    Sambalpur is considered as the rice bowl of Odisha for its cultivation activities due to the presence of hydroelectric power house Hirakud Dam, with total capacity of  5,896,000,000 m3, 55 km long and is one of the first major multipurpose river valley projects started after India's independence. It irrigates about 75,000 km2 (19×106 acres) of land and therefore, is considered as a blessing to the farmer families. As because of cultivation and allied activities, Agricultural Laborers (ALs) constitute a large portion of the active work force. Study on the nutritional intake in this important fraction of population is lacking. Present study was an attempt to know the food consumption pattern and nutritional intakes of ALs in Hirakud command area of Sambalpur district, India. Data were collected from 300 ALs, consisting of 150 from each gender. Daily dietary pattern and nutritional intake of respondent were calculated through 24 hours dietary recall method. It was observed that ALs consume all most all the food varieties available in Odisha. Cereal consumption was 6.80 and 1.77 % excess than the recommend value dietary allowance (RDA) by Indian Council for Medical Research (ICMR, in 1990). Except cereals, all other food consumption was below the RDA value in ALs. The intake of other food varieties in ALs was > 60% deficit from the RDA values. Consumption of milk was 97% less in case of male ALs and 98 % less in case of female ALs in comparison to the values suggested in RDA. Similarly, consumption of all nutrients was less than RDA norms except Vitamin -C in case of male ALs. The consumption of Niacin and Vitamin -C was excess in case of female ALs. Alternate low cost food supply is suggested to compensate such insufficient nutritional uptake by ALs in the study area. Keywords: Food, nutrient intake, nutraceuticals, nutritional status, 24 hours recall metho

    Wettability and osteoblast cell response modulation through UV laser processing of nylon 6,6

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    With an ageing population the demand for cheap, efficient implants is ever increasing. Laser surface treatment offers a unique means of varying biomimetic properties to determine generic parameters to predict cell responses. This paper details how a KrF excimer laser can be employed for both laser-induced patterning and whole area irradiative processing to modulate the wettability characteristics and osteoblast cell response following 24 hour and 4 day incubation. Through white light interferometry (WLI) it was found that the surface roughness had considerably increased by up to 1.5 µm for the laser-induced patterned samples and remained somewhat constant at around 0.1 µm for the whole area irradiative processed samples. A sessile drop device determined that the wettability characteristics differed between the surface treatments. For the patterned samples the contact angle, θ, increased by up to 25° which can be attributed to a mixed-state wetting regime. For the whole area irradiative processed samples θ decreased owed to an increase in polar component, γP. For all samples θ was a decreasing function of the surface energy. The laser whole area irradiative processed samples gave rise to a distinct correlative trend between the cell response, θ and γP. However, no strong relationship was determined for the laser-induced patterned samples due to the mixed-state wetting regime. As a result, owed to the relationships and evidence of cell differentiation one can deduce that laser whole area irradiative processing is an attractive technology for employment within regenerative medicine to meet the demands of an ageing population

    1,4-Dibut­oxy-2,5-bis­{(Z)-2-[4-(9H-carbazol-9-yl)phen­yl]ethen­yl}benzene

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    The title compound, C54H48N2O2, lies about an inversion centre. The carbazole ring system makes dihedral angles of 58.43 (7) and 88.96 (7)°, respectively, with the adjacent and central benzene rings. The dihedral angle between the two benzene rings is 52.01 (8)°. In the crystal, mol­ecules are linked by pairs of C—H⋯O inter­actions, forming a tape along the a axis. The methyl group is disordered over two sets of sites with occupancies of 0.63 (3) and 0.37 (3)
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