Preparation and Characterization of Hydroxyapatite-Alumina-Zirconia Composite

In this present work, hydroxyapatite-alumina-zirconia composites were prepared and subsequent characterization was performed. This work makes zirconia as a central layer, alumina as an intermediate layer and then hydroxyapatite as an outer shell. The resultant composite was expected to have both improved mechanical properties and improved phase purity because of separation of two reactive phases, zirconia and hydroxyapatite by the alumina layer. In the first step of work synthesis of hydrous zirconia was prepared by using zirconium oxychloride and ammonium hydroxide solution and from it stabilization of tetragonal zirconia was performed after doping 3mol% Y2O3 during synthesis of hydrous zirconia. Treating yttria stabilized zirconia (YSZ) as core and using urea as the precipitant, subsequent coating on particle surface was performed in two steps, first aluminum nitrate as the source of Al3+ to generate alumina coating on YSZ and secondly using calcium nitrate as a source of Ca2+ and diammonium hydrogen phosphate as the source of P(Ca/P ratio 1.67) to produce hydroxyapatite coating on top of alumina coating on YSZ. Layered coating was ensured by drop wise addition of aluminum nitrate solution on zirconia precipitate and the similar procedure was followed for coating of hydroxyapatite on ZrO2-Al2O3 particles synthesized using urea decomposition method above 85oC in aqueous media. The resultant precipitate was freeze dried and then calcined at 800oC/4h followed by compaction of calcined powder into pellets and sintering at 1300oC. Particle size distribution, phase composition and microstructural analysis of sintered compacts were performed using TEM, XRD and FESEM respectively

Appraisal of phytochemical and antibacterial potential of Myrica nagi Willd. extracts against respiratory tract pathogens

In the present study the antibacterial activity was studied against five bacterial pathogens i.e. Haemophilus influenzae MTCC 3826, Pseudomonas aeruginosa MTCC 2474, Staphylococcus aureus MTCC 1144, Streptococcus pneumoniae MTCC 655 and Streptococcus pyogenes MTCC 442. Shade dried root were crushed and extracted in petroleum ether (PET), acetone (ACE), methanol (MeOH) and water (H2O) by using Soxhlet apparatus. The agar well diffusion method was adopted to examine antibacterial activity of extracts against the susceptible organisms. Erythromycin was used as positive control to determine the sensitivity of the strains. Phytochemical analysis was done for plant extract. The results showed that MeOH extract was most active as comparison to other extract. The maximum inhibition was found against H. influenzae (18.4±0.07 mm) followed by S. pyogenes (17.3±0.13 mm), S. pneumoniae (16.2±0.07 mm) and P. aeruginosa (15.5±0.15 mm) respectively. The minimum inhibition was noted against S. aureus (14.4±0.13 mm). The phytochemical screening for MeOH extract has shown that plant contains flavonoids, glycosides, alkaloids, steroids, terpene, saponins and tannins. Therefore, M. nagi can be helpful as an alternative source of medicine and new drug discovery

Natural products as leads to potential mosquitocides

Mosquitoes are the crucial vectors for a number of mosquito-borne infectious diseases i.e. dengue, yellow fever, chikungunya, malaria, Rift Valley fever, elephantiasis, Japanese Encephalitis, and Murray Valley encephalitis etc. Besides, they also transmit numerous arboviruses (arthropod-borne viruses) for example West Nile virus, Saint Louis encephalitis virus, Eastern equine encephalomyelitis virus, Everglades virus, Highlands J virus, and La Crosse Encephalitis virus. The emergence of widespread insecticide resistance and the potential environmental issues associated with some synthetic insecticides (such as DDT) has indicated that additional approaches to control the proliferation of mosquito population would be an urgent priority research. The present review highlights some natural product mosquitocides that are target-specific, biodegradable, environmentally safe, and botanicals in origin.Department of Plant Science, University of Pretoria, South Africa, Department of Chemistry, Banaras Hindu University,India and National Research Foundation.http://link.springer.com/journal/11101hb201

Comparative evaluation of shock absorption ability of custom-fit mouthguards with new-generation polyolefin self-adapting mouthguards in three different maxillary anterior teeth alignments using Fiber Bragg Grating (FBG) sensors

Prevention of orofacial injuries is one of the biggest pre-occupations in sports dentistry. The custom-fitted mouthguard is considered the best choice for fit and protection when compared to over-the-counter commercial mouthguards. However, cost and time prohibit their mass production. It is therefore imperative to have an over-the-counter true mouth-formed mouthguard with comparable properties. The present in vitro experimental study was carried out to compare the shock absorption ability of EVA laminate mouthguards with self-adapting polyolefin material mouthguards in three different anterior teeth alignments

Elementals Profile Of Traditional Some Important Medicinal Plants Of Uttarakhand State, India

Abstract: The life on the earth depends upon two types of chemical reactions such as the photosynthesis and respiration. Metal ions play a vital role in both the reactions. Mineral elements are nutrients which are found in foods and which are essential to the body in microscopic amounts. The inorganic constituent's viz., Fe, K, Mg, Ca, Cu, Zn, Ni, Co and chloride, sulphate, inorganic phosphorus, organic phosphorus and total phosphorus of Jasminum grandiflorum, Vitex negundo, Salvadora persica, Anacyclus pyrethrum and Olea europaea were determined by using AAS (Atomic Absorption Spectroscopy). These plants are traditionally used for nervous and urinary diseases, disorder of the blood and bile, dental, cooling, tonic, chronic bowel complaints, fever, headache, ulcer and worms. [Report and Opinion 2010;2(6):34-36]. (ISSN:1553-9873)

Ultrasound for Improved Crystallisation in Food Processing

Within the food industry, controlling crystallisation is a key factor governing food structure, texture and consumer appeal, with some foods requiring the promotion of crystallisation in a controlled manner (e.g. chocolate) and others a check (e.g. in honey). Sonocrystallisation is the application of ultrasound energy to control the nucleation of a crystallisation process. The use of power ultrasound provides a non-invasive approach to producing crystals with desired properties. Sonocrystallisation facilitates process control, primarily by modulating crystal size distribution and morphology. This paper details the governing mechanisms of sonocrystallisation. Proven and potential applications of the process in foods, including chocolates, honey, fats and frozen foods are reviewed. Challenges of process adoption such as scale-up are discussed