Structural transition and enhanced phase transition properties of Se doped Ge₂Sb₂Te₅ alloys

Amorphous Ge₂Sb₂Te₅ (GST) alloy, upon heating crystallize to a metastable NaCl structure around 150°C and then to a stable hexagonal structure at high temperatures (≥250°C). It has been generally understood that the phase change takes place between amorphous and the metastable NaCl structure and not between the amorphous and the stable hexagonal phase. In the present work, it is observed that the thermally evaporated (GST)1-xSex thin films (0 ≤ x ≤ 0.50) crystallize directly to the stable hexagonal structure for x ≥ 0.10, when annealed at temperatures ≥ 150°C. The intermediate NaCl structure has been observed only for x < 0.10. Chemically ordered network of GST is largely modified for x ≥ 0.10. Resistance, thermal stability and threshold voltage of the films are found to increase with the increase of Se. The contrast in electrical resistivity between the amorphous and crystalline phases is about 6 orders of magnitude. The increase in Se shifts the absorption edge to lower wavelength and the band gap widens from 0.63 to 1.05 eV. Higher resistance ratio, higher crystallization temperature, direct transition to the stable phase indicate that (GST)1-xSex films are better candidates for phase change memory applications.

Enhanced catalytic and antibacterial activities of silver nanoparticles immobilized on poly(N-vinyl pyrrolidone)-grafted graphene oxide

PNVP grafted on GO regulates the size of Ag nanoparticles and enhances the catalytic and antibacterial properties along with increase in the dispersibility of GO.

A novel one pot four-component reaction for the efficient synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-3′-carboxylate and trifluoromethylated spiro[indole-3,4′-pyrano[2,3-c]pyrazole] derivatives using recyclable PEG-400

A novel, simple and efficient synthetic protocol has been developed via a one pot, four-component reaction using recyclable PEG-400.

Tadpole-shaped β-cyclodextrin-tagged poly(N-vinylpyrrolidone): synthesis, characterization and studies of its complexation with phenolphthalein and anti tumor activities

DOX-loaded β-CD-PNVP shows more effective delivery of DOX compared to free DOX towards the U2-OS, MCF-7 and HEPG2 cell lines.

N-succinyl chitosan preparation, characterization, properties and biomedical applications: a state of the art review

N-succinyl chitosan (NSC) remains a promising chitosan derivative to develop targeted drug delivery, wound dressings, and tissue engineering systems. All these systems are important in life sciences. NSC is an amphiprotic derivative obtained from the N-acylation of chitosan. NSC exhibits extraordinary biocompatibility, significantly increased aqueous solubility in acidic and basic media without affecting the biological properties, appreciable transfection efficiency, and the ability to stimulate osteogenesis. NSC shows enhanced bioavailability, which highlights its potential applications in the biomedical field. This review briefly introduces chitosan, including its limitations as a biomaterial, and modifications of chitosan with a particular focus on acylation, along with a comprehensive overview of the synthesis, characterization, properties, biodistribution, and toxicological/biopharmaceutical profile of NSC. Furthermore, it extensively surveys current state-of-the-art NSC-based formulations for drug delivery with special emphasis on protein delivery, anti-cancer activity in the colon, as well as nasal and ophthalmic targeted gene/drug delivery. Moreover, it discusses NSC-based biomaterial applications in articular, adipose, and bone tissue engineering. In addition, it describes recent contributions of NSC-based hydrogels in wound dressings along with a brief account of drug delivery in combination with tissue engineering. Finally, it presents potential current challenges and future perspectives of NSC-based formulations in the biomedical field.

Study of Efficacy and the Comparison Between 2.0 mm Locking Plating System and 2.0 mm Standard Plating System in Mandibular Fractures

PURPOSE

The purpose of this study was to evaluate the efficacy and comparison between 2.0 mm locking plate system and 2.0 mm Champy's titanium mini plating system in mandible fractures.

MATERIALS AND METHODS

A total of 20 patients with mandibular fractures were selected and divided into two groups A and B on randomized basis. Group A was treated with open reduction internal fixation using 2.0 mm locking plates and group B with 2.0 mm Champy's titanium miniplates. All patients were followed up for 12 weeks postoperatively.

RESULTS

Results of the study show less screw loosening, less precision in plate adaptation and less alteration of the osseous or occlusal relationship upon screw tightening in group A. Chi square test was applied to compare the results between the two groups. Statistical analysis did not show significant difference of incidence of malocclusion between the two groups (p value = 0.606). Statistical analysis using un-paired t test showed significant difference of working time between the two groups (p value = 0.00296). When comparing the overall complication rates according to plates used, the χ(2) test showed no statistically significant difference between the locking and nonlocking plates (p > 0.05).

CONCLUSION

It is observed in our study that the locking plate/screw system offers significant advantages over the conventional plating system. The precise adaptation required for using conventional plates is not needed when this locking plate/screw system is used. Locking plate/screw system provides better stability than the conventional plate/screw system.

Design, statistical optimisation, characterisation and pharmacodynamic studies on Pioglitazone hydrochloride floating microparticles

The purpose of this study was to develop floating microparticles containing Pioglitazone HCl, for controlled release and perform pharmacodynamic studies. The FTIR and DSC studies revealed that there is no interaction between drug and excipients used. The 2(2) factorial design was employed to evaluate the effect of drug: polymer (total) and Eudragit RS 100: Eudragit RL 100. The floating microparticles were prepared by solvent evaporation technique. The predicted and actual values of drug release at 1 h, 8 h and drug entrapment were 38.307%, 77.76%, 84.25% and 38.712%, 76.237% and 84.62%, respectively. XRD and SEM studies showed reduced crystallinity of drug and spherical microparticles. Buoyancy studies revealed good floating of particles for 12 h. Pharmacodynamic studies showed significant reduction in blood glucose levels in male New Zealand rabbits. The results demonstrate the feasibility of the factorial design in successfully developing floating microparticles of Pioglitazone HCl for controlled release.

Development and evaluation of flavi-immunoglobulin M capture enzyme-linked immunosorbent assay

In this study, we report the evaluation of In-house flavi virus immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (ELISA), which can be used as a screening test to determine the infecting flavivirus serotype over the current serological methods. A panel of 88 sera (inclusive of well characterized dengue, Japanese Encephalitis (JE) and West Nile virus (WNV) positive and negative samples tested and confirmed by commercial kit) was used for evaluation of the kit. The sensitivity and specificity of the In-house capture assay versus the commercial kit for the sero-diagnosis of dengue was 100% and 87% respectively, for JE IgM, it was found to be 90% and 100% respectively, and for West Nile it was 87.5% and 90.9%. Based on the study, we concluded that this flavivirus-serotyping ELISA provides rapid results and may be used as an accurate alternate to other serological tests for the specific diagnosis of flavivirus infections.

Alternaria alternata in a case of mass in the lung

A 50-year-old woman, an agriculture worker with diabetes and asthma presented to us with complaints of fever with chills, cough with scanty, mucopurulent sputum and dull aching chest pain in right mammary area radiating to axilla. Chest X-ray and computed tomography scan revealed mass in the right lung. Ultrasound guided fine-needle aspiration cytology was done and the greenish fluid on direct wet mount and inoculation on Sabouraud's dextrose agar isolated Alternaria species. Serum specimen was evaluated for immunoglobulin E specific titres for Alternaria species which was high. Patient was treated with fluconazole for 6 weeks after which the symptoms disappeared and chest X-ray was normal.

Evaluation of the efficacy of probiotics in plaque reduction and gingival health maintenance among school children - A Randomized Control Trial

BACKGROUND

Probiotics are live micro-organisms that when administered in adequate amounts confer health benefits upon the host. The impact of probiotics on oral health is relatively new with lots of research going on; the area of probiotics and periodontal disease is still in its infancy. The aim of the present trial was to evaluate the efficacy of the probiotics in plaque reduction among school children.

MATERIALS & METHODS

This is a randomized, double-blind, placebo controlled parallel design study involving 216 school children (aged 14 - 17 years): 108 as experimental subjects and 108 as controls. Complete oral prophylaxes were performed for both the control group and experimental group. The pre-intervention plaque index and gingival index were recorded one week after the prophylaxis for both groups as the baseline data. The study subjects (Group A) included curd in their daily diet for 30 days, while the control subjects (Group B) excluded curd in their diet for 30 days. The post intervention plaque index and gingival index were recorded again and statistically compared with the baseline data.

RESULTS

the intervention group (Group A) was found to have statistically significant reduction in plaque when compared to that of the control group with p <0.001 and there was no significant improvement in gingival health.

CONCLUSION

A short-term daily ingestion of probiotics delivered via curd in diet reduced the levels of plaque. Hence if it can be promoted in the regular diet, it would help in improving the oral health among school children. How to cite this article: Karuppaiah RM, Shankar S, Raj SK, Ramesh K, Prakash R, Kruthika M. Evaluation of the efficacy of probiotics in plaque reduction and gingival health maintenance among school children - A Randomized Control Trial. J Int Oral Health 2013; 5(5):33-7.

Ru (III) catalyzed oxidation of aliphatic ketones by N-bromosuccinimide in aqueous acetic acid: a kinetic study

Kinetics of Ru (III) catalyzed oxidation of aliphatic ketones such as acetone, ethyl methyl ketone, diethyl ketone, iso-butylmethyl ketone by N-bromosuccinimide in the presence of Hg(II) acetate have been studied in aqueous acid medium. The order of [N-bromosuccinimide] was found to be zero both in catalyzed as well as uncatalyzed reactions. However, the order of [ketone] changed from unity to a fractional one in the presence of Ru (III). On the basis of kinetic features, the probable mechanisms are discussed and individual rate parameters evaluated.

Groundwater quality and its suitability for domestic and agricultural use in Tondiar river basin, Tamil Nadu, India

Assessment of suitability of groundwater for domestic and agricultural purposes was carried out in Tondiar river basin, Tamil Nadu, India. The study area covers an area of 315 km(2) and lies in a semiarid region. Groundwater is the major source for domestic and agricultural activity in this area. Groundwater samples were collected from 45 wells during pre-monsoon and post-monsoon period in the year 2006. The water samples were analysed for physical and chemical characteristics. Suitability of groundwater for irrigation was evaluated based on salinity hazard, sodium percent, sodium adsorption ratio, residual sodium carbonate, US salinity diagram, Wilcox's diagram, Kelly's ratio and permeability index. Ca-HCO(3), mixed Ca-Mg-Cl and Na-Cl were the dominant groundwater types. High hardness and electrical conductivity in this area makes the groundwater unsuitable for drinking and agricultural purposes. Concentration of trace elements (Mn, Cu, Zn, Pb and Ni) did not exceed the permissible limit for drinking and agricultural purposes. Majority of the groundwater samples were unsuitable for domestic and agricultural purposes except for 31% and 36%, which were suitable for drinking and irrigation purposes, respectively.

Emergence of drug resistant mutations after single dose nevirapine exposure in HIV-1 infected pregnant women in south India

BACKGROUND & OBJECTIVES

Resistance to nevirapine (NVP) has been described with single dose preventive regimens in other populations. Our aim was to study the pattern and prevalence of HIV drug resistance (DR) at baseline (during pregnancy) and after delivery among antenatal women exposed to single dose NVP for prevention of parent to child transmission (PPTCT).

METHODS

HIV-infected, ART-naive primigravidae between 18-25 years of age, attending government antenatal clinics in Chennai, Vellore or Madurai were recruited. Drug resistance testing was carried out during pregnancy and after Sd-NVP treatment (one month after delivery) by Viroseq sequencing. HIV-1 testing by DNA PCR was done in newborns at 30 days.

RESULTS

Thirty one women were enrolled but only twenty six plasma specimens were analyzable (24 paired and two postnatal only). No major mutations were observed in any drug class at baseline though many polymorphisms were observed in both the reverse transcriptase and protease genes. Mutations to non-nucleoside reverse transcriptase inhibitors (NNRTI) were observed post-delivery in 33 per cent of women who were treated with Sd-NVP. None of the infants were HIV-positive.

INTERPRETATION & CONCLUSIONS

Among pregnant ART-naive women, baseline HIV drug resistance was not observed. A high rate of development of NNRTI class resistance among women treated with single-dose NVP was observed. Our results emphasize the need to implement more effective PPTCT regimens, minimizing emergence of drug resistance and thereby preserving long-term treatment options for HIV-infected women in India.

Hypohidrotic ectodermal dysplasia - diagnostic aids and a report of 5 cases

Hypohidrotic ectodermal dysplasia (HED) is a rare group of disorders affecting the hair, teeth, nails and sweat glands to a variable degree. There is a wide range of clinical presentation of HED. Missing teeth or abnormal tooth form may be the first indicator of the disorder. We present a case report of 5 cases of HED with their intraoral findings and their treatment plan. We also consider the various etiological factors and their clinical diagnostic aids.

Assessing the susceptibility of cruciferous Lepidoptera to Cry1Ba2 and Cry1Ca4 for future transgenic cruciferous vegetables

Advances in transgenic plants expressing Bacillus thuringiensis (Bt) insecticidal gene(s) offer a promising alternative to traditional insecticides for control of lepidopteran pests on important cruciferous vegetable crops such as cabbage and cauliflower. A public-private partnership, the Collaboration on Insect Management for Brassicas in Asia and Africa (CIMBAA), was formed in 2005 with the goal of developing dual-gene Bt cauliflower and cabbage, initially for India, to replace the use of broad spectrum, traditional insecticides. As a first step in this effort, the major lepidopteran pests of cruciferous vegetable crops [Plutella xylostella (L.), Pieris rapae (L.), Pieris brassicae (L.), Crocidolomia binotalis (L.), Hellula undalis (F.), Diacrisia obliqua Walker, Spodoptera litura F., and Helicoverpa armigera (Hübner)] were collected over a large geographic area (India, Indonesia, Taiwan, China, Australia, and the United States) and tested against purified Cry1Ba2 and Cry1Ca4 toxins, the toxins proposed to be expressed in the CIMBAA plants. Our results demonstrate that Cry1Ba2 and Cry1Ca4 were effective against the primary target of the CIMBAA plants, P. xylostella, regardless of geographic location, and had LC50 values <1.3 ppm. Furthermore, one or both toxins were effective against the other major pest Lepidoptera, except for S. litura or H. armigera which were less susceptible. No cross-resistance has been found between Cry1Ba2 and Cry1Ca4, suggesting cry1Ba2+cry1Ca4 cauliflower and cabbage could be an effective and sustainable tool to control, P. xylostella, the key lepidopteran pest on cruciferous vegetable crops, as well as most other Lepidoptera. As the CIMBAA plants are being developed, further tests are needed to determine whether they will express these proteins at sufficient levels to control all the Lepidoptera. Sustainable use of the dual-gene plants also is discussed.

Studies on the effect of plasticiser and addition of toluene diisocyanate at different temperatures in composite propellant formulations

Different composite propellant mixtures have been prepared using ammonium perchlorate, aluminium powder and hydroxyl terminated polybutadiene by varying the percentage of plasticiser and addition of toluene diisocyanate at different temperatures, and studied their different properties such as viscosity build-up, mechanical and ballistic properties and sensitivity. The data on different plasticiser level indicate that on decreasing the plasticiser content, there is a significant enhancement in end of mix viscosity, tensile strength and modulus while elongation decreases drastically. The data on sensitivity of the studied mixtures reveal that on decreasing the percentage of plasticiser, the sensitivity increases, accordingly. Further, the data on the effect of addition of TDI at different temperatures (35-60 degrees C) infer that on increasing the addition temperature of TDI there is a decrease in end of mix viscosity i.e. 800Pas at 35 degrees C to 448Pas at 60 degrees C. Moreover, there is no effect on mechanical and ballistic properties on higher temperature addition of TDI was observed.