Role of Surface Chemistry of Ta Metal Foil on the Growth of GaN Nanorods by Laser Molecular Beam Epitaxy and Their Field Emission Characteristics.

This study investigates the influence of surface nitridation of Ta metal foil substrates on the growth of GaN nanorods using the laser molecular beam epitaxy (LMBE) technique and the field emission characteristics of the grown GaN nanorod ensemble. Surface morphology examinations underscore the pivotal role of Ta foil nitridation in shaping the dimensions and densities of GaN nanorods. Bare Ta foil fosters the formation of high-density, vertically self-aligned GaN nanorods at a growth temperature of 700 °C. Furthermore, the density of these nanorods is directly related to the duration of Ta foil nitridation, with increased duration leading to a reduced nanorod density. X-ray Photoelectron Spectroscopy (XPS) studies reveal that the transition of the Ta foil surface from tantalum oxide to tantalum nitride during nitridation emerges as a crucial factor influencing GaN nanorod growth. Photoluminescence (PL) spectroscopy at ambient temperature reveals a strong near-band-edge (NBE) emission peak with negligible defect-related peaks, displaying the high optical quality of the GaN nanorods. The highly dense vertically aligned GaN nanorod ensemble growth without Ta prenitridation exhibits the most favorable field emission performance, featuring a turn-on field of 2.1 V/µm, a field enhancement factor of 2480, and a stable long-term operation at the emission current density of 2.26 mA/cm2. This study advances the understanding of the role of the surface chemistry of metal foil in determining GaN nanorod growth and opens up exciting possibilities for tailoring advanced optoelectronic devices for specific application requirements.

Treatment of Human Intraosseous Periodontal Defects Using Recombinant Human Bone Morphogenetic Protein-2: A Randomized Controlled Clinical Trial.

Aim The purpose of this research was to assess the clinical and radiographic outcomes of recombinant human bone morphogenetic protein-2 (rhBMP-2) for the treatment of intraosseous abnormalities after periodontal flap surgery. Material and methods Patients aged 35-55 years who had undergone periodontal treatment at Shree Bankey Bihari Dental College and Research Centre, Ghaziabad, and had a total of 14 intraosseous abnormalities were included in the research. Those in the control group had open flap debridement with alloplast, whereas those in the experimental group underwent the same procedure with the addition of rhBMP-2. Clinical indicators, such as plaque index (PI), gingival index, probing pocket depth (PPD), clinical attachment level, and radiographic defect fill, were collected at baseline at three months, six months, and nine months. Results The findings demonstrated that following periodontal treatment, both sets of patients had considerable improvements in their PI, gingival index, and PPD. The degree of relative connection improved significantly in both groups. When comparing the two groups radiographically, we saw that the test group had significantly better defect fill than the control group. Conclusion According to this research, there was a statistically significant decrease in PI, gingival index, PPD, clinical attachment level, and radiographic bone fill in patients who received rhBMP-2. Open flap debridement with rhBMP-2 and alloplastic bone grafts showed better reduction than open flap debridement with alloplastic bone grafts group in the radiographic defect fill.

Gingival Augmentation in the Thin Phenotype Using Injectable Platelet-Rich Fibrin and Microneedling.

Objective This study set out to examine the results of microneedling (MN) with and without injectable platelet-rich fibrin (i-PRF) in treating individuals with thin periodontal phenotypes, specifically focusing on the effects on gingival thickness (GT) and keratinized tissue width (KTW). Materials and methods This was a split-mouth study involving 32 healthy patients with 64 sites having thin phenotypes classified into two groups. On the one side, i-PRF was injected (Group A), while on the other side (Group B), MN along with i-PRF was used at intervals of 10 days for a month. GT and KTW were measured at baseline, three months, and six months. The parameters were compared intra and intergroup-wise at baseline, three months, and six months using the IBM SPSS Statistics software version 24 (IBM Corp., Armonk, NY) and the chi-square test. Results The findings revealed that when comparing Group A, which received just i-PRF, to Group B, which had i-PRF in conjunction with MN, there was a statistically significant increase in GT in Group B. Conclusions This is a novel method in that it does not need surgical innervations to expand the gingiva in breadth or thickness. Although MN's neoangiogenesis impact contributed to thicker gingiva, i-PRF showed a greater capacity for the release of several growth factors.

A comparison of the efficacy of scaling and root planning with application of pomegranate chip, pomegranate gel, and scaling and root planing in sufferers with adult periodontitis - A prospective study.

CONTEXT: The use of herbal compounds is a comparatively safer alternative to synthetic compounds for periodontal therapy. AIM: This study aims to investigate effect of extracts from pomegranate in a chip and gel form on periodontitis following scaling and root planing in adult periodontitis patients. SETTINGS AND DESIGN: An in vivo prospective study. MATERIALS AND METHODS: Thirty patients of adult periodontitis with initial pocket depth ≥4 mm were enrolled into the research and divided randomly into three groups, (10 in every group). After baseline examination, scaling root planing of tooth was achieved. Then subgingival application of medicated chips in Group 1, gel in Group 2, and placebo in Group 3 was done. Plaque index, gingival index, probing pocket depth, and relative attachment ranges were recorded at baseline, 21 days and 45 days. STATISTICAL ANALYSIS USED: Analysis of variance test. RESULTS: The study confirmed significant improvements of plaque index ratings in Group 1 at day 21. It showed significant improvements of gingival index scores, probing pocket depth, and clinical attachment at day 21 and 45. Gingival index rankings and probing pocket depth were extensively elevated altogether in three groups at day 21 and 45. Relative attachment degree was extensively raised in Group 1 and Group 2 at day 21 and day 45 and in Group 3 at day 45. The relative attachment degrees confirmed significance at day 21 between Group 1 and Group 2, and Group 1 and Group 3. CONCLUSION: Pomegranate extracts in chip and gel shape may offer additionally advantages to scaling and root planing for remedy of periodontal pockets.

Self-Induced Growth of GaN Nanowall Structure on Si (111) by Laser Molecular Beam Epitaxy.

Evolution of GaN nanostructure grown on Si (111) substrate has been studied systematically using laser molecular beam epitaxial process. The in-situ reflection high energy electron diffraction and ex-situ high resolution X-ray diffraction studies reveal that the GaN nanostructures have a hexagonal-wurtzite phase and grow along c-axis. The GaN morphology changes from compact granular layer to faceted pyramids to nanowall structure as a function of laser ablation frequency of the KrF excimer laser and radio frequency nitrogen plasma condition. It is observed that GaN nanowall structure is formed on Si (111) when grown under strong nitrogen-rich flux at a higher growth rate and growth temperature. The crystalline and optical quality of the GaN nanostructures significantly improved with increase of laser ablation frequency. The nanowall structure shows good optical emission properties with an intense, sharp near-band edge emission and a negligible deep band luminescence.

Evaluation of the Protection Provided by Hepatitis B Vaccination in India.

OBJECTIVE: In India, Hepatitis B vaccination is recommended at 6 wk except for hospital-deliveries. The authors examined protection afforded by the birth dose. METHODS: A case-control study was done. HBsAg and HBcAb were tested in 2671 children, 1 to 5 y and HBsAb was evaluated in a subset of 1413 children. Vaccination history was recorded. Cases were HBsAg carriers. In another analysis, children who got infected (HBsAg and/or HBcAb positive) were considered as cases. Exposed were the unvaccinated. In another analysis, exposed were those vaccinated without the birth dose. RESULTS: The odds ratio (OR) for HBsAg positivity with birth vaccination was 0.35 (95% CI 0.19-0.66); while with vaccination at 6 wk was 0.29 (95%CI 0.14-0.61), both compared to unvaccinated. Birth vaccination has no added protection when compared to the unvaccinated. Unvaccinated children in index study had HBsAg positivity of 4.38%. The number needed to treat (NNT) to prevent one case of HBsAg positivity was 32.6 (95% CI, 20.9 to 73.6). The odds of getting HBV infection was 0.42 (CI 0.25-0.68) with birth dose and 0.49 (CI 0.30-0.82) without the birth dose compared to the unvaccinated. Protective antibody (HBsAb) was present in about 70% of the vaccinated. In the unimmunised, in the first 2 y HBsAb protection was present in 40%. The odds ratio (OR) for HBsAb in the fully vaccinated between 4 and 5 y was 1.4 (95%CI 0.9-2.18) compared to the unvaccinated. CONCLUSIONS: The present study lends support to the pragmatic approach of the Government to vaccinate babies born at home starting at 6 wk.

Translocation across a self-healing block copolymer membrane.

Herein, a membrane prepared from the self-assembly of poly(styrene-co-acrylonitrile)-b-poly(ethylene oxide)-b-poly(styrene-co-acrylonitrile) micelles is found to exhibit translocation of nano-objects dispersed in aqueous solution. With the water flow as a driving force, temporary pores are created in between the micelles to facilitate the passage of nano-objects. These temporary pores close afterwards through a self-healing mechanism. As main results, polystyrene and silica nanoparticles exhibited a selective translocation directly influenced by their size and applied pressure.

Intra-gastric pressures in neonates receiving bubble CPAP.

OBJECTIVE: To study intra-gastric pressures in neonates receiving bubble continuous positive airway pressure (BCPAP) by nasopharyngeal prong. METHODS: Twenty seven neonates were recruited for the study. BCPAP pressure of 6 cm water was used in all the neonates. A pressure sensor attached to orogastric tube, measured the intra-gastric pressure prior to starting BCPAP and again between 30 and 90 min of BCPAP. The clinical variables like Downe's score, oxygen saturation, venous blood gas pH, pCO(2) and abdominal girth were recorded alongside with pressure readings. RESULTS: BCPAP resulted in improvement (p < 0.05) in parameters of respiratory distress such as Downe's score (DS), oxygen saturation (SpO(2)) and venous blood gas parameters (pH, pCO(2)). There was no statistical significant increase in intra-gastric pressures (p = 0.834). There were no gastrointestinal complications; abdominal distention, necrotising enterocolitis or gastric perforation during the study. CONCLUSIONS: Nasopharyngeal BCPAP at 6 cm of water pressure is an effective modality of treating babies with respiratory distress and the present study shows that it is not associated with a significant rise in intra-gastric pressures.

Association of birth of girls with postnatal depression and exclusive breastfeeding: an observational study.

OBJECTIVES AND HYPOTHESIS: To examine the influence of gender of the baby on exclusive breastfeeding and incidence of postnatal depression (PND). We hypothesise that in a society with a male gender bias there may be more PND and less exclusive breastfeeding of the girl child. DESIGN: Prospective study. SETTING: The study was conducted in an urban, tertiary hospital in Delhi. PARTICIPANTS: Mothers delivering normally with their babies roomed-in.1537 eligible women participated in the study. PRIMARY AND SECONDARY OUTCOME MEASURES: Exclusive breastfeeding within the first 48 h of life and score on the Edinburgh Postnatal Depression Scale (EPDS) were recorded. RESULTS: 3466 babies were born in the hospital. There were 792 girls for every 1000 boys. Among primiparous women, the sex ratio was 901 girls per 1000 boys. For second babies, the sex ratio was 737:1000. If the first child was a girl the birth ratio fell to 632. 1026 mothers were exclusively breastfeeding. Exclusive breastfeeding of boys was significantly higher (70.8% vs 61.5%, p<0.001). The EPDS score was significantly higher with the birth of girls (EPDS 6.0±3.39 vs 5.4±2.87, p<0.01). Women with an EPDS score >11 were less likely to exclusively breastfeed (p<0.01). CONCLUSIONS: The results point to a pro-male gender bias evidenced by a low sex ratio at birth, higher EPDS score in mothers of girls and less breastfeeding of female children.

Reversible 2D/3D coatings from zipper-assembly of block copolymer micelles.

A zipper-assembly of micelles into 2D/3D coatings is reported. Block copolymer micelles that incorporate a poly(n-octadecyl methacrylate) block are zipped and unzipped on demand onto a PMMA surface. The mechanism implies an interdigitation of molecular brushes enabling 15 nm micelles to be assembled into monolayers or multilayers.

Dynamic interactive membranes with pressure-driven tunable porosity and self-healing ability.

When pressure is applied to dynamic interactive membranes consisting of micelles composed of a triblock copolymer, their morphologies can be fine-tuned. Membranes with a range of porosities are accessible which can regulate and thereby control filtration performance and also display effective autonomous healing.

Clinical efficacy of subgingivally delivered 0.5% controlled release azithromycin gel in the management of chronic periodontitis.

BACKGROUND: Recent developments suggest that the local delivery of antimicrobials into periodontal pockets can improve periodontal health. Azithromycin (AZM) has a wide antimicrobial spectrum of action toward anaerobic bacteria as well as Gram-negative bacilli. It is effective against periodontal pathogens such as Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Therefore, this study was undertaken to investigate the clinical effectiveness of AZM at 0.5% concentration in an indigenously prepared bioabsorbable controlled release gel as an adjunct to non-surgical mechanical therapy in the treatment of chronic periodontitis. MATERIALS AND METHODS: Thirty sites in patients with chronic periodontitis and probing depth (PD) 4-6 mm were categorized randomly into two treatment groups: Scaling and root planing (SRP) plus 0.5% AZM gel (group 1) and SRP only (group 2). Clinical evaluation was undertaken using the Gingival Index (GI) of Loe and Silness and plaque was assessed using the Turesky et al. modification of Quigley Hein Index at baseline and 21 days. Pocket PD and clinical attachment level (CAL) were also measured. STATISTICAL ANALYSIS: Results were expressed as mean±standard deviation and percentages and the data were analyzed using Statistical Package for Social Sciences (SPSS version 16.0, SPSS, Chicago, IL) software. RESULT: Both therapies resulted in significant improvements. Mean reduction in GI from baseline to 21 days was 1.20±0.41 and 0.73±0.45 in group 1 and group 2, respectively. Plaque Index also improved through the study period in both groups, i.e., 0.86±0.51 in group 1 and 1.6±0.97 in group 2. Mean PD reduced significantly with SRP plus AZM gel application in group 1, i.e., 2.1±0.91 mm as compared to 1.0±1.06 mm achieved with SRP alone. A significant gain in mean CAL gain was observed in the test group (1.8±0.63 mm) as compared to control group (1.0±1.06 mm). CONCLUSION: Although both treatment strategies seem to benefit patients, the adjunctive use of 0.5% of AZM showed significant results.

Prospective exploration of synthetically feasible, medicinally relevant chemical space.

We describe a novel approach to direct the exploration of chemical space in an effort to balance synthetic accessibility and medicinal relevancy prior to experimental work. Reaction transforms containing empirical reactivity and compatibility information are dynamically assembled into reaction sequences (vProtocols) utilizing commercially available starting material feedstock. These vProtocols are evolved and optimized by a genetic algorithm, which leverages fitness functions based on predicted properties of generated molecular products. We present the underlying concepts, methodology and initial results of this prospective approach.

A simple and readily integratable approach to toxicity prediction.

A simple, highly extensible computational strategy to assess compound toxicity has been developed with the premise that a compound's toxicity can be gauged from the toxicities of structurally similar compounds. Using a reference set of 13645 compounds with reported acute toxicity endpoint dose data (oral, rat-LD(50) data normalized in mg/kg), a generic utility which assigns a compound the average toxicity of structurally similar compounds is shown to correlate well with reported values. In a leave-one-out simulation using the requirement that at least one structurally similar member in a "voting consortium" is present within a reference set, the strategy demonstrates a predictive correlation (q wedge 2) of 0.82 with 57.3% of the compounds being predicted. Similar leave-one-out simulations on a set of 1781 drugs demonstrate a q wedge 2 of 0.74 with 51.8% of the compounds being predicted. Simulations to optimize similarity cutoff definitions, consortium member size, and reference set size illustrate that a significant improvement in the quality and quantity of predictions can be obtained by increasing the reference set size. Similar application of the strategy to subchronic and chronic toxicity data should be possible given reasonably sized reference sets.