Computerized Morphometric Analysis of Human Femoral Articular Cartilage

Objective. Articular cartilage shows changes with age that are considered to be the most important factors in the development and progression of osteoarthritis. The studies on age changes in articular cartilage have been traditionally based on individual observations but this approach is limited by its subjectivity and bias, yielding considerable variability. So the present study was conducted to observe various age related changes in morphology of femoral articular cartilage using computerized morphometric analysis. Design. The articular cartilage specimens were divided into two groups according to age: group 1 (n = 16) below 40 years (16–40 years) and group 2 (n = 12) above 40 years (41–86 years) of age. 5 μm thick paraffin sections were stained with H&E and analyzed using Image Pro Express image analysis software for quantitative analysis of articular cartilage. Various parameters, that is, total thickness of the cartilage, area of lacunae in each zone, area of subchondral cavities, and number of chondrocytes per 10,000 μm2 area in each zone were measured. Results. Significant difference with age was found in the total thickness and area of lacunae in zone 3. Conclusions. Not much difference is observed in articular cartilage morphology with age. So ageing is not the only risk factor in development of osteoarthritis

Examining Genetic and Environmental Influences on Alcohol use and Externalizing Behaviors in African American Adolescents

The aim of this thesis is to expand our understanding of the etiology of alcohol misuse and related disorders in African Americans using genetically informative study designs. Specifically, we take advantage of the candidate-gene approach and polygenic score analysis to extend the literature specific to African American populations. Chapter 2 explores gene x environment (GxE) interactions through the candidate gene approach to explore the relationship between two genes chosen on their potential relevance to stress response and adolescent alcohol use and misuse, among African American youth living in highly impoverished neighborhoods, as moderated by stressful life events. Chapter 3 implements polygenic score analyses to examine the effect of an aggregate of markers. We explore whether polygenic risk for alcohol dependence – derived from GWAS estimates in one discovery sample – predict alcohol use and broader externalizing behaviors and interact with stressful life events to predict alcohol use/misuse among high-risk African American youth

Optical Coefficients and PL Spectra with Variation in Ga-content in GaSeTe Thin Films: Visible Spectrum

The optical properties (transmission and emission) for Ga[x]Se[85 – x]Te[15](x = 0, 2, 6, 10, 15) semiconductor were studied using UV Visible spectra and PL Spectra of thermally evaporated thin films. Optical band gap is found to be decreasing with increased Ga-content in the compositions. Increase in refractive index, dielectric constants and absorption coefficient is observed in the wavelength region 550-850 nm.The fall in the optical band gap is explained with chemical bond approach and electro negativity. The increase in refractive index (n) is interpreted in association to the mean coordination number and cohesive energy. Direct band gap is found to be allowed in these thin films

An anatomical study of pterygoalar bar and its clinical relevance

Objectives: Pterygoalar ligament extends from the root of lateral pterygoid plate to the under surface of greater wing of sphenoid. The ligament may ossify partly or completely leading to the formation of bony bar. Complete or incomplete pterygoalar bar may act as an obstacle for approaching retro-and para-paharyngeal spaces for various surgical procedures. Methods: A total of 55 dried adult skulls and 20 sphenoid bones were observed for the presence of complete or incomplete ossification of the pterygoalar ligament. Results: Totally, 17 bones (22.67%) showed partial ossification of the pterygoalar ligament. Complete ossification was not observed in any of the cases. Bilateral incomplete pterygoalar bar was seen in six skulls. Unilateral incomplete pterygoalar bar was seen in 11 cases (5 left and 6 right sides). Conclusions: Knowledge of complete or partial ossification of the various ligaments in the region is important for anesthetists, surgeons and dentists. Being closely related to foramen ovale, such ossified bars of bone may cause entrapment neuropathy of mandibular nerve and its branches

A Study of Changes in Morphology of Osteoarthritic Articular Cartilage Using Computerized Image Analysis

Histological studies on articular cartilage have been traditionally based on individual observations but this approach is limited by its subjectivity and bias, yielding considerable variability. So the present study was conducted to observe the various changes in the morphology of osteoarthritic femoral articular cartilage using computerized image analysis. The cartilage specimens were divided into two groups: group 1 (n=23) (46–81 years) consisted of OA specimens. Group 2 (n=12) (41–86 years) consisted of non-OA specimens. A 5 μm thick paraffin sections were stained with H&E staining and analyzed using Image-Pro Express image analysis software for quantitative analysis of articular cartilage. Various parameters, namely, total thickness of the cartilage, area of lacunae in each zone, area of subchondral cavities, and number of chondrocytes per 10,000 μm2 area in each zone, were measured. Microscopic appearance of OA cartilage was much different as compared to control. Various changes seen were different in all specimens and they were not related to age. Lacunar size in all four zones was found to differ significantly in the OA (group 1) and control (group 2) (P<0.05). The results suggest that OA should be considered as a specific process and not simply as an inevitable feature of ageing

Revolutionize Efficiency of Solar PV Modules by using Nanotechnology

Nanoscale technology may be the mantra that will unlock the secret to major advancements that would fulfill the need for clean and renewable sources of energy. Find out more about this path-breaking discovery. Clean power generation from renewable energy is seen as the solution to the climate impacts of the energy sector. However, there are barriers yet to be overcome to scale up energy production through renewable. The conversion efficiency of a solar cell is the percentage of the solar energy shining on a PV device that is converted into electrical energy. Improving conversion efficiency is a key goal of much research and help to make PV technologies cost competitive with more traditional source of energy. A novel structure of photovoltaic cell design is demonstrated theoretically in this study which can improve conversion efficiency drastically and can reduce size of module too. This structure of cell can capture sunlight from all direction except bottom surface. The architecture is different from that of conventional PV cells which is like plates in which top surface receives sunlight. This new three dimensional cells resembles a tiny tower and several such towers can be staked like a high rise building. Fabrication of the cells begins with a silicon wafer, which can also serve as the solar cell’s bottom junction. The advantages of nanotubes over metallic grids are dimension reduction thus reduced loss owing to shading, nanotubes provide one dimensional conduction, and nanotubes can be impregnated subsurface eliminating shading loss completely and also capturing charges which are unable to reach to surface The main challenges now for the application of nanomaterials in the energy sector are the improvement of efficiency, reliability, safety and lifetime, as well as the reduction of costs. To date, universities, research institutes, and even governments are paying attention to the synergy that could be established between nanotechnology and renewable energy. In Singapore, the Institute for Bioengineering and Nanotechnology was created to work closely on the field.Recently, the institute has developed a more efficient and longer lasting fuel cell through a compound of gold, copper and platinum nanoparticles. The researchers found out that replacing the innermost part of the catalyst of the fuel cell with gold and copper alloy, while leaving just the outer layer in platinum, will deliver five times higher activity. Platinum nanoparticles are often used as catalyst in commercially available fuel cells, since platinum is the only metal that is resistant to extreme acidic condition inside such a cell. The prevalent use of fuel cells has been deterred by the high cost of platinum and its low stability. The new advanced fuel cell material could help overcome these barriers, providing a less expensive material and much greater stability. In 2011, the US President Barack Obama launched the Advanced Manufacturing Partnership, a national effort by the industry, universities, and the federal government that provides more than $500 million in investments in emerging technologies such as information technology, biotechnology, and nanotechnology. To conclude, nanoscale technology looks promising as a major contributor to advancements needed to fulfill the potential of emerging sources of clean, renewable energy. Progress in the comparatively new area of nanoelectronics in particular could be the basis for new manufacturing processes and devices to make renewable energy systems and technologies more efficient and cost-effective