Cyclic olefin copolymer based microfluidic devices for biochip applications: Ultraviolet surface grafting using 2-methacryloyloxyethyl phosphorylcholine

This report studies the surface modification of cyclic olefin copolymer (COC) by 2-methacryloyloxyethyl phosphorylcholine (MPC) monomer using photografting technique for the purpose of biointerface applications, which demonstrate resistance to both protein adsorption and cell adhesion in COC-based microfluidic devices. This is essential because the hydrophobic nature of COC can lead to adsorption of specific compounds from biological fluids in the microchannel, which can affect the results during fluidic analysis and cause clogging inside the microchannel. A correlation was found between the irradiation time and hydrophobicity of the modified substrate. Static water contact angle results show that the hydrophilicity property of the MPC-grafted substrate improves with increasing irradiation time. The contact angle of the modified surface decreased to 20 ± 5° from 88 ± 3° for the untreated substrate. The surface characterization of the modified surface was evaluated using x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR spectroscopy). Attenuated total reflection-FTIR and XPS results show the presence of the phosphate group (P-O) on modified COC substrates, indicating that the hydrophilic MPC monomer has successfully grafted on COC. Finally, it was demonstrated that cell adhesion and protein adsorption on the MPC modified COC specimen has reduced significantly.     

Investigation on CO(2) laser irradiation inducing glass strip peeling for microchannel formation

The study investigates the use of CO₂ laser to induce glass strip peeling off to form microchannels on soda lime gass substrate. The strip peeling exhibits a strong dependence on the energy deposition rate on the glass surface. In spite of the vast difference in the combination of laser power and scanning speed, when the ratio of the two makes the energy deposition rate in the range 3.0-6.0 J/(cm² s), the temperature rising inside glass will be above the strain point and reach the softening region of the glass. As a result, glass strip peeling is able to occur and form microchannels with dimensions of 20-40 μm in depth and 200-280 μm in width on the glass surface. Beyond this range, higher energy depsotion rate would lead to surface melting associated with solidification cracks and lower energy deposition rate causes the generation of fragment cracks.     

Incidence and risk for traumatic and overuse injuries in top-level road cyclists

All traumatic and overuse injuries occurring during an average period of 4 years (2002/09) in a group of 51 currently active road top-level cyclists were retrospectively registered through clinical interviews. Average age was 25.8 years. Average training and competition period was 28.3 ± 2.4 h a week. Only 8 cyclists (15.6%) were completely free from lesions during the period of study. The remaining 43 cyclists suffered a total of 112 lesions; however, 9 out of these were unrelated to their cycling practice. These 103 cycling-related injuries include 50 (48.5%) traumatic and 53 (51.5%) overuse injuries. Twenty-eight fractures were reported, the clavicle being the most frequently affected bone (11 cases). The 68.5% of overuse injuries were located in the lower limbs. Most overuse injuries (89.6%) occurred during the training period. According to the injury abbreviated scale (AIS), severe lesions were only found in 4 cases (8% of traumatic injuries). Overall injury rates were 0.50 per racer/year, 2.02 per studied racer, and 0.007 per 1000 km of training and competition. Active professional top-level cyclists are exposed to a high injury risk. According to the scarce previously published data the current study provides relevant information on the injury occurrence of still active top-level road cycling.     

African American preschool children's physical activity levels in Head Start

The purpose of this study was to describe the physical activity levels of urban inner city preschoolers while attending Head Start, the federally funded preschool program for children from low-income families. Participants were 158 African American children. Their physical activity during Head Start days was measured using programmed RT-3 accelerometers. Results revealed that the children spent the most time in sedentary and light physical activity, while their participation in moderate-to-vigorous physical activities was low. Given the sedentary class format and limited physical space for the Head Start programs observed, we suggest adding a structured physical activity component to Head Start schools to fight the overweight and obesity crisis.     

Design and performance analysis of PID controller for an automatic voltage regulator system using simplified particle swarm optimization

This paper presents the design and performance analysis of Proportional Integral Derivate (PID) controller for an Automatic Voltage Regulator (AVR) system using recently proposed simplified Particle Swarm Optimization (PSO) also called Many Optimizing Liaisons (MOL) algorithm. MOL simplifies the original PSO by randomly choosing the particle to update, instead of iterating over the entire swarm thus eliminating the particles best known position and making it easier to tune the behavioral parameters. The design problem of the proposed PID controller is formulated as an optimization problem and MOL algorithm is employed to search for the optimal controller parameters. For the performance analysis, different analysis methods such as transient response analysis, root locus analysis and bode analysis are performed. The superiority of the proposed approach is shown by comparing the results with some recently published modern heuristic optimization algorithms such as Artificial Bee Colony (ABC) algorithm, Particle Swarm Optimization (PSO) algorithm and Differential Evolution (DE) algorithm. Further, robustness analysis of the AVR system tuned by MOL algorithm is performed by varying the time constants of amplifier, exciter, generator and sensor in the range of ?50% to +50% in steps of 25%. The analysis results reveal that the proposed MOL based PID controller for the AVR system performs better than the other similar recently reported population based optimization algorithms.     

Study of C-Reactive Protein and Myocardial Infarction in the Indian Population

To analyse the association of high sensitivity C-reactive (hsCRP) protein levels and −717A/G single nucleotide polymorphism of CRP with acute myocardial infarction (AMI) in the Indian population. Study population included 100 MI cases wherein 32 patients had experienced previous MI (MI-Group-1), 68 MI cases were recruited at presentation (MI-Group-2) and equal number of age and gender matched healthy individuals. hsCRP levels were determined by ELISA and genotyping of −717A/G was carried out by polymerase chain reaction-based restriction digestion method. The −717A/G genotypes did not influence hsCRP level and their distribution did not differ between groups. However, in the present study hsCRP demonstrated significant correlation with BMI in controls of both the genders and with triglycerides in females of AMI at presentation who otherwise are with low risk profile. Identifying traditional risk factors associated with inflammation may help in controlling the acute event.     

Antarctic Harsh Environment as Natural Stress Model: Impact on Salivary Immunoglobulins, Transforming Growth Factor-β and Cortisol Level

The Antarctic continent on the planet Earth is full of environmental extremes. It is considered as natural stress model. Therefore, the present study examined the effect of harsh environment on the certain salivary markers of 28th Indian Antarctic expeditioners. Thirty healthy men and women (median age 36 year; range 22–61 year) participated in this study. Parameters measured were salivary IgA (SIgA), IgM (SIgM), TGF-β and cortisol level at three different time points: (I) before leaving India on 26th October 2008 for base line level; (II) after 1 month on-board journey on 31st January 2009 in Southern Ocean and (III) after 1 month staying at Maitri, Antarctica on 3rd March 2009. Our observation indicated that Ship borne journey and Antarctic environment increased the SIgA levels while that of SIgM level was not altered on-board but decreased by staying for 1 month at Antarctica. No significant alteration was found in the TGF-β and cortisol level at any point of time. The present study concluded that ship borne journey and Antarctic environment may induce the SIgA level while SIgM level decreased in environmental extremes of Antarctica.     

Evaluation of Luteolin in the Prevention of N-nitrosodiethylamine-induced Hepatocellular Carcinoma Using Animal Model System

Hepatocellular carcinoma (HCC) is one of the commonest tumors worldwide. The treatment of HCC is vital for disease diagnosis and prognosis, as the liver is the most important organ controlling metabolic functions. Now-a-days, western folklore medicines are largely dependent on the phyto compounds which are highly effective in therapy and with low side effects. Luteolin is a flavonoid (3,4,5,7-Tetrahydro flavones) possess anti-inflammatory, anticancer and anti allergic property. The present study evaluates the efficacy of luteolin against N-nitrosodiethylamine (DEN) induced HCC in albino rats. In the highlight of the above, luteolin was evaluated for its efficacy against DEN induced HCC in male Wistar albino rats. The Biochemical parameters such as tissue damaging enzymes viz., AST, ALP, LDH and γ-GT, enzymatic antioxidants viz., SOD, CAT, GSH and GPx and histopathological changes have been estimated. The tissue damaging enzymes were found to be high in DEN alone treated group whereas the enzymatic antioxidants decreased destructively. Severe lesions and cirrhosis were observed in the toxin (DEN alone) treated group. The luteolin treated DEN group altered the tissue damaging enzymes and the enzymatic antioxidants. The damaged lesion in the histoarchitecture of DEN treated rat liver was almost completely restored. Finally this study strongly demonstrates that luteolin has potent curative property against HCC in albino rats.