Effect of cold atmospheric pressure plasma gas composition on the surface and cyto-compatible properties of low density polyethylene (LDPE) films

K. Navaneetha Pandiyaraj,A. Arun Kumar,M.C. RamKumar,K. Thirupugalmani,Avi Bendavid,Pi-Guey Su,S. Uday Kumar,P. Gopinath 한국물리학회 2016 Current Applied Physics Vol.16 No.7

In the present investigation, we have studied the influence of oxygen (O2) flow rate in the atmospheric pressure argon (Ar) plasma zone for improvement of the surface and cell compatible properties of LDPE film. Various characterization techniques such as contact angle (CA), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), etc were used to investigate the hydrophilicity, surface chemistry and morphology of LDPE films respectively. Fowke's approximation method was used to evaluate the polar and dispersion components of the total surface energy of LDPE films using contact angle values of three testing liquids. Moreover T-peel and lap shear tests were used to analyze the adhesive strength of the surface modified LDPE films. Finally cyto-compatibility of the surface modified LDPE film was analyzed by in vitro cell compatibility analysis which includes the cell viability and adhesion using NIH-3T3 fibroblast cells. The results obtained from various characterization techniques evidently revealed that cold atmospheric pressure (CAP) plasma treatment enhanced the surface properties (hydrophilicity, surface morphology and surface chemistry) of LDPE film. Owing to tailored physico-chemical changes induced by the CAP plasma treatment facilitates improvement in adhesive strength as well as adhesion and proliferation of cells on the surface of LDPE films.

The physical origins of transit time measurements for rapid, single cell mechanotyping

Nyberg, K.,Scott, M.,Bruce, S.,Gopinath, A.,Bikos, D.,Mason, T.,Kim, J.,Choi, H.,Rowat, A. GENERAL AND APPLIED CHEMISTRY JOURNALS 2016 LAB ON A CHIP Vol.16 No.17

<P>The mechanical phenotype or 'mechanotype' of cells is emerging as a potential biomarker for cell types ranging from pluripotent stem cells to cancer cells. Using a microfluidic device, cell mechanotype can be rapidly analyzed by measuring the time required for cells to deform as they flow through constricted channels. While cells typically exhibit deformation timescales, or transit times, on the order of milliseconds to tens of seconds, transit times can span several orders of magnitude and vary from day to day within a population of single cells; this makes it challenging to characterize different cell samples based on transit time data. Here we investigate how variability in transit time measurements depends on both experimental factors and heterogeneity in physical properties across a population of single cells. We find that simultaneous transit events that occur across neighboring constrictions can alter transit time, but only significantly when more than 65% of channels in the parallel array are occluded. Variability in transit time measurements is also affected by the age of the device following plasma treatment, which could be attributed to changes in channel surface properties. We additionally investigate the role of variability in cell physical properties. Transit time depends on cell size; by binning transit time data for cells of similar diameters, we reduce measurement variability by 20%. To gain further insight into the effects of cell-to-cell differences in physical properties, we fabricate a panel of gel particles and oil droplets with tunable mechanical properties. We demonstrate that particles with homogeneous composition exhibit a marked reduction in transit time variability, suggesting that the width of transit time distributions reflects the degree of heterogeneity in subcellular structure and mechanical properties within a cell population. Our results also provide fundamental insight into the physical underpinnings of transit measurements: transit time depends strongly on particle elastic modulus, and weakly on viscosity and surface tension. Based on our findings, we present a comprehensive methodology for designing, analyzing, and reducing variability in transit time measurements; this should facilitate broader implementation of transit experiments for rapid mechanical phenotyping in basic research and clinical settings.</P>

Changing Characteristics of Droughts over Kerala, India: Inter-Annual Variability and Trend

Abhilash S.,E. K. Krishnakumar,P. Vijaykumar,A. K. Sahai,B. Chakrapani,Girish Gopinath 한국기상학회 2019 Asia-Pacific Journal of Atmospheric Sciences Vol.55 No.1

Realized changes in the climate over Kerala received more attention during recent times under the back to back drought conditions prevailing over the state. The year 2016 registered as one of the worst and extreme drought year over Kerala in recent past. This extreme drought condition may be attributed to the combined effect of realized changes in the mean climate state as well as the climate variability.Both the recent and historic drought events over Kerala is examined and its possible impacts on different sectors like agriculture and water resource are studied using the standardized precipitation index (SPI). Historical occurrence of both the short term and long term water stress associated with deficit rainfall during monsoon and postmonsoon season is presented in the paper. It is found that south west monsoon rainfall over Kerala is decreasing over south Kerala during recent decades, whereas the post-monsoon rainfall is found to be increasing especially over south Kerala. There exists a weak relationship between Pacific SSTand Kerala rainfall. Trend analysis of SPI on different time scale showed negative trend and that negative trend increases with increasing time scale.

α-lipoic acid protects testis and epididymis against linuron-induced oxidative toxicity in adult rats

Prathima P.,Venkaiah K.,Daveedu T.,Pavani R.,Sukeerthi S.,Gopinath M.,Sainath Sri Bhashaym 한국독성학회 2020 Toxicological Research Vol.36 No.4

Linuron is well known for its antiandrogenic property. However, the effects of linuron on testicular and epididymal pro- and antioxidant status are not well defined. On the other hand, α-lipoic acid is well known as universal antioxidant. Therefore, the purpose of this study was twofold: firstly to investigate whether linuron exposure alters antioxidant status in the testis and epididymis of rats and if so, whether the supplementation of α-lipoic acid mitigates linuron-induced oxidative toxicity in rats. To address this question, α-lipoic acid at a dose of 70 mg/Kg body weight (three times a week) was administered to linuron exposed rats (10 or 50 mg/Kg body weight, every alternate day over a period of 60 days), and the selected reproductive endpoints were analyzed after 60 days. Respective controls were maintained in parallel. Linuron at selected doses reduced testicular daily sperm count, and epididymal sperm count, sperm motility, sperm viability, and number of tail coiled sperm, reduced activity levels of 3β- and 17β-hydroxysteroid dehydrogenases, decreased expression levels of StAR mRNA, inhibition of testosterone levels, and elevated levels of testicular cholesterol in rats over controls. Linuron intoxication deteriorated the structural integrity of testis and epididymis associated with reduced the reproductive performance over controls. Conversely, α-lipoic acid supplementation enhanced sperm quality and improved the testosterone synthesis pathway in linuron exposed rats over its respective control. Administration of α-lipoic acid restored inhibition of testicular and epididymal enzymatic (superoxide dismutase, catalase, glutathione reductase, glutathione peroxidise) and non-enzymatic (glutathione content), increased lipid peroxidation and protein carbonyl content produced by linuron in rats. α-lipoic acid supplementation inhibited the expression levels of testicular caspase-3 mRNA levels and also its activity in linuron treated rats. To summate, α-lipoic acid-induced protection of reproductive health in linuron treated rats could be attributed to its antioxidant, and steroidogenic properties.

CURRENT STATUS OF RATIO NUCLIDE SCINTIGRAPHY IN DETECTION OF S. O. Ls IN THE LIVER , A RETROSPECTIVE STUDY IN 5000 CASES

Samant, H. S.,Padhy, A. K.,Gopinath, P. G.,Basu, A. K. 대한핵의학회 1984 핵의학 분자영상 Vol.18 No.1

shimming with SAR reduction in high-field MRI

Son, H.W.,Cho, Y.K.,Gopinath, A.,Vaughan, J.T.,Lee, C.H.,Yoo, H. Informa UK (TaylorFrancis) 2013 Journal of electromagnetic waves and applications Vol.27 No.12

Analysis of Thermal Choking in Arbitrary Duct with Application to Dual-mode Ramjet Combustor

N. Ananthkrishnan,P. Tarey,Hyun Ko,K. Gopinath,K. Sreesankar 한국추진공학회 2016 한국추진공학회 학술대회논문집 Vol.2016 No.5

Thermal choking is an important phenomenon in ram and scram combustors. A zero-dimensional model is used to analyze Rayleigh flows in real-life combustors that feature volume heat addition due to combustion, area variation, wall heat loss and frictional losses, as well as different fuel injection rates and mixing efficiency. The method is used to analyze the occurrence of thermal choking in a model scramjet combustor and in a realistic dual-mode combustor geometry.

Architectural Model driven Dependability Analysis of Computer Based Safety System in Nuclear Power Plant

Amol Wakankar,Ashutosh Kabra,A.K. Bhattacharjee,Gopinath Karmakar 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.2

The most important non-functional requirements for dependability of any Embedded Real-Time SafetySystems are safety, availability and reliability requirements. System architecture plays the primary role inachieving these requirements. Compliance with these non-functional requirements should be ensuredearly in the development cycle with appropriate considerations during architectural design. In this paper,we present an application of system architecture modeling for quantitative assessment of systemdependability. We use probabilistic model checker (PRISM), for dependability analysis of the DTMCmodel derived from system architecture model. In general, the model checking techniques do not scalewell for analyzing large systems, because of prohibitively large state space. It limits the use of modelchecking techniques in analyzing the systems of practical interest. We propose abstraction basedcompositional analysis methodology to circumvent this limitation. The effectiveness of the proposedmethodology has been demonstrated using the case study involving the dependability analysis of safetysystem of a large Pressurized Water Reactor (PWR).

Effect of Measured Energy Restriction and Age Intervals on Growth, Nutrient Digestibility, Carcass Parameters, Bone Characteristics and Stress in Broiler Breeders during the Rearing Period

Sunder, G. Shyam,Kumar, Ch. Vijaya,Panda, A.K.,Gopinath, N.C.S.,Raju, M.V.L.N.,Rao, S.V. Rama,Reddy, M.R. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.7

This study aimed at targeting fixed increases in body weight (100 g/wk) by quantitatively regulating energy allowances (ME) in broiler breeders from 5 to 20 wks of age. Four energy regimes were tested: 1. The energy required for maintenance, activity and growth was calculated for 100 g increases in body weight/wk and a measured quantity of grower diet (160 g protein and 2,600 kcal ME/kg) was offered to the control group (ME-100) to achieve the anticipated weight gain. The energy allowances increased with age from 132 to 294 kcal/d. 2. Additionally, three energy regimes were considered, quantitatively reducing ME by 10% (ME-90) or 20% (ME-80) and increasing by10% (ME-110) over the control group. Each test group had 23 replicates5 female chicks housed in cages. The influence of energy regimes and age on growth, nutrient digestibility, carcass attributes, bone parameters and stress was evaluated at 4 wk intervals. Quantitative ME restriction by 10% (119-265 kcal/d) produced an average weight gain of 98.1 g/wk, which was closer to the targeted increase of 100 g/wk, whereas the control group attained it nine days earlier. Restriction of energy by 10 or 20% produced better conversion efficiency of feed, energy and protein and apparent digestibility of protein, Ca and P than 10% excess ME. Energy regimes did not influence eviscerated meat yield, but higher energy allowances (ME-110) significantly increased abdominal fat pad and liver weights and decreased giblet weight, percent muscle protein and tibia ash. Relatively higher stress was recorded in ME-restricted groups, as reflected by wider heterophil and lymphocyte ratios and increased bursa weight. Early age (5-12 wk) significantly influenced bone mineralization, conversion efficiency of feed, energy and protein and apparent digestibility of protein, Ca and P, while later ages (13-20 wk) increased eviscerated meat yield, abdominal fat, tibia weight and muscle protein and reduced stress. Energy regime x age interactions were significant and are discussed. In conclusion, the synthetic broiler line used in our study responded positively to controlled energy feeding during the rearing period. Breeders offered 119-265 kcal/d, a reduction of 10% energy over the control group, were more effective in regulating grower performance than the latter. In addition to energy regimes, age intervals also exhibited significant influence on specific parameters during the grower phase.

Restriction of Metabolizable Energy in Broiler Growers and Its Impact on Grower and Breeder Performance

Sunder, G. Skyam,Kumar, Ch. Vijaya,Panda, A.K.,Raju, M.V.L.N.,Rao, S.V. Rama,Gopinath, N.C.S.,Reddy, M.R. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.8

Metabolizable energy (ME) required for basal metabolism, activity and growth was considered as the criterion for targeting specific increases in body weight (100 g/week) of broiler chicks during the grower phase (5-20 weeks) and its impact was evaluated on breeder performance. Broiler female chicks (460) from a synthetic dam line were randomly distributed to 4 test groups with 23 replicates of 5 birds each and housed in cages. The first group (ME-100) was offered a calculated amount of ME by providing a measured quantity of grower diet (160 g protein and 2,600 kcal ME/kg) which increased with age and weight gain (133-294 kcal/bird/day). The other three groups were offered 10 or 20% less ME (ME-90 and ME-80, respectively) and 10% excess ME (ME-110) over the control group (ME-100). From 21 weeks of age, a single breeder diet (170 g protein and 2,600 kcal ME/kg) was uniformly fed to all groups and the impact of grower ME restriction on breeder performance evaluated up to 58 weeks. The targeted body weight gain of 1,600 g in a 16-week period was achieved by pullets of the ME-100 group almost one week earlier by gaining 8.7 g more weight per week. However, pullets in the ME-90 group gained 1,571 g during the same period, which was closer to the targeted weight. At 20 weeks of age, the conversion efficiency of feed (5.21-5.37), ME (13.9-14.1 kcal/g weight gain) and protein (0.847-0.871 g/g weight gain), eviscerated meat yield, giblet and tibia weights were not influenced by ME restriction, but the weights of abdominal fat and liver were higher with increased ME intake. Reduction of ME by 10% in the grower period significantly delayed sexual maturity (169.3 d), but increased egg production (152.5 /bird) with better persistency. Improved conversion efficiency of feed, ME and protein per g egg content were also observed in this group up to 56 weeks. The fertility and hatchability at 58 weeks of age were higher in the ME-90 group compared to the control and 10% excess ME feeding. In conclusion, the present study revealed the possibility of achieving targeted weight gain in broiler growers by feeding measured quantities of ME during the rearing period with consequential benefits in breeder performance.