Effect of Mechanical Alloying and Sintering Environment on the Crystallographic Evolution, Microstructure, Mechanical and Corrosion Properties of Porous Ti4Al4Co Alloy

Pradeep Singh,Vikas Shrivastava,I. B. Singh,D. P. Mondal 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

Three group of porous Ti4Al4Co samples made of (i) unmilled powder and vacuum sintered (S1), (ii) milled powder andvacuum sintered (S2), and (iii) milled powder sintered in open atmosphere (S3) were prepared. Phase change, crystallite sizeand lattice strain variations due to powder milling and sintering were examined by SEM and XRD. To evaluate mechanicalproperty, alloy samples were subjected to the uniaxial compression test. For corrosion analysis, Tafel plot was plotted usingelectrochemical corrosion system in simulated body fluid (SBF) as electrolytic medium. From the obtained results, it wasfound that significant microstructural transformation takes place due to milling and change in sintering atmosphere. SampleS1possessed 139 MPa compressive strength, which was about 48% and 76% higher than samples S2and S3respectively. Corrosion current density for S3was found as 5.5 ± 0.3 μA/cm2 which is 7 and 12 times lower than S2and S1samples.

Spermidine restores dysregulated autophagy and polyamine synthesis in aged and osteoarthritic chondrocytes via EP300: response to correspondence by Borzì et al.

Pradeep K. Sacitharan,George Bou Gharios,James R. Edwards 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Hesperidin a flavanoglycone protects against γ-irradiation induced hepatocellular damage and oxidative stress in Sprague-Dawley rats

Pradeep, K.,Park, S.H.,Ko, K.C. North-Holland ; Elsevier Science Ltd 2008 european journal of pharmacology Vol.587 No.1

Oxidative stress plays a pivotal role in the pathogenesis and progression of γ-irradiation induced cellular damage and the administration of dietary antioxidants has been suggested to protect against the subsequent tissue damage. Here, we present the data to explore the hepatoprotective and antioxidant effect of hesperidin, a naturally occurring citrus flavanoglycone, against γ-irradiation induced oxidative damage in the liver of rats. Healthy male Sprague-Dawley rats were exposed to γ-irradiation (1 Gy, 3 Gy and 5 Gy) and were administered hesperidin (50 mg/kg and 100 mg/kg, b.w, orally) for 7 days post irradiation. The changes in body weight, liver weight, spleen index, serum and liver aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), γ-glutamyl transpeptidase (γ-GT) and serum ceruloplasmin levels were determined along with differences in the liver histopathology. Liver thiobarbuturic acid reactive substance as an index for lipid peroxidation and the levels of enzymatic antioxidants like superoxide dismutase, catalase, glutathione peroxidase and the status of non-enzymatic antioxidants as an index for oxidative stress were also determined. Exposure to γ-irradiation resulted in hepatocellular damage in a dose-dependent manner, featuring a significantly decreased body weight and liver weight and higher levels of serum AST, ALT, ALP, LDH and γ-GT levels and a simultaneous decrease in their levels in the liver tissue. Oxidative stress was evidenced by elevated levels of lipid peroxidation and a decrease in the levels of key enzymatic and non-enzymatic antioxidants in the liver. However, the γ-irradiation induced toxic effects were dramatically and dose-dependently inhibited by hesperidin treatment as observed by the restoration in the altered levels of the marker enzymes, lipid peroxidation, enzymatic and non-enzymatic antioxidants. The results of the biochemical observations were supported by the histopathological findings. Thus, oral administration of hesperidin was found to offer protection against γ-irradiation induced hepatocellular damage and oxidative stress in rats, probably by exerting a protective effect against hepatocellular necrosis via its free radical scavenging and membrane stabilizing ability.

Pulsed electric field (PEF) technology for microbial inactivation in low-alcohol red winePulsed electric field (PEF) technology for microbial inactivation in low-alcohol red wine

Pradeep Puligundla,변유량,목철균 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.6

The decontamination of spoilage-related microbes in low-alcohol red wine was performed using a serial multiple electrode pulsed electric field (PEF) treatment system. The system consisted of seven electrodes connected in series, and it has been designed to produce square-wave high-voltage pulses of 1 ls duration at various electric field strengths and frequencies for decontamination. The initial counts of aerobic bacteria, yeast and lactic acid bacteria (spoilage-associated microbes) in the wine were 5.56, 5.61 and 5.22 log CFU/mL, respectively. The pattern of decontamination of the spoilage microorganisms followed first-order kinetics and the decontamination effect increased as the field strength and frequency increases. DHz and DPEF values were inversely related to the electric field strength of the PEF treatment. The yeast exhibited relatively low DPEF-value than the aerobic and lactic acid bacteria. The lowest ZPEF-value was observed for the lactic acid bacteria (24.6 kV/cm) among the spoilage microbes.

Spermidine restores dysregulated autophagy and polyamine synthesis in aged and osteoarthritic chondrocytes via EP300

Pradeep K. Sacitharan,Seint Lwin,George Bou Gharios,James R. Edwards 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Ageing is the primary risk factor for osteoarthritis (OA). A decline in the ageing-associated process of autophagy is suggested as a potential contributor to OA development. Polyamines such as spermidine decrease during ageing, contributing to impaired autophagy and reduced cellular function. However, the role of polyamines and their effect on the regulatory mechanism governing autophagy in aged and arthritic cartilage tissue has not been established. Elucidating if polyamine regulation of autophagy is impaired during ageing and OA in chondrocytes may lead to improved treatment approaches to protect against cartilage degradation. Our results indicate that polyamine synthesis was decreased in aged and OA cartilage, along with reduced autophagy activity, evidenced by decreased autophagyrelated gene and protein expression and autophagosome formation. Importantly, spermidine treatment increased the expression of the acetyltransferase EP300, which binds to crucial autophagy proteins, Beclin1 and LC3, and elevates chondrocyte autophagy. Our data indicate spermidine prevents the ageing- and OA-related decrease in autophagy and may protect against OA development.

Microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to sugars and ethanol: a review

Pradeep Puligundla,Sang-Eun Oh,Chulkyoon Mok 한국탄소학회 2016 Carbon Letters Vol.17 No.-

Lignocellulosic biomass conversion to biofuels such as ethanol and other value-added bio-products including activated carbons has attracted much attention. The development of an efficient, cost-effective, and eco-friendly pretreatment process is a major challenge in lignocellulosic biomass to biofuel conversion. Although several modern pretreatment technologies have been introduced, few promising technologies have been reported. Microwave irradiation or microwave-assisted methods (physical and chemical) for pretreatment (disintegration) of biomass have been gaining popularity over the last few years owing to their high heating efficiency, lower energy requirements, and easy operation. Acid and alkali pretreatments assisted by microwave heating meanwhile have been widely used for different types of lignocellulosic biomass conversion. Additional advantages of microwave-based pretreatments include faster treatment time, selective processing, instantaneous control, and acceleration of the reaction rate. The present review provides insights into the current research and advantages of using microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to fermentable sugars in the process of cellulosic ethanol production.

Assessment of the quality of life in maxillectomy patients : a longitudinal study

Pradeep Kumar,Habib Ahmad Alvi,Jitendra Rao,Balendra Pratap Singh,Sunit Kumar Jurel,Lakshya Kumar,Himanshi Aggarwal 대한치과보철학회 2013 The Journal of Advanced Prosthodontics Vol.5 No.1

PURPOSE. To longitudinally assess the quality of life in maxillectomy patients rehabilitated with obturator prosthesis. MATERIALS AND METHODS. Thirty-six subjects were enrolled in the span of 16 months, out of which six were dropouts. Subjects (age group 20-60 years) with maxillary defects, irrespective of the cause, planned for definite obturator prosthesis, were recruited. The Hindi version of European Organization for Research and Treatment of Cancer, Head and Neck version 1 of Quality of Life Questionnaire was used before surgical intervention and one month after definitive obturator. Questionnaire includes 35 questions related to the patient’ physical health, well being, psychological status, social relation and environmental conditions. The data were processed with statistical package for social science (SPSS). Probability level of P<.05 was considered statistically significant. RESULTS. The quality of life after rehabilitation with obturator prosthesis was 81.48% (±13.64) on average. On item-level, maximum mean scores were obtained for items problem with teeth (1.87 ± 0.94), pain in mouth (1.80 ± 0.92), trouble in eating (1.70 ± 0.88), trouble in talking to other people (1.60 ± 1.22), problems in swallowing solid food (1.57 ± 1.22) and bothering appearance (1.53 ± 1.04); while minimum scores were obtained for the items coughing (1.17 ± 0.38), hoarseness of voice (1.17 ± 0.53), painful throat (1.13 ± 0.43), trouble in having social contacts with friends (1.10 ± 0.40) and trouble having physical contacts with family or friends (1.10 ± 0.31). CONCLUSION. Obturator prosthesis is a highly positive and non-invasive approach to improve the quality of life of patients with maxillectomy defects.

CAUSATIVIZATION IN HIN DI

Pradeep Kumar Das,Choi, Jong-Chan 한국외국어대학교 인도연구소 2017 남아시아연구 Vol.22 No.3

The present paper on causative construction in Hindi presents an alternative view of the phenomenon by scrutinizing the form, function and the context of causative verbs in Hindi. There are several classifications of causative verbs in Hindi in the literature, but there is no formal consensus on the diverse usage of the verbs and everyone has adopted his/her own mechanism to handle the data for causative. The explanations that are given in literature are either complex or unclear and thus there are lots of exceptions. In our attempt, we have tried to focus on the semantics and the morphology of the causative verbs and examine them on the basis of their contextual functions. On the basis of this yardstick, we have proposed a four-way classification of the data of causative verbs in Hindi. We have introduced two new terms; a.) de-transitivized verb b.) pseudo-ditransitive verbs in order to explain the process of causativization in Hindi.

Ultralight and Mechanically Robust Three-Dimensional Ti3C2Tx Aerogel Reinforced by Carbon Nanotube for Electromagnetic Interference Shielding

Pradeep Sambyal,Aamir Iqbal,홍준표,구종민 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.2

Audiological Profile of Adult Persons with Auditory Neuropathy Spectrum Disorders

Pradeep Yuvaraj,Mannarukrishnaiah Jayaram 대한청각학회 2016 Journal of Audiology & Otology Vol.20 No.3

Background and Objectives: The auditory profile of a large number of persons with late onset auditory neuropathy spectrum disorder (ANSD) is recently described in the Indian context. The purpose of study was 1) to profile data on routine audiological parameters, cortical evoked potentials, and temporal processing, 2) to analyze the benefit from hearing aids for persons with ANSD, and 3) to understand the association between benefit from hearing aids and auditory profile. Subjects and Methods: Thirty-eight adults with late onset ANSD and a matched group of 40 normally hearing adults participated in the study. Basic audiological tests, recording of cortical evoked potentials, and temporal processing tests were carried out on both groups of participant while only persons with ANSD were fitted with hearing aid. Results: Subjects in the two groups were significantly different on all the audiological parameters. ANSD group seemed to benefit from hearing aids variably. The mean amplitude of N2 was significantly different between normally-hearing participants and patients with ANSD. Conclusions: Residual temporal processing, particularly amplitude modulation detection seems to be associated with benefit from hearing aids in patients with ANSD.