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G. Suresh,M. R. Ramesh,M. S. Srinath 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8
This paper reports on a study of the high-temperature tribological performance of self-lubricating nickel-based compositeclad. A porous and crack free clad containing matrix, reinforcement, and lubricant phase is developed on titanium 31 alloyusing microwave irradiation. The microstructure of both NiCrSiB/WC and NiCrSiB/WC/Ag/BaF2 clad revealed very goodmetallurgical bonding with the substrate. The average microhardness of NiCrSiB/WC and NiCrSiB/WC/Ag/BaF2 clad is710.58 HV and 650.25 HV respectively, is comparatively higher than the titanium 31 substrate (320 HV). The addition of Agand BaF2solid lubricants in the clad endowing clad to operate at a broad temperature range. Compared with the NiCrSiB/WCclad, solid lubricant encapsulate clad has shown very low friction coefficient and wear rates. The sliding wear characteristicsof the clad were investigated by varying load and temperatures. The results revealed that oxide phases (NiO and Cr3O)andlubricant phases (Ag and BaWO4)formed at low and high temperatures are adequate to reduce delamination and material loss.
Medical student’s perception to different types of set induction in anatomy lectures
Suresh Narayanan,Suresh Narayanan,Nachiket Shankar,Vimala Ananthy 대한해부학회 2019 Anatomy & Cell Biology Vol.52 No.3
Set induction refers to the process of using a thought-provoking statement, interesting fact, or an audio-visual stimulus at the beginning of lecture to gain student’s attention and give an overview about the lecture topic. In the present study, students were introduced to three types of set induction namely narratives, food-based analogies and humor-based images or activities at the beginning of anatomy lecture and their response to it is collected and analyzed. The objective of the study is to estimate the difference in a questionnaire-based perception score between the three different types of set induction; estimate sex differences in the questionnaire-based perception score. Students rated the validated, 7-item perception questionnaire using a 5-point Likert scale. Students felt that food-based analogies and humor-based images were more interesting, motivated them to participate in lecture-discussion than the narrative set induction. The familiarity of set induction varied between all the three different types of set induction. There was no significant difference in the perception of different types of set induction between male and female undergraduate students. Based on the student’s feedback, it could also serve as a memory aid and ease the students learning experience. Majority of students responded positively to the use of set induction and recommended for its use in future classes.
The Importance of Ubiquitination and Deubiquitination in Cellular Reprogramming
Suresh, Bharathi,Lee, Junwon,Kim, Kye-Seong,Ramakrishna, Suresh Hindawi Publishing Corporation 2016 Stem cells international Vol.2016 No.-
<P>Ubiquitination of core stem cell transcription factors can directly affect stem cell maintenance and differentiation. Ubiquitination and deubiquitination must occur in a timely and well-coordinated manner to regulate the protein turnover of several stemness related proteins, resulting in optimal embryonic stem cell maintenance and differentiation. There are two switches: an E3 ubiquitin ligase enzyme that tags ubiquitin molecules to the target proteins for proteolysis and a second enzyme, the deubiquitinating enzyme (DUBs), that performs the opposite action, thereby preventing proteolysis. In order to maintain stemness and to allow for efficient differentiation, both ubiquitination and deubiquitination molecular switches must operate properly in a balanced manner. In this review, we have summarized the importance of the ubiquitination of core stem cell transcription factors, such as Oct3/4, c-Myc, Sox2, Klf4, Nanog, and LIN28, during cellular reprogramming. Furthermore, we emphasize the role of DUBs in regulating core stem cell transcriptional factors and their function in stem cell maintenance and differentiation. We also discuss the possibility of using DUBs, along with core transcription factors, to efficiently generate induced pluripotent stem cells. Our review provides a relatively new understanding regarding the importance of ubiquitination/deubiquitination of stem cell transcription factors for efficient cellular reprogramming.</P>


T. Suresh,P. Suresh,M. Prabu 한양대학교 청정에너지연구소 2024 Journal of Ceramic Processing Research Vol.25 No.2
In several research studies, many experiments have been conducted on non-traditional Electric Discharge Machining (EDM)and also investigated how different EDM process parameters influence the surface quality and productivity. EDM is a materialremoval process in which desired shape can be obtained by generation of spark. EDM process parameters play the vital role toimprove the surface finish and productivity simultaneously. This paper presents the effects of EDM machining parameter suchas Discharge ON Time, Discharge OFF Time, and Wire Feed, and their interactions on the Material Removal Rate (MRR) andSurface Roughness (SR) during the machining of magnesium matrix composites (MgZE41A) reinforced with Ag and LiAlO2. The hybrid composite of 97Mg+1.5Ag+1.5 LiAlO2 combination is selected for manufacture using powder metallurgy techniqueas it has a high wear resistance. Analysis of Variance (ANOVA) is adopted to study the influencing process parameters for eachresponse. Desirability function analysis (DFA) tool is adopted to find the optimal EDM process parameters which would reducethe surface roughness and improve the material removal rate simultaneously. From the analysis results it has been found thatdesirability ‘D’ of 0.55 gives the better results.
Suresh Patil,Carrilero Luis,Henry Finn 대한정형외과학회 2017 Clinics in Orthopedic Surgery Vol.9 No.3
Background: Hip prostheses with short anatomical stems were designed for metaphyseal fixation and to spare bone stock. We present a study of a short anatomical femoral stem used in all age groups of patients with Dorr A and B type of femora. Methods: We reviewed radiographs of 85 hips in 74 patients who had a cementless total hip arthroplasty with a short anatomical 80 mm femoral stem designed to achieve pure metaphyseal fixation. A ream-only technique was used for femoral canal preparation in all patients. At each follow-up, radiological evaluation was performed for stem alignment, proximal metaphyseal fill, subsidence, status of biological fixation of the femoral stem, heterotrophic ossification, radiolucency, osteolysis, and limb length discrepancy of the stem. Acetabular components were evaluated for positioning, acetabular bone coverage, and radiolucent and osteolytic lesions. Results: The final mean alignment of femoral stem was 2° valgus. The average intramedullary fill by the stem at the proximal level of the lesser trochanter was 93% in the coronal plane and 88% in the sagittal plane. No components were considered to be undersized. Thirteen hips (15.2%) presented radiolucent lines (10 hips < 1 mm in width and 3 hips [3.5%] 2 mm in width) and 100% of them were not progressive with respect to the last follow-up radiograph. All of the stems had excellent fixation by demonstrating bone ingrowth at the latest follow-up. At the last follow-up, heterotopic ossification was noted in 5 hips. The mean preoperative limb length discrepancy was 9.3 mm and the mean postoperative discrepancy was 3.8 mm. The mean acetabular component angle of the 85 components was 41.2° with a mean anteversion of 22.1°. At the last follow-up, there were no revisions of the femoral component. One patient, 25 months after the index operation, required an acetabular component revision because of recurrent hip dislocation. There were no radiological signs of loosening in any of the short-stem prostheses at the last examination. Conclusions: The short, metaphyseal-fitting anatomic cementless femoral stem provided stable fixation without relying on diaphyseal fixation.
Racial Disparity in Time to Surgery and Complications for Hip Fracture Patients
Suresh K. Nayar,Majd Marrache,Iman Ali,Jarred Bressner,Micheal Raad,Babar Shafiq,Uma Srikumaran 대한정형외과학회 2020 Clinics in Orthopedic Surgery Vol.12 No.4
Background: Racial and ethnic disparities in orthopedic surgery may be associated with worse perioperative complications. For patients with hip fractures, studies have shown that early surgery, typically within 24 to 48 hours of admission, may decrease postoperative morbidity and mortality. Our objective was to determine whether race is associated with longer time to surgery from hospital presentation and increased postoperative complications. Methods: We queried the National Surgical Quality Improvement Program database from 2011 to 2017 for patients (> 65 years) with hip fractures who underwent surgical fixation. Patients were identified using Current Procedural Terminology codes (27235, 27236, 27244, and 27245). Delayed surgery was defined as time to surgery from hospital admission that was greater than 48 hours. Time to surgery was compared between races using analysis of variance. A multivariate logistic regression analysis adjusting for comorbidities, age, sex, and surgery was performed to determine the likelihood of delayed surgery and rate of postoperative complications. Results: A total of 58,456 patients who underwent surgery for a hip fracture were included in this study. Seventy-two percent were female patients and the median age was 87 years. The median time to surgery across all patients was 24 hours. African Americans had the longest time to surgery (30.4 ± 27.6 hours) compared to Asians (26.5 ± 24.6 hours), whites (25.8 ± 23.4 hours), and other races (22.7 ± 22.0 hours) (p < 0.001). After adjusting for comorbidities, age, sex, and surgery, there was a 43% increase in the odds of delayed surgery among American Africans compared to whites (odds ratio, 1.43; 95% confidence interval, 1.29–1.58; p < 0.001). Despite higher odds of reintubation, pulmonary embolism, renal insufficiency or failure, and cardiac arrest in African Americans, mortality was significantly lower compared to white patients (4.41% vs. 6.02%, p < 0.001). Asian Americans had the lowest mortality rate (3.84%). Conclusions: A significant disparity in time to surgery and perioperative complications was seen amongst different races with only African Americans having a longer time to surgery than whites. Further study is needed to determine the etiology of this disparity and highlights the need for targeted strategies to help at-risk patient populations.