Tin Layer as a Solid Lubricant for Cold Tube Drawing Processes

Mahesh Patil,Varinder Singh,Amit Kumar Gupta,Srinivasa Prakash Regalla,Tufan Chandra Bera,Bade Simhachalam,Krishna Srinivas 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.2

This paper reports an investigation into the deployment of a thin layer of tin as a lubricant on low carbon steel tube for tube drawing process. The layer was deposited using electro-deposition technique using a green technology of citric acid based electrolyte bath. Coating layer is characterized using SEM, EDS and 3D digital microscopy technique before and after drawing processes. Experimental trials of drawing operation were conducted and promising results were observed with respect to drawing load and surface quality. The observed drawing load is comparable to that with the conventional lubrication system thereby proving the effectiveness of the new proposed lubrication system. The use of proposed lubrication resulted in greatly improved finish as well as better corrosion resistance yielding an additional promise for better value in service life, better market potential as well as a gain on environment front as the proposed method has the potential to eliminate some after operations after drawing as the drawn tube is ready to use after drawing operation.

Effective reduction of <i>p</i>-nitrophenol by silver nanoparticle loaded on magnetic Fe₃O₄/ATO nano-composite

Karki, Hem Prakash,Ojha, Devi Prashad,Joshi, Mahesh Kumar,Kim, Han Joo Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.435 No.-

<P><B>Abstract</B></P> <P>A silver loaded hematite (Fe<SUB>3</SUB>O<SUB>4</SUB>) and antimony doped tin oxide (ATO) magnetic nano-composite (Ag-Fe<SUB>3</SUB>O<SUB>4</SUB>/ATO) was successfully synthesized by in situ one pot green and facile hydrothermal process. The formation of nano-composite, its structure, morphology, and stability were characterized by field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), electron diffraction spectroscopy (EDS), elemental mapping by high resolution scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red spectroscopy (FTIR). UV–vis spectroscopy was used to monitor the catalytic reduction of <I>p</I>-nitrophenol (PNP) into p-aminophenol (PAP) in presence of Ag-Fe<SUB>3</SUB>O<SUB>4</SUB>/ATO nano-composite with excess of sodium borohydride (NaBH<SUB>4</SUB>). The pseudo-first order kinetic equation could describe the reduction of <I>p</I>-nitrophenol with excess of NaBH<SUB>4</SUB>. For the first time, ATO surface was used for hydrothermal growth of silver and iron oxide magnetic nanoparticles. The in situ growth of these nanoparticles provided an effective bonding of components of the nano-composite over the surface of ATO nanoparticles. This nano-composite exhibited easy synthesis, high stability, cost effective and rapid separation using external magnet. The excellent catalytic and anti-bacterial activity of as-synthesized silver nano-composite makes it potential nano-catalyst for waste water treatment as well as biomedical application.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ag-Fe<SUB>3</SUB>O<SUB>4</SUB>/ATO nano-catalyst is synthesized via facile one pot hydrothermal process. </LI> <LI> The common organic water pollutant PNP was reduced into PAP. </LI> <LI> Nano-composite exhibited superior catalytic and anti-bacterial activities. </LI> <LI> Easy separation from reaction system using an external magnet for successive use. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Single-dose intraperitoneal delivery of FK506-encapsulated polymeric microspheres for the alleviation of murine colitis

Shiva Pathak,Shobha Regmi,Mahesh Raj Nepal,Prakash Shrestha,Jeong Uk Choi,Simmyung Yook,Jee-Heon Jeong 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.91 No.-

Based on the severity of the disease progression, the treatment of ulcerative colitis involvesadministration of single or multiple therapeutic agents. In refractory cases of ulcerative colitis, FK506(FK) is the drug of choice in clinics. To maintain a long-term stable blood concentration of FK and toreduce its dosing frequency, we propose single-dose injection of FK-loaded biodegradable microspheres(FK-Ms). FK-Ms were intraperitoneally-injected into mice fed with dextran-sulfate sodium (DSS). Pharmacokinetics study revealed presence of FK in blood for over 20 days. The single intraperitonealinjection of the drug-loaded microspheres effectively alleviated DSS-induced murine colitis. Mechanistically, the single injection of FK-Ms inhibited the infiltration of T cells into colon andattenuated differentiation of T cells into interferon-g secreting Th1 and interleukin-17A secreting Th17cells in colon-draining mesenteric lymph nodes. Therefore, administration of prolonged-release typemicrospheres can be considered as an alternative for the effective treatment of inflammatory boweldiseases.

Stability studies of pure and mixture form of curcuminoids by reverse phase-HPLC method under various experimental stress conditions

Malleswara R. Peram,Sunil S. Jalalpure,Mahesh B. Palkar,Prakash V. Diwan 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.3

Since time immemorial, turmeric has been widely marketed and consumed as dietary supplement due to its diverse medicinal properties. Curcuminoids—comprising a mixture of curcumin (CUR), demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC)—are the prime bioactive constituents of turmeric. However, the usage of curcuminoids is limited by their chemical instability. The lack of information on comparative stability profiles of curcuminoids (in pure and mixture form) prompted us to study how pure curcuminoids and their mixtures behave under different stress degradation conditions. The order of stability of curcuminoids when exposed to acidic, alkaline, and oxidative degradation was found to be as follows: BDMC[DMC[CUR. While the pure and mixture forms of curcuminoids were stable against heat, they completely degraded upon exposure to sunlight. The degradation extent of curcuminoids (in mixture form) was substantially less as compared to their pure form; therefore, this suggested the synergistic stabilizing influence of DMC and BDMC in the curcuminoids’ mixture.

Inflammation-triggered local drug release ameliorates colitis by inhibiting dendritic cell migration and Th1/Th17 differentiation

Regmi, Shobha,Pathak, Shiva,Nepal, Mahesh Raj,Shrestha, Prakash,Park, Junhyeung,Kim, Jong Oh,Yong, Chul Soon,Choi, Dong-Yong,Chang, Jae-Hoon,Jeong, Tae Cheon,Orive, Gorka,Yook, Simmyung,Jeong, Jee-Heo Elsevier 2019 Journal of controlled release Vol.316 No.-

<P><B>Abstract</B></P> <P>Enteric-coated formulations using Eudragit® polymers have been extensively used for delivering drugs to the lower gastrointestinal tract. However, these drug-delivery systems cannot accurately deliver the therapeutic cargoes to colon because of early degradation of the polymers at alkaline pH of the small intestine. Here, we describe a precise method of delivering drugs to inflammation sites in colon using an oral drug delivery system. Tacrolimus (FK506)-loaded microspheres were prepared using a thioketal-based polymer that releases drug in response to reactive oxygen species (ROS), which are abundantly produced at the sites of inflammation in acute colitis. Orally-administered FK506-loaded thioketal microspheres (FK506-TKM) led to a substantial accumulation of FK506 in inflamed colon and effectively alleviated dextran-sulfate sodium (DSS)-induced murine colitis. At the molecular level, FK506-TKM significantly inhibited infiltration of CD4<SUP>+</SUP> and CD8<SUP>+</SUP> T lymphocytes in colon and differentiation of CD4<SUP>+</SUP> T cells into Th1 and Th17 cells in colon-draining mesenteric lymph nodes <I>via</I> restricting dendritic cell migration from colon. Our findings indicate orally-administered thioketal-based drug delivery system as a promising means of treating acute inflammatory bowel diseases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> FK506-loaded ROS-responsive microspheres were prepared and characterized. </LI> <LI> FK506 was accumulated at inflammed colon after oral administration. </LI> <LI> Local delivery of FK506 inhibited colonic dendritic cell migration. </LI> <LI> Effector T cells were attenuated at the colon-draining mesenteric lymph nodes. </LI> <LI> Thioketal polymer-based local drug delivery alleviate inflammation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Bubbling and frothing liquids

Cleary, Paul W.,Pyo, Soon Hyoung,Prakash, Mahesh,Koo, Bon Ki Association for Computing Machinery 2007 ACM transactions on graphics Vol.26 No.3

Proposed Methods for Real-Time Measurement of Posterior Condylar Angle during TKA

( Prateek Behera ),( Devendra Kumar Chouhan ),( Mahesh Prakash ),( Mandeep Dhillon ) 대한슬관절학회 2014 대한슬관절학회지 Vol.26 No.4

purpose: Conventional instruments are known to result in high numbers of outliers in restoring femoral component rotation primarily due to fixed degree of external rotation resection relative to the posterior condylar line (PCL). Outliers can be reduced by determining the patient specific posterior condylar angle (PCA) preoperatively or intraoperatively. There is a paucity of methods that can be used during surgery for determining the PCA. We propose two simple, real-time methods to determine the PCA and hence to measure the axial anatomical variation during surgery. materials and methods: The study was conducted using axial computed tomography (CT) scans of the knees of 26 patients. The commercial software K-PACS and our proposed two methods (trigonometric and protractor) were used to measure the angle between the transepicondylar axis and PCL, i.e., PCA. Statistical comparison between the mean angles obtained by K-PACS and our methods were done. results: The three methods resulted in similar PCAs. The mean PCA measured by the three methods were similar. The mean PCA value measured by the K-PACS, trigonometric method and protractor method was 6.27o (range, 0o to 12o), 6.23o (range, 0o to 11.11o) and 6.31o (range, 0o to 12o), respectively. There were significant correlations between the K-PACS measured PCA and trigonometrically or protractor measured PCA. conclusions: Our novel, simple, easily reproducible, real-time and radiation-free PCA measurement methods obviate the need for preoperative CT scan for identification of patient specific PCA.

Molecular mechanism of the anti-inflammatory and skin protective effects of Syzygium formosum in human skin keratinocytes

이승훈,이난영,최승현,오청해,원건우,Mahesh Prakash Bhatta,문지현,이창규,김종훈,박종일,박종태 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.3

Irradiation injury, especially caused by UVB, of the skin is one of the critical reasons for skin inflammation and damage. The present study aimed to explore the protective effect of Syzygium formosum leafy extract (SFLE) and its mechanism of action against UVB-induced damages of human keratinocytes. In this study, SFLE was prepared from 100 kg dried leaves using industrial-scale processes. We found that SFLE markedly reduced markers of the skin inflammation in UVB-induced pro-inflammatory cytokines. Only 2 μg/mL of SFLE exhibited significantly stronger anti-inflammatory effects than the fivefold concentration of positive control. Intriguingly, an anti-inflammatory enzyme, heme oxygenase-1 expression was significantly induced by SFLE treatment. MMP-3 and -9 were, but not MMP-1, significantly reduced. SFLE inhibited the expression of the MAPK pathway, resulting in a decrease on UVB-induced reactive oxygen species. In conclusion, SFLE can potentially be used to treat skin inflammatory diseases.

Significant Incidence of Extra-Articular Tibia Vara Affects Radiological Outcome of Total Knee Arthroplasty

( Balaji Saibaba ),( Mandeep S Dhillon ),( Devendra K Chouhan ),( Rajendra K Kanojia ),( Mahesh Prakash ),( Vikas Bachhal ) 대한슬관절학회 2015 대한슬관절학회지 Vol.27 No.3

Purpose: To identify and quantify the presence of extra-articular tibia vara that might influence the mechanical axis alignment after total knee arthroplasty (TKA). Materials and Methods: A total of 48 TKAs in 30 osteoarthritic Indian patients were prospectively evaluated. The hip-knee-ankle angle (HKA), joint line convergence angle, and varus angulation at the femur and tibia were measured from the preoperative and postoperative standing hip-to-ankle radiographs. Four different methods were used to measure the varus angulation at the tibia: metaphyseo-diaphyseal angle (MDA), the angle between the anatomical axis and mechanical axis of the tibia, the angle between the proximal third and distal third of tibia and the angle between the proximal half and distal half of tibia. Results: Extra-articular tibia vara quantified using MDA had the most positive correlation with HKA. Receiver operating characteristic plotting showed that MDA of >4o predicts abnormal postoperative HKA. Twenty-eight out of 48 knees had MDA of >4o, and 78.6% of these had postoperative HKA under-correction and 21.4% had less than ideal tibial component position. Conclusions: A significant inherent extra-articular varus angulation best measured using MDA exists in the proximal tibia in osteoarthritic Indian patients undergoing TKA. MDA of >4o is associated with abnormal postoperative HKA. Computer navigation may be useful for achieving ideal correction in such cases.