Comparative Performance of Line Probe Assay (Version 2) and Xpert MTB/RIF Assay for Early Diagnosis of Rifampicin-Resistant Pulmonary Tuberculosis

( Raj Narayan Yadav ),( Binit Kumar Singh ),( Rohini Sharma ),( Jigyasa Chaubey ),( Sanjeev Sinha ),( Pankaj Jorwal ) 대한결핵 및 호흡기학회 2021 Tuberculosis and Respiratory Diseases Vol.84 No.3

Background: The emergence of drug-resistant tuberculosis (TB), is a major menace to cast off TB worldwide. Line probe assay (LPA; GenoType MTBDRplus ver. 2) and Xpert MTB/RIF assays are two rapid molecular TB detection/diagnostic tests. To compare the performance of LPA and Xpert MTB/RIF assay for early diagnosis of rifampicin-resistant (RR) TB in acid-fast bacillus (AFB) smear-positive and negative sputum samples. Methods: A total 576 presumptive AFB patients were selected and subjected to AFB microscopy, Xpert MTB/RIF assay and recent version of LPA (GenoType MTBDRplus assay version 2) tests directly on sputum samples. Results were compared with phenotypic culture and drug susceptibility testing (DST). DNA sequencing was performed with rpoB gene for samples with discordant rifampicin susceptibility results. Results: Among culture-positive samples, Xpert MTB/RIF assay detected Mycobacterium tuberculosis (Mtb) in 97.3% (364/374) of AFB smear-positive samples and 76.5% (13/17) among smear-negative samples, and the corresponding values for LPA test (valid results with Mtb control band) were 97.9% (366/374) and 58.8% (10/17), respectively. For detection of RR among Mtb positive molecular results, the sensitivity of Xpert MTB/RIF assay and LPA (after resolving discordant phenotypic DST results with DNA sequencing) were found to be 96% and 99%, respectively. Whereas, specificity of both test for detecting RR were found to be 99%. Conclusion: We conclude that although Xpert MTB/RIF assay is comparatively superior to LPA in detecting Mtb among AFB smear-negative pulmonary TB. However, both tests are equally efficient in early diagnosis of AFB smear-positive presumptive RR-TB patients.

Research Trends in the Directed Energy Deposition Method of Heterogeneous Materials

Raj Narayan Hajra,Jeoung Han Kim 대한용접·접합학회 2024 대한용접·접합학회지 Vol.42 No.1

Metal Additive Manufacturing (AM) or 3D printing garners attention for economically producing components with superior strength, durability, and corrosion resistance. The microstructure, influenced by factors like heat input, scanning speed, and layer thickness, shapes metal materials intricately in 3D printing.Unlike traditional manufacturing with separate fabrication and post-processing, Multi Materials AM (MM-AM) streamlines the construction of composite structures in a single step using a single machine. Although initial MM-AM, especially inpolymer 3D printing, was simpler, the shift to metal-based MM-AM presents challenges. The distinctive bonding style in MM-AM facilitates robust connections between different metals, minimizing stress concentration and simplifying the joining of diverse metals. Challenges like intermetallic compound formation, residual stress, and material-specific issues leading to cracks persist. Ongoing research focuses on metallurgy, process optimization,and computational simulation to overcome these hurdles. This review delves into current research trends in multi-material AM, identifying pathways for technological advancements. It discusses the application of Directed Energy Deposition (DED)in stacking austenitic and ferritic metals for nuclear power plant cooling system piping’s gradient-form safe-ends. The study emphasizes advanced manufacturing techniques for developing functionally graded materials and dissimilar metal joints, highlighting the transformative potential of additive manufacturing across industries.

Elevated Biochemical Parameters among Individuals with Non-Alcoholic Fatty Liver Disease (NAFLD) in Nepal

( Narayan Prasad Parajuli ),( Shreena Shakya ),( Jyotsna Shakya ),( Puspa Raj Khanal ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Non-alcoholic fatty liver disease (NAFLD) is a spectrum of disease ranging from simple steatosis, through steatohepatitis to fibrosis and ultimately cirrhosis and hepatocellular carcinoma. Globally, NAFLD is being increasingly recognized as a major health burden. In this study, we aimed to investigate the patients with NAFLD and compare various biochemical parameters among patients with and without NAFLD at a tertiary care teaching hospital of Kathmandu, Nepal. Methods: We conducted a hospital based cross sectional study among 143 (73 NAFLD and 70 control) patients visiting a tertiary care teaching hospital of Nepal for their annual medical checkup. Diagnosis of NAFLD was made by abdominal ultrasonography and liver parameters. Analysis of blood chemistry parameters (lipid profile, liver profile and hematology parameters) in the patients with and without NAFLD (control) was carried out by standard methods. Statistical analysis and comparison of the parameters was done by SPSS version 21.0 and data with p value less than 0.05 was considered significant. Results: Among 73 cases diagnosed as NAFLD, ultrasonography revealed 54.7% of the cases as grade I NAFLD, 32.8% as grade II and remaining 12.5% as grade III NAFLD. Mean age for the patient with NAFLD was 41.6 years with male predominance (38, 52.0%). Among the NAFLD cases, 33(45.2%) patients had normal liver profile in which 18(54.5%) of them had abnormal lipid profile. Subsequently, we observed significantly (p<0.001) high levels of fasting blood glucose, serum uric acid, total cholesterol, triglycerides, LDL cholesterol, serum transaminases (AST-ALT) and alkaline phosphatase among NAFLD group of patients. However, no significant difference was noted on blood levels of urea, creatinine and other hematological parameters. Conclusions: Non-alcoholic fatty liver disease was found associated with abnormal biochemical parameters. Timely detection of the cases and establishment of appropriate control measures will be helpful in modifying the disease course and delaying complications.

Hydrophilic nanofibrous structure of polylactide; fabrication and cell affinity

Bhattarai, Shanta Raj,Bhattarai, Narayan,Viswanathamurthi, Periasamy,Yi, Ho Keun,Hwang, Pyoung Han,Kim, Hak Yong Wiley Publishers 2006 Journal of Biomedical Materials Research Part A Vol. No.

<P>Microstructure and architecture of the scaffolds along with the surface chemistry exert profound effect on biological activity (cell distribution, proliferation, and differentiation). For the biological activity, scaffolds in tissue engineering have been widely designed. The objective of this study was to develop hydrophilic nanofibrous structure of polylactides (PLLA) polymer in the form of nonwoven mat by electrospinning technique, and further evaluate the fibroblast NIH3T3 cell proliferation, morphology, and cell–matrix interaction. Hydrophilicity of the PLLA fibers was improved by adding small fraction of low molecular weight polyethylene glycol (PEG) into the electrospinning solution. Four different ratio types (100/0, 80/20, 70/30, and 50/50) of PLLA/PEG electrospun matrices were fabricated, and the pore characteristics, tensile properties, contact angle, and hydrolytic degradation were observed. Furthermore, scanning electron microscope (SEM) and fluorescence actin staining images were used for micro-observation of cell–matrix interaction and cell morphology. It was found that the electrospun mat of PLLA/PEG (80/20), composed of fibers with diameters in the range 540–850 nm, majority of pore diameter less than 100 μm, tensile strength 8 MPa, elongation 150%, porosity more than 90%, and improved hydrophilicity with slow hydrolytic degradation, is favorable for biological activity of NIH3T3 fibroblast cell. Based on these results, the correct composition of PLLA and PEG in the porous electrospun matrix (i.e., PLLA/PEG (80/20)) will be a better candidate rather than other compositions of PLLA/PEG as well as hydrophobic PLLA for application in tissue engineering. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006</P>

Microstructural Evolution and Mechanical Properties of Ti-6Al-4V Alloy through Selective Laser Melting: Comprehensive Study on the Effect of Hot Isostatic Pressing (HIP)

Gargi Roy,Raj Narayan Hajra,Woo Hyeok Kim,Jongwon Lee,Sangwoo Kim,Jeoung Han Kim 한국분말재료학회(구 한국분말야금학회) 2024 한국분말재료학회지 (KPMI) Vol.31 No.1

This study explores the profound impact of varying oxygen content on microstructural and mechanical properties in specimens HO and LO. The higher oxygen concentration in specimen HO is found to significantly influence alpha lath sizes, resulting in a size of 0.5-1 μm, contrasting with the 1-1.5 μm size observed in specimen LO. Pore fraction, governed by oxygen concentration, is high in specimen HO, registering a value of 0.11%, whereas specimen LO exhibits a lower pore fraction (0.02%). Varied pore types in each specimen further underscore the role of oxygen concentration in shaping microstructural morphology. Despite these microstructural variations, the average hardness remains consistent at ~370 HV. This study emphasizes the pivotal role of oxygen content in influencing microstructural features, contributing to a comprehensive understanding of the intricate interplay between elemental composition and material properties.

Adsorption of chromium (VI) on functionalized and non-functionalized carbon nanotubes

Nabisab Mujawar Mubarak,Raj Kogiladas Thines,Noor Rosyidah Sajuni,Ezzat Chan Abdulla,Jaya Narayan Sahu,Poobalan Ganesan,Natesan Subramanian Jayakumar 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.9

We did a comparative study on the adsorption capacity of Cr (VI) between functionalized carbon nanotubes(CNTs) and non-functionalized CNTs. The statistical analysis reveals that the optimum conditions for the highest removalof Cr (VI) are at pH 9, with dosage 0.1 gram, agitation speed and time of 120 rpm and 120 minutes, respectively. Forthe initial concentration of 1.0 mg/l, the removal efficiency of Cr (VI) using functionalized CNTs was 87.6% and 83%of non-functionalized CNTs. The maximum adsorption capacities of functionalized and non–functionalized CNTs were2.517 and 2.49 mg/g, respectively. Langmuir and Freundlich models were adopted to study the adsorption isotherm,which provided a KL and KF value of 1.217 L/mg and 18.14 mg1−nLn/g functionalized CNT, while 2.365 L/mg and 2.307mg1−nLn/g for non-functionalized CNTs. This result proves that functionalized CNTs are a better adsorbent with a higheradsorption capacity compared with the non-functionalized CNTs.

열처리 및 Cu 첨가가 Al-Mg-Si 합금의 미세조직 및 전기화 학적 거동에 미치는 영향에 관한 연구

홍현빈(H. B. Hong),Raj Narayan Hajra,유한결(H. G. Yoo),신은주(E. J. Shin),김재국(J. K. Kim),이종숙(J. S. Lee),김정한(J. H. Kim),김재황(J. H. Kim),조훈휘(H. H. Cho) 한국소성·가공학회 2024 한국소성가공학회 학술대회 논문집 Vol.2024 No.5

Comparative kinetic study of functionalized carbon nanotubes and magnetic biochar for removal of Cd2+ ions from wastewater

Manimaran Ruthiraan,Nabisab Mujawar Mubarak,Raj Kogiladas Thines,Ezzat Chan Abdullah,Jaya Narayan Sahu,Natesan Subramanian Jayakumar,Poobalan Ganesan 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.3

We did a comparative study between functionalized multiwall carbon nanotube (FMWCNTs), and magneticbiochar was carried out to determine the most efficient adsorbent to be employed in the Cd2+ ion removal. Weoptimized parameters such as agitation speed, contact time, pH and adsorbent dosage using design expert vrsion 6.08. The statistical analysis reveals that optimized condition for highest removal of Cd2+ are at pH 5.0, with dosage 1.0 g,agitation speed and contact time of 100 rpm and 90 minutes, respectively. For the initial concentration of 10mg/l, theremoval efficiency of Cd2+ using FMWCNTs was 90% and and 82% of magnetic biochar. The maximum Cd2+ adsorptioncapacities of both FMWCNTs and magnetic biochar were calculated: 83.33mg/g and 62.5mg/g. The Langmuirand Freundlich constants for FMWCNTs were 0.056 L/mg and 13.613 L/mg, while 0.098 L/mg and 25.204 L/mg formagnetic biochar. The statistical analysis proved that FMWCNTs have better adsorption capacity compared to magneticbiochar and both models obeyed the pseudo-second-order.

Stabilization of gold nanoparticles by hydrophobically-modified polycations

Remant Bahadur, K. C.,Aryal, Santosh,Bhattarai, Shanta Raj,Bhattarai, Narayan,Kim, Chi Hun,Kim, Hak Yong Informa UK (TaylorFrancis) 2006 Journal of Biomaterials Science. Polymer Edition Vol.17 No.5

<P>Surface-modified gold nanoparticles have pronounced benefits in the biomedical field due to their significant interaction with delivery materials. In the present study we used hydrophobically-modified polycations (i.e., N-acylated chitosan) to stabilize gold nanoparticles. Aliphatic hydrophobic groups, having carbon chains of different lengths, were first grafted onto the backbone of chitosan by N-acylation with fatty-acid chlorides in order to increase its hydrophobicity. Gold nanoparticles stabilized with native chitosan and N-acylated chitosan were prepared by the graft-onto approach. Chemical modification and its quantification were studied by Fourier-transform infrared (FT-IR) spectroscopy. Further, the stabilized gold nanoparticles were characterized by different physico-chemical techniques such as UV-Vis, FT-IR, TEM, TGA and DLS. Spectral studies of gold nanoparticles show the backbone and the side chain functional groups of chitosan were not cleaved during the conjugation process. TEM observations revealed that the modified chitosan gold nanoparticles were well dispersed and spherical in shape with average size around 10-12 nm in triply-distilled water at pH 7.4, whereas the native chitosan gold nanoparticles appeared as clusters with 9.9 nm as average diameter and were dispersed only in dilute HCl. The size of modified chitosan gold nanoparticles varied depending on the length of grafting molecules.</P>

Effect of Drain Duration and Output on Perioperative Outcomes and Readmissions after Lumbar Spine Surgery

Karamian Brian,Kothari Parth,Toci Gregory,Lambrechts Mark James,Canseco Jose,Mao Jennifer,Narayan Raj,Alfonsi Samuel,Sirch Francis,Kheir Nadim,Semenza Nicholas,Woods Barrett,Rihn Jeffrey,Kurd Mark,Rad 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.2

Study Design: Single-center retrospective cohort.Purpose: To compare surgical outcomes of patients based on lumbar drain variables relating to output and duration. Overview of Literature: The use of drains following lumbar spine surgery, specifically with respect to hospital readmission, postoperative hematoma, postoperative anemia, and surgical site infections, has been controversial.Methods: Patients aged ≥18 years who underwent lumbar fusion with a postoperative drain between 2017 and 2020 were included and grouped based on hospital readmission status, last 8-hour drain output (<40 mL cutoff), or drain duration (2 days cutoff). Total output of all drains, total output of the primary drain, drain duration in days, drain output per day, last 8-hour output, penultimate 8-hour output, and last 8-hour delta (last 8-hour output subtracted by penultimate 8-hour output) were collected. Continuous and categorical data were compared between groups. Multivariate logistic regression analysis and receiver operating characteristic (ROC) analysis were performed to determine whether drain variables can predict hospital readmission, postoperative blood transfusions, and postoperative anemia. Alpha was 0.05.Results: Our cohort consisted of 1,166 patients with 111 (9.5%) hospital readmissions. Results of regression analysis did not identify any of the drain variables as independent predictors of hospital readmission, postoperative blood transfusion, or postoperative anemia. ROC analysis demonstrated the drain variables to be poor predictors of hospital readmission, with the highest area under curve of 0.524 (drain duration), corresponding to a sensitivity of 61.3% and specificity of 49.9%.Conclusions: Drain output or duration did not affect readmission rates following lumbar spine surgery.