Sphingosinicella cucumeris sp. nov., isolated from soil of a cucumber garden.

Akter, Shahina,Du, Juan,Won, KyungHwa,Yin, Chang Shik,Kook, MooChang,Yi, Tae-Hoo N.V. Swets en Zeitlinger 2015 Antonie van Leeuwenhoek Vol.108 No.5

<P>A novel bacterial strain, THG-sc1(T), was isolated from a soil sample of a cucumber garden and was characterised by using a polyphasic approach. Cells were observed to be Gram-stain negative, non-motile and rod-shaped. The strain was found to be aerobic, catalase and oxidase positive, esculin and starch negative, and to have an optimum growth temperature and pH of 28??°C and 7.5, respectively. On the basis of 16S rRNA gene sequence analysis, strain THG-sc1(T) was found to belong to the genus Sphingosinicella and to be closely related to Sphingosinicella vermicomposti KCTC 22446(T), followed by Sphingosinicella xenopeptidilytica DSM 17130(T) and Sphingosinicella microcystinivorans KCTC 12019(T). The DNA G+C content was determined to be 60.8??mol% and the predominant respiratory quinone was identified as ubiquinone-10. The major polyamine was found to be sym-homospermidine. The major polar lipids were identified as sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol and an unidentified phospholipid. The major fatty acids were identified as C18:1 ??7c, C16:0 and summed feature 3 (C16:1 ??7c and/or iso-C15:0 2-OH, as defined by MIDI). The results of the genotypic analysis, in combination with chemotaxonomic and physiological data, demonstrated that strain THG-sc1(T) represents a novel species within the genus Sphingosinicella, for which the name Sphingosinicella cucumeris is proposed. The type strain is THG-sc1(T) (=KACC 18279(T)??=??CCTCC AB 2015120(T)).</P>

Stimulated mass enhancement strategy-based highly sensitive detection of a protein in serum using quartz crystal microbalance technique

Akter, Rashida,Jeong, Bongjin,Rahman, Md. Aminur The Royal Society of Chemistry 2015 The Analyst Vol.140 No.4

<P>A stimulated mass enhancement strategy based on enormous biocatalytic precipitation of 4-chloro-1-naphthol using magnetic bead-supported horseradish peroxidase and glucose oxidase bienzymes was developed for the highly sensitive detection of interleukin-6 in serum using a quartz crystal microbalance technique.</P> <P>Graphic Abstract</P><P>A quartz crystal microbalance immunosensor is described for highly sensitive detection of interleukin-6 in serum using a magnetic bead-supported bienzyme-catalyzed stimulated mass enhancement strategy. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4an01555j'> </P>

Side-NSM composite technique for flexural strengthening of RC beams

Akter Hosen,Mohd Zamin Jumaat,A. B. M. Saiful Islam,Abdus Salam,Kim Hung Mo 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.20 No.4

Reinforced concrete (RC) infrastructures often require strengthening due to error in design, degradation of materials properties after prolong utilization and increases load carrying capacity persuaded by new use of the structures. For this purpose, a newly proposed Side Near Surface Mounted (SNSM) composite technique was used for flexural strengthening of RC beam specimens. Analytical and non-linear finite element modeling (FEM) using ABAQUS were performed to predict the flexural performance of RC specimens strengthened with S-NSM using steel bars as a strengthening reinforcement. RC beams with various SNSM reinforcement ratios were tested for flexural performance using four-point bending under monotonic loading condition. Results showed significantly increase the yield and ultimate strengths up to 140% and 144% respectively and improved failure modes. The flexural response, such as failure load, mode of failure, yield load, ultimate load, deflection, strain, cracks characteristic and ductility of the beams were compared with those predicted results. The strengthened RC beam specimens showed good agreement of predicted flexural behavior with the experimental outcomes.

Inner morphological and chemical differentiation of Boehmeria species

Akter, Kazi-Marjahan,Kim, Hye-Jin,Khalil, Atif Ali Khan,Park, Woo Sung,Lee, Mi Kyeong,Park, Jong Hee,Ahn, Mi-Jeong Springer Japan KK 2018 Journal of Natural Medicines Vol.72 No.2

Activation of matrix metalloproteinase-9 (MMP-9) by neurotensin promotes cell invasion and migration through ERK pathway in gastric cancer.

Akter, Hafeza,Park, Min,Kwon, Oh-Seung,Song, Eun Joo,Park, Won-Sang,Kang, Min-Jung Saikon Pub. Co 2015 TUMOR BIOLOGY Vol.36 No.8

<P>Neurotensin (NT) is distributed throughout the brain and gastrointestinal tract. Although the relationship between NT and matrix metalloproteinase-9 (MMP-9) activity in gastric cancer has not been reported, the elevation of MMP-9 and NT is reported in the breast, lung, prostate, and gastric cancer. The aim of our study is to investigate the relationship between NT and MMP-9 activity and the underlying signaling mechanism in gastric cancer cell lines. Commercial ELISA kits were used for estimation of NT and MMP-9 expression, and fluorescence resonance energy transfer (FRET) assay was used for measurement of MMP-9 activity. Cell migration and invasion were determined by wound healing and transwell assay. The expression of signaling proteins was measured by Western blotting. Our study reveals a positive correlation between increased plasma NT and MMP-9 activity in both of patient's serum and gastric cancer cell lines. A dose-dependent elevation of MMP-9 activity was observed by NT treatment in gastric cancer cells (MKN-1 and MKN-45) compared to untreated gastric cancer and normal epithelial cell (HFE-145). Moreover, NT-mediated migration and invasion were observed in gastric cancer cells unlike in normal cell. The signaling mechanism of NT in gastric cancer cells was confirmed in protein kinase C (PKC), extracellular-signal regulated kinase (ERK), and phosphatidylinositol 3-kinase (PI3K) pathway. In addition, pretreatment of gastric cancer cells with NTR1 inhibitor SR48692 was shown to significantly inhibit the NT-mediated MMP-9 activity, cell invasion, and migration. Our finding illustrated NTR1 could be a possible therapeutic target for gastric cancer.</P>

Spectral relaxation computation of electroconductive nanofluid convection flow from a moving surface with radiative flux and magnetic induction

Akter Shahina,Ferdows M,Bég Tasveer A,Bég O Anwar,Kadir A,Sun Shuyu 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.4

A theoretical model is developed for steady magnetohydrodynamic viscous flow resulting from a moving semi-infinite flat plate in an electrically conducting nanofluid. Thermal radiation and magnetic induction effects are included in addition to thermal convective boundary conditions. Buongiorno’s two-component nanoscale model is deployed, which features Brownian motion and thermophoresis effects. The governing nonlinear boundary layer equations are converted to nonlinear ordinary differential equations by using suitable similarity transformations. The transformed system of differential equations is solved numerically, employing the spectral relaxation method (SRM) via the MATLAB R2018a software. SRM is a simple iteration scheme that does not require any evaluation of derivatives, perturbation, and linearization for solving a nonlinear system of equations. Effects of embedded parameters such as sheet velocity parameter$\lambda$, magnetic field parameter$\beta$, Prandtl number$Pr$, magnetic Prandtl number$Prm$, thermal radiation parameter$Rd$, Lewis number$Le$, Brownian motion parameter$Nb$, and thermophoresis parameter$Nt$ on velocity, induced magnetic field, temperature, and nanoparticle concentration profiles are investigated. The skin-friction results, local Nusselt number, and Sherwood number are also discussed for various values of governing physical parameters. To show the convergence rate against iteration, residual error analysis has also been performed. The flow is strongly decelerated, and magnetic induction is suppressed with greater magnetic body force parameter, whereas temperature is elevated due to extra work expended as heat in dragging the magnetic nanofluid. Temperatures are also boosted with increment in nanoscale thermophoresis parameter and radiative parameter, whereas they are reduced with higher wall velocity, Brownian motion, and Prandtl numbers. Both hydrodynamic and magnetic boundary layer thicknesses are reduced with greater reciprocal values of the magnetic Prandtl number Prm. Nanoparticle (concentration) boundary layer thickness is boosted with higher values of thermophoresis and Prandtl number, whereas it is diminished with increasing wall velocity, nanoscale Brownian motion parameter, radiative parameter, and Lewis number. The simulations are relevant to electroconductive nanomaterial processing.

Directors' Remuneration and Performance: Evidence from the Textile Sector of Bangladesh

AKTER, Sharmin,ALI, Md. Hossain,ABEDIN, Md. Thasinul,HOSSAIN, Balal Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.6

This study investigates the impact of board incentives as proxied by directors' remuneration on the financial performance of listed textile companies in Bangladesh. Using Generalized Method of Moments (GMM) and data pertaining to listed textile companies of Dhaka Stock Exchange (DSE) during the period from 2011 to 2017 (resulting in a total of 140 firm-year observations), we have estimated the firm performance equation involving directors' remuneration and board independence as the independent variables and some other control variables like firm age, size, leverage, and operating efficiency. The results reveal that there is a negative association between board remuneration and firm performance. In addition, this study finds no significant relationship between board independence and firm performance of the sample firms. Our findings suggest that higher pay to the board does not stimulate higher firm performance and, in turn, results in shareholders getting nothing in return from this and, hence, is a matter of great concern for them. Moreover, our results indirectly indicate that currently directors' remuneration in Bangladesh is not aligned with the firm performance, which has been emphasized in extant corporate governance literature. Besides, this paper further raises questions about the effectiveness of independent directors in the boards of textile firms in Bangladesh.

Femtomolar detection of cardiac troponin I using a novel label-free and reagent-free dendrimer enhanced impedimetric immunosensor

Akter, Rashida,Jeong, Bongjin,Lee, Yong-Mi,Choi, Jong-Soon,Rahman, Md. Aminur Elsevier 2017 Biosensors & bioelectronics Vol.91 No.-

<P><B>Abstract</B></P> <P>A novel highly sensitive dendrimer coupled impedimetric immunosensor was developed for the label-free and reagent-free detection of cardiac troponin I (TnI) in serum samples. The immunosensor probe was fabricated by covalently attaching carboxylic acid-functionalized third generation (G3) poly (amidoamine) (PAMAM) dendrimer (Den) on the 3, 3′, 5, 5′-tetramethyl benzidine (TMB) modified 6-mercaptohexanoic acid (MHA) self-assembled monolayer (SAM) on a gold (Au) electrode. Monoclonal anti-TnI antibody was then covalently immobilized on the Den and TMB attached MHA SAM modified surface. TMB was used as an internal surface redox couple for generating signal which also allowed to avoid the use of an external one (<I>i.e.</I> ferricyanide couple) in solution during the impedance measurement for monitoring the antibody-antigen binding. On the other hand, Den was used as a signal enhancer by immobilizing more anti-body on the immunosensor probe. The immunosensor probe was characterized using X-ray photoelectron spectroscopy (XPS), quartz crystal microbalance (QCM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. The TnI detection in diluted serum was based on the measurement of charge transfer resistance (<I>R</I> <SUB>ct</SUB>) of the electron transfer process of the surface-attached TMB before and after immunobinding. Under the optimized condition, the proposed immunosensor could detect human TnI in diluted serum samples as low as 11.7 fM with a wide linear dynamic range, good stability, and excellent specificity. The validity of the proposed method was tested in various TnI spiked human undiluted serum samples and was compared with the enzyme-linked immunosorbent assay (ELISA). The results suggested that the proposed immunosensor could be a useful tool for practical applications in clinical diagnosis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Impedance-based cardiac troponin I immunosensor was fabricated. </LI> <LI> Reagent-less and label-free detection was developed using tetramethylbenzidine. </LI> <LI> Enhanced detection was achieved using Dendrimer at the probe. </LI> <LI> Detection limit of troponin I in a diluted serum was as low as 11.7 fM. </LI> </UL> </P>

Validation of Neurotensin Receptor 1 as a Therapeutic Target for Gastric Cancer

Akter, Hafeza,Yoon, Jung Hwan,Yoo, Young Sook,Kang, Min-Jung Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.6

Gastric cancer is the fifth most common type of malignancy worldwide, and the survival rate of patients with advanced-stage gastric cancer is low, even after receiving chemotherapy. Here, we validated neurotensin receptor 1 (NTSR1) as a potential therapeutic target in gastric cancer. We compared NTSR1 expression levels in sixty different gastric cancer-tissue samples and cells, as well as in other cancer cells (lung, breast, pancreatic, and colon), by assessing NTSR1 expression via semi-quantitative real-time reverse transcription polymerase chain reaction, immunocytochemistry and western blot. Following neurotensin (NT) treatment, we analyzed the expression and activity of matrix metalloproteinase-9 (MMP-9) and further determined the effects on cell migration and invasion via wound-healing and transwell assays. Our results revealed that NTSR1 mRNA levels were higher in gastric cancer tissues than non-cancerous tissues. Both of NTSR1 mRNA levels and expression were higher in gastric cancer cell lines relative to levels observed in other cancer-cell lines. Moreover, NT treatment induced MMP-9 expression and activity in all cancer cell lines, which was significantly decreased following treatment with the NTSR1 antagonist SR48692 or small-interfering RNA targeting NTSR1. Furthermore, NT-mediated metastases was confirmed by observing epithelial-mesenchymal transition markers SNAIL and E-cadherin in gastric cancer cells. NT-mediated invasion and migration of gastric cancer cells were reduced by NTSR1 depletion through the Erk signaling. These findings strongly suggested that NTR1 constitutes a potential therapeutic target for the inhibition of gastric cancer invasion and metastasis.

Zooplankton community of Ross Sea, Antarctic Ocean in Austral summer

Akter Masuma,Won-Gyu Park,Hyoung-Sul La 한국수산과학회 양식분과 2020 한국수산과학회 양식분과 학술대회 Vol.2020 No.7