Catalytic combustion of SOFC exhaust gas over supported Pt and Pd catalysts

( Ariful Hoque ),이석배,이휘범,박노국,김기석 한국공업화학회 2010 한국공업화학회 연구논문 초록집 Vol.2010 No.1

Effects of water vapor and temperature upon combustion stability of CeZrO2-modified Pd-Pt/Al2O3 catalyst

Md Ariful Hoque,김기석 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.8

Two bimetallic Pd-Pt catalysts were prepared by wash-coating the composites of Pd-Pt/CeZrO2-Al2O3 ontocordierite monolith and they were evaluated in a tubular reactor for stability in combustion of SOFC stack flue gas atGHSV 29,280 h−1 and 1 atm. The Pd-rich catalyst showed better stability than the Pt-rich catalyst for combustion of thewet feed. Water vapor in the stack flue gas affected the catalyst activity adversely via the formation of inactive Pd(OH)2species at the reaction temperatures of 723 and 823 K, but this effect was eliminated by raising the temperature to 923 Kor above. Catalyst properties such as specific surface area, pore size and metal dispersion did not deteriorate significantlyafter combustion of the wet feed in the temperature range of 723-1,023 K. The presence of CeZrO2 in Al2O3 materialwas considered to affect the support properties favorably, leading to a kind of metal-support interaction beneficial forthe combustion of the wet feed. This interaction helped to enable the Pd-Pt catalysts to maintain good stability for combustingthe wet SOFC stack flue gas with the stoichiometric air-to-fuel ratio at 923 K or above.

Efficacy of strain RB51 vaccine in protecting infection and vertical transmission against Brucella abortus in Sprague-Dawley rats

Md. Ariful Islam,Mst. Minara Khatun,Sung-Il Lee,Byeong-Kirl Baek 대한수의학회 2009 JOURNAL OF VETERINARY SCIENCE Vol.10 No.3

Immunizing animals in the wild against Brucella (B.) abortus is essential to control bovine brucellosis because cattle can get the disease through close contact with infected wildlife. The aim of this experiment was to evaluate the effectiveness of the B. abortus strain RB51 vaccine in protecting infection as well as vertical transmission in Sprague-Dawley (SD) rats against B. abortus biotype 1. Virgin female SD rats (n = 48) two months of age were divided into two groups: one group (n = 24) received RB51 vaccine intraperitoneally with 3 × 1010 colony forming units (CFU) and the other group (n = 24) was used as non-vaccinated control. Non-vaccinated and RB51-vaccinated rats were challenged with 1.5 × 109 CFU of virulent B. abortus biotype 1 six weeks after vaccination. Three weeks after challenge, all rats were bred. Verification of RB51-vaccine induced protection in SD rats was determined by bacteriological, serological and molecular screening of maternal and fetal tissues at necropsy. The RB51 vaccine elicited 81.25% protection in SD rats against infection with B. abortus biotype 1. Offspring from rats vaccinated with RB51 had a decreased (p < 0.05) prevalence of vertical transmission of B. abortus biotype 1 compared to the offspring from non-vaccinated rats (20.23% and 87.50%, respectively). This is the first report of RB51 vaccination efficacy against the vertical transmission of B. abortus in the SD rat model.

Where does arachidonic acid come from in insects?

Md. Ariful Hasan,Yonggyun Kim 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.04

Eicosanoids play crucial roles in mediating insect immune responses. PLA2 releases arachidonic acid (AA) from phospholipids (PLs) and AA is usually used for biosynthesis of eicosanoids. However, AA is little (less than 0.05%) detected in insect PLs. In contrast, insect PLs have a lot of other C18 PUFAs (linoleic acid and linolenic acid). A new hypothesis is that AA is synthesized from C18 precursor by subsequent desaturation and elongation reactions. We predicted several fatty acyl desaturases (DESs) from Spodoptera exigua. Some specific DES inhibitors inhibited eicosanoid-mediated immune responses. Subsequent AA precursor analysis suggests that AA may be synthesized from linolenic acid via the omega-6 pathway.

Genome editing of an insect serotonin receptor using CRISPR-Cas9 and its significance to develop novel insecticides

Md. Ariful Hasan,Yonggyun Kim 한국응용곤충학회 2019 한국응용곤충학회 학술대회논문집 Vol.2019 No.04

A specific serotonin receptor (Se-5HTR) has been identified in the beet armyworm, Spodoptera exigua and classified into 5-HT7 type. Se-5HTR expression was up-regulated in hemocytes and fat body in response to immune challenge. As being a GPCR, this receptor is presumably coupled with intracellular trimeric Gαs protein activating cAMP-dependent protein kinase (PKA) pathway to regulate several cellular functions. RNA interference (RNAi) of Se-5HTR as well as its downstream signal proteins exhibited significant suppression in cellular immune responses including nodulation and phagocytosis. Application of inhibitors to the signaling cascade suppressed the immune responses as well. To validate the Se-5HTR involvement in mediating cellular immunity, 5-HTR knock-out mutants were developed using CRISPR-Cas9 technique and suffered significant developmental anomalies.

N-acetyl-D-glucosamine kinase interacts with dynein light-chain roadblock type 1 at Golgi outposts in neuronal dendritic branch points

Md. Ariful Islam,Syeda Ridita Sharif,이현숙,석대현,문일수 생화학분자생물학회 2015 Experimental and molecular medicine Vol.47 No.-

N-acetylglucosamine kinase (GlcNAc kinase or NAGK) is a ubiquitously expressed enzyme in mammalian cells. Recent studies have shown that NAGK has an essential structural, non-enzymatic role in the upregulation of dendritogenesis. In this study, we conducted yeast two-hybrid screening to search for NAGK-binding proteins and found a specific interaction between NAGK and dynein light-chain roadblock type 1 (DYNLRB1). Immunocytochemistry (ICC) on hippocampal neurons using antibodies against NAGK and DYNLRB1 or dynein heavy chain showed some colocalization, which was increased by treating the live cells with a crosslinker. A proximity ligation assay (PLA) of NAGK-dynein followed by tubulin ICC showed the localization of PLA signals on microtubule fibers at dendritic branch points. NAGK-dynein PLA combined with Golgi ICC showed the colocalization of PLA signals with somal Golgi facing the apical dendrite and with Golgi outposts in dendritic branch points and distensions. NAGKGolgi PLA followed by tubulin or DYNLRB1 ICC showed that PLA signals colocalize with DYNLRB1 at dendritic branch points and at somal Golgi, indicating a tripartite interaction between NAGK, dynein and Golgi. Finally, the ectopic introduction of a small peptide derived from the C-terminal amino acids 74–96 of DYNLRB1 resulted in the stunting of hippocampal neuron dendrites in culture. Our data indicate that the NAGK-dynein-Golgi tripartite interaction at dendritic branch points functions to regulate dendritic growth and/or branching.

N-Acetyl-D-Glucosamine Kinase Promotes the Axonal Growth of Developing Neurons

Md. Ariful Islam,문일수,Syeda Ridita Sharif,이현숙 한국분자세포생물학회 2015 Molecules and cells Vol.38 No.10

N-acetyl-D-glucosamine kinase (NAGK) plays an enzyme activity-independent, non-canonical role in the dendritogenesis of hippocampal neurons in culture. In this study, we investigated its role in axonal development. We found NAGK was distributed throughout neurons until developmental stage 3 (axonal outgrowth), and that its axonal expression remarkably decreased during stage 4 (dendritic outgrowth) and became negligible in stage 5 (mature). Immunocytochemistry (ICC) showed colocalization of NAGK with tubulin in hippocampal neurons and with Golgi in somata, dendrites, and nascent axons. A proximity ligation assay (PLA) for NAGK and Golgi marker protein followed by ICC for tubulin or dynein light chain roadblock type 1 (DYNLRB1) in stage 3 neurons showed NAGK-Golgi complex colocalized with DYNLRB1 at the tips of microtubule (MT) fibers in axonal growth cones and in somatodendritic areas. PLAs for NAGK-dynein combined with tubulin or Golgi ICC showed similar signal patterns, indicating a three way interaction between NAGK, dynein, and Golgi in growing axons. In addition, overexpression of the NAGK gene and of kinase mutant NAGK genes increased axonal lengths, and knockdown of NAGK by small hairpin (sh) RNA reduced axonal lengths; suggesting a structural role for NAGK in axonal growth. Finally, transfection of ‘DYNLRB1 (74-96)’, a small peptide derived from DYNLRB1’s C-terminal, which binds with NAGK, resulted in neurons with shorter axons in culture. The authors suggest a NAGK-dynein-Golgi tripartite interaction in growing axons is instrumental during early axonal development.

Ultrasonic Manipulation of Magnetic Particles in a Microfluidic Channel

Siddique, Ariful Haque,Cho, Seung Hyun,Ahn, Bongyoung,Kim, CheolGi Korean Society for Precision Engineering 2014 International Journal of Precision Engineering and Vol.15 No.7

In microfludic biosensor applications, many kinds of magnetic particles have been employed due to their bioaffinity property, so the appropriate manipulation of magnetic microparticles is important. In this work, we demonstrated the alignment of magnetic beads (diameter <TEX>$2.8{\mu}m$</TEX>) and nanowires (length <TEX>${\leq}6{\mu}m$</TEX> & diameter <TEX>${\approx}$</TEX> 50 nm) using ultrasonic standing wave (USW) in a steel-acrylic microfluidic channel (<TEX>$660{\mu}m$</TEX> width) in the aim of concentrating them to a sensor area to enhance the performance of a sensor. Ultrasonic standing wave field generates the radiation force to concentrate microparticles at the pressure nodal planes. To generate a standing wave inside the channel, an ultrasound of 2.25 MHz resonance frequency was applied as a resonance frequency of the channel. Moreover, it was demonstrated here that the position of the aligned magnetic particles could be controlled by changing the applied frequency. These successful alignment and position control can be a milestone for future research which targets to improve the sensitivity of microfluidic sensors using magnetic particles.

Improvement of COP with Heat Recovery Scheme for Solar Adsorption Cooling System

K. M. Ariful Kabir,Rifat A. Rouf,M. M. A. Sarker,K. C. Amanul Alam,Bidyut B. Saha 대한설비공학회 2018 International Journal Of Air-Conditioning and Refr Vol.26 No.2

Heat recovery ensures optimum usage of the collected energy, and thus, minimizes heat loss for a solar adsorption chiller. Two-bed adsorption chiller with conventional single stage, run by direct solar coupling with heat recovery, has been studied mathematically. In a heat recovery adsorption refrigeration system, to facilitate heat transfer, heat transfer fluid is distributed between two adsorbers maintaining the same mass flow rate. There is no mass transfer between system components during this phase. It is a semi-continuous system performed between two adsorption beds. After completion of desorption/condensation mode, heat transfer fluid is allowed to circulate between the heated desorber and the cooled adsorber. This process distributes some heat of the desorption bed to the adsorber preparing it for the next preheating mode where heat transfer between them is done adiabatically. Consequently, the performance has been checked and a satisfactory increase in the Coefficient of Performance (COP) (approximately 15%) has been detected in the calculated results for the heat recovery operation. It is also observed that the heat recovery process enhances the working hour and overall performances of the solar heat driven adsorption chiller.

N-Acetyl-D-Glucosamine Kinase Promotes the Axonal Growth of Developing Neurons

Islam, Md. Ariful,Sharif, Syeda Ridita,Lee, HyunSook,Moon, Il Soo Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.10

N-acetyl-D-glucosamine kinase (NAGK) plays an enzyme activity-independent, non-canonical role in the dendritogenesis of hippocampal neurons in culture. In this study, we investigated its role in axonal development. We found NAGK was distributed throughout neurons until developmental stage 3 (axonal outgrowth), and that its axonal expression remarkably decreased during stage 4 (dendritic outgrowth) and became negligible in stage 5 (mature). Immunocytochemistry (ICC) showed colocalization of NAGK with tubulin in hippocampal neurons and with Golgi in somata, dendrites, and nascent axons. A proximity ligation assay (PLA) for NAGK and Golgi marker protein followed by ICC for tubulin or dynein light chain roadblock type 1 (DYNLRB1) in stage 3 neurons showed NAGK-Golgi complex colocalized with DYNLRB1 at the tips of microtubule (MT) fibers in axonal growth cones and in somatodendritic areas. PLAs for NAGK-dynein combined with tubulin or Golgi ICC showed similar signal patterns, indicating a three way interaction between NAGK, dynein, and Golgi in growing axons. In addition, overexpression of the NAGK gene and of kinase mutant NAGK genes increased axonal lengths, and knockdown of NAGK by small hairpin (sh) RNA reduced axonal lengths; suggesting a structural role for NAGK in axonal growth. Finally, transfection of 'DYNLRB1 (74-96)', a small peptide derived from DYNLRB1's C-terminal, which binds with NAGK, resulted in neurons with shorter axons in culture. The authors suggest a NAGK-dynein-Golgi tripartite interaction in growing axons is instrumental during early axonal development.