Fabrication of Bismuth Vanadate (BiVO4)Nanoparticles by a Facile Route

M. F. Rahman,M. S. Haque,M. Hasan,M. A. Hakim 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.6

Monoclinic bismuth vanadate (m-BiVO4 ) has attracted many researchers as an advanced photocatalyst for hydrogen production via water splitting and degradation of organic contaminants. In this study, pure m-BiVO4 nanoparticles were fabricated by an easy reproducible solid state route at different temperatures (500 °C, 550 °C, 600 °C, 650 °C and 700 °C) for 2 h. The synthesized materials were characterized by X-ray Diff ractometer where all the diff raction patterns reveal characteristic peaks corresponding to m-BiVO 4 with space group C2/c. Obtained m-BiVO4 particles have the lattice parameters: a = 7.2477 Å, b = 11.6970 Å, c = 5.0900 Å and the volume of the unit cell is 309.23 (106 pm 3 ). Fourier Transform Infrared spectroscopy exhibits formation of Bi–O bond in the prepared nano powders. Ultraviolet–Visible diff use refl ectance spectroscopy suggests that nanostructured BiVO4 particles possess strong energy absorption properties both in visible and ultraviolet region. The particles show red shift of band gap as the calcination temperature rises and possible reasons have been discussed. Energydispersive X-ray spectroscopy confi rms presence of Bi, V, and O without any contaminant, while particle’s morphology was investigated using Field Emission Scanning Electron Microscope.

Evaluation of Wheat Genotypes for Salt Tolerance Based on Some Physiological Traits

Abu Hasan,Hafizur Rahman Hafiz,Nurealam Siddiqui,M. Khatun,Rabiul Islam,Abdullah -Al Mamun 한국작물학회 2015 Journal of crop science and biotechnology Vol.18 No.5

Identification of physiological markers related with salt tolerance during various vegetative and reproductive stages is crucial for evaluating wheat genotypes and improving their salt tolerance. Two salt-tolerant (Shatabdi and BAW 1135) and two salt-sensitive (BARI Gom 26 and BAW 1122) wheat genotypes of Bangladesh were grown in three salinity levels (control, 6 dS m-1, and 12 dS m-1) to observe the sensitivity of some physiological traits.. Salt-tolerant wheat genotypes maintained lower levels of leaf Na, higher levels of leaf K, and greater K/Na ratios in saline conditions than the sensitive one. Due to salt stress, flag leaf proline content was increased in salt-tolerant wheat genotypes whereas the proline level was decreased in the sensitive one compared to the control. Salt-sensitive genotypes showed a greater increment in SPAD (relative chlorophyll content) value at moderate salt stress but a greater reduction in SPAD values at high salt stress than tolerant ones. Salt-sensitive genotypes were affected more in their straw yield and finally grain yield plants-1 under saline conditions than salt-tolerant genotypes. There was a highly significant negative correlation between grain yield and Na content and also a highly significant negative correlation between grain yield and K : Na content of the wheat genotypes under saline environments. We also observed stress susceptibility index (SSI) based on grain yield plant-1 the order of tolerance was BAW 1135 > Shatabdi > BARI Gom 26 > BAW 1122 at moderate salinity level and BAW 1135 > Shatabdi > BAW 1122 > BARI Gom 26 at high salinity

Effects of Sisal/Cotton Interwoven Fabric and Jute Fibers Loading on Polylactide Reinforced Biocomposites

K. M. Faridul Hasan,Czók Csilla,Zsuzsanna Mária Mucsi,Zsófia Kóczán,Péter György Horváth,Miklós Bak,Tibor Alpár 한국섬유공학회 2022 Fibers and polymers Vol.23 No.12

The hybridization effect of sisal/cotton interwoven fabric backed by paper roving with jute woven material isinvestigated in the presence of polylactide (PLA) matrix. The biocomposites (five) were produced through varying different(100/0, 75/25, 50/50, 25/75, and 0/100) proportions of sisal/cotton with jute woven fabrics respectively in the laminates. Afterthe successful reinforcements, mechanical properties were investigated in terms of tensile and flexural tests. Moreover, thewater absorption, thickness swelling, and moisture content tests were also examined for assessing the physical anddimensional stability of developed hybrid composites. The water absorption and thickness swelling tests were carried out inthe presence of water after 2 h and 24 h immersion. The highest mechanical properties were found in case of 100 % sisal/cotton reinforced composites whereas the lowest value was observed in case of 100 % jute fiber. The morphological views ofthe developed materials were also characterized using SEM (Scanning electron microscopy) to observe the surfaces beforeand after the tensile load. The SEM deployed EDX (energy-dispersive X-ray) linear scanning was applied to explore thepresence of different chemicals in the biocomposite systems. The reinforcement effects of different fibers loading incomposite systems were also tested in terms of regression analysis and found that sisal/cotton interwoven fabrics existsignificant influence in the composite systems to increase the mechanical properties.

EXPERIMENTAL INVESTIGATION OF PERFORMANCE IMPROVEMENT OF HOUSEHOLD REFRIGERATOR USING PHASE CHANGE MATERIAL

MD. IMRAN HOSSEN KHAN,HASAN M. M. AFROZ 대한설비공학회 2013 International Journal of Air-Conditioning and Refr Vol.21 No.4

An experimental investigation has been carried out to know about the performance improvement of a household refrigerator using phase change material (PCM). PCMs are used as latent heat thermal storage system to enhance the heat transfer of the evaporator. PCM is located behind the five sides of the evaporator cabinet in which the evaporator coil is immersed. Water (melting point 0C) and Eutectic solutions (melting point 5C) are used as PCMs for this experiment at diffrent thermal loads. Depending on the types of PCM and thermal load, around 20?7% COP improvement of the refrigeration cycle has been observed with PCM with respect to without PCM. With the increase of the quantity of PCM (0.003 to 0.00425 m3?COP increases about 6%. Between two diffrent PCMs the COP improvement for Eutectic solution is higher than Water. The experimental results with PCM confirm that, depending on the thermal load and the types of PCM average compressor running time per cycle is reduced significantly and it is found about 2?6% as compared to without PCM.

Non-cytotoxic Antifungal Agents: Isolation and Structures of Gageopeptides A–D from a <i>Bacillus</i> Strain 109GGC020

Tareq, Fakir Shahidullah,Lee, Min Ah,Lee, Hyi-Seung,Lee, Yeon-Ju,Lee, Jong Seok,Hasan, Choudhury M.,Islam, Md. Tofazzal,Shin, Hee Jae American Chemical Society 2014 Journal of agricultural and food chemistry Vol.62 No.24

<P>Antifungal resistance and toxicity problems of conventional fungicides highlighted the requirement of search for new safe antifungal agents. To comply with the requirement, we discovered four new non-cytotoxic lipopeptides, gageopeptides A–D, <B>1–4,</B> from a marine-derived bacterium <I>Bacillus subtilis</I>. The structures and stereochemistry of gageopeptides were determined by NMR data analysis and chemical means. Gageopeptides exhibited significant antifungal activities against pathogenic fungi <I>Rhizoctonia solani</I>, <I>Botrytis cinerea</I>, and <I>Colletotrichum acutatum</I> with minimum inhibitory concentration (MIC) values of 0.02–0.06 μM. In addition, these lipopeptides showed significant motility inhibition and lytic activities against zoospores of the late blight pathogen <I>Phytophthora capsici</I>. These compounds also showed potent antimicrobial activity against Gram positive and Gram negative bacteria with MIC values of 0.04–0.08 μM. However, gageopeptides A–D did not exhibit any cytotoxicity (GI<SUB>50</SUB> > 25 μM) against cancer cell lines in sulforhodamine B (SRB), 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), and WST-1 ((4-[3–4-iodophenyl]-2-(4-nitrophenyl)-2<I>H</I>-5-tetrazolio)-1,3-benzene disulfonate)) assays, demonstrating that these compounds could be promising candidates for the development of non-cytotoxic antifungal agents.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2014/jafcau.2014.62.issue-24/jf502436r/production/images/medium/jf-2014-02436r_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jf502436r'>ACS Electronic Supporting Info</A></P>

Suspected Bacterial Endophthalmitis Following Sustained-release Dexamethasone Intravitreal Implant: A Case Report

Mücella Arıkan Yorgun,Melek Mutlu,Yasin Toklu,Hasan Basri Çakmak,Nurullah Çağıl 대한안과학회 2014 Korean Journal of Ophthalmology Vol.28 No.3

A 58-year-old man admitted to our opthalmology department with the complaint of branch retinal veinocclusion. He was treated with intravitreal Ozurdex in the right eye. Two days after the injection, the patientpresented with ocular pain and the visual acuity was hand movement. A diagnosis of endophthalmitiswas made. We performed emergent pars plana vitrectomy (PPV) and the implant was removed fromthe vitreous cavity using a retinal forceps. A combination of vancomycin 1.0 mg and amikacin 0.4 mgwas injected intravitreally. However, because of the blurring in the vitreus one week after the procedure,phacoemulsification and a repeat PPV was performed. Five days after the last procedure the signs andsymptoms of endophthalmitis were resolved. Our case demonstrated that endophthalmitis could developafter intravitreal implantation of Ozurdex. Surgical removal of the implant and immediate vitrectomy seemsto be a useful treatment option in these cases.

Analyzing the contact problem of a functionally graded layer resting on an elastic half plane with theory of elasticity, finite element method and multilayer perceptron

Murat Yaylacı,Müjgen Yaylı,Ecren Uzun Yaylacı,Hasan Ölmez,Ahmet Birinci 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.78 No.5

This paper presents a comparative study of analytical method, finite element method (FEM) and Multilayer Perceptron (MLP) for analysis of a contact problem. The problem consists of a functionally graded (FG) layer resting on a half plane and pressed with distributed load from the top. Firstly, analytical solution of the problem is obtained by using theory of elasticity and integral transform techniques. The problem is reduced a system of integral equation in which the contact pressure are unknown functions. The numerical solution of the integral equation was carried out with Gauss-Jacobi integration formulation. Secondly, finite element model of the problem is constituted using ANSYS software and the two-dimensional analysis of the problem is carried out. The results show that contact areas and the contact stresses obtained from FEM provide boundary conditions of the problem as well as analytical results. Thirdly, the contact problem has been extended based on the MLP. The MLP with three-layer was used to calculate the contact distances. Material properties and loading states were created by giving examples of different values were used at the training and test stages of MLP. Program code was rewritten in C++. As a result, average deviation values such as 0.375 and 1.465 was obtained for FEM and MLP respectively. The contact areas and contact stresses obtained from FEM and MLP are very close to results obtained from analytical method. Finally, this study provides evidence that there is a good agreement between three methods and the stiffness parameters has an important effect on the contact stresses and contact areas.

Gageotetrins A–C, Noncytotoxic Antimicrobial Linear Lipopeptides from a Marine Bacterium <i>Bacillus subtilis</i>

Tareq, Fakir Shahidullah,Lee, Min Ah,Lee, Hyi-Seung,Lee, Yeon-Ju,Lee, Jong Seok,Hasan, Choudhury M.,Islam, Md. Tofazzal,Shin, Hee Jae American Chemical Society 2014 ORGANIC LETTERS Vol.16 No.3

<P>Gageotetrins A–C (<B>1</B>–<B>3</B>), a unique class of linear lipopeptides, consisting of di- and tetrapeptides and a new fatty acid were isolated from a Marine <I>Bacillus subtilis</I>. The structures of <B>1</B>–<B>3</B> were assigned by spectroscopic data and their absolute stereochemistries were ascertained by chemical derivatization. Compounds <B>1</B>–<B>3</B> displayed good antimicrobial activities with MIC values of 0.01–0.06 μM. However, these compounds failed to register any cytotoxicity (GI<SUB>50</SUB> > 30 μg/ml) against human cancer cell lines.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2014/orlef7.2014.16.issue-3/ol403657r/production/images/medium/ol-2013-03657r_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol403657r'>ACS Electronic Supporting Info</A></P>

<i>N6</i>-methyladenosine modification of hepatitis B virus RNA differentially regulates the viral life cycle

Imam, Hasan,Khan, Mohsin,Gokhale, Nandan S.,McIntyre, Alexa B. R.,Kim, Geon-Woo,Jang, Jae Young,Kim, Seong-Jun,Mason, Christopher E.,Horner, Stacy M.,Siddiqui, Aleem National Academy of Sciences 2018 Proceedings of the National Academy of Sciences Vol.115 No.35

<P>N6-methyladenosine (m(6)A) RNA methylation is the most abundant epitranscriptomic modification of eukaryotic messenger RNAs (mRNAs). Previous reports have found m(6)A on both cellular and viral transcripts and defined its role in regulating numerous biological processes, including viral infection. Here, we show that m(6)A and its associated machinery regulate the life cycle of hepatitis B virus (HBV). HBV is a DNA virus that completes its life cycle via an RNA intermediate, termed pregenomic RNA (pgRNA). Silencing of enzymes that catalyze the addition of m(6)A to RNA resulted in increased HBV protein expression, but overall reduced reverse transcription of the pgRNA. We mapped the m(6)A site in the HBV RNA and found that a conserved m(6)A consensus motif situated within the epsilon stem loop structure, is the site for m(6)A modification. The epsilon stem loop is located in the 3' terminus of all HBV mRNAs and at both the 5' and 3' termini of the pgRNA. Mutational analysis of the identified m(6)A site in the 5' epsilon stem loop of pgRNA revealed that m(6)A at this site is required for efficient reverse transcription of pgRNA, while m(6)A methylation of the 3' epsilon stem loop results in destabilization of all HBV transcripts, suggesting that m(6)A has dual regulatory function for HBV RNA. Overall, this study reveals molecular insights into how m(6)A regulates HBV gene expression and reverse transcription, leading to an increased level of understanding of the HBV life cycle.</P>

Anther Culture in Crop Plants: Progress and Perspectives

M. Thoihidul Islam(M. Thoihidul Islam ),Mohammad Rashid Arif(Mohammad Rashid Arif ),Md. Toufiq Hasan(Md. Toufiq Hasan ),Arif Hasan Khan Robin(Arif Hasan Khan Robin ) 한국육종학회 2023 Plant Breeding and Biotechnology Vol.11 No.2

A resurrection has started in haploid and double haploid research in the twenty-first century. The haploid and double haploid could be achieved through in vivo and in vitro anther and microspore culture techniques. Fixing the homozygosity is the most striking benefit of androgenesis. Various factors like genotypic dependency, growth condition, developmental stage of the microspore, pre-treatment, culture media, regeneration media, growth hormones, and various chemicals have a direct effect. Wheat, rice, Brassica, and tobacco are the notable crops where anther and microspore culture has been utilized. These haploidy and double haploidy through anther culture served many purposes of basic and applied research. Especially, double haploid cultivars have been cultivating around the globe. In addition, for chromosome mapping, QTL mapping, marker-assisted selection, marker-assisted backcrossing, mutation breeding, genome-wide association study, genomic engineering, and genome editing, androgenesis based haploid and double haploid plants have been exploited due to the effectiveness. Recently, researchers are trying to explain albinism that happens during anther culture from an epigenetic perspective. Further prospects of haploid and doubled haploid research through anther culture have been described in this review.