Identification of Histone Deacetylase 2 as a Functional Gene for Skeletal Muscle Development in Chickens

Shahjahan, Md.,Liu, Ranran,Zhao, Guiping,Wang, Fangjie,Zheng, Maiqing,Zhang, Jingjing,Song, Jiao,Wen, Jie Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.4

A previous genome-wide association study (GWAS) exposed histone deacetylase 2 (HDAC2) as a possible candidate gene for breast muscle weight in chickens. The present research has examined the possible role of HDAC2 in skeletal muscle development in chickens. Gene expression was measured by quantitative polymerase chain reaction in breast and thigh muscles during both embryonic (four ages) and post-hatch (five ages) development and in cultures of primary myoblasts during both proliferation and differentiation. The expression of HDAC2 increased significantly across embryonic days (ED) in breast (ED 14, 16, 18, and 21) and thigh (ED 14 and 18, and ED 14 and 21) muscles suggesting that it possibly plays a role in myoblast hyperplasia in both breast and thigh muscles. Transcript abundance of HDAC2 identified significantly higher in fast growing muscle than slow growing in chickens at d 90 of age. Expression of HDAC2 during myoblast proliferation in vitro declined between 24 h and 48 h when expression of the marker gene paired box 7 (PAX7) increased and cell numbers increased throughout 72 h of culture. During induced differentiation of myoblasts to myotubes, the abundance of HDAC2 and the marker gene myogenic differentiation 1 (MYOD1), both increased significantly. Taken together, it is suggested that HDAC2 is most likely involved in a suppressive fashion in myoblast proliferation and may play a positive role in myoblast differentiation. The present results confirm the suggestion that HDAC2 is a functional gene for pre-hatch and post-hatch (fast growing muscle) development of chicken skeletal muscle.

Graphene Oxide-Hydrogen Membrane Fuel Cell

Md Shahjahan Kabir Chowdury,박성범,박용일 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.3

Proton exchange membrane fuel cell (PEMFC) utilizes polymer electrolyte membrane, e.g., Nafi on™, which is a perfl uorosulfonic acid (PFSA) membrane with many disadvantages such as expensive, low mechanical strength, low chemical stability at high temperatures. Meanwhile, graphene oxide membrane (GOM) is an excellent proton conductor at room temperature under humidifi ed conditions. However, graphene oxide membrane fuel cells (GOMFCs) exhibit low maximum power density compared to Nafi on due to fuel gas crossover, membrane degradation and loss of surface functionalities. In this study, bilayer membrane consisting of GOM and hydrogen permeable metal thin fi lm was investigated as electrolyte membrane for hydrogen membrane fuel cell (HMFC). In this fuel cell, the graphene oxide-hydrogen membrane (GOHM) simultaneously plays two roles, an anode catalyst and an electrolyte. A hydrogen permeable metal thin fi lm of about 40 nm was deposited by DC magnetron sputtering at a suitable pressure and deposition time on a 12 μm-thick GOM using a Pd or Ni 64 Zr 36 target to complete the bilayer GOHM electrolyte. The fuel cell performance of the GOHMFC using with Pt-free anode was compared with the GOHMFC with conventional Pt/C electrodes and conventional PEMFC.

Cyclic variations of gonad development of an air-breathing fish, Channa striata in the lentic and lotic environments

Nasim Al Mahmud,Hassan Md. Hafizur Rahman,Golam Mohammod Mostakim,Mohd. Golam Quader Khan,Md. Shahjahan,Nahid Sultana Lucky,M. Sadiqul Islam 한국수산과학회 2016 Fisheries and Aquatic Sciences Vol.19 No.1

The study was conducted to know the cyclic changes in gonadal maturation and to investigate the developmental stages of oocytes and testicular germ cells of an air-breathing fish, Channa striata. Fish were sampled monthly from lentic and lotic environments of three geographical locations of Bangladesh from December to November and the histological analysis of their gonad was done to evaluate the objectives. The highest mean GSI was 5.95 ± 0.20 for female in July and 0.14 ± 0.01 for male also in July showing that the gonadal development reached its peak during this month. The highest mean oocyte diameter was 1257.50 ± 24.17 μm observed in July implying that the oocyte reached maturity in this month. Histological study of ovary revealed the evidence of early yolk granule stage and late yolk granule stage from April to July. In case of male four stages of spermatogenesis were distinguished and spermatozoa were highly abundant in June and July. So the monthly pooled values of GSI and the analysis of gonadal histology indicated that the peak breeding season of C. striata occurred in July in the lentic and lotic environments. Samples collected from lentic and lotic habitats are suggestive of no difference in the development of the gonad. The results of the present study will be useful for selective breeding programme, conservation and sustainable fishery management of C. striata in its natural habitat.

아미노실란을 코팅한 폴리디메틸실록산 필름의 항균 특성

박예지(Yeji Park),정수민(Sumin Jeong),Md Shahjahan Kabir Chowdury,박성범(SungBum Park),박용일(Yong-il Park) 한국고분자학회 2024 폴리머 Vol.48 No.3

Covid-19의 전세계적 대유행에 따라 그 극복을 위한 다양한 연구가 진행되고 있다. 기존의 항균 플라스틱의 경우, 여러가지 항균제를 고분자에 혼합하는 단순한 방법을 사용하는데, 시간에 따라 고분자로부터 용출되어 항균력이 점차 감소하게 되는 단점이 있다. 이를 해결하는 방법으로 매트릭스를 이루는 고분자 사슬에 항균성 작용기를 화학 결합시키는 연구가 진행되고 있다. 양이온을 함유하는 항균성 작용기는 음이온성인 세균의 세포막을 교란 또는 파괴하거나, 세포 안으로 확산해 들어가 대사장애를 일으킴으로써 세균을 사멸시킨다. 본 연구에서는 항균성 작용기의 항균력의 지속과 이의 극대화를 위해 polydimethylsiloxane(PDMS) 필름 표면에 유-무기 복합성 아미노실란 박막을 고밀도로 배열시키는 방법을 사용하였다. 특히 친수성 알콕시 작용기가 기판측과 결합함으로써 아민 작용기가 표면측으로 배향시키는 것이 가능하며, 이로써 항균성의 극대화가 가능하였다. 결과적으로, 아미노실란 하이브리드 코팅층이 우수한 항균력을 보였으며 이로써 기존 항균 플라스틱의 지속성 문제를 해결할 수 있게 되었다. Due to the global pandemic of Covid-19, various studies are being conducted to overcome it. In the case of existing antibacterial plastics, a simple method of mixing various antibacterial agents into a polymer is used, but this has the disadvantage that the antibacterial activity gradually decreases as they are eluted from the polymer over time. To solve this problem, research is underway to chemically bond antibacterial functional groups to the polymer chains that make up the matrix. Antibacterial functional groups such as cations kill bacteria by disrupting or destroying the anionic cell membrane of bacteria, or causing metabolic disorders after diffusing into cells. In this work, we used a method to arrange an organic-inorganic complex aminosilane thin layer on the surface of polydimethylsiloxane (PDMS) film at a high concentration to maintain and maximize the antimicrobial activity. By bonding the hydrophilic alkoxy functional group to the substrate side, it is possible to orient the amine functional group toward the surface, thereby maximizing antibacterial properties. As a result, aminosilane hybrid coating layers showed excellent antibacterial activities and so we could solve the durability problem of the conventional antimicrobial plastics.

Nucleation of Diamond over Nanotube Coated Si Substrate Using Hot Filament Chemical Vapor Deposition (CVD) System

신형식,김길성,Shafeeque G. Ansari,Hyung-Kee Seo,Mushtaq Ahmad Dar,Md. Shahjahan 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.1

We studied the use of carbon nanotubes as a seeding layer for the nucleation of diamond on Si (10) sub-strate by using a hot filament chemical vapor deposition (HFCVD) system. Prior to deposition, substrates were seededwith multi-wal carbon nanotube (MWCNT) powder which was prepared separately. MWCNTs were used as nucle-ation precursors. The diamond grains grew esentialy over the nanotubes with a higher growth density in comparisonwith the un-seeded substrates. The scaning electron microscopy (SEM) image of surface morphology shows crystal-lites of cauliflower shaped grains. The micro Raman spectroscopic results show a sharp peak at 1,332 cm-1 corespond-ing to diamond phase. X-ray photoelectron spectroscopic study show the presence of carbon (C1s) phase.

Nucleation of Diamond over Nanotube Coated Si Substrate Using Hot Filament Chemical Vapor Deposition (CVD) System

Ansari, Shafeeque G.,Seo, Hyung-Kee,Kim, Gil-Sung,Shahjahan, Md.,Shin, Hyung-Shik 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.1

We studied the use of carbon nanotubes as a seeding layer for the nucleation of diamond on Si (100) substrate by using a hot filament chemical vapor deposition (HFCVD) system. Prior to deposition, substrates were seeded with multi-wall carbon nanotube (MWCNT) powder which was prepared separately. MWCNTs were used as nucleation precursors. The diamond grains grew essentially over the nanotubes with a higher growth density in comparison with the un-seeded substrates. The scanning electron microscopy (SEM) image of surface morphology shows crystallites of cauliflower shaped grains. The micro Raman spectroscopic results show a sharp peak at 1,332㎝^(-1) corresponding to diamond phase, X-ray photoelectron spectroscopic study show the presence of carbon (C_(1x)) phase.