Metabolic engineering in E. coli for production of C-glycosylated flavones and their physio-chemical studies.

Shrestha,DipeshDhakal,RameshPrasadPandey,Jae Kyung Sohng 한국당과학회 2018 한국당과학회 학술대회 Vol.2018 No.07

Effect of Daylength on the Panicle Exsertion of Panicle Enclosing Gamadi Rice Cultivar

Shrestha,G,L,M,H,Heu,S,Z,Park 한국작물학회 1981 한국작물학회지 Vol.26 No.2

수도의 묘대일수가 절간신장에 미치는 영향

Gyan L. Shrestha갼 랄 슈레스터 韓國作物學會 1985 Korean journal of crop science Vol.30 No.2

네팔에서 보급단계로 진전된 수도 3계통 IET 7251, BG 400-1 및 B 44 b-50-2-2-5-1 을 6월 5일 파종하여 10일, 20일, 30일, 40일, 50일 및 60일 묘를 이앙하고 그들의 출수일수와 절간신장을 조사하여 다음과 같은 결과를 얻었다. 1. 간장은 30일묘 이앙구에서 가장 길었고 그보다 묘대일수가 길어짐에 따라 현저하게 간장이 단축되었다. 2. 육면으로 감별이 가능한 절수도 30일묘 이앙구에서 가장 많았는데 40일묘까지는 큰 차가 없었으나 그보다 묘대기간이 길어지면 유의하게 절수가 감소 되었다. 3. 간장은 40일묘 이앙구에서 가장 길었다. 4. 출수 및 성숙까지의 일수는 이앙이 늦어질수록 증가되었다. Three different improved pre-release rice varieties, when transplanted at different ages of seedlings, showed that 40 day old seedlings produced the longest panicle, whereas 30 day old seedlings produced the highest culm length among treatments in all treated varieties. 40 day or older seedlings reduced the culm length remarkably mainly due to decrease in lower internodes in IET7251 and BG400-1, and due to upper as well as lower internodes in B44b-50-2-2-5-1. 30 day old seedlings produced maximum number of visible internodes. Heading as weil as maturity was delayed with increasing age of seedling.

In vitro에서 큰번데기 동충하초 자실체형성의 불안정성

부샨 쓰레스타 외 한국버섯학회 2004 한국버섯학회지 Vol.2 No.3

Traditionally, Cordyceps species have been used as a part of herbal medicine in Oriental countries, including Korea for internal health, vigor and to cure different diseases related to heart, lung etc. In recent years, research on artificial fruiting of some species of the genus Cordyceps including C. militaris has been carried out extensively because of their medicinal value. Instability observed in the in vitro fruiting of C. militaris is reported in the present study. 전통적으로 Cordyceps종은 한국을 포함한 동양에서 건강증진과 심장과 폐에 관련된 질환을 치료하는 약용식물의 하나로 사용되어왔다. 최근에 동충하초의 약리적 가치 때문에 큰번데기 동충하초를 포함한 몇가지 Cordyceps종의 인공재배에 관한 연구가 활발하게 이루어지고 있다. 본 연구에서는 큰번데기 동충하초를 in vitro에서 인공재배한 결과 자실체 형성이 불안정한 것을 관찰하였기에 보고하고자 한다.

Assessment on Scaling-Up of Mini-Grid Initiative: Case Study of Mini-Grid in Rural Nepal

Pramish Shrestha,Ashish Shrestha,Namrata Tusuju Shrestha,Antonis Papadakis,Ramesh Kumar Maskey 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.1

A majority of Nepalese population are living in rural areas, where the electricity access by grid extension is not feasible. Development of micro-hydropower in the isolated state is one of the solutions to provide the electricity to these areas. However, the micro-hydro systems are facing numerous challenges, such as high investment cost, low reliability, low load factor and protection issues. For this reason, the concept of mini-grid has been developed to address the discussed challenges. In this study, a case study of a mini-grid, which is formed by interconnecting six isolated Micro Hydropower Plants (MHPs) with an installed capacity of 107 kW at a transmission voltage of 11 kV, is considered. This study performs the technical and financial analysis, to study the possibility for scaling up the system. Based on different factors, optimum models have been selected, considering a numbers of different cases including cost–benefit and sensitivity analysis. The mini-grid connection of several isolated MHPs is technically possible, but the financial feasibility depends upon various factors, such as the distance between the MHPs, end-use promotion, total capacity of MHPs, future load growth, promotion mechanisms, power trading with utility, etc. The findings show that sustainable operation of mini-grid requires the local capacity building, coordination, and understanding among community cooperatives.

A new phenolic series of indenopyridinone as topoisomerase inhibitors: Design, synthesis, and structure-activity relationships

Shrestha, Aarajana,Park, Seojeong,Jang, Hae Jin,Katila, Pramila,Shrestha, Ritina,Kwon, Youngjoo,Lee, Eung-Seok Elsevier 2018 Bioorganic & medicinal chemistry Vol.26 No.18

<P><B>Abstract</B></P> <P>DNA Topoisomerase IIα (topo IIα) is one of the most effective therapeutic targets to control cancer. In an effort to develop novel and effective topo IIα targeting anti-proliferative agent, a phenolic series of indenopyridinone and indenopyridinol were designed and prepared using efficient multi-component one pot synthetic method. Total twenty-two synthesized compounds were assessed for topo I and IIα inhibition, and anti-proliferation in three different human cancer cell lines. Overall structure-activity relationship study explored the significance of <I>meta-</I>phenolic group at 4-position and <I>para-</I>phenolic group at 2- and/or 4-position of indenopyridinone skeleton for strong topo IIα-selective inhibition and anti-proliferative activity against human cervix (HeLa) and colorectal (HCT15) cell lines. Compound <B>12</B> with excellent topo IIα inhibition (93.7%) was confirmed as a DNA intercalator that could be a new promising lead to develop effective topo IIα-targeted anticancer agents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Phenolic series of indenopyridinone were synthesized. </LI> <LI> SAR study was performed by comparing topo inhibitory and anti-proliferative activity. </LI> <LI> <I>para-</I>Phenolic group at 2- and/or 4-position of indenopyridinones is important. </LI> <LI> Compound <B>12</B> acted as DNA-intercalative potent topo IIα inhibitor. </LI> <LI> Indenopyridinone as potential scaffold for anticancer activity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

In situ synthesis of cylindrical spongy polypyrrole doped protonated graphitic carbon nitride for cholesterol sensing application

Shrestha, Bishnu Kumar,Ahmad, Rafiq,Shrestha, Sita,Park, Chan Hee,Kim, Cheol Sang Elsevier 2017 Biosensors & bioelectronics Vol.94 No.-

<P><B>Abstract</B></P> <P>Herein, we demonstrate the exfoliation of bulk graphitic carbon nitrides (g-C<SUB>3</SUB>N<SUB>4</SUB>) into ultra-thin (~3.4nm) two-dimensional (2D) nanosheets and their functionalization with proton (g-C<SUB>3</SUB>N<SUB>4</SUB>H<SUP>+</SUP>). The layered semiconductor g-C<SUB>3</SUB>N<SUB>4</SUB>H<SUP>+</SUP> nanosheets were doped with cylindrical spongy shaped polypyrrole (CSPPy-g-C<SUB>3</SUB>N<SUB>4</SUB>H<SUP>+</SUP>) using chemical polymerization method. The as-prepared nanohybrid composite was utilized to fabricate cholesterol biosensors after immobilization of cholesterol oxidase (ChOx) at physiological pH. Large specific surface area and positive charge nature of CSPPy-g-C<SUB>3</SUB>N<SUB>4</SUB>H<SUP>+</SUP> composite has tendency to generate strong electrostatic attraction with negatively charged ChOx, and as a result they formed stable bionanohybrid composite with high enzyme loading. A detailed electrochemical characterization of as-fabricated biosensor electrode (ChOx-CSPPy-g-C<SUB>3</SUB>N<SUB>4</SUB>H<SUP>+</SUP>/GCE) exhibited high-sensitivity (645.7 µAmM<SUP>−1</SUP> cm<SUP>−2</SUP>) in wide-linear range of 0.02–5.0mM, low detection limit (8.0μM), fast response time (~3s), long-term stability, and good selectivity during cholesterol detection. To the best of our knowledge, this novel nanocomposite was utilized for the first time for cholesterol biosensor fabrication that resulted in high sensing performance. Hence, this approach opens a new prospective to utilize CSPPy-g-C<SUB>3</SUB>N<SUB>4</SUB>H<SUP>+</SUP> composite as cost-effective, biocompatible, eco-friendly, and superior electrocatalytic as well as electroconductive having great application potentials that could pave the ways to explore many other new sensors fabrication and biomedical applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Preparation of ultrathin 2D nanosheets of graphite carbon nitride and their protonation. </LI> <LI> Doping of engineered g-C<SUB>3</SUB>N<SUB>4</SUB>H<SUP>+</SUP> nanosheets with cylindrical spongy shaped polypyrrole. </LI> <LI> ChOx immobilization on CSPPy-g-C<SUB>3</SUB>N<SUB>4</SUB>H<SUP>+</SUP> nanohybrid composite to fabricate cholesterol biosensor. </LI> <LI> The biosensor is highly sensitive and reproducible for cholesterol detection. </LI> <LI> The biosensor was applied for the cholesterol detection in human serum samples successfully. </LI> </UL> </P>

Effect of Gibberellic Acid (GA₃) Treated at Various Growth Stages on Internode Contraction and Gamadiness in Rice

Shrestha, G.L.,Heu, M.H. 서울大學校 農科大學 1984 서울대농학연구지 Vol.9 No.2

GA₃처리에 依하여 나타나는 苞內成熟性品種 Gamadi의 節間短縮性이 生育단계別 GA₃처리로 어떻게 變化하는가를 검토하기 위하여 Japonica短稈品種이며 生體內 GA₃合成이 되지 않는 것으로 알려진 Tan-ginbozu와 보통 長稈品種인 Indica의 Pokhareli Mashino 그리고 Gamadi 品種을 發根期, 分얼中期, 幼穗分化期 및 穗孕期에 GA₃처리를 하였다. 그 結果는 다음과 같이 要約된다. 1. 처리에 依한 草丈伸長效果는 分얼中期와 幼穗分化期에서 가장 현저하였고 穗孕期에는 모든 品種에서 效果가 減少되었다. 生育初期의 처리效果는 Gamadi 品種에서 가장 微微하였고 Tan-ginbozu 品種에서 가장 현저하였다. 2. 草丈 伸長效果는 分얼中期에 처리한 것과 그 以後에 1回, 2回, 3回, 4回 처리한 것 들 間에 큰 差가 없었다. 3. 節間短縮에 미친 처리의 영향은 品種과 처리시기에 따라 다르게 나타났다. Tan-ginbozu는 發根期 처리로 稈長全體가 短縮되었고 그 以後의 처리에서는 上位節間들이 伸長되어 全體的으로 長稈이 되었다. Pokhareli Mashine도 上位節間이 伸長되어 全體的으로 長稈이 되었다. Gamadi는 下位節間들의 伸長으로 全體的으로 長稈이 되었지만 幼穗分化期처리로 苞內成숙성과 第3節間의 極端的인 短縮이 이뤄지고 그 以後의 처리로는 穗梗이 若于 伸長되었다. GA₃was treated on the rice cultivars Tan-ginbozu which is a dwarf Japonica, Pakhareli-Mashino which is a tall Indica, and the Gamadi is an Indica and their panicles do not exsert and remain in the sheath of flag leaf, at the growth stages of rooting, mid tillering panicle initiation and booting, to make clear about the influence of growth stages on the internode contraction of Gamadi cultivar by the treatment of GA₃. The results are summarized as follows; 1. The immediate effect of GA₃treatment was most pronounced at mid-tillering and panicle initiation stages and at booting stage it was reduced. At the rooting stage, Gamadi showed least effect and Tanginbozu showed most significant. 2. After mid-tillering stage. the immediate GA₃effect was not different significantly among treatments. 3. GA₃effects on the internode contraction was variable depending on the cultivar and the growth stages treated. Tan ginbozu treated at the rooting stage showed reduction in culm length, but increased it through elongation of upper internodes in other growth stages. Pokhareli-Mashino also increased the culm length the elongation of upper internodes. The Gamadi increased their culm length through elongation of lower internodes, contracted their 1st and 3rd internodes extreamly by the GA₃ treatment at the panicle initiation stage, and showed symptoms of peduncle elongation by the treatment at later growth stage.

Electrodeless coating polypyrrole on chitosan grafted polyurethane with functionalized multiwall carbon nanotubes electrospun scaffold for nerve tissue engineering

Shrestha, Sita,Shrestha, Bishnu Kumar,Kim, Jeong In,Won Ko, Sung,Park, Chan Hee,Kim, Cheol Sang Elsevier 2018 Carbon Vol.136 No.-

<P><B>Abstract</B></P> <P>Herein, we engineered a self-electrical stimulated double-layered nerve guidance conduit (NGC) assembled from electrospun mats with an aligned oriented inward layer covered with a random oriented outer layer. The biomimetic NGC can be achieved from chitosan grafted polyurethane with well-dispersed functionalized multiwall carbon nanotubes (<I>f</I>MWCNTs) nanofibrous mats after a uniform coating of polypyrrole (PPy). The structural framework of interconnected NGC exhibited cellular biomaterial interface and improved the physicochemical properties, including electrical conductivity, mechanical strength, and cytocompatibility, serving as natural hosting substrate to natural extracellular matrices (ECM) for vital roles in nerve tissue engineering. The regrowth, proliferation, and migration, of Schwann cells (S42) and the differentiation of rat pheochromocytoma cells (PC12) were greatly accelerated on the aligned oriented mats as compared to the randomly oriented mats during <I>in vitro</I> cell cultures. The morphology of the spontaneous outgrowth and phenotype of neurite bundles were preferentially guided along the axis of the aligned oriented nanofibers, which maintains a strong adaptability in axonal regeneration. In addition, the differentiation of PC12 cells cultured on as-fabricated NGCs were evaluated from cDNA gene expression. It is hoped that the results will contribute to the efficient application of designed NGCs and can be used in therapeutic strategies for treating injured sites and stimulate recovery from substantial damage to nerve cells.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Properties of ZnO:Al Films Prepared by Spin Coating of Aged Precursor Solution

Shrestha, Shankar Prasad,Ghimire, Rishi,Nakarmi, Jeevan Jyoti,Kim, Young-Sung,Shrestha, Sabita,Park, Chong-Yun,Boo, Jin-Hyo Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.1

Transparent conducting undoped and Al impurity doped ZnO films were deposited on glass substrate by spin coat technique using 24 days aged ZnO precursor solution with solution of ethanol and diethanolamine. The films were characterized by UV-Visible spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), electrical resistivity ($\rho$), carrier concentration (n), and hall mobility ($\mu$) measurements. XRD data show that the deposited film shows polycrystalline nature with hexagonal wurtzite structure with preferential orientation along (002) crystal plane. The SEM images show that surface morphology, porosity and grain sizes are affected by doping concentration. The Al doped samples show high transmittance and better resistivity. With increasing Al concentration only mild change in optical band gap is observed. Optical properties are not affected by aging of parent solution. A lowest resistivity ($8.5 \times 10^{-2}$ ohm cm) is observed at 2 atomic percent (at.%) Al. With further increase in Al concentration, the resistivity started to increase significantly. The decrease resistivity with increasing Al concentration can be attributed to increase in both carrier concentration and hall mobility.