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.

Bio-inspired hybrid scaffold of zinc oxide-functionalized multi-wall carbon nanotubes reinforced polyurethane nanofibers for bone tissue engineering

Shrestha, Bishnu Kumar,Shrestha, Sita,Tiwari, Arjun Prasad,Kim, Jeong-In,Ko, Sung Won,Kim, Han-Joo,Park, Chan Hee,Kim, Cheol Sang Elsevier 2017 Materials & Design Vol.133 No.-

<P><B>Abstract</B></P> <P>In this study, we prepared nanotopographical polyurethane (PU)-based bioactive scaffolds that incorporated uniformly dispersed functionalized multi-wall carbon nanotubes (<I>f</I>MWCNTs) and zinc oxide (ZnO) nanoparticles (NPs) using an electrospinning technique. We found that well dispersed <I>f</I>MWCNTs along with ZnO NPs reinforced PU fibers demonstrated significant improvement in mechanical strength, hydrophilicity, thermal stability, electrical conductivity, degradability, biomineralization, and biocompatibility. Inspired by the exciting nature of biopolymeric composite (PU/ZnO-<I>f</I>MWCNTs) membranes, these hybrid scaffolds offer extensive interest to tissue engineering as a potential biomedical application. The specific bioactive properties and cell-biomaterial interaction of electrospun scaffold containing 0.2wt% ZnO with 0.4wt% <I>f</I>MWCNTs were found to demonstrate anti-bacterial activity and cytocompatibility. Furthermore, the highly charged density, large surface-to-volume ratio, and more functional groups in <I>f</I>MWCNTs integrated on the scaffolds promote osteogenic differentiation of pre-osteoblast (MC3T3-E1) cells. Therefore, the novel as-prepared multifunctional electrospun fibrous scaffold could suggest new avenues for exploration as promising osteoproductive and osteoinductive biomaterials that offer great benefit to bone tissue engineering.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Functionalized multi-wall carbon nanotubes (<I>f</I>MWCNTs) within nanofiber enhance the electrical conductivity of scaffolds. </LI> <LI> The <I>f</I>MWCNTs (0.4 wt%) in scaffolds show good antibacterial activity. </LI> <LI> Interaction of zinc oxide and <I>f</I>MWCNTs with simulated body fluid resulting nucleation of calcium phosphate. </LI> <LI> The bioscaffolds exhibit excellent platform for osteogenic differentiation of pre-osteoblastic cells. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</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.

Investigation of the molecular mechanism of δ-catenin ubiquitination: Implication of β-TrCP-1 as a potential E3 ligase

Shrestha, H.,Yuan, T.,He, Y.,Moon, P.G.,Shrestha, N.,Ryu, T.,Park, S.Y.,Cho, Y.C.,Lee, C.H.,Baek, M.C.,Cho, S.,Simkhada, S.,Kim, H.,Kim, K. Elsevier Biomedical Press 2016 Biochimica et biophysica acta, Molecular cell rese Vol.1863 No.9

Ubiquitination, a post-translational modification, involves the covalent attachment of ubiquitin to the target protein. The ubiquitin-proteasome pathway and the endosome-lysosome pathway control the degradation of the majority of eukaryotic proteins. Our previous study illustrated that δ-catenin ubiquitination occurs in a glycogen synthase kinase-3 (GSK-3) phosphorylation-dependent manner. However, the molecular mechanism of δ-catenin ubiquitination is still unknown. Here, we show that the lysine residues required for ubiquitination are located mainly in the C-terminal portion of δ-catenin. In addition, we provide evidence that β-TrCP-1 interacts with δ-catenin and functions as an E3 ligase, mediating δ-catenin ubiquitin-proteasome degradation. Furthermore, we prove that both the ubiquitin-proteasome pathway and the lysosome degradation pathway are involved in δ-catenin degradation. Our novel findings on the mechanism of δ-catenin ubiquitination will add a new perspective to δ-catenin degradation and the effects of δ-catenin on E-cadherin involved in epithelial cell-cell adhesion, which is implicated in prostate cancer progression.

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>

A conducting neural interface of polyurethane/silk-<i>f</i>unctionalized multiwall carbon nanotubes with enhanced mechanical strength for neuroregeneration

Shrestha, Sita,Shrestha, Bishnu Kumar,Lee, Joshua,Joong, Oh Kwang,Kim, Beom-Su,Park, Chan Hee,Kim, Cheol Sang Elsevier S.A. 2019 Materials Science and Engineering C Vol. No.

<P><B>Abstract</B></P> <P>A fibrous scaffold, fully assimilating polyurethane (PU) and silk fibroin associated with functionalized multi-walled carbon nanotubes (<I>f</I>MWCNTs) was developed by electrospinning technique. Herein, we engineered the PU/Silk fibroin-<I>f</I>MWCNTs-based biomaterial that shows great promise as electrospun scaffolds for neuronal growth and differentiation, because of its unique mechanical properties, hydrophilicity, and biodegradability, with outstanding biocompatibility in nerve tissue engineering. The morphology and structural properties of the scaffolds were studied using various techniques. In particular, the presence of <I>f</I>MWCNTs enhances the electrical conductivity and plausible absorption of sufficient extracellular matrix (ECM). The <I>in vitro</I> tests revealed that the aligned scaffolds (PU/Silk-<I>f</I>MWCNTs) significantly stimulated the growth and proliferation of Schwann cells (S42), together with the differentiation and spontaneous neurite outgrowth of rat pheochromocytoma (PC12) cells that were particularly guided along the axis of fiber alignment. The conductive PU/Silk-<I>f</I>MWCNTs scaffold significantly improves neural expression <I>in vitro</I> with successful axonal regrowth, which was confirmed by immunocytochemistry and qRT-PCR analysis. Inspired by the comprehensive experimental results, the <I>f</I>MWCNTs-based scaffold affords new insight into nerve-guided conduit design from both conductive and protein rich standpoints, and opens a new perspective on peripheral nerve restoration in preclinical applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polyurethane-silk/multiwall carbon nanotubes based aligned electrospun scaffold was fabricated. </LI> <LI> A protein rich biomaterial showed high mechanical strength and good electrical conductivity. </LI> <LI> PC12 cells are well proliferated and differentiated on scaffold along with fibers orientation. </LI> <LI> The scaffold exhibited strong bioactivity, suited for <I>in vitro</I> nerve cell regeneration. </LI> </UL> </P>