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.

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>

π-Conjugated polyaniline-assisted flexible titania nanotubes with controlled surface morphology as regenerative medicine in nerve cell growth

Shrestha, Bishnu Kumar,Shrestha, Sita,Baral, Ek Raj,Lee, Ji Yeon,Kim, Beom-Su,Park, Chan Hee,Kim, Cheol Sang Elsevier 2019 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.360 No.-

<P><B>Abstract</B></P> <P>Biologically active conjugated polymers, for example polyaniline (PANI), have drawn attention as emerging materials for applications in bio-medical implant devices, due to their inherent abilities with regard to charge-carrier properties, and their ability to immobilize biomolecules or proteins. Herein, we report an electrocoating of PANI on titania nanotubes (TNTs) via electrochemical oxidation of aniline with PANI layers of appropriate thickness (∼274 nm). Uniform titanium oxide nanotubes were first developed from titanium (Ti) foil through an anodization process, followed by calcination to obtain high purity TNTs vertically aligned on a Ti substrate. These had a large surface area, controllable tube height and diameter, and were highly biocompatible, and doping with PANI further improved their properties, like being antibacterial, having a lower charge transfer resistance (22.51 Ω) and strong anti-corrosion behavior (<I>E<SUB>corr</SUB> </I> ∼ − 184 mV, <I>I<SUB>corr</SUB> </I> ∼ 9.7 × 10<SUP>−7</SUP> Amp). <I>In vitro</I> experiments revealed that the cellular functions of PC12 and S42 cells on TNTs-PANI scaffolds show characteristic improvement in proliferation and differentiation owning to approach neuronal cells activation associated with axonal growth and migration in the peripheral nervous system (PNS). Thus, the flexible bioactive substrate is capable of stimulating neuronal cells, and can inspire neural transduction through direct neural interfaces.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A highly conductive electroactive polyaniline (PANI) was electrodeposited uniformly on titania nanotubes (TNTs) substrate. </LI> <LI> Titania nanotubes-polyaniline (TNTs-PANI) showed antibacterial activity and corrosion resistivity. </LI> <LI> The biointerface TNTs-PANI was used as basal substrate for PC12 cells regeneration and differentiation. </LI> <LI> The flexible TNTs-PANI substrate accelerated the neurites outgrowth of PC12 cells. </LI> </UL> </P>

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>

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>