Nepal Academy of Science and Technology NAST

Pātan, Nepal

Nepal Academy of Science and Technology NAST

Pātan, Nepal
Time filter
Source Type

Panthi G.,Chonbuk National University | Panthi G.,Nepal Academy of Science and Technology NAST | Park S.-J.,Inha University | Chung H.-J.,Seonam University | And 2 more authors.
Materials Chemistry and Physics | Year: 2017

In the present study, Ag nanoparticles decorated Mn2O3 hybrid nanofibers were fabricated by calcination of electrospun PVP/AgNO3/Mn(NO3)2 precursor nanofibers and characterized by FESEM, EDS, XRD, TEM. It was found that the prepared hybrid nanofibers included tiny Ag nanoparticles (from several to 15 nm) distributed uniformly in the Mn2O3 matrix. The investigation of bactericidal activity towards gram-positive and gram-negative bacteria showed that Ag/Mn2O3 hybrid nanofibers could exhibit enhanced efficiency than that of bare Mn2O3 nanofibers. Therefore, this result suggests that the as prepared Ag/Mn2O3 hybrid nanofibers can be a promising nanomaterial as a good alternative for the development of new bactericides. © 2016 Elsevier B.V.

PubMed | Mahidol University, Tribhuvan University, Louisiana State University, Nepal Academy of Science and Technology NAST and Patan Hospital
Type: | Journal: BioMed research international | Year: 2015

The worldwide increase of multidrug resistance in both community- and health-care associated bacterial infections has impaired the current antimicrobial therapy, warranting the search for other alternatives. We aimed to find the in vitro antibacterial activity of ethanolic extracts of 16 different traditionally used medicinal plants of Nepal against 13 clinical and 2 reference bacterial species using microbroth dilution method. The evaluated plants species were found to exert a range of in vitro growth inhibitory action against the tested bacterial species, and Cynodon dactylon was found to exhibit moderate inhibitory action against 13 bacterial species including methicillin-resistant Staphylococcus aureus, imipenem-resistant Pseudomonas aeruginosa, multidrug-resistant Salmonella typhi, and S. typhimurium. The minimum inhibitory concentration (MIC) values of tested ethanolic extracts were found from 31 to >25,000g/mL. Notably, ethanolic extracts of Cinnamomum camphora, Curculigo orchioides, and Curcuma longa exhibited the highest antibacterial activity against S. pyogenes with a MIC of 49, 49, and 195g/mL, respectively; whereas chloroform fraction of Cynodon dactylon exhibited best antibacterial activity against S. aureus with a MIC of 31g/mL. Among all, C. dactylon, C. camphora, C. orchioides, and C. longa plant extracts displayed a potential antibacterial activity of MIC < 100g/mL.

Angster S.,University of Nevada, Reno | Fielding E.J.,Jet Propulsion Laboratory | Wesnousky S.,University of Nevada, Reno | Pierce I.,University of Nevada, Reno | And 5 more authors.
Seismological Research Letters | Year: 2015

Fault scarps and uplifted terraces in young alluvium are frequent occurrences along the trace of the northerly dipping Himalayan frontal thrust (HFT). Generally, it was expected that the 25 April 2015 M 7.8 Gorkha earthquake of Nepal would produce fresh scarps along the fault trace. Contrary to expectation, Interferometric Synthetic Aperture Radar and aftershock studies soon indicated the rupture of the HFT was confined to the subsurface, terminating on the order of 50 km north of the trace of the HFT. We undertook a field survey along the trace of the HFT and along faults and lineaments within the KathmanduValley eight days after the earthquake. Our field survey confirmed the lack of surface rupture along the HFTand the mapped faults and lineaments in KathmanduValley. The only significant ground deformation we observed was limited to an ∼1-km-long northeast-trending fracture set in the district of Kausaltar within Kathmandu. This feature is interpreted not to be the result of tectonic displacement, but rather a localized extension along a ridge. Our survey also shows the ubiquitous presence of fallen chimneys of brick kilns along the HFT and within the Kathmandu Valley. Measurements of a small subset of fallen chimneys across the region suggest a degree of systematic fall direction of the chimneys when subdivided geographically.

PubMed | Tribhuvan University, International Center for Integrated Mountain Development and Nepal Academy of Science and Technology NAST
Type: Journal Article | Journal: Journal of ethnobiology and ethnomedicine | Year: 2016

Non-timber Forest Products (NTFPs), an important provisioning ecosystem services, are recognized for their contribution in rural livelihoods and forest conservation. Effective management through sustainable harvesting and market driven commercialization are two contrasting aspects that are bringing challenges in development of NTFPs sector. Identifying potential species having market value, conducting value chain analyses, and sustainable management of NTFPs need analysis of their use patterns by communities and trends at a regional scale. We analyzed use patterns, trends, and challenges in traditional use and management of NTFPs in the southern slope of Kangchenjunga Landscape, Eastern Himalaya and discussed potential implications for conservation and livelihoods. A total of 739 species of NTFPs used by the local people of Kangchenjunga Landscape were reported in the reviewed literature. Of these, the highest number of NTFPs was documented from India (377 species), followed by Nepal (363) and Bhutan (245). Though the reported species were used for 24 different purposes, medicinal and edible plants were the most frequently used NTFP categories in the landscape. Medicinal plants were used in 27 major ailment categories, with the highest number of species being used for gastro-intestinal disorders. Though the Kangchenjunga Landscape harbors many potential NTFPs, trade of NTFPs was found to be nominal indicating lack of commercialization due to limited market information. We found that the unsustainable harvesting and lack of marketing were the major constraints for sustainable management of NTFPs sector in the landscape despite of promising policy provisions. We suggest sustainable harvesting practices, value addition at local level, and marketing for promotion of NTFPs in the Kangchenjunga Landscape for income generation and livelihood improvement that subsequently contributes to conservation.

Mishra S.K.,Tribhuvan University | Basukala P.,Tribhuvan University | Basukala O.,Nepal Academy of Science and Technology NAST | Parajuli K.,Tribhuvan University | And 2 more authors.
Current Microbiology | Year: 2014

Microbial biofilms pose great threat for patients requiring indwelling medical devices (IMDs) as it is difficult to remove them. It is, therefore, crucial to follow an appropriate method for the detection of biofilms. The present study focuses on detection of biofilm formation among the isolates from IMDs. We also aimed to explore the antibiogram of biofilm producers. This prospective analysis included 65 prosthetic samples. After isolation and identification of bacteria following standard methodology, antibiogram of the isolates were produced following Kirby–Bauer disc diffusion method. Detection of biofilms was done by tube adherence (TA), Congo red agar and tissue culture plate (TCP) methods. Out of 67 clinical isolates from IMDs, TCP detected 31 (46.3 %) biofilm producers and 36 (53.7 %) biofilm non-producers. Klebsiella pneumoniae, Pseudomonas aeruginosa and Burkholderia cepacia complex were found to be the most frequent biofilm producers. The TA method correlated well with the TCP method for biofilm detection. Higher antibiotic resistance was observed in biofilm producers than in biofilm non-producers. The most effective antibiotics for biofilm producing Gram-positive isolates were Vancomycin and Tigecycline, and that for biofilm producing Gram-negative isolates were Polymyxin-B, Colistin Sulphate and Tigecycline. Nearly 46 % of the isolates were found to be biofilm producers. The antibiotic susceptibility pattern in the present study showed Amoxicillin to be an ineffective drug for isolates from the IMDs. For the detection of biofilm production, TA method can be an economical and effective alternative to TCP method. © 2014, Springer Science+Business Media New York.

Conway K.W.,Texas A&M University | Mayden R.L.,Saint Louis University | Shrestha J.,Nepal Academy of Science and Technology NAST | Edds D.R.,Emporia State University
Ichthyological Exploration of Freshwaters | Year: 2012

Psilorhynchus pseudecheneis is redescribed based on examination of 120 specimens, 16-103 mm SL. It is distinguished from all congeners by its higher number of unbranched pectoral-fin rays and lateral-line scale rows, lower number of circumpeduncular scale rows, absence of scales from the dorsal midline between occiput and mid-point between occiput and dorsal-fin origin, and the presence of large flap-like structures supported by highly modified cycloid scales along the ventral surface of the body between the insertion of the paired fins. Comments on P. homaloptera are also provided. © 2012 by Verlag Dr. Friedrich Pfeil, München, Germany.

Conway K.W.,Texas A&M University | Edds D.R.,Emporia State University | Shrestha J.,Nepal Academy of Science and Technology NAST | Mayden R.L.,Saint Louis University
Journal of Fish Biology | Year: 2011

Turcinoemacheilus himalaya, new species, is described from the Koshi and Gandaki River basins of Nepal. The new species is distinguished from its hypothesised congener, Turcinoemacheilus kosswigi, from the Euphrates, Tigris and Karoun basins of the Middle East, by the presence of small scales on the posterior half of its body (v. absence of all scales), its shorter caudal peduncle (caudal peduncle length 12-15% standard length, L Sv. 16-23), its shorter snout (snout length 28-36% head length, L Hv. 40-49) and by features of its colour pattern, including the presence of small irregularly shaped dark grey markings over the lateral body surface. Turcinoemacheilus himalaya is known to date only from Nepal. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Koirala R.,Nepal Academy of Science and Technology NAST | Taverniti V.,University of Milan | Balzaretti S.,University of Milan | Ricci G.,University of Milan | And 2 more authors.
Microbiological research | Year: 2015

Lactobacillus casei group (Lcs) consists of three phylogenetically closely related species (L. casei, L. paracasei, and L. rhamnosus), which are widely used in the dairy and probiotic industrial sectors. Strategies to easily and rapidly characterize Lcs are therefore of interest. To this aim, we developed a method according to a technique known as high resolution melting analysis (HRMa), which was applied to a 150 bp groEL gene fragment. The analysis was performed on 53 Lcs strains and 29 strains representatives of species that are commonly present in dairy and probiotic products and can be most probably co-isolated with Lcs strains. DNA amplification was obtained only from Lcs strains, demonstrating the specificity of the groEL primers designed in this study. The HRMa clustered Lcs strains in three groups that exactly corresponded to the species of the L. casei group. A following HRMa separated the 39 L. paracasei strains in two well distinct intraspecific groups, indicating the possible existence of at least two distinct genotypes inside the species. Nonetheless, the phenotypic characterization demonstrated that the genotypes do not correspond to the two L. paracasei subspecies, namely paracasei and tolerans. In conclusion, the melting curve analysis developed in this study is demonstrably a simple, labor-saving, and rapid strategy obtain the genotyping of a bacterial isolate and simultaneously potentially confirm its affiliation to the L. casei group of species. The application of this method to a larger collection of strains may validate the possibility to use the proposed HRMa protocol for the taxonomic discrimination of L. casei group of species. In general, this study suggests that HRMa can be a suitable technique for the genetic typization of Lactobacillus strains. Copyright © 2015 Elsevier GmbH. All rights reserved.

Lee D.Y.,Hanyang University | Yoon S.J.,Hanyang University | Shrestha N.K.,Hanyang University | Shrestha N.K.,Nepal Academy of Science and Technology NAST | And 3 more authors.
Microporous and Mesoporous Materials | Year: 2012

In this communication, we explore the cobalt based metal-organic-frameworks (Co-MOF) as a promising material for supercapacitors. The doctor bladed Co-MOF film exhibits a good pseudocapacitor behavior with the specific capacitance up to 206.76 F g -1. The electrochemical redox switching is reversible perfectly for a long run which leads to the loss of only 1.5% in capacitance for 1000 electrochemical life cycle stability test. © 2011 Elsevier Inc. All rights reserved.

Bajracharya G.B.,Nepal Academy of Science and Technology NAST
Fitoterapia | Year: 2015

Bergenin, a natural secondary metabolite, has been isolated from different parts of a number of plants. It is one of active ingredients in herbal and Ayurvedic formulations. It exhibits antiviral, antifungal, antitussive, antiplasmodial, antiinflammatory, antihepatotoxic, antiarrhythmic, antitumor, antiulcerogenic, antidiabetic and wound healing properties. It has been analyzed and estimated in different plant extracts, blood and drug samples using chromatographic techniques, and pharmacokinetic studies have been made. Several bergenin derivatives were isolated and/or synthesized and were found to possess pharmacological activities. Total synthesis of bergenin and its derivatives were reported. This review article covers literature on bergenin and its derivatives until 2013. Ethnomedicinal value of bergenin containing plant materials is also highlighted. This comprehensive review provides information on the potentiality of bergenin and its derivatives for therapeutic usages. © 2015 Published by Elsevier B.V.

Loading Nepal Academy of Science and Technology NAST collaborators
Loading Nepal Academy of Science and Technology NAST collaborators