Rameshwar Adhikari

Tribhuvan University · Central Department of Chemistry

The application of cold plasma therapy for the treatment of cancer is one promising field of study. This therapy can target and kill cancer cells while sparing healthy cells. The reactive oxygen species (ROS) and reactive nitrogen species (RNS), produced during plasma treatment is responsible for the cancer cells death. The research on cold plasma...

For the investigations, scaffolds for bone regeneration (in the form of non-woven mats) were fabricated based on a polymer blend based on polycaprolactone, poly-L-lactic acid and gelatin by electrospinning which were partly modified using vitamin D3 and reinforced with 0 – 12 % nano-hydroxyapatite (nano-HAp extracted from ostrich bones) to improve...

Multi-walled carbon nanotubes and graphite nanoplatelets were functionalized via acid treatment to overcome the problem of agglomeration. Fourier transform infrared spectroscopy showed the chemical modification of the nanocarbons while the general relationship between the chemical treatment and the defects population was analyzed by Raman spectrosc...

Polymer modification by using highly energetic radiations such as gamma rays and the electron beam is a relatively well-established area of research and development. These radiations have been utilized for upgrading the performance of polymeric materials by introducing various architectural modifications and functionalities in the macromolecular ch...

In recent years, considerable attention is given in various nanomaterials development using biodegradable wastes for establishing more eco-friendly technologies. Due to the biocompatible, biodegradable, and non-toxic nature hydroxyapatite (HAp) and chitosan (CS) are highly studied in recent times. In this research work, HAp and CS were synthesized...

The unbalanced lifestyle and rampant use of modern medicine are the leading causes of life-threatening cancer disease prevalence. In the last few decades, chemotherapy and other medication techniques promised to cure cancer. However, cold plasma on cancer cell lines gets little attention due to a lack of understanding of the detailed mechanism of a...

Structural, mechanical, thermal and surface properties comprising biodegradable aromatic–aliphatic polymer poly(butylene adipate-co-terephthalate) (PBAT) and the wheat stalk-based nanocellulose (NCC) were studied. The materials were found to comprise the compatible and yet phase-segregated constituents which kept their identity in the nanocomposite...

Having its root lying in microelectronics, microfluidics seems to hold great potential to explore people's limited knowledge in the field of oncology. It offers numerous advantages such as a low sample volume, minimal cost, parallelization, and portability and has been advanced in the field of molecular biology and chemical synthesis. The platform...

Taking the life of nearly 10 million people annually, cancer has become one of the major causes of mortality worldwide and a hot topic for researchers to find innovative approaches to demystify the disease and drug development. Having its root lying in microelectronics, microfluidics seems to hold great potential to explore our limited knowledge in...

Background The pandemic of Coronavirus Disease 2019 (COVID-19), one of the most infectious diseases in the modern history, is caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and has had a profound health and economic toll, globally. This paper identifies the overall health status associated with COVID-19 pandemic in all 7 pro...

Cellulose nanocrystal (CNC) and polyvinyl alcohol (PVA) nanocomposites are studied as a green alternative to counteract solar panel soiling. CNC synthesized from acid hydrolysis is blended with PVA, and polybutylene terephthalate (PBT) is blended with powdered silica (SiO2) for surface modification to produce a transparent, hydrophobic, and durable...

For bone tissue engineering, nano‐hydroxyapatite (nano‐HAp) is a widely used bioceramic filler in polymer fibrous scaffolds that changes the morphology and micromechanical behavior of fibers. In this study, different volume fraction percentages of nano‐HAp and vitamin D3 (VD3) are incorporated into electrospun polymer blend fibrous scaffolds compri...

Soap and alcohol or alcohol-based cleansers have been used as hand disinfectants and routine hand washing material for a long time. With the COVID-19 being pandemic, there is an increase in the routine use of soap and sanitizers. No doubt washing hands for 20 seconds with proper technique and proper soap could kill the Coronavirus but the effect of...

Soap and alcohol or alcohol-based cleansers have been used as hand disinfectants and routine hand washing material for a long time. With the COVID-19 being pandemic, there is an increase in the routine use of soap and sanitizers. No doubt washing hands for 20 seconds with proper technique and proper soap could kill the Coronavirus but the effect of...

Chitosan (CS), an amino polysaccharide, is a rigid polymer due to the availability of two types of reactive primary and secondary hydroxyl groups (-OH). It is also biodegradable, biocompatible, non-toxic, safe, and antibacterial polymer which makes it applicable in food industry and biomedical applications. Therefore, development of biodegradable f...

Hydroxyapatite nanoparticles were isolated from a biowaste, buffalo bone, via the thermal decomposition method. The resulting white powdered material was characterized by Fourier Transformed Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX) analysis. The FTIR spectra confirm...

Nanocomposites of multiwalled carbon nanotubes (MWCNTs) with poly(butylene adipate-co-terephthalate) (PBAT), a flexible aromatic–aliphatic copolyester, were prepared by melt mixing followed by compression moulding to investigate their spectroscopic, morphological, mechanical and electrical properties. A comparison of the Fourier transform infrared...

Graphene is a promising material whose properties can be tailored by adsorption of molecules on its surface. Amines, with the -NH2 group, act as an electron donating adsorbate. We have investigated via first principles (density functional theory) the adsorption of three different amines, namely aniline, benzylamine and phenethylamine, on graphene s...

Chitosan is a polyfunctional biomaterial that is subjected to chemical modification through functionalization to give the derivatives of remarkable anticancer activity. In this study, functionalization of low molecular weight commercial chitosan (CS) (Mw < 3000 Da, 87% DDA) and high molecular weight crab shell chitosan (CCS) (viscosity average Mw 3...

A balance of mechanical integrity, stiffness, flexibility, and materials performance is one of the most important tasks to be undertaken while designing the conjugated polymer (CP)-based optoelectronic devices. The deformation behavior of such materials in different length scales (molecular, mesoscopic, and macroscopic levels) can be optimized by c...

The current Nepal Science & Technology Report contains six chapters. The first chapter provides a general background with an outline of Nepal’s natural resources and historical account including its indigenous technologies. In 2015, Nepal promulgated a new constitution after embracing a federal setup. The Constitution has included fundamental righ...

3. Overview of STI sectors 3.7 New Frontiers 3.7.2 Nanotechnology Status in Nepal

Structural, thermal and mechanical properties of the compostable composites comprising a biodegradable aliphatic-aromatic copolyester (namely, the poly(butylene adipate-co-terephthalate; PBAT), and microcrystalline cellulose (MCC) derived from agricultural waste, the wheat stalk, were investigated. Purely physical interaction between the components...

In the present work, self-healable rubber blends consisting of modified bromobutyl rubber (BIIR)/natural rubber (NR) blends filled with silica (Si)/carbon nanotube (CNT) hybrid filler were prepared as model system. It was found that an addition of a low loading of silica as secondary filler for CNTs significantly enhances the tensile strength of th...

The Hindu Kush Himalaya (HKH) region has a great diversity of flora and fauna that supports the livelihood and well-being of one fourth of humanity. The HKH hosts four of the 36 ‘biodiversity hotspots’ of the world and is a storehouse of rich agrobiodiversity. The Kangchenjunga Landscape (KL) is a transboundary complex with an area of 25,086...

Nanocomposites of poly(lactic acid) (PLA)/poly(butylene adipate‐co‐terephthalate) (PBAT) blends with multiwalled carbon nanotubes (MWCNTs) were prepared and their morphology, as well as electrical, mechanical, and thermal properties were investigated. The motivation of this work is to prepare electrically conductive and environmentally benign polym...

Electrical electronics waste (E-waste) being of the complex waste has become very tough to manange in environmental friendly manner. Excessive use of hand set mobile phone nowadays would produced larger E-waste soon in future, which would definetly traumatize the world very soon. Moreover the expensive metals and rare earth metals used for smart ap...

A new type of ionomeric nanocomposite based on elastomeric ethylene/1-octene copolymer (EOC) and organophilically modified layered silicate was synthesized through sulfonation of the EOC followed by solution casting. The morphology-mechanical properties correlation of the product was studied with the help of scanning electron microscopy (SEM), atom...

The object of this study has been to investigate the effect of filler dimensionality on morphology and mechanical properties of polymer nanocomposites using various kinds of nanofillers (such as multiwalled carbon nanotubes (1D filler), layered silicate (2D filler), and boehmite (3D filler)) dispersed in the matrix of ethylene-1-octene copolymer (E...

Review Background: Herbs and spices have long been used for both food and medicinal purposes in different world civilizations. In Nepal, various herbs and spices are used for culinary purposes. In addition, a range of bioactive compounds present in herbs and spices have been associated with multiple beneficial health properties. This paper aims to...

ABSTRACT Starch was extracted from potato (Solanum tuberosum) cultivated in Nepal. The yield of starch of different sorts of the species S. tuberosum was compared with each other. Extracted starch (E St.) Kufre Sindure was characterized and compared with commercial starch (Com St.) by the Fourier transform infrared spectroscopy (FTIR). The properti...

Chitosan oligosaccharide and high molecular weight crab shell chitosan were functionalized as imidazole-2-carboxaldehyde chitosan thiosemicarbazones and their copper(II) complexes were synthesized. The synthesized compounds were characterized by FT-IR, 13C NMR, EPR spectroscopy, powder X-ray diffraction (PXRD) analysis, elemental analysis and magne...

We report facile methods of preparing nanosized hydrotalcite-like compounds, the layered double hydroxides (LDH), with ordinary chemistry laboratory settings to educate the young scientists from high schools to undergraduate university level fostering their research interest in preparing these nanomaterials of practical importance. Coprecipitation...

High molecular weight nanocrystalline chitosan (HMWNC)with Mw of 350 kDa and 66.92% DDA was prepared by alkaline N-deacetylation of chitin that was abundantly obtained after demineralization and deproteinization of pulverized crab shells, and commercially available chitosan oligosaccharide (COS) with average Mw< 3000 Da and 87% DDA was encapsulated...

Cell-free DNA (cfDNA) is easily accessible in peripheral blood and can be used as biomarkers for cancer diagnostics, prognostics, and therapeutics. The applications of cfDNA in various areas of cancer management are attracting attention. In this review article, we discuss the potential relevance of using cfDNA analysis in clinical oncology, particu...

Global consciousness towards the organic value of eco-friendly products has attracted the interest of people towards the use of naturally dyed textiles and organic mordants. The present study has been focused not only on exploring the bio-colourant activity of Phyllanthus emblica (Amala) but also on the application of natural mordant for textile dy...

The present work features some simple methods of preparing pure hydroxyapatite nanoparticles (nano-HAp), a useful biomaterial, via various wet chemical methods and using biogenic sources such as eggshells and animal bone. The nano-HAp hence prepared was subsequently characterized by FTIR spectroscopy and XRD technique. The FTIR spectra confirmed th...

Human hair, a common biowaste, can be pyrolyzed to prepare many kinds of functional materials. Pyrolyzed hair has been used as in various forms of traditional medicine, sensor, ink, and electrolytes. This review highlights the major structural characteristics of human hair and its pyrolyzed form. It also addresses the characterization techniques us...

The chemical modification (namely the epoxidation) of a star shaped block copolymer (BCP) based on polystyrene (PS) and polybutadiene (PB) and its effect on structural and mechanical properties of the polymer were investigated. Epoxidation degrees of 37 mol%, 58 mol%, and 82 mol% were achieved by the reaction of the copolymer with meta-chloroperoxy...

With the continued global expansion of COVID-19 transmission and the mounting threat of the disease, the timely analysis of its trend in Nepal and forecasting the potential situation in the country has been deemed necessary. We analyzed the trend, modelling, and impact assessment of COVID-19 cases of Nepal from 23rd January 2020 to 30th April 2020...

Latency of Mycobacterium tuberculosis and prolonged therapy regimen with emergence of MDR (multi-drug resistance) has mandated new therapy and it is prudent new antimicrobials be developed. Taking one of the potent mechanisms of actions of most of the antibiotics of generating reactive oxygen species (ROS) which the resistance bugs tend to mitigate...

A novel natural hydroxyapatite (HAp) bioceramic was extracted from the ostrich cortical bone by the thermal decomposition method. HAp was characterized by different analytical tools such as thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). Remo...

Introduction: Group B streptococci (GBS) are globally recognized as one of the leading causes of neonatal sepsis and meningitis and is also known to cause adverse pregnancy outcomes such as stillbirths and miscarriages. Thus, detailed investigation of GBS in pregnant women has special significance in public health related researches. Objectives:...

Background Crinis Carbonisatus, prepared by pyrolysis of human hair, is traditional Chinese medicine used for increasing blood clotting and wound healing. Its use is explored in literature but no detailed structural study is reported. Objective This work is aimed at studying the chemical and morphological variation of Crinis Carbonisatus under give...

Cellulose fibers were extracted from dried raw corn (Zea mays) husk, is the second most widely traded cereal after wheat, by alkaline treatment (mercerization), followed by neutralization with acid; product of which underwent bleaching to produce pure form of cellulose. Urea-formaldehyde (UF) resin was prepared from formaldehyde and urea and its co...

Background Ghŗ̥ta mūrcchana is a process of pre-treatment recommended in Ayurveda to purify ghee before it can be used for siddha ghŗ̥ta which is claimed to improve the properties of the ghee in general and that of the prepared siddha ghŗ̥ta. Objective This work is aimed at studying the physiochemical properties of ghee and mūrcchita ghŗ̥ta in ord...

Electrical and electronic gadgets (or E-gadgets) have become indispensable components of our daily life these days. As today’s electrical and electronic devices become tomorrow’s waste, the potential hazards of these materials in an open environment are significant, as they can contaminate soil, drinking water, air and thus directly affecting human...

Here we report the comprehensive characterization of the secondary metabolites from the leaves of Colebrookea oppositifolia Smith, a species used as medicinal plant in the traditional medicine of Nepal. Phytochemical screening of bioactives was performed using an integrated LC-MSn and high resolution MS (Mass Spectrometry) approach. Forty-three com...

We communicate briefly about the innovation of protective gear (such as Hazmat suit) and respirator mask that can be used by health care professionals as mouth and nose protection tools against the penetration of the microscopic particles containing highly contagious species into the body. As a research and development support to the local entrepre...

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and first detected in Wuhan, Hubei Province, China in December 2019 and spread across China and abroad. On 11th March 2020, WHO officially declared pandemic on for COVID-19. This review presents transmission mode of the COVID-19 in terms of...

The study has explored the risk scenario via geospatial mapping of temporal transmission trend of COVID-19 in 77 districts of Nepal focusing on the district-wise risk analyses based on present active cases, population density and land entry points from neighboring countries. In overall, low to very high risk zones have been identified. Jhapa, Moran...

In the present study, an attempt has been made to utilize the natural plant dye extracted from petals of Euphorbia pulcherrima (locally called as Lalupate) via green techniques using water as solvent at boiling condition, for fabrics dyeing in combinations with natural mordants such as Aloe vera, Marcha (traditional yeast used in fermentation), and...

With continued global expansion of COVID-19 transmission and mounting threat of the disease, the timely analysis of its trend in Nepal and forecasting the potential situation in the country has been deemed necessary. We analyzed the trend, modelling and impact assessment of COVID-19 cases of Nepal from 23rd January 2020 to 30th April 2020 to portra...

Cancer has been a major global health problem due to its high morbidity and mortality. While many chemotherapy agents have been studied and applied in clinical trials or in clinic, their application is limited due to its toxic side effects and poor tolerability. Monoclonal antibodies specific to the PD-1 and PD-L1 immune checkpoints have been appro...

Streptomyces species are very well known for the production of antimicrobials and enzymes. The objective of this review is to search for the novel Streptomyces isolated in 2018 along with their characteristics and possible antimicrobial properties. The literature search was done according to the PRISMA flow diagram where 28 research papers were eli...

Exosomes affect the initiation and progression of cancers. In the tumor microenvironment, not only cancer cells, but also fibroblasts and immunocytes secrete exosomes. Exosomes act as a communicator between cells by transferring different cargos and microRNAs (miRNAs). Drug resistance is one of the critical factors affecting therapeutic effect in t...

The objective of this research is to employ the natural dyes in dye-sensitized solar cell (DSSC). On account of eco-friendly, renewable, and non-hazardous properties of natural dyes over silicon, a semiconductor, photo-sensitizer in conventional solar cells, cyclohexane extract of Terminalia alata, a natural dye, was employed as photo-sensitizer. T...

Hydroxyapatite (HAp) is a broadly studied bioceramic for biomedical implant and bone tissue regeneration. Despite this, it is a good adsorbent of heavy metal ions. Its chemical formula is Ca10 (PO4)6(OH) 2. It was extracted by the calcination process from Ostrich bone. The obtained HAp was characterized by X-ray diffraction (XRD) and Fourier transf...

Random disposal and accumulation of commodity plastics in the open environment after their end use is an issue that has triggered a lot of concerns both in public and academic debates owing to their seemingly high contribution toward the environmental pollution and potential impacts on biota and human health. Thus, finding the greener solution to t...

Present work explains the synthesis of urea–formaldehyde composites with Allo (Girardinia diversifolia) and cotton (Gossypium arboreum) fibers. Urea–formaldehyde resin was synthesized by condensation polymerization of urea and formaldehyde monomers. Cellulose fibers were extracted by various chemical treatments of natural fibers. Composites were pr...

An agricultural waste, the wheat stalk, was used for the extraction of microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC) via a series of thermochemical and mechanical treatments. The MCC and NCC were then compounded with the biodegradable polymer, poly(butylene adipate‐co‐terephthalate), PBAT, by melt mixing. The properties of th...

Background: Water sources such as lakes, ponds, river etc. have been continuously contaminated by the micro organisms and chemicals. The former can pose a significant threat to human health. This work aims at detecting the bacterial load before and after the sewage treatment and hence isolating pathogens from the sewage before primary treatment and...

The work aims at establishing the optimum conditions for dual thermal and electron beam curing of thermosetting systems modified by styrene/butadiene (SB)-based triblock copolymers in order to develop transparent and toughened materials. The work also investigates the effects of curing procedures on the ultimate phase morphology and mechanical prop...

p>Micro- and nanocrystalline cellulose were extracted from wheat stalk (WS) using different thermomechanical and chemical treatments and characterized by spectroscopic, microscopic and diffraction techniques. The virgin WS fibers were found to be structurally quite similar to the commercial microcrystalline cellulose (MCC). Similar to the commercia...

Micro-and nanocrystalline cellulose were extracted from wheat stalk (WS) using different thermomechanical and chemical treatments and characterized by spectroscopic, microscopic and diffraction techniques. The virgin WS fibers were found to be structurally quite similar to the commercial microcrystalline cellulose (MCC). Similar to the commercial o...