Publications by authors named "Narayan Bhattarai"

Fluorescence is a remarkable property exhibited by many chemical compounds and biomolecules. Fluorescence has revolutionized analytical and biomedical sciences due to its wide-ranging applications in analytical and diagnostic tools of biological and environmental importance. Fluorescent molecules are frequently employed in drug delivery, optical sensing, cellular imaging, and biomarker discovery.

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Background: Although there have been reports of COVID-19 breakthrough infections in vaccinated individuals, the vaccines have demonstrated a high efficacy in preventing severe illness and death. Nepal has reported fewer studies of COVID-19 breakthrough infections. Hence, this study has objective to assess the prevalence, and to describe clinical characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) breakthrough infection.

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Metal particles incorporated into polymer matrices in various forms and geometries are attractive material platforms for promoting wound healing and preventing infections. However, the fate of these metal particles and their degraded products in the tissue environment are still unknown, as both can produce cytotoxic effects and promote unwanted wound reactions. In this study, we develop biodegradable fibrous biomaterials embedded with metal particles that have an immune activation functions.

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In contrast to acute diarrhoea, the aetiology of persistent digestive disorders (≥ 14 days) is poorly understood in low-resource settings and conventional diagnostic approaches lack accuracy. In this multi-country study, we compared multiplex real-time PCR for enteric bacterial, parasitic and viral pathogens in stool samples from symptomatic patients and matched asymptomatic controls in Côte d'Ivoire, Mali and Nepal. Among 1826 stool samples, the prevalence of most pathogens was highest in Mali, being up to threefold higher than in Côte d'Ivoire and up to tenfold higher than in Nepal.

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In Nepal, visceral leishmaniasis (VL) has been targeted for elimination as a public health problem by 2026. Recently, increasing numbers of VL cases have been reported from districts of doubtful endemicity including hills and mountains, threatening the ongoing VL elimination program in Nepal. We conducted a multi-disciplinary, descriptive cross-sectional survey to assess the local transmission of Leishmania donovani in seven such districts situated at altitudes of up to 1,764 meters in western Nepal from March to December 2019.

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Background: Visceral leishmaniasis (VL), a life-threatening neglected tropical disease, is targeted for elimination from Nepal by the year 2026. The national VL elimination program is still confronted with many challenges including the increasingly widespread distribution of the disease over the country, local resurgence and the questionable efficacy of the key vector control activities. In this study, we assessed the status and risk of Leishmania donovani transmission based on entomological indicators including seasonality, natural Leishmania infection rate and feeding behavior of vector sand flies, Phlebotomus argentipes, in three districts that had received disease control interventions in the past several years in the context of the disease elimination effort.

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Zinc (Zn) metal and its alloys have received a lot of interest in biomedical applications due to their biodegradability, biocompatibility, antimicrobial activity, and ability to stimulate tissue regeneration. Bulk Zn has been successfully utilized in a variety of implant applications, most notably as bioabsorbable cardiac stents and orthopedic fixation devices, where it provides adequate mechanical properties while also releasing helpful Zn ions (Zn) during degradation. Such beneficial ions are dose-dependent and, when released in excess, can induce cellular toxicity.

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An engineered 3D architectural network of the biopolymeric hydrogel can mimic the native cell environment that promotes cell infiltration and growth. Among several bio-fabricated hydrogel structures, core-shell microcapsules inherit the potential of cell encapsulation to ensure the growth and transport of cells and cell metabolites. Herein, a co-axial electrostatic encapsulation strategy is used to create and encapsulate the cells into chitin nanofibrils integrated alginate hydrogel microcapsules.

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Article Synopsis
  • * Symptoms can mimic tuberculosis, leading to diagnostic delays, with cases presenting issues like productive cough, rusty sputum, chest pain, and pleural effusion.
  • * Two cases were documented where patients were diagnosed through microscopic examination of sputum, treated with praziquantel, and eventually recovered, highlighting the need for awareness of paragonimiasis in similar lung conditions.
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Engineered composite scaffolds composed of natural and synthetic polymers exhibit cooperation at the molecular level that closely mimics tissue extracellular matrix's (ECM) physical and chemical characteristics. However, due to the lack of smooth intermix capability of natural and synthetic materials in the solution phase, bio-inspired composite material development has been quite challenged. In this research, we introduced new bio-inspired material blending techniques to fabricate nanofibrous composite scaffolds of chitin nanofibrils (CNF), a natural hydrophilic biomaterial and poly (ɛ-caprolactone) (PCL), a synthetic hydrophobic-biopolymer.

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Introduction: Existing tests for the diagnosis of pleural tuberculosis (TB) have major limitations in terms of accuracy, time to diagnosis and drug resistance testing. A test which can diagnose pleural TB and detect resistance, like Xpert MTB/Rif, would be optimal for rapid diagnosis and treatment.

Methods: A prospective observational study was done in a tertiary care hospital in Eastern Nepal.

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Background: The Acinetobacter species is an important hospital-acquired pathogen. The rapid development of resistance to multiple drugs and the ability to form biofilm make these bacteria more adaptable to survive in healthcare facilities, thus posing a challenge to their effective management.

Objective: This study aimed to characterize clinical isolates of Acinetobacter spp and to study their antimicrobial susceptibility patterns and ability to form biofilm.

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Zinc oxide nanoparticles (ZnO-NPs) have piqued the curiosity of researchers all over the world due to their extensive biological activity. They are less toxic and biodegradable with the capacity to greatly boost pharmacophore bioactivity. ZnO-NPs are the most extensively used metal oxide nanoparticles in electronic and optoelectronics because of their distinctive optical and chemical properties which can be readily modified by altering the morphology and the wide bandgap.

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Background: Persistent fever, defined as fever lasting for 7 days or more at first medical evaluation, has been hardly investigated as a separate clinical entity in the tropics. This study aimed at exploring the frequencies and diagnostic predictors of the ubiquitous priority (i.e.

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For ongoing malaria elimination programmes, available methods such as microscopy and rapid diagnostic tests (RDTs) cannot detect all malaria cases in acute febrile illness. These methods are entirely dependent on the course of infection, parasite load, and skilled technical resources. Our study objectives were to estimate the performance of light microscopy and a RDT as well as real-time PCR for the detection of the parasite.

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Coumarins are found in higher plants like Rutaceae and Umbelliferae and essential oils of cinnamon bark, cassia leaf, and lavender oil. Coumarin compounds show different biological properties, viz antimicrobial, antibacterial, antifungal, antioxidant, antitumor, anti-HIV, antihypertension, anticoagulant, anticancer, antiviral, anti-inflammatory, analgesics, antidiabetic, anti-depressive, and other bioactive properties. Coumarin and its derivatives possess anticancer activity against different types of cancers such as prostate, renal, breast, laryngeal, lung, colon, CNS, leukemia, malignant melanoma.

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Article Synopsis
  • The isothermal nucleic acid amplification techniques, particularly the recombinase polymerase amplification (RPA) assay, have made it possible to detect pathogenic DNA directly in clinical samples, presenting a new approach in diagnostics over real-time PCR.
  • A multi-country evaluation study was conducted in Bangladesh, India, Nepal, and Sri Lanka on clinical samples from patients with various forms of leishmaniasis to compare the diagnostic effectiveness of the RPA assay against real-time PCR.
  • While real-time PCR showed higher sensitivity in detecting visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL), the RPA assay showed promise but was less sensitive for cutaneous leishmaniasis (CL
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Nanoparticle (NP) toxicity assessment is a critical step in assessing the health impacts of NP exposure to both consumers and occupational workers. assessment models comprising cells cultured in a two-dimensional tissue culture plate (2D-TCP) are an efficient and cost-effective choice for estimating the safety risks of NPs. However, culture of cells in 2D-TCPs distorts cell-integrin and cell-cell interactions and is not able to replicate an phenotype.

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Electrospun nanofiber (EN) technology has been used in the past to generate electrostatically charged multilayer-nanofibers. This platform offers versatile applications including in tissue engineering, drug delivery, wound dressings, and high-efficiency particulate air filters. In this study, we synthesized for the first time nanonet-nanofiber electrospun meshes (NNEMs) of polycaprolactone (PCL)-chitosan (CH) using EN technology.

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Background: Coagulase-negative (CoNS) are a significant cause of hospital-acquired and foreign-body-related infections. We conducted this research to assess methicillin susceptibility of CoNS by disc diffusion, agar dilution, and polymerase chain reaction (PCR) methods and to assess the antimicrobial susceptibility pattern.

Methods: We received 123 CoNS isolates from different specimens including blood, endotracheal tube, and central venous catheter.

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Article Synopsis
  • Nepal's visceral leishmaniasis elimination initiative, launched in 2005, aimed to determine if the transmission of Leishmania donovani had decreased over the years, specifically comparing seroprevalence data from 2006 to 2016.
  • A repeat survey involving 6,609 individuals showed a significant reduction in seroprevalence across all age groups, particularly in children under 10, with a drop from 4.1% in 2006 to 0.5% in 2016, indicating a successful decrease in transmission.
  • The study concludes that the decline in transmission correlates with the elimination program's efforts, and the direct agglutination test (DAT) is a
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Whole genome sequencing (WGS) is increasingly used for molecular diagnosis and epidemiology of infectious diseases. Current Leishmania genomic studies rely on DNA extracted from cultured parasites, which might introduce sampling and biological biases into the subsequent analyses. Up to now, direct analysis of Leishmania genome in clinical samples is hampered by high levels of human DNA and large variation in parasite load in clinical samples.

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Nano-in-micro (NIM) system is a promising approach to enhance the performance of devices for a wide range of applications in disease treatment and tissue regeneration. In this study, polymeric nanofibre-integrated alginate (PNA) hydrogel microcapsules were designed using NIM technology. Various ratios of cryo-ground poly (lactide-co-glycolide) (PLGA) nanofibres (CPN) were incorporated into PNA hydrogel microcapsule.

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