76 research outputs found

    Synthesis of acyclovir as an antiherpes-virus drug

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    A one-pot process for high-yield regioselective synthesis of 9-[(2-hydroxyethoxy) methyl]guanine (acyclovir),  an antiherpetic agent, was achieved from guanine via the steps of reacting of N2,N9 -diprotected guanine with 1-acetyl-2-acetylmethoxy-ethyleneglycol in presence of phosphoric acid or polyphosphoric acid. Total yield of product was 59%. The obtained acyclovir meets the standards in the British Pharmacopoeia 2007 (BP2007). Its activity as inhibitor of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) was evaluated according to the plaque reduction assay method and compared with the standard compound. The synthesized acyclovir showed a similar activity as the control. Keywords: Acyclovir, Herpes simplex virus, Nucleoside, One- pot synthesis

    The Light-to-heat Conversion of Gold Nanoshells and Nanorods in Tissues

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    We perform a set of experiments on photo-heating in tissues containing gold nanoshells (NSs) and nanorods (NRs). The temperature of tissues were measured with different amounts gold NSs and NRs under illumination of a continuous diode laser at 808 nm and power density from 20 to 62 W/cm2^{2}. The temperature of the tissues injected gold nanoparticles increased to $66 \pm  4∘^{\circ}C for 2.1×1082.1 \times 10^{8} NSs and  73± 473\pm  4 ∘^{\circ}C for gold 5.4×1095.4 \times 10^{9} NRs after 10 min exposition at power density 35 W/cm2^{2}. The control tissue without gold nanoparticles demonstrated a significantly lower temperature 40± 440 \pm  4 ∘^{\circ}C in the same time of illumination. The temperature can be reached up to around 100∘^{\circ}C for tissue with both NSs and NRs at 62 W/cm2^{2} inrradiation for 7−107-10 min

    Sub-optimal Deep Pipelined Implementation of MIMO Sphere Detector on FPGA

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    Sphere detector (SD) is an effective signal detection approach for the wireless multiple-input multiple-output (MIMO) system since it can achieve near-optimal performance while reducing significant computational complexity. In this work, we proposed a novel SD architecture that is suitable for implementation on the hardware accelerator. We first perform a statistical analysis to examine the distribution of valid paths in the SD search tree. Using the analysis result, we then proposed an enhanced hybrid SD (EHSD) architecture that achieves quasi-ML performance and high throughput with a reasonable cost in hardware. The fine-grained pipeline designs of 4 × 4 and 8 × 8 MIMO system with 16-QAM modulation delivers throughput of 7.04 Gbps and 14.08 Gbps on the Xilinx Virtex Ultrascale+ FPGA, respectively

    Targeted sequencing from cerebrospinal fluid for rapid identification of drug-resistant tuberculous meningitis

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    Mortality from tuberculous meningitis (TBM) remains around 30%, with most deaths occurring within 2 months of starting treatment. Mortality from drug-resistant strains is higher still, making early detection of drug resistance (DR) essential. Targeted next-generation sequencing (tNGS) produces high read depths, allowing the detection of DR-associated alleles with low frequencies. We applied Deeplex Myc-TB-a tNGS assay-to cerebrospinal fluid (CSF) samples from 72 adults with microbiologically confirmed TBM and compared its genomic drug susceptibility predictions to a composite reference standard of phenotypic susceptibility testing (pDST) and whole genome sequencing, as well as to clinical outcomes. Deeplex detected Mycobacterium tuberculosis complex DNA in 24/72 (33.3%) CSF samples and generated full DR reports for 22/24 (91.7%). The read depth generated by Deeplex correlated with semi-quantitative results from MTB/RIF Xpert. Alleles with <20% frequency were seen at canonical loci associated with first-line DR. Disregarding these low-frequency alleles, Deeplex had 100% concordance with the composite reference standard for all drugs except pyrazinamide and streptomycin. Three patients had positive CSF cultures after 30 days of treatment; reference tests and Deeplex identified isoniazid resistance in two, and Deeplex alone identified low-frequency rifampin resistance alleles in one. Five patients died, of whom one had pDST-identified pyrazinamide resistance. tNGS on CSF can rapidly and accurately detect drug-resistant TBM, but its application is limited to those with higher bacterial loads. In those with lower bacterial burdens, alternative approaches need to be developed for both diagnosis and resistance detection

    Beyond the homestay: women’s participation in rural tourism development in Mekong Delta, Vietnam

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    This study examines the impact of the homestay tourism program in Mekong Delta, Vietnam, on women’s participation and empowerment in rural tourism development. As part of this study, 22 interviews were conducted with homestay owners to explore the benefits and challenges of women’s involvement in this type of tourism. The findings show that homestay tourism program has helped women to generate extra income, strengthen family ties, and increase their social influence while reducing domestic violence. However, cultural expectations and gender roles continue to pose challenges. This study underscores the importance of women’s participation in homestay tourism program and provides suggestions for promoting gender equality and women’s empowerment in tourism development. The study highlights the potential of women’s involvement in creating a sustainable and inclusive tourism industry and calls for further research and action to promote gender equality and women’s rights in tourism. The findings have practical implications for policymakers and practitioners in the tourism sector

    Pollen and seed morphology of cleome species (Cleomaceae) in Vietnam

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    Cleomaceae is a family that includes 18 genera distributed worldwide in tropical and temperate regions. Cleome L. is the largest genus having 207 species, widely distributed in tropical and subtropical regions (POWO 2019). In Vietnam, the genus is represented by four species Cleome rutidosperma DC., C. houtteana Schltdl., C. viscosa L. and C. gynandra L. The present study documents the pollen and seed characteristics of all four species of Cleome in Vietnam, and the data obtained using light microscope and scanning electron microscope are analyzed considering their importance in taxonomic delimitation and understanding their phylogenetic relationship. The results indicated a close relationship between different pollen and aperture types. The striking differences between the pollen shapes among different species of Cleome could be useful in taxonomic and evolutionary studies. Similarly, seed shape and surface characters provided important clues for their delimitation. Based on the pollen and seed morphological characteristics, a taxonomic key has been provided for easy identification of the Cleome species in Vietnam
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