17 research outputs found

    Development of novel bimetallic nickel-cobalt catalysts for hydrodeoxygenation of bio-oil producing a co-feed for a standard refinery unit

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    This work focuses on the development of a novel bimetallic catalyst for hydrodeoxygenation of bio-oil, which is obtained from fast pyrolysis of biomass, to produce a suited co-feed for FCC unit in a refinery. First, the catalysts were tested with phenol as a model compound in both batch autoclave and a continuous flow reactor. Subsequently, the best-performing catalysts (10Ni10Co/HZSM-5) were used for upgrading of a wood-based bio-oil. Finally, upgraded liquid was co-fed with a conventional feed over a commercial catalyst to demonstrate the potential of converting bio-oils into regular fuels

    Perspective on Co-feeding of Phenolic Compounds into Existing Refinery Units

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    Replacement of fossil materials by renewable feedstocks is forced by depletion and environmental concerns but requires new technologies for energy generation or production of chemicals. Co-processing of petroleum with renewable feedstocks in current refinery infrastructure is an attractive option in the mid-term to increase renewable fuel capacity, as the capital investment and operational costs would be marginal. In this chapter, various strategies for admixing of phenolic compounds as renewable feeds into standard refineries are described. Starting from the role of renewable resources (e.g. biomass, lignin and bio-oil) in the current and future energy and chemical community, an overview on the present energy supply situation and the role of phenolic compounds are discussed. Later, a summary on co-feeding of phenolic model compounds with conventional feeds in refineries are illustrated. The co-processing of upgraded bio-oil in refinery units [e.g. fluid catalytic cracking (FCC), hydrotreating] is summarized, showing the potential utilisation of bio-feeds via such processes. Finally, some concluding remarks address the perspectives for further research and development to overcome future challenges

    Establishing protocol for detecting methylation of Ubiquitin carboxyl terminal hydrolase 1 gene’s promoter in nasopharyngeal carcinoma

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    Background: The methylation of Ubiquitin Carboxyl Terminal Hydrolase 1 (UCHL1) gene’s promoter has been reported as the etiological factor of nasopharyngeal tumorigenesis. Purpose: This study is designed to establish a protocol for detecting methylation of UCHL1 gene’s promoter in nasopharyngeal carcinoma (NPC) in a Vietnamese population. Materials and methods: 10 samples of NPC biopsy tissues and 10 samples of non-cancerous swabs were collected from the local hospital. Chloroform/Phenol method and Nested-MSP assays were established to detect methylation of a target gene. Results: The isolated DNA reached purity and high concentration which were confirmed by the method of absorbance measurement at 260nm and 280nm. Additionally, the Nested-MSP products of methylation or unmethylation were analyzed and visualized in the agarose gel with the band of 169bps and 210bps, respectively. By sequencing, it was confirmed that the two sets of primer could distinguish the status of methylation and unmethylation of UCHL1 gene’s promoter. Conclusion: Our data suggested that the current protocol could successfully identify the status of methylation and/or unmethylation of UCHL1 gene’s promoter

    Effect of Silver Nanowire Dimension to Ammonia Adsorption of Graphene-silver Nanowires Hybrid

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    In this report, we study the effect of silver nanowires (AgNws) dimension to electrical properties of rGO/AgNws hybrid. The alteration of these electrical properties leads the difference of ammonia sensibility of the rGO/AgNws hybrid based sensing devices. When the rGO is accompanied by AgNws of different sizes from \sim 500$~\text{nm to } 10\;\mum, the ammonia sensitivity of these hybrids change from 60% to 340% alteration compared with the bare rGO material

    Initial study of single nucleotide polymorphism genotyping of Epstein-barr nuclear antigen 1 (EBNA-1) from Vietnamese nasopharyngeal biopsy samples

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    Background: Epstein-Barr virus nuclear antigen (EBNA1), encoded by EBNA-1 gene, has been shown as one of the most frequently detected protein in Nasopharyngeal carcinoma (NPC), which the most common and highly incident cancer of head and neck cancer in Asian countries. The geographically-associated polymorphisms of EBNA-1 have been observed in East-Southern Asia, including Vietnam. The subtype V-val EBNA-1 has been demonstrated that it may contribute to the oncogenesis of NPC. This current study is initially performed to characterize the variations of EBNA-1 in NPC biopsy samples from Vietnamese patients. Methods: Nested PCR-sequencing was applied to amplify and characterize the C-terminal region of EBNA-1 gene by the designed oligonucleotide primers. Results: 10 NPC biopsy samples were enrolled, as the results, only two patterns of EBNA-1 variations: P-ala and V-val were observed. In addition, of these two subtypes, the frequency of V-val and P-ala were determined counting for 80% (8 of 10 cases) and 20% (2 of 10 cases), respectively. It indicated the V-val subtype preferentially exists in biopsy NPC samples, which collected from Vietnamese patients. Conclusion: We successfully designed the nested PCR-sequencing primer for detection of EBNA-1 variations based on the data collected from previous study. In our initial study, the sub-strain of EBV with V-val subtype of EBNA-1 infects NPC preferentially to those from biopsies of NPC patients. In further study, it is necessary for a larger number of samples and non-cancerous samples in order to confirm the characteristic of EBNA-1 variations, as well as determination of the association V-val subtype with NPC in Vietnamese patients

    Pichia pastoris versus Saccharomyces cerevisiae:a case study on the recombinant production of human granulocyte-macrophage colony-stimulating factor

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    BACKGROUND: Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) is a glycoprotein that has been approved by the FDA for the treatment of neutropenia and leukemia in combination with chemotherapies. Recombinant hGM-CSF is produced industrially using the baker's yeast, Saccharomyces cerevisiae, by large-scale fermentation. The methylotrophic yeast, Pichia pastoris, has emerged as an alternative host cell system due to its shorter and less immunogenic glycosylation pattern together with higher cell density growth and higher secreted protein yield than S. cerevisiae. In this study, we compared the pipeline from gene to recombinant protein in these two yeasts. RESULTS: Codon optimization in silico for both yeast species showed no difference in frequent codon usage. However, rhGM-CSF expressed from S. cerevisiae BY4742 showed a significant discrepancy in molecular weight from those of P. pastoris X33. Analysis showed purified rhGM-CSF species with molecular weights ranging from 30 to more than 60 kDa. Fed-batch fermentation over 72 h showed that rhGM-CSF was more highly secreted from P. pastoris than S. cerevisiae (285 and 64 mg total secreted protein/L, respectively). Ion exchange chromatography gave higher purity and recovery than hydrophobic interaction chromatography. Purified rhGM-CSF from P. pastoris was 327 times more potent than rhGM-CSF from S. cerevisiae in terms of proliferative stimulating capacity on the hGM-CSF-dependent cell line, TF-1. CONCLUSION: Our data support a view that the methylotrophic yeast P. pastoris is an effective recombinant host for heterologous rhGM-CSF production

    TextANIMAR: Text-based 3D Animal Fine-Grained Retrieval

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    3D object retrieval is an important yet challenging task, which has drawn more and more attention in recent years. While existing approaches have made strides in addressing this issue, they are often limited to restricted settings such as image and sketch queries, which are often unfriendly interactions for common users. In order to overcome these limitations, this paper presents a novel SHREC challenge track focusing on text-based fine-grained retrieval of 3D animal models. Unlike previous SHREC challenge tracks, the proposed task is considerably more challenging, requiring participants to develop innovative approaches to tackle the problem of text-based retrieval. Despite the increased difficulty, we believe that this task has the potential to drive useful applications in practice and facilitate more intuitive interactions with 3D objects. Five groups participated in our competition, submitting a total of 114 runs. While the results obtained in our competition are satisfactory, we note that the challenges presented by this task are far from being fully solved. As such, we provide insights into potential areas for future research and improvements. We believe that we can help push the boundaries of 3D object retrieval and facilitate more user-friendly interactions via vision-language technologies.Comment: arXiv admin note: text overlap with arXiv:2304.0573

    The solid-phase partitioning of arsenic in unconsolidated sediments of the Mekong Delta, Vietnam and its modes of release under various conditions

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    Arsenic (As) contamination of the groundwater in the Mekong Delta is a serious problem affecting millions of people who rely on this important resource for drinking and agriculture. In this study, borehole cores up to a depth of 40 m were collected in the Vietnamese-side of the delta, and the solid-phase partitioning of As with depth was investigated to understand the factors and processes controlling the release of this toxic element under oxic, acidic and reducing conditions. The results showed that in most of the sediments, substantial amounts of As are partitioned with exchangeable phases that are easily released into solution. Two borehole cores obtained between the Hau and Tien Rivers also had significantly high As partitioned with organic/sulfide phases and one of these cores had abundant As-bearing pyrite in 1-m thick peat layers. Leaching experiments in deionized (DI) water coupled with principal component analysis suggest that As release was controlled by sorption-desorption reactions with clays/phyllosilicates (i.e., kaolinite, muscovite and clinochlore), proton-promoted dissolution of iron-oxyhydroxides, and oxidation of pyrite/organic matter. The mobility of As was further promoted under acidic conditions in the presence of chloride (Cl-), which suggests that seasonal drying/flooding episodes generating acid sulfate soils, as well as salt water intrusion due to excessive groundwater abstraction may exacerbate this problem in the future
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