Preliminary study of doxycycline adsorption from aqueous solution on alkaline modified biochar derived from banana peel

Van-Truc Nguyen,Thanh-Binh Nguyen,Thi-Dieu-Hien Vo,Nguyen Duy Dat,Thi-Kim Quyen Vo,Xuan Cuong Nguyen,Viet-Cuong Dinh,Thi-Ngoc-Chau Le,Thi-Giang-Huong Duong,Manh-Ha Bui,Xuan-Thanh Bui 대한환경공학회 2023 Environmental Engineering Research Vol.29 No.3

This study explores the adsorption of doxycycline (DOX) from aqueous solutions onto biochar derived from banana peel, which was prepared using a potassium hydroxide activation method (KOH-BPB). The biochar properties were characterized based on morphology, surface area (SBET of 710.241 ㎡ g<SUP>−1</SUP>), functional groups, and surface charge (pHPZC = 7.7). Parameters, including initial pH, DOX concentration, and ionic strength, that influenced the DOX adsorption capacity of KOH-BPB were examined. Adsorption equilibrium of DOX on KOH-BPB was assessed through four isothermal models: the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models. The obtained data were most compatible with the Langmuir model (R² = 0.9879). KOH-BPB has a maximum DOX absorption capacity of 121.95 mg g<SUP>-1</SUP> which exceeds that of many comparable absorbents. The maximum DOX removal was 96.7% at pH 6, a DOX concentration of 20 mg L<SUP>-1</SUP>, and a KOH-BPB dose of 1.0g L<SUP>-1</SUP>. These findings reveal that biochar from banana peel effectively removes antibiotic residues from water. This study provides a potential, low-cost, and environmentally friendly adsorbent.

Drynaria bonii spore culture: optimization of culture conditions and analysis of gametophyte and sporophyte development

Quyen Van Nguyen,Hang Thi Khuat,Yen‑Ngoc Thi Nguyen,Dung Thi Vu,Thu‑Ha Bui,부경환 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.5

Drynaria bonii H. Christ is a medicinal plant that has traditionally been used for the treatment of chronic diseases and tuberculosis. However, D. bonii has not yet been cultivated or propagated. In this study, we optimized the conditions for the spore culture of D. bonii to produce sporophytes. First, we evaluated the efects of various factors, such as temperature, light intensity, potting material, and pH, on spore germination and early gametophyte development. Under optimal culture conditions, 95–99% of the spores germinated within 2 weeks of culture. Next, based on these results, we established a culture system for gametophyte development and sporophyte production. Mature gametophytes frst appeared 5 months post-germination (mpg), and at 12 mpg, the rate of production of heart-shaped gametophytes reached 56.6%. Sporophytes at the early frst-leaf stage frst appeared at 6 mpg, and at 12 mpg, the rate of formation of sporophytes reached 15.4%. Interestingly, 6.3% of all gametophytes produced multiple sporophytes. Additionally, 42–62% of the gametophytes also produced multiple secondary gametophytes, indicating a high potential of D. bonii gametophytes to generate new gametophytes and, subsequently, sporophytes. When transferred to new trays or pots, sporophytes grew well and showed 100% survival. Overall, we conclude that this spore culture system can be successfully used for the propagation of D. bonii sporophytes.

Various Factors in the Acquisition of English Tough-Construction by Vietnamese EFL Learners

Nguyen Thi Quyen 한국응용언어학회 2018 응용 언어학 Vol.34 No.4

This paper reviews the L2 acquisition of English tough-construction and reports some preliminary findings on how Vietnamese L2 learners of English process English tough-construction. Sentences involving tough predicate as in John is tough/difficult to please has been observed to cause great difficulty for L1 children and L2 learners. In an attempt to characterize L2 learners’ representation of English tough-construction, this research employed a forced choice sentence continuation task and an acceptability judgment task to probe into L2 learners’ implicit and explicit knowledge of such syntactically complex structure. The study yielded some significant contributions to the L2 acquisition literature. On the one hand, this study is among the few that explore the effect of several linguistic factors on the L2 acquisition of English TCs and incorporate statistical tests into analysis, which apparently makes the conclusion of the paper more reliable. On the other hand, the findings of this study cast some doubt on an important hypothesis about L2 acquisition order of syntactically complex structures, which would encourage investigation of the related phenomenon in L2 acquisition research.

Chemical Constituents from the Aerial Parts of Artemisia capillaris Thunb. and Their Anti-allergic and Anti-inflammatory Effects

Thi Thu Nguyen,Thi Oanh Vu,Thao Quyen Cao,민병선,김정아 한국생약학회 2020 Natural Product Sciences Vol.26 No.1

Artemisia capillaris Thunb. (Compositae) is a traditional medicinal plant with various pharmacological activities. To elucidate new anti-allergic and anti-inflammatory constituents, the aerial parts of A. capillaries were investigated to afford a new compound, (6E,8E)-6-methylundeca-6,8-diene-2,5,10-trione (17) together with 19 known compounds (1 - 16, 18 - 20). The structures of these compounds were determined by extensive spectroscopic analyses including 1D, 2D NMR, HREIMS, and optical rotation [α]D. The absolute configuration of compound 2 was determined to be S form for the first time. All isolates (1 - 20) were tested their inhibitory effects on interleukin 2 (IL-2) expression in T cells and NO production in lipopolysaccharide (LPS)-stimulated RAW246.7. Among them, compounds 10, 11, 19, and 20 reduced IL-2 expression in a dose-dependent manner. In addition, compound 10 also inhibited NO production with an IC50 value of 37.3 ± 0.4 μM.

Arabidopsis Raf-Like Kinase Raf10 Is a Regulatory Component of Core ABA Signaling

Nguyen, Quy Thi Cam,Lee, Sun-ji,Choi, Seo-wha,Na, Yeon-ju,Song, Mi-ran,Hoang, Quyen Thi Ngoc,Sim, Seo Young,Kim, Min-Sik,Kim, Jeong-Il,Soh, Moon-Soo,Kim, Soo Young Korean Society for Molecular and Cellular Biology 2019 Molecules and cells Vol.42 No.9

Abscisic acid (ABA) is a phytohormone essential for seed development and seedling growth under unfavorable environmental conditions. The signaling pathway leading to ABA response has been established, but relatively little is known about the functional regulation of the constituent signaling components. Here, we present several lines of evidence that Arabidopsis Raf-like kinase Raf10 modulates the core ABA signaling downstream of signal perception step. In particular, Raf10 phosphorylates subclass III SnRK2s (SnRK2.2, SnRK2.3, and SnRK2.6), which are key positive regulators, and our study focused on SnRK2.3 indicates that Raf10 enhances its kinase activity and may facilitate its release from negative regulators. Raf10 also phosphorylates transcription factors (ABI5, ABF2, and ABI3) critical for ABA-regulted gene expression. Furthermore, Raf10 was found to be essential for the in vivo functions of SnRK2s and ABI5. Collectively, our data demonstrate that Raf10 is a novel regulatory component of core ABA signaling.

Impact of Processing Various Textual Genres on the Incidental Acquisition and Retention of L2 Vocabulary

Nguyen Thi Quyen 한국영어교육학회 2023 ENGLISH TEACHING(영어교육) Vol.78 No.2

This study investigated the effects of processing three types of texts, namely expository texts, narrative texts, and a combination of both known as twin texts, on incidental vocabulary acquisition and retention in L2 learners. College freshmen (N = 109), who were lower to upper intermediate learners of English, were assigned into a control group and three experimental groups representing different reading conditions. Over a period of seven weeks, the experimental groups engaged in two reading sessions to read their assigned texts accompanied by output tasks and input enhancement. The participants’ receptive and productive vocabulary gains were measured with an immediate posttest and a delayed posttest to assess retention. Results revealed significant impacts of text genres on L2 incidental vocabulary learning and retention. Processing twin texts and expository texts yielded significantly greater vocabulary gains than processing narrative texts alone. These effects might be due to different processing mechanisms required for texts structured in distinct ways. Expository texts are informative and explanatory in nature, providing explicit and contextually rich information for word comprehension and retention.

Factors Affecting Pronoun Resolution by Vietnamese EFL Learners

Thi Quyen Nguyen 한국응용언어학회 2017 응용 언어학 Vol.33 No.1

This study examined the effects of verb semantics, discourse unit and discourse coherence relations pronoun interpretations by Vietnamese EFL learners. Using a sentence continuation test with 32 Vietnamese EFL learners, three significant insights contributed to the existing L2 literature. Firstly, Vietnamese EFL learners were highly sensitive to semantic cues and discourse coherence when resolving pronouns. Secondly, learner preferences for in within-sentence and between-sentence contexts’ pronoun antecedents were mostly indistinguishable, suggesting that discourse unit had a negligible impact on anaphora resolution processes. Finally, verb semantics and coherence relations exhibited a dynamic interaction effect on L2 pronoun resolution Verb types varied sharply when co-occurring with different types of coherence relations.

Using Pacemaker to achieve VM Cluster High Availability for NFV

Nguyen Thi Le Quyen,Hwa Sung Kim 한국통신학회 2016 한국통신학회 학술대회논문집 Vol.2016 No.6

Production of transgenic soybean plants carrying modified cry1Ac gene

Quyen Nguyen Thi,Jung Hun Pak,Mi-Jin Kim,Hye Jeong Kim,Ha Neui Hong,Yeon Ho Je,Young Soo Chung 한국육종학회 2012 한국육종학회 심포지엄 Vol.2012 No.07

Cry1Ac protein is known as one of toxin crystal proteins synthesized from Bacillus thuringenesis that plays a critical role for the insect resistance. Recently, cry1Ac genes have introduced into many plants in general and soybean as well. However, the gene expression of cry1Ac genes in transgenic plants remains low that need to be improved. Several mutations we reintroduced into the cry1Ac genes in order to enhance the insecticidal effect. In this study, the cry1Ac with mutant #2, #11 and #16 were transformed into Kwangan, a Korean soybean variety by using the “half-seed” method. The plant lets carrying modified cry1Ac genes were primarily selected on media containing Phosphinothricine (PPT), a bar selective agent and Basta leaf painting. Then, the presence of introduced genes in T0 plants and the gene expression were investigated by PCR, RT-PCR and Real-time PCR. PCR and RT-PCR analysis showed expression of bar and cry1Ac genes from tested transgenic soybean plants. The number of copy of bar gene ranged from 1 to 3 by Real-time PCR analysis. These results provided a fundamental back ground for our further experiments: Confirmation of the gene expression by Southern blot and identification of the function of modified cry1Ac by insect bioessays.

Barriers to Derivative Accounting Disclosure: The Case of Vietnamese Firms

NGUYEN, Hanh Thi Hong,TRAN, Ngoc Minh,NGUYEN, Quyen Le Hoang Thuy To Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.10

This paper explores the barriers to derivative accounting disclosures in Vietnamese companies and ranks their relative importance for effective and efficient remedies. The Delphi technique was applied to get agreement of panel of experts on the measurement of factors hindering disclosure. Unstructured questionnaires were first sent to twelve experts who had both practical experience and academic knowledge in the field to get ideas on the obstructions to derivatives disclosure. The structured questionnaire was designed to get their agreement on barriers to derivative accounting disclosures. The data analysis with mean, median, mode, standard deviation, and quartile has been implemented to ensure the unanimity. Market-related factors, legislation, accountants' attributes, managers' attributes, information technology and communication, and on-site training were the six major obstacles agreed upon by the experts during their in-depth interviews. Then, these factors were ranked by applying the analytical hierarchy process (AHP). The findings confirmed the priority of information technology and communication, which held the greatest weight. Legislation ranked second, followed by market-related factors and on-site training, which explained the impediments to derivatives disclosure. Managers' and accountants' attributes had the least contribution to the barriers to derivative disclosures. The results have important implications for actions to enhance corporate derivative disclosures in Vietnam.