bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological activities of phenolic compounds extracted from some plant species from east Kalimantan province, Indonesia
Authors:   , Mariani Franxisca
Published: September 2023

Ten medicinal plants used in this study are based on the experience of Dayak tribes. The scientific information about these plants are still limited, therefore, the objective of the present study was to analyze their phenolic content and biological activities. A selected species was subjected to successive extraction and compound isolation. The total phenolic content and total antioxidant capacity were analyzed by using Folin-Ciocalteu reagent and the phosphomolybdenum method, respectively. DPPH and ABTS assays were used for analyzing antioxidant activities. The antibacterial activity was performed against six bacterial strains by agar well diffusion and microdilution methods. The anti-tyrosinase activity used L-tyrosine substrate, whereas the antidiabetic assay used sucrose and maltose substrates. Human breast cancer cells (MDA-MB-231) were used for the anticancer activity test, while human keratinocyte cells (HaCaT) were used for the cytotoxicity effect and wound healing activity. Silica gel column chromatography and 1H NMR were performed for compound isolation. The results showed that Rhodomyrtus tomentosa had broad-bioactivities, Elaeocarpus submonoceras could be applied as antioxidant, anti-tyrosinase, and antidiabetic agents, while Entada phaseoloides as antioxidant, anti-tyrosinase, and anticancer agents. Goniothalamus macrophyllus and Pogostemon cablin could be used as antioxidant and anticancer agents. Lastly, Helicia robusta and Litsea elliptica is applicable as antioxidant, antidiabetic, and anticancer agents. The gallic acid was successfully isolated from E. submonoceras leaves extract. These findings suggest that these plants are potential as natural medicine and health supplement.
Warehouse Layout Design For A Metal Conduit Manufacturer
Authors:   , Pattarakulprasit Atiyot
Published: September 2023

Nowadays, warehouse layout problems become a common problem for every organization, especially in conduit businesses. Finding an appropriate space to store the products, transporting the products in and out of the warehouse or even an effective way of using material-handling, for example, an overhead crane, is the most relevant topics that can cause a lot of costs and time for the organizations. To resolve these problems, the simulation is built to see the consequences of altering the position of conduit in the warehouse. For each layout design in the simulation is built based on the information provided by the conduit producer organization in Thailand. The results of the simulation are the layouts that provide the less distance involved and time usage for transporting the conduits in and out of the warehouse which leads directly to reduce the costs in the organization.
Inbound Logistics Management for a PVC Resin Manufacturer
Authors:   , Ruengrapeepun Thunlapas
Published: September 2023

The main objective of this research is to enhance logistics operation of a Thai PVC manufacturer located in Rayong, where we will focus more on the domestic part involving with three different PVC products, that is, Palletized PVC, Flexible-bag PVC, and Tank car PVC. Based on the historical data collected in 2017, over 90 percent of the complaints was identified as delivery delays caused by comparatively long non-value added activities within the inbound logistics process, such as waiting in weighting-in process and over processing steps in delivery paper generation. In order to address these issues, truck scheduling and throughput time improvement initiatives had been suggested, each of which was assessed by a simulation software named Arena. Based on these initiatives, the company could potentially reduce the throughput time, i.e. the time from which a truck arrived till its departure from 180 minutes to 120 minutes, or approximated one-third of the current practice.
Improving EFL undergraduate students’ English speaking skill through dynamic assessment
Authors:   , Siwathaworn Prathana
Published: September 2023

This study focuses on the application of dynamic assessment (DA) for pedagogical purposes. It is aimed at investigating how the students’ English speaking skill could be improved through DA, which is grounded in Vygotsky’s zone of proximal development (ZPD). The objectives of this study were (1) to investigate to what extent DA assists EFL undergraduate students to improve their English speaking skill, (2) to explore the students’ perceived self-efficacy in their English speaking skill through DA, and (3) to examine the students’ attitudes toward DA. The participants of the study were 10 university students who studied in an EFL classroom of Foundation English I (ENG 101). Both qualitative and quantitative research instruments were employed in this study. As for the qualitative instruments, the participants’ verbal report, semi-structured interviews, and diaries were adopted. The quantitative instruments employed in this study were the three tests (pretest, posttest, and delayed posttest), a self-efficacy questionnaire, and an attitude questionnaire. The results of the study revealed that through the test-train-retest design, DA improved the students’ English speaking skills and their perceived self-efficacy toward English speaking skills. The data from qualitative instruments showed that the participants gained meaningful learning experiences through DA procedures. All participants expressed positive attitudes toward DA. The results of this study indicated that DA encouraged the students to construct a sense of ownership in their own learning and to become actively engaged in the test tasks. Thus, this study has shed light on the possible application of DA for a remedial classroom in an EFL context.
Conversion of waste chicken fat to liquid fuel on coal fly ash catalyst by catalytic cracking
Authors:   , Suchamalawong Phorndranrat
Published: September 2023

In this research work, a study on the catalytic cracking of waste chicken fat (WCF) on fly ash to liquid fuels and using 2k factorial design to determine the influence of parameters on liquid yield, naphtha and diesel content was investigated. The research was divided into 2 parts. First, the experiment was carried out in a batch lab scale reactor of 70 mL. The objectives are to determine the influence of parameters that affected the %yield of liquid product naphtha and diesel–liked fuels at the operating conditions of temperature range of 420 - 460 ˚C, reaction time 45-75 minutes, initial hydrogen pressure of 1-5 bar and coal fly ash loading of 1-5 %wt. The liquid product was collected and analyzed using simulated distillation gas chromatography according to ASTM2887. Data of experiments were analyzed by design-expert program, the results showed that the optimal condition was operated at a temperature of 445 ˚C, the reaction time of 45 minutes, the initial pressure of hydrogen 1 bar, coal fly ash loading of 1%wt, which obtained the highest liquid yield of 76.76 %wt., whereas the liquid product consisted of 21.50 %wt. naphtha and 31.00 %wt. diesel. The liquid product has the heating value of 42.92 MJkg-1 and the acid value is 13.51 mgKOHg-1. The kinetics study was examined due to the conversion change of long residue with the reaction time. The results indicated the second order with respect to long residue, the activation energy (Ea) 85.97 kJmol-1and frequency factor (k0) 1.01×103 s-1. The experiment in the second part was focused on the production of liquid fuel in 3 L continuous reactor. The ranges of study variables were as follows: temperature of 420-460 ˚C, flow rate of waste chicken fat of 3-9 mL/min, N2 gas flow rate of 50-150 mL/min and amount of catalyst 30-60 % (occupied by reactor volume). From design-expert program, it was found that the optimal condition of continuous reactor were temperature 460 ˚C, flow rate of waste chicken fat 9 mL/min, N2 gas flow rate 50 mL/min and amount of catalyst 60 % of reactor volume, gave the highest yield of liquid, naphtha and diesel were 76.76, 21.62 and 41.65 %wt, respectively. The coal fly ash catalyst was determined the catalyst efficiency, it was found that fly ash activity is stable during 7 hours and after decreasing because of some of CaO was converted to Ca(OH)2. The obtained physicochemical of liquid product had a heating value of 43.39 MJkg-1, acid value of 3.82 mgKOHg-1
Doctoral in creative music research : the musical dialect in modern conventional idiom of the piano concertos
Authors:   , Zereu Paulo
Published: September 2023

This research aims to explore the musical dialect within the conventional idiom as well as the interpretational approach and analytical overview of the selected Piano Concertos. The three prominent and significant Piano Concertos were chosen as followed: 1) Concerto in E-flat major for Two Pianos and Orchestra, KV. 365 by Wolfgang Amadeus Mozart (1756-1791), 2) Concerto in C major for Piano, Violin, Cello, and Orchestra, Op.56 by Ludwig van Beethoven (1770-1827), and 3) Concerto for Two Pianos and Orchestra in D minor by Francis Poulenc (1899-1963). The research also presented the innovative revolutionary of the pianistic and interpretational challenges of the performing techniques included a stylistically authentic and musically dramatic context.

     In additional to making the Mozart’s concerto to be a well-crafted presentation, the theoretically edited cadenza has been perfectly designed to this dissertation. The highlight of the research was the three international and national performances accompanied by the world renowned pianist such as Martin Widmaier and highly established orchestras, the Bulgarian New Symphony Orchestra and Royal Thai Air Force Symphony Orchestra.
Study of megakaryocytes and platelets in bernard soulier syndrome using patient induced pluripotent stem cells
Authors:   , Mekchay Ponthip
Published: September 2023

Bernard-Soulier syndrome (BSS) is a hereditary macrothrombocytopenia caused by defects in GPIb-IX-V complex. The mechanism of large platelet formation remains unclear. Currently, megakaryocytes (MKs) can be generated from induced pluripotent stem cells (iPSCs) to study platelet production under pharmacologic or genetic manipulations. In this study, we generated iPSC lines from 2 patients with mutations in different genes (GP1BA and GP1BB: termed BSS-A and BSS-B, respectively), iPSCs were then differentiated into MKs and platelets. In vitro iPSCs-derived platelets were stained for circumferential tubulin and measured the diameters (N = 500 per condition). BSS-iPSCs produced abnormal proplatelets with thick shafts and tips, as well as larger platelets with mean diameters ± SD of 4.34±0.043, 3.88±0.045 and 2.61±0.025 µm from BSS-A, BSS-B and normal iPSCs, respectively (p<0.001). Overexpression of the GPIb in BSS-A-iPSCs using a lentiviral vector containing GP1BA gene improved proplatelet structures and decreased platelet sizes (3.184±0.078 µm [corrected BSS-A], 4.453±0.096 µm [BSS-A], p<0.001) however the transgene was not expressed in BSS-B-iPSCs.  Subsequently, IL-1α and blebbistatin were used to explore BSS pathogenesis. The IL-1α-induced MK rupture yielded larger platelets from normal iPSCs and there was no further increase in sizes of BSS-iPSCs-derived platelets. Furthermore, adding blebbistatin, a myosin II inhibitor, reduced the platelet sizes derived from BSS-iPSCs (3.20±0.035 vs. 4.38±0.046 µm [BSS-A], 3.09±0.033 vs. 4.48±0.047 µm [BSS-B], p<0.001). Combining of blebbistatin and IL-1 decreased the mean sizes of BSS-iPSC-derived platelets (4.43±0.110 vs. 3.34±0.090 µm [BSS-A], 4.60±0.103 vs. 3.20±0.089 µm [BSS-B]). Moreover, we constructed BSS-iPSC tubulin-GFP reporter lines which will be a useful tool for future studies of iPSC disease models. In conclusion, BSS-iPSCs could be used as a model for giant platelet disorders. Our data suggest that GPIb-IX-V is not necessary for IL-1α induced platelet production, but likely involved in the proplatelet formation which is related to a myosin function.
Application of Konjac glucomannan to encapsulate and stabilize the curcumin in milk system
Authors:   , Hayuningtyas Afwa
Published: September 2023

This study investigated the influence of different concentration of konjac glucomannan (KGM) (0, 0.1, 0.2, 0.3 % (w/v)) on the stability of curcumin emulsion in milk system containing 10%, 20%, and 30% (v/v) oil volume fraction. The data of creaming index, curcumin concentration, apparent viscosity, and color were obtained to investigate the stability of the system. Emulsions that reached the physical stability until 14 days of storage at 4ᵒC were subjected to further analysis including antioxidant, particle size, zeta potential, and bioaccessibility by the simulated gastrointestinal tract (GIT). The result suggested that increasing KGM concentration significantly increased the viscosity of the water phase, following by increasing the viscosity of the emulsion system. The viscosity result is related to the increase of creaming stability when KGM concentration is increased from 0.1% to 0.2% w/v KGM containing higher oil volume fraction. However, emulsions containing 0.3% KGM showed poor creaming stability due to depletion flocculation. The result showed that increasing KGM concentration had no significant impact on the concentration of curcumin and had no significant impact on the yellowness (b* value) in the final emulsion. However, the increased oil phase volume fraction significantly increased the curcumin concentration and b* value of emulsions due to the increasing of curcumin content that added together with oil into the system. The emulsions containing 20% v/v oil significantly showed a better loading capacity compared to 10% v/v and 30% v/v oil, suggesting that there were a sufficient concentration of native emulsifier (milk protein) and KGM to cover and stabilize oil droplet containing curcumin in 20% v/v oil. DPPH and FRAP assay showed the antioxidant activity of emulsion remained stable over 14 days of storage at 4ᵒC and was related to the concentration of curcumin in the system. However, there is no significant effect of KGM concentration on the antioxidant activity. Addition of KGM can potentially slower the release of curcumin from the emulsion droplet during the upper part of GIT. The result indicated that introducing KGM to the water phase of emulsions is feasible to achieve a controlled release of curcumin from emulsions. Finding in this study denoted that structuring water phase with the low concentration of KGM could be possible to design curcumin in milk system containing high oil-phase fraction with potential emulsion stability and control release properties.
Influences Of Geologic Conditions And Anthropogenic Activities On Changes Of Geomorphology And Sediment Load Characteristics Of The Ping And Chao Phraya Rivers
Authors:   , Chaiwongsaen Nikhom
Published: September 2023

The Chao Phraya River flows into the largest river basin of Thailand. The Ping River is one of its the major upstream branches flowing down slope southwardly, joining the Chao Phraya River in the central plain and ends at the Gulf of Thailand. The sand-choked is extensively observed and the flood overflow occurs frequently and rapidly at the Lower Ping River. In contrary, the Chao Phraya River, the erosion of river bank and shoreline around the river mouth has been spatially increasing in place. The Landsat imageries taken in 1987, 1997, 2007 and 2017 were used to analyze geomorphological changes of both rivers. Results show that the total emerged sand bar area in the Lower Ping River had increased up to 28.8 km2. The excessive trapped bed sediments deposition along the upper reaches is responsible for the shallower of river embankment leading to rapid overflow during flooding. In contrary, at the Chao Phraya River mouth, a total of 18.8 km2 of the coastal area had been eroded. Along the Lower Ping River, the bedload transport rates significantly decline toward the downstream. Most of bedload has been trapped above Bhumibol Dam. Then the bedload has been resupplied again by tributaries downstream and trapped within the succession of weirs. The combination of high supplied bedload from tributaries and low and suppressed discharge by dams and weirs accelerates growth rate of sandbars. However, within the succession of weirs severe bank collapses can occur locally as rapid growth of sandbars abruptly change the direction and increase flow velocity. Both anthropologic, and geologic factors play important roles in changing hydrosedimentary conditions of the Lower Ping River. The anthropologic factors include, river regulations, high deforestation rate, and intense in-channel sand mining. Whereas geologic factors are the underlying lithology and degree of weathering and erosion. The high rate of bedload budget links to highly weathered granite outcrops in the mountainous regions. Using Digital Shoreline Analysis System (DSAS) software and Satellite images from Google Earth can locates significant changes of river accretion and erosion along the riverbanks. The Integrated GPR-Electrical Resistivity Survey (IGRS) technique has revealed the internal structure and determined the thickness of a sandbar on the Lower Ping River. The sandbar thickness detected from this study is 10-12 m. There are several possibility implications from this study involving construction of weir, in-channel sand mining, reservoir sedimentation and coastal erosion management.
Mineral inclusions in ruby and sapphire from Bo Welu and Bo Rai deposits, eastern Thailand
Authors:   , Promwongnan Supparat
Published: September 2023

Corundum deposits located in several places around the world which appear to have different genesis models. The origins of corundum can be distinguished by mineral inclusions. In this study, most of the rough gem corundum from Bo Rai deposit, Trat Province, and Bo Welu deposit, Chanthaburi Province, in Eastern Thailand show etched or dissolved surfaces that were resulted from dissolution by hot basaltic magma during transportation to the surface. Moreover, these gem corundums also show absorption spectral characteristics related to trace elements which typical for corundum from this area. Corundums from Bo Rai deposit in Trat Province, and from Bo Welu deposit in Chanthaburi Province were collected for this study. Various mineral inclusions in ruby were discovered, particularly high Al diopside (fassaite pyroxene), pyropic garnet, plagioclase feldspar, sillimanite, spinel, and sulphide are also observed in Bo Welu ruby similar to Bo Rai ruby. However, anatase inclusion is only identified in Bo Rai. On the other hand, sapphirine, quartz, nepheline, and anhydrite are only identified as inclusions in Bo Welu ruby. Mineral inclusions in sapphire from Bo Welu deposit are zircon, alkali feldspar, sulphide, monazite, columbite. Based on chemical composition of mineral inclusion, rubies from both Bo Rai and Bo Welu deposits may have originally formed within a similar environment, mafic granulites rocks, probably within lower crust to upper mantle. Blue and bluish green sapphires from Welu deposit may have crystallized from a highly evolved, alkali-rich and silica-poor magma at a shallower level in the lithosphere. Although, the formation of ruby located at deeper levels (upper mantle) than the sapphire (crust/upper mantle), some similar mineral inclusions in both ruby and sapphire may indicate co-crystallization between ruby and sapphire in some places.
Crude oil removal by Sphingobium sp. MO2-4 and Bacillus megaterium TL01-2 immobilized on aquaporous gel
Authors:   , Rungsihiranrut Adisan
Published: September 2023

Petroleum products are the major energy sources that drive global economy. The exploration and exploitation of crude petroleum oil increase the potential risk for oil spills in marine ecosystem. In this work, two non-pathogenic sponge-associated bacteria were developed as immobilized bacterial co-culture for crude oil removal from seawater. Two bacteria were Spingobium sp. MO2-4 that could degrade crude oil, diesel oil, and fuel oil, and Bacillus megaterium TL01-2 that could degrade crude oil, possessed high cell surface hydrophobicity, could tolerate heavy metal, and was able to form biofilm.. The modified polyurethane foam, aquaporous gel (AQ), was used as carrier for the bacteria. The crude oil removal from actual seawater by immobilized bacteria was carried out in three groups based on immobilization process. With the initial crude oil concentration of 2,000 mg/L, the result showed that immobilization of the bacteria as co-culture using 2:1 (MO2-4:TL01-2) inoculum volume ratio yielded the best result with 1,757 mg/L of crude oil removed and 1,427 mg/L was degraded within 7 days, thus the ratio was chosen for further use in the semi-continuous system and wave simulator tank. The semi-continuous system study revealed the better performance of immobilized bacteria over the free cell; in addition, the immobilized bacteria survivability throughout the experiment was confirmed by viable plate count and Scanning Electron Microscope (SEM). The wave simulator tank containing 20 L seawater was used to simulate the removal of oil spill by immobilized bacteria in marine environment. The result revealed that the immobilized bacteria could remove more than 90% of crude oil within 7 days. Furthermore, when compared the amount of crude oil accumulated in AQs from the immobilized bacteria treatment and sterilized AQs treatment at the end of experiment; the result showed that the immobilized bacteria could degrade 72% of the absorbed crude oil. Accordingly, these results suggested that the immobilized bacteria is a promising tool for bioremediation of crude oil-contaminated marine environment.
Formulation of oil dispersants by mixing lipopeptide biosurfactant and non-ionic surfactants
Authors:   , Nawavimarn Parisarin
Published: September 2023

Marine oil spill can cause various harmful impacts to the environment. To solve this problem, dispersant is usually applied to enhance petroleum remediation in seawater. The commercial dispersants mostly contain surfactant and solvent that can be toxic to marine lives. This study aimed to formulate solvent-free biosurfactant-based dispersants by mixing lipopeptides from Bacillus subtilis GY19  with fatty alcohol ethoxylate (Dehydol LS7TH), a low toxicity nonionic surfactant. Hydrophilic-lipophilic deviation (HLD) concept was applied. The fractions of lipopeptide and dehydol LS7TH were determined based on the equivalent alkane carbon number (EACN) of hydrocarbons under seawater salinity (34ppt). The molar fractions of lipoppeptide were corresponded with the hydrophobicity of hydrocarbons in the system. The lipopeptide-dehydol LS7TH formulations expressed microemulsion type III especially when the fractions of each surfactant were calculated from the HLD equation for ionic surfactant. The formulation consisted of 6.6% lipopeptide, 11.9% dehydol LS7 and 3.4% NaCl had the highest dispersion effectiveness (DE) with Bongkot light crude oil (BKC) and two fuel oils i.e. fuel A and fuel C, which was better than the commercial dispersants i.e. slickgone and superdispersant-25. To apply in the oil spill events, the dispersant to oil ratio (DOR) was determined by response surface plot from Box-Behnken design analysis. This approach could be applied to various petroleum types under wide range of salinity conditions. The lipopeptide-dehydol LS7TH formulation was considered environmental friendly since it had low toxicity with petroleum-degrading bacteria and also promoted the plant growth. In conclusion, this study recommended to use HLD equation for ionic surfactant to formulate the lipopeptide-dehydol LS7TH dispersant. The suitable formulation had high oil dispersibility, while the cost was reduced due to the lower amount of lipopeptide biosurfactant comparing to the previous report.
Effects of surfactants and thickness of carbon nanotube film on conductive property for touch screen
Authors:   , Channarong Thimaporn
Published: September 2023

Conductive transparent film technology has been developed extensively for electronic industry such as touch panel and so on. In this study, single-wall carbon nanotubes (SWCNTs) was chosen to disperse in acrylic resin and homogenized by surfactant. The dispersion of SWNCT is one of the key factors that strongly influences the properties of these products. Thus Hydrocarbon and Silicone surfactant types were compared. The wire-bar coating technique was used to produce a conductive film PET base. Our objectives were to study the effects of surfactants and thickness of SWCNT film on conductivity and transparency. Surfactant concentration was varied 0.1 – 2.0 % w/w. Film formation samples were done by using wire K-bar rods varied the thickness using single and multi-coating method. Transparency and sheet resistance were analyzed. Results showed that the varying surfactant concentration and coating thickness did slightly affect obviously the change of transmittance of conductive films and sheet resistance varied between 10⁴ – 10⁵ Ω/square for both surfactants. While sheet resistance declined relevant to the increase of SWCNT thickness and the amount of surfactants. Results showed Silicone surfactant gave better results than Hydrocarbon surfactant, the optimum sheet resistance was at 8.91x10² Ω/square with 87% transmittance (including PET film) and 2.63x10³ Ω/square with 86% transmittance by using 2.0% of silicone and hydrocarbon surfactant respectively with the film thickness of 250 microns.
Forecasting International Tourist Arrivals from Major Countries to Thailand
Authors:   , Hwandee Ontheera
Published: September 2023

Tourism industry is one of industries that are very important for Thai economy. In order to achieve effective marketing and resource planning, accurate forecasting of tourist arrivals from major countries to Thailand is necessary for Thai tourism industry. In this paper, various forecasting models are explored to forecast monthly tourist arrivals from China, Malaysia, Korea, Japan, Russia, UK and US. The proposed models include both time series models, i.e., SARIMA, Holt-Winter, and explanatory models, i.e., Multiple Regression and Feed Forward Artificial Neural Networks (FANNs). Economic factors such as income, relative price, exchange rates, and dummy variables of seasonality and news shock effect are explored to understand their effects on international tourism demand. Mean absolute percentage error (MAPE) is used for model comparison. It was found that the more advanced model like FANNs can produce high levels of forecasting accuracy (with MAPE ≤ 10% for all studied counties) and outperform simpler forms of explanatory model like Multiple Linear Regression. However, there are counties such as US and Japan that are suitable for Holt-Winter and SARIMA, respectively, due to their obvious seasonality and trends.
The Volatility Comovement among Stock Markets in East Asian Countries
Authors:   , Yu Weijie
Published: September 2023

Using daily indices for several East Asian and Asian emerging stock markets from 5 January 1995 to 31 December 2018, this study investigates the volatility comovement of the stock market returns in using the DCC-MGARCH model. The empirical results depict that the volatility comovement among East Asian stock markets have increased in recent years. Moreover, this correlation is stronger in the developed markets of Singapore, Hong Kong, Japan and Korea. Volatility comovement across emerging countries, namely, China, India, Thailand, Indonesia, Malaysia and Philippines, has also increased. This study also examines the volatility spillover effects in East Asia at different stages including the periods before and after the 2008 global financial crisis. We find that severe financial crises have positive and significant impacts on both volatility comovement and volatility spillover in East Asian financial markets. And after the crisis periods the cross-border correlations have become even more interconnected and complex, despite the fact that financial crisis tends to trigger higher degree of systematic integration and risk in East Asian stock markets.
Korean brand ambassadors and nationalism
Authors:   , Pathmanand Pacharawan
Published: September 2023

The purpose of this study is to examine the expression of Nationalism that it is the main reason brands chosen the Korean Brand Ambassadors.
The result of the study on the topic of Korean Brand Ambassadors and Korean nationalism explained that Korean domestic market needs a nationalist as a Brand Ambassadors to sell cultural products such as SoJu (Korean Beverage). Furthermore, in case of selling products in International market, being a nationalist is not the key for brands to have chosen the Brand Ambassador. However, if the Brand Ambassadors chose to represent himself or herself as a nationalist, they can gain more fans from within the country and also get the admiration from international fans.
Development in crosslinking system for natural rubber and epoxidized natural rubber
Authors:   , Srirachya Nuttida
Published: September 2023

This research was divided into two parts. The first part was to investigate the possibility to use maleic anhydride (MA) as a crosslinking agent for epoxidized natural rubber (ENR). The second one was to investigate the possibility to prepare the thermoreversible crosslinking of natural rubber (NR) when using glycerol (Gly) or diethylene glycol (DGly) as a thermoreversible crosslinking agent. For the first part, it was found that both ENR25 and ENR50 can be crosslinked with MA. From FT-IR spectra, the emerge of two peaks at 1735 cm-1 and 1710 cm-1 indicated that the crosslinking was taken place by the ring opening of oxirane ring of ENR with the hydroxyl groups of diacids derived from the hydrolysis of MA. Therefore, the linkages between ENR chains were the ester linkages. After swelling testing, it was found that the value of swelling index decreases with the increase of MA loading. In addition, the crosslinked ENR with MA showed better thermal resistance and higher mechanical properties than the uncrosslinked ENR. Rheographs showed that the cure characteristics of the ENR crossslinked with MA was marching behavior with a very high induction crosslinking rate. This led ENR50 to scorch during molding. For the second part, the results showed that it was possible to prepare the thermoreversible crosslinking of NR when using Gly or DGly as crosslinking agents. To achieve this, firstly NR was grafted with MA using a reactive processing method in an internal mixer without adding an initiator. This gave a product called maleated NR or MNR. The grafting was occurred by the shear action and the highest % grafting was 1.76%. The formation of MNR was confirmed by the occurrence of two peaks in FT-IR spectra at 1835 cm-1 and 1790 cm-1 attributed to the C=O of the succinic anhydride ring. The results showed after heating the MNR mixed with Gly or DGly, the obtained products had lower swelling index and higher modulus and tensile strength. This was indicated that the thermoreversible crosslinkings of MNR with Gly or DGly were taken place. The FT-IR spectra of the MNR mixed with Gly and with DGly showed that upon heating covalent ester crosslinks were formed. It was proposed here that the thermoreversible crosslinking was formed via a reaction of succinic anhydride ring with hydroxyl groups of Gly or DGly. It was found after remolding the small pieces of rubber at 150 °C the rubber sheet can be newly formed. This indicated that the thermoreversible crosslinking MNR with Gly or DGly can be reprocessed. After remolding, the mechanical properties decreased with increasing recycling round.
Optimization of protein hydrolysate preparation from split gill mushroom Schizophyllum commune
Authors:   , Wongaem Aunchalee
Published: September 2023

The optimum conditions for hydrolysate production from split gill mushroom protein using the microbial protease, Alcalase were investigated. The study was conducted using central composite design and response surface methodology. Three independent factors: hydrolysis temperature (45, 50, and 55 °C); hydrolysis time (60, 120, and 180 min); and enzyme to substrate ratio (2%, 4%, and 6% w/v) were varied, while the pH was fixed at pH 8. These three factors had a significant effect on the DH and ABTS radical-scavenging activity (p < 0.05). The optimum conditions obtained from experiments were: enzyme to substrate ratio 2%; hydrolysis time 161.4 min; and temperature 55 °C. The coefficient of determination (R2) of total protein and the IC50 value for ABTS radical-scavenging activity were 0.972 and 0.205 µg/mL, respectively, and the DH value was 50.882%. The hydrolysate was fractionated by molecular weight (MW) cut-off membranes (10, 5, 3, and 0.65 kDa). The < 0.65 kDa fraction had the highest radical scavenging ability (IC50 = 0.026 ± 0.004 µg/mL). The MW < 0.65 kDa fraction was separated by reversed-phase HPLC to yield four subfractions (F1–5). The F4 subfraction showed the highest maximum ABTS radical-scavenging activity and was selected for further analysis by quadrupole-time-of-flight-electron spin induction–mass spectrometry-based. Five antioxidant peptides were identified. In addition, the MW< 0.65 kDa fraction protected against oxidation-induced DNA damage in pBR322, pKS, and pUC19 plasmids. Furthermore, the MW < 0.65 kDa fraction, exhibited cellular antioxidant activity in a human intestinal cancer cell line (HT-29), which was dependent on the peptide concentration. These results suggested that split gill mushroom protein hydrolysate is a good source of bioactive peptides and has potential as a natural antioxidant in food production and cosmetic products.
Preceding-Jump Simplex method
Authors:   , Kafakthong Natdanai
Published: September 2023

A practical linear programming solver uses the simplex method to identify the optimal solution by iteratively searching among adjacent feasible vertices. It may visit numerous vertices before finding the optimal one for a large linear programming problem taking a long time to succeed. This research proposes a heuristic method to alleviate this issue by jumping to a new vertex close to the optimal one before performing the simplex method. The new vertex is identified by first jumping from the initial vertex along the gradient vector of the objective function or alternative direction if the objective direction points out of the feasible region and stops at the first feasible point binding at one constraint. It then shifts to a neighbor feasible point preserving previous binding constraints until it reaches the feasible vertex so the simplex method can start. The algorithm is tested on synthetic problems with the origin point as the initial vertex from 100 to 2500 variable having the same number of constraints. Moreover, the preceding jump simplex method is extended to solve general synthetic linear programming problems of 100 to 1000 variables. The experimental results show that the preceding-jump simplex method significantly reduces the number of iterations and total running time.
The measurement of transverse relaxation time (T2) using histogram from ROI setting in muscle activity study at 1.5 Tesla MRI
Authors:   , Kanyakham Kannikar
Published: September 2023

Muscle functional MRI (mfMRI) is the method to evaluate the muscle activity before and immediately after the muscle exercise by the magnetic resonance images. Exercise of skeletal muscles enhances image contrast in T2-weighted magnetic resonance (MR) images. In previous studies, the exercised physiology used multiple-spin-echo (MSE) sequences for calculating transverse relaxation time (T2) with several small regions of interest (ROI) within the target tissue. Such a method may not represent all properties of the target tissue. The purpose of this study is to measure T2 in rest and exercise muscle at 1.5 Tesla MRI using average mode values in histogram of signal intensity of whole target muscle. A PVA-gel cylindrical phantom was scanned by a 1.5 Tesla whole body MR scanner using MSE with TR 1000, 2000, 3000, 4000 ms, TE 15, 30, ……390 ms, and right thigh of eight healthy male subjects with repetition time (TR) 2000 ms. Subjects performed knee extension exercise of the right thigh 200 times and MR images were acquired at rest and after exercises. T2 was calculated by mono-exponential linear least-squares of TE 30, 45, 60, 75 ms. Results: for the phantom study, MR signal intensity increases with increasing TR. The SI curve of TR 1000 ms is lower than other TR signals, but the relaxation curve of TR 2000 ms and more show similar MR signals. In exercise study, it has been confirmed that the method using average value in histogram is the same as the conventional method. Muscle T2 in both methods, rest and after exercise, are significantly different and an increase by combining with the result of mode values from the histogram. In addition, in the muscle activity of quadriceps muscle by knee extension exercise, involvement of other than RF which has not been reported in the past, but in this study, VL, VI, and VM were also confirmed. It could be confirmed that the effect of SNR of MR images caused by the difference in the selection of RF receiver coil as well as the ROI setting is large. In conclusion, the following findings were obtained: first, the ROI setting using histogram proposed by this study can objectively obtain the characteristics within the region of interest with reduced variation. Second, the increase of T2 after the knee extension exercise is not only involved largely in RF but other muscles also slightly involved. The influence on T2 calculated by ROI setting is related to SNR because noise of MR image is affected. Therefore, T2 analysis using histogram is useful and could be applied for muscle activity, which is not confirmed by the conventional method.
Mechanisms of ceftriaxone resistance in neisseria gonorrhoeae isolated from Thai patients
Authors:   , Kueakulpattana Naris
Published: September 2023

N. gonorrhoeae is the causative agent of gonorrhea, which is one of the most important sexually transmitted disease. The multidrug resistance in N. gonorrhoeae has been increasingly reported worldwide. The objectives of this study were to investigate the prevalence and the mechanisms of ceftriaxone resistance in N. gonorrhoeae Thai isolates, and to investigate the synergistic activities of antibiotic combinations against N. gonorrhoeae isolates with reduced susceptibility or resistance to ceftriaxone. A total of 134 N. gonorrhoeae isolates were included in this study. The resistance rates of ciprofloxacin, tetracycline, penicillin G, gentamicin, azithromycin, ertapenem, fosfomycin, cefixime, and ceftriaxone were 90.30%, 82.09%, 73.13%, 59.70%, 13.43%, 1.49%, 0%, 0%, and 0%, respectively. The high prevalence of multidrug-resistant N. gonorrhoeae was found in 82.84%. Although all isolates were susceptible to ceftriaxone (MIC range of 0.001 to 0.125 mg/L with MIC50 and MIC90 of 0.002 and 0.015 mg/L, respectively.), two (1.49%) of them displayed reduced susceptibility to ceftriaxone. This is the first report of 2 N. gonorrhoeae isolates with reduced susceptibility to ceftriaxone, NG-083 (ST723) and NG-091 (new ST) in Thailand. Both isolates had mosaic PBP2 pattern XXXIV, L421P substitution in PBP1, an adenine deletion in the 13-bp inverted repeat sequence of the mtrR promoter region, a H105Y substitution in the MtrR repressor, and G120K and A121N substitutions in PorB porin. The result from NG-MAST showed the heterogeneous populations (29 STs) among 31 representative strains of N. gonorrhoeae . The activities of ceftriaxone plus azithromycin, fosfomycin, gentamicin, or ertapenem were evaluated by checkerboard method against the 2 isolates with reduced susceptibility to ceftriaxone. There was no synergistic activity of these antibiotic combinations. The best combination was ceftriaxone plus azithromycin, which showed the lowest FICIs of additive and was confirmed by time-kill method. The results showed that this combination had no synergistic activity but had bactericidal activity. This study showed high resistance rates of antibiotics previously used for treatment of gonorrhea, e.g., penicillin G, tetracycline, and ciprofloxacin. However, no isolates were resistant to ceftriaxone, suggesting that it is still active against N. gonorrhoeae Thai isolates. Mutations in, penA, mtrR promoter, mtrR, and porB genes were associated with reduced susceptibility to ceftriaxone. Therefore, antimicrobial resistance surveillance and rapid diagnosis are important to limit the emergence and spread of antibiotic-resistant N. gonorrhoeae isolates.
Synthesis of high efficiency amidoxime polymer adsorbents for uranium extraction from seawater by radiation-induced polymerization
Authors:   , Wongjaikham Wijittra
Published: September 2023

This study synthesized amidoxime polymer gel for uranium extraction from seawater through a polymerization process with gamma ray or UV-C radiation. The synthesis started with a mixture of acrylonitrile (AN) and methacrylic acid (MAA) monomers together with methylene bisacrylamide as a crosslinker and hydrogen peroxide in the case of UV radiation. The mixture was irradiated with gamma ray at various doses or UV-C for various durations. The resulting polymer gel was ground into fine particles and immersed in a hydroxylamine hydrochloride solution for 90 minutes in order to convert the chemical functional group from the cyano group into the amidoxime group. Results of laboratory-scale uranium extraction showed that for the case of amidoxime polymer gel prepared by gamma radiation, the ratio of monomer AN:MAA of 80:20, the amount of the crosslinker of 0.8 g/100 mL monomer, and 40 kGy gamma ray dose exhibited the highest uranium adsorption capacity. For the amidoxime polymer gel polymerized by UV-C radiation, the ratio of monomer AN:MAA of 80:20, the amount of the crosslinker of 1 g/100 mL monomer, hydrogen peroxide of 60 mL/100 mL monomer, and irradiation time of 8 hours exhibited the highest uranium adsorption capacity. The usage repeatability test indicated that after 8 cycles of repeated use, the polymer gel prepared from gamma ray did not show a decrease in the adsorption efficiency while the polymer gel prepared from UV-C showed a decrease in the adsorption efficiency of 50%. The field test results in natural seawater in front of Phuket Marine Biological Center (PMBC), Phuket province, Thailand for 8 weeks revealed that the polymer gel prepared from gamma ray exhibited the uranium adsorption of 0.05 mg/g while the polymer gel prepared from UV-C exhibited the uranium adsorption of 0.035 mg/g.
Assessment of attitudes and knowledge of general dental practitioners in providing implant maintenance
Authors:   , Rudeejaraswan Aimwalee
Published: September 2023

This study aimed to survey the attitudes and knowledge of Thai general dental practitioners (GDPs) in proving dental implant maintenance care. The online questionnaire was sent to Thai GDPs who graduated between 2000 and 2016. Of the returned 435 questionnaires, 429 completely filled were included for analysis. 76% of the participants were female and 24% were male. Half of the participants were aged 28-33 years old and 78% of the participants have been working as a GDP 10 years or below.�There were 64.3% and 59.4% of the participants who agreed that dental implant surgery and restoration should only be obligated by specialists. Moreover, 22.4% agreed that dental implant maintenance care should be performed by specialists. The majority of the participants (88.5%) reported their willingness to give comprehensive oral examination on natural teeth and implant, only half of them (51%) would provide dental implant maintenance care. Significant positive correlation between attitudes and knowledge of the participants were found. GDPs tended to provide implant maintenance care according to their knowledge score. However, GDPs still felt less confident to provide dental implant maintenance care and treat the implant problems. These obstacles may be due to insufficient knowledge and not well-equipped practice setting.
Characterization of PmSpӓtzle and SPIPm5 from black tiger shrimp Penaeus monodon
Authors:   , Boonrawd Sittichai
Published: September 2023

Humoral response proteins in shrimp, antimicrobial proteins (AMPs) and proteinase inhibitors, are implicated in host defenses against the pathogen infection because their expression is changed in response to microbial infection. After the pathogen infection in shrimp, the Spätzle protein is synthesized and activated the pathogenic signaling via Toll pathway by its active protein for the synthesis of AMPs. In this study, three PmSpätzle isoforms, PmSpz1, 2 and 3 genes, were identified in Penaeus monodon. The PmSpz1 gene was chosen for studied in details. Its gene was expressed in all shrimp tissues tested and in response to WSSV infection. Western blot analysis of hemolymph showed that the PmSpz1 mostly existed as an active form awaiting to activate Toll pathway. Injection of a recombinant PmSpz1 rendered the shrimp less susceptible to the WSSV challenge. The recombinant of active Spätzle activated the synthesis of AMP genes: crustinPm1, crustinPm7, ALFPm3, penaeidin3 but not penaeidin5. It is indicating that the expression of all antimicrobial proteins but not penaeidin5 was expressed under the regulation of Toll pathway. For SPIPm5 protein, the Kazal-type serine proteinase inhibitor from P. monodon was also studied. Its transcripts were also expressed in all tissues tested and its gene expression was up-regulated by heat stress, WSSV and YHV. Injection of rSPIPm5 into shrimp to mimic heat stress condition had more or less no effect on the crustinPm1, penaeidin3, penaeidin5, Hsp70, SPIPm2 and SPIPm5. The effect of rSPIPm5 protein inhibited the hemolymph proPO activity. In survival experiments, the rSPIPm5 could also prolong the shrimp from pathogen infection, WSSV, YHV, Vibrio harveyi and Vibrio parahaemolyticus in shrimp. The increased endurance against the microbial infection was due to the inhibitory effects presumably activated by rSPIPm5 on viral replication and bacterial growth but not the expression of AMPs gene. The microbial inhibitory effects may be activated by rSPIPm5. Therefore, the SPIPm5 plays an important role in shrimp innate immunity against the viral and bacterial infection besides its function as a proteinase inhibitor.
Comparative study between
vitamin B 1-6-12 and vitamin B 12 for neurosensory recovery
after bilateral sagittal split ramus osteotomy
Authors:   , Trising Worawee
Published: September 2023

A major complication from Bilateral Sagittal Split Ramus Osteotomy (BSSRO) is inferior alveolar nerve injured that manifest as neurosensory disturbance (NSD) on the lower lip, chin. Although the NSD is not a life-threatening problem but it impacts the patient's daily life. Vitamin B is commonly used to treat peripheral neuropathy but it is only few study for NSD from BSSRO. The aim of this study was to evaluate the effect of oral vitamin B1-6-12 and vitamin B12 on NSD after BSSRO. The study design was as a randomized, single blinded control trial of 75 patients who were NSD from BSSRO (n=25). The first group was vitamin B1-6-12 group that taking 1 tablet 3 times daily. The second group was vitamin B12 group that taking 1 tablet 3 times daily. The third group was the control group without taking vitamin B. Clinical Neurosensory Testing (CNT) was performed with static two-point discrimination, moving two-point discrimination, light touch and pinprick at preoperation, immediate, 1 week, 1 month, 3 months and 6 months and converted to Global Sensitivity Score (GSS). GSS was calculated to recovery proportion and was analysed with Friedman test and post hoc analysis with Wilcoxon signed rank test for intragroup comparison on the passing time and Kruskal Wallis H test and post hoc with Mann Whitney U test were used for intergroup comparison. Results showed significantly increasing recovery improvement in all groups on the passing time (p<0.05). Vitamin B1-6-12 orally were significantly highest recovery proportion when comparing with and control vitamin B12 at 6 months (p=0.038, p=0.033).