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2020

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Tuning Of Metal Ion Selectivity By Varying Number Of Coordinating Atoms In Quinoline-Derived Fluorescent Sensors, Jutawat Hojitsiriyanont Jan 2020

Tuning Of Metal Ion Selectivity By Varying Number Of Coordinating Atoms In Quinoline-Derived Fluorescent Sensors, Jutawat Hojitsiriyanont

Chulalongkorn University Theses and Dissertations (Chula ETD)

Both Cd2+ and Zn2+ are metal ions in group 12 elements with very different toxicities but similar binding properties to most organic and biological ligands. In this work, a series of quinoline derivatives were synthesized and studied with an aim for Cd2+ selective turn-on fluorescent sensors. The structures of the compounds were designed to systematically evaluate the effects of amino protons, number of N-coordinating atoms, quinoline/picoline moieties and substituents on the sensing properties. The association constants of all synthesized ligands were studied by UV-vis absorption titration in aqueous solution. The results revealed that the ligands having 6- and 4- donor …

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Inhibitory Activity Of Metabolites From Mangosteen Roots Garcinia Mangostana L. On Hepatocellular Carcinoma And Colon Cancer Cell Growth, Kedkran Koopklang Jan 2020

Inhibitory Activity Of Metabolites From Mangosteen Roots Garcinia Mangostana L. On Hepatocellular Carcinoma And Colon Cancer Cell Growth, Kedkran Koopklang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Liver cancer is one of the most common deadliest diseases both worldwide and in Thailand. Because of its rich and dual blood supply, malignant tumors in the liver could grow proliferative and rapidly spread to another organ. This process was called Metastasis, the major cause of human death. Mangosteen (Garcinia mangostana L.) generally known as a queen of fruits, has been widely studied in medicinal applications for many decades, due to plenty of bioactive metabolites such as xanthones as a major component. Nonetheless, reports about bioactivities of minor components were barely known. In this study, metabolites isolated from mangosteen roots …

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Potential Of Antimicrobial Peptides Against Bacterial Pathogens Causing Bovine Mastitis, Kwantida Popitool Jan 2020

Potential Of Antimicrobial Peptides Against Bacterial Pathogens Causing Bovine Mastitis, Kwantida Popitool

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bovine mastitis is a common disease in dairy cows. The majority causes of bovine mastitis disease is an intramammary bacterial infection via the teat orifice. In general, antibiotics are used for bovine mastitis treatment, its inappropriate usage leads to antibiotic-resistance problem and residue in meat and dairy products. One of the alternative ways against pathogen to reduce antibiotic usage is antimicrobial peptides which are innate immune of life. Three cationic peptides as Pm11, Pep64, and L10 peptides were evaluated for an antimicrobial activity to gram-positive and gram-negative bacteria. Pm11 has shown the best potent antimicrobial activity with minimum bactericidal concentration …

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Synthesis And Encapsulation Of 1,3,5-Triazine Derivatives As Anticancer Agent, Monnaya Chalermnon Jan 2020

Synthesis And Encapsulation Of 1,3,5-Triazine Derivatives As Anticancer Agent, Monnaya Chalermnon

Chulalongkorn University Theses and Dissertations (Chula ETD)

The 1,3,5-triazine scaffold is known for its versatile biological activities especially as an anticancer agent, but a limitation of 1,3,5-triazine is the ability to reach cancer cells thus affecting its anticancer potency. In this work, the anticancer activity of twelve 1,3,5-triazine derivatives was evaluated against two colon cancer cell lines along with an investigation of a drug delivery system (DDS) using calcium citrate nanoparticles (CaCit NPs). Results from the biological evaluation showed that there was a variation in the anticancer activity of 1,3,5-triazine derivatives which some of them exhibited comparable activity to the reference drug cisplatin. Compound 2a and 3d …

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Fluorescence Sensors From Pyreno[4,5-D]Imidazole Derivatives, Nichapa Chanawungmuang Jan 2020

Fluorescence Sensors From Pyreno[4,5-D]Imidazole Derivatives, Nichapa Chanawungmuang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Herein, The five fluorescent probes (P1, P2, P3, P4 and P5) based on pyreno[4,5-d]imidazole were successfully prepared in two steps from pyrene in 26 – 40% overall yields. After that, all of the compounds were studied the photophysical properties and selectivity for sensing metal ions. The results showed compound P5 was not selective to metal ions while the others (P1, P2, P3 and P4) were selective to detection of trivalent metal ions such as Bi3+, Al3+, Cr3+ and Fe3+ in CH3CN. However, only compound P2 with 2-hydroxyl phenyl substituent on imidazole ring formed complexation reaction selectively towards bismuth (III) ions …

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Bacterial Cellulose Composites For Target Analyte Preconcentration In Analytical Applications, Panlop Lormaneenopparat Jan 2020

Bacterial Cellulose Composites For Target Analyte Preconcentration In Analytical Applications, Panlop Lormaneenopparat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bacterial cellulose (BC) is a well-known natural material with desirable properties including biocompatibility, biodegradability, hydrophilicity, high mechanical strength, high porosity, and broad chemically modifiable capacity. Herein, we incorporate carboxymethyl cellulose (CMC) in BC hydrogel to improve the swelling property and prevent collapsing of 3D bacterial cellulose network upon drying. In addition, gold nanoparticles (AuNPs) were successfully embedded within the BC/CMC composite using in situ chemical reduction. Moreover, AuNPs were uniformly distributed in BC/CMC matrix with a diameter of approximately 13 nm. The freeze-dried BC/CMC/AuNPs composite was subsequently used for adsorption of targeted analytes for laser desorption/ionization mass spectrometry. In particular, …

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Design And Synthesis Of Modified Chitosan/Collagen Coated-Gold Nanoparticles As A Carrier For Anticancer And Antiinflammatory Agents, Naruthai Hongsa Jan 2020

Design And Synthesis Of Modified Chitosan/Collagen Coated-Gold Nanoparticles As A Carrier For Anticancer And Antiinflammatory Agents, Naruthai Hongsa

Chulalongkorn University Theses and Dissertations (Chula ETD)

The proposes of this research are to improve the delivery efficiency of AuNPs. One of the problems with drug loading and drug degradation, the drug was loaded onto the surface of the gold particles, adheres to the outer of the surface, which was easy to decompose in the body. In this work, we have developed the coated AuNPs by modified chitosan (Bi-QCS), which the Biotin-Quat188-AuNPs@collagen (Bi-QCS-AuNPS@collagen) was designed as follow: (i) collagen was used as a reducing agent and a stabilizing agent in the AuNPs@collagen, while (ii) modified chitosan (positive charge polymer) was coated on the outer layer, which modified …

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Building Detection From Remote Sensing Images Using Yolo, Noppadon Pumpong Jan 2020

Building Detection From Remote Sensing Images Using Yolo, Noppadon Pumpong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Building detection system through the remote sensing of images has been widely studied. In this thesis, we propose a model for detecting buildings at airports in Asia through different levels of remote sensing image. The proposed model is improved using the You Only Look Once (YOLO) algorithm based on the convolutional neural network (CNN). We also adjust an inputted image to our model using the Jet Saliency Map. The buildings to be detected in this study are the passenger terminals, the control towers, the cargo buildings, and the hangars. The data set has been collected from 322 different airports in …

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Hydromorphological Changes Of Chi River, Mueang District, Khon Kaen Province, Pawat Wattanachareekul Jan 2020

Hydromorphological Changes Of Chi River, Mueang District, Khon Kaen Province, Pawat Wattanachareekul

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis focuses on the analysis of hydrology coupled with geomorphology for river management such as flood mitigation and river restoration. Morphological Quality Index (MQI) is used for assessing hydro-morphological conditions from part of the Chi River (67 km long) at Khon Kaen province, a major river in north-eastern Thailand. This study area has been suffering from unexpected and repeated flooding. MQI is applied to evaluate the degree of hydro-morphological alteration in terms of relative scores (from 0 to 1). Basically, in case that MQI score equals 1, it means the area has no any alteration. On the other hand, …

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Pyrrolidinyl Peptide Nucleic Acid Probe Capable Of Crosslinking With Dna, Penthip Muangkaew Jan 2020

Pyrrolidinyl Peptide Nucleic Acid Probe Capable Of Crosslinking With Dna, Penthip Muangkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

DNA interstrand cross-linking (ICL) is a phenomenon in which two strands of the DNA (most often as part of the same DNA duplex) bind together via a covalent bond. This process prevents the DNA strand dissociation, which is essential for its biological functions, and thus is extremely damaging to cells. To overcome the problem of non-specificity associated with general DNA cross-linking agents, a cross-linkable probe in which the reactive group is placed on the probe that can specifically recognize part of the DNA target. The strong binding affinity and biological stability of the pyrrolidinyl peptide nucleic acid (acpcPNA) inspired us …

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Effects Of Valproic Acid On Fatty Acid Production In Microorganisms And Bioactive Compounds From Feroniella Lucida (Scheff.) Swingle And Termite-Associated Fungus Isfb10, Prapassorn Poolchanuan Jan 2020

Effects Of Valproic Acid On Fatty Acid Production In Microorganisms And Bioactive Compounds From Feroniella Lucida (Scheff.) Swingle And Termite-Associated Fungus Isfb10, Prapassorn Poolchanuan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Valproic acid or valproate (VPA) is a drug for the treatment of epilepsy, bipolar disorder, migraine headaches and neuropathic pain. Unfortunately, VPA has many side effects. In this work, it was found that productions of some fatty acids were significantly affected by VPA at the concentration of 100 μM. Further exploration of VPA on fatty acid production in microorganisms including fungi, yeast, and bacteria, as well as representative gut microbiome. This work showed that VPA could enhance, reduce or completely inhibit the production of some fatty acids. VPA could induce the production of trans-9-elaidic acid that was previously found to …

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Anti-Oxidant And Anti-Inflammatory Compounds From Magnolia Liliifera (L.) Baill. Flower And Dendrobium Signatum Rchb.F., Prajak Khumploy Jan 2020

Anti-Oxidant And Anti-Inflammatory Compounds From Magnolia Liliifera (L.) Baill. Flower And Dendrobium Signatum Rchb.F., Prajak Khumploy

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, a purification of the EtOAc crude extract of Dendrobium signatum Rchb.f. aerial parts was performed fifteen compounds (1-15) and the hexane crude extracts of Magnolia liliiferra (L.) Baill. were further isolated to accomplish three compounds (16-18). They yielded one new picrotoxane sesquiterpene, 7-hydroxydendroterpene B (2) and a new a-pyrone, (-)-6R-signatone (4), along with sixteen known compounds. These included dendroxine (1), crystallinin (3), dendrocandin B (5), dendrocandin I (6), 6''-de-O-methyldendrofindlaphenol A (7), p-hydroxyphenylethyl-p-coumarate (8), 3,4-dihydroxy-5,4'-dimethoxybibenzyl (9), 3-methoxy-5-[2-(4-methoxyphenyl) ethyl]phenol (10), 4,4'-dihydroxy-3,5-dimethoxybibenzyl (11), naringenin (12), (2S)-homoeridodictyol (13), (2S)-homohesperetin (14), (-)-syringaresinol (15), (+) sesamin (16), (+) fargesin (17) and (-) kobusin …

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Biodegradation Of Polycyclic Aromatic Hydrocarbons Commonly Found In Coal Slurry Using White Rot Fungi Isolated From East Kalimantan, Retno Wulandari Jan 2020

Biodegradation Of Polycyclic Aromatic Hydrocarbons Commonly Found In Coal Slurry Using White Rot Fungi Isolated From East Kalimantan, Retno Wulandari

Chulalongkorn University Theses and Dissertations (Chula ETD)

Fifty specimens of white-rot fungi were identified and placed into 6 families and 30 species. Two new records of resupinate fungi (Basidiomycota) were discovered and reported for Indonesia: Ceriporia inflata and Ceriporia lacerata. Furthermore, a four-step screening protocol to select WRF has been conducted. These stepwise protocols have selected Trametes polyzona PBURU 12 based on its superior performance among the 30 isolates tested in this experiment with laccase as the major LMEs produced. Plackett-Burman’s design was used for screening multiple factors at a time. The result suggested that the highest positive effects influencing laccase production by PBURU 12 were glucose, …

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Tetrabromomethane-Mediated Desulfurization For Synthesis Of Isothiocyanates From Amines, Saharat Techapanalai Jan 2020

Tetrabromomethane-Mediated Desulfurization For Synthesis Of Isothiocyanates From Amines, Saharat Techapanalai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Isothiocyanate considered as an important building block for pharmaceutical industry. Traditional methods for preparation of isothiocyanate involved the desulfurization of dithiocarbamate salt from amine using oxidizing agent. Although those methods are efficient, however, all of them require the use of toxic reagent, strong oxidizing agent, multiple step synthesis, harsh condition and large amount of metal catalyst. Therefore, in this research, we develop two mild methods to synthesize isothiocyanates from amines using low toxic reagent. For the first process, we were able to demonstrate the use of photocatalyst, safranin O to convert dithiocarbamate salt of 4-bromoaniline into 4-brophenyl isothiocyanate in 48% …

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Phytoalexin And Biomarker Peptide Detection Using Mass Spectrometry, Sasikarn Komkleow Jan 2020

Phytoalexin And Biomarker Peptide Detection Using Mass Spectrometry, Sasikarn Komkleow

Chulalongkorn University Theses and Dissertations (Chula ETD)

Mass spectrometry (MS) has been one of the scientific techniques most commonly used in different areas. Therefore, the current research was carried out in order to investigate the role of MS in biological analysis. This study is divided into two main parts. The first part used MS imaging to reveal the ability of the technique for imaging metabolites directly from plant tissue. Thai rice varieties were used to investigate the production and distribution of diterpenoid phytoalexins using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). Results revealed the successfully detection of 5 types of diterpenoid phytoalexins on RD6 rice leaf tissue, …

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Synthesis Of 5-Phenoxyprimaquine Derivatives And Their Tetraoxane Conjugates As Anti-Malarial Agents, Somruedee Jansongsaeng Jan 2020

Synthesis Of 5-Phenoxyprimaquine Derivatives And Their Tetraoxane Conjugates As Anti-Malarial Agents, Somruedee Jansongsaeng

Chulalongkorn University Theses and Dissertations (Chula ETD)

Currently, the development of the new anti-malarial drug for the treatment of the increasing drug-resistant strains of malaria was necessary. Therefore, this research was performed by synthesis and evaluation of their antimalarial activity for the development of primaquine which currently was used for anti-malarial drug. The substituents group on 5-phenoxyprimaquine derivatives which had the highest therapeutic index and less toxicity than primaquine were emphasized. The effect of substituted group at para position was studied. Three new derivatives with CN (7e), CF3 (7g), CONH2 (7h) substituents, and five known derivatives with OMe (7b), Br (7c), Cl (7d), F (7f) substituents and …

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Variation Of Symbiodiniaceae In Broadcaster Acropora Humilis And Brooder Pocillopora Damicornis Corals, Suppakarn Jandang Jan 2020

Variation Of Symbiodiniaceae In Broadcaster Acropora Humilis And Brooder Pocillopora Damicornis Corals, Suppakarn Jandang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Reef-building corals sustain a symbiotic relationship with single-cell algae belonging to family Symbiodiniaceae. Symbiotic algae contribute up to 50-95% of the metabolic needs by supplying photosynthetic products to the coral host. Therefore, the symbiosis between corals and Symbiodiniaceae is essential for the development and survival of coral reefs. Over the past years, significant losses and changes in coral reef ecosystems have been caused by anthropogenic activities and natural phenomena. Thus, relevant national organizations have raised awareness regarding the conservation of coral populations. Our Reef Biology Research Group, Department of Marine Science, Chulalongkorn University have been producing corals using a sexual …

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Anti-Proliferative Metabolites From The Root Of Calophyllum Inophyllum L., Syahadatain Nor Haerani Jan 2020

Anti-Proliferative Metabolites From The Root Of Calophyllum Inophyllum L., Syahadatain Nor Haerani

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to isolate secondary metabolites from the root of C. inophyllum L. and to evaluate their anti-proliferative activities against hepatocellular carcinoma and colorectal cancer cells. Chromatographic fractionation of the n-hexane and ethyl acetate crude extracts led to the isolation of two new (1 and 2) and twelve known xanthones (3-14). In addition, metabolites 4, 6 and 8 were isolated from the genus Calophyllum for the first time. All metabolites were evaluated for their anti-proliferative activity against Hep-G2 and HCT-116 cell lines. Metabolites 5 and 14 showed the most active metabolites against both cancer cells, as well as they …

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Effect Of Dealumination And Desilication Of Beta Zeolite On Performance Of Nickel Catalysts In Hydroisomerization For Bio-Jet Fuel Production, Warodom Hunsiri Jan 2020

Effect Of Dealumination And Desilication Of Beta Zeolite On Performance Of Nickel Catalysts In Hydroisomerization For Bio-Jet Fuel Production, Warodom Hunsiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

-The Global aviation fuel consumption tends to increase. In recent years, the European Union has announced that fossil fuels jet fuel must be mixed with 10% biofuels in 2020. bio-jet fuel production has many processes such as biomass pyrolysis. or hydro-p

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Roles Of Bacterial Toxin Receptor And Piwi-Interacting Rna Of Pacific White Shrimp Penaeus Vannamei In Response To Vibrio Parahaemolyticus-Causing Acute Hepatopancreatic Necrosis Disease Infection, Waruntorn Luangtrakul Jan 2020

Roles Of Bacterial Toxin Receptor And Piwi-Interacting Rna Of Pacific White Shrimp Penaeus Vannamei In Response To Vibrio Parahaemolyticus-Causing Acute Hepatopancreatic Necrosis Disease Infection, Waruntorn Luangtrakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Acute hepatopancreatic necrosis disease (AHPND) or Early mortality syndrome (EMS) caused by virulent strains of Vibrio parahaemolyticus AHPND (VPAHPND) has been a leading cause of significant losses of shrimp production. In this study, we aim to explore the response and the role of immune-related gene/protein and small RNA in the VPAHPND-infected shrimp. This research was divided into 2 parts. In the first part, we identified candidate genes of VPAHPND toxin receptor and further confirmed its function as a VPAHPND toxin receptor. APN has been reported as a Cry toxin from Bacillus thuringiensis, whose structure is similar to VPAHPND toxin. Therefore, …

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Synthesis Of 1,2-Naphthoquinone Derivatives As Α-Glucosidase Inhibitors, Trang Pham Thi Jan 2020

Synthesis Of 1,2-Naphthoquinone Derivatives As Α-Glucosidase Inhibitors, Trang Pham Thi

Chulalongkorn University Theses and Dissertations (Chula ETD)

For a couple of decades the bioactivity of quinone has been considered as privileged structure-based drug design. In this research, 4-phenylamino, 4-alkylamino, 4-alkylphenylamino, 4-phenoxy and other derivatives of 1,2-naphthoquinone were synthesized, evaluated for their anti α-glucosidase activity and elucidated for their structure-activity relationship. The results indicated that multiple factors affecting to the α-glucosidase inhibition included π-π interaction, hydrophobic interaction and hydrogen bonding with the enzyme. In general, the main factor affecting the activity was the more favorable 1,2-dione production. The presence of electron withdrawing substituents on the phenyl ring and heteroatom linker bound to the quinone skeleton increased the activity. …

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Improved Adaptive Fractional Order Differential Method For Medical Image Enhancement, Wasin Tranghiranyathorn Jan 2020

Improved Adaptive Fractional Order Differential Method For Medical Image Enhancement, Wasin Tranghiranyathorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, we propose a construction of a new 5x5 fractional order differential mask that uses sixteen directions of gradient operator and weights each pixel in the mask by the Euclidean distance from the center of the mask. Then, we apply this new mask to the Adaptive Fractional Differential Algorithm (AFDA). The AFDA allows the optimal fractional order of each pixel to be obtained using an adaptive function constructed based on the area feature of image. Experimental results for medical images, show that the AFDA with the new mask gives better image enhancement than the original AFDA. It makes …

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Drought Tolerant Gene Identification By Rice Genome Comparison And Gene Characterization In Arabidopsis Plant Model, Chutarat Punchkhon Jan 2020

Drought Tolerant Gene Identification By Rice Genome Comparison And Gene Characterization In Arabidopsis Plant Model, Chutarat Punchkhon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Abiotic stresses, especially drought and salt stresses can affect plant growth and productivity. 'Kao Dawk Mali 105' ('KDML105') rice is one of the crops which has to face both drought and salt stresses as it is grown in rain-fed saline soil in the northeastern region of Thailand, where the irrigation is limited. CSSL104, a chromosome substitution line with 'KDML105' genetic background, was developed in order to improve drought tolerant ability of 'KDML105' rice by transferring the drought tolerant (DT)-QTL region from double haploid line, DH103. Photosynthesis parameters of CSSL104 and its parental lines, 'KDML105' and DH103, were investigated, when they …

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Synthesis Of Sulfonamide Chalcones As Α-Glucosidase Inhibitors, I Putu Sukanadi Jan 2020

Synthesis Of Sulfonamide Chalcones As Α-Glucosidase Inhibitors, I Putu Sukanadi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Diabetes mellitus occurs from deficiencies in insulin secretion or insulin resistance which leads over time to high risk for long-term macro-and microvascular complications. Diabetes mellitus type 2 contributes to more than 90% of all cases worldwide. One approach of treatment for this disorder is utilizing α-glucosidase inhibitors. Certain sulfonamides and chalcones are considered as viable candidates that are effective in reducing hyperglycemia. Forty-seven sulfonamide chalcones were synthesized by the Claisen-Schmidt reaction with various substituents on the A, B, and C-rings furnishing the desired products with 50-95 %yield. All compounds were-tested for α-glucosidase inhibitory activity. Twenty-nine compounds exhibited a very strong …

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Sexual Behaviors Of Indochinese Long-Tailed Macaque Macaca Fascicularis In Comparison With Sundaic Long-Tailed Macaque, Prangmas Kumpai Jan 2020

Sexual Behaviors Of Indochinese Long-Tailed Macaque Macaca Fascicularis In Comparison With Sundaic Long-Tailed Macaque, Prangmas Kumpai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Regarding to the previous studies reported that the past hybridization event between rhesus (Macaca mulatta; Mm) and long-tailed (M. fascicularis; Mf) macaques was occurred by the southward introgression of male Mm into Mf population, thus the Mf originating from Indochinese region carried higher level of genetic admixture of Mm ancestry than the Mf living in Sundaic region. Since it was reported that Mf are non-seasonal breeder while Mm are seasonal breeder, thus, it is interesting to compare the sexual behaviors between Indochinese and Sundaic Mf. Mf populations at Wat Haad Moon Kra Beau, Pichit province (WHM; 16° 51′N) and Khao …

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Electrochemical Paper-Based Immunosensor For Biomarkers Detection, Suchanat Boonkaew Jan 2020

Electrochemical Paper-Based Immunosensor For Biomarkers Detection, Suchanat Boonkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation focused on the development of electrochemical paper-based immunosensor for determining essential biomarkers by using a label-free immunoassay. This dissertation can be divided into four main parts. In the first part, an origami paper-based analytical device (oPAD) was developed for c-reactive protein (CRP) detection. oPAD was designed to combine the preparation of immunosensor and detection step into a single device. A gold nanoparticle modified graphene screen-printed carbon electrode (AuNPs/G/SPCE) was utilized to enhance the sensitivity of the electrode. The developed sensor was successfully applied to determine CRP in a certified serum sample. For the second part, an electrochemical paper-based …

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Gonadal Sex Differentiation Of Rice Field Frog Hoplobatrachus Rugulosus (Wiegmann, 1834), Thrissawan Traijitt Jan 2020

Gonadal Sex Differentiation Of Rice Field Frog Hoplobatrachus Rugulosus (Wiegmann, 1834), Thrissawan Traijitt

Chulalongkorn University Theses and Dissertations (Chula ETD)

The rice field frog Hoplobatrachus rugulosus, a species widely distributed in Thailand, has potential to be a model in many fields of research. A preliminary study demonstrated that the gonadal differentiation in this frog showed tendency to be an undifferentiated type since all individuals had ovaries at complete metamorphosis. However, the information was still unclear. Therefore, this study aimed to investigate the chronology and pattern of gonadal sex differentiation as well as steroidogenic potential of gonadal tissues during development. The frog embryos were obtained by stimulating fertilization in laboratory under natural light and temperature conditions. Their developmental stage was identified …

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Porcine Reproductive And Respiratory Syndrome Virus: Genetic Diversity, Pathogenesis And Modified-Live Vaccines, Adthakorn Madapong Jan 2020

Porcine Reproductive And Respiratory Syndrome Virus: Genetic Diversity, Pathogenesis And Modified-Live Vaccines, Adthakorn Madapong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Porcine reproductive and respiratory syndrome virus (PRRSV) is a causative agent of PRRS that reproductive failure in sows and respiratory problems in piglets is the hallmark of the disease. Recently, several PRRSV modified live vaccines (MLV) are available, and vaccine selection is a concern. Therefore, the objectives of this study were: 1) to investigate the genetic diversity of Thai PRRSV isolates during 2001-2017; 2) to evaluate the pathogenicity of Thai PRRSV isolates; 3) to determine the efficacy of PRRSV MLV against Thai field PRRSV infection and 4) to investigate the effectiveness of PRRSV MLV when administered via intramuscular (IM) and …

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Microbiological Quality Of And Antimicrobial Resistance In Commercial Probiotic Products For Food Animals In Thailand, Hoang My Tran Jan 2020

Microbiological Quality Of And Antimicrobial Resistance In Commercial Probiotic Products For Food Animals In Thailand, Hoang My Tran

Chulalongkorn University Theses and Dissertations (Chula ETD)

A total of 45 commercial probiotic products for food animals were investigated for the number of viable cells, bacterial species and the presence of antimicrobial resistance (AMR) genes. All products were enumerated for viable bacterial cells of Lactobacillus, Bacillus and Enterococcus. Confirmation of species was carried out by multiplex Polymerase Chain Reaction (PCR) for Lactobacillus (n=20), Enterococcus (n=20), and Amplified Ribosomal DNA Restriction Analysis (ARDRA) for Bacillus (n=190). The presence of Clostridium species was examined by PCR. The contamination of E. coli and Salmonella was also determined. Minimal Inhibitory Concentrations (MICs) for 14 antimicrobials was examined in the bacterial isolates …

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Localization Of Tilapia Tilapinevirus By In Situ Hybridization In The Brain Of Nile Tilapia (Oreochromis Niloticus), Hung Dinh Nguyen Jan 2020

Localization Of Tilapia Tilapinevirus By In Situ Hybridization In The Brain Of Nile Tilapia (Oreochromis Niloticus), Hung Dinh Nguyen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Tilapia tilapinevirus or tilapia lake virus (TiLV) is an emerging virus that poses a significant negative impact on farmed tilapia globally. Abnormal behaviours such as lethargy, loss of appetite, erratic swimming, stop schooling have been recorded during disease occurrence, which is possibly linked to brain activities. Previous studies described detection of the virus in multiple organs of infected fish; however, little is known about the in-depth localization of the virus in the central nervous system. Herein, we determined the distribution of TiLV and histopathological alterations in the entire brain of Nile tilapia experimentally infected fish. By in situ hybridization (ISH) …

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