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2019

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Characterization Of Mait Tcr Repertoire Of Gastrointestinal Tract And Peripheral Blood Mait Cells, Thidarat Kongkaew Jan 2019

Characterization Of Mait Tcr Repertoire Of Gastrointestinal Tract And Peripheral Blood Mait Cells, Thidarat Kongkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

Mucosal-associated invariant T (MAIT) cells are an innate-like T cell that rapidly respond to infection. MAIT cells are αβ T cells that possess a Vα7.2 (TRAV1-2) TCR with mostly pairing to TRAJ33, TRAJ20 or TRAJ12 and predominantly TRBV20-1, TRBV6-1 and TRBV6-4. MAIT T cell receptors (TCR) repertoire have been previously studied in peripheral blood. However, data on MAIT TCR repertoire in gastrointestinal tract are lacking. We studied 2 individuals who are underwent esophagogastroduodenoscopy (EGD) and colonoscopy. Blood and biopsies were obtained. PBMCs were isolated from blood and LPLs were isolated from biopsies. Due to the low number of MAIT cells …

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Measurement Of The Whole Body, Eye Lens And Extremity Occupational Exposures In Nuclear Medicine Staff At King Chulalongkorn Memorial Hospital, Siriwan Sisai Jan 2019

Measurement Of The Whole Body, Eye Lens And Extremity Occupational Exposures In Nuclear Medicine Staff At King Chulalongkorn Memorial Hospital, Siriwan Sisai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Due to the epidemiology evidence of cataract and eye lens opacity, ICRP Publication 118 in 2012, recommended the new eye lens dose limit of occupational exposure at 20 mSv/year, averaged over 5-year periods, no single year exceeding 50 mSv. For the public eye lens dose limit is 15 mSv/year. After ICRP changed the eye lens dose limit, many reports on eye lens dose measurement using thermoluminescent dosimeter (TLD) from interventional radiologists and interventional cardiologists were published. Few reports on eye lens dose measurement in nuclear medicine (NM) personnel were found. The primary objective of this study is to measure whole …

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A Feasibility Study Of Diffusion Weighted Imaging And Parametric Response Map Analysis For Treatment Response Prediction In Nasopharyngeal Cancer, Titiya Jirawatwanith Jan 2019

A Feasibility Study Of Diffusion Weighted Imaging And Parametric Response Map Analysis For Treatment Response Prediction In Nasopharyngeal Cancer, Titiya Jirawatwanith

Chulalongkorn University Theses and Dissertations (Chula ETD)

Diffusion-weighted imaging (DWI) is an MRI technique which provides functional information of tissue by detecting microscopic motion of water molecules. The change of apparent diffusion coefficient (ADC) derived from DWI was used as an imaging biomarker for treatment response prediction in cancers. However, it was based on whole-tumor analysis which did not reflect heterogeneity within the tumor. To overcome this limitation, a new method called parametric response map (PRM) analysis was proposed to evaluate response by quantifying voxel-wise changes in ADC. Here we investigated the use of PRM analysis on ADC from DWI as an imaging biomarker for treatment response …

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Dosimetric Comparison Between Single And Double Isocenters Volumetric Arc Therapy For Stereotactic Radiotherapy With Multiple Targets, Wai Lwin Lwin Kyaw Jan 2019

Dosimetric Comparison Between Single And Double Isocenters Volumetric Arc Therapy For Stereotactic Radiotherapy With Multiple Targets, Wai Lwin Lwin Kyaw

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this study was to evaluate the dosimetric effects between single isocenter (SI) and double isocenters (DI) VMAT SRT of multiple brain metastases. There are two parts of study, which were experimental for energy selection, technique comparison and clinical part to use appropriate technique. As the first part, three lesions with 3 cm distance apart and 1 cm size for all lesions were created as standard plan by varying energy. Twelve VMAT SRT plans by varying energy with 6 MV, 10 MV, 6 FFF and 10 FFF were planned on simulated three lesions of CT image. 18 VMAT …

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Effect Of Oxidative Stress On Microglial Activation And Iron Accumulation, Rattanakorn Suntawalimp Jan 2019

Effect Of Oxidative Stress On Microglial Activation And Iron Accumulation, Rattanakorn Suntawalimp

Chulalongkorn University Theses and Dissertations (Chula ETD)

Microglia are the glial cell in the central nervous system. They function as resident immune cells in the brain. Microglial activation was an increase in the normal aged brain and also more found in the aged brain with neurodegenerative disease. Activated microglial were found iron accumulation leading to increase ROS generation via the Fenton reaction. Therefore, the increase of microglial activation and iron accumulation is vulnerable to neuronal survival. However, the cause of iron accumulation in the activated microglia still unknown. This study hypothesized that oxidative stress which increases in the aged and neurodegenerative disease brain may cause microglial activation …

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Effect Of Jak2 Gene Mutations On Erythropoiesis Using Human Induced Pluripotent Stem Cells, Nungruthai Nilsri Jan 2019

Effect Of Jak2 Gene Mutations On Erythropoiesis Using Human Induced Pluripotent Stem Cells, Nungruthai Nilsri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Activating mutations affecting the JAK-STAT signal transduction is the genetic driver of myeloproliferative neoplasms (MPNs) which comprise polycythemia vera (PV), essential thrombocythemia (ET) and myelofibrosis. The JAK2p.V617F mutation can produce both erythrocytosis in PV and thrombocytosis in ET, while JAK2 exon 12 mutations cause only erythrocytosis. We hypothesized that these two mutations activated different intracellular signals. In this study, the induced pluripotent stem cells (iPSCs) were used to model JAK2-mutated MPNs. Normal iPSCs underwent lentiviral transduction to overexpress JAK2p.V617F or JAK2p.N542_E543del (JAK2exon12) under a doxycycline-inducible system. The modified iPSCs were differentiated into erythroid cells. Compared with JAK2V617F-iPSCS, JAK2exon12-iPSCs yielded more …

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Development Of A Clinically Feasible Translational Medical Approaches In The Treatment Of Pseudomonas Aeruginosa And Acinetobacter Baumannii Persistent Biofilm Infections., Dhammika Leshan Wannigama Jan 2019

Development Of A Clinically Feasible Translational Medical Approaches In The Treatment Of Pseudomonas Aeruginosa And Acinetobacter Baumannii Persistent Biofilm Infections., Dhammika Leshan Wannigama

Chulalongkorn University Theses and Dissertations (Chula ETD)

Despite strengthened antimicrobial therapy, biofilm infections of Pseudomonas aeruginosa and Acinetobacter baumannii are associated with poor prognosis and limited therapeutic options. Assessing antibiotics on planktonic bacteria can result in failure against biofilm infections. Currently, antibiotics to treat biofilm infections are administered empirically, usually without considering the susceptibility of the biofilm objectively before beginning treatment. For effective therapy to resolve biofilm infections it is essential to assess the efficacy of commonly used antibiotics against biofilms. Here, we offer a robust and simple assay to assess the efficacy of antibiotics against biofilms. In the present work, we carefully optimized the incubation time, …

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Alteration Levels Of Monoamine Neurotransmitter Related With Non-Motor Symptoms And Their Fluctuation Patterns During On/Off Periods In Parkinson’S Patients, Patsorn Wichit Jan 2019

Alteration Levels Of Monoamine Neurotransmitter Related With Non-Motor Symptoms And Their Fluctuation Patterns During On/Off Periods In Parkinson’S Patients, Patsorn Wichit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Parkinson’s disease (PD) is the second most common neurodegenerative disorder. This study consisted of two parts. The purpose of part I was to investigate the difference in concentrations of DA, NE, 5-HT and their metabolites (3-methoxytyramine (3-MET), homovanillic acid (HVA), normetanephrine (NM), vanillylmandelic acid (VMA) and 5-hydroxyindoleacetic acid (5-HIAA)) in peripheral body fluids between control and PD groups. In addition, the correlation between these neurotransmitter levels and NMSs were evaluated. The purpose of part II was to investigate the fluctuation of plasma DA, NE and 5-HT concentrations during medication ON/OFF periods in advanced-PD patients. In part I, the control and …

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Qualitative And Quantitative Morphological Study Of Flexor Hallucis Longus Implicated In Tendon Harvesting And Transfer, Perin Wan-Ae-Loh Jan 2019

Qualitative And Quantitative Morphological Study Of Flexor Hallucis Longus Implicated In Tendon Harvesting And Transfer, Perin Wan-Ae-Loh

Chulalongkorn University Theses and Dissertations (Chula ETD)

Flexor hallucis longus (FHL) transfer is a widely used technique for reconstruction of Achilles tendinopathies, but the complications such as neurovascular injury and functional loss of toes have been reported. This study aimed to evaluate the morphology of FHL musculotendinous junction (MTJ), location of MKH in reference to the landmarks in foot, type and morphometry of tendinous interconnection between FHL and flexor digitorum longus (FDL) tendons and FHL tendon length in single incision, double incision and minimally invasive techniques. The dissection was performed in 104 embalmed and 62 soft cadaveric feet. The result showed type 1 (87.3%) and type 3 …

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Effects Of Moderate - Intensity Exercise Training On Cardiac Angiogenic Capacity And Fibrosis In Middle-Aged And Aged Rats, Titiporn Mekrungruangwong Jan 2019

Effects Of Moderate - Intensity Exercise Training On Cardiac Angiogenic Capacity And Fibrosis In Middle-Aged And Aged Rats, Titiporn Mekrungruangwong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to investigate the protective effects of exercise training against age-induced the reduction of cardiac angiogenic capacity associated with p-Akt1, eNOS, Mdm2, p53, VEGF, and CD31 in rat hearts. Additionally, age-induced cardiac fibrosis association with TGF-β1 was also observed. Male Wistar rats were divided into five groups: Sedentary - young group (SE-Young, aged 4 months), Sedentary - middle-aged group (SE-Mid-Age, 14 months), Sedentary – aged group (SE-Age, aged 22 months), Exercise-trained middle-aged group (ET-Mid-Age, aged 14 months), and Exercise-trained -aged group (ET-Age, aged 22 months). In the SE- groups, rats were immersed individually for 30 minutes/day, 5 days/week …

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Effect Of Canagliflozin On Liver Steatosis In Obese Non Diabetic Patients With Non-Alcoholicfatty Liver Disease: A Double Blind Randomized Controlled Trial, Borwonkhun Tontivuthikul Jan 2019

Effect Of Canagliflozin On Liver Steatosis In Obese Non Diabetic Patients With Non-Alcoholicfatty Liver Disease: A Double Blind Randomized Controlled Trial, Borwonkhun Tontivuthikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objective: To demonstrate whether treatment with canagliflozin had an effect on liver steatosis in obese non-diabetic patients with NAFLD compared with the control group Methods: 82 nondiabetic patients with BMI 25-35 kg/m2 underwent 24 weeks of double blind randomized controlled trial with combined canagliflozin 100 mg daily with diet-lifestyle modification or placebo with diet-lifestyle modification (500 calories restriction and moderate intensity aerobic exercise). Primary outcome was the change in Controlled attenuation parameter (CAP) representing hepatic steatosis. Liver stiffness measurement (LSM) representing liver stiffness/fibrosis and other secondary outcomes including changes in body weight, fasting plasma glucose, lipid profile, liver function test …

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Serum Microrna Profile And Serum Neuron Specific Enolase, S-100, And Interleukin-6 Level As Biomarkers For Differentiating Acute Vertigo Between Cerebellar Or Brainstem Infarction And Peripheral Vertigo, Naruchorn Kijpaisalratana Jan 2019

Serum Microrna Profile And Serum Neuron Specific Enolase, S-100, And Interleukin-6 Level As Biomarkers For Differentiating Acute Vertigo Between Cerebellar Or Brainstem Infarction And Peripheral Vertigo, Naruchorn Kijpaisalratana

Chulalongkorn University Theses and Dissertations (Chula ETD)

Background and PurposeAcute vertigo is a common presentation of inner ear disease. However, it can also be caused by more serious conditions, especially posterior circulation stroke. Differentiation between these 2 conditions by clinical presentations and imaging studies during acute phase can be challenging. This study aims to evaluate the serum microRNA profile and serum neuron specific enolase (NSE), S-100, and interleukin-6 (IL-6) level as potential biomarkers to differentiate between patients with central vertigo due to cerebellar or brainstem infarction and peripheral vertigo.MethodsIn the discovery phase, miRNA expression profiling was performed by Nanostring nCounter Technology in serum of patients with central …

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Effect Of Zirconium On Physical Properties And Corrosion Resistance Of Chromium And Chromium Nitride Films, Kumpon Leelaruedee Jan 2019

Effect Of Zirconium On Physical Properties And Corrosion Resistance Of Chromium And Chromium Nitride Films, Kumpon Leelaruedee

Chulalongkorn University Theses and Dissertations (Chula ETD)

Corrosion is a common phenomenon which usually undergoes on metal surface leading to structural failure. Consequently, this topic has attracted many researchers to look for ways to prevent corrosion and extend lifetime of service. Coating with chromium (Cr) or chromium nitride (CrN) is the one popular technique, given the high corrosion resistance and obviating whole part replacement. However, the conventional film’s properties might not provide enough resistance for using in some severe environments. Tailoring structure to amorphous is usually considered for improve corrosion resistance. Thin amorphous featureless of CrZr-film was successfully fabricated by magnetron co-sputtering. The suitable composition (46 %at.Zr) …

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Preparation Of Ag-Cnts And Ag-Graphene Nanocomposite And Their Combination With Mno2 Bath Deposition For Flexible Supercapacitor Development., Norawich Keawploy Jan 2019

Preparation Of Ag-Cnts And Ag-Graphene Nanocomposite And Their Combination With Mno2 Bath Deposition For Flexible Supercapacitor Development., Norawich Keawploy

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, researchers have made great efforts on the development of flexible and light weight energy storage devices for their practical applications and the advancement of modern electronic devices. Owing to the promising feathers of high specific power, high rate capability, and long-term cycling life, the supercapacitors (SCs) are considered as highly suitable for various flexible applications. In general, the carbon-based nanomaterials such as carbon nanotubes and graphene nanosheets, exhibit good supercapacitor performance. Manganese dioxide (MnO2) are widely studied for pseudocapacitors owing to their high specific capacitance, high power, and energy density. Thus, MnO2 was applied to increase the supercapacitor performance …

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A Causal Model Of Sexual Abstinence In Thai Female Adolescents, La-Ongdao Wannarit Jan 2019

A Causal Model Of Sexual Abstinence In Thai Female Adolescents, La-Ongdao Wannarit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to develop and test a causal model of sexual abstinence in Thai female adolescents guiding by the Health Promotion Model of Pender, Murdaugh and, Parsons (2015). Data were collected from 654 first-year female students studying in six higher education institutions and six high-vocational schools in Thailand. Validity and reliability of 6 existing measures and 2 newly developed measures were established prior to data collection. The causal model was analyzed using Mplus program. It was found that the causal model of sexual abstinence fit the empirical data with Chi-square (χ2) = 434.344, p<0.05, degrees of freedom (df) = 173, χ2/df = 2.51, Comparative fit Index (CFI) = 0.967, Tucker-Lewis Fit Index (TLI) = 0.955, Root Mean Square Error of Approximation (RMSEA) = 0.048, Standardized Root Mean Square Residual (SRMR) = 0.041. Sixty-eight percent of the variance in Thai female adolescents’ sexual abstinence was explained by child-rearing promoting sexual abstinence, commitment to a plan of sexual abstinence, perceived benefits, perceived self-efficacy, and perceived barriers. Among these five variables, the child-rearing promoting sexual abstinence had the largest total effect on sexual abstinence, followed by commitment to a plan of sexual abstinence, perceived benefits, perceived self-efficacy, and perceived barriers, respectively. This model can be used by healthcare providers to promote sexual abstinence in Thai female adolescents.

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The Effect Of Parent Involvement-Child Behavioral Management Program Among Children With Adhd, Ubon Wannakit Jan 2019

The Effect Of Parent Involvement-Child Behavioral Management Program Among Children With Adhd, Ubon Wannakit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This quasi-experimental pretest-posttest control group design aims to examine the effectiveness of the Parent Involvement-Child Behavioral Management Program (PICBMP) in reducing symptoms among ADHD children. Sixty-four children aged 6–12 years with ADHD were randomly assigned to either the experimental or control group by using a random number table, consisting of thirty-two participants in each group. The participants in the experimental group participated in the PICBMP and usual care with medication, while those in the control group received the usual care with medication. The PICBMP based on Behaviorally-based treatment (Goodman &Scott, 1997), consists of eight weeks of behavior management which included …

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Proximal Caries Detection On Smartphone Display, Napas Lappanakokiat Jan 2019

Proximal Caries Detection On Smartphone Display, Napas Lappanakokiat

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aim of this study was to compare diagnostic accuracy in proximal caries detection between bitewing radiographs exported from PACS software and taken with a smartphone viewed in a smartphone display. A total of 200 proximal surfaces from digital bitewing radiographs were included in this study. Images of all radiographs were captured from a medical-grade and a common display by an iPhone 8 Plus and stored as JPEG files. Exported DICOM files were converted into JPEG format and transferred to the smartphone used for image capturing. Each proximal surface was rated by 7 observers with 5-point-scale. Weighted kappa test was …

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The Efficacy Of Vitamin C Oral Supplement On Wound Healing After Tooth Extraction, Nanthanut Pisalsitsakul Jan 2019

The Efficacy Of Vitamin C Oral Supplement On Wound Healing After Tooth Extraction, Nanthanut Pisalsitsakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objectives: The purpose of this study was to evaluate the effect and proper dosage of oral vitamin C supplement on post-extraction wound healing. Methods: This study was a split mouth, double-blind, randomized-controlled clinical trial of 42 patients who underwent symmetric bilateral non-infected premolars extraction. The patients were randomly divided into 3 groups (14 patients for each group); 1.placebo vs vitamin C 600 mg/d, 2.placebo vs vitamin C 1,500 mg/d and 3.vitamin C 600 mg/d vs vitamin C 1,500 mg/d. Each group was prescribed placebo and/or vitamin C three times a day for 10 days after each tooth extraction. The assessment …

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Use Of Digital Panoramic Radiographs As A Screening Tool For Diagnosis Of Osteoporosis In Thai Postmenopausal Women, Net-Nada Chongruangsri Jan 2019

Use Of Digital Panoramic Radiographs As A Screening Tool For Diagnosis Of Osteoporosis In Thai Postmenopausal Women, Net-Nada Chongruangsri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Purpose: To investigate the correlation between panoramic radiographic indices and osteoporosis, and to determine whether digital panoramic radiographs could be used as a screening tool for the diagnosis of osteoporosis in Thai postmenopausal women. Materials and Methods: A cross-sectional study of sixty Thai postmenopausal women with and without osteoporosis. The subjects were divided into three groups based on diagnosis by dual-energy X-ray absorptiometry (DXA): normal, osteopenia, and osteoporosis equally in each group. The panoramic radiographic indices measured were mental index (MI) and mandibular cortical index (MCI). Pearson’s correlation test was performed to analyze any correlation between MI, MCI, and BMD …

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Association Between Clinical Signs And Quality Of Life In Thai Patients With Oral Lichen Planus, Sasirin Yiemstan Jan 2019

Association Between Clinical Signs And Quality Of Life In Thai Patients With Oral Lichen Planus, Sasirin Yiemstan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Subjective patient’s symptoms and oral health-related quality of life (OHRQoL) were recommended to be involved in oral lichen planus (OLP) studies. Objectives: to evaluate 1) the association between OLP clinical signs and OHRQoL as well as pain perception. 2) the association between OLP pain and OHRQoL. Methods: Sixty-nine OLP or oral lichenoid drug reaction (OLDR) Thai patients were recruited. Data were collected through personal interview with the Numeric Rating Scale (NRS) and Thai version of Oral Impacts on Daily Performance (OIDP) index. OLP signs were examined in aspects of localization, type and clinical severity according to the Thongprasom sign scoring …

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Clinical Evaluation Of Two Glass Ionomer Cement Restorations Placed In Primary Molars With Atraumatic Restorative Treatment Technique: A Randomized Controlled Trial., Manarin Boonyawong Jan 2019

Clinical Evaluation Of Two Glass Ionomer Cement Restorations Placed In Primary Molars With Atraumatic Restorative Treatment Technique: A Randomized Controlled Trial., Manarin Boonyawong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objective: The purpose of this study was to compare clinical success of a novel material (silver diamine fluoride incorporated with high-viscosity glass ionomer cement (SDF-GIC)) in Class II restoration in primary molars using atraumatic restorative treatment (ART) technique at 6- and 12- month follow-up. Materials and Methods: A randomized controlled clinical trial using a parallel group design was carried out on 150 children aged 3-8 years old, from 5 public school in Samut Sakhon province, Thailand, with at least one class II cavities. They were randomly allocated to two treatment groups: ART restoration using either GIC (Fuji IX GP) or …

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Protein Expression And Inflammatory Response After Delivery Of Mrna Encoding Platelet-Derived Growth Factor-Bb In Sucrose Citrate Buffer Into Rat Gingiva, Phan Bhongsatiern Jan 2019

Protein Expression And Inflammatory Response After Delivery Of Mrna Encoding Platelet-Derived Growth Factor-Bb In Sucrose Citrate Buffer Into Rat Gingiva, Phan Bhongsatiern

Chulalongkorn University Theses and Dissertations (Chula ETD)

Messenger RNA (mRNA) has emerged as a novel therapeutic modality in medical fields, including regenerative medicine. The concept of mRNA-based therapy is to use synthesized mRNA encoding therapeutic protein delivered to target tissue. Thus, mRNA encoding growth factor could be a promising alternative to recombinant protein. Platelet-derived growth factor (PDGF) is one of most extensively studied growth factors for periodontal regeneration. To date, mRNA therapy has never been explored in the field of periodontal regeneration. The aim of the study is to examine the effect of nucleoside-modified mRNA encoding PDGF-BB on the level of PDGF-BB protein and inflammatory response at …

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The Use Of Modified Mrna Encoding Platelet-Derived Growth Factor-Bb As An Innovation In Periodontal Regeneration, Theeraphat Surisaeng Jan 2019

The Use Of Modified Mrna Encoding Platelet-Derived Growth Factor-Bb As An Innovation In Periodontal Regeneration, Theeraphat Surisaeng

Chulalongkorn University Theses and Dissertations (Chula ETD)

Since the mRNA platform has been recently introduced to several fields in medicine and the achievement of periodontal regeneration is currently unpredictable, therefore, the use of mRNA technology is a promising approach to pursue the complete periodontal regeneration. The aims of this study are to learn if mRNA encoding platelet-derived growth factor-BB (PDGF-BB) induces PDGF production in human periodontal ligament cells (PDLCs) and to investigate the effect of secreted PDGF on PDLC proliferation and promoting endothelial cell tube formation. PDLCs were obtained from extracted teeth of healthy periodontal patients. The N1-methylpseudouridine modified mRNA encoding PDGF-BB were transfected into PDLCs. The …

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Production Of Bio-Jet Fuel From Palm Fatty Acid Distillate Over Bi-Functional Copd/Hzsm-12 Catalysts, Jarujit Chaowichitra Jan 2019

Production Of Bio-Jet Fuel From Palm Fatty Acid Distillate Over Bi-Functional Copd/Hzsm-12 Catalysts, Jarujit Chaowichitra

Chulalongkorn University Theses and Dissertations (Chula ETD)

Jet fuel is one of the major products from a petroleum refinery, its combustion emissions contribute to global warming. Therefore, bio-jet fuel is introduced to solve this problem. Palm fatty acid distillate (PFAD) is an interesting feedstock for bio-jet fuel production via three reactions including deoxygenation, hydrocracking, and isomerization. In this study, the monometallic (Co and Pd) and bimetallic (CoPd and NiPd) supported on HZSM-12 zeolite with various metal loadings and bimetallic CoPd with various zeolite supports (HZSM-12, HZSM-5, and HY) were investigated in a continuous flow trickle bed reactor. The presence of bimetallic CoPd on HZSM-12 zeolite support enhanced …

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Removal Of Trace Olefins From Aromatics With Modified Usy Zeolite And Clays, Sirawit Lertprapaporn Jan 2019

Removal Of Trace Olefins From Aromatics With Modified Usy Zeolite And Clays, Sirawit Lertprapaporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Naphtha reforming is an important raw material for aromatic hydrocarbon products in petrochemical processes. However, aromatic hydrocarbon streams obtained from refinery contain unavoidable trace amounts of olefins as an impurity. The trace olefins must be removed because these undesirable olefins are harmful to the following separation processes. Alkylation reaction has been used to remove olefins with acid catalysts. In this study, clays and zeolites were screened for further modification in order to enhance the catalytic activity of olefins removal. The catalytic activity testing was studied in a batch reactor at 195 ℃ for 6 h under 12 barg. USY was …

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Combined Life Cycle Analysis And Material Flow Analysis As A Tool For End Of Life Options Of Used Lubricating Oils, Komsan Toeipomthong Jan 2019

Combined Life Cycle Analysis And Material Flow Analysis As A Tool For End Of Life Options Of Used Lubricating Oils, Komsan Toeipomthong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Used lubricating oils are one of the most significant material flows in the economy. After being used, they are typically contaminated with, e.g., heavy metals, which could harm the environments if they are treated improperly. The used oils should be properly treated by reprocessing or recycling which the recyled products can be used to subsitute the production the new product, as a result a net reduction of the environemental impacts. This study aimed to investigate the waste flow and then evaluate the environmental impacts of waste management options using the Material Flow Analysis (MFA, STAN v.2.6.801) and Life Cycle Assessment …

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Continuous Synthesis Of Biodiesel And Glycerol Ether Using Homogeneous And Heterogeneous Catalysts, Natta Rattanapanya Jan 2019

Continuous Synthesis Of Biodiesel And Glycerol Ether Using Homogeneous And Heterogeneous Catalysts, Natta Rattanapanya

Chulalongkorn University Theses and Dissertations (Chula ETD)

In our study, a mixture of p-toluenesulfonic acid and sulfuric acid (TsOH-H2SO4) as a catalyst showed a good performance in transesterification of palm oil (PO) with methanol and etherification of biodiesel with isobutylene. For biodiesel production, the catalyst noticeably accelerated the reaction faster than TsOH and H2SO4 alone and also gave up to 99.8% of the conversion. Etherification of biodiesel with isobutylene in the etherification process using isobutylene/glycerol molar ratio 6:1 at 70°C, in the period of 5 h reaction time, gave high selectivity to produce DTBG and TTBG (81.4%). Furthermore, the catalyst can be reused for 6 cycles of …

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Formaldehyde Fluorescent Sensors From 1,8-Naphthalimide Derivatives, Apicha Maharat Jan 2019

Formaldehyde Fluorescent Sensors From 1,8-Naphthalimide Derivatives, Apicha Maharat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Three derivatives of 1,8-naphthalimide were systematically designed and synthesized to investigate the effect of substitution pattern on their photophysical properties and sensing behaviors towards formaldehyde in aqueous media. The key substituents, the hydrazino (-NHNH2) and the 2-methoxyethylamino groups (-NHCH2CH2OCH3), were installed at the 4-position of 1,8-naphthalimide by a nucleophilic replacement, and at the imide position by a condensation reaction with 1,8-naphthalic anhydride precursor. All target compounds were obtained in good overall yields of 60-80%. Compounds with two hydrazine moieties (R3) showed excellent selective fluorescent responses towards formaldehyde with the 3.5-fold fluorescence enhancement in 5% aqueous acetic acid solution at 520 …

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Polyvinyl Alcohol/Starch Modified Cotton Thread For Glucose Distance-Based Colorimetric Detection, Pornchanok Punnoy Jan 2019

Polyvinyl Alcohol/Starch Modified Cotton Thread For Glucose Distance-Based Colorimetric Detection, Pornchanok Punnoy

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this thesis, polyvinyl alcohol (PVA) and starch modified cotton thread was developed as a cotton thread-based device for distance-based colorimetric detection of hydrogen peroxide (H2O2) and glucose. PVA and starch, the biocompatible polymers, were modified on a cotton thread to enhance the enzymatic stability and reagent immobilization efficiency. The colorimetric glucose detection of the device was based on a bienzymatic reaction involving glucose oxidase (GOx) and horseradish peroxidase (HRP), incorporated with potassium iodide (KI) as an indicator, which was oxidized by H2O2 to provide blue-black color band of an iodine–starch complex. The length of color band on the cotton …

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Continuous Flow Selective Hydrogenation Of 5-Hydroxymethylfurfural To 2.5-Dimethylfuran Using Pd-Cu/Reduced Graphene Oxde Catalysts, Sareena Mhadmhan Jan 2019

Continuous Flow Selective Hydrogenation Of 5-Hydroxymethylfurfural To 2.5-Dimethylfuran Using Pd-Cu/Reduced Graphene Oxde Catalysts, Sareena Mhadmhan

Chulalongkorn University Theses and Dissertations (Chula ETD)

2,5-Dimethylfuran (DMF) has been considered a promising biofuel, potentially derived from biomass. There have been various reports on DMF production from hydrogenation of 5-hydroxymethylfurfural (HMF). However, most reports employed high hydrogen pressure, long reaction times, and reactions under batch reactor. In this study, Pd-Cu bimetallic catalysts incorporated on reduced graphene oxide (RGO) were used for hydrogenation of HMF to DMF using 2-propanol as hydrogen donor under continuous flow system. Synthesized catalysts were characterized by N2 physisorption, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and temperature programmed reduction of hydrogen …

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