Chiang Mai, Thailand
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Inyawilert K.,Chiang Mai UniversityChiang Mai | Wisitsoraat A.,National Science and Technology Development Agency | Tuantranont A.,National Science and Technology Development Agency | Phanichphant S.,Chiang Mai UniversityChiang Mai | Liewhiran C.,Chiang Mai UniversityChiang Mai
Sensors and Actuators, B: Chemical | Year: 2017

In this research, SnO2 nanoparticles doped with 0.1–2 wt% rhodium (Rh) were synthesized by flame spray pyrolysis and systematically investigated for H2-sensing applications. From X-ray and electron microscopic characterizations, SnO2 nanostructures exhibited spheroidal morphology with polycrystalline tetragonal SnO2 phase and Rh might form solid solution with SnO2 lattice. The sensing films were prepared by spin coating technique and their gas-sensing performances were studied at the operating temperatures ranging from 100 to 350 °C in dry air. Gas-sensing measurements showed that SnO2 sensing films with the optimal Rh-doping level of 0.2 wt% exhibited an ultra-high response of ∼22,170, which was more than three orders of magnitude higher than that of undoped one, and a short response time of 6 s towards 30,000 ppm H2 at an optimum operating temperature of 300 °C. In addition, the optimal Rh-doped SnO2 sensor displayed high H2 selectivity against NO2, SO2, C2H4, C3H6O, CH4, H2S and CO. Thus, Rh-doped SnO2 nanoparticulate thick films are promising candidates for H2-sensing applications. © 2016 Elsevier B.V.

Rapeekan J.,Chiang Mai UniversityChiang Mai | Songtipya P.,Prince of Songkla University | Lee D.S.,Sungkyunkwan University | Manokruang K.,Chiang Mai UniversityChiang Mai
Colloids and Surfaces B: Biointerfaces | Year: 2016

Injectable hydrogels are alternative materials for drug and protein delivery in biomedical applications, which can potentially eliminate the need of surgical implantation in the treatment procedures. Prior to administration, such hydrogels, in a liquid state, must demonstrate good interactions with the incorporated molecules to maintain the sustain release of active agents and to avoid unappreciative burst release. The injectable hydrogels derived from BSA-pH/temperature responsive poly(amino urethane) conjugates have been reported to demonstrated good sustainability for delivery of lysozyme, both in vitro and in vivo. However, the interactions between such conjugates and the loading lysozyme were not fully understood. In this present work, we reported the binding interactions between the studied complex systems, BSA-pH/temperature responsive poly(amino urethane) conjugates (CONJ1 and CONJ2) and lysozyme. Fluorescence spectroscopy in a combination with thermodynamic analysis exhibited that the binding between the conjugates and lysozyme occurred through static quenching and the binding interactions in the complexes were mainly van der Waals forces and hydrogen bonds. The binding constants (KA) determined at 300, 308 and 318 K of CONJ1 to lysozyme were 7.96 × 104, 6.45 × 104 and 3.20 × 104 M−1, respectively and those of CONJ2 to lysozyme were 2.63 × 104, 2.53 × 104 and 1.19 × 104 M−1, respectively. FTIR analysis showed that the complexes between the conjugates and lysozyme demonstrated sufficiently small deviation in the conformational structures from the native lysozyme. In addition, the morphology revealed by TEM and AFM imaging portrayed the behavior of complex formation in such a way that the conjugates, before complex formation, displayed the core-shell structures. After the complex formation, a number of lysozyme particles were noticeably entrapped as if they penetrated into the preformed core-shell conjugates. © 2016 Elsevier B.V.

Samerjai C.,Chiang Mai UniversityChiang Mai | Sanit S.,Chiang Mai UniversityChiang Mai | Sukontason K.,Chiang Mai UniversityChiang Mai | Morakote N.,Chiang Mai UniversityChiang Mai | And 3 more authors.
Acta Tropica | Year: 2016

The flesh flies are medically-important because the larvae found in the human corpses can provide evidence in forensic investigations through larva identification and their developmental rate. Firstly, we thoroughly described the larval morphology of Boettcherisca nathani and Lioproctia pattoni, using scanning electron microscopy (SEM). The third instar of the two species differed markedly in two characters: (1) spines between the prothorax and mesothorax−B. nathani has more or less slender triangular spines, with those at the posterior region more slender than the anterior region; whereas L. pattoni has stout triangular spines with one or two tips anteriorly, with smaller and tapered triangular shape, grouped two to four laterally in the posterior end, and (2) morphology of the peristigmatic tufts at the posterior spiracle−B. nathani has extensively branched long, fine hairs, whereas tufts in L. pattoni have moderately branched long, fine hairs. The anterior spiracle displayed similarity; B. nathani has two irregular rows of 21–27 papillae, while L. pattoni has a single irregular row of 20–28 papillae. Secondly, we use light microscopy to compare morphology of the third instar of the two species and additional three species, i.e., Bercaea africa, Parasarcophaga dux and Liopygia ruficornis. Particular attention was paid to the features of anterior spiracle, spines between prothorax and mesothorax and posterior spiracle. These results are useful in species identification and estimation of age of larvae found associated with corpses. © 2016 Elsevier B.V.

Phanichphant S.,Chiang Mai UniversityChiang Mai | Nakaruk A.,Naresuan UniversityPhitsanulok | Channei D.,Naresuan UniversityPhitsanulok
Applied Surface Science | Year: 2016

In this study, CeO2 photocatalyst was modified by composite with SiO2 to increase efficiency and improve photocatalytic activity. The as-prepared SiO2 particles have been incorporated into the precursor mixture of CeO2 by homogeneous precipitation and subsequent calcination process. The phase compositions of CeO2 before and after compositing with SiO2 were identified by X-ray diffraction (XRD). The morphology and particle size of CeO2/SiO2 composite was analyzed by high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). The results showed SiO2 spheres with the particle size approximately 100–120 nm, and a uniform layer of CeO2 nanoparticles with a diameter of about 5–7 nm that were fully composite to the surfaces of SiO2. The X-ray photoelectron spectroscopy (XPS) technique was carried out in order to characterize the change in valence state and composite characteristic by shifted peaks of binding energies. The photocatalytic activity was studied through the degradation of Rhodamine B in aqueous solution under visible light exposure. The highest photocatalytic efficiency of CeO2/SiO2 composite was also obtained. To explain the high photocatalytic efficiency of CeO2/SiO2 composite, the proposed mechanism involves the high surface properties of the CeO2/SiO2 composite, as measured by Brunauer-Emmett-Teller (BET) method. © 2016 Elsevier B.V.

Pientong C.,Khon Kaen UniversityKhon Kaen | Wongwarissara P.,Khon Kaen UniversityKhon Kaen | Ekalaksananan T.,Khon Kaen UniversityKhon Kaen | Swangphon P.,Khon Kaen UniversityKhon Kaen | And 5 more authors.
Virology Journal | Year: 2013

Background: The variation of human papillomavirus (HPV) genes or HPV variants demonstrates different risks of cervical cancer. Mutation in the long control region (LCR) at YY1-motifs is one of the mechanisms for enhancing viral oncogene expression during the course of cancer cell progression. In Thai women, cervical cancers are almost always associated with HPV16 variant sub-lineage Asian (HPV16As); however, the mechanism involved remains elusive. The aim of this study was to understand further the oncogenic potential of HPV16As. Methods: A total of 82 HPV16-positive specimens from Thai women were selected from formalin-fixed paraffin-embedded cervical tissues, and the full length E6 gene of each specimen was amplified and sequenced. LCRs of the HPV16As-positive cases were amplified and sequenced to analyze their polymorphisms. Transcriptional activities of the HPV16As LCRs were then compared with sub-lineage European (EUR), sub-lineage Asian-American 1 (AA1) and HPV16 prototype by insertion of the LCRs into the pGL3-Basic vector. Results: The HPV16 DNA sequences were classified as HPV16 prototype (18.3%), Asian (As, 61%), Asian American-1 (AA1, 8.5%), European (EUR, 7.3%), Asian African-2 (AFR2, 3.7%) and Java-135C (J135C, 1.2%). The prevalence of HPV16As was 30% in low-grade squamous intraepithelial lesion (LSIL), while that in high-grade squamous intraepithelial lesion (HSIL) and squamous cell cervical carcinoma (SCC) were 63.9% and 66.7%, respectively, which demonstrates a significant association of HPV16As with the disease severity. LCR polymorphisms from 43 HPV16As positive cases were analyzed by PCR-sequencing. Thirty-eight nucleotide variation positions spanned nucleotide positions 7157-82. Ten new mutations found in the HPV16As LCRs were located predominantly at the enhancer and proximal to the 3'-end of the early promoter. The LCRs of the common HPV16As, EUR and AA1 showed 5, 13 and 23-fold higher activity than the HPV16 prototype LCR, while those of the new nucleotide variations of As showed 19 (As-sv1) and 30 (As-sv14) -fold higher activity than the HPV16 prototype. Conclusions: HPV16As DNA sequence variation, especially at the proximal to early promoter in the LCR, enhances transcriptional activity. This could be one of the possible mechanisms for HPV16As-associated cervical cancer development. © 2013 Pientong et al; licensee BioMed Central Ltd.

Sruamsiri K.,Chiang Mai UniversityChiang Mai | Chenthanakij B.,Chiang Mai UniversityChiang Mai | Wittayachamnankul B.,Chiang Mai UniversityChiang Mai
Journal of the Medical Association of Thailand | Year: 2014

Background: Management of patients with severe hypertension without progressive target organ damage remains controversial. Some guidelines mentioned oral anti-hypertensive medication as a treatment to reduce blood pressure in the emergency department, while others recommended against such treatment.Objective: To review the management of patients with severe hypertension without progressive target organ damage in the emergency department, Maharaj Nakorn Chiang Mai hospital.Material and Method: In a retrospective descriptive analysis study, medical records of adult patients diagnosed with severe hypertension without progressive target organ damage between January 2011 and December 2012 were reviewed. Patient demographics, data on management including investigation sent and treatment given were collected. Statistical analysis was done by using descriptive statistics and Kruskal-Wallis one-way analysis of variance test.Results: One hundred fifty one medical records were reviewed. Four oral anti-hypertensive medication were used to reduce blood pressure, Amlodipine, Captopril, Hydralazine, and Nifedipine. There were no significant difference between each medication in terms of their effect on blood pressure reduction (p = 0.513). No side effect or other complications from the use of oral anti-hypertensive medication were recorded.Conclusion: The choice of medication used for the treatment of hypertensive urgency ranged from Amlodipine, Captopril, Hydralazine, and Nifedipine, which varied in dosage. However, their efficacies were the same when compared with each other, and none produced any notable side effects. © 2014, Medical Association of Thailand. All rights reserved.

Kabcum S.,Chiang Mai UniversityChiang Mai | Tammanoon N.,Chiang Mai UniversityChiang Mai | Wisitsoraat A.,National Science and Technology Development Agency | Tuantranont A.,National Science and Technology Development Agency | And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2016

In this work, Mo-doped SnO2 nanoparticulate sensing films were fabricated by flame spray pyrolysis (FSP) and spin-coating processes with varying Mo-doping concentrations (0–2 wt%) and numbers of spin-coating cycles (1–5). Structural characterizations by electron microscopy and X-ray analysis suggested that Mo atoms were substitutionally doped in polycrystalline SnO2 nanoparticles at low Mo concentrations (<1 wt%) but then segregated as secondary MoO3 crystallites at high Mo levels (1–2 wt%). In addition, the incorporation of Mo resulted in the reduction of size and the increase of surface area of SnO2 nanoparticles. The gas-sensing properties of sensors were investigated towards H2S, NO2, NH3, H2 and CO at the working temperature ranging from 150 °C to 350 °C. The results showed that the moderate Mo-doping level of 0.5 wt% and the high number of spin-coating cycles of 4 led to the optimal enhancement of H2S response. The optimal Mo concentration could be correlated to the highest doping level that did not induce secondary MoO3 crystallites. In particular, the 0.5 wt% Mo-doped SnO2 sensor prepared with 4 spin-coating cycles exhibited a high response of ∼105 and a short response time of ∼5 s–10 ppm H2S at an optimal working temperature of 250 °C. Furthermore, the optimal sensor displayed good H2S selectivity against NO2, NH3, H2 and CO. Therefore, the flame-spray-made Mo-doped SnO2 thick film sensor is a promising candidate for sensitive and selective detection of H2S at a threshold limit value (TLV) of lower than 10 ppm and may be useful for general industrial applications. © 2016 Elsevier B.V.

Jarulertwathana B.,Chiang Mai University | Sarakonsri T.,Chiang Mai University | Sarakonsri T.,Chiang Mai UniversityChiang Mai
Journal of Ceramic Processing Research | Year: 2014

Silica/copper (SiO2/Cu) composites were prepared in nano-dimensions for use as anode materials in lithium-ion batteries. Modified Stöber and microwave-assisted methods were used to prepare of SiO2 and Cu, respectively. The composites were prepared with different tetraethyl orthosilicate (TEOS) concentrations and mole ratios of TEOS to Cu2+ reactants. Cu was observed as the main phase in the products, which agglomerated into large particles, with some of them dispersed on the SiO2 particles. SiO2 appeared in the composites was amorphous phase and spherical in shape. Decreasing the TEOS concentration decreased the size of the SiO2. © 2014, Journal of Ceramic Processing Research. All Rights Reserved.

Naksuriya O.,Chiang Mai University | Shi Y.,University Utrecht | Van Nostrum C.F.,University Utrecht | Anuchapreeda S.,Chiang Mai UniversityChiang Mai | And 2 more authors.
European Journal of Pharmaceutics and Biopharmaceutics | Year: 2015

Abstract Curcumin (CM) has been reported as a potential anticancer agent. However, its pharmaceutical applications as therapeutic agent are hampered because of its poor aqueous solubility. The present study explores the advantages of polymeric micelles composed of block copolymers of methoxypoly(ethylene glycol) (mPEG) and N-(2-hydroxypropyl) methacrylamide (HPMA) modified with monolactate, dilactate and benzoyl side groups to enhance CM solubility and inhibitory activity against cancer cells. Amphiphilic block copolymers, ω-methoxypoly(ethylene glycol)-b-(N-(2-benzoyloxypropyl) methacrylamide) (PEG-HPMA-Bz) were synthesized and characterized by 1H NMR and GPC. One polymer with a molecular weight of 28,000 Da was used to formulate CM and compared with other aromatic substituted polymers. CM was loaded by a fast heating method (PEG-HPMA-DL and PEG-HPMA-Bz-L) and a nanoprecipitation method (PEG-HPMA-Bz). Physicochemical characteristics and cytotoxicity/cytocompatibility of the CM loaded polymeric micelles were evaluated. It was found that HPMA-based polymeric micelles significantly enhanced the solubility of CM. The PEG-HPMA-Bz micelles showed the best solubilization properties. CM loaded polymeric micelles showed sustained release of the loading CM for more than 20 days. All of CM loaded polymeric micelles formulations showed a significantly potent cytotoxic effect against three cancer cell lines. HPMA-based polymeric micelles are therefore promising nanodelivery systems of CM for cancer therapy. © 2015 Elsevier B.V.

Laokuldilok N.,Chiang Mai UniversityChiang Mai | Thakeow P.,Chiang Mai UniversityChiang Mai | Kopermsub P.,National Science and Technology Development Agency | Utama-Ang N.,Chiang Mai UniversityChiang Mai
Food Chemistry | Year: 2016

The aim of this study was to evaluate the odour masking property, encapsulation efficiency and physicochemical properties of turmeric extract prepared by a binary blend of wall materials, i.e. brown rice flour (BRF) and beta-cyclodextrin (β-CD). Response surface methodology was applied to investigate the effect of encapsulation processing variables, including core loading mass (5-25%) and β-CD (5-20%) concentration on product recovery, moisture content, hygroscopicity, curcuminoids encapsulation and volatile release. To investigate odour masking properties of a wall material combination, volatiles in headspace were monitored by GC-MS using ar-turmerone and 2-methyl-4-vinylguaiacol as marker compounds to represent turmeric extract. The obtained results revealed an optimal encapsulation process was 5% of core loading mass with addition 20 g/L of β-CD, since it enabled high curcuminoids encapsulation with low volatile release, moisture content and hygroscopicity. Turmeric powder with reduced odour can be used as a nutrient supplement or natural colorant for food products. © 2015 Elsevier Ltd.

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