Image-Based Brachytherapy in Cervical Cancer: Review and Experiences in Faculty of Medicine, Chiang Mai University

Cervical cancer is the one of the most common cancer in female patients inThailand. Radiotherapy has the role for the treatment of cervical cancer by postoperative, radical and palliative treatments. For radical radiotherapy, the combination of external beam radiation therapy and brachytherapy will be used to increase the tumor dose to curative goal. With the new development of medical images (Computed tomography (CT), Magnetic Resonance Imaging (MRI) or Ultrasonography (US)), the treatment with brachytherapy will be developed from point-based to volume-based concepts. Many studies reported the benefit of image-based brachytherapy over conventional brachytherapy and clinical benefit of using image-based brachytherapy in the treatment of cervical cancer.

Treatment Results of Adjuvant Brachytherapy as Monotherapy in Endometrial Cancer: A Retrospective Study from Faculty of Medicine, Chiang Mai University

Purpose: To report the retrospective study of using intravaginal brachytherapy as adjuvant monotherapy for endometrial cancer. Materials and Methods: From 2001-2009, 47 patients who received completely surgical staging for endometrial carcinoma and were designed by multidisciplinary team were enrolled. All patients received intravaginal brachytherapy (IVBT) with the dose of 5.5 - 7 Gy in 2 - 6 fractions. The treatment results and late toxicities were evaluated and recorded. Results: At the median follow-up time of 44 months, the local control, disease-free survival, metastasis-free survival and overall survival rates were 100%, 97.9%, 97.9% and, 97.9%, respectively. Only age showed the statistical significance with the p-value of 0.046. Two patients (4.3%) developed late genitourinary toxicity. Conclusion: The using of adjuvant IVBT as monotherapy for endometrial carcinoma is feasible.

Adjuvant External Beam Radiotherapy ±Brachytherapy in Endometrial Cancer: A Retrospective Study from Faculty of Medicine, Chiang Mai University

Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal brachytherapy (IVBT) as adjuvant treatment for endometrial cancer. Materials and Methods: From 2001-2009, 152 patients received complete surgical staging for endometrial carcinoma and were designed by a multidisciplinary team to receive EBRT ± IVBT. The treatment results and late toxicities were evaluated and recorded. Results: At the median follow-up time of 43 months, the disease-free survival, metastasis-free survival and overall survival rates were 96.9%, 96.9% and 96.9%, respectively. Stage and age showed the statistical significance with the p-value of less than 0.001. From five to ten percent of patients developed Grades 1-2 late gastrointestinal and genitourinary toxicities, respectively. Conclusion: The using of adjuvant EBRT ± IVBT for endometrial?carcinoma yielded treatment results and acceptable toxicities.

生如夏花之绚烂,逝如秋叶之静美——记泰国蜂学专家Panuwan教授

一、Panuwan教授生平简介Panuwan Chantawannakul(1974-2022),出生于泰国清迈,1995博士毕业于英国卡迪夫大学(Cardiff University),获微生物学博士学位。生前任清迈大学理学院生物学系教授,博士生导师。在蜜蜂病理、微生物多样性和天然产物等领域发表了一系列具有国际影响力的文章。Panuwan教授学术背景扎实,自1991年赴英国攻读博士开始即从事蜜蜂科学研究,博士毕业后,先后多次前往日本、英国、德国、比利时、瑞士、美国等国进行博士后训练或访学,与美国农业部蜜蜂研究室、瑞士伯尔尼大学、日本国家畜牧业和草原科学研究所、中国农业科学院蜜蜂研究所等机构建立了很好的合作关系。

不同表观温度水平下大气细颗粒物暴露对人群非意外死亡的影响

目的:评估空气动力学直径≤2.5μm的大气细颗粒物(particulate matter, PM_(2.5))暴露在不同表观温度水平下对人群非意外死亡的影响,进一步探究表观温度的效应修饰作用。方法:采用时间序列研究,选取中国的天津和宁波两个城市、泰国的曼谷和清迈两个城市作为研究地点,以表观温度作为温度的暴露指标,通过对阈值温度的定量估计,根据阈值温度对应的污染物水平进行分层,采用广义泊松(Poisson)相加模型来评估不同温度水平下PM_(2.5)暴露与人群非意外死亡之间的关联。结果:天津、宁波、曼谷和清迈4个亚洲城市在研究期间PM_(2.5)的平均浓度分别为(73.6±35.6)、(48.0±32.1)、(33.5±28.4)和(32.6±28.6)μg/m~3,日均非意外死亡人数分别为148、57、28和8人。广义泊松相加模型分析显示,天津市滞后0 d的PM_(2.5)浓度每升高10μg/m^(3),非意外死亡人数增加0.43%(95%CI:0.33%~0.54%);宁波市滞后2 d的PM_(2.5)每升高10μg/m^(3),非意外死亡人数增加0.27%(95%CI:0.08%~0.46%)。天津市在高温水平下,空气污染的死亡影响更大,而宁波和曼谷在低温时PM_(2.5)的死亡效应更明显。不同温度水平共污染物模型中,PM_(2.5)的死亡效应相对稳健。结论:大气细颗粒物暴露对人群非意外死亡有不利影响,应进一步注意控制空气污染,表观温度可能对PM_(2.5)的死亡影响产生效应修饰作用,且在不同温度带的效应有所差异,应根据地区差异建立保护性政策,同时在探究空气污染和气候变化的相互影响方面应予更多关注。

Abiotic and Biotic Factors Controlling Grain Aroma along Value Chain of Fragrant Rice:A Review

The aroma of fragrant rice is one of the grain quality attributes that significantly influenceconsumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) isrecognized as a key component of the aroma in fragrant rice. The variation in grain 2AP content amongvarious fragrant rice varieties is associated with the expression of the badh2 gene, with 19 alleles havingbeen identified so far. The grain 2AP content is strongly influenced by environmental and managementfactors during cultivation as well as post-harvest conditions. This review pinpointed the major abiotic andbiotic factors that control grain 2AP content. Abiotic factors refer to water, temperature, light quality,fertilizer application (both macro- and micro-nutrients), and soil properties, including salinity, while bioticfactors include microorganisms that produce aromatic compounds, thus influencing the grain aroma infragrant rice. Post-harvest management, including storage and drying conditions, can significantly impactthe grain 2AP content, and proper post-harvest conditions can intensify the grain aroma. This reviewsuggests that there are rice varieties that can serve as potential sources of genetic material for breedingrice varieties with high grain aroma content. It offers an overview of recent research on the major factorsaffecting the aroma content in fragrant rice. This knowledge will facilitate further research on theproduction of high-quality rice to meet the demands of farmers and consumers.

Determination of Material Parameters of EVA Foam under Uniaxial Compressive Testing Using Hyperelastic Models

The objective of this research was to determine the mechanical parameter from EVA foam and also investigate its behavior by using Blatz-Ko,Neo-Hookean,Mooney model and experimental test.The physical characteristic of EVA foam was also evaluated by scanning electron microscopy(SEM).The results show that Blatz-Ko and Neo-Hookean model can fit the curve at 5%and 8%strain,respectively.The Mooney model can fit the curve at 50%strain.The modulus of rigidity evaluated from Mooney model is 0.0814±0.0027 MPa.The structure of EVA foam from SEM image shows that EVA structure is a closed cell with homogeneous porous structure.From the result,it is found that Mooney model can adjust the data better than other models.This model can be applied for mechanical response prediction of EVA foam and also for reference value in engineering application.

Early endotracheal intubation is not associated with the rate of return of spontaneous circulation following cardiac arrest at the emergency department:an exploratory analysis

Cardiac arrest poses a significant global public health challenge,manifesting in approximately 550,000 cases annually within the United States.[1]In-hospital cardiac arrest(IHCA)is commonly attributed to airways and respiratory issues.[2]Recommendations emphasize the expertise of responders in airway management.[3]Various options exist,such as chest compression-only cardiopulmonary resuscitation(CPR),bag-mask ventilation(BMV),and advanced airways.The BMV and advanced airways are not deemed equivalent or superior based on previous evidence.[4]Achieving consistency in choosing and timing the optimal airway approach during IHCA is crucial.The current American Heart Association guidelines suggest an advanced airway strategy when endotracheal intubation(ETI)success rates are high,but the optimal time for advanced airway management remains unclear.[5]Wong et al[6]revealed that survival improved by less than 5 min with advanced airway management.According to a subgroup analysis of IHCA patients in emergency departments(EDs),early intubation was associated with a 1.5-fold greater rate of return of spontaneous circulation(ROSC)than in other locations.[7]ED patients’constant monitoring and immediate management,with readily available intubation equipment,enhance early intubation and survival rates.[6]Nonetheless,IHCA patients intubated within the first 15 min had a lower ROSC rate.

Abdominal cocoon syndrome-a rare culprit behind small bowel ischemia and obstruction:Three case reports

BACKGROUND Abdominal cocoon syndrome(ACS)represents a category within sclerosing encapsulating peritonitis,characterized by the encapsulation of internal organs with a fibrous,cocoon-like membrane of unknown origin,resulting in bowel obstruction and ischemia.Diagnosing this condition before surgery poses a cha-llenge,often requiring confirmation during laparotomy.In this context,we depict three instances of ACS:One linked to intestinal obstruction,the second exclu-sively manifesting as intestinal ischemia without any obstruction,and the final case involving a discrepancy between the radiologist and the surgeon.CASE SUMMARY Three male patients,aged 53,58,and 61 originating from Northern Thailand,arrived at our medical facility complaining of abdominal pain without any prior surgeries.Their vital signs remained stable during the assessment.The diagnosis of abdominal cocoon was confirmed through abdominal computed tomography(CT)before surgery.In the first case,the CT scan revealed capsules around the small bowel loops,showing no enhancement,along with mesenteric congestion affecting both small and large bowel loops,without a clear obstruction.The second case showed intestinal obstruction due to an encapsulated capsule on the CT scan.In the final case,a patient presented with recurring abdominal pain.Initially,the radiologist suspected enteritis as the cause after the CT scan.However,a detailed review led the surgeon to suspect encapsulating peritoneal sclerosis(ACS)and subsequently perform surgery.The surgical procedure involved complete removal of the encapsulating structure,resection of a portion of the small bowel,and end-to-end anastomosis.No complications occurred during surgery,and the patients had a smooth recovery after surgery,eventually discharged in good health.The histopathological examination of the fibrous membrane(cocoon)across all cases consistently revealed the presence of fibro-collagenous tissue,without any indications of malignancy.CONCLUSION Individuals diagnosed with abdominal cocoons commonly manifest vague symptoms of abdominal discomfort.An elevated degree of clinical suspicion,combined with the application of appropriate radiological evaluations,markedly improves the probability of identifying the abdominal cocoon before surgical intervention.In cases of complete bowel obstruction or ischemia,the established norm is the comprehensive removal of the peritoneal sac as part of standard care.Resection with intestinal anastomosis is advised solely when ischemia and gangrene have been confirmed.

Ancylostoma ceylanicum and other zoonotic canine hookworms:neglected public and animal health risks in the Asia-Pacific region

Zoonotic hookworm infections remain a significant public health problem,causing nearly 500 milion cases globally and approximately four million disability-adjusted life years lost annually.More than one-fth of these cases are attrib-uted to Ancylostoma ceylanicum,an emerging zoonotic health issue in the Asia-Pacific region.This review presents key research gaps regarding the epidemiology,diagnosis,control,prevention and elimination of A.ceylanicum and other canine zoonotic hookworms as neglected health threats.A.ceylanicum is the second most prevalent human hook-worm in the region;it is the most common hookworm among dogs and cats-reservoirs of zoonotic infections.Previous population genetic and phylogenetic analyses revealed that A.ceylanicum has three possible transmis-sion dynamics:zoonotic,animal-only,and human-only pathways.The actual burden of zoonotic ancylostomiasis in most endemic countries remains unknown due to the use of parasitological techniques(e.g.,Kato-Katz thick smear and floatation techniques)that have reduced diagnostic performance and do not allow accurate species identifica-tion in helminth surveys.The emergence of benzimidazole resistance in soil-transmitted helminths(STHs),includ-ing hookworms,is a concern due to the protracted implementation of mass drug administration(MDA).Resistance is conferred by single nucleotide polymorphisms(SNPs)that occur in theβ-tubulin isotype 1 gene.These mutations have been reported in drug-resistant A.caninum but have not been found in A.ceylanicum in the field.A.ceylanicum remains understudied in the Asia-Pacific region.The zoonotic nature of the parasite warrants investigation of its occur-rence in human and animal reservoir hosts to understand the dynamics of zoonotic transmission in different endemic foci.The detection of benzimidazole resistance-associated SNPs in zoonotic hookworms from Asia-Pacific countries has yet to be thoroughly explored.Considering the high level of hookworm endemicity in the region,the circulation of resistant isolates between humans and animals potentially presents a significant One Health threat that can under-mine current MDA and proposed animal deworming-based control efforts.

On the Dissemination and Acceptance of Dongpo Culture in the UK and the US

This study delves into the intricate dissemination and acceptance of Dongpo Culture,epitomized by Su Shi,in the UK and the US,aiming to bolster the global recognition of Chinese literary and cultural values and advance the national strategy of“Going Out”.Su Shi’s multifaceted contributions—spanning literature,philosophy,calligraphy,and art—serve as a pinnacle of Northern Song Dynasty culture.This research evaluates the varied translations,monographs,biographies,journal articles,and doctoral dissertations about Su Shi in these Western nations,using literature analysis,typical analysis,and comparative methods.The findings reveal a robust interest in Su Shi studies in the US,marked by a proliferation of scholarly works and translations across diverse disciplines,such as literature,art,and aesthetics,establishing the US as a leading center for Dongpo Culture studies.Conversely,the UK,despite its early engagement,shows limited scholarly outputs and significant research papers on the subject.By examining Dongpo Culture’s overseas communication path and influence paradigm,this paper seeks to enhance China’s cultural soft power and self-confidence.It underscores the vital role of international cultural exchange in constructing a positive image of China’s national identity,facilitating its peaceful rise,and providing strategic insights for the global promotion of Chinese culture.

Recent progress in two-dimensional metallenes and their potential application as electrocatalyst

In this article,we looked at metallenes,a novel class of two-dimensional(2D)metals that are attracting interest in the energy and catalysis sectors.Catalysis is one area where their exceptional physicochemical and electrical characteristics might be useful.Metallenes are unique because they include several metal atoms that are not in a coordinated bond.This makes them more active and improves their atomic uti-lization,which in turn increases their catalytic potential.This article delves into the potential of two-dimensional metals as electrocatalysts for carbon dioxide reduction,fuel oxidation,oxygen evolution,and oxygen reduction reactions in the context of sustainable energy conversion.Owing to the exception-ally high surface-to-volume ratio,large surface area as well as their optimized atomic use efficiency,2D materials defined by atomic layers are crucial for surface-related sustainable energy applications.Due to its exceptional properties,such as high conductivity and the ability to enhance the exposure of active metal sites,2D metallenes have recently attracted a lot of interest for use in catalysis,electronics,and energy-related applications.With their highly mobility,adjustable surface states,and electrical struc-tures that can be fine-tuned,2D metallenes are promising nanostructure materials for use in energy con-version with the sustainable applications.

Validity,Reliability,and Measurement Invariance of the Thai Smartphone Application-Based Addiction Scale and Bergen Social Media Addiction Scale

Background:In recent years,there has been increased research interest in both smartphone addiction and social media addiction as well as the development of psychometric instruments to assess these constructs.However,there is a lack of psychometric evaluation for instruments assessing smartphone addiction and social media addiction in Thailand.The present study evaluated the psychometric properties and gender measurement invariance of the Thai version of the Smartphone Application-Based Addiction Scale(SABAS)and Bergen Social Media Addiction Scale(BSMAS).Method:A total of 801 Thai university students participated in an online survey from January 2022 to July 2022 which included demographic information,SABAS,BSMAS,and the Internet Gaming Disorder Scale-Short Form(IGDS9-SF).Results:Confirmatory Factor Analyses(CFAs)found that both the SABAS and BSMAS had a one-factor structure.Findings demonstrated adequate psychometric properties of both instruments and also supported measurement invariance across genders.Moreover,scores on the SABAS and BSMAS were correlated with scores on the IGDS9-SF.Conclusion:The results indicated that the SABAS and BSMAS are useful psychometric instruments for assessing the risk of smartphone addiction and social media addiction among Thai young adults.

Epidemiology of cercarial stage of trematodes in freshwater snails from Chiang Mai province,Thailand

Objective:To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province,Thailand.Methods:The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012.The prevalence of cercarial infection in snails was investigated using the crushing method.The drawing was done with the help of a camera lucida for the morphological study.Results:A total of 2479 snail individuals were collected and classified into 7 families,11 genera,and 14 species,Among them,8 snails species were found to be infected with an overall prevalence of 17.27%(428/2479),which infected with nine groups of cercariae;gymnocephalous cercaria,strigea cercaria,megalurous cercaria,monostome cercaria,parapleurolophocercous cercaria(Haplorchis cercaria),pleurolophocercous cercaria,furcocercous cercaria(Transversotrema cercaria),xiphidiocercaria,and virgulate cercaria.The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails(64.25%).Conclusions:The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals.This work will provide new information on both the distribution and first intermediate host of trematodes.

Prevalence of infection and molecular confirmation by using ITS-2 region of Fasciola gigantica found in domestic cattle from Chiang Mai province,Thailand

Objective:To investigate the infection of Fasciola gigantka(F.gigantka)in domestic cattle from Chiang Mai province and molecular confirmation using ITS-2 region.Methods:The liver and gall bladder of Bubalus bubalis(B.bubalis)and Bos taurus(B.taunts)from slaughterhouses were examined adult worms and prevalence investigation.The species confirmation with phylogenetic analysis using ITS-2 sequences was performed by maximum likelihood and UPGMA methods.Results:The total prevalences of infection in B.bubalis and Bubalus taurus(B.taurus)were67.27%and 52.94%respectively.The respective prevalence in both B.bubalis and B.taurus were acquired from Doi-Saket,Muang,and Sanpatong districts,with 81.25%,62.50%and 60.00%for B.bubalis and 62.50%,50.00%and 47.06%for Bos taunts respectively.The species confirmation of F.gigantka and some related species by basing on maximum likelihood and UPGMA methods used,4 groups of trematodes were generated,first F.gigantka group including specimen of Chiang Mai,second 2 samples of F.hepatica,third group of 3 rumen flukes;Orthocoelium streptocoelium,F.elongatus and Paramphistomum epliclitum and fourth group of 3 minute intestinal flukes:Haplorchis taichui,Stellantchasmu falcatus.Haplorchoides sp.and liver fluke;Opisthorchis civerrini respectively.Conclusions:These results can be confirmed the Giant liver fluke which mainly caused fascioliasis in Chiang Mai was identified as F.gigantka and specimens were the same as those of F.gigantka recorded in olher different countries.Nucleotide sequence of ITS-2 region has been proven as effective diagnostic tool for the identification of F.gigantka.

Effects of muscle fiber orientation to main magnetic field on muscle metabolite profiles for magnetic resonance spectroscopy acquisition

BACKGROUND Proton magnetic resonance spectroscopy(~1H MRS) is a technique widely used for investigating metabolites in humans. Lipids are stored outside the muscle cell are called extramyocellular lipids(EMCL), and lipids stored on the inside of muscle cells are called intramyocellular lipids(IMCL). The relationship between metabolic syndrome and IMCL has been extensively studied.AIM To determine the effects of muscle fiber orientations on muscle metabolites using ~1H MRS.METHODS Chicken muscles were used as the subject in this study. MRS spectra were performed on a 1.5 T Magnetic resonance imaging machine(1.5 Tesla Philips Achieva). A single voxel(8 mm × 8 mm × 20 mm) was placed on the chicken extensor iliotibialis lateralis muscle with the muscle fiber oriented at 0°, 30°, 60°,and 90° to the main magnetic field. ~1H MRS spectra were acquired using a pointresolved spectroscopy, TR = 2000 ms, TE = 30 ms, and NSA = 256. Metabolites of interest from each orientation to the main magnetic field were compared using Wilcoxon signed-rank test. Differences less than 0.05 were considered to be statistically significant with 95%CI.RESULTS The metabolite profiles were different for each orientation of muscle fibers to the main magnetic field. The orientation at 90° was the most different compared to other orientations. The quantity of IMCL and EMCL exhibited statistically significantly changes with impacts at 30°, 60°, and 90° when compared with muscles aligned at 0° to the main magnetic field. Statistical analysis showed statistically significant IMCL(CH_3), EMCL(CH_3), and IMCL(CH_2) at 30°, 60°, and 90°(P = 0.017, 0.018, and 0.018, respectively) and EMCL(CH_2) at 30° and 60°(P =0.017 and 0.042, respectively). EMCL(CH_2) at 90° was unable to be measured in this study. The muscle lipids quantified at 30°, 60°, and 90° tended to be lower when compared to 0°.CONCLUSION Careful positioning is one of the most important factors to consider when studying ~1H MRS metabolites in muscles to ensure reproducibility and uniformity of muscle metabolite spectra.

Theatre Arts as Social Marketing Application Tool： Sustainable Development Approach to Diffuse the Environmental Message to Teenagers in Chiang Mai, Thailand

Often, the word ＂community＂ and ＂sustainability＂ are interlinked in 21st century development approaches. Most development communicators have focused on top-down communication strategies and used various means to diffuse the message to the target community. However, with the change in media landscape today, the challenge is how to select the ＂right＂ communication application to foster the behavioral and cognitive sustainable changes in their own community. This research aims to investigate theatrical performance as sustainable communicative means demonstrating environmental issues and the concepts of sustainable development among high school students and Chiang Mai University students. With the application of ＂Devised Theatre＂, the process provides a space to investigate the attributes, characteristics and development of community theatre on how it reflects the concept of communication for social change. The research, therefore, examines the outcome of this creative social application tool and utilizes Practice as Research （PAR） a research methodology. The result will reveal the following： （1） how dramatic arts can be an effective means of social marketing to raise ＂awareness＂ on environmental issues; （2） how the performance raises environmental awareness in not only physical and psychological phases, but also spiritual dimension as a learning process among the participants, and （3） the sustainability of theatrical social application tool in which the participants of devised theatre project （devisees） can become the devisors in order to form new generation of the devisees--the teenage audience.

Risk Factors of Malnutrition among Karen Children in Chiang Mai, Thailand

The objective of this study was to determine the risk factors of malnutrition and its association with iron deficiency anaemia (IDA) among Karen hill tribe children. We conducted a study on blood samples from children from Baan Yang Poa School, Chiang Mai, Thailand aged between 9 and 15 years old. Of 193 children, 31 (16.1%) had malnutrition and 12 (6.2%) had IDA. Children who had at least five family members were found to have a significantly higher risk of malnutrition (P = 0.005), a reflection of the importance of socioeconomic factors in the problem of malnutrition. We also found that malnutrition was not associated with IDA although the assessment of the association of malnutrition and other types of anaemia is still of interest.

Integrated Behavioral Healthcare in Thailand:A Case Study from Chiang Mai

Purpose:This study aims to examine the level of behavioral health integration in primary care clinics among patients with hypertension and type 2 diabetes in Chiang Mai,Thailand.It also aims to explore the provider perceived prevalence of behavioral problems and need for an expert behavioral health consultant on the primary care team and the risk and protective factors of the patients’psychological and cardio-metabolic health outcomes.Methodology:Using survey data between 2017 and 2018 regarding the level of integration as measured by a Practice Integration Profile,provider ratings of prevalence and need based on a Provider Survey,and patient lifestyle and behavioral problems with a Health Risk Assessment in six primary health care settings in Chiang Mai,Thailand(n=335).We conducted ordinary least squares regressions to explore the relationship between each of the patient psychological and cardio-metabolic health outcomes and physical,mental health and substance abuse variables while controlling for the demographics.Results:The results showed overall high levels of integration,but significant variability across clinics.Providers rated prevalence of health risk and need for a Behavioral Health Consultant as moderate.Results of the patient health risk assessment were variable,with some problems high severity,others low.Conclusion:The results reflect a need for integrated behavioral health into the health care system in Thailand especially for those who are in the chronic illness condition.Recommendations for future study include an evaluation of the translation quality and validity and reliability of the study measures under the Thai context.This study fills the research gap of lacking research on the level of integrated care in clinics in Thailand.

Antioxidant Activities and Characterization of Polyphenols from Selected Northern Thai Rice Husks: Relation with Seed Attributes

Rice production generates a significant amount of agricultural waste. This study aimed to give results related to the existence of antioxidant phenols in agricultural waste of selected Northern Thai rice varieties. The antioxidant activities, contents of total flavonoids and phenolic compounds in the ethanolic rice husk extract were evaluated. The highest antioxidant activities were found in the variety PES1CMU, with 2,2’-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid and 2,2-diphenyl-1-picrylhydrazyl as 679.66 and 4.16 mmol/(L·g) trolox equivalent, respectively, ferric reducing antioxidant power as 0.87 mmol/(L·g) Fe2+, total phenolic content as 29.90 mmol/(L·g) gallic acid and total flavonoid content as 12.16 mg/g catechin equivalent. Polyphenol compounds were identified mainly by standard polyphenols using the liquid chromatography mass spectrometry, with the highest contents of phytic acid, o-coumaric acid, naringin and kaempferol. The non-glutenous and wetland ecotypes of rice husk samples were the richest in antioxidant activities and polyphenol contents characterized by using principal component analysis. The glutenous rice husk contained higher antioxidant activities than the rest. Interestingly, quercetin is a significant phenolic compound that positively correlated with the overall antioxidant activities of rice husk. This finding will be relevant for future application of rice husk antioxidant components in the production of functional ingredients as well as for the food and pharmaceutical industries.