Suranaree University of Technology

Abstract Application of nanomaterials for agriculture is relatively new as compared to their use in biomedical and industrial sectors. In order to promote sustainable nanoagriculture, biocompatible silver nanoparticles (AgNPs) have been synthesized through green route using kaffir lime leaf extract for use as nanopriming agent for enhancing seed germination of rice aged seeds. Results of various characterization techniques showed the successful formation of AgNPs which were capped with phytochemicals present in the plant extract. Rice aged seeds primed with phytosynthesized AgNPs at 5 and 10 ppm significantly improved germination performance and seedling vigor compared to unprimed control, AgNO 3 priming, and conventional hydropriming. Nanopriming could enhance α-amylase activity, resulting in higher soluble sugar content for supporting seedlings growth. Furthermore, nanopriming stimulated the up-regulation of aquaporin genes in germinating seeds. Meanwhile, more ROS production was observed in germinating seeds of nanopriming treatment compared to unprimed control and other priming treatments, suggesting that both ROS and aquaporins play important roles in enhancing seed germination. Different mechanisms underlying nanopriming-induced seed germination were proposed, including creation of nanopores for enhanced water uptake, rebooting ROS/antioxidant systems in seeds, generation of hydroxyl radicals for cell wall loosening, and nanocatalyst for fastening starch hydrolysis.

BACKGROUND: This paper is a summary of the proceedings of the International Association of Paediatric Dentistry Bangkok Conference on early childhood caries (ECC) held in 3-4 November 2018. AIM: The paper aims to convey a global perspective of ECC definitions, aetiology, risk factors, societal costs, management, educational curriculum, and policy. DESIGN: This global perspective on ECC is the compilation of the state of science, current concepts, and literature regarding ECC from worldwide experts on ECC. RESULTS: Early childhood caries is related to frequent sugar consumption in an environment of enamel adherent, acid-producing bacteria in a complex biofilm, as well as developmental defects of enamel. The seriousness, societal costs, and impact on quality of life of dental caries in pre-school children are enormous. Worldwide data show that ECC continues to be highly prevalent, yet infrequently treated. Approaches to reduce the prevalence include interventions that start in the first year of a child's life, evidence-based and risk-based management, and reimbursement systems that foster preventive care. CONCLUSIONS: This global perspective on ECC epidemiology, aetiology, risk assessment, global impact, and management is aimed to foster improved worldwide understanding and management of ECC.

Abstract At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark–gluon plasma (QGP) 1 . Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed 2,3,4,5,6 . Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions 7 , is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton–proton (pp) collisions 8,9 , but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton–proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p–Pb collision results 10,11 , indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb–Pb collisions, where a QGP is formed.

Quantum computing hardware technologies have advanced during the past two decades, with the goal of building systems that can solve problems that are intractable on classical computers. The ability to realize large-scale systems depends on major advances in materials science, materials engineering, and new fabrication techniques. We identify key materials challenges that currently limit progress in five quantum computing hardware platforms, propose how to tackle these problems, and discuss some new areas for exploration. Addressing these materials challenges will require scientists and engineers to work together to create new, interdisciplinary approaches beyond the current boundaries of the quantum computing field.

Based on first-principles calculations, a model for large-size-mismatched group-V dopants in ZnO is proposed. The dopants do not occupy the O sites as is widely perceived, but rather the Zn sites: each forms a complex with two spontaneously induced Zn vacancies in a process that involves fivefold As coordination. Moreover, an As(Zn)-2V(Zn) complex may have lower formation energy than any of the parent defects. Our model agrees with the recent observations that both As and Sb have low acceptor-ionization energies and that to obtain p-type ZnO requires O-rich growth or annealing conditions.

Denaturing gradient gel electrophoresis (DGGE) of DNA fragments obtained by PCR amplification of the V2-V3 region of the 16S rRNA gene was used to detect the presence of Lactobacillus species in the stomach contents of mice. Lactobacillus isolates cultured from human and porcine gastrointestinal samples were identified to the species level by using a combination of DGGE and species-specific PCR primers that targeted 16S-23S rRNA intergenic spacer region or 16S rRNA gene sequences. The identifications obtained by this approach were confirmed by sequencing the V2-V3 region of the 16S rRNA gene and by a BLAST search of the GenBank database.

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTElectrochemical Biosensor Applications of Polysaccharides Chitin and ChitosanWipa Suginta, Panida Khunkaewla, and Albert Schulte*View Author Information Biochemistry and Electrochemistry Research Unit, Schools of Chemistry and Biochemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand*Phone: +66-44-22-6187. Fax: +66-44-22-4185. E-mail: [email protected]Cite this: Chem. Rev. 2013, 113, 7, 5458–5479Publication Date (Web):April 4, 2013Publication History Received9 August 2012Published online4 April 2013Published inissue 10 July 2013https://pubs.acs.org/doi/10.1021/cr300325rhttps://doi.org/10.1021/cr300325rreview-articleACS PublicationsCopyright © 2013 American Chemical SocietyRequest reuse permissionsArticle Views13435Altmetric-Citations425LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Biopolymers,Biotechnology,Electrodes,Peptides and proteins,Sensors Get e-Alerts

Recent theory has found that native defects such as the O vacancy V(O) and Zn interstitial Zn(I) have high formation energies in n-type ZnO and, thus, are not important donors, especially in comparison to impurities such as H. In contrast, we use both theory and experiment to show that, under N ambient, the complex Zn(I)-N(O) is a stronger candidate than H or any other known impurity for a 30 meV donor commonly found in bulk ZnO grown from the vapor phase. Since the Zn vacancy is also the dominant acceptor in such material, we must conclude that native defects are important donors and acceptors in ZnO.

Problematic soils with high compressibility and low shear strength are often treated with traditional chemical stabilizing additives such as cement and lime to improve their engineering properties. These additives are generally recognized as having less than ideal environmental impacts—in particular, the high quantity of greenhouse gases that are generally created during their production. With an increasing focus on the use of more environmentally friendly and sustainable materials in the built and natural environments, alternative eco-friendly additives to traditional chemical stabilizers have the potential to significantly change the field of soil improvement worldwide. The current study illustrates the viability of xanthan gum as an environmentally friendly stabilizer that can improve the engineering properties of both low- and high-swelling clays. Experimental mechanical tests were performed on both untreated and xanthan gum–stabilized montmorillonite and kaolinite clays at various curing times, including unconfined compression strength (UCS) tests, direct shear tests, and one-dimensional (1D) consolidation tests. Various microscopic techniques were also performed to characterize the microstructure of the stabilized soil matrix, including field emission scanning electron microscopy (FESEM) tests, Brunauer, Emmett, and Teller (N2-BET) surface area analysis tests, and particle size analysis (PSA) tests using a laser diffraction approach. From the results of the strength and compressibility testing, 1 and 1.5% xanthan gum contents were found to be optimum levels of additive use for the montmorillonite and kaolinite clays, respectively. The microstructural analysis tests performed indicated the formation of new cementitious products that result from chemical reactions between the xanthan gum and soil particles at the microlevel, which improved the soil structure by welding soil particles together and filling the pore space in the soil matrix. Significant engineering property improvement was observed during the first 28 days of curing; this improvement corresponded to significant changes in the soil’s microstructure that occurred over the same period of time.

Two centuries after the discovery of chitin, it is widely accepted that this biopolymer is an important biomaterial in many aspects. Numerous studies on chitin have focused on its biomedical applications. In this review, various aspects of chitin research including sources, structure, biosynthesis, chitinolytic enzyme, chitin binding protein, genetic engineering approach to produce chitin, chitin and evolution, and a wide range of applications in bio- and nanotechnology will be dealt with.

Native point defects in anatase $\mathrm{Ti}{\mathrm{O}}_{2}$ are investigated by using first-principles pseudopotential calculations based on density-functional theory (DFT). Antisite defects, namely, Ti-antisite $({\mathrm{Ti}}_{\mathrm{O}})$ and O-antisite $({\mathrm{O}}_{\mathrm{Ti}})$, have high formation energies and are hence unstable. In contrast, all other fundamental native defects (${\mathrm{Ti}}_{i}$, ${\mathrm{O}}_{i}$, ${V}_{\mathrm{Ti}}$, and ${V}_{\mathrm{O}}$) have low formation energies. In particular, titanium interstitial $({\mathrm{Ti}}_{i})$ is a quadruple donor defect with lowest formation energy in $p$-type samples, whereas Ti vacancy $({V}_{\mathrm{Ti}})$ is a quadruple acceptor defect with lowest formation energy in $n$-type samples. Interstitial oxygen $({\mathrm{O}}_{i})$ would spontaneously and strongly bind to lattice oxygen, resulting in a neutral ${\mathrm{O}}_{2}$ dimer substituting on one O site. None of the four low-energy defects have energy levels inside the DFT band gap.

Three-dimensional (3D) culture systems are becoming increasingly popular due to their ability to mimic tissue-like structures more effectively than the monolayer cultures. In cancer and stem cell research, the natural cell characteristics and architectures are closely mimicked by the 3D cell models. Thus, the 3D cell cultures are promising and suitable systems for various proposes, ranging from disease modeling to drug target identification as well as potential therapeutic substances that may transform our lives. This review provides a comprehensive compendium of recent advancements in culturing cells, in particular cancer and stem cells, using 3D culture techniques. The major approaches highlighted here include cell spheroids, hydrogel embedding, bioreactors, scaffolds, and bioprinting. In addition, the progress of employing 3D cell culture systems as a platform for cancer and stem cell research was addressed, and the prominent studies of 3D cell culture systems were discussed.

Nanoparticles are defined as ultrafine particles sized between 1 and 100 nanometres in diameter. In recent decades, there has been wide scientific research on the various uses of nanoparticles in construction, electronics, manufacturing, cosmetics, and medicine. The advantages of using nanoparticles in construction are immense, promising extraordinary physical and chemical properties for modified construction materials. Among the many different types of nanoparticles, titanium dioxide, carbon nanotubes, silica, copper, clay, and aluminium oxide are the most widely used nanoparticles in the construction sector. The promise of nanoparticles as observed in construction is reflected in other adoptive industries, driving the growth in demand and production quantity at an exorbitant rate. The objective of this study was to analyse the use of nanoparticles within the construction industry to exemplify the benefits of nanoparticle applications and to address the short-term and long-term effects of nanoparticles on the environment and human health within the microcosm of industry so that the findings may be generalised. The benefits of nanoparticle utilisation are demonstrated through specific applications in common materials, particularly in normal concrete, asphalt concrete, bricks, timber, and steel. In addition, the paper addresses the potential benefits and safety barriers for using nanomaterials, with consideration given to key areas of knowledge associated with exposure to nanoparticles that may have implications for health and environmental safety. The field of nanotechnology is considered rather young compared to established industries, thus limiting the time for research and risk analysis. Nevertheless, it is pertinent that research and regulation precede the widespread adoption of potentially harmful particles to mitigate undue risk.

Three techniques are used to probe the pseudogap state of cuprate high-temperature superconductors.

Angular correlations between unidentified charged trigger particles and various species of charged associated particles (unidentified particles, pions, kaons, protons and antiprotons) are measured by the ALICE detector in p–Pb collisions at a nucleon–nucleon centre-of-mass energy of 5.02 TeV in the transverse-momentum range 0.3<pT<4 GeV/c. The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range |ηlab|<0.8. Fourier coefficients are extracted from the long-range correlations projected onto the azimuthal angle difference and studied as a function of pT and in intervals of event multiplicity. In high-multiplicity events, the second-order coefficient for protons, v2p, is observed to be smaller than that for pions, v2π, up to about pT=2 GeV/c. To reduce correlations due to jets, the per-trigger yield measured in low-multiplicity events is subtracted from that in high-multiplicity events. A two-ridge structure is obtained for all particle species. The Fourier decomposition of this structure shows that the second-order coefficients for pions and kaons are similar. The v2p is found to be smaller at low pT and larger at higher pT than v2π, with a crossing occurring at about 2 GeV/c. This is qualitatively similar to the elliptic-flow pattern observed in heavy-ion collisions. A mass ordering effect at low transverse momenta is consistent with expectations from hydrodynamic model calculations assuming a collectively expanding system.

Calcium carbide residue (CCR) and fly ash (FA) are both waste products from acetylene gas factories and power plants, respectively. The mixture of CCR and FA produces a cementitious material because CCR contains a lot of Ca(OH)2, while FA is a pozzolanic material. This paper investigates the possibility of using this cementitious material (a mixture of CCR and FA) to improve the strength of problematic silty clay in northeast Thailand. The influential factors involved in this study are water content, binder content, CCR∶FA ratio, and curing time. The mechanism controlling the development of strength is also illustrated. Strength development is investigated using the unconfined compression test. A microstructural study using a scanning electron microscope and thermal gravity analysis is performed to understand the microstructural changes that accompany the influential factors. Both strength and microstructural investigations reveal that the input of CCR reduces specific gravity and soil plasticity; thus, the maximum dry unit weight and water sensitivity. The maximum strength of the stabilized silty clay occurs at approximately the optimum water content for different binder contents, CCR∶FA ratios, and curing times. The improvement in strength for a particular curing time is classified into three zones: active, inert, and deterioration. In the active zone, the strength increases remarkably with the CCR content for all CCR∶FA ratios. The input of FA (CCR replacement) does not significantly enhance strength development because all input Ca(OH)2 is consumed by the natural pozzolanic material in the soil in the pozzolanic reaction. This active zone can be determined from the CCR fixation point, which is simply obtained from the index test. The input of FA (CCR replacement) is effective when the CCR content is in excess of the active zone, where insufficient natural pozzolanic material in the soil is present to react with the Ca(OH)2. The possible mechanism controlling strength development that is presented in this paper can be applied to the other clayey soils stabilized with different cementitious materials, produced from Ca(OH)2-rich materials and pozzolanic materials, to explain and analyze strength development. Further study on a development of rational dosage methodology will be fundamental.

The ALICE measurement of ${K}_{S}^{0}$ and $\ensuremath{\Lambda}$ production at midrapidity in Pb-Pb collisions at $\sqrt{{s}_{NN}}=2.76\text{ }\text{ }\mathrm{TeV}$ is presented. The transverse momentum (${p}_{T}$) spectra are shown for several collision centrality intervals and in the ${p}_{T}$ range from $0.4\text{ }\text{ }\mathrm{GeV}/c$ ($0.6\text{ }\text{ }\mathrm{GeV}/c$ for $\ensuremath{\Lambda}$) to $12\text{ }\text{ }\mathrm{GeV}/c$. The ${p}_{T}$ dependence of the $\ensuremath{\Lambda}/{K}_{S}^{0}$ ratios exhibits maxima in the vicinity of $3\text{ }\text{ }\mathrm{GeV}/c$, and the positions of the maxima shift towards higher ${p}_{T}$ with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate ${p}_{T}$ is not observed in $pp$ interactions at $\sqrt{s}=0.9\text{ }\text{ }\mathrm{TeV}$ and at $\sqrt{s}=7\text{ }\text{ }\mathrm{TeV}$. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured ${p}_{T}$ spectra above $2\text{ }\text{ }\mathrm{GeV}/c$ progressively decouple from hydrodynamical-model calculations. For higher values of ${p}_{T}$, models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the ${p}_{T}$ dependence of the $\ensuremath{\Lambda}/{K}_{S}^{0}$ ratio.

The diffusion of relevant native point defects in wurtzite GaN crystals is investigated using first-principles density-functional pseudopotential calculations. Our reexamination of the ground state of the defects, using a higher level of convergence than was previously used, yields results in good agreement with earlier published results [J. Neugebauer and C. G. Van de Walle, Phys. Rev. B $50,$ 8067 (1994)]. Gallium interstitials are stable at the octahedral interstitial site and can occur in 1+, 2+ (metastable), or 3+ charge states. They migrate via an interstitialcy mechanism with an unexpectedly low barrier of 0.9 eV, consistent with the annealing of the $L5$ signal in electron-paramagnetic-resonance experiments [K. H. Chow et al., Phys. Rev. Lett. $85,$ 2761 (2000)]. For the nitrogen interstitial the ground-state configuration is a split interstitial, occurring in charge states ranging from $1\ensuremath{-}$ to 3+. Migration also proceeds via an interstitialcy mechanism, with barriers of 2.4 eV or lower, depending on the charge state. The nitrogen vacancy has two stable charge states 1+ and 3+. The migration barrier for ${V}_{\mathrm{N}}^{+}$ is high (4.3 eV), while the migration barrier for ${V}_{\mathrm{N}}^{3+}$ is significantly lower, at 2.6 eV, consistent with recent positron-annihilation experiments [S. Hautakangas et al., Phys. Rev. Lett. $90,$ 137402 (2003)]. The gallium vacancy, finally, can occur in charge states 0, $1\ensuremath{-},$ $2\ensuremath{-},$ and $3\ensuremath{-},$ and migrates with a barrier of 1.9 eV. For all these defects the lowest-energy migration path results in motion both parallel and perpendicular to the c axis; no anisotropy in the diffusion will therefore be observed. Applications to point-defect-assisted impurity diffusion will also be discussed.

Early Childhood Caries (ECC) is prevalent around the world, but in particular the disease is growing rapidly in low- and middle-income countries in parallel with changing diet and lifestyles. In many countries, ECC is often left untreated, a condition which leads to pain and adversely affects general health, growth and development, and quality of life of children, their families and their communities. Importantly, ECC is also a global public health burden, medically, socially and economically. In many countries, a substantial number of children require general anaesthesia for the treatment of caries in their primary teeth (usually extractions), and this has considerable cost and social implications. A WHO Global Consultation with oral health experts on "Public Health Intervention against Early Childhood Caries" was held on 26-28 January 2016 in Bangkok (Thailand) to identify public health solutions and to highlight their applicability to low- and middle-income countries. After a 3-day consultation, participants agreed on specific recommendations for further action. National health authorities should develop strategies and implement interventions aimed at preventing and controlling ECC. These should align with existing international initiatives such as the Sixtieth World Health Assembly Resolution WHA 60.17 Oral health: action plan for promotion and integrated disease prevention, WHO Guideline on Sugars and WHO breastfeeding recommendation. ECC prevention and control interventions should be integrated into existing primary healthcare systems. WHO public health principles must be considered when tackling the effect of social determinants in ECC. Initiatives aimed at modifying behaviour should focus on families and communities. The involvement of communities in health promotion, and population-directed and individual fluoride administration for the prevention and control of ECC is essential. Surveillance and research, including cost-effectiveness studies, should be conducted to evaluate interventions aimed at preventing ECC in different population groups.

A large amount of agro-industrial waste is produced worldwide in various agricultural sectors and by different food industries. The disposal and burning of this waste have created major global environmental problems. Agro-industrial waste mainly consists of cellulose, hemicellulose and lignin, all of which are collectively defined as lignocellulosic materials. This waste can serve as a suitable substrate in the solid-state fermentation process involving mushrooms. Mushrooms degrade lignocellulosic substrates through lignocellulosic enzyme production and utilize the degraded products to produce their fruiting bodies. Therefore, mushroom cultivation can be considered a prominent biotechnological process for the reduction and valorization of agro-industrial waste. Such waste is generated as a result of the eco-friendly conversion of low-value by-products into new resources that can be used to produce value-added products. Here, we have produced a brief review of the current findings through an overview of recently published literature. This overview has focused on the use of agro-industrial waste as a growth substrate for mushroom cultivation and lignocellulolytic enzyme production.