Search results for: imaging contrast agent

Authors: Takahiro Ishizaki, Shutaro Hisada, Oi Lun Li

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Control of surface wettability is very important in various industrial fields. Thus, contact angle hysteresis which is defined as the difference between advancing and receding water contact angles has been paid attention because the surface having low contact angle hysteresis can control wetting behavior of water droplet. Self-assembled monolayer (SAM) formed using organic silane molecules has been used to control surface wettability, in particular, static contact angles, however, the effect of alkyl-chain length in organic silane molecules on the contact angle hysteresis has not yet clarified. In this study, we aimed to investigate the effect of alkyl-chain length (C1-C18) in organic silane molecules on the contact angle hysteresis. SAMs were formed on Si wafer by thermal CVD method using silane coupling agents having different alkyl-chain length. The static water contact angles increased with an increase in the alkyl-chain length. On the other hand, although the water contact angle hysteresis tended to decrease with an increase in the alkyl-chain length, in case of the alkyl-chain length of more than C16 the contact angle hysteresis increased. This could be due to the decrease in the molecular mobility because of the increase in the molecular packing density in chemisorbed silane molecules.

Keywords: alkyl-chain length, self-assembled monolayer, silane coupling agent, surface wettability

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Authors: Venus Pagare, Amit Kharat, Dhaval K. Thakkar, Tushar J. Palekar

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Introduction: Chronic low back pain (CLBP) is a major public health problem and is the leading musculoskeletal cause of disability. Altered neuromuscular control of core muscles, particulary transverses abdominis (TrA) is thought to be a contributing factor for the development of CLBP. Therefore, various exercises targeting the TrA are commonly incorporated into the rehabilitation. Objectives: To investigate the effects of 3 different core exercises on activation capacity of TrA muscle in individuals with CLBP as compared with healthy controls. Methodology: Thickness of TrA muscle was measured by ultrasound imaging in 30 patients with CLBP and 30 healthy controls. Measurements were taken during 3 different TrA activation exercises i.e Abdominal drawing in maneuver (ADIM), Abdominal drawing in with straight leg raise (ADSLR) and breathe hold at maximum expiration (ME). Thickness of the muscle at rest (at the end of normal tidal expiration) was taken as a baseline measure. Results: There was a significant difference between the healthy subjects and patients with low back pain with regard to the thickness of TrA at rest and thickness during contraction. ADIM produced a significant increase in the thickness of TrA compared to ADSLR and ME (p<0.001). Also, increase in thickness of TrA was more in the control group than patients with low back pain. Conclusion: CLBP patients exhibited atrophy of TrA muscle with delayed activation. Also, of the various core exercises, ADIM can be an effective method for activation of TrA.

Keywords: LBP, CLBP, ADSLR, ADIM

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Authors: Mahdieh Jajroudi

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Developing a pharmacokinetic model for the neuroendocrine tumors therapy agent 177Lu-DOTATATE in nude mice bearing AR42J rat pancreatic tumor to investigate and evaluate the behavior of the complex was the main purpose of this study. The utilization of compartmental analysis permits the mathematical differencing of tissues and organs to become acquainted with the concentration of activity in each fraction of interest. Biodistribution studies are onerous and troublesome to perform in humans, but such data can be obtained facilely in rodents. A physiologically based pharmacokinetic model for scaling up activity concentration in particular organs versus time was developed. The mathematical model exerts physiological parameters including organ volumes, blood flow rates, and vascular permabilities; the compartments (organs) are connected anatomically. This allows the use of scale-up techniques to forecast new complex distribution in humans' each organ. The concentration of the radiopharmaceutical in various organs was measured at different times. The temporal behavior of biodistribution of 177Lu labeled somatostatin analogues was modeled and drawn as function of time. Conclusion: The variation of pharmaceutical concentration in all organs is characterized with summation of six to nine exponential terms and it approximates our experimental data with precision better than 1%.

Keywords: biodistribution modeling, compartmental analysis, 177Lu labeled somatostatin analogues, neuroendocrine tumors

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Authors: Nino Kupatadze, Tamar Memanishvili, Natia Ochkhikidze, David Tugushi, Zaal Kokaia, Ramaz Katsarava

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Amino acid-based Biodegradable poly(ester-amide)s (PEAs) have gained considerable interest as a promising materials for numerous biomedical applications. These polymers reveal a high biocompatibility and easily form small particles suitable for delivery various biological, as well as elastic bio-erodible films serving as matrices for constructing antibacterial coatings. In the present work we have demonstrated a potential of the PEAs for two applications: 1. cell therapy for stroke as vehicles for delivery and sustained release of growth factors, 2. bactericidal coating as prevention biofilm and applicable in infected wound management. Stroke remains the main cause of adult disability with limited treatment options. Although stem cell therapy is a promising strategy, it still requires improvement of cell survival, differentiation and tissue modulation. .Recently, microspheres (MPs) made of biodegradable polymers have gained significant attention for providing necessary support of transplanted cells. To investigate this strategy in the cell therapy of stroke, MPs loaded with transcription factors Wnt3A/BMP4 were prepared. These proteins have been shown to mediate the maturation of the cortical neurons. We have suggested that implantation of these materials could create a suitable microenvironment for implanted cells. Particles with spherical shape, porous surface, and 5-40 m in size (monitored by scanning electron microscopy) were made on the basis of the original PEA composed of adipic acid, L-phenylalanine and 1,4-butanediol. After 4 months transplantation of MPs in rodent brain, no inflammation was observed. Additionally, factors were successfully released from MPs and affected neuronal cell differentiation in in vitro. The in vivo study using loaded MPs is in progress. Another severe problem in biomedicine is prevention of surgical devices from biofilm formation. Antimicrobial polymeric coatings are most effective “shields” to protect surfaces/devices from biofilm formation. Among matrices for constructing the coatings preference should be given to bio-erodible polymers. Such types of coatings will play a role of “unstable seating” that will not allow bacteria to occupy the surface. In other words, bio-erodible coatings would be discomfort shelter for bacteria that along with releasing “killers of bacteria” should prevent the formation of biofilm. For this purpose, we selected an original biodegradable PEA composed of L-leucine, 1,6-hexanediol and sebacic acid as a bio-erodible matrix, and nanosilver (AgNPs) as a bactericidal agent (“killer of bacteria”). Such nanocomposite material is also promising in treatment of superficial wound and ulcer. The solubility of the PEA in ethanol allows to reduce AgNO3 to NPs directly in the solution, where the solvent served as a reductive agent, and the PEA served as NPs stabilizer. The photochemical reduction was selected as a basic method to form NPs. The obtained AgNPs were characterized by UV-spectroscopy, transmission electron microscope (TEM), and dynamic light scattering (DLS). According to the UV-data and TEM data the photochemical reduction resulted in spherical AgNPs with wide particle size distribution with a high contribution of the particles below 10 nm that are known as responsible for bactericidal activity of AgNPs. DLS study showed that average size of nanoparticles formed after photo-reduction in ethanol solution ranged within ca. 50 nm.

Keywords: biodegradable polymers, microparticles, nanocomposites, stem cell therapy, stroke

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Authors: Marwa Al-Subhi, Eiman Al-Ajmi, Mallak Al-Maamari, Humood Al-Dhuhli, Srinivasa Rao

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The orbit and its contents are affected by various pathologies and craniofacial anomalies. Sound knowledge of the normal orbital dimensions is clinically essential for successful surgical outcomes and also in the field of forensic anthropology. Racial, ethnic, and regional variations in the orbital dimensions have been reported. This study sought to determine the orbital dimensions of Omani subjects who had been referred for computed tomography (CT) images at a tertiary care hospital. A total of 273 patients’ CT images were evaluated retrospectively by using an electronic medical records database. The orbital dimensions were recorded using both axial and sagittal planes of CT images. The mean orbital index (OI) was found to be 83.25±4.83 and the prevalent orbital type was categorized as mesoseme. The mean orbital index was 83.34±5.05 and 83.16±4.57 in males and females, respectively, with their difference being statistically not significant (p=0.76). A statistically significant association was observed between the right and left orbits with regard to horizontal distance (p<0.05) and vertical distance (p<0.01) of orbit and OI (p<0.05). No significant difference between the OI and age groups was observed in both males and females. The mean interorbital distance and interzygomatic distance were found to be 19.45±1.52 mm and 95.59±4.08 mm, respectively. Both of these parameters were significantly higher in males (p<0.05). Results of the present study provide reference values of orbital dimensions in Omani subjects. The prevalent orbital type of Omani subjects is mesoseme, which is a hallmark of the white race.

Keywords: orbit, orbital index, mesoseme, ethnicity, variation

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Authors: Tzuli Lin

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This paper aims to explore that the EU and Member State (UK) converges on cultural diplomacy to constitute an influential European external relations. It will address the development of EU cultural diplomacy and practice at Member state level. It also discusses the EU and Member States suffering in cultural resource overlapped. In contrast to the literature on the EU external relations, studies of the cultural dimension are rare. Thus, this paper will utilise the broad policy papers to explore how the cultural diversity among the Member States and the EU has a constructive progress at European level but not at Member State level. It can be argued that cultural component is the pivotal strategy for the stagnated EU external relations since the Euro crisis. The EU recognises that if it wants to promote the trade relations from the inside of Europe to outside, it requires the broad culture context among its traditional diplomacy, which brings the cultural component into a significant role. Even though in the area of Member State level, they share the fundamental value and idea, it does not elaborate Member States regarding the EU as a representative of European cultural diplomacy. In theory and practice, the discourse of Normative Power Europe (NPE) can be the analytic framework to construct the research of cultural diplomacy in Europe. NPE is an idea of the EU’s global role and spreading its norms to others. Moreover, Member States’ national interest has supreme priority rather than the EU. Therefore, this paper will utilise the UK as a case study to explore that cultural diplomacy shows fragmentation at European level. In the result, this paper will illustrate that the EU and the UK have mutual recognised each other as a partner not a leader.

Keywords: EU cultural diplomacy, cultural policy, cultural diversity, normative power

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Authors: Khairul Bariah Sulaiman, Tajul Aris Yang

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Fermentation is well known as an essential process in cocoa beans. Besides to develop the precursor of cocoa flavour, it also induce the colour changes in the beans.The fermentation process is reported to be influenced by duration of pod storage and fermentation. Therefore, this study was conducted to evaluate colour of Malaysian cocoa beans and how the pods storage and fermentation duration using shallow box technique will effect on it characteristics. There are two factors being studied ie duration of cocoa pod storage (0, 2, 4, and 6 days) and duration of cocoa fermentation (0, 1, 2, 3, 4 and 5 days). The experiment is arranged in 4 x 6 factorial design with 24 treatments and arrangement is in a Completely Randomised Design (CRD). The produced beans is inspected for colour changes under artificial light during cut test and divided into four groups of colour namely fully brown, purple brown, fully purple and slaty. Cut tests indicated that cocoa beans which are directly dried without undergone fermentation has the highest slaty percentage. However, application of pods storage before fermentation process is found to decrease the slaty percentage. In contrast, the percentages of fully brown beans start to dominate after two days of fermentation, especially from four and six days of pods storage batch. Whereas, almost all batch have percentage of fully purple less than 20%. Interestingly, the percentage of purple brown beans are scattered in the entire beans batch regardless any specific trend. Meanwhile, statistical analysis using General Linear Model showed that the pods storage has a significant effect on the colour characteristic of the Malaysian dried beans compared to fermentation duration.

Keywords: cocoa beans, colour, fermentation, shallow box

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Authors: Afolabi Joseph Fasoranti

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Tuberculosis (TB) is an infectious disease caused by mycobacterium tuberculosis. Tuberculosis is a major public health problem in Nigeria, being one of the ten leading causes of hospital admissions and a leading cause of death in adults, especially among the economically productive age group. This paper critically examined the importance of health education towards the eradication and prevention of tuberculosis in Nigeria. It was reviewed and discussed under the following subheadings; Global burden of tuberculosis in Nigeria, concept, definition and etiology of tuberculosis, Signs and symptoms of tuberculosis, diagnosis of tuberculosis, causative agent, modes of infection and incubation period, risk factors of pulmonary tuberculosis Dots and stop TB programmes in Nigeria Treatment and prevention of tuberculosis TB treatment strategies, Dealing with treatment problems in Nigeria Stigmatization against Tuberculosis Patients Health education as a tool for achieving free tuberculosis country. Emphasis for Tb control has been placed on the development of improved vaccines, diagnostic and treatment courses but less on health education and awareness. Although the need for these tools is indisputable, the obstacle facing the spread of TB go beyond technological. The findings of this study may stimulate health system policy makers, Government and non- governmental organizations, donor agencies and other stakeholders in planning and designing health education intervention programs on the control and eradication of tuberculosis. It therefore recommended that Government should implement health education as part of the DOTs, this will thus empower the tuberculosis patients on ways to live healthy, lifestyle, in doing this, they will recover fast and prevent them from spreading the disease.

Keywords: tuberculosis, health education, panacea, Nigeria, prevention

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Authors: Jonathan Andres Pullas Navarrete, Ernesto Hale de la Torre Chauvin

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In this work, the antibacterial effect of activated carbon fibers (ACF) impregnated with ionic silver particles was studied. ACF were prepared from samples of cotton woven wastes (cotton based fabrics 5x10 cm) by applying a chemical activation procedure with H3PO4. This treatment was performed using several H3PO4: Cotton based fabrics weight ratios (1:2–2:1), temperatures (600–900 ºC) and activation times (0.5–2 h). The ACF obtained under the best activation conditions showed BET surface area of 1103 m2/g; this result along with iodine index demonstrated the microporous nature of the fibers herein obtained. Then, the obtained fibers were impregnated with ionic silver particles by immersion in 0.1 and 0.5 M AgNO3 solutions followed by drying and thermal decomposition in order to fix the silver particles in the structure of ACF. It was determined that the presence of Ag ions lowered the BET surface area of the ACF in approximately 17 % due to the obstruction of the porosities along the carbonized structure. Finally, the antibacterial effect of the ACF impregnated with silver was studied through direct counting method for coliforms. The antibacterial activity of the impregnated fibers was demonstrated, and it was attributed to the strongly inhibition of bacteria growth because of chemical properties of the particles of silver inside the ACF. This behavior was demonstrated at concentrations of silver as low as 0.035 % w/w.

Keywords: activated carbon, adsorption, antibacterial activity, coliforms, surface area

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Authors: Akram Boubakri, Fethi Choubeni, Tan Hoa Vuong, Jacques David

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The control of electromagnetic waves is a key aim of several researches over the past decade. In this regard, Metamaterials have shown a strong ability to manipulate the electromagnetic waves on a subwavelength scales thanks to its unconventional properties that are not available in natural materials such as negative refraction index, super imaging and invisibility cloaking. Metalenses were used to avoid some drawbacks presented by conventional lenses since focusing with conventional lenses suffered from the limited resolution because they were only able to focus the propagating wave component. Nevertheless, Metalenses were able to go beyond the diffraction limit and enhance the resolution not only by collecting the propagating waves but also by restoring the amplitude of evanescent waves that decay rapidly when going far from the source and that contains the finest details of the image. Metasurfaces have many mechanical advantages over three-dimensional metamaterial structures especially the ease of fabrication and a smaller required volume. Those structures have been widely used for antenna performance improvement and to build flat metalenses. In this work, we showed that a well-designed metasurface lens operating at the frequency of 5.9GHz, has efficiently enhanced the radiation characteristics of a patch antenna and can be used for WLAN applications (IEEE 802.11 a). The proposed metasurface lens is built with a geometrically modified unit cells which lead to a change in the response of the lens at different position and allow the control of the wavefront beam of the incident wave thanks to the gradient refractive index.

Keywords: focusing, gradient index, metasurface, metalens, WLAN Applications

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Authors: Hanjun Zhao, Ke Zhang, Bojian Zheng

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Background: So far, there is no universal antiviral agent which can inhibit multiple viral infections. More and more drug-resistant viral strains emerge after the antiviral drug application for treatment. Defensins are the front line of host innate immunity and have broad spectrum antibacterial and antiviral effects. However, there is limited data to show if these defensins have good antiviral activity in vivo and what the antiviral mechanism is. Subjects: To investigate a peptide with widespread antivirus activity in vitro and in vivo and illustrate the antiviral mechanism. Methods: Antiviral peptide library designed from mouse beta defensins was synthesized by the company. Recombinant beta defensin was obtained from E. coli. Antiviral activity in vitro was assayed by plaque assay, qPCR. Antiviral activity in vivo was detected by animal challenge with 2009 pandemic H1N1 influenza A virus. The antiviral mechanism was assayed by western blot, ELISA, and qPCR. Conclusions: We identify a new peptide which has widespread effects against multiple viruses (H1N1, H5N1, H7N9, MERS-CoV) in vitro and has efficient antivirus activity in vivo. This peptide inhibits viral entry into target cells and subsequently blocks viral replication. The in vivo study of the antiviral peptide against other viral infections and the investigation of its more detail antiviral mechanism are ongoing.

Keywords: antiviral peptide, defensin, Influenza A virus, mechanism

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Authors: Ahmed Al-Mansour, Qiang Zeng

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Recycling waste plastics in the form of concrete components, i.e. fine aggregates, has been an attractive topic among the society of civil engineers. Not only does the recycling of plastics reduce the overall cost of concrete production, but it also takes part in solving environmental issues. Nevertheless, the incorporation of recycled plastics into concrete results in an increasing reduction in the mechanical properties of concrete as the percentage of replacement of natural aggregates increases. In order to overcome this reduction, Ethylene-vinyl acetate (EVA) was used as an additive in concrete with recycled plastic aggregates. The aim of this additive is to: 1) increase the interfacial interaction at the interfacial transition zone (ITZ) between plastic pellets and cement matrix, and 2) mitigate the loss in mechanical properties. Three different groups of samples (i.e. cubes and prisms) were tested according to the plastics substituting fine aggregates. 5, 10, and 15% of fine aggregates were substituted for recycled plastic pellets, and 2 – 4% of the cement was substituted for EVA that produces a flexible agent when mixed properly with water. Compressive and tensile strength tests were conducted for the mechanical properties, while SEM and X-CT scan were implemented for further investigation of calcium-silicate-hydrate (C–S–H) formation and ITZ analysis. The optimal amount of plastic particles with EVA is suggested to get the most compact and dense matrix structure according to the results of this study.

Keywords: the durability of concrete, ethylene-vinyl acetate (EVA), interfacial transition zone (ITZ), recycled plastics

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Authors: Erdem Elibol, Musa Cadırcı, Nedim Tutkun

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Recently, colloidal quantum dots (CQDs) have drawn increasing attention due to their unique size tunability, which makes them potential candidates for numerous applications including photovoltaic, LEDs, and imaging. However, the main challenge to exploit CQDs properly is that there has not been an effective method to produce them with highly crystalline form and narrow size dispersion. Hot injection method is one of the widely used techniques to produce high-quality nanoparticles. In this method, the key parameter is to reduce the time for injection of the precursors into each other, which yields fast and constant nucleation rate and hence to highly monodisperse QDs. In conventional hot injection method, the injection of precursors is carried out using standard lab syringes with long needles. However, this technique is relatively slow and thus will result in poor optical properties in QDs. In this work, highly luminescent CdTe QDs were synthesised by transferring hot precursors into each other using cannula method. Unlike regular syringe technique, with the help of high pressure difference between two precursors’ flasks and wide cross-section of cannula, the hot cannulation process is too short which yields narrow size distribution and high quantum yield of CdTe QDs. Here QDs with full width half maximum (FWHM) of 28 nm was achieved. In addition, the photoluminescence quantum yield of our samples was measured to be about 21 ± 0.9 which is at least twice the previous record values for CdTe QDs wherein syringe was used to transfer precursors.

Keywords: CdTe, hot injection method, luminescent, quantum dots

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Authors: Liu Wei-Hsien, Chuang Hsiao-Li, Huang Yen-Te, Wu Chien-Chen, Chou Geng-Ting, Tsai Ying-Chieh

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Intestinal microflora play an important role in communication along the gut-brain axis. Probiotics, defined as live bacteria or bacterial products, confer a significant health benefit to the host. Here we administered Lactobacillus plantarum PS128 (PS128) to the germ-free (GF) mouse to investigate the impact of the gut-brain axis on emotional behavior. Administration of live PS128 significantly increased the total distance traveled in the open field test; it decreased the time spent in the closed arm and increased the time spent and total entries into the open arm in the elevated plus maze. In contrast, heat-killed PS128 caused no significant changes in the GF mice. Treatment with live PS128 significantly increased levels of both serotonin and dopamine in the striatum, but not in the prefrontal cortex or hippocampus. However, live PS128 did not alter pro- or anti-inflammatory cytokine production by mitogen-stimulated splenocytes. The above data indicate that the normalization of emotional behavior correlated with monoamine neurotransmission, but not with immune activity. Our findings suggest that daily intake of the probiotic PS128 could ameliorate neuropsychiatric disorders such as anxiety and excessive psychological stress.

Keywords: dopamine, hypothalamic-pituitary-adrenal axis, intestinal microflora, serotonin

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Authors: Mustafa Abu Ghalia, Yaser Dahman

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A new class of polyurethane (PU) reinforced with green bacterial cellulose nanofibers (BC) were prepared using a solvent casting method, with the goal of fabricating green nanocomposites. Four series classes of BC (1, 2.5, 5, and 10 wt%) were reinforced into PU matrices via BC surface modification and subsequently BC-grafted into PU throughout silane coupling agent to improve BC dispersion and its interfacial interaction. The experiment results from the tensile tester were evaluated according to the response surface method (RSM) for optimizing the impacts of variable parameters, pore size, porosity, and BC contents on the mechanical properties. The compressive strength for PU-5 BC wt% was about 9.8 MPa, and decrease when being generated prosperity to recorded at 4.9 MPa. Nielson model was applied to investigate the BC stress concentration on the PU matrices. Likewise, krenche and Hapli-Tasi model were employed to evaluate the BC nanofiber reinforcement potential and BC orientation into PU matrices. The analysis of variance (ANOVA) demonstrated that only BC loading has a significant effect in increases tensile strength, young’s modulus, and a flexural modulus of the PU-BC nanocomposites. The optimal factors of the variables experiment confirmed to be 5 wt% for BC, 230 for pore size, and 80 % for porosity. Scanning electron microscopy (SEM) micrographs showed that the uniform distribution of nanofibers in the PU matrices with the addition of BC 5 wt %. Hydrolytic degradation revealed that the weight loss in PU-BC scaffold is higher than PU-BC wt %.

Keywords: polyurethane scaffold, mechanical properties, tissue engineering, polyurethane

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Authors: Jake Tempo, Stephen Brough

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Introduction and Objectives: Urine cytology has a role in the diagnosis of urothelial cancer when used alongside cystoscopy and imaging, according to the European Association of Urology guidelines. It also has a role in the surveillance post-treatment of urothelial carcinoma. Collecting and analysing urine cytology is costly and time-consuming. We investigated the use of urine cytology in an Australian regional hospital to determine whether clinicians are following international guidelines. Materials and Methods: We analysed all urine cytology requests performed in an Australian regional hospital between 1st January 2017 and 31st December 2018. We reviewed the indication for urine cytology and the patients’ case notes to determine whether urine cytology changed management. Results: During the two-year study period, 153 patients had urine cytology analysed for a variety of indications. In no cases did cytology change the outcome of patient management significantly. In total, 69 of 153 (41%) urine cytology requests were not supported by urological society guidelines. Fifty requests were for haematuria, and twenty requests were for urothelial cancer surveillance. Seven were analysed for follow-up from previous urological investigations. Nine samples were sent for ureteric obstruction of unknown origin. Conclusion: Urine cytology, even when positive, did not significantly change management for the investigation of potential urothelial cancer, and therefore, its use as a diagnostic tool for this purpose should be reconsidered. Many cytology tests are expensive, unnecessary, and not supported by urological society guidelines.

Keywords: cytology, bladder cancer, urine, urothelial carcinoma

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Authors: Siriporn Okonogi, Temsiri Suwan, Sakornrat Khongkhunthian, Jakkapan Sirithunyalug

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In this study, silver nanoparticles (AgNPs) were prepared using ascorbic acid as a reducing agent and silver nitrate as a precursor. The effects of gelatin (G) on particle characteristics and dental pathogen inhibition were investigated. The spectra of AgNPs and G-AgNPs were compared using UV-Vis and Energy-dispersive X-ray (EDX) spectroscopy. The obtained AgNPs and G-AgNPs showed the maximum absorption at 410 and 430 nm, respectively, and EDX spectra of both systems confirmed Ag element. Scanning electron microscope showed that AgNPs and G-AgNPs were spherical in shape. Particles size, size distribution, and zeta potential were determined using dynamic light scattering approach. The size of AgNPs and G-AgNPs were 56 ± 2.4 and 67 ± 3.6 nm, respectively with a size distribution of 0.23 ± 0.03 and 0.19 ± 0.02, respectively. AgNPs and G-AgNPs exhibited negative zeta potential of 24.1 ± 2.7 mV and 32.7 ± 1.2 mV, respectively. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the obtained AgNPs and G-AgNPs against three strains of dental pathogenic bacteria; Streptococcus gordonii, Streptococcus mutans, and Staphylococcus aureus were determined using broth dilution method. AgNPs and G-AgNPs showed the strongest inhibition against S. gordonii with the MIC of 0.05 and 0.025 mg/mL, respectively and the MBC of 0.1 and 0.05 mg/mL, respectively. Cytotoxicity test of AgNPs and G-AgNPs on human breast cancer cells using MTT assay indicated that G-AgNPs (0.1 mg/mL) was significantly stronger toxic than AgNPs with the cell inhibition of 91.1 ± 5.4%. G-AgNPs showed significantly less aggregation after storage at room temperature for 90 days than G-AgNPs.

Keywords: antipathogenic activity, ascorbic acid, cytotoxicity, stability

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Authors: Simone Medio

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If we observe many modern cities from above, we are typically confronted with a sea of asphalt-clad flat rooftops. In contrast to the modernist expectation of a populated flat roof, flat rooftops in modern multi-story buildings are rarely used. On the contrary, they typify a desolate and abandoned landscape encouraging mechanical system allocation. Flat roof technology continues to be seen as a state-of-fact in most multi-storey building designs and its greening its prevalent environmental justification. This paper aims to seek a change in the approach to flat roofing. It makes a case for the opportunity at hand for architectonically resolute, sheltered, livable spaces that make a better use of the environment at rooftop level. The researcher is looking for the triggers that allow for that change to happen in the design process of case study buildings. The paper begins by exploring Han Slawick covered roof terrace in Amsterdam as a simple and essential example of transforming the flat roof in a usable, inhabitable space. It investigates the design challenges and the logistic, financial and legislative hurdles faced by the architect, and the outcomes in terms of building performance and occupant use and satisfaction. The researcher uses a grounded research methodology with direct interview process to the architect in charge of the building and the building user. Energy simulation tools and calculation of running costs are also used as further means of validating change.

Keywords: environmental design, flat rooftop persistence, roof re-habitation, tectonics

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Authors: Bo-Bin Xiaoa, Chia-Yi Liua

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In the task of searching for anomalous radiation sources, personnel holding radiation detectors to search for radiation sources may be exposed to unnecessary radiation risk, and automated search using machines becomes a required project. The research uses various sophisticated algorithms, which are double Q learning, dueling network, and NoisyNet, of deep reinforcement learning to search for radiation sources. The simulation environment, which is a 10*10 grid and one shielding wall setting in it, improves the development of the AI model by training 1 million episodes. In each episode of training, the radiation source position, the radiation source intensity, agent position, shielding wall position, and shielding wall length are all set randomly. The three algorithms are applied to run AI model training in four environments where the training shielding wall is a full-shielding wall, a lead wall, a concrete wall, and a lead wall or a concrete wall appearing randomly. The 12 best performance AI models are selected by observing the reward value during the training period and are evaluated by comparing these AI models with the gradient search algorithm. The results show that the performance of the AI model, no matter which one algorithm, is far better than the gradient search algorithm. In addition, the simulation environment becomes more complex, the AI model which applied Double DQN combined Dueling and NosiyNet algorithm performs better.

Keywords: double Q learning, dueling network, NoisyNet, source searching

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Authors: Dibyendu Das, Santanu Kumar Pal

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Milk protein lactoferrin (Lf) exhibits potent antibacterial activity due to its interaction with Gram-negative bacterial cell membrane component, lipopolysaccharide (LPS). This paper represents fabrication of new Liquid crystals (LCs) based biosensors to explore the interaction between Lf and LPS. LPS self-assembled at aqueous/LCs interface and orients interfacial nematic 4-cyano-4’- pentylbiphenyl (5CB) LCs in a homeotropic fashion (exhibiting dark optical image under polarized optical microscope). Interestingly, on the exposure of Lf on LPS decorated aqueous/LCs interface, an optical image of LCs changed from dark to bright indicating an ordering alteration of interfacial LCs from homeotropic to tilted/planar state. The ordering transition reflects strong binding between Lf and interfacial LPS that, in turn, perturbs the orientation of LCs. With the help of epifluorescence microscopy, we further affirmed the interfacial LPS-Lf binding event by imaging the presence of FITC tagged Lf at the LPS laden aqueous/LCs interface. Finally, we have investigated the conformational behavior of Lf in solution as well as in the presence of LPS using Circular Dichroism (CD) spectroscopy and further reconfirmed with Vibrational Circular Dichroism (VCD) spectroscopy where we found that Lf undergoes alpha-helix to random coil-like structure in the presence of LPS. As a whole the entire results described in this paper establish a robust approach to envisage the interaction between LPS and Lf through the ordering transitions of LCs at aqueous/LCs interface.

Keywords: endotoxin, interface, lactoferrin, lipopolysaccharide

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Authors: Mst. Tuhina-Khatun, Mohamed Hanafi Musa, Mohd Rafii Yosup, Wong Mui Yun, Md. Aktar-Uz-Zaman, Mahbod Sahebi

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Rice is a staple crop of economic importance of most Asian people, and blast is the major constraints for its higher yield. Heritability of plants traits helps plant breeders to make an appropriate selection and to assess the magnitude of genetic improvement through hybridization. Diversity of crop plants is necessary to manage the continuing genetic erosion and address the issues of genetic conservation for successfully meet the future food requirements. Therefore, an experiment was conducted to estimate heritability and to determine the diversity of 27 blast resistant upland rice genotypes based on 18 quantitative traits using randomized complete block design. Heritability value was found to vary from 38 to 93%. The lowest heritability belonged to the character total number of tillers/plant (38%). In contrast, number of filled grains/panicle, and yield/plant (g) was recorded for their highest heritability value viz. 93 and 91% correspondingly. Cluster analysis based on 18 traits grouped 27 rice genotypes into six clusters. Cluster I was the biggest, which comprised 17 genotypes, accounted for about 62.96% of total population. The multivariate analysis suggested that the genotype ‘Chokoto 14’ could be hybridized with ‘IR 5533-55-1-11’ and ‘IR 5533-PP 854-1’ for broadening the gene pool of blast resistant upland rice germplasms for yield and other favorable characters.

Keywords: blast resistant, diversity analysis, heritability, upland rice

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Authors: Jing Hu, Xiaoping Ouyang

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We develop an optical readout gas chamber based on avalanche-induced scintillation for energetic charged particles track. The gas chamber is equipped with a Single Anode Wires (SAW) structure to produce intensive electric field when the measured particles are of low yield or even single. In the presence of an intensive electric field around the single anode, primary electrons, resulting from the incident charged particles when depositing the energy along the track, accelerate to the anode effectively and rapidly. For scintillation gasses, this avalanche of electrons induces multiplying photons comparing with the primary scintillation excited directly from particle energy loss. The electric field distribution for different shape of the SAW structure is analyzed, and finally, an optimal one is used to study the optical readout performance. Using CF4 gas and its mixture with the noble gas, the results indicate that the optical readout characteristics of the chamber are attractive for imaging. Moreover, images of particles track including single particle track from 5.485MeV alpha particles are successfully acquired. The track resolution is quite well for the reason that the electrons undergo less diffusion in the intensive electric field. With the simple and ingenious design, the optical readout gas chamber has a high sensitivity. Since neutrons can be converted to charged particles when scattering, this optical readout gas chamber can be applied to neutron measurement for dark matter, fusion research, and others.

Keywords: optical readout, gas chamber, charged particle track, avalanche-induced scintillation, neutron measurement

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Authors: Mujeeb Mohd, Aqil Mohd, A. K. Najmi, Akhtar MMohd, Vasim Mohd

Abstract:

Dioscorea deltoidea belongs to the Dioscoreaceae family, is usually found in the north-western Himalayas and some other parts of the world up to an altitude of 1000–3000 m. D. deltoidea commonly known as yam and is an extensively used medicinal plant in the indigenous system of medicine. It has been reported to contain dioscine a steroidal glycoside in higher concentration. In the present investigation, silver nanoparticles (AgNPs) have been synthesized by a simple, efficient, environmentally benevolent and economic microwave-assisted method. Callus culture of D. deltoidea was developed and maintained on Murashige and skooge basal medium supplemented with different combination and concentration of plant growth regulators. Aqueous extract of callus culture was used as the reducing and stabilizing agent. The synthesized nanoparticles have been characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD analysis. The presence of a characteristic surface plasmon resonance (SPR) absorption band at 430 nm in UV–Vis reveals the reduction of silver metal ions into silver nanoparticles. Whereas FTIR analysis was performed to probe the possible functional group involved in the synthesis of AgNPs. Further extract and AgNPs were evaluated for antimicrobial activity against different pathogenic microorganisms.

Keywords: antimicrobial, Dioscorea deltoidea, microwave, silver, nanoparticles

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Authors: Tayebeh Norouzi

Abstract:

This study aims to investigate the acquisition process of intonation. It examines the intonation structure of Tokyo Japanese and its realization by Iranian learners of Japanese. Seven Iranian learners of Japanese, differing in fluency, and two Japanese speakers participated in the experiment. Two sentences were used to test the phonological and phonetic characteristics of lexical pitch-accent as well as the intonation patterns produced by the speakers. Both sentences consisted of similar words with the same number of syllables and lexical pitch-accents but different syntactic structure. Speakers were asked to read each sentence three times at normal speed, and the data were analyzed by Praat. The results show that lexical pitch-accent, Accentual Phrase (AP) and AP boundary tone realization vary depending on sentence type. For sentences of type XdeYwo, the lexical pitch-accent is realized properly. However, there is a rise in AP boundary tone regardless of speakers’ level of fluency. In contrast, in sentences of type XnoYwo, the lexical pitch-accent and AP boundary tone vary depending on the speakers’ fluency level. Advanced speakers are better at grouping words into phrases and produce more native-like intonation patterns, though they are not able to realize downstep properly. The non-native speakers tried to realize proper intonation patterns by making changes in lexical accent and boundary tone.

Keywords: intonation, Iranian learners, Japanese prosody, lexical accent, second language acquisition.

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Authors: Tayyibah Shah Alam, Joe Thomas, Nayantara Shenoy

Abstract:

Presenting a case that we would like to share, the answer is straight forward but the path taken to get to the diagnosis is where it gets interesting. A 31-year-old lady presented to the Rheumatology Outpatient department with left-sided chest pain associated with left-sided elbow joint pain intensifying over the last 2 days. She had been having a prolonged history of chest pain with minimal intensity since 2016. The pain is intermittent in nature. Aggravated while exerting, lifting heavy weights and lying down. Relieved while sitting. Her physical examination and laboratory tests were within normal limits. An electrocardiogram (ECG) showed normal sinus rhythm and a chest X-ray with no significant abnormality was noted. The primary suspicion was recurrent costochondritis. Cardiac blood inflammatory markers and Echo were normal, ruling out ACS. CT chest and MRI Thorax contrast showed small ill-defined STIR hyperintensity with thin peripheral enhancement in the anterior mediastinum in the left side posterior to the 5th costal cartilage and anterior to the pericardium suggestive of changes in the fat-focal panniculitis. Confirming the diagnosis as Epicardial fat necrosis. She was started on Colchicine and Nonsteroidal anti-inflammatory drugs for 2-3 weeks, following which a repeat CT showed resolution of the lesion and improvement in her. It is often under-recognized or misdiagnosed. CT scan was collectively used to establish the diagnosis. Making the correct diagnosis prospectively alleviates unnecessary testing in favor of conservative management.

Keywords: EFN, panniculitis, unknown etiology, recurrent chest pain

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Authors: Mahmood Dehqan, Peyman Peyvasteh

Abstract:

In recent years there has been a growing interest in issues concerning the impact of sociocultural theory (SCT) of learning on different aspects of second/foreign language learning. This study aimed to find the possible effects of sociocultural teaching techniques on reading strategy of EFL learners. Indeed, the present research compared the impact of peer and teacher scaffolding on EFL learners’ reading strategy use across two proficiency levels. To this end, a pre-test post-test quasi-experimental research design was used and two instruments were utilized to collect the data: Nelson English language test and reading strategy questionnaire. Ninety five university students participated in this study were divided into two groups of teacher and peer scaffolding. Teacher scaffolding group received scaffolded help from the teacher based on three mechanisms of effective help within ZPD: graduated, contingent, dialogic. In contrast, learners of peer scaffolding group were unleashed from the teacher-fronted classroom as they were asked to carry out the reading comprehension tasks with the feedback they provided for each other. Results obtained from ANOVA revealed that teacher scaffolding group outperformed the peer scaffolding group in terms of reading strategy use. It means teacher’s scaffolded help provided within the learners’ ZPD led to better reading strategy improvement compared with the peer scaffolded help. However, the interaction effect between proficiency factor and teaching technique was non-significant, leading to the conclusion that strategy use of the learners was not affected by their proficiency level in either teacher or peer scaffolding groups.

Keywords: peer scaffolding, proficiency level, reading strategy, sociocultural theory, teacher scaffolding

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Authors: Yao Song, Danni Cheng, Jianjun Ren

Abstract:

Objectives: We aimed to explore the prognostic effects of absolute values and dynamic changes of common hematological indices on oropharynx squamous cell carcinoma (OPSCC) patients treated with radiation. Methods and materials: The absolute values of white blood cell (WBC), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), hemoglobin (Hb), platelet (Plt), albumin (Alb), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at baseline (within 45 days before radiation), 1-, 3-, 6- and 12-months after the start of radiotherapy were retrospectively collected. Locally-estimated smoothing scatterplots were used to describe the smooth trajectory of each index. A mixed-effect model with a random slope was fitted to describe the changing rate and trend of indices over time. Cox proportional hazard analysis was conducted to assess the correlation between hematological indices and treatment outcomes. Results: Of the enrolled 85 OPSCC patients, inflammatory indices, such as WBC and ALC, dropped rapidly during acute treatment and gradually recovered, while NLR and PLR increased at first three months and subsequently declined within 3-12 months. Higher absolute value or increasing trend of nutritional indices (Alb and Hb) was associated with better prognosis (all p<0.05). In contrast, patients with higher absolute value or upward trend of inflammatory indices (WBC, ANC, Plt, PLR and NLR) had worse survival (all p<0.05). Conclusions: The absolute values and dynamic changes of hematological indices were valuable prognostic factors for OPSCC patients who underwent radiotherapy.

Keywords: hematological indices, oropharyngeal cancer, radiotherapy, NLR, PLR

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Authors: Kwang Yeon Kim

Abstract:

This paper will explore the directly proportional relationship between the influence of Hispanophone media in U.S. markets and Hispanic population growth. Though this growth has origins across south and central America, in U.S. media markets Mexican and Cuban immigrants, have traditionally been considered the most influential. Having endured significant historical discrimination, disparagement, and ethnic framing from conventional Anglophone media, such groups have sought to form their own identities as media consuming and producing Americans of Latin American origin. Although immigrants to the U.S. have traditionally faced obstacles in access to education, children of Mexican-Americans (Chicanos) and Cuban-Americans have made significant progress in overcoming these obstacles, partly explaining their media dominance. This is particularly true in the case of Cuban-Americans, for whom such media presence is not predicted by share of population. By conducting comparative studies of Chicano media and Cuban-Americans media, common ground was found in strategies of reliance on media-driven identity formation. In contrast to the mainstream media portrayal of Latino/as with limiting, negative stereotypes, Spanish-language media’s goal is to form the identity of being Latino for those living in the United States. Providing both news from countries of origin and local news within the United States, Chicano and Cuban-American media performs rituals of recollection while rooting such populations in more proximate media paradigms.

Keywords: Chicano identity, Cuban-Americans, Hispanophone media, Latino/a community

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Authors: Elizabeth Spink

Abstract:

Providing safe and affordable drinking water to low-income households in developing countries remains a challenge. Policy goals of increasing household piped-water access and cost recovery for utility providers are often at odds. Nonpayment of utility bills is frequently cited as a constraint to improving the quality of utility service. However, nonpayment is widely tolerated, and households often accumulate significant debt to the utility provider. This study examines the effect of enforcement of water bill payment through supply disconnections in Livingstone, Zambia. This research uses a dynamic model of household monthly payments and accumulation of arrears, which determine the probability of disconnection, and simulates the effect of exogenous changes in enforcement levels. This model is empirically tested using an event-study framework of exogenous increases in enforcement capacity that occur during administrative rezoning events, which reduce the number of households that one enforcement agent is responsible for. The results show that households are five percentage points more likely to make a payment in the months following a rezoning event, but disconnections for low-income households increase as well, resulting in little change in revenue collected by the water utility. The results suggest that high enforcement of water bill payments toward credit-constrained households may be ineffective and lead to reduced piped-water access.

Keywords: enforcement, nonpayment, piped-water access, water utilities

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Authors: Maryam Zahedifard, Fadhil Lafta Faraj, Maryam Hajrezaie, Nazia Abdul Majid, Mahmood Ameen Abdulla, Hapipah Mohd Ali

Abstract:

In the current study, we prepared two new quinazoline schiff bases through condensation reaction of 2-aminobenzhydrazide with 5-bromosalicylaldehyde and 3-methoxy-5-bromosalicylaldehyde. The chemical structures of both newly synthesized compounds (1 and 2) were confirmed by FT-IR and X-ray crystallography studies. The cytotoxic effect of compounds was investigated against MCF-7 human breast cancer cells. MTT results showed that (1) and (2) decreased the viability of MCF-7 cells in a time-dependent manner, exhibiting an IC50 value of 3.23 ± 0.28 µg/mL and 3.41 ± 0.34 µg/mL, respectively, after a 72-hours treatment period. In contrast, they did not show significant anti-proliferative effect towards MCF-10A normal breast cells and WRL-68 normal liver cells. We found a perturbation in mitochondrial membrane potential and increased cytochrome c release from the mitochondria to the cytosol, suggesting an activation of apoptosis by compounds, which was confirmed by activation of the initiator caspase-9 and the executioner caspases-3/7. (1) was also able to trigger extrinsic pathway via activation of caspase-8 and inhibition of NF-κB translocation. The acute toxicity test showed no toxicity effect of the compounds in rats. Our results showed that the selected synthesized compounds are highly potent to induce apoptosis in MCF-7 cells via either intrinsic or extrinsic mitochondrial pathway.

Keywords: Quinazoline Schiff base, apoptosis, MCF-7 human breast cancer cell line, caspase, NF-κB translocation

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