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Background and aims. Internet addiction (IA) has negative consequences on the mental health and affects daily activities. This study was conducted with the aim to assess the prevalence of Internet addiction among dental university students and to determine if there is any relationship of excessive Internet use with depression and academic performance among students. Methods. This was a cross sectional study which included 384 dental students from different academic years. A questionnaire was prepared that collected information on demographic characteristics, pattern of Internet use, duration of use, and most common mode of Internet access. Internet addiction was assessed using Youngs Internet Addiction test. Depression was assessed using Becks depression inventory [BDI-1]. Results. The prevalence of Internet addiction and depression was found to be 6% and 21.5% respectively. The first year students showed the highest mean Internet addiction (17.42±12.40) score. Chatting was the main purpose for Internet use. Logistic regression analysis showed that individuals who were depressed (Odds Ratio=6.00, p value<0.0001*) and scored less than 60% marks (Odds Ratio=6.71, p value<0.0001*) were more likely to be addicted to Internet. Conclusion. The addiction to internet has negative impact on mental health and academic performance. These high risk group students should be identified and psychological counseling should be provided. [ABSTRACT FROM AUTHOR]

Carbon steel is the most commonly used material in the petroleum industry owing to its high performance and relatively low cost compared with highly alloyed materials. The corrosion resistance of carbon steel in aqueous solutions is dependent on the surface layer created on carbon steel. This layer often consists of siderite (FeCO 3 ) and cementite (Fe 3 C), but it is neither compact nor dense. To improve the carbon steel surface resistance against corrosion and wear, a compact and dense layer can be deposited onto the surface by thermal spray coating. In this research, Al 2 O 3 –40TiO 2 and Cr 3 C 2 –20NiCr were deposited onto mechanical part surfaces by HVOF spray technique. The present study describes and compares the electrochemical behavior of carbon steel, Cr 3 C 2 –20NiCr and Al 2 O 3 –40TiO 2 in 3.5% NaCl using open-circuit potential measurement (OCP) and electrochemical impedance microscopy (EIS) for 36 days. The tribological and mechanical properties are also investigated using a tribometer (pin-on-disc). The results indicate that these chemical composition coatings facilitated significant anti-corrosion and anti-wear improvement. However, the samples coated with Al 2 O 3 –40TiO 2 exhibited the lowest corrosion rate. In terms of wear performance, both coated samples displayed similar behavior under different loads. Scanning electron microscopy (SEM) showed the distinctive microstructure of the HVOF-sprayed samples before and after corrosion and wear testing. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: Radiotherapy differed widely in east and south-east Asia because of technical, cultural, and socio-economic differences. With the purpose of standardizing radiotherapy for cervical cancer in the region, an international clinical study was conducted. Materials and methods: Eleven institutions in eight Asian countries participated in the study. Between 1996 and 1998, 210 patients with stage IIIB cervical cancer were enrolled. Patients were treated with a combination of external beam radiotherapy (total dose, 50Gy) and either high-dose-rate (HDR) or low-dose-rate (LDR) intracavitary brachytherapy (ICBT) according to the institutional practice. The planned point A dose was 20–28Gy/4 fractions for HDR-ICBT and 30–40Gy/1–2 fractions for LDR-ICBT. Results: Hundred patients were treated with HDR-ICBT and 110 were treated with LDR-ICBT. The ICBT doses actually delivered to point A ranged widely: 12–32Gy in the HDR group and 26–52.7Gy in the LDR group. The 5-year follow-up rate among the countries differed greatly, from 29% to 100%. The 5-year major complication rates were 6% in the HDR group and 10% in the LDR group. The 5-year overall survival rates were 51.1% in the HDR group and 57.5% in the LDR group. Conclusions: Although there were several problems with treatment compliance and patients’ follow-up, the study suggests that the protocols provided favorable outcomes with acceptable rates of late complications in the treatment of advanced cervical cancer in east and south-east Asia. [Copyright &y& Elsevier]

Chitosan has attracted much attention for use in antimicrobial food packaging because of its unique antibacterial properties and excellent film-forming ability. However, its poor barrier properties to UV light and high water-solubility limit its application. In this study, modified cellulose nanofiber was incorporated into chitosan films to improve their UV blocking, physical, and antibacterial properties. Modified cellulose nanofiber was obtained by grafting curcumin to 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose. Infrared spectroscopy and X-ray photoelectron spectroscopy results indicated that cellulose was successfully modified. Bio-nanocomposite films composed of chitosan (67–100 wt %) and curcumin grafted TEMPO-oxidized cellulose nanofiber (CGTOCNF, 0–33 wt %) were prepared using the casting method. Scanning electron microscopy images and X-ray diffraction analysis showed that the addition of CGTOCNF noticeably affected the morphology of the composite films, with the crystallinity significantly increasing from 21.93% to 87.15%. Moreover, CGTOCNF incorporation improved the oxidation resistance and UV blocking properties of the composite films compared to pure chitosan films. It is also worth mentioning that all of the composite films have excellent antibacterial activity with CGTOCNF partially replacing chitosan. Furthermore, the water solubility of films decreased with the incorporation of CGTOCNF. However, this study demonstrated that incorporation of CGTOCNF at concentrations greater than 10% resulted in a slight decrease in the water vapor barrier properties and mechanical strength of chitosan films. The findings in this work indicate that the addition of 10% CGTOCNF to chitosan films enhances their physical and antibacterial properties, thus increasing their potential for use in food packaging. Image 1 • Curcumin was grafted into cellulose nanofiber (CGTOCNF) via ester bond. • CGTOCNF incorporation enhanced the UV shielding property of chitosan films. • The composite films had lower water solubility than pure chitosan films. • CGTOCNF did not affect the antibacterial and mechanical properties of films. • The composite films have potential to be used as biodegradable food packaging. [ABSTRACT FROM AUTHOR]

• Novel hybrid rainfall hydropower with solar photovoltaic-battery is introduced. • Photovoltaic-battery and photovoltaic-battery-hydro system are analysed and compared. • Robust energy management is carried out to utilize the excess power for water pumping. • Photovoltaic-battery-hydro and robust energy management reduces levelized cost of energy. • The hybrid photovoltaic-battery-hydro is suiting standalone rural electrification. This paper presents analysis and optimization of standalone hybrid renewable energy system for powering a 3.032 kWh/day housing unit. The hybrid system is strategized to utilize harvesting rainfall and integrating a pumped-hydro storage with a solar photovoltaic-battery system. The optimization, using particle swarm optimization technique, is conceived for minimizing the over sizing of components and secure reliable power supply management with objective function to minimize the levelized cost of energy for loss of power supply probability of 0.0. Four different cases have been optimized, analyzed and compared. Case 1 is a conventional photovoltaic-battery system, Case 2 is photovoltaic-battery integrated with hydro system utilizing only the direct rainfall, Case 3 is photovoltaic-battery integrated with pumped-hydro storage system with the battery bank as the primary power backup, and Case 4 is the photovoltaic-battery integrated with pumped-hydro storage system with hydro system as the primary power backup. Results are revealing that integration of rainfall-based hydropower system of only 100 W with effective water storage of 6.5 m3 at 7.0 m of net water head has resulted in reduction of the installed photovoltaic capacity by about 13.0% compared to power system without rainfall-based hydropower system. The highest hydropower share of 5.0% is observed in Case 4. Case 4 has also resulted in least levelized cost of energy of 0.443 $/kWh. It has been demonstrated that it is possible to achieve environmental appropriateness, reliable and low-cost power generation by integration of harvesting rainfall with photovoltaic-battery system. The suggested system has less dependency on the battery storage as the batteries are the most expensive part with short life span in the proposed integrated renewable systems. [ABSTRACT FROM AUTHOR]

• HPLC-FLD method for BADGE and its derivatives analysis with LOD of 0.01–0.20 ng/g. • The optimization of separation conditions applying DryLab® software. • Adequate separation in 5 min using a core–shell particle column. Bisphenol A diglycidyl ether (BADGE) is used as a raw material for the production of epoxy resins and PVC organosols, which are commonly applied as inner coatings for food cans. BADGE and its derivatives can migrate from coatings to foodstuffs during processing and storage thereby creating adverse health issues. In this work, a method based on high-performance liquid chromatography (HPLC)-fluorescence detection (FLD) method was developed for the rapid determination of BADGE and its five derivatives in canned foods. Modeling software DryLab® was applied for the optimization of separation conditions. An adequate separation was achieved in 5 min including equilibration time, using a core–shell particle column; such application has not been reported so far. Also, the results showed that LOD varied from 0.01 to 0.20 ng/g, while LOQ varied from 0.03 to 0.66 ng/g, and RSD was found to be <8.64%. The analytical recoveries ranged from 70.46 to 103.44%. Excellent validation data revealed that this method is suitable for the investigation of can coating-to-food migration of BADGE and its derivatives. The HPLC-FLD method is rapid, inexpensive and highly efficient, which could be applicable for safety inspection of food contact materials involving BADGE and its derivatives. [ABSTRACT FROM AUTHOR]

We describe a new scaffold-free three-dimensional (3D) cell culture model using cholesteryl ester based lyotropic liquid crystal (LC) substrates. Keratinocytes were deposited randomly on the LC surface where they self-assembled into 3D microtissues or keratinospheroids. The cell density required to form spheroids was optimized. We investigated cell viability using dead/live cell assays. The adhesion characteristics of cells within the microtissues were determined using histological sectioning and immunofluorescence staining. Fourier transform infrared spectroscopy (FTIR) was used to characterize the biochemistry of the keratinospheroids. We found that both cells and microtissues could migrate on the LC surface. The viability study indicated approximately 80% viability of cells in the microtissues up to 20 days of culture. Strong intercellular adhesion was observed in the stratification of the multi-layered microspheroids using field emission-scanning electron microscopy (FE-SEM) and histochemical staining. The cytoskeleton and vinculins of the cells in the microtissues were expressed diffusely, but the microtissues were enriched with lipids and nucleic acids, which indicates close resemblance to the conditions in vivo. The basic 3D culture model based on LC may be used for cell and microtissue migration studies in response to cytochemical treatment.