Comparison of fermentation characteristics of kimchi made with fresh and stored spring kimchi cabbage.

Kimchi cabbage, the main ingredient of kimchi, is often stored to cater for supply issues. However, kimchi made using stored cabbage show different fermentation characteristics from those using fresh cabbage (control kimchi). Herein, sensory evaluation and analysis of viable LAB, microbial communities, and metabolites in two types of kimchi were performed. The fermentation of kimchi made with stored cabbage proceeded slightly faster in the early and mid-fermentation stages than that of control kimchi. And, storage of kimchi cabbage affected the microbial community structure of kimchi, which caused differences in metabolites. In the early stage of kimchi fermentation, fructose and mannitol contents were higher in control kimchi than in kimchi made with stored cabbage, but in the late stage, mannitol and lactic acid contents were higher in kimchi made with stored cabbage. Control kimchi had higher levels of sweetness and texture than kimchi made with stored cabbage. Overall, kimchi made with stored cabbage had different fermentation characteristics compared with control kimchi.

Functionalization of Zinc Oxide Nanoflowers with Palladium Nanoparticles via Microwave Absorption for Room Temperature-Operating Hydrogen Gas Sensors in the ppb Level.

Microwave-assisted functionalization of zinc oxide nanoflowers (ZnO NFs) with palladium nanoparticles (Pd NPs) is demonstrated to realize high-performance chemiresistive-type hydrogen (H2) gas sensors operating at room temperature (RT). The developed gas sensors exhibit a high response of up to 70% at 50 ppm and a theoretical detection limit of 10 ppb. The formation of ZnO NFs with an enhanced specific surface area and their functionalization with Pd NPs are investigated through various characterizations. Furthermore, the optimization of microwave absorption upon the structural incorporations between nanostructures (NF-NPs) is investigated for solution-based functionalization at low temperatures (below 120 °C) for short process times (within 1 min), compared to the conventional thermal annealing at 250 °C for 1 h. Highly sensitive and selective ZnO-based gas sensors enabling the detection of H2 gas molecules at 300 ppb concentration at RT exhibit a short response/recovery time of below 3 min and a good selectivity toward different gases including nitric oxide, carbon monoxide, and oxygen. The successful functionalization of nanostructured metal oxide semiconductors (MOSs) with metal NPs via effective and practical microwave absorption enhances the potential on highly sensitive and selective chemiresistive-type MOS-based gas sensors operating at RT without additional heaters or photogenerators.

Carbon nanotubes: An effective platform for biomedical electronics.

Cylindrical fullerenes (or carbon nanotubes (CNTs)) have been extensively investigated as potential sensor platforms due to effective and practical manipulation of their physical and chemical properties by functionalization/doping with chemical groups suitable for novel nanocarrier systems. CNTs play a significant role in biomedical applications due to rapid development of synthetic methods, structural integration, surface area-controlled heteroatom doping, and electrical conductivity. This review article comprehensively summarized recent trends in biomedical science and technologies utilizing a promising nanomaterial of CNTs in disease diagnosis and therapeutics, based on their biocompatibility and significance in drug delivery, implants, and bio imaging. Biocompatibility of CNTs is essential for designing effective and practical electronic applications in the biomedical field particularly due to their growing potential in the delivery of anticancer agents. Furthermore, functionalized CNTs have been shown to exhibit advanced electrochemical properties, responsible for functioning of numerous oxidase and dehydrogenase based amperometric biosensors. Finally, faster signal transduction by CNTs allows charge transfer between underlying electrode and redox centres of biomolecules (enzymes).

Virtual reality-based measurement of ocular deviation in strabismus.

BACKGROUND AND OBJECTIVE: Strabismus is an eye movement disorder in which shows the abnormal ocular deviation. Cover tests have mainly been used in the clinical diagnosis of strabismus for treatment. However, the whole process depends on the doctor's level of experience, which could be subjected to several factors. In this study, an automated technique for measurement of ocular deviation using a virtual reality (VR) device is developed. METHODS: A VR display system in which the screens that have the fixation target are changed alternately between on and off stages is used to simulate the normal strabismus diagnosis steps. Patients watch special-designed 3D scenes, and their eye motions are recorded by two infrared (IR) cameras. An image-processing-based pupil tracking technique is then applied to track their eye movement. After recording eye motion, two strategies for strabismus angle estimation are implemented: direct measurement and stepwise approximation. The direct measurement converts the eye movement to a strabismus angle after considering the eyeball diameter, while the stepwise approximation measures the ocular deviation through the feedback calibration process. RESULTS: Experiments are carried out with various strabismus patients. The results are compared to those of their doctors' measurement, which shows good agreement. CONCLUSIONS: The results clearly indicate that these techniques could identify ocular deviation with high accuracy and efficiency. The proposed system can be applied in small space and has high tolerance for the unexpected head movements compared with other camera-based system.

Wearable 1 V operating thin-film transistors with solution-processed metal-oxide semiconductor and dielectric films fabricated by deep ultra-violet photo annealing at low temperature.

Amorphous metal-oxide semiconductors (AOSs) such as indium-gallium-zinc-oxide (IGZO) as an active channel have attracted substantial interests with regard to high-performance thin-film transistors (TFTs). Recently, intensive and extensive studies of flexible and/or wearable AOS-based TFTs fabricated by solution-process have been reported for emerging approaches based on device configuration and fabrication process. However, several challenges pertaining to practical and effective solution-process technologies remain to be resolved before low-power consuming AOS-based TFTs for wearable electronics can be realized. In this paper, we investigate the non-thermal annealing processes for sol-gel based metal-oxide semiconductor and dielectric films fabricated by deep ultraviolet (DUV) photo and microwave annealing at low temperature, compared to the conventional thermal annealing at high temperature. A comprehensive investigation including a comparative analysis of the effects of DUV photo and microwave annealing on the degree of metal-oxide-metal networks in amorphous IGZO and high-dielectric-constant (high-k) aluminum oxide (Al2O3) films and device performance of IGZO-TFTs in a comparison with conventional thermal annealing at 400 °C was conducted. We also demonstrate the feasibility of wearable IGZO-TFTs with Al2O3 dielectrics on solution-processed polyimide films exhibiting a high on/off current ratio of 5 × 104 and field effect mobility up to 1.5 cm2/V-s operating at 1 V. In order to reduce the health risk and power consumption during the operation of wearable electronics, the operating voltage of IGZO-TFTs fabricated by non-thermal annealing at low temperature was set below ~1 V. The mechanical stability of wearable IGZO-TFTs fabricated by an all-solution-process except metal electrodes, against cyclic bending tests with diverse radius of curvatures in real-time was investigated. Highly stable and robust flexible IGZO-TFTs without passivation films were achieved even under continuous flexing with a curvature radius of 12 mm.

High-performance gas sensors based on single-wall carbon nanotube random networks for the detection of nitric oxide down to the ppb-level.

We demonstrate highly sensitive and selective gas sensors based on solution-processed single-wall carbon nanotube (SWCNT) random networks for the detection of nitric oxide (NO) down to the ppb-level operating at room temperature. The proposed gas sensors exhibited a response of 50% under both inert and air atmospheres with a theoretical detection limit of 0.2 ppb and a selectivity toward different target gases of volatile organic compounds, including benzene, toluene, and ammonia. The outstanding sensing performance was realized by functionalizing SWCNT random networks with polyethylenimine (PEI), which possesses a repeating structure of amine groups. We investigate the functionalization properties of SWCNT random networks by using atomic force microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy and the sensing mechanism in the proposed NO gas sensors. We note that solution-process technologies, from the deposition of SWCNT random networks to the polymeric functionalization of amine groups, were employed at room temperature under an ambient atmosphere to fabricate highly sensitive and selective NO gas sensors, which are based on low-cost, effective, and scalable merits in the industry of sensors. We also investigate the effect of ultraviolet (UV) irradiation on the recovery time underlying the sensing mechanism. Photodesorption energy obtained by UV irradiation reduced the recovery time of the proposed NO gas sensors to within a few tens of seconds. We believe that this work is a promising and practical approach for realizing health-care monitoring systems by real-time analyzing NO gas at the ppb level in the field of biosensors.

Development of air-blast dried non-Saccharomyces yeast starter for improving quality of Korean persimmon wine and apple cider.

A total of 512 yeasts, including 422 non-Saccharomyces yeasts, were isolated from various fruits including apple, aronia, Muscat Bailey A grapes, and persimmon. These were used to prepare persimmon wine and apple cider starters that produced high levels of aromatic compounds, which contribute to high-quality fermented products. Environmental tolerance testing with 20% glucose and 8% EtOH, alongside a sniffing test, led to the selection of Wickerhamomyces anomalus (Synonym Pichia anomala) SJ20, Meyerozyma caribbica (Synonym Pichia caribbica) YP1, Pichia kluyveri CD34, Hanseniaspora uvarum SJ69 (for persimmon wine), W. anomalus CS7-16 (for apple cider), and Starmerella bacillaris (Synonym Candida zemplinina) CD80 (for both wines) as wine starters. These strains had high environmental stress tolerance and the highest sniffing test scores. Persimmon wine and apple cider were fermented using these strains in single- or mixed-culture with S. cerevisiae W-3 to determine the improved effect on wine aroma. In accordance with the results of volatile ester compounds and sensory evaluation, W. anomalus SJ20, H. uvarum SJ69, and W. anomalus CS7-16 had an excellent potential as persimmon wine and apple cider starters. Moreover, other strains also showed a good potential for a distinctive persimmon wine and apple cider because of the different compositions of the various volatile ester compounds. Six types of sugars (fructose, glucose, maltose, sucrose, raffinose, sucrose, and trehalose), four types of rehydration solutions (distilled water, 1× phosphate buffered saline, 0.85% NaCl, and 1% peptone water), and two types of antioxidants (l-ascorbic acid and glutathione) were examined to improve the survival rate of air-blast dried non-Saccharomyces yeast cells. Optimal sugar and rehydration conditions for each strain were validated, and scanning electron microscopy showed that each cell was surrounded by protectants, including sugar, skim milk, and lactomil. Storability assessment of air-blast dried yeast cells maintained at 4 °C for two months indicated that at least one condition in each strain had a higher survival rate than the control, regardless of the concentration or type of antioxidant treatment, except for M. caribbica YP1. These results suggest that antioxidant treatment contributes to maintaining the viability of air-blast dried cells in hostile environments.

Functionalized Carbon Nanotube Sensors for the Detection of Sub-ppm Nitric Oxide Gas.

In this paper, we demonstrate the highly sensitive carbon nanotube (CNT) sensors for the detection of sub-ppm nitric oxide (NO) gas operating at room temperature. Such achievement can be realized by functionalizing CNT thin films with amine-based polymers through a solution-process technology at low temperature. In addition to high sensitivity, functionalized CNT sensors exhibit high selectivity towards NO gas, which is an effective and practical factor for health-care monitoring nano-electronics. We also investigated the effect of a post-cleaning treatment on the sensing performance of functionalized CNT thin films for sub-ppm NO gas sensors. We believe that this work can open-up new routes to realize high performance human-interactive electronics for respiratory diseases detection in exhaled air.

Waterproof Electronic-Bandage with Tunable Sensitivity for Wearable Strain Sensors.

We demonstrate high-performance wearable electronic-bandage (E-bandage) based on carbon nanotube (CNT)/silver nanoparticle (AgNP) composites covered with flexible media of fluoropolymer-coated polydimethylsiloxane (PDMS) films. The E-bandage can be used for motion-related sensors by directly attaching them to human skin, which achieves a fast and accurate electric response with high sensitivity according to the bending and stretching movements that induce changes in the conductivity. This advance in the E-bandage is realized as a result of the sensitivity that can be achieved by controlling the concentration of AgNPs in CNT pastes and by modifying the device architecture. The fluoropolymer encapsulation with hydrophobic surface characteristics allows for the E-bandage to operate in water and protects it from physical and chemical contact with the daily life conditions of the human skin. The reliability and scalability of the E-bandage as well as the compatibility with conventional microfabrication allow new possibilities to integrate flexible human-interactive nanoelectronics into mobile health-care monitoring systems combined with Internet of things (IoTs).

Formulation of a modified-release pregabalin tablet using hot-melt coating with glyceryl behenate.

A modified-release (MR) tablet of the anti-anxiety drug pregabalin (PRE) was prepared by hot-melt coating PRE with glyceryl behenate (GB) as a release retardant and compressing to form a matrix with microcrystalline cellulose (MCC) as a hydrophilic diluent. GB-coated PRE had a size in the range of 177-290 µm with good to acceptable flowability. Tablet hardness decreased slightly as GB content increased. PRE release from the tablet matrices was successfully modified by altering the ratio of MCC and GB, and it was found that dissolution- or diffusion-controlled release depended on the amount of GB used. Drug release was pH-independent. An accelerated stability test on the most promising MR tablet at 40°C and 75% relative humidity for 6 months showed no significant changes in PRE content, and the occurrence of total impurities--including PRE-lactam--was within acceptable limits. After oral administration of the selected MR tablet or a commercial IR capsule (Lyrica) to healthy human volunteers, pharmacokinetic parameters including Tmax, Cmax, AUC0-24, and T1/2 were compared. The confidence interval of AUC0-24 was within the adequate range, but that of Cmax was inadequate. This study demonstrated the potential use of GB for PRE-containing MR formulations.

Appraisal of within- and between-laboratory reproducibility of non-radioisotopic local lymph node assay using flow cytometry, LLNA:BrdU-FCM: comparison of OECD TG429 performance standard and statistical evaluation.

Mouse local lymph node assay (LLNA, OECD TG429) is an alternative test replacing conventional guinea pig tests (OECD TG406) for the skin sensitization test but the use of a radioisotopic agent, (3)H-thymidine, deters its active dissemination. New non-radioisotopic LLNA, LLNA:BrdU-FCM employs a non-radioisotopic analog, 5-bromo-2'-deoxyuridine (BrdU) and flow cytometry. For an analogous method, OECD TG429 performance standard (PS) advises that two reference compounds be tested repeatedly and ECt(threshold) values obtained must fall within acceptable ranges to prove within- and between-laboratory reproducibility. However, this criteria is somewhat arbitrary and sample size of ECt is less than 5, raising concerns about insufficient reliability. Here, we explored various statistical methods to evaluate the reproducibility of LLNA:BrdU-FCM with stimulation index (SI), the raw data for ECt calculation, produced from 3 laboratories. Descriptive statistics along with graphical representation of SI was presented. For inferential statistics, parametric and non-parametric methods were applied to test the reproducibility of SI of a concurrent positive control and the robustness of results were investigated. Descriptive statistics and graphical representation of SI alone could illustrate the within- and between-laboratory reproducibility. Inferential statistics employing parametric and nonparametric methods drew similar conclusion. While all labs passed within- and between-laboratory reproducibility criteria given by OECD TG429 PS based on ECt values, statistical evaluation based on SI values showed that only two labs succeeded in achieving within-laboratory reproducibility. For those two labs that satisfied the within-lab reproducibility, between-laboratory reproducibility could be also attained based on inferential as well as descriptive statistics.

Reliability and validity of the Korean version of the trunk control measurement scale (TCMS-K) for children with cerebral palsy.

The Trunk Control Measurement Scale (TCMS) was developed by Lieve Heyrman in 2011 to evaluate the clinical features of impaired trunk control ability in patients with cerebral palsy (CP). This study aimed to demonstrate the reliability and validity of the Korean version of the Trunk Control Measurement Scale (TCMS-K) for children with CP. Fifty children with spastic CP (mean age 9.08±3.75) participated in the study. They were classified using the Gross Motor Function Classification System and the Manual Ability Classification System. The intraclass correlation coefficient (ICC) value of the inter-rater reliability for the TCMS-K was .987-.998, and the intra-rater reliability was .947-.996. The Spearman rank correlation coefficient between the TCMS-K and the Gross Motor Function Measure-B dimension was .860. The results of the study support that the TCMS-K has a high reliability and validity, which is similar to the original version. Thus, the TCMS-K is a suitable evaluation tool to assess the qualitative performance of trunk control and sitting balance for children with CP, and we expect that it will be a very useful tool for clinicians and researchers.