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The objective of this study is to estimate the occurrence probabilities of severe accident phenomena based on a fuzzy elicitation technique. Normally, it is difficult to determine these probabilities due to the lack of information on severe accident progression and the highly uncertain values currently in use. In this case, fuzzy set theory (FST) can be best exploited. First, questions were devised for expert elicitation on technical issues of severe accident phenomena. To deal with ambiguities and the imprecision of previously developed (reference) probabilities, fuzzy aggregation methods based on FST were employed to derive the occurrence probabilities of severe accidents via four phases: 1) choosing experts, 2) quantifying weighting factors for the experts, 3) aggregating the experts’ opinions, and 4) defuzzifying the fuzzy numbers. In this way, this study obtained expert elicitation results in the form of updated occurrence probabilities of severe accident phenomena in the OPR-1000 plant, after which the differences between the reference probabilities and the newly acquired probabilities using fuzzy aggregation were compared, with the advantages of the fuzzy technique over other approaches explained. Lastly, the impact of applying the updated severe accident probabilities on containment integrity was quantitatively investigated in a Level 2 PSA model.

AIM To evaluate whether the use of non-thermal plasma (NTP) could reduce triethylene glycol dimethacrylate (TEGDMA)-mediated damage in MDPC-23 cells. METHODOLOGY The effects of NTP and TEGDMA on MDPC-23 cell proliferation were tested using WST-1 assays after pretreatment with NTP for 1 min and exposure to TEGDMA. Live/Dead assays were used to visualize cell death. To monitor the effects of NTP and TEGDMA on the cell cycle and apoptotic cell death, flow cytometry was performed. Western blotting was used to assess changes in protein levels mediated by NTP and TEGDMA treatment, and enzyme-linked immunosorbent assays were performed to evaluate the effects of NTP and TEGDMA on prostaglandin E2 (PGE2 ) expression. One-way analysis of variance and Duncan's post hoc tests were used for statistical analysis. RESULTS NTP treatment effectively protected cells from TEGDMA-mediated cell damage and blocked TEGDMA-mediated cell growth inhibition (p

Linear viscoelastic region is important to investigate material properties. We investigated boundary of linear viscoelasticity for simple shear flows with various time functions of shear strain. We used Phan-Thien and Tanner (PTT) model and Giesekus model in order to extract the linearity criterion. We determined critical strain (γc) as a function of dimensionless number such as De or Wi and the nonlinear parameter of the models. We found a superposition of the critical strain at start-up shear flow and oscillatory shear flow. Replacing relaxation time by mean relaxation time ( $$\left({\overline {\rm{\lambda }} = {J_{\rm{e}}}{{\rm{\eta }}_{\rm{o}}}} \right)$$ ), we checked the validity of the equation with experimental data.

There is an unmet need for novel, non-pharmacological therapeutics to treat alopecia. Recent studies have shown the potential biological benefits of non-thermal atmospheric pressure plasma (NTAPP), including wound healing, angiogenesis, and the proliferation of stem cells. We hypothesized that NTAPP might have a stimulatory effect on hair growth or regeneration. We designed an NTAPP-generating apparatus which is applicable to in vitro and in vivo experiments. The human dermal papilla (DP) cells, isolated fresh hair follicles, and mouse back skin were exposed with the NTAPP. Biological outcomes were measured using RNA-sequencing, RT-PCR, Western blots, and immunostaining. The NTAPP treatment increased the expression levels of Wnt/β-catenin pathway-related genes (AMER3, CCND1, LEF1, and LRG1) and proteins (β-catenin, p-GSK3β, and cyclin D1) in human DP cells. In contrast, inhibitors of Wnt/β-catenin signaling, endo-IWR1 and IWP2, attenuated the levels of cyclin D1, p-GSK3β, and β-catenin proteins induced by NTAPP. Furthermore, we observed that NTAPP induced the activation of β-catenin in DP cells of hair follicles and the mRNA levels of target genes of the β-catenin signaling pathway (CCND1, LEF1, and TCF4). NTAPP-treated mice exhibited markedly increased anagen induction, hair growth, and the protein levels of β-catenin, p-GSK3β, p-AKT, and cyclin D1. NTAPP stimulates hair growth via activation of the Wnt/β-catenin signaling pathway in DP cells. These findings collectively suggest that NTAPP may be a potentially safe and non-pharmacological therapeutic intervention for alopecia.

Passive cooling based on natural circulation is utilized in ex-vessel core catcher system of an advanced nuclear reactor to handle severe accident scenario. The core catcher coolant channel has a unique geometry which consists of heated downward-facing slightly inclined and vertical surfaces. A full height experimental facility with natural circulation driven flow to model ex-vessel core catcher system was designed using scaling analysis. In this study, the cooling capability and heat transfer characteristics of the ex-vessel core catcher system was carried out. Two-phase flow parameters and wall temperatures were measured under a uniform heat flux condition. Two-phase flow structures were identified by high-speed camera visualization along with measurements of two local parameters, void fraction and re-wetting time. The wall temperature and local heat transfer coefficient distribution along the cooling channel were obtained by direct measurements of the heater surface and liquid temperature. The cooling performance of the core catcher system was analyzed based on the experimental results. The results indicated that the core catcher coolant system provides adequate cooling and maintains the integrity of the core catcher plate for prototype heat flux conditions.

Flow boiling experiments were carried out with water on a 300 mm × 120 mm area and 85 mm thick downward-facing heated copper block at 1.4 bar pressure in a channel inclined 10° upwards with respect to horizontal. Heat transfer studies were conducted on a plain and microporous coated surfaces with heat fluxes up to 550 kW/m2 for various flow rates and subcoolings. The results showed enhanced heat transfer coefficient on the microporous coated surface by a factor of two compared to the plain surface. Flow visualization study indicated that this heat transfer enhancement is due to enhanced microbubble generation on the microporous coated surface. Boiling curves were compared with the ones obtained from the small size heaters from previous researches. The local dryout or local critical heat flux was observed on the plain surface at around 450 kW/m2. When heat flux was increased beyond the critical heat flux level, transition boiling occurred instead of direct excursion to the film boiling. Visualization studies of transition and film boiling regions were also carried out and were analyzed using transient temperature data.

Hepatocellular carcinoma (HCC) is a major histological subtype of primary liver cancer. Ample evidence suggests that the pathological properties of HCC originate from hepatic cancer stem cells (CSCs), which are responsible for carcinogenesis, recurrence, and drug resistance. Cold atmospheric-pressure plasma (CAP) and plasma-activated medium (PAM) induce apoptosis in cancer cells and represent novel and powerful anti-cancer agents. This study aimed to determine the anti-cancer effect of CAP and PAM in HCC cell lines with CSC characteristics. We showed that the air-based CAP and PAM selectively induced cell death in Hep3B and Huh7 cells with CSC characteristics, but not in the normal liver cell line, MIHA. We observed both caspase-dependent and -independent cell death in the PAM-treated HCC cell lines. Moreover, we determined whether combinatorial PAM therapy with various anti-cancer agents have an additive effect on cell death in Huh7. We found that PAM highly increased the efficacy of the chemotherapeutic agent, cisplatin, while enhanced the anti-cancer effect of doxorubicin and the targeted-therapy drugs, trametinib and sorafenib to a lesser extent. These findings support the application of CAP and PAM as anti-cancer agents to induce selective cell death in cancers containing CSCs, suggesting that the combinatorial use of PAM and some specific anti-cancer agents is complemented mechanistically.

Due to the rapid development of mobile phone technology, we are continuously exposed to 1.7 GHz LTE radio frequency electromagnetic fields (RF-EMFs), but their biological effects have not been clarified. Here, we investigated the non-thermal cellular effects of these RF-EMFs on human cells, including human adipose tissue-derived stem cells (ASCs), Huh7 and Hep3B liver cancer stem cells (CSCs), HeLa and SH-SY5Y cancer cells, and normal fibroblast IMR-90 cells. When continuously exposed to 1.7 GHz LTE RF-EMF for 72 h at 1 and 2 SAR, cell proliferation was consistently decreased in all the human cells. The anti-proliferative effect was higher at 2 SAR than 1 SAR and was less severe in ASCs. The exposure to RF-EMF for 72 h at 1 and 2 SAR did not induce DNA double strand breaks or apoptotic cell death, but did trigger a slight delay in the G1 to S cell cycle transition. Cell senescence was also clearly observed in ASC and Huh7 cells exposed to RF-EMF at 2 SAR for 72 h. Intracellular ROS increased in these cells and the treatment with an ROS scavenger recapitulated the anti-proliferative effect of RF-EMF. These observations strongly suggest that 1.7 GHz LTE RF-EMF decrease proliferation and increase senescence by increasing intracellular ROS in human cells.

Non-thermal atmospheric pressure plasma (NTAPP) has been reported to induce wound healing, activation of immune cells, and proliferation of mesoderm-derived adult stem cells in human. However, the mechanism by which NTAPP activates these physiological effects is poorly understood. Here, we examined whole genome expression profiles of adipose tissue-derived stem cells (ASCs), the proliferation of which is induced by NTAPP. NTAPP upregulated the expression of genes for cytokine and growth factor, but downregulated genes in apoptotic pathways. When ASCs were treated with NTAPP in the presence of a nitric oxide (NO) scavenger, the expression of various cytokines and growth factors decreased, suggesting that NO is primarily responsible for the enhanced cytokine and growth factor expression induced by NTAPP. Increased histone deacetyl transferase 1 (HDAC1) and decreased acetylated histone 3 were detected in NTAPP-treated ASCs. Similarly, ASCs pre-treated with HDAC, DNA methylation, or histone methylation inhibitors had reduced expression of cytokines and growth factors after NTAPP treatment. Taken together, these results strongly suggest that NTAPP induces epigenetic modifications that activate the expression of cytokines and growth factors, explaining how NTAPP acts as an efficient tool in regenerative medicine to stimulate stem cell proliferation, to activate immune cells, and to recover wounds.

Non-thermal plasma (NTP) has several beneficial effects, and can be applied as a novel instrument for skin treatment. Recently, many types of NTP have been developed for potential medical or clinical applications, but their direct effects on skin activation remain unclear. In this study, the effect of NTP on the alteration of mouse skin tissue was analyzed. After NTP treatment, there were no signs of tissue damage in mouse skin, whereas significant increases in epidermal thickness and dermal collagen density were detected. Furthermore, treatment with NTP increased the expression of various growth factors, including TGF-α, TGF-β, VEGF, GM-CSF, and EGF, in skin tissue. Therefore, NTP treatment on skin induces the expression of growth factors without causing damage, a phenomenon that might be directly linked to epidermal expansion and dermal tissue remodeling.

Cold atmospheric pressure plasma (CAP) and plasma-activated medium (PAM) induce cell death in diverse cancer cells and may function as powerful anti-cancer agents. The main components responsible for the selective anti-cancer effects of CAP and PAM remain elusive. CAP or PAM induces selective cell death in hepatocellular carcinoma cell lines Hep3B and Huh7 containing populations with cancer stem cell markers. Here, we investigated the major component(s) of CAP and PAM for mediating the selective anti-proliferative effect on Hep3B and Huh7 cells. The anti-proliferative effect of CAP was mediated through the medium, however, the reactive oxygen species scavenger N-acetyl cysteine did not suppress PAM-induced cell death. Neither high concentrations of nitrite or nitrite/nitrate nor a low concentration of H2O2 present in the PAM containing sodium pyruvate affected the viability of Hep3B and Huh7 cells. Inhibitors of singlet oxygen, superoxide anions, and nitric oxide retained the capacity of PAM to induce anti-cancer effects. The anti-cancer effect was largely blocked in the PAM prepared by placing an aluminum metal mesh, but not a dielectric PVC mesh, between the plasma source and the medium. Hence, singlet oxygen, hydrogen peroxide, nitric oxide, and nitrite/nitrate are not the main factors responsible for PAM-mediated selective death in Hep3B and Huh7 cells. Other factors, such as charged particles including various ions in CAP and PAM, may induce selective anti-cancer effects in certain cancer cells.

Stathmin/oncoprotein18 regulates microtubule dynamics and participates in mitotic entry and exit. We isolated stathmin as a physically interacting partner of KIFC1, a minus-end-directed kinesin functioning in bipolar spindle formation and maintenance. We found that stathmin depletion leads to multipolar spindle formation in IMR-90 normal human fibroblasts. Stathmin-depleted IMR-90 cells showed early mitotic delay but managed to undergo chromosome segregation by forming multiple poles or pseudo-bipoles. Consistent with these observations, lagging chromosomes and micronuclei were elevated in stathmin-depleted IMR-90 cells, demonstrating that stathmin is essential for maintaining genomic stability during mitosis in human cells. Genomic instability induced by stathmin depletion led to premature senescence without any indication of cell death in normal IMR-90 cells. Double knock-down of both stathmin and p53 also did not induce cell death in IMR-90 cells, while the stathmin knock-down triggered apoptosis in p53-proficient human lung adenocarcinoma cells. Our results suggest that stathmin is essential in bipolar spindle formation to maintain genomic stability during mitosis, and the depletion of stathmin prevents the initiation of chromosome instability by inducing senescence in human normal fibroblasts. This article is protected by copyright. All rights reserved

Alzheimer’s disease (AD) is a neurodegenerative disease leading to progressive loss of memory and other cognitive functions. One of the well-known pathological markers of AD is the accumulation of amyloid-beta protein (Aβ), and its plaques, in the brain. Recent studies using Tg-5XFAD mice as a model of AD have reported that exposure to radiofrequency electromagnetic fields (RF-EMF) from cellular phones reduced Aβ plaques in the brain and showed beneficial effects on AD. In this study, we examined whether exposure to 1950 MHz RF-EMF affects Aβ processing in neural cells. We exposed HT22 mouse hippocampal neuronal cells and SH-SY5Y human neuroblastoma cells to RF-EMF (SAR 6 W/kg) for 2 h per day for 3 days, and analyzed the mRNA and protein expression of the key genes related to Aβ processing. When exposed to RF-EMF, mRNA levels of APP, BACE1, ADAM10 and PSEN1 were decreased in HT22, but the mRNA level of APP was not changed in SH-SY5Y cells. The protein expression of APP and BACE1, as well as the secreted Aβ peptide, was not significantly different between RF-EMF–exposed 7w-PSML, HT22 and SH-SY5Y cells and the unexposed controls. These observations suggest that RF-EMF exposure may not have a significant physiological effect on Aβ processing of neural cells in the short term. However, considering that we only exposed HT22 and SH-SY5Y cells to RF-EMF for 2 h per day for 3 days, we cannot exclude the possibility that 1950 MHz RF-EMF induces physiological change in Aβ processing with long-term and continuous exposure.

The objectives of this study were to develop and compare sensory characteristics of beverages and soups thickened with different concentrations of a xanthan gum-based thickener, and to examine, using rheological measurement, whether the viscosity of the thickened liquids conformed to the recommendations of the National Dysphagia Diet (NDD) Task Force. Beverages tested included water, apple juice, orange juice, soymilk, and Yakult. The thickening agent was added to samples at concentrations of 1, 2, or 3%. Addition of the thickening agent had a significant effect on the appearance, texture, and starchy flavor, which were evaluated by descriptive sensory evaluation. The reference standards of viscosity used in sensory descriptive analysis could be useful to practitioners who have to make dysphagia diets and need to learn to make them properly. In rheological measurement, viscosity of thickened liquids in stationary state would be perceived as higher compared to that while swallowing, because of the shear thinning property. This could lead to noncompliance of the medical advice or malnutrition. It is necessary to determine optimal proportion of xanthan gum-based thickener or uncover alternatives, which have shear thinning properties lower than those of xanthan gum, for the acceptance of dysphagia patients. There was no pudding-like viscosity as classified by NDD, when prepared following instructions. Future studies should include higher concentrations of thickener to find out the concentration of the thickener resulting in pudding-like viscosity as recommended by NDD. Practical applications When a manufacturer modifies or develops a xanthan gum-based thickener, findings from this study can be utilized to understand sensory and rheological characteristics of thickened liquid. For practitioners who have to make dysphagia diets, the reference standards of viscosity used in sensory descriptive analysis could be helpful for deciding the viscosity level of thickened liquids based only on visual evaluation. This study suggests manufacturers should provide clear direction for viscosity range and thickener concentration. Medical doctors should pay close attention to the risk of aspiration when prescribing pudding-like viscosity. Dietitians should understand the variability in achieving different levels of viscosity and should educate preparers who are responsible for making dysphagia meals.

Ex-vessel core catcher cooling system driven by natural circulation is designed using a full scaled air-water system. A transparent half symmetric section of a core catcher coolant channel of a pressurized water reactor was designed with instrumentations for local void fraction measurement and flow visualization. Two designs of air-water top separator water tanks are studied including one with modified ‘super-step’ design which prevents gas entrainment into down-comer. In the experiment air flow rates are set corresponding to steam generation rate for given corium decay power. Measurements of natural circulation flow rate, spatial local void fraction distribution and re-wetting time near the top wall are carried out for various air flow rates which simulate boiling-induced vapor generation. Since heat transfer and critical heat flux are strongly dependent on the water mass flow rate and development of two-phase flow on the heated wall, knowledge of two-phase flow characteristics in the coolant channel is essential. Results on flow visualization showing two phase flow structure specifically near the high void accumulation regions, local void profiles, rewetting time, and natural circulation flow rate are presented for various air flow rates that simulate corium power levels. The data are useful in assessing the cooling capability of and safety of the core catcher system.

Melanomas are fast growing high-mortality tumors, and specific treatments for melanomas are needed. Melanoma cells overexpress focal adhesion kinase (FAK) compared to normal keratinocytes, and we sought to exploit this difference to create a selectively lethal therapy. We combined gold nanoparticles (GNP) with antibodies targeting phosphorylated FAK (p-FAK). These conjugates (p-FAK-GNP) entered G361 melanoma cells and bound p-FAK. Treatment with p-FAK-GNP decreased the viability of G361 cells in a time dependent manner by inducing apoptosis. To maximize the preferential killing of G361 cells, non-thermal atmospheric pressure plasma was used to stimulate the GNP within p-FAK-GNP. Combined treatment with plasma and p-FAK-GNP showed much higher lethality against G361 cells than HaCaT keratinocyte cells. The p-FAK-GNP induced apoptosis over 48 hours in G361 cells, whereas plasma and p-FAK-GNP killed G361 cells immediately. This study demonstrates that combining plasma with p-FAK-GNP results in selective lethality against human melanoma cells.

The eradication of bacteria from wound sites and promotion of healing are essential for treating infected wounds. Nitric oxide (NO) is desirable for these purposes due to its ability to accelerate wound healing and its broad-spectrum antibacterial effects. We developed an in situ hydrogel-forming/NO-releasing powder dressing (NO/GP), which is a powder during storage and forms a hydrogel when applied to wounds, as a novel NO-releasing formulation to treat infected wounds. An NO/GP fine powder (51.5 &mu, m) was fabricated by blending and micronizing S-nitrosoglutathione (GSNO), alginate, pectin, and polyethylene glycol (PEG). NO/GP remained stable for more than four months when stored at 4 or 37 &deg, C. When applied to wounds, NO/GP absorbed wound fluid and immediately converted to a hydrogel. Additionally, wound fluid triggered a NO release from NO/GP for more than 18 h. The rheological properties of hydrogel-transformed NO/GP indicated that NO/GP possesses similar adhesive properties to marketed products (Vaseline). NO/GP resulted in a 6-log reduction in colony forming units (CFUs) of methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, which are representative drug-resistant gram-positive and -negative bacteria, respectively. The promotion of wound healing by NO/GP was demonstrated in mice with full-thickness wounds challenged with MRSA and P. aeruginosa. Thus, NO/GP is a promising formulation for the treatment of infected wounds.

In the present study, the core flow distribution of research reactors that used a plate-type fuel was investigated by measuring the flow rates at all fuel assembly locations to determine the flow uniformity in the reactor core. A specially instrumented dummy fuel assembly called probe fuel was developed to measure the flow rate at each fuel assembly location. The probe fuel is exactly the same as the real one, except the pressure taps and the embedded pressure conduits for measuring the pressure drop. First, hydraulic experiments were conducted to find out the pressure drop dependency on the flow rate of the probe fuel in a single fuel assembly test loop. Three correlations between the pressure drop and flow rate, which considers the water temperature effect, were derived from the measurement data of the hydraulic experiments. Using the probe fuel, the flow rates of all fuel assembly locations in the research reactor core were obtained from the measured pressure drop of the probe fuel using the correlations. The investigation of the core flow distribution in the downward forced-cooled research reactor was performed under a nominal flow condition. The flow rate measurements at each fuel assembly location were conducted for two vertical control absorber rod (CAR) positions. The measurement results showed that the primary coolant flow in the reactor core was distributed evenly with a small deviation of −2.9%~+2.3%, even though the CAR position changed. However, the ratio of the core flow and the bypass flow in the reactor was changed slightly with the position of the CARs, which seemed to be due to the changes in the flow resistance depending on the CARs’ position. In addition, the total flow rate of the primary cooling system (PCS) also increased a little when the condition of the CARs was fully withdrawn.

Coordination and cross talks of MAPK pathways are critical for signaling efficiency, but their mechanisms are not well understood. Slt2, the MAP kinase of cell wall integrity pathway (CWI), is activated by heat stress even in the absence of upstream components of this pathway, suggesting a supplementary input for Slt2 activation. Here, we identify a new interaction of Ste11 and Mkk1, mediated by Nst1 that connects the high-osmolarity glycerol and pheromone pathways directly to CWI pathway in response to heat and pheromone. We suggest that Ser(407) and Thr(411) are novel residues of Mkk1 activated by these MAPK pathways.

The objective of the present study is to systematically elucidate the time-dependent rheological behavior of concentrated xanthan gum systems in complicated step-shear flow fields. Using a strain-controlled rheometer (ARES), step-shear flow behaviors of a concentrated xanthan gum model solution have been experimentally investigated in interrupted shear flow fields with a various combination of different shear rates, shearing times and rest times, and step-incremental and step-reductional shear flow fields with various shearing times. The main findings obtained from this study are summarized as follows. (i) In interrupted shear flow fields, the shear stress is sharply increased until reaching the maximum stress at an initial stage of shearing times, and then a stress decay towards a steady state is observed as the shearing time is increased in both start-up shear flow fields. The shear stress is suddenly decreased immediately after the imposed shear rate is stopped, and then slowly decayed during the period of a rest time. (ii) As an increase in rest time, the difference in the maximum stress values between the two start-up shear flow fields is decreased whereas the shearing time exerts a slight influence on this behavior. (iii) In step-incremental shear flow fields, after passing through the maximum stress, structural destruction causes a stress decay behavior towards a steady state as an increase in shearing time in each step shear flow region. The time needed to reach the maximum stress value is shortened as an increase in step-increased shear rate. (iv) In step-reductional shear flow fields, after passing through the minimum stress, structural recovery induces a stress growth behavior towards an equilibrium state as an increase in shearing time in each step shear flow region. The time needed to reach the minimum stress value is lengthened as a decrease in step-decreased shear rate.

Adult stem cells are capable of self-renewal and differentiation into specific cell types in tissues and have high potential for stem cell therapy. Mesenchymal and hematopoietic stem cells are easily attainable from the human body and have become applicable tools for adult stem cell therapy. However, there are still technical barriers for the application of mesenchymal and hematopoietic stem cells for therapy, such as the small number of cell populations, high risk of contamination, and loss of their stemness properties in vitro. In our previous study, we showed that non-thermal atmospheric pressure plasma (NTAPP) promoted the proliferation of adipose tissue-derived stem cells (ASCs) by 1.6-fold on average, while maintaining their stemness. Here, we examined the feasibility of NTAPP as a tool to activate the proliferation of mesenchymal and hematopoietic stem cells in vitro without affecting their stem cell characteristics. NTAPP increased the proliferation of bone marrow-derived stem cells (BM-MSCs) and hematopoietic stem cells (HSCs) by 1.8- and 2-fold, respectively, when compared to that of untreated cells. As observed in ASCs, NTAPP exposure also activated the expression of stem cell-specific surface markers, CD44 and CD105, by 5-fold in BM-MSCs, when compared to that in unexposed control cells in a low glucose medium with a low concentration of basic fibroblast growth factor (b-FGF). In addition, NTAPP exposure highly augmented the mRNA expression of well-known pluripotent genes for stemness, such as Oct4, Sox2, and Nanog in ASCs and BM-MSCs when compared to that in unexposed control cells. When cell cycle progression was examined, the G1-S shift was accelerated, and expression of PCNA was increased in NTAPP-exposed ASCs when compared to that in untreated control cells, suggesting that NTAPP activated G1-S transition. Taken together, these results demonstrated that NTAPP activated the proliferation of various mesodermal-derived human adult stem cells by accelerating the G1-S transition while maintaining their pluripotency and stemness, strongly suggesting that NTAPP can be an efficient tool for expanding the population of various adult stem cells in vitro for medical applications.

The objective of the present study is to experimentally investigate the transient rheological behavior of concentrated xanthan gum solutions in start-up shear flow fields. Using a strain-controlled rheometer, a number of constant shear rates were suddenly imposed to aqueous xanthan gum solutions with different concentrations and the resultant shear stress responses were measured with time. The main findings obtained from this study can be summarized as follows: (1) For all shear rates imposed, however low it may be, the shear stress is rapidly increased with time (stress overshoot) upon inception of steady shear flow before passing through the maximum stress value and then gradually decreased with time (stress decay) until reaching a steady state flow. (2) As the imposed shear rate is increased, a more pronounced stress overshoot takes place and the maximum stress value becomes larger, whereas both times at which the maximum stress is observed and needed to reach a steady state flow are shortened. (3) The maximum shear stress is linearly increased with shear rate in a double logarithmic scale and becomes larger with increasing concentration at equal shear rates. In addition, the time at which the maximum stress occurs exhibits a linear relationship with the inverse of shear rate in a double logarithmic scale for all xanthan gum solutions, regardless of their concentrations. (4) The shear stress is sharply increased with an increase in strain until reaching the maximum stress at small range of deformations. The maximum stress is observed at similar strain values, irrespective of the imposed shear rates lower than 10 1/s. (5) The Bird-Leider model can be successfully used with regard to quantitatively predicting the transient behavior of concentrated xanthan gum solutions. However, this model has a fatal weakness in terms of describing a decrease in shear stress (stress decay).

The objective of the present study is to systematically evaluate and compare the rheological behaviors of body cream and body lotion in actual usage situations. Using a strain-controlled rheometer, the steady shear flow properties of commercially available body cream and body lotion were measured over a wide range of shear rates, and the linear viscoelastic properties of these two materials in small amplitude oscillatory shear flow fields were measured over a broad range of angular frequencies. The temperature dependency of the linear viscoelastic behaviors was additionally investigated over a temperature range most relevant to usual human life. The main findings obtained from this study are summarized as follows: (1) Body cream and body lotion exhibit a finite magnitude of yield stress. This feature is directly related to the primary (initial) skin feel that consumers usually experience during actual usage. (2) Body cream and body lotion exhibit a pronounced shear-thinning behavior. This feature is closely connected with the spreadability when cosmetics are applied onto the human skin. (3) The linear viscoelastic behaviors of body cream and body lotion are dominated by an elastic nature. These solid-like properties become a criterion to assess the selfstorage stability of cosmetic products. (4) A modified form of the Cox-Merz rule provides a good ability to predict the relationship between steady shear flow and dynamic viscoelastic properties for body cream and body lotion. (5) The storage modulus and loss modulus of body cream show a qualitatively similar tendency to gradually decrease with an increase in temperature. In the case of body lotion, with an increase in temperature, the storage modulus is progressively decreased while the loss modulus is slightly increased and then decreased. This information gives us a criterion to judge how the characteristics of cosmetic products are changed by the usual human environments.

The effect of a 60 Hz time-varying electric field was studied using a facing-electrode device (FED) and a coplanar-electrode device (CED) for further investigation of the genotoxicity of 60 Hz time-varying magnetic field (MF) from preceding research. Neither a single 30-minute exposure to the CED or to the FED had any obvious biological effects such as DNA double strand break (DSB) and apoptosis in cancerous SCC25, and HeLa cells, normal primary fibroblast IMR90 cells, while exposures of 60 Hz time-varying MF led to DNA damage with induced electric fields much smaller than those used in this experiment. Nor did repetitive exposures of three days or a continuous exposure of up to 144 hours with the CED induce any DNA damage or apoptosis in either HeLa or IMR90 cells. These results imply that the solitary electric field produced by time-varying MF is not a major cause of DSBs or apoptosis in cancer or normal cells.

The objective of this study is to systematically investigate the relationships between steady flow functions and transient flow functions for viscoelastic polymer liq- uids. Using a strain-controlled rheometer (Advanced Rheometric Expansion System (ARES)), the steady shear flow properties and the transient shear flow properties of concen- trated poly(ethylene oxide) (PEO) solutions have been measured over a wide range of shear rates and times. The validity of the three forms of the Gleissle mirror relations was examined by comparing them with the experimentally obtained results. In addition, the effect of nonlinearity on the applicability of these Gleissle mirror relations was discussed from a theoretical view-point by introducing the concept of a nonlinear strain measure. The main findings obtained from this study can be summarized as follows: (1) A nonlinear strain measure is decreased with an increase in strain magnitude, after reaching the maxi- mum value at small strain range. This behavior is quite different from the theoretical pre- diction to satisfy the conditions of the Gleissle mirror relations. (2) The first mirror relation describing the equivalence between steady shear flow viscosity and shear stress growth coefficient is valid over a wide range of shear rates and is hardly affected by the nonlinear- ity of polymer solutions. (3) The second mirror relation expressing the equivalence between first normal stress coefficient and first normal stress growth coefficient is also applicable over a wide range of shear rates. This relation is, however, significantly influ- enced by the degree of nonlinearity (i.e., shape of a nonlinear strain measure) of polymer solutions. (4) The third mirror relation can be regarded as a very useful empirical model to predict the first normal stress coefficient from steady shear flow viscosity data, provided that an appropriate value of a shift factor is given.