An Active and Soft Hydrogel Actuator to Stimulate Live Cell Clusters by Self-folding

The hydrogels are widely used in various applications, and their successful uses depend on controlling the mechanical properties. In this study, we present an advanced strategy to develop hydrogel actuator designed to stimulate live cell clusters by self-folding. The hydrogel actuator consisting of two layers with different expansion ratios were fabricated to have various curvatures in self-folding. The expansion ratio of the hydrogel tuned with the molecular weight and concentration of gel-forming polymers, and temperature-sensitive molecules in a controlled manner. As a result, the hydrogel actuator could stimulate live cell clusters by compression and tension repeatedly, in response to temperature. The cell clusters were compressed in the 0.7-fold decreases of the radius of curvature with 1.0 mm in room temperature, as compared to that of 1.4 mm in 37 degrees C. Interestingly, the vascular endothelial growth factor (VEGF) and insulin-like growth factor-binding protein-2 (IGFBP-2) in MCF-7 tumor cells exposed by mechanical stimulation was expressed more than in those without stimulation. Overall, this new strategy to prepare the active and soft hydrogel actuator would be actively used in tissue engineering, drug delivery, and micro-scale actuators

Ixeris dentata (Thunb) Nakai attenuates cognitive impairment in MPTP-treated mouse model of Parkinson's disease

Purpose: To evaluate the cognition-enhancing effect of Ixeris dentata (Thunb) Nakai in a mouse model of Parkinson's disease (PD). Methods: MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-induced mouse model of PD was used to evaluate the effect of Ixeris dentata (IDE) extract on the alteration of behavioral responses using rotarod and passive avoidance tests. The effect of IDE on oxidative stress levels were analyzed based on superoxide dismutase (SOD) and catalase (CAT) enzyme levels, and lipid peroxidation (LPO) in brain tissues. Results: MPTP (20 mg/kg, ip)-induced mice resulted in a significant (p < 0.01) behavioral deficiencies in locomotor behavior (from 53.15 ± 1.01 to 23.56 ± 1.04) and cognitive functions (from 297 ± 2.47 to 201.17 ± 3.23 s) compared with their respective control groups. Administration of IDE (20, 40 and 80 mg/kg, po) for three weeks significantly and dose-dependently improved (p < 0.001 at 80 mg/kg) locomotor and cognitive deficits in MPTP- treated mice. IDE treatment also significantly (p < 0.01 at 80 mg/kg) inhibited decrease in superoxide dismutase and catalase enzyme activities, and lipid peroxides in MPTP-treated mice in brain tissues. Conclusion: IDE exhibits good protection against MPTP-induced behavioral deficits via potential antioxidant defense mechanisms. Therefore, IDE could potentially be developed as a therapeutic approach for the treatment of neurodegenerative diseases. Keywords: Ixeris dentata, Neurodegenerative disease, MPTP, Parkinson's disease, Oxidative stres

Anti-oxidative and anti-neuroinflammatory effects of ethyl acetate extract fractions of Suaeda asparagoides MIq

Purpose: To evaluate the in vitro antioxidant and anti-neuroinflammatory effects of Suaeda asparagoides ethylacetate extract (SAE) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells.Methods: The antioxidative activity of SAE was evaluated by measuring 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity  spectrometrometrically. Cell viability was evaluated by 3-(4, 5- dimethylthiazol-2-yl)-2, 5- diphenyl-tetrazolium bromide (MTT) assay, while LPS-stimulated BV-2 microglia were used to study the expression and production of inflammatory mediators, including nitric oxide (NO), inducible NO synthase (iNOS) and tumor necrosis alpha (TNF-α).Results: Pretreatment with SAE prior to LPS treatment significantly inhibited excessive production of NO (p < 0.001 at 20, 40, 80 and 100 μg/mL) in a dose-dependent manner, and was associated with down-regulation of expression of inducible nitric oxide synthase (iNOS). SAE also suppressed the LPSinduced increase in TNF-α level (p < 0.01at concentrations of 40 and 80 μg/mL) in BV-2 cells. Furthermore, DPPH-generated free radicals were inhibited by SAE in a concentration-dependent manner.Conclusion: These results indicate that SAE possesses strong anti-oxidant properties, and inhibits excessive production of pro-inflammatory mediators, including NO, iNOS and TNF-α, in LPS-stimulated BV-2 cellsKeywords: Suaeda asparagoides, DPPH, Anti-inflammatory activity, Microglial cells, iNOS, TNF-

Prediction of severe accident occurrence time using support vector machines

AbstractIf a transient occurs in a nuclear power plant (NPP), operators will try to protect the NPP by estimating the kind of abnormality and mitigating it based on recommended procedures. Similarly, operators take actions based on severe accident management guidelines when there is the possibility of a severe accident occurrence in an NPP. In any such situation, information about the occurrence time of severe accident-related events can be very important to operators to set up severe accident management strategies. Therefore, support systems that can quickly provide this kind of information will be very useful when operators try to manage severe accidents. In this research, the occurrence times of several events that could happen during a severe accident were predicted using support vector machines with short time variations of plant status variables inputs. For the preliminary step, the break location and size of a loss of coolant accident (LOCA) were identified. Training and testing data sets were obtained using the MAAP5 code. The results show that the proposed algorithm can correctly classify the break location of the LOCA and can estimate the break size of the LOCA very accurately. In addition, the occurrence times of severe accident major events were predicted under various severe accident paths, with reasonable error. With these results, it is expected that it will be possible to apply the proposed algorithm to real NPPs because the algorithm uses only the early phase data after the reactor SCRAM, which can be obtained accurately for accident simulations

The Evaluation of CP-001 (a Standardized Herbal Mixture of Houttuynia cordata

In the present study, the effect of CP-001, a standardized herbal mixture of Houttuynia cordata, Rehmannia glutinosa, Betula platyphylla, and Rubus coreanus, on cytochrome P450 (CYP) enzyme-mediated drug metabolism was investigated in vitro to evaluate the potential for herb-drug interactions. CP-001 was tested at concentrations of 1, 3, 10, 30, and 100 μg/mL. A CYP-specific substrate mixture was incubated with CP-001 in human liver microsomes, and the metabolites generated by each CYP-specific metabolic reaction were measured by liquid chromatography-tandem mass spectrometry. CP-001 seemed to slightly inhibit some CYP isozymes, but the IC50 values for all CYP isozymes were greater than 100 μg/mL. Furthermore, CP-001 did not exhibit time-dependent CYP inhibitory activities, indicating that it does not act as a mechanism-based inactivator of CYP enzymes. In conclusion, the effects of CP-001 on CYP isozyme activities were negligible at the concentrations tested. Therefore, the likelihood of herbal mixture-drug interaction is considered minimal