Application of nanoparticles-assembled bi-porous structures to power electronics cooling

Nanoparticles-assembled bi-porous structure is newly proposed and its potential to enhance the boiling heat transfer is evaluated in order to develop a new cooling device toward 300W/cm2 of on-vehicle inverter cooling. In order to assemble nanoparticles on to a heat transfer surface as a thin layer, a boiling adhesion method (BAM) is originally introduced in which, water or water/ethanol solution with mono-dispersed nanoparticles is dropped or sprayed onto a high temperature surface, and then the nanoparticles deposit onto the heat transfer surface during the boiling. In addition to that, it is expected that boiling bubbles can produce micro or milli scale of pores at the same time. In order to evaluate the applicability of the nanoparticles-assembled bi-porous structures, droplet behavior on a high temperature surface is visualized with a high speed camera The experimental results show that the boiling adhesion method can produce multi-scale pore structures composed of nano-scale pores and micro-scale pores and that the water droplet intensely boils and evaporates on a high temperature of a wall with nanoparticles-assembled bi-porous layer even under Leidenfrost conditions, which proves that the nanoparticles-assembled bi-porous structure enables the increase in both the critical heat flux and the boiling heat transfer in a nucleate boiling regim

Neural bases of the adaptive mechanisms associated with reciprocal partner choice

AbstractIn our society, partner choice is often reciprocal and, therefore, compromising one's choice may be adaptive depending on one's own market price. To reveal the neural mechanisms underlying this adaptive process, functional magnetic resonance imaging (fMRI) was performed on 27 male subjects during virtual partner choice tasks involving a dance-partner choice or a part-time job choice. Following the evaluation of a rival, the subjects chose a partner either in the face of competition with a rival (reciprocal choice condition) or during no competition (nonreciprocal condition). Irrespective of the type of partner choice situation, the posterior cingulate cortex (PCC) and right temporoparietal junction (TPJ) were specifically activated during reciprocal partner choice. The PCC was also activated during the evaluation of a rival relative to the self, which indicates the involvement of this region in the processing of one's own market price. Activation in the right TPJ was related to the individual tendency to avoid choosing a higher-value candidate when the rival-value was high in the reciprocal choice condition, which indicates that this region plays a role in market-adaptive strategy. Taken together with extant anatomical knowledge, the two-component neurobiological structure underlying the adaptive mechanism of partner choice identified in this study seems to represent the hierarchical evolution of the human socio-cognitive system

Daily intake of β-cryptoxanthin prevents bone loss by preferential disturbance of osteoclastic activation in ovariectomized mice

AbstractAlthough β-cryptoxanthin, a xanthophyll carotenoid, has been shown to exert an anabolic effect on bone calcification, little attention has been paid thus far to the precise mechanism of bone remodeling. Daily oral administration of β-cryptoxanthin significantly inhibited osteoclastic activation as well as reduction of bone volume in ovariectomized mice. In vitro studies revealed that β-cryptoxanthin inhibited differentiation and maturation of osteoclasts by repression of the nuclear factor-κB-dependent transcriptional pathway. Our results suggest that supplementation with β-cryptoxanthin would be beneficial for prophylaxis and for therapy of metabolic bone diseases associated with abnormal osteoclast activation

Biological performance of novel phosphate-based glass microspheres for mesenchymal stem cell therapy in osteoporotic patients

In this study, degradable phosphate-based bulk or porous glass microspheres (BGMS or PGMS), with nominal molar compositions of P45-(45P2O5-16CaO-24MgO-11Na2O-4Fe2O3) and P40-(40P2O5-16CaO-24MgO-20Na2O), were evaluated for cytotoxicity, cytocompatibility and osteogenic potential for Mesenchymal stem cell (MSC)-based therapy in osteoporotic patients. Evaluations were performed using direct-contact and indirect-contact bone marrow derived human MSC (hMSC)-based experiments, in addition to material characterisations such as morphology, elemental composition and degradation behaviour, which were correlated to the hMSC experiments. Degradation of microspheres (MS) was measured using a novel method where Scanning Electron micrographs was used to assess the number of MS with surface damage (cracks and peeling effect), over 42 days of degradation in culture medium. Results showed that after 42 days, 2%, 46% and 29% of P45 BGMS, P40 BGMS and P40 PGMS, respectively, had cracks or peeling off surfaces. The results for direct-contact hMSC-experiments showed that P45 BGMS supported 1.4 times more hMSCs than P40 BGMS over 31 days of culture period. However, P45 BGMS were not osteoinductive, possibly due to hydrophobic nature of this glass and its slower dissolution rate. On the other hand, in comparison to P45 BGMS, hMSCs seeded on P40 BGMS showed up to 1.7 times higher alkaline phosphatase (ALP) activity on Day 7, up to 1.5 times more collagen and at least 6 times more Ca deposited in extracellular matrix, in addition to osteocalcin on Day 21 of culture, which strongly indicated the osteoinductive nature of P40 BGMS. This effect was also confirmed through indirect-contact experiments where there was higher collagen and Ca production by hMSCs was observed after 25 days of culture in P40 BGMS-conditioned medium as compared to control (no MS) or P45-conditioned medium. Elemental analysis using Energy Dispersive X-Ray Spectroscopic (EDS) analysis revealed that the Ca-based porogen used in the manufacturing of PGMS, may have been retained on the edges of the pores in PGMS. Therefore, an acid-washing step was introduced at the end of manufacturing process in order to remove the porogen and limit the possible cytotoxic effect of porogen and excess calcium. Characterisation results indicated that acid washing changed the physicality of these microspheres without changing their chemical composition. For example, mean and mode pore window sizes on the surface of PGMS increased from 2.63 μm to 2.73 μm and from 1.15 μm to 1.53 μm, respectively, and closed porosity decreased by 27%, as a result of acid washing. However, more detailed EDS analysis revealed that the Ca-based porogen was not being completely removed from PGMS even after acid washing and this may need further investigation. Cytotoxicity evaluations over 7 days of elution (indirect-contact hMSC experiments) suggested that there was marked improvement in hMSC membrane integrity and metabolic activity in PGMS neat extracts after acid washing. Moreover, direct-contact hMSC experiments also showed higher DNA content on acid washed (AW) P40 PGMS over 7 days of culture. Therefore, based on these results, it was hypothesised that acid washing may have opened up some of the pores and removed some of the glass fragments from PGMS surface, which may have been responsible for cytotoxicity in non-AW PGMS. Direct-contact experiments also showed that over 42-day culture period, there was up to 1.6 times higher hMSC numbers in AW P40 PGMS as compared to P40 BGMS. However, this increase was much lower than the expected range as there was more than 10-fold increase in surface area after the introduction of porosity. This was probably due to presence of <5 μm and <10 μm pore window sizes and interconnection sizes, respectively, in these microspheres, which allowed limited penetration of hMSCs into the porous structures. There was also evidence of at least 2 times more ALP activity up to day 42 of culture and up to 1.7 times more collagen production by day 21 of culture, in case of AW P40 PGMS as compared to P40 BGMS, which strongly indicated a positive effect of porosity on osteogenesis. Interestingly, there was also lower Ca and P deposited by hMSCs in porous microspheres, which was in line with the observations made through indirect-contact experiments, where there was lower collagen and Ca production by hMSCs in P40 PGMS-conditioned medium as compared to P40 BGMS-conditioned medium. This negative effect of PGMS was hypothesised due to excess release of glass fragments/particulates and calcium ions into the medium, possibly leading to cytotoxicity. Based on the results shown here, there is a potential of P40 BGMS and AW P40 PGMS for hMSC-based bone repair therapy. However, future work needs to be done in order to limit the delamination of glass surfaces and release of glass fragments/particulates from these MS, as a result of degradation

Abnormal phospholipids distribution in the prefrontal cortex from a patient with schizophrenia revealed by matrix-assisted laser desorption/ionization imaging mass spectrometry

Schizophrenia is one of the major psychiatric disorders, and lipids have focused on the important roles in this disorder. In fact, lipids related to various functions in the brain. Previous studies have indicated that phospholipids, particularly ones containing polyunsaturated fatty acyl residues, are deficient in postmortem brains from patients with schizophrenia. However, due to the difficulties in handling human postmortem brains, particularly the large size and complex structures of the human brain, there is little agreement regarding the qualitative and quantitative abnormalities of phospholipids in brains from patients with schizophrenia, particularly if corresponding brain regions are not used. In this study, to overcome these problems, we employed matrix-assisted laser desorption/ionization imaging mass spectrometry (IMS), enabling direct microregion analysis of phospholipids in the postmortem brain of a patient with schizophrenia via brain sections prepared on glass slides. With integration of traditional histochemical examination, we could analyze regions of interest in the brain at the micrometric level. We found abnormal phospholipid distributions within internal brain structures, namely, the frontal cortex and occipital cortex. IMS revealed abnormal distributions of phosphatidylcholine molecular species particularly in the cortical layer of frontal cortex region. In addition, the combined use of liquid chromatography/electrospray ionization tandem mass spectrometry strengthened the capability for identification of numerous lipid molecular species. Our results are expected to further elucidate various metabolic processes in the neural system

Serum Autotaxin Is a Useful Disease Progression Marker in Patients with Primary Biliary Cholangitis

Autotaxin (ATX) is a secreted enzyme metabolized by liver sinusoidal endothelial cells that has been associated with liver fibrosis. We evaluated serum ATX values in 128 treatment-naive, histologically assessed primary biliary cholangitis (PBC) patients and 80 healthy controls for comparisons of clinical parameters in a case-control study. The median ATX concentrations in controls and PBC patients of Nakanuma's stage I, II, III, and IV were 0.70, 0.80, 0.87, 1.03, and 1.70 mg/L, respectively, which increased significantly with disease stage (r = 0.53, P < 0.0001) as confirmed by Scheuer's classification (r = 0.43, P < 0.0001). ATX correlated with Wisteria floribunda agglutinin-positive Mac-2 binding protein (M2BPGi) (r = 0.51, P < 0.0001) and fibrosis index based on four factors (FIB-4) index (r = 0.51, P < 0.0001). While ALP and M2BPGi levels had decreased significantly (both P < 0.001) by 12 months of ursodeoxycholic acid treatment, ATX had not (0.95 to 0.96 mg/L) (P = 0.07). We observed in a longitudinal study that ATX increased significantly (P < 0.00001) over 18 years in an independent group of 29 patients. Patients succumbing to disease-related death showed a significantly higher ATX increase rate (0.05 mg/L/year) than did survivors (0.02 mg/L/year) (P < 0.01). ATX therefore appears useful for assessing disease stage and prognosis in PBC.ArticleSCIENTIFIC REPORTS.8:8159(2018)journal articl