Preparation and Characterization of CA-MA Eutectic/Silicon Dioxide Nanoscale Composite Phase Change Material from Water Glass via Sol-Gel Method

This work mainly involved the preparation of a nano-scale form-stable phase change material（PCM） consisting of capric and myristic acid（CA-MA） binary eutectic acting as thermal absorbing material and nano silicon dioxide（nano-SiO_2） serving as the supporting material. Industrial water glass for preparation of the nano silicon dioxide matrix and CA-MA eutectic mixture were compounded by single-step sol-gel method with the silane coupling agent. The morphology, chemical characterization and form stability property of the composite PCM were investigated by transmission electron microscopy（TEM）, scanning electron microscopy（SEM）, Fourier-transform infrared（FT-IR） spectroscopy and polarizing microscopy（POM）. It was indicated that the average diameter of the composite PCM particle ranged from 30-100 nm. The CA-MA eutectic was immobilized in the network pores constructed by the Si-O bonds so that the composite PCM was allowed no liquid leakage above the melting temperature of the CA-MA eutectic. Differential scanning calorimetry（DSC） and thermogravimetric analysis（TGA） measurement were conducted to investigate the thermal properties and stability of the composite PCM. From the measurement results, the mass fraction of the CA-MA eutectic in the composite PCM was about 40%. The phase change temperature and latent heat of the composite were determined to be 21.15 ℃ and 55.67 J/g, respectively. Meanwhile, thermal conductivity of the composite was measured to be 0.208 W·m^（-1）·K^（-1） by using the transient hot-wire method. The composite PCM was able to maintain the surrounding temperature close to its phase change temperature and behaved well in thermalregulated performance which was verified by the heat storage-release experiment. This kind of form-stable PCM was supposed to complete thermal insulation even temperature regulation by the dual effect of relatively low thermal conductivity and phase change thermal storage-release properties. So it can be formulated that the nanoscale CA-MA/SiO_2 composite PCM with the form-stable property, good thermal storage capacity and relatively low thermal conductivity can be applied for energy conservation as a kind of thermal functional material.

Functional transition:Inconsistently parallel to the increase in future liver remnant volume after preoperative portal vein embolization

BACKGROUND Preoperative portal vein embolization(PVE)is a widely used strategy to enable major hepatectomy in patients with insufficient liver remnant.PVE induces hypertrophy of the future liver remnant(FLR)and a shift of the functional reserve to the FLR.However,whether the increase of the FLR volume(FLRV)corresponds to the functional transition after PVE remains unclear.AIM To investigate the sequential relationship between the increase in FLRV and functional transition after preoperative PVE using 3-dimensional(3D)computed tomography(CT)and 99mTc-galactosyl-human serum albumin(99mTc-GSA)singlephoton emission computed tomography(SPECT)fusion images.METHODS Thirty-three patients who underwent major hepatectomy following PVE at the Department of Gastroenterological Surgery I,Hokkaido University Hospital between October 2013 and March 2018 were enrolled.Three-phase dynamic multidetector CT and 99mTc-GSA SPECT scintigraphy were performed at pre-PVE,and at 1 and 2 wk after PVE;3D 99mTc-GSA SPECT CT-fused images were constructed from the Digital Imaging and Communications in Medicine data using 3D image analysis system.Functional FLRV(FFLRV)was defined as the total liver volume×(FLR volume counts/total liver volume counts)on the 3D 99m Tc-GSA SPECT CT-fused images.The calculated FFLRV was compared with FLRV.RESULTS FFLRV increased by a significantly larger extent than FLRV at 1 and 2 wk after PVE(P<0.01).The increase in FFLRV and FLRV was 55.1%±41.6%and 26.7%±17.8%(P<0.001),respectively,at 1 wk after PVE,and 64.2%±33.3%and 36.8%±18.9%(P<0.001),respectively,at 2 wk after PVE.In 3 of the 33 patients,FFLRV levels decreased below FLRV at 2 wk.One of the three patients showed rapidly progressive fatty changes in FLR.The biopsy at 4 wk after PVE showed macroand micro-vesicular steatosis of more than 40%,which improved to 10%.Radical resection was performed at 13 wk after PVE.The patient recovered uneventfully without any symptoms of pos-toperative liver failure.CONCLUSION The functional transition lagged behind the increase in FLRV after PVE in some cases.Evaluating both volume and function is needed to determine the optimal timing of hepatectomy after PVE.

Latent, sex-specific metabolic health effects in CD-1 mouse offspring exposed to PFOA or HFPO-DA (GenX) during gestation

Background:Perfluorooctanoic acid(PFOA)is an environmental contaminant associated with adverse metabolic outcomes in developmentally exposed human populations and mouse models.Hexafluoropropylene oxide-dimer acid(HFPO-DA,commonly called GenX)has replaced PFOA in many industrial applications in the U.S.and Europe and has been measured in global water systems from<1 to 9350 ng/L HFPO-DA.Health effects data for GenX are lacking.Objective:Determine the effects of gestational exposure to GenX on offspring weight gain trajectory,adult metabolic health,liver pathology and key adipose gene pathways in male and female CD-1 mice.Methods:Daily oral doses of GenX(0.2,1.0,2.0 mg/kg),PFOA(0.1,1.0 mg/kg),or vehicle control were administered to pregnant mice(gestation days 1.5-17.5).Offspring were fed a high-or low-fat diet(HFD or LFD)at weaning until necropsy at 6 or 18 weeks,and metabolic endpoints were measured over time.PFOA and GenX serum and urine concentrations,weight gain,serum lipid parameters,body mass composition,glucose tolerance,white adipose tissue gene expression,and liver histopathology were evaluated.Results:Prenatal exposure to GenX led to its accumulation in the serum and urine of 5-day old pups(P=0.007,P<0.001),which was undetectable by weaning.By 18 weeks of age,male mice fed LFD in the 2.0 mg/kg GenX group displayed increased weight gain(P<0.05),fat mass(P=0.016),hepatocellular microvesicular fatty change(P=0.015),and insulin sensitivity(P=0.014)in comparison to control males fed LFD.Female mice fed HFD had a significant increase in hepatocyte single cell necrosis in 1.0 mg/kg GenX group(P=0.022)and 1.0 mg/kg PFOA group(P=0.003)compared to control HFD females.Both sexes were affected by gestational GenX exposure;however,the observed phenotype varied between sex with males displaying more characteristics of metabolic disease and females exhibiting liver damage in response to the gestational exposure.Conclusions:Prenatal exposure to 1 mg/kg GenX and 1 mg/kg PFOA induces adverse metabolic outcomes in adult mice that are diet-and sex-dependent.GenX also accumulated in pup serum,suggesting that placental and potentially lactational transfer are important exposure routes for GenX.