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Non-alcoholic fatty liver disease (NAFLD) covers a spectrum of disease ranging from simple steatosis (NAFL) to non-alcoholic steatohepatitis (NASH) and fibrosis. “Obese/Metabolic NAFLD” is closely associated with obesity and insulin resistance and therefore predisposes to type 2 diabetes and cardiovascular disease. NAFLD can also be caused by common genetic variants, the patatin-like phospholipase domain-containing 3 (PNPLA3) or the transmembrane 6 superfamily member 2 (TM6SF2). Since NAFL, irrespective of its cause, can progress to NASH and liver fibrosis, its definition is of interest. We reviewed the literature to identify data on definition of normal liver fat using liver histology and different imaging tools, and analyzed whether NAFLD caused by the gene variants is associated with insulin resistance. Histologically, normal liver fat content in liver biopsies is most commonly defined as macroscopic steatosis in less than 5% of hepatocytes. In the population-based Dallas Heart Study, the upper 95th percentile of liver fat measured by proton magnetic spectroscopy (1H-MRS) in healthy subjects was 5.6%, which corresponds to approximately 15% histological liver fat. When measured by magnetic resonance imaging (MRI)-based techniques such as the proton density fat fraction (PDFF), 5% macroscopic steatosis corresponds to a PDFF of 6% to 6.4%. In contrast to “Obese/metabolic NAFLD”, NAFLD caused by genetic variants is not associated with insulin resistance. This implies that NAFLD is heterogeneous and that “Obese/Metabolic NAFLD” but not NAFLD due to the PNPLA3 or TM6SF2 genetic variants predisposes to type 2 diabetes and cardiovascular disease.  相似文献   

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Theoretical Foundations of Chemical Engineering - This work includes a 3D computational fluid dynamics study on rectangular-shaped micromixers. Initially, T-shaped micromixer types are considered...  相似文献   

4.
It has been reported that the main factors which influence the properties of self-flow castable are:1) the particle size distribution and 2) the function of dispersant and surfactant ,In the present paper,the optimum range of particle size distribution and the best ispersant and surfactant as well as the function mechanisms are discussed,Also a method to eveluate self-flow castable are given.  相似文献   

5.
This work studied the characteristics of SiO2 distribution and structure of silicate phases in MgO-ZrO2 composites synthesizedby raw materials of light fired magnesite nd zircon,The results indicate that 30 wt%-40wt% SiO2 content in the system is existed in the form of crystalline of forsterite (M2S),the remaindering of SiO content (60wt%0-70wt%) is existed in the glass phase,The chemical composition of glass phase is well agreed with the chemical composition of monticellite(CMS).  相似文献   

6.
Dielectric measurements are reported on epoxy bonded aluminium joints exposed to moisture at 75°C. The observed changes in the dielectric spectrum that occur with time of exposure are correlated with the variation in the mechanical strength. Certain joints were subjected to periodic cooling to ?20°C to simulate the shock of aircraft flight. The effects of dehydration were examined for joints that had been exposed to moisture for a prolonged period of time. The data indicate that the initial hydration process lowers the glass transition temperature and the stress released creates micro-voids. Further ageing leads to hydroxide formation in the interfacial layer. Freezing of water during the thermal spike experiments induces cracking in the adhesive, and leads to greater water uptake. Plasticisation of the resin appears to be to a large extent reversible and dehydration allows some recovery of the bond strength. The shock cooling of the joints has only a relatively small effect on the ageing of the joints but does, however, produce differences in the dielectric data. This study illustrates the power of the dielectric technique for the assessment of ageing in adhesively bonded structures.  相似文献   

7.
The interrelation of various factors affecting the mechanical strength ,the thermal shock resistivity and creep deformation of slab in a simple setting condition of the firing of table ware are discussed,The conrol of parameters in favour of the desired performance of the slab is propsed.  相似文献   

8.
In order to reduce the maximum peel and shear stress concentrations in the adhesive layer, a smart adhesively bonded scarf joint system was developed by surface bonding of piezoelectric patches onto a typical scarf joint. The forces and bending moments at the edges of the developed smart joint system can be adaptively controlled by adjusting the applied electric field on the piezoelectric patches, thus reducing the peel and shear stresses concentration in the adhesive layer. In order to verify the effect of surface bonding of piezoelectric patches in smart scarf adhesive joints, an analytical model was developed to evaluate the shear stress distribution and to predict the peel stress. It was established that the piezoelectric patched joint could reduce the stress concentrations at the scarf joint edges. The influence of the electric field and the effects of the scarf angle and the adherend Young's modulus on the peel and shear stresses were investigated. It was found that the effect of scarf angle is more significant at higher angles to raise the stresses. The effect of the electric field on the shear stress is more significant than on the peel stress.  相似文献   

9.
Zn–Mn electrodeposition onto Pt from an electrolyte containing boric–sorbitol complex (BSC) or boric acid alone (BA) was studied. The influence of BA or BSC content on the deposition process was investigated by cyclic voltammetry and electrodeposits, produced potentiostatically, were analysed by SEM, EDX, and XRD. The voltammetric studies indicated that an increase in the BSC concentration led to a decrease in the deposition current density. EDX analysis of deposits obtained at −1.60 V showed that increasing the BA or BSC concentration in the bath induced a fall in the Mn content of the electrodeposit and that for BSC this decrease was more significant. SEM images showed that the Zn–Mn electrodeposit obtained in the presence of 0.24 M BSC were smoother than other deposits; hence, BSC acted as a grain refiner at this concentration. XRD analysis of this deposit indicated that it was composed of Zn, Mn, MnZn13, and MnH0.8.  相似文献   

10.
The effects of process variables on the microcellular structure and crystallization of foamed polypropylene (PP) with supercritical CO2 as the foaming agent were investigated in this article. The cell size increased and the cell density reduced with increased foaming temperature. Differently, both the cell diameter and cell density increased as saturation pressure increased. DSC curves showed that the melting peak was broadened when supercritical CO2 foaming PP. Furthermore, the width at half-height of the melting peak increased, the melting peak moved to higher temperature, and the melting point and crystallinity enhanced as the foaming temperature lowered and the saturation pressure enhanced.  相似文献   

11.
The anti-oxidation agents containing Al2O3-MgO-C refractories was developed and the properties of them were investigated after being tratd at different temperature.It was found that the anti-oxidation agents could enhance the anti-oxidation property and increase the mechanic property of the refractories,The mineral components of the oxidation film were detected with XRD method.  相似文献   

12.
Results of a study of the interaction and parameters of the fine structure in the titanium carbide – diamond – nickel – molybdenum system near the titanium carbide – carbon (diamond) eutectic are presented after the action of a pressure of 5.7 GPa and a temperature of 1820 – 2300 K on the original powders. It is shown that molybdenum in a free state is virtually absent in the system. Its major part seems to dissolve in nickel. As a result of the action of high pressure and subsequent cooling in a high-pressure chamber, titanium carbide and nickel are shown to undergo high plastic deformations. In the opinion of the authors, the interaction that occurs in the system should cause a considerable strain hardening of the material and improvement of its mechanical properties.  相似文献   

13.
Two oligomers, each containing 3 l-lysine residues, were used as model molecules for the simulation of the β-sheet conformation of ɛ-polylysine (ɛ-PLL) chains. Their C terminals were capped with ethylamine and N terminals were capped with α-l-aminobutanoic acid, respectively. The calculations were carried out with the hybrid two-level ONOIM (B3LYP/6-31G:PM3) computational chemistry method. The optimized conformation was obtained and IR frequencies were compared with experimental data. The result indicated that the two chains were winded around each other to form a distinct cyclohepta structure through bifurcated hydrogen bonds. The groups of amide and α-amidocyanogen coming from one chain and the carbonyl group from the other chain were involved in the cyclohepta structure. The bond angle of the bifurcated hydrogen bonds was 66.6°. The frequency analysis at ONIOM [B3LYP/6-31G (d):PM3] level showed the IR absorbances of the main groups, such as the amide and amidocyanogen groups, were in accordance with the experimental data.  相似文献   

14.
Magnesium hydroxide [Mg(OH)2] is one of the potential inorganic fillers. In this work, nanoparticles (37±5 nm) of the magnesium hydroxide were prepared using matrix-mediated growth and control technique, and their size was confirmed by X-ray diffraction technique. Nano-Mg(OH)2-SBR and nano-Mg(OH)2-PBR composites with 2–10% (w/w) filler loading were prepared by compounding on laboratory-scale two-roll mill and a compression molding machine. These composites were tested for tensile and physical properties, and the properties were compared with the composites of commercial Mg(OH)2. The incorporation of nanofiller improved the properties of nanocomposites.  相似文献   

15.
The causes of the deactivation of catalysts for fuel combustion MeCr2O4/ -Al2O3 (Me = Cu or Mg) have been investigated using a variety of complex physical-chemical methods: IRS, ESDR, XPS, TPD and a pulse microcatalytic method. It has been concluded that the observed deactivation of catalysts during fuel combustion is due to the combined effect of high temperatures and reduction media.  相似文献   

16.
The influence of the composition of AOD slag on the corrosion of rebonded magnesite-chrome brick has been studied by analyzing the residual bricks at the tuyere zone of AOD .It indicates that the corrosion degree increased with the increase of the basicity of slag and decreased with the increase of the content of MgO ,Cr2O3 and Al2O3 in slag.And the addition of refractories to slag up to satura-tion could decrease the corrosion abiliy of sag.It is important to make a resonable slagmaking rule and ensure the percentage of MgO in slag more than 11wt% for pro-longing the service life of lining.  相似文献   

17.
1IntroductionAdditive agent plays a great role in changingphysical and chemical properties and microstructure ofmaterials,especially in CaO-riched MgO-CaO refracto-ry system.Rare earth elements[1~6]have high electronlevel and special electronic structure …  相似文献   

18.
《分离科学与技术》2012,47(5):817-832
ABSTRACT

In this study a comparative biosorption of iron(III)—cyanide complex anions from aqueous solutions to Rhizopus arrhizus and Chlorella vulgaris was investigated. The iron(III)—cyanide complex ion-binding capacities of the biosorbents were shown as a function of initial pH, initial iron(III)—cyanide complex ion, and biosorbent concentrations. The results indicated that a significant reduction of iron(III)—cyanide complex ions was achieved at pH 13, a highly alkaline condition for both the biosorbents. The maximum loading capacities of the biosorbents were found to be 612.2 mg/g for R. arrhizus at 1996.2 mg/L initial iron(III)—cyanide complex ion concentration and 387.0 mg/g for C. vulgaris at 845.4 mg/L initial iron(III)—cyanide complex ion concentration at this pH. The Freundlich, Langmuir, and Redlich-Peterson adsorption models were fitted to the equilibrium data at pH 3, 7, and 13. The equilibrium data of the biosorbents could be best fitted by all the adsorption models over the entire concentration range at pH 13.  相似文献   

19.
Approaches based on Taguchi and analysis of variance (ANOVA) methods have been proposed for studying the leaching of copper–cobalt flotation tailings. Taguchi method was used to determine the optimum leaching conditions as well the most influential operating parameters. ANOVA was used to determine the relationship between the experimental conditions and yield levels, as well as to define the significances of parameters on the leaching yields. An L25(55) orthogonal array experimental plan was used to assess the effects of initial acidity (25, 50 , 75, 100, and 125?g/L), leaching time (30, 60, 90, 120, and 150?min), temperature (25, 35, 45, 55, and 65°C), pulp density (S/L?=?10, 15, 20, 25, and 30 solid percent), and ferrous iron concentration (0.0, 1.0, 2.5, 5.0, and 7.5?g/L) on individual dissolution of Cu and Co. Under the optimum conditions (50?g/L, 60?min, 45°C, 15%, 2.5?g/L for Cu; and 100?g/L, 60?min, 65°C, 15% and 2.5?g/L for Co), leaching yields were 95.98% Cu and 97.74% Co. pH and Fe2+ were found to be key influential parameters of Cu and Co, respectively.  相似文献   

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