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The method of high temperature physical vapor transport (HTPVT) is an available approach to prepare silicon carbide (SiC) ceramics with high density and high purity. In the present work, α-SiC (6H-SiC) and β-SiC (3C-SiC) powders were used as starting materials respectively to fabricate SiC ceramics with HTPVT process, and the effects of starting materials on nucleation, density, microstructure and mechanical properties of SiC ceramics were investigated. It showed that at high temperature, the decomposition rate of β-SiC was higher than that of α-SiC, and at the initial nucleation stage, the average grain size of SiC crystal obtained with β-SiC starting materials was smaller than that with α-SiC starting materials, because higher vapour pressure of gas phase which decomposed by β-SiC starting materials facilitated nucleation and growth of SiC grains. Density of the resulted SiC ceramics using α-SiC and β-SiC as starting materials was 3.16 g·cm-3 and 3.17 g·cm-3, indicating close values, while, using β-SiC as the starting materials, the grain size was smaller, consequently, the flexure strength was higher. Increasing growth temperature from 2200°C to 2300°C, the densities and the flexure strength of the SiC ceramics using either α-SiC or β-SiC were decreased.

Background Aconiti Lateralis Radix Praeparata has been used as the first cardiac drug over a 1000 years in Asian countries. Although most detoxification products are confirmed to be safe, the effect is not potent as desired. In previous study, we designed a one-step detoxification product by fresh cutting and continuously dried, which preserved more water-soluble alkaloids while eliminating toxicity. It is thus necessary to find more in vivo evidence to support its industrial development. Methods Initially, network pharmacology was applied to analyze the related pathways of candidate components acting on heart failure diseases. Then, two heart failure models that were induced by propafenone hydrochloride and nimodipine (v/v, 1:1) and were given doxorubicin were carried out to test the cardiac activity. Moreover, the effect on mitochondrial energy metabolism was further assessed. Results Network pharmacology results indicated that Aconiti Lateralis Radix Praeparata treated heart failure through cAMP signaling pathway, calcium signaling pathway, adrenergic signaling in cardiomyocytes and so on. These pathways were highly correlated with myocardial contractility and mitochondrial energy metabolism. Trials on heart failure rats demonstrated that the novel processed-product could produce a stronger positive inotropic action and increase more Na+–K+–ATPase and Ca2+–Mg2+–ATPase than Heishunpian. Pathological results also revealed the novel one could better restore the morphology of cardiomyocytes and reduce vacuolar lesions. It also could inspire more energy with a lower concentration. Conclusions This study provides scientific evidence for the clinical application of new products. It is of great benefit to innovate the industrial detoxification process of Aconitum. Electronic supplementary material The online version of this article (10.1186/s13020-018-0219-4) contains supplementary material, which is available to authorized users.

In this paper, clay bonded silicon carbide was prepared through pressureless sintering process with silicon carbide dusting powder as raw materials and clay as sintering additive. The effects of the ball-milling method, sintering temperature and clay contents on the density, microstructure and mechanical properties of clay bonded silicon carbide refractory were studied. The planetary ball-milling was a good method to improve the density of the green body, and the density was increased simultaneously with an increase of the clay content. The liquid phase derived from low-melting eutectic mixtures of clay could prevent the superlative oxidation of silicon carbide. The mass increment of sintered samples decreased firstly and then increased at the sintering temperature range from 1250 to 1500 °C. The open porosity of samples decreased with the clay addition at a content range from 10 to 30 wt.%. The bending strength of the samples decreased firstly and then increased with the clay addition increasing. The optimum condition for preparing clay bonded silicon carbide with silicon carbide dusting powder was sintering at 1350 °C with 20 wt.% clay, and the obtained sample with a porosity of 24% achieved the bending strength of 78±7 MPa.

In this paper, reaction bonded silicon carbide (RBSC) was prepared by silicon infiltration with silicon carbide and carbon black as raw materials. The effects of the mixing methods with different binders on density of green body were compared. The influences of phenolic resin content, forming pressure, sintering temperature of samples on the performance of green body, mechanical microstructure and properties of RBSC were studied. The result shows that the density of green body by wet-mixing with alcohol-soluble binder (phenolic resin) was much better than semi-dry-mixing with usual water-soluble binders (polyvinyl alcohol and carboxy methyl cellulose sodium). The bending strength of green body prepared with phenolic resin at the content of 12 wt.% reached to the maximum value. The density of RBSC increased generally with phenolic resin content increasing at temperature range from 1550 to 1650 °C. The bending strength of RBSC increased firstly and then decreased with phenolic resin content increasing at a sintering temperature of 1600 °C. The optimum condition for fabricating RBSC was sintering at 1600 °C with 12 wt.% phenolic resin, the density, porosity and bending strength of the obtained RBSC was 3.06 g·cm-3, 0.05% and 370±54 MPa, respectively.

Three diamine monomers (ethylenediamine, butylenediamine, and p-phenylenediamine) were selected for cross-linking graphene oxide (GO) to prepare composite graphene oxide-framework (GOF) membranes through filtration using a pressure-assisted self-assembly technique. The membranes were applied to separate an ethanol–water mixture by pervaporation. Unmodified GO comprised only hydrogen bonds and π–π interactions, but after cross-linking it with a diamine, attenuated total reflectance–Fourier transform infrared and X-ray photoelectron spectroscopy demonstrated that the diamine was chemically bonded both to GO and the membrane support. Moreover, GO hydrophilicity was substantially altered; water contact angle increased from 24.4° to 80.6° (from cross-linking with an aliphatic structure of diamine to cross-linking with an aromatic structure). Results of X-ray diffraction showed that d-spacing in GOF layers varied from 10.4 to 8.7 A. For GOFs presoaked in 90 wt % ethanol–water, covalent bonds between the layer a...

Ethnopharmacological relevance Pinelliae Rhizoma (PR), the dried tuber of Pinellia ternata (Thunb.) Breit., is a traditional Chinese medicinal herb. It is commonly used for treating cancer, cough and phlegm. To treat cancer, Chinese medicine practitioners often use raw PR; while to treat cough and phlegm, they usually use Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine (PRZA, raw PR processed with ginger juice and alumen as adjuvant materials). Currently, the producing protocol of PRZA varies greatly among different places in China. This study aims to standardize the manufacturing procedure for PRZA. We also evaluated the impact of processing on the bioactivities and chemical profile of raw PR. Materials and methods We used the orthogonal design to optimize the manufacturing procedure of PRZA at bench scale, and validated the optimized procedure in pilot-scale production. The MTT assay was used to compare the cytotoxicities of raw PR and PRZA in hepatocellular carcinoma HepG2 cells. Animal models (ammonia liquor-induced cough model and phenol red secretion model) were used to compare the antitussive and expectorant effects of raw PR and PRZA, respectively. The chemical profiles of raw PR and PRZA samples were compared using a newly developed ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) method. Results The standardized manufacturing procedure for PRZA is as follows: soak raw PR in water until the center of the cut surface is devoid of a dry core, after that, boil the herb in water (for each 100 kg raw PR, 12.5 kg alumen and 25 L freshly squeezed ginger juice are added) for 6 h, and then take out and dry them. The cytotoxicity of PRZA was less potent than that of raw PR. Intragastric administration of raw PR or PRZA demonstrated antitussive and expectorant effects in mice. These effects of PRZA were more potent than that of raw PR at the dose of 3 g/kg. By comparing the chemical profiles, we found that six peaks were lower, while nine other peaks were higher in PRZA than in raw PR. Six compounds corresponding to six individual changed peaks were tentatively identified by matching with empirical molecular formulae and mass fragments. Conclusion The manufacturing procedure for PRZA was standardized. This protocol can be used for PRZA industrial production. The bioactivity assay results of raw PR and PRZA (produced using the standardized protocol) support the common practice for the clinical applications of these two decoction pieces. Moreover, raw PR and PRZA showed different chemical profiles. Further studies are warranted to establish the relationship between the alteration of chemical profiles and the changes of medicinal properties caused by processing.

The Young's modulus and residual stresses of electroplated copper film microbridges were measured. Special ceramic shaft structure was designed to solve the problem of getting the load-deflection curves of the microbridges from a nanoindentation system equipped with a normal Berkovich probe. Theoretical analysis of the load-deflection curves of the microbridges is proposed to evaluate the Young's modulus and residual stress of the copper films simultaneously. The calculated results based on the experimental measurements showed that the average Young's modulus and residual stress of the electroplated copper films are 115.2 GPa and 19.3 MPa, respectively, while the Young's modulus measured by the nanoindenter for the same copper film with silicon substrate is 110±1.67 GPa.

Fe-Si/Cr multilayered films with amorphous magnetic Fe-Si layers have been prepared with the rf-sputtering method at different Ar charging pressures. Samples with antiferromagnetic exchange coupling can be obtained only at a higher Ar charging pressure, ${\mathit{P}}_{\mathrm{Ar}}$. When ${\mathit{P}}_{\mathrm{Ar}}$=5 mTorr and the Fe-Si layers are as thin as 19 \AA{}, an oscillatory function of magnetization versus the thickness of Cr layers with a period of about 10 \AA{} is obtained. This is an effect specific to interlayer coupling in the multilayered films, and is caused by oscillatory changes of the internal field in Fe-Si layers.

CoNb/Cu multilayers with amorphous CoNb magnetic layers were prepared by rf-sputtering method and then annealed at various temperatures in a high vacuum. A maximum magnetoresistance ratio of 2.83% at room temperature was obtained under a relatively low saturation field of about 200 Oe for the optimum annealing temperature of 400° C. The structural, magnetic and transport properties were strongly influenced by the annealing temperature, and the transport properties were explained on the basis of granular multilayered structures. The magnetoresistance ratio also depends on the thickness of CoNb and Cu layers.