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Lactobacillus rhamnosus zz-1 can alleviate stress-induced depression-like behavior and physiological abnormalities, which is related to its regulation of the intestinal microecology (including the intestinal function and microbiota).

Although monosodium glutamate (MSG) is a widely used food additive, its safety and systemic side effects have not been fully clarified. The intestinal flora is closely associated with human health; however, it remains unclear whether MSG consumption can affect health by acting on the intestinal flora. In this study, serum biomarkers, intestinal structure, intestinal immunity, and intestinal flora were examined to investigate the effects of different doses of sodium glutamate on the body, intestinal function, and intestinal flora of mice. The results showed that 30 mg/kg MSG had no significant effect on serum C-reactive protein, trimethylamine N-oxide, angiotensin II, intestinal interleukin (IL)-1β, IL-6, tumor necrosis factor-α, secretory IgA and fecal albumin in mice, but also promoted intestinal development and regulated the intestinal flora. Moreover, 1500 mg/kg MSG increased the risk of cardiovascular disease and damaged the intestinal structure and flora. In this study, MSG was also found to be healthier than salt at the equivalent sodium concentration. Collectively, these findings suggested that low doses of MSG were safe for mice and may have some health benefits as a probiotic by promoting intestinal development and regulating the intestinal flora.

Cu3NbSe4 nanocrystals with a cubic phase, monodisperse size and uniform shape synthesized by a facile colloidal method exhibit excellent optoelectronic properties.

Cubic phase, monodispersed size and uniform shape Cu2GeTe3 nanocrystals exhibiting excellent optoelectronic properties have been for the first time synthesized by a facile colloidal method.

Large amounts of uranium-containing radioactive waste are generated in reactor operation and in the research and manufacture of nuclear fuel elements. At present, there are various uranium enrichment and separation methods such as reduction precipitation method, ion exchange method, solvent extraction method, membrane filtration method, adsorption method, and microorganism method to treat the uranium-containing radioactive waste generated in the related processes of nuclear facilities. However, the airborne effluent or liquid effluent discharged after treatment may still contain radioactive uranium. It is well known that uranium is a radioactive heavy metal element, and its radioactive and chemical toxicity cannot be ignored. Uranium in the environment enters the human body through the food route, and its long half-life can make the human body suffer from continuous radioactive internal radiation damage. As an environmental medium, organisms are closely related to the entry of uranium into the human body through food. Therefore, it is of great significance to carry out accurate measurement of uranium content in environmental-grade biological samples around nuclear facilities, however, complete and accurate measurement results include measurement data and uncertainty. Laser fluorescence method is a method for rapid analysis of uranium content in environmental samples. It has the advantages of high sensitivity, simple sample pretreatment, and wide measurement range, which has been widely used in nuclear industry, environmental monitoring and scientific research. At present, there is a lack of relevant reports on the uncertainty of the measurement of total uranium content in environmental-grade biological samples by laser fluorescence method. It is of great significance to accurately measure the uranium content in biological samples by evaluating the uncertainty of this method. In this paper, the WGJ-III trace uranium analyzer was used to analyze the uncertainty source of total uranium in environmental-grade biological samples by laser fluorescence method. The uncertainty measurement model was established, the uncertainty components were quantified, and the expanded uncertainty of the measurement of total uranium content in environmental biological samples was calculated. The evaluation results showed that the expanded uncertainty of a 0.05 g environmental biological sample is 10.8% (k = 2) without dilution, and the dominant uncertainty component is derived from the measurement uncertainty of sample fluorescence counting.

Conductive hydrogels have attracted extensive interest owing to its potential in soft robotics, electronic skin, and human monitoring. However, insufficient mechanical properties, lower adhesivity, and unsatisfactory conductivity seriously hinder potential applications in this emerging field. Herein, a highly elastic conductive hydrogel with a combination of favorable mechanical properties, self-adhesiveness, and excellent electrical performance was achieved by the synergistic effect of aminated lignin (AL), polydopamine (PDA), polyacrylamide (PAM) chains, and biomass carbon aerogel (C-SPF). In detail, AL was applied to induce slow oxidative polymerization of DA for preparing the sticky hydrogel containing PDA. Then, C-SPF carbon aerogel was used as a matrix to construct a dual-network structured composite hydrogel by combining with the hydrogels derived from PDA, AL, and PAM. The as-prepared conductive hydrogel displayed excellent mechanical performance, strong adhesive strength, and repeatable adhesivity. The prepared hydrogel-based pressure sensor possessed fast response (0.6 s loading and 0.8 s unloading stress time), high response (maximum RCR = 1.8 × 10

Valorization of agro-wastes into high performance functional materials is a topic that is receiving growing interest. Agro-wastes could be converted into biochar by slow pyrolysis and could be even given high added value by in situ deposition of nanoparticles. Herein, we investigate for the first time the impregnation of copper and nickel nitrates on sugarcane pulp bagasse powder and its slow pyrolysis at 500 °C. The process permitted to obtain unusual hierarchically structured porous biochar material with 40 nm-sized immobilized bimetallic copper-nickel alloy nanoparticles. The materials were characterized by XRD, XPS, Raman spectroscopy, TGA and SEM. As the pure biochar does not exhibits any highly porous structure, it is suggested that copper and nickel salts, or the metallic nanoparticles, are responsible for the fishing net-like structure obtained for the underlying biochar. The alloyed metal nanoparticles are extremely well dispersed over the biochar, with narrow size distribution (403 nm). This work clearly demonstrates that sugarcane pulp bagasse has a particular behavior and could provide highly porous biochar, in one step, for catalytic and other applications where high porosity and surface area are required. More importantly, such a porosity does not require any harsh acidic or basic treatment, and only the catalyst precursors are required.

Shaddock peel, a crop by-product mainly composed of cellulose, hemicellulose, lignin, and pectin, was developed as a flexible sensitive material for detecting environmental external pressure. Firstly, a natural carbon framework (C-SPF) with high conductivity was prepared using hydrothermal treatment followed by carbonization. Then, the PDMS elastomer was coated on the C-SPF instead of dense filling to convert the brittle C-SPF into elastic porous materials (M-SPF). Benefiting from the large deformation space of the porous framework and the stable interactions between PDMS and C-SPF, M-SPF exhibited ultrahigh coercibility (up to 99.0% strain) and high elasticity (99.4% height retention for 10 000 cycles at 50.0% strain). The M-SPF-based pressure sensor also exhibited a quick response (loading and unloading times were 20 ms and 30 ms), high sensitivity (63.4 kPa−1), wide working range (from 0 to 800 kPa), and stable stress-electric current response (10 000 cycles). These advantages open a door to a variety of applications, such as flexible wearable devices, which demonstrated human physiological signal monitoring. The low cost, simple design and portable use of piezoresistive sensors highlight the potential application of the crop by-product shaddock peel as a high-value material.

This study aimed to evaluate the effects of partial reducing rumen-protected Lys (RPLys) on rumen fermentation and microbial composition in heifers. Three ruminal fistulated Holstein Friesian bulls were used to determine the effective degradability of RPLys using an in situ method at incubation times of 0, 2, 6, 12, 16, 24, 36, and 48 h. Thereafter, 36 Holstein heifers at 90 days of age were assigned to one of two dietary treatments: a theoretically balanced amino acid diet (PC group; 1.21% Lys, 0.4% Met) or a 30% Lys-reduced diet (PCLys group, 0.85% Lys, 0.4% Met). Rumen fluid samples from five heifers in each group were extracted using esophageal tubing on day 90 to determine pH, microprotein, ammonia, volatile fatty acids, and microbial communities. Results showed that the effective ruminal degradability was 25.76%. Furthermore, differences in rumen fermentation parameters and alpha diversity of the microbiota between the two groups were not significant, but beta diversity was significant. Based upon relative abundance analysis, short-chain fatty acid-producing bacteria, including Sharpea, Syntrophococcus, [Ruminococcus]_gauvreauii_group, Acetitomaculum, and [Eubacterium]_nadotum_group belonging to Firmicutes, were significantly decreased in the PCLys group. Spearman's analysis revealed a positive correlation between the butyrate molar proportion and the relative abundance of butyrate-producing bacteria such as [Eubacterium]_nadotum_group, Coprococcus_1, Ruminococcaceae_UCG_013, Pseudoramibacter, and Lachnospiraceae_UCG_010. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States analysis further validated that RPLys deduction influenced energy metabolism. Together, our findings highlight the role of RPLys or Lys in butyrate-producing bacteria. However, the number of bacteria affected by Lys was very limited and insufficient to alter rumen fermentation. Key Points • Reducing 30% Lys via rumen-protected Lys did not affect rumen fermentation parameters and alpha diversity of microbiota of Holstein heifers. It meant that the ruminal fermentation pattern was not changed. • Reducing 30% Lys via rumen-protected lysine significantly decreased relative abundance of short-chain fatty acid-producing bacteria belonging to Firmicutes. • Functions of microorganisms were changed by reducing 30% Lys via rumen-protected Lys, especially amino acid metabolism. It may affect the amino acid composition of microprotein.

Zein is commonly used to construct food flavonoid delivery systems. This study investigated the effect and mechanism of zein on the digestive stability of five citrus flavonoids, namely hesperetin (HET), hesperidin (HED), neohesperidin (NHD), naringenin (NEN), and naringin (NIN).Zein enhanced the digestive stability of the five citrus flavonoids, especially that of HET and NEN, during digestion in the stomach and small intestine. Fluorescence spectroscopy results suggested that citrus flavonoids spontaneously quenched the endogenous fluorescence of zein in static quenching mode. The binding of HET, HED and NHD to zein was driven respectively by electrostatic, hydrophobic and electrostatic interaction. However, Van der Waals' force and hydrogen (H)-bond interaction represented the primary driving force for binding NEN, and NIN to zein to form complexes. The binding of the five citrus flavonoids to zein also caused a diverse bathochromic shift in ultraviolet absorbance. Analysis using Fourier-transform infrared and Raman spectroscopy revealed that the binding behavior of the five citrus flavonoids had different effects on changes in the secondary structures, disulfide bonds, and tyrosine exposure of zein. The results were also partially verified by molecular dynamic simulation.Zein enhanced the digestive stability of the five citrus flavonoids via different binding interactions that was due to the difference in molecular structure of citrus flavonoids. © 2022 Society of Chemical Industry.

High photocatalytic hole-electron pairs separation efficiency and the wide use of inexpensive and earth-abundant materials as cocatalysts in most semiconductor-based photocatalytic systems are desired for improving the photocatalytic activity and practical application. Herein, we report a facile one-pot solvothermal approach of integrating stable metallic nonmetal materials 1T-MoS2 nanosheets with MIL-53(Fe) to form needle-shaped 1T-MoS2@MIL-53(Fe) (TSMF) composites. Interestingly, the introduction of 1T-MoS2 turns nonspecial-structured MIL-53(Fe) into needle-like structure and the BET analysis reveals that the optimal TSMF composites possess abundant coexistence of micropores and mesopores with a large surface area of 337 m2 g−1, which is about 16 folds higher than that of the pure MOFs. Meanwhile, it is remarkable that the photocatalytic rate of ibuprofen (IBP) by optimal TSMF nanocomposites has improved 7.5 and 9.4 times compared to the pristine MIL-53(Fe) and 1T-MoS2, respectively. The photocatalytic efficiency of TSMF composites enhances due to the emerging micropores, which can provide more adsorption and reaction sites. In addition, the formed compact and uniform interface contact between 1T-MoS2 sheets and MOF may dramatically accelerate the separation of the photo-induced charges, thus enhance the photocatalytic activity. We also study the photocatalytic mechanism combined the corresponding electrochemical testing and the photo-degradation intermediates identified by ion chromatography (IC) and LC–MS-MS, indicating that superoxide radicals ( O2–), hydroxyl radical ( OH) and electrons (e−) are the main active radicals in IBP photocatalysis and decarboxylation and hydroxylation are the main degradation pathways of IBP.

High electron-hole separation efficiency and wide spectrum absorption are desired for improving the photocatalytic activity. In this research, we integrate plasmonic Ag/AgCl with a typical semiconductor-like metal-organic framework MIL-88A(Fe) to form Ag/AgCl@MIL-88A(Fe) (ACMA) nanocomposites by a facile one-pot solvothermal method. The results demonstrate that ACMA nanocomposites not only broaden the visible-light absorption of MOFs, but also greatly accelerate photo-induced charge transfer rate. EDS mapping and HRTEM results suggest that Ag/AgCl is uniformly and densely dispersed on the surface of MOF, which is beneficial for charge flow and expedites the charge migration. By virtue of the structural and compositional features, these unique ACMA nanocomposites perform excellent photocatalytic activity on ibuprofen (IBP) in terms of high degradation efficiency, high mineralization and excellent cycling stability. ACMA-2 (Fe:Ag = 2:1) displays highly efficient photocatalytic activity on IBP under visible light irradiation, and the corresponding photo-degradation rate is 10.8 and 40.4 folds higher than that of MIL-88A(Fe) and Ag/AgCl, respectively. Total organic carbon (TOC) removal of IBP photodegradation reaches 91% by the catalysis of ACMA-2. Combined with the electrochemical tests, quencher experiments and analysis of related degradation products identified by ion chromatography (IC) and LC-MS-MS, oxidation by superoxide radicals ( O2−) as well as holes (h+) and electrons (e−) is the dominant degradation process in the photocatalytic degradation of IBP. This work provides a new perspective for the preparation of environment-stable and efficient MOF-based photocatalysts by steering charge flow.

The present work reported the porous rhombic dodecahedral Co3O4 catalysts undergoing ZIF-67 calcination in air condition at different temperatures. The structural and textural properties of the obtained catalysts were fully characterized using scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N2 adsorption–desorption, and X-ray photoelectron spectroscopic (XPS). H2-temperature-programmed reduction (H2-TPR) was used to test their redox properties. Both surface structure and morphology of Co3O4 catalysts exhibited good correlation with their catalytic activity. The results demonstrated that the catalyst calcined at 500 °C (Co3O4-500) exhibited the best performance with respect to the complete CO conversion temperature at 115 °C. This finding was reproducible and tentatively attributed to the unique structure, higher amount of surface Co2+ and adsorbed oxygen species, and good low-temperature reduction behavior. Finally, the effect of water vapor on catalytic activity was also determined, which indicated that the addition of water vapor to the feedstock had a negative effect on CO conversion over Co3O4-500.

Effects and mechanism of polyols (mannitol, isomalt or xylitol) on the retrogradation of wheat starch (WS) were investigated by rapid viscosity analysis (RVA), rheological properties, fourier-transform infrared spectroscopy (FTIR), low-field nuclear magnetic resonance (LF-NMR), texture profile analysis (TPA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) in this study. A decrease in peak viscosity, trough viscosity, breakdown, final viscosity and setback of WS was observed with addition of polyols. The storage modulus (G′) and the change rate of G′ in the presence of polyols were significantly reduced. The number of hydrogen bonds increased accordingly and polyols in starch gel could combine with more water and reduce water migration. After 4 weeks storage at 4 °C, the hardness, retrogradation enthalpies (△H), crystallization rate constant (k) and relative crystallinity (RC) of WS/polyols were significantly reduced compared with those of the blank. Hence, polyol was promising to be a useful additive to inhibit the retrogradation of wheat starch, which provided a reference for inhibiting the retrogradation of starch-containing food.

Nanocomposites of organic nano-montmorillonite (nano-OMMT)-filled immiscible polyamide 6 (PA6)/polystyrene (PS) blends were prepared by three different processing methods. Masterbatch M1 of OMMT/PA6 and masterbatch M2 of OMMT/PS were prepared as separate masterbatchs by melt mixing with PA6 or PS, and then either mixed together or each mixed individually with appropriate amounts of PS or PA6, respectively. The effects of nano-OMMT content and processing method on the structure, phase morphology, and mechanical properties of the PA6/PS/OMMT nanocomposites were investigated by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and mechanical properties tests. The results showed that the nano-OMMT by M1 and M2 masterbatches dispersed primarily as exfoliated platelets in the PA6 matrix in the final composites regardless of the method of preparation. A drastic decrease of dispersed PS phase size and a very homogeneous size distribution were observed with the addition of nano-OMMT. The PA6/PS/OMMT nanocomposites prepared from the M2 displayed the smallest dispersed PS phase size and best distribution of OMMT. The improvement of the mechanical properties of the PA6/PS/OMMT nanocomposites was attributed to the enhanced compatibilization of the immiscible PA6/PS blends by using nano-OMMT. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers

In this article, an efficient and simple approach for the preparation of organic–inorganic intumescent interfacial flame retardants, aiming at enhancing the flame-retardant efficiency and interfacial adhesion between matrix and flame retardants was presented. The expandable graphite (EG) was functionalized by using a grafting process containing phosphorous, resulting in the formation of organic–inorganic intumescent flame retardants. Based on the successful grafting reaction, a series of flame-retardant polypropylene (PP) composites with different content of modified EG (MEG) were prepared and evaluated. With the incorporation of 30 wt% of MEG into PP, the satisfactory UL-94 flame retardant grade (V-0) and limiting oxygen index (LOI) as high as 25.3% were obtained. The residues of the PP/MEG composites were significantly increased with PP/EG and PP/EG/DOPO composites. Moreover, the residual char of PP/MEG composites is more compact and integrated. In addition, the formation of organic side chains on the MEG surface by the grafting reaction also contributed to an improvement in the interfacial compatibility, leading to an enhancement in mechanical properties of the composites compared with the PP composites filled with EG. The interfacial grafting flame retardants provided a novel way to prepare organic–inorganic intumescent flame retardants and the as-prepared flame retardants exhibited excellent flame retardant efficiency.

Background: Human are often simultaneously exposed to polycyclic aromatic hydrocarbons (PAHs) and metals, yet relatively little is known regarding their co-exposure effects on oxidative damage. Genetic factors and the gene-environment interactions can also determine the severity of oxidative damage. Four polymorphisms in microRNA (miRNA) genes (rs11614913, rs2292832, rs2910164, and rs3746444) have been well-studied to be associated with oxidative damage-related diseases. Objective: To investigate the influences of PAH-metal co-exposure, four polymorphisms, and their interactions on oxidative damage levels. Methods: We conducted a cross-sectional study in 1385 coke oven workers. We quantified exposure levels of PAHs and metals by urinary monohydroxy-PAHs, plasma benzo[a]pyrene-7,8-diol-9,10-epoxide-albumin adducts, and urinary metals, respectively, and measured oxidative damage levels by 8-iso-prostaglandin-F2α and 8-hydroxydeoxyguanosine. We also genotyped four polymorphisms. Results: In multiple-pollutant models, 8-iso-prostaglandin-F2α and 8-hydroxydeoxyguanosine were associated with multiple PAH exposure biomarkers, as well as with multiple metals (ptrend 7.75%, false discovery rate-adjusted pinteraction ≤ 2.25 × 10−5). Significantly higher 8-hydroxydeoxyguanosine was observed in carriers of rs11614913 CC variant homozygote than TC carriers (p = 0.037). Associations of the number of rs11614913 C allele with increased 8-iso-prostaglandin-F2α and 8-hydroxydeoxyguanosine were significant (βstd > 0, ptrend

In this work, sodium dodecyl sulfate (SDS) was used to obtain organically-modified layered double hydroxide (OMgAl-LDH) by anion-exchange reaction. The PLLA/LDH nanocomposites were prepared via direct melt intercalation. The results from both XRD patterns and FTIR spectra showed that SDS entered into the layers of LDH successfully and the layer space was increased from 0.756 to 1.64 nm. For the PLLA/LDH nanocomposites, the increase of the layer space was verified by the good dispersion of LDH in the PLLA matrix from the SEM images. The rheological analysis showed that the typical Newtonian behaviour shifted to shear-thinning behaviour with the addition of LDH. In addition, DSC data illustrated that the glass transition temperature of the PLLA/LDH nanocomposites decreased and the crystallinity of PLLA increased due to the addition of LDH, which indicates that LDH acts as a heterogeneous nucleating agent and induces the crystallization of PLLA. The modified LDH provided a better nucleating effect than the unmodified LDH. TGA results showed that OMgAl-LDH in the PLLA matrix caused earlier initial decomposition, suggesting that the presence of LDH decreased the thermal stability of the PLLA matrix.

In this work, the flammability behaviors and synergistic effects of red phosphorus masterbatch (RPM) with expandable graphite (EG) in flame-retardant high-density polyethylene/ethylene vinyl-acetate copolymer (HDPE/EVA) composites have been investigated by limiting oxygen index (LOI), UL-94 test, cone calorimeter test (CCT), thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR) and scanning electron microscopy (SEM). The data obtained from LOI, UL-94 test and CCT showed that suitable amount of RPM had synergistic effects with EG in the HDPE/EVA/EG/RPM composites. The addition of RPM greatly increased the LOI values by 3.4%, obtained UL-94 V-0 rating, decreased the heat release rates and total heat release, and prolongated the ignition time when 6.7 phr RPM substituted for EG in the HDPE/EVA/EG/RPM composites. The data from TGA and FTIR spectra also indicated the synergistic effects of RPM with EG considerably enhanced the thermal degradation temperatures. The morphological observations after UL-94, CCT, and SEM images presented positive evidences that the synergistic effects took place for RPM with EG, and the flame-retardant mechanism has been changed in flame-retardant HDPE/EVA/EG/RPM composites. The formation of stable and compact charred residues promoted by RPM acted as effective heat barriers and thermal insulations, which improved the flame-retardant performances and prevented the underlying polymer materials from burning. POLYM. ENG. SCI., 55:2884–2892, 2015. © 2015 Society of Plastics Engineers

Poly(d-lactide)–Pluronic F68–poly(d-lactide) (PDLA–Pluronic F68–PDLA) multiblock copolymer is synthesized and incorporated into poly(lactic acid) (PLA) as a novel tough agent by melting blend. The 1H NMR spectrum shows the PDLA–Pluronic F68–PDLA multiblock copolymer is synthesized successfully. The presence of the polylactide stereocomplex in the blends is confirmed by Infrared spectroscopy (IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Polarization optical microscopy (POM) shows that the crystal morphology of the stereocomplex crystals is different from that of neat PLA. PLA/multiblock copolymer blends have a continuous amorphous phase with crystalline regions being the discontinuous portion. In addition, the thermal properties of the tough PLA are improved because of the presence of the stereocomplex from the results obtained by DSC and thermogravimetric analysis (TGA). The improvements in mechanical properties potentially can increase the utility of this biomass-based polymer. Both types of morphological features can contribute to the improvement in mechanical properties. Therefore, the successful toughening behaviors in PLA may be due to several mechanisms working synergistically.

In this article, a novel intumescent alumina–silica hydrogel double shell microencapsulated ammonium polyphosphate flame retardant is prepared and filled into polypropylene as a flame retardant. The structure and properties of alumina–silica hydrogel double shell microencapsulated ammonium polyphosphate are characterized by Fourier transform infrared, scanning electron microscopy, and thermogravimetric analysis. The results show that the Al and Si groups are attached to the surface of ammonium polyphosphate. The flame retardancy, morphology of char layers, thermal properties, and mechanical properties of the polypropylene/alumina–silica hydrogel double shell microencapsulated ammonium polyphosphate composites are evaluated by limiting oxygen index, UL-94 test, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and mechanical properties test. The results show that alumina–silica hydrogel double shell microencapsulated ammonium polyphosphate can improve the thermal stability and charred residues at high temperature. In addition, the combination of alumina–silica hydrogel double shell microencapsulated ammonium polyphosphate and polyamide 6 shows more compact, firm, and continuous charred layers, resulting in better flame retardant performances. The limiting oxygen index value for polypropylene/alumina–silica hydrogel double shell microencapsulated ammonium polyphosphate/polyamide 6 composites can reach 25.6 and obtain a UL-94 V-0 rating. Also, polypropylene/alumina–silica hydrogel double shell microencapsulated ammonium polyphosphate/polyamide 6 composites present better mechanical properties than polypropylene/ammonium polyphosphate/polyamide 6 composites at the same content of flame retardant and polyamide 6.

In this article, elastomer-toughened high density polyethylene/magnesium hydroxide (HDPE/MH) composites with various contents of ethylene vinyl acetate copolymer (EVA) are prepared in a twin-screw extruder and then injection-molded. The effect of EVA on the viscoelastic, crystallization, morphology, and tensile properties of the HDPE/EVA/MH composites is studied. The rheological behaviors show that the complex viscosity, storage, and loss modulus at low frequencies are largely unaffected with various EVA contents; however, the corresponding values decrease with increasing EVA content at high frequencies. The scanning electronic microscopy studies on the HDPE/EVA/MH composites show that the MH particles mainly disperse in the EVA phase, and the interfacial adhesion has been also enhanced due to the addition of EVA. The crystallization of HDPE diminishes because of the surface energy difference resulting in encapsulation structure. The tensile properties of the HDPE/EVA/MH composites are strong influenced by the incorporation of EVA. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers

In this work, the flame-retardant high-density polyethylene/ethylene vinyl-acetate copolymer (HDPE/EVA) composites have been prepared by using expandable graphite (EG) as a flame retardant combined with ammonium polyphosphate (APP) and red phosphorus masterbatch (RPM) as synergists. The synergistic effects of these additives on the flammability behaviors of the filled composites have been investigated by limiting oxygen index, UL-94 test, cone calorimeter test, thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR), and scanning electron microscopy. The results show that APP and RPM are good synergists for improving the flame retardancy of EG-filled HDPE/EVA composites. The data from TGA and FTIR spectra also indicate the synergistic effects of APP and RPM with EG considerably enhance the thermal degradation temperatures but decrease the charred residues of the HDPE/EVA/EG composites because the flame-retardant mechanism has changed. The morphological observations present positive evidences that the synergistic effects take place in APP and RPM with EG in flame-retardant EG-filled HDPE/EVA/EG composites. The formation of stable and compact charred residues promoted by APP and RPM with EG acts as effective heat barriers and thermal insulations, which improves the flame-retardant performances and prevents the underlying polymer materials from burning. Copyright © 2015 John Wiley & Sons, Ltd.

In this work, polyamide 6 (PA6) as a charring agent has been used in combination with thermoplastic polyurethane (TPU)-microencapsulated ammonium polyphosphate (MTAPP) forming intumescent flame retardants (IFRs) which applies in polypropylene (PP). The effects of the IFRs on the flame retardancy, morphology of char layers, water resistance, thermal properties and mechanical properties of flame-retardant PP composites are investigated by limiting oxygen index (LOI), UL-94 test, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical properties test. The results show that the PP/MTAPP/PA6 composites exhibit much better flame-retardant performances than the PP/MTAPP composites. The higher LOI values and UL-94 V-2 of the PP/MTAPP composites with suitable amount of PA6 are obtained, which is attributed to the thick and compact char layer structure evidenced by SEM. The results from TGA and DSC demonstrate that the introduction of PA6 into PP/MTAPP composites has a great effect on the thermal stability and crystallization behaviors of the composites. Furthermore, the mechanical properties of PP/MTAPP/PA6 composites are also improved greatly due to the presence of PA6 as a charring agent. POLYM. ENG. SCI., 55:1355–1360, 2015. © 2015 Society of Plastics Engineers

In this work, red phosphorus masterbatch (RPM) was filled into polypropylene/thermoplastic polyurethanes (PP/TPU) blends as a halogen-free flame retardant. The flammability behaviour, thermal stability and mechanical properties were investigated by limit oxygen index (LOI), UL-94 vertical burning, cone calorimeter tests (CCT), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that the addition of RPM improved the flame retardant performance of PP/TPU blends. The LOI values of the composites with RPM were higher than that of the PP/TPU blends, and the UL-94 V-2 rating was achieved for PP/TPU/RPM composites. The CCT results further indicated that the heat release rates (HRR), total heat release (THR), and the CO2 production rate (CO2P) decreased in comparison with the PP/TPU blends. TGA data indicated that RPM greatly enhanced the thermal stability and char residues of PP/TPU blends. The addition of RPM deteriorated the tensile strength of the PP/TPU/RPM composites. However, the impact strength of the composites was improved.

[Research objective] Analyze the influencing factors of clinical teachers’ job satisfaction. [Research method] The ERG theory was used as the framework to design the questionnaires. Data were analyzed by structural equation model for investigating the influencing factors. [Research result] The modified model shows that factors of existence needs and growth needs have direct influence on the job satisfaction of clinical teachers, the influence coefficients are 0.540 and 0.380. The three influencing factors have positive effects on each other, and the correlation coefficients are 0.620, 0.400 and 0.330 respectively. [Research conclusion] Relevant departments should take active measures to improve job satisfaction of clinical teachers from two aspects: existence needs and growth needs, and to improve their work enthusiasm and teaching quality.

Objective: Analyze the relationship among medical students’ communication skills, communication willingness, environmental perception and the performance of doctor-patient communication. Methods: Based on the qualitative interview and theoretical research framework proposition, the study adopted regression analysis to analyze the reciprocate relationship among different variables and verified related propositions. Results: The score of medical students’ doctor-patient communicative skills is 3.49±0.41. That of communicative tendency is 3.62±0.72. That of environmental perception is 3.46±0.68. And that of communicative performance is 3.60±0.66. In conclusion, single-child medical students in urban areas perform better in communication between doctors and patients. The regression coefficient of communicative skills to performance and tendency is 0.763 and 0.660 respectively. The regression coefficient of communicative tendency to performance is 0.562. The regression coefficient of interaction item between environment perception and communicative skills to communicative tendency and performance is 0.430 and 0.619 respectively. Conclusions: Communicative skill has a positive effect on communicative performance of doctor-patient relationship. Communicative tendency plays a role of intermediary agent between communicative skill and performance. Environmental perception has an up-regulated effect on the relation between skills and tendency, and that of communicative skills and performance as well.

The isothermal section of the phase diagram of the Dy–Ho–Co ternary system at 773 K has been investigated by X-ray powder diffraction (XRD), differential thermal analysis (DTA), optical microscopy and scanning electron microscopy (SEM) techniques. The existence of 14 binary compounds Dy 2 Co 17 , Ho 2 Co 17 , Dy 2 Co 7 , Ho 2 Co 7 , DyCo 3 , HoCo 3 , DyCo 2 , HoCo 2 , Dy 4 Co 3 , Ho 4 Co 3 , Dy 12 Co 7 , Ho 12 Co 7 , Dy 3 Co and Ho 3 Co have been confirmed in this system at 773 K. The Dy and Ho, Dy 2 Co 17 and Ho 2 Co 17 , Dy 2 Co 7 and Ho 2 Co 7 , DyCo 3 and HoCo 3 , DyCo 2 and HoCo 2 , Dy 4 Co 3 and Ho 4 Co 3 , Dy 12 Co 7 and Ho 12 Co 7 , Dy 3 Co and Ho 3 Co form continuous solid solutions, respectively. No ternary compound was found. The isothermal section consists of nine single-phase regions and eight two-phase regions. There is no three-phase region in the isothermal section.

In order to determine the existence of phases and relationships in the Er–Fe–Mn system at 773 K, we have carried out this work mainly by X-ray powder diffraction with the aid of differential thermal analysis and have obtained the conclusions below. The existence of seven binary compounds ErFe 2 , ErFe 3 , Er 6 Fe 23 , Er 2 Fe 17 , ErMn 12 , Er 6 Mn 23 , ErMn 2 and one intermediate solid solution γ(Fe·Mn) have been confirmed in this system. Er 6 Fe 23 and Er 6 Mn 23 form continuous solid solution Er 6 (Fe 23− X Mn X ) (0 ≤ X ≤ 23). At 773 K, the maximum solid solubility of Fe in αMn, ErMn 12 , ErMn 2 phases and Mn in ErFe 2 , Er 2 Fe 17 , αFe phases are about 31, 69, 13 at% Fe and 47, 28, 8 at% Mn, respectively. The homogeneity range of γ(Fe·Mn) phase extended from about 34 at% Mn to 52 at% Mn. The maximum solid solubility of Er in γ(Fe·Mn) phase is about 2 at% Er. The isothermal section consists of ten single-phase regions, sixteen two-phase regions and seven three-phase regions. No ternary compounds were observed at 773 K in this system.

The isothermal section of phase diagram of the Ho–Mn–Ti ternary system at 773 K has been investigated mainly by X-ray powder diffraction analysis with the aid of differential thermal analysis in this work. The existence of eight binary compounds HoMn 2 , Ho 6 Mn 23 , HoMn 12 , Mn 5 Ti, Mn 2 Ti, βMnTi, αMnTi and Mn 15 Ti 85 has been confirmed in this system. At 773 K, the maximum solid solubility of Ti in αMn is about 8 at.%Ti. The homogeneity range of Mn 2 Ti extends from about 31 at.% to 39 at.% Ti. The maximum solid solubility of Ho in Mn 2 Ti phase is about less than 1 at.% Ho. The existence of solid solubility of other phases was not observed. No ternary compounds were found in this ternary system. At 773 K, the isothermal section of phase diagram of Ho–Mn–Ti ternary system consists of 11 single-phase regions, 19 two-phase regions and 9 three-phase regions.

In order to determine the existence of phases and relationships in the Er–Fe–Mn system at 773 K, we have carried out this work mainly by X-ray powder diffraction with the aid of differential thermal analysis and have obtained the conclusions below. The existence of seven binary compounds ErFe 2 , ErFe 3 , Er 6 Fe 23 , Er 2 Fe 17 , ErMn 12 , Er 6 Mn 23 , ErMn 2 and one intermediate solid solution γ(Fe·Mn) have been confirmed in this system. Er 6 Fe 23 and Er 6 Mn 23 form continuous solid solution Er 6 (Fe 23− X Mn X ) (0 ≤ X ≤ 23). At 773 K, the maximum solid solubility of Fe in αMn, ErMn 12 , ErMn 2 phases and Mn in ErFe 2 , Er 2 Fe 17 , αFe phases are about 31, 69, 13 at% Fe and 47, 28, 8 at% Mn, respectively. The homogeneity range of γ(Fe·Mn) phase extended from about 34 at% Mn to 52 at% Mn. The maximum solid solubility of Er in γ(Fe·Mn) phase is about 2 at% Er. The isothermal section consists of ten single-phase regions, sixteen two-phase regions and seven three-phase regions. No ternary compounds were observed at 773 K in this system.