Search

The oxide film could realize the formation of the chemical bonding between metal and plastic. In this study, surface pre-oxidation of AZ31B magnesium alloy was performed by two common methods to investigate the effect of oxide film on laser assisted joining of carbon fiber reinforced thermoplastic composites (CFRTP) and AZ31B. Oxide layer with porous structure was fabricated by micro-arc oxidation (MAO), in contrast to the dense and smooth oxide film produced by annealing. Both types of oxide film could effectively enhance the mechanical properties of the joint. Oxide layer could inhibit the decomposition of CFRTP and eliminate defects and relieve the residual stress because of the lower interfacial heat conduction. Porous structure of MAO coating further reduced the heat conduction. A new chemical bonding MgCO3 was identified at the joint with oxide. MAO coating could facilitate the formation of the new chemical bonding and enhance the mechanical interlocking, further strengthening the mechanical properties of the joint. The tensile-shear strengths of annealed and MAO joints were 8.8 MPa and 13.3 MPa respectively, reaching 1.60 and 2.41 times that of untreated joints (5.5 MPa). The MAO coating realized the comprehensive enhancement of AZ31B/CFRTP interface in terms of the interfacial heat transfer, mechanical interlocking and chemical bonding.

In magnetic coupling resonant wireless power transfer devices, planar spiral coils are often used as the coupling mechanism. In such application area, the coils are often wound sparsely with wide screw pitches and often under complex relative position. An accurate model of mutual inductance for planar spiral coils wound either densely or sparsely is established in this article. Utilizing Euler Angles, an exact expression of mutual inductance for a couple of planar spiral coils under arbitrary relative position is proposed. Based on this expression and geometric mean distance principle, a self-inductance expression for planar spiral coils is derived. Based on numerical calculation of the expressions proposed in this article, the influence of precession and spin angle on mutual inductance is studied; the method of determining radius of each turn when using traditional concentric circular filaments cluster approximation model for self- and mutual inductance calculation is studied; the difference of calculation results between the accurate model and the traditional approximation model is compared. Finite element simulation and experimental results verify the correctness of the proposed models.

Hypericum sampsonii Hance has traditionally been used to treat enteritis and diarrhea. As one of the main benzophenones isolated from H. sampsonii, 4-geranyloxy-2,6-dihydroxybenzophenonel (4-GDB) has been shown to possess anti-inflammatory effects. However, the therapeutic effect and potential mechanisms of 4-GDB in ulcerative colitis (UC) remain unclear. This study aimed to evaluate the role of 4-GDB in UC using a dextran sulfate sodium-induced colitis mouse model. Intragastric administration of 4-GDB (20 mg/kg/day) for 8 days significantly attenuated colonic injury, reduced the expression of inflammatory mediators, and improved colonic barrier function in mice with colitis. Furthermore, in vivo and in vitro experiments indicated that 4-GDB could activate cAMP/PKA/CREB and inhibit the NF-κB pathway. Collectively, 4-GDB may be a potential agent for treating UC by regulating the cAMP/PKA/CREB and NF-κB pathways.

Diglycolamides (DGAs) show excellent application prospects for the extraction and separation of rare earth metals from highly radioactive liquid wastes and rare earth ores. The extraction ability of DGAs for rare earth ions in nitrate or chloride media increases with increasing atomic number of the rare earth metal. To understand the origin of this phenomenon, three binuclear crystals [Ln(TEDGA)3][Ln(NO3)6] of N,N,N′,N′-tetraethyldiglycolamide (TEDGA) with rare earth ions La(III), Pr(III) and Eu(III) were prepared and characterized crystallographically. The three complexes belong to the triclinic crystal system, P-1 space group. The bond lengths of Ln–Oamide are significantly shorter than those of Ln–Oether in the same crystal. The Ln–Oamide and Ln–Oether bond lengths gradually decrease with increasing atomic number of the rare earth ion. The dihedral angle formed by TEDGA and metal ions through the tridentate coordination gradually increases with increasing metal ion atomic number, tending toward the formation of sizeable planar coordination structures for the most massive rare earth ions. The structures of the compounds formed by the extractant and metal ion were optimized by means of DFT simulations. We find that the interaction between TEDGA and the rare earth ion is dominated by electrostatic interaction by analyzing binding energy, WBIs, Mulliken charge, natural electron configurations, and molecular orbital interaction. The covalent component of the Ln–O bonds of the complexes increases with increasing metal atomic number. The observed increase in extraction and separation capacity of diglycolamides for rare earth ions with increasing atomic number might be due to the formation of two five-member rings by one tridentate ligand. The rare earth ions with large atomic numbers tend to form planar structures with large dihedral angles with DGA ligands.

Purpose: To investigate the effects of (-)-epigallocatechin gallate (EGCG) and quercetin on the activity and structure of α-amylase. Methods: The inhibitory effects of 7 functional factors were compared by measuring half maximal inhibitory concentration (IC50) values. Lineweaver-Burk plots were used to determine the type of inhibition exerted by EGCG and quercetin against α-amylase. The effect of EGCG and quercetin on the conformation of α-amylase was investigated using fluorescence spectroscopy. Results: Quercetin and EGCG inhibited α-amylase with IC50 values of 1.36 and 0.31 mg/mL, respectively, which were much lower than the IC50 values of the other compounds (puerarin, paeonol, konjac glucomannan and polygonatum odoratum polysaccharide). The Lineweaver−Burk plots indicated that EGCG and quercetin inhibited α-amylase competitively, with ki values of 0.23 and 1.28 mg/mL, respectively. Fluorescence spectroscopy revealed that treatment with EGCG and quercetin led to formation of a loosely-structured hydrophobic hydration layer. Conclusion: This study has unraveled the mechanism underlying the inhibition of α-amylase activity by EGCG and quercetin in vitro. This should make for better understanding of the mechanisms that underlie the antidiabetic effects of EGCG and quercetin in vivo.

Grid pattern was textured on Ti-6Al-4V alloy (TC4) substrate surface by nanosecond laser system. Laser joining of carbon fiber reinforced thermoplastic composite (CFRTP) to TC4 joints were performed, and the effect of texture grid depth was investigated. The contact angle of molten CFRTP on textured TC4 surface was measured and the tensile-shear force was tested. The fracture surface and interface morphology were observed. The results indicated that the wettability of molten CFRTP on TC4 surface improved remarkably after laser textured TC4. Shear force of CFRTP/TC4 joints was increased by 156% after laser textured TC4 surface. When the depth of grid was deeper than 100 μm, contact angle increased and incomplete filling of molten CFRTP in grid occurred, the shear force thus decreased gradually. Resin-carbon fibers mixture was adhered on the fracture surface of TC4, and the variation tendency of adhesion ratio was consistent with that of shear force. TC4 matrix was exfoliated from substrate and adhered at the fracture surface of CFRTP, indicating stronger mechanical interlocking occurred at the joining interface after laser textured TC4 surface. Beside mechanical interlocking, compound layer consisted of CTi0.42V1.58 carburization phase was also confirmed at interface, suggesting that chemical bonding also occurred at the joining interface.

Laser textured TC4 (Ti6Al4V) was connected with CFRP (carbon fiber reinforced plastic) by hot-pressing joining. Influence of textured grid width on tensile-shear force of joint was investigated, and the bonding status at the TC4/CFRP interface with and without laser texturing was compared. Experimental result indicated that laser texturing obviously improved the TC4 surface roughness and wettability of molten CFRP, which increased the interfacial joining area and thus enhanced the shear force of joint. When 0.2-mm-wide grid was adopted, surface roughness of the metal was increased by 14 times and the minimum contact angle of molten CFRP on TC4 was 49.9°. The maximum shear force was 5286 N in this case, which was about three times that of untreated case, and the adhesion ratio of resin-carbon fiber mixture also accomplished the maximum of 49.6 % of overlap area. When grid width became larger, the surface roughness and wettability decreased which caused incomplete filling of molten CFRP in textured grid and decrease of shear force. Interface and cohesive hybrid failure mode was observed from fracture surface. However, the part of oxide layer exfoliated from substrate occurred under the case of laser textured TC4 sheets, which was responsible for the enhancement of mechanical interlocking. Moreover, new chemical bonds between Ti and C were also discovered, justifying a further enhancement of tensile-shear forces.

Achieving strong joining of aluminum alloy to carbon fiber thermoplastic composites (CFRTP) using laser heating was an essential method to reduce the weight of structure and save energy. In current study, a silane coupling agent was adopted on the aluminum alloy surface to improve the bonding strength of the laser joining of aluminum alloy to CFRTP. Substrate characteristics of the aluminum alloy after treatment including surface morphology, surface roughness and wettability as well as chemical composition were then studied. For comparison, identical experiments were also performed for the polished and sanded aluminum alloy. Compared to the aluminum alloy polished, the surface roughness of aluminum alloy sanded and silane treated was increased, whereas the wettability was both decreased. The rougher surface led to a worse wettability of aluminum alloy surface for these two specimens. In addition, the detected organo-functional group for the latter was also responsible for the increase of water contact angle on the aluminum alloy surface. Compared to the polished specimens, the tensile shear force of joints for sanded and silane-treated substrates averaged 1106.9N and 2959.4N respectively, which represents a respective increase of 1.2 times and 3.3 times than the polished state. Correspondingly, the tensile shear strength of joints was 6.3MPa and 16.8MPa, which was increased by 1.1 times and 2.9 times, respectively. The improved mechanical interlocking induced by increasing the surface roughness in both sanded and silane treated cases was considered to strengthen the bonding strength at the interface. Moreover, for the joints fabricated by aluminum alloy silane treated and CFRTP, the remarkable enhancement of joint strength was also related to the formation of silane coupling film on the aluminum alloy surface. The tensile shear properties of joints were also found to have a positive influence in increasing the adhesion amount of CFRTP on the fractured surface of aluminum alloy. Finally, the silane treatment was expected to play a significant role in joining aluminum alloy to CFRTP.

Fiber laser joining of 6061 aluminium alloy and carbon fiber reinforced thermoplastic composite (CFRTP) was performed in this work. The effect of three process parameters including laser power, traveling speed and defocus distance on the bonding interface and joint properties was investigated. Shear tests were performed to evaluate the joint strength in different variables. X-ray photoelectron spectroscopy (XPS) was adopted to confirm the chemical states of elements at the interface. The results indicated that the shear strength of joints first increased and then decreased with the increase of heat input. Insufficient flow of CFRTP could not fill the grooves of aluminium alloy surface at low heat input. The resin was decomposed at excessisvely high heat input, causing pores remained at the interface. The fracture mode was determined as the interface failure. XPS result revealed that no new chemical bond was found at the interface, and the mechanical interlocking between aluminium alloy and CFRTP was main bonding mechanism. The maximum shear strength was 23.8 MPa, which was obtained as laser power, traveling speed and defocus distance was 1100 W, 5 mm/s and +10 mm, respectively.

α-Al2O3 nanoparticles are easy to agglomerate in the preparation, thereby leading to adverse effects during the applications. This paper reported the preparation of α-Al2O3 nanoparticles with good dispersity and controllable morphology by lowering temperature calcination of the precipitated precursor powders. The composite composed of PVP and ammonium sulfate is used to control the morphology and improve the precursor's dispersion. The influences of R ((NH4)2CO3/Al3+, molar ratio) and PVP-ammonium sulfate composite were studied thoroughly. It was found that an urchin-shaped ammonium aluminum carbonate hydroxide (AACH) precursor can be formed under the conditions of R = 3, and the ammonium sulfate and PVP are 20 wt% and 5 wt%, respectively. After calcination at 1000 °C for 2 h, such urchin-like precursor particles were converted to quasi-spherical and well crystallized α-Al2O3 nanoparticles, which possessed a narrow size distribution of 110 nm and a specific surface area of 12.13 m2/g. The resultant α-Al2O3 nanoparticles prepared by such a simple method were expected to be applied in transparent ceramics and high-performance catalysts.

Hypericum sampsonii Hance (Yuanbaocao), a traditional herbal medicine with various pharmacological properties, is traditionally used to treat diarrhea and enteritis in China for hundreds of years. Investigations have uncovered its anti-inflammatory effects and corresponding bioactive constituents in H. sampsonii, however, the mechanisms of action for the treatment of enteritis are still unclear.This study aims to investigate the therapeutic effects and molecular mechanisms of H. sampsonii in a dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice model.The major ingredients of the ethyl acetate extract (HS) in H. sampsonii were analyzed by UPLC-QTOF-MS. The inflammatory state of UC mice was caused by 3% DSS once daily for seven days. During DSS treatment, the mice in the positive drug group and the other three groups were orally administered 5-ASA (positive control) or HS daily. After treatment with HS or 5-ASA for a week, colonic pathological observation and the molecular biological index were performed for therapeutic evaluation, including visual inspection in the length and weight of colons and spleens, pathological morphology by hematoxylin and eosin (HE) staining, determination of oxidative markers, inflammatory cytokines and tumor necrosis factor-alpha (TNF-α) levels in colonic tissues as well as spleen index. Gene expression levels of inflammatory cytokines, antioxidant enzymes and PDE4 were detected using kits and PCR, while the expression of colonic tight junction proteins and relative signals of PKA/CREB signaling pathway were analyzed by Western blot.The main components in HS were found to be polycyclic polyprenylated acylphloroglucinols (PPAPs). HS distinctly alleviated DSS-stimulated UC-like lesions symptoms as evidenced by a significant recovery from body weight, colon lengths, and histological injuries of colons. HS reduced the accumulation of pro-inflammatory cytokines and improved the mRNA level of IL-10. Simultaneously, the colonic mRNA expression levels of IL-1β, IL-17, iNOS and COX-2 were all significantly suppressed by HS in a dose-dependent manner. Furthermore, HS restored the protein expression of tight junction-associated protein (ZO-1 and occluding). Besides, HS significantly inhibited the protein level of PDE4 and decreased the expressions of PKA and phosphorylated CREB.This is the first work about main composition and anti-UC effect of Hypericum sampsonii Hance. For the first time, this study reveals HS is not toxic in a single dose and exert significantly protective effect in DSS-colitis mice. The underlying mechanisms may involve the improvement to inflammatory status, the protection for intestinal barrier function, the inhibition of PDE4, and the activation of PKA/CREB signaling pathway. This study provided an experimental basis for the traditional application of H. sampsonii Hance in the treatment of diarrhea and dysentery.

Suppressing the anionic mobility in solid polymer electrolytes (SPEs) is crucial to mitigate the ionic conductivity and internal cell polarization, thus upgrading the stability and cycle life of rechargeable lithium-ion batteries (LIBs). Now, a series of novel conducting solid polymer electrolytes (CSPEs) with a zwitterionic structure comprising TEOS which was grafted to nitrogen-centered cations connected to hydrophilic sulfonate and carboxylate groups were used as SPEs in LIBs. The quaternized 1,8-diaminonaphthalene polyvinylidene difluoride lithium-ion conducting electrolyte (DN-PF-LCP) as an SPE component in LIBs achieves outstanding ionic conductivity (8.69 × 10−4 S cm−1), a sufficient capacity of 136 mA h g−1 with a decent capacity retention of 96% at a current rate of 0.3C over 200 cycles at 25 °C, and superior thermo-stability (∼420 °C). The zwitterionic structure of the DN-PF-LCP CSPE provides strong molecular interactions and efficiently facilitates the disintegration of Li+ ions, thus stimulating the mobility of Li+ ions within the CSPE and enhancing the Li+ ion conduction properties. The hydrogen bonding and ion–dipole interactions in the DN-PF-LCP CSPE provide nanosized self-agglomeration of anions and provide interaction between anions and their structurally homologous matrix, thus impeding the mobility of anions and lithium dendritic growth. These outstanding characteristics of DN-PF-LCP make it promising as a CSPE for LIBs.

Ulcerative colitis is a recrudescent intestinal inflammation coupled with diarrhea, weight loss, pus, and blood stool, which seriously impacts the quality of patient life. d-Pinitol, which can be a food supplement isolated from the food plant-like soybeans, Ceratonia siliqua Linn and Bruguiera gymnorrhiza, has been proved to show anti-oxidative and anti-inflammatory effects. However, the potential mechanism of d-pinitol still remains ill-defined contemporarily. In the current study, the therapeutic effect and potential mechanisms of d-pinitol against colitis were investigated. Oxidative stress and inflammation of experimental colitis were caused by 3% DSS treatment once daily for 7 days. During DSS treatment, the mice of the positive drug group and three other groups were orally administered SASP or d-pinitol once daily. Clinical symptoms were analyzed, and macroscopic scores were calculated. The levels of oxidative and inflammatory cytokines were measured using assay kits and RT-PCR. Additionally, the protein expression of the Nrf2/ARE pathway and PPAR-γ was measured by Western blot. Results showed that d-pinitol enormously alleviated DSS-induced bodyweight loss, colon shortening, and histological injuries, achieving a therapeutic efficacy superior to SASP. Moreover, the oxidative stress and colonic inflammatory response were mitigated. d-pinitol not only significantly activated the Nrf2/ARE signaling pathway via facilitating the translocation of Nrf2 from sitoplazma to cytoblast, upregulating the protein expression levels of GCLC, GCLM, HO-1, and NQO1, but also improved the PPAR-γ level by binding to the active site of PPAR-γ, when suppressing NF-κB p65 and IκBα phosphorylation. In conclusion, d-pinitol exhibited a dramatic anti-colitis efficacy by activating the Nrf2/ARE pathway and PPAR-γ. Hence, d-pinitol may be a promising therapeutic drug against UC in the future.

Purpose: To investigate the effect of Peony seed oil (PO) on non-alcoholic fatty liver disease (NAFLD), and the underlying mechanism of action. Methods: A mouse model of NAFLD was established using high-fat diet (HFD) for 12 weeks. Serum levels of triacylglycerol (TG), total cholesterol (TC), glucose and free fatty acids (FFAs) were determined. Activities of aspartate aminotransferase (AST) and alanine amino transferase (ALT) were assayed in liver homogenates, while mRNA and protein expressions of GRP78, x-box binding protein 1 (XBP1) and phosphorylated inositol-requiring enzyme 1 (p-IRE1α) were assayed in liver tissue using real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting, respectively. Expression levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were also determined by qRT-PCR. Results: HFD diet led to significant increases in body weight as well as serum TG, TC, glucose and FFA levels. However, treatment with PO significantly reversed the effect of HFD on these parameters (p < 0.05). The mRNA expression levels of TNF- α, IL-6 and IL-1β were significantly higher in HFD control group than in normal control group, but were significantly reduced after PO treatment (p < 0.05). The protein expression levels of GRP78, XBP-1 and p-IRE1α significantly increased in the liver of NAFLD group, when compared with normal control rats, but were significantly downregulated by treatment with PO (p < 0.05). Conclusion: PO attenuates HFD-induced NAFLD via inactivation of endoplasmic reticulum stress (ERS) pathway. Thus, PO has potentials for the treatment of NAFLD but further studies are required to ascertain this.