[en] Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells in a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection

[en] An automatic device for the effective and rapid measurement of electron beam emittance has been designed and installed in the laboratory of Tsinghua University. The computer control system of the 'Single slit-multiple wires' has been used for data acquisition and processing, and beam phase diagram displaying; for beam phase area and percentage of beam current strength and emittance calculation. The effects of cathod heating current of the electron gun on the initial emittance have been stuided preliminarily

[en] Parameters that vary monotonically with damage propagation are useful in condition monitoring. However, it is not easy to find such parameters especially for complex systems like pumps. A method using half and full spectra, fuzzy preference-based rough sets and principal component analysis (PCA) is proposed to generate such an indicator for tracking impeller damage in a centrifugal slurry pump. Half and full spectra are used for extracting features related to pump health status. A fuzzy preference-based rough set model is employed in the process of selecting features reflecting the damage propagation monotonically. PCA is used to condense the features and generate an indicator which represents the damage propagation. The effectiveness of the proposed method is tested using laboratory experimental data. Results show that the indicator generated by the proposed method can clearly and monotonically distinguish the health status of the pump impeller. (paper)

[en] A new molecularly imprinted stir bar was prepared using nicosulfuron, a sulfonylurea herbicide, as a template. To achieve the selective and direct extraction of a target analyte from aqueous samples, several main parameters, including extraction time, pH value and contents of inorganic salt in the sample matrix, were investigated. Competitive sorption experiments showed that using six sulfonylureas as substrates the imprinted stir bar gave high selectivity and imprinted effect on the template nicosulfuron in comparison with the non-imprinted stir bar. Evidence was also presented by the scanning electronic microscopic images of the imprinted and non-imprinted stir bars. This resulted in a combined imprinted stir bar-HPLC-UV method allowing the determination of trace nicosulfuron from the sample matrix. Based on a signal to noise ratio of 3, the detection limits were 0.75 nM for the tap water and 12.0 nmol kg^-1 for the soil. The method showed good recoveries and precision, 93.4% (RSD 1.5%, n = 3) for 100 mL of tap water spiked with 2.0 nmol and 81.3% (RSD 2.6%, n = 3) for 10 g of soil spiked with 0.80 nmol, suggesting that the imprinted stir bar can be successfully applied to the preconcentration of nicosulfuron in real samples.

[en] China Lead-based research reactor (CLEAR-I) is an integrative pool-type reactor, which uses liquid lead-bismuth alloy as coolant. Under earthquakes, the fluid-solid coupling effect caused by denser liquid metal could have significant impact on the structure of the main vessel. Based on two-way fluid-solid coupling, seismic response of the main vessel is calculated under ANSYS Workbench simulation environment. Through comparison of laminar model and K-ε turbulence model, the responses of structure to typical seismic acceleration excitation are analyzed, including deformation and equivalent stress. The results demonstrate that, considering seismic load and liquid metal, the seismic design of main vessel possesses sufficient functional and structural integrity. (authors)

[en] Highlights: • A bio-based flame retardant (IC) was synthesized via inclusion behavior. • Impact of IC on thermal stability and flame retardancy of EP was investigated. • Flame retardant mechanism of EP/IC was proposed. The aim of this work was to study the impact of inclusion complex (IC) between β-cyclodextrin (β-CD) and N, N′-diamyl-p-phenylphosphonicdiamide (P-MA) on the thermal stability and flame retardancy of epoxy resin (EP). IC was synthesized via inclusion process and characterized by ¹H nuclear magnetic resonance (NMR), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and scanning electron microscopy with X-ray microanalysis (SEM-EDS). ¹H NMR was used to identify the mole ratio of β-CD/P-MA in IC, shown that their mole ratio was 1:0.5. The inclusion complex (IC) was proposed to be a char promoter in EP via a combination of the properties of b-CD and P-MA during the combustion. By incorporating the IC, the flame retardancy of EP was expected to be improved. Thermal gravimetric analysis (TGA) showed that the thermal stability of IC was better than those of P-MA and physical mixture of β-CD and P-MA (PM). The impact of IC and PM on thermal stability and flame retardancy in EP were studied by TGA, limiting oxygen index (LOI), UL 94 and cone calorimeter tests. The heat and smoke releases of EP/IC were suppressed compared with those of EP and EP/PM.

[en] Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence

[en] In this work, flower-like hierarchical Nb₂O₅ microspheres self-assembled by nanorod with orthorhombic (T) phase were synthesized using hydrothermal method. The structure and morphology of T-Nb₂O₅ prepared is characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and morphology evolution mechanisms have been preliminarily proposed for the flower-like hierarchical structure. The electrochemical performances of T-Nb₂O₅ electrodes synthesized are detailed studied for use in LIBs and HSC devices. The T-Nb₂O₅ anode exhibits the reversible capacity of 191.42 mA h g⁻¹ at 0.05 A g⁻¹ and excellent rate performance (90.01 mA h g⁻¹ at 5A g⁻¹) in the voltage of 1.1–3.0 V (vs Li/Li⁺). The HSC using T-Nb₂O₅ anode and activated carbon cathode device delivers outstanding power density and energy density (8750 W kg⁻¹ and 40.25 W h kg⁻¹) with good stability in the voltage of 0.5–3.0 V. - Highlights: • Flower-like hierarchical Nb₂O₅ microspheres are synthesized via hydrothermal method. • The T-Nb₂O₅ anode exhibits the capacity of 191.42 mA h g⁻¹ at 0.05 A g⁻¹ • The discharge capacity of T-Nb₂O₅ anode is 90.01 mA h g⁻¹ at 5 A g⁻¹ • The T-Nb₂O₅//AC-based HSC system shows outstanding electrochemical performance.

[en] Highlights: •TGEV infection induced ROS accumulation. •ROS accumulation is involved in TGEV-induced mitochondrial integrity impairment. •ROS is associated with p53 activation and apoptosis occurrence in TGEV-infected cells. -- Abstract: Transmissible gastroenteritis virus (TGEV), an enteropathogenic coronavirus, causes severe lethal watery diarrhea and dehydration in piglets. Previous studies indicate that TGEV infection induces cell apoptosis in host cells. In this study, we investigated the roles and regulation of reactive oxygen species (ROS) in TGEV-activated apoptotic signaling. The results showed that TGEV infection induced ROS accumulation, whereas UV-irradiated TGEV did not promote ROS accumulation. In addition, TGEV infection lowered mitochondrial transmembrane potential in PK-15 cell line, which could be inhibited by ROS scavengers, pyrrolidinedithiocarbamic (PDTC) and N-acetyl-L-cysteine (NAC). Furthermore, the two scavengers significantly inhibited the activation of p38 MAPK and p53 and further blocked apoptosis occurrence through suppressing the TGEV-induced Bcl-2 reduction, Bax redistribution, cytochrome c release and caspase-3 activation. These results suggest that oxidative stress pathway might be a key element in TGEV-induced apoptosis and TGEV pathogenesis