Increased In Vitro Lysosomal Function in Oxidative Stress-Induced Cell Lines

Exposure of mammalian cells to oxidative stress alters lysosomal enzymes. Through cytochemical analysis of lysosomes with LysoTracker, we demonstrated that the number and fluorescent intensity of lysosome-like organelles in HeLa cells increased with exposure to hydrogen peroxide (H₂O₂), 6-hydroxydopamine (6-OHDA), and UVB irradiation. The lysosomes isolated from HeLa cells exposed to three oxidative stressors showed the enhanced antimicrobial activity against Escherichia coli. Further, when lysosomes that were isolated from HeLa cells exposed by oxidative stress were treated to normal HeLa cells, the viability of the HeLa cells was drastically reduced, suggesting increased in vitro lysosomal function (i.e., antimicrobial activity, apoptotic cell death). In addition, we also found that cathepsin B and D were implicated in increased in vitro lysosomal function when isolated from HeLa cells exposed by oxidative stress. Decrease in cathepsin B activity and increase in cathepsin D activity were observed in lysosomes isolated from HeLa cells after treatment with H₂O₂, 6-ODHA, or UVB, but cathepsin B and D were not the sole factors to induce cell death by in vitro lysosomal function. Therefore, these studies suggest a new approach to use lysosomes as antimicrobial agents and as new materials for treating cancer cell lines.     

Syntheses and single-crystal structures of CsTh(MoO4)2Cl and Na4Th(WO4)4

Colorless crystals of CsTh(MoO₄)₂Cl and Na₄Th(WO₄)₄ have been synthesized at 993 K by the solid-state reactions of ThO₂, MoO₃, CsCl, and ThCl₄ with Na₂WO₄. Both compounds have been characterized by the single-crystal X-ray diffraction. The structure of CsTh(MoO₄)₂Cl is orthorhombic, consisting of two adjacent [Th(MoO₄)₂] layers separated by an ionic CsCl sublattice. It can be considered as an insertion compound of Th(MoO₄)₂ and reformulated as Th(MoO₄)₂·CsCl. The Th atom coordinates to seven monodentate MoO₄ tetrahedra and one Cl atom in a highly distorted square antiprism. Na₄Th(WO₄)₄ adopts a scheelite superlattice structure. The three-dimensional framework of Na₄Th(WO₄)₄ is constructed from corner-sharing ThO₈ square antiprisms and WO₄ tetrahedra. The space within the channels is filled by six-coordinate Na ions. Crystal data: CsTh(MoO₄)₂Cl, monoclinic, P2₁/c, Z=4, a=10.170(1) Å, b=10.030(1) Å, c=9.649(1) Å, β=95.671(2)°, V=979.5(2) Å³, R(F)=2.65% for I>2σ(I); Na₄Th(WO₄)₄, tetragonal, I4₁/a, Z=4, a=11.437(1) Å, c=11.833(2) Å, V=1547.7(4) Å³, R(F)=3.02% for I>2σ(I).     

变系数耗散波动方程的能量衰减估计

研究了在（0,∞）×Rⁿ上,变系数耗散波动方程的能量在外区域上的衰减估计,得到：若初值{u₀,u₁}属于能量空间且具有紧支集,则在Rⁿ上存在一个外区域X_m,使得对任意t ≥ 0和m>0,有进一步,若u₀+u₁=0,还可以得到∫_Xm|u|²dx ≤ C（1+t）^-m,t ≥ 0.     

Ring‐Opening Polymerization of ε‐Caprolactone by Poly(ethylene glycol) by an Activated Monomer Mechanism

Summary: The polymerization of ε‐caprolactone (CL) in the presence of HCl · Et₂O by an activated monomer mechanism was performed to synthesize diblock or triblock copolymers composed of poly(ethylene glycol) (PEG) and poly(ε‐caprolactone) (PCL). The obtained PCLs had molecular weights close to the theoretical values calculated from the CL to PEG molar ratios and exibited monomodal GPC curves. We successfully prepared PEG and PCL block copolymers by a metal‐free method.

The non‐metal catalyzed living ring‐opening polymerisation of ε‐caprolactone by PEG.     

The first excited states of 9Be and 9B

It is found here that the 1/2⁺ first excited state of ⁹Be is a virtual state with the energy of −23.5 KeV. The line shape for the excitation of the state is approximated with a simple analytic form based on the effective range expansion. The partner in ⁹B of this state is found to be a resonance with a maximum in the peak at about 1.1 MeV, FWHM of 1.5 MeV, and complex energy of 0.6 −i0.75 MeV. The line shape for its excitation is calculated in terms of the p−⁸Be phase shift. The phase shifts are obtained from N−⁸Be effective potentials deduced from the data on the photodisintegration of ⁹Be. A possibility for direct extraction of the energy of the resonant state from experimental data is also discussed, and an expression for a residue at a virtual state pole in terms of a quadrature taken over the virtual state eigenfunction is given. Received: 23 March 1998 / Revised version: 3 September 1998     

Molecular Design of Calixarene,Part 4, Synthesis of Novel Double‐Armed p‐(tert‐Butyl)calix[4]arene‐Derived Amides and Their Lead(II)(Pb2+)‐Selective‐Electrode Properties

A series of novel double‐armed p‐(tert‐butyl)calix[4]arenes, carrying benzoylamido, 4‐nitrobenzoylamido, isonicotinamido, α‐naphthamido, acetamido, propionamido, or butyramido groups (see 2 – 8 , resp.) were synthesized in 80 – 86% yield by the reaction of the lower‐rim 1,3‐bis(aminoethoxy)‐substituted calix[4]arenediol 1 with the corresponding acylating agents. Their structures were established by elemental analysis, mass, IR, UV, and ¹H‐NMR spectroscopy. Ion‐selective electrodes (ISEs) for Pb²⁺, carrying 2 – 8 in a PVC membrane as neutral ionophore, were prepared, and their selectivity coefficients for Pb²⁺ (K) were determined against other heavy‐metal ions, alkali and alkaline earth metal ions, and ammonium ions by means of the separate‐solution method. The results obtained indicated that the electrodes based on the calix[4]arene‐derived amides 2 – 8 as the neutral ionophores were all Pb²⁺ selective and exhibited almost theoretical Nernstian slopes, except for 3 and 4 . Typically, the Pb²⁺‐selective electrode based on 6 – 8 exhibited almost Nernstian slopes for Pb²⁺ over a relatively wide concentration range and had a fast response time as well as a long lifetime, although the silver ion interfered strongly. These ISEs based on 6 – 8 showed a relatively good Pb²⁺ selectivity against most of the interfering cations examined, except for Ag⁺. The effect of the side‐arm functions of calix[4]arene derivatives 2 – 8 on the Nernstian slopes and on the selectivity coefficients for Pb²⁺ obtained with the Pb²⁺ ISEs based on 2 – 8 is discussed.     

Travel Characteristics Analysis and Traffic Prediction Modeling Based on Online Car-Hailing Operational Data Sets

Smart transportation is an important part of smart urban areas, and travel characteristics analysis and traffic prediction modeling are the two key technical measures of building smart transportation systems. Although online car-hailing has developed rapidly and has a large number of users, most of the studies on travel characteristics do not focus on online car-hailing, but instead on taxis, buses, metros, and other traditional means of transportation. The traditional univariate variable hybrid time series traffic prediction model based on the autoregressive integrated moving average (ARIMA) ignores other explanatory variables. To fill the research gap on online car-hailing travel characteristics analysis and overcome the shortcomings of the univariate variable hybrid time series traffic prediction model based on ARIMA, based on online car-hailing operational data sets, we analyzed the online car-hailing travel characteristics from multiple dimensions, such as district, time, traffic jams, weather, air quality, and temperature. A traffic prediction method suitable for multivariate variables hybrid time series modeling is proposed in this paper, which uses the maximal information coefficient (MIC) to perform feature selection, and fuses autoregressive integrated moving average with explanatory variable (ARIMAX) and long short-term memory (LSTM) for data regression. The effectiveness of the proposed multivariate variables hybrid time series traffic prediction model was verified on the online car-hailing operational data sets.     

ChemInform Abstract: Mixed‐Valent Neptunium(IV/V) Compound with Cation—Cation‐Bound Six‐Membered Neptunyl Rings.

Na_xNp^IV(Np^VO₂)₆ (OH)_1+xCl₉(H₂O)_8‐x (0 < x ≤ 1) is synthesized by evaporation of a neptunium(V) acidic (HCl) stock solution over several months to complete dryness.