[en] Based on the basic principle of the function of the parrallel plate spark chamber, two formulae relating the clearing field to the detection efficiency and sentive time are derived. The validity of these formulae are tested by experiment and shown that they are useful in the choice of the clearing field properly for experiments

[en] Objective: To study the effect of fluvastatin on changes of serum Hcy, IL-6 and IL-8 levels in patients with coronary heart disease. Methods: 88 patients with CHD were random in divided into fluvastatin-treated group(35 cases) and conventional therapy group (53 cases). In addition, 50 healthy persons served as control group. Serum IL-6, IL-8(with RIA) and Hcy (with ELISA) levels were measured both before and after treatment for 2 months with fluvastatin in these CHD patients as well as in controls. Results: (1) Before treatment, the levels of serum Hcy, IL-6, IL-8 were remarkably higher in the patients with CHD than those in controls (P < 0.01). (2) After treatment, the levels of serum Hcy, IL-6, IL-8 in patients with fluvastatin-treated group decreased significantly (P < 0.01), but the levels were not much changed in the conventional therapy group. Conclusion: Fluvastatin have anti-infammatory and therapeutic effect on the patients with CHD. (authors)

[en] In this project, a Blumlein line with a folded parallel-plates configuration using Kapton film as dielectrics was investigated. The characteristic parameters of this Blumlein line were analysed theoretically. The electric field distributions under different inner radii of the folded part were simulated. The output waveforms on the match load were also simulated by means of an equivalent electric circuit. According to the results of the theoretecal analysis and simulation, a Blumlein line with the folded parallel-plates configuration with an output voltage of 500 kV, a pulse duration of 100 ns, and a characteristic impedance of 4.773 ω was designed and manufactured. The experimental results properly demonstrated the wave transmitting process in the Blumlein line, and provided the voltage waveform of 500 kV and the current waveform of 50 kA with a pulse duration of 150 ns. Some engineering problems such as the edge electric breakdown and measuring precision by a resistance divider were revealed, which must be solved in future work to produce a more compact transmission line.

[en] Highlights: • Investigation on the structural characteristics, physicochemical properties and analytical method of NODs. • Occurrence of NODs around the world: Sources, poisoning and distribution. • The biosynthesis, regulation and degradation of NODs are studied. • A potential toxicity of NODs: In vitro and in vivo studies. • Evaluation of the toxicokinetics of NODs including cellular uptake, detoxification and toxicity mechanism. The occurrence of cyanobacterial toxins is being increasingly reported. Nodularins (NODs) are one of the cyanotoxins group mainly produced by Nodularia spumigena throughout the world. NODs may exert adverse effects on animal and human health, and NOD-R variant is the most widely investigated. However, research focused on them is still limited. In order to understand the realistic risk well, the aim of this review is to compile the available information in the scientific literature regarding NODs, including their sources, distribution, structural characteristics, physicochemical properties, biosynthesis and degradation, adverse effects in vitro and vivo, and toxicokinetics. More data is urgently needed to integrate the cumulative or synergistic effects of NODs on different species and various cells to better understand, anticipate and aggressively manage their potential toxicity after both short- and long-term exposure in ecosystem, and to minimize or prevent the adverse effects on human health, environment and the economy.

[en] In this work, the formation and characterization of nano-sized grains on the modified surfaces of GCr15 and H13 steels have been investigated. The material was processed by pulsed laser surface melting (LSM) under different depths of de-ionized water. The microstructures and phases of the melted zones were examined by x-ray diffraction, environmental field emission scanning electron microscopy and high resolution transmission electron microscopy. The results indicate that LSM under water can successfully fabricate nano-scaled grains on the surfaces of steel, due to the rapid solidification and crystallization by heterogeneous nucleation. The elemental segregation of chromium and activated heterogeneous nucleation mechanism of austenite in liquid metal play a key role in the formation of nano-sized grains at high cooling rates. This one-step technique provides us a new way to prepare uniform nano-scaled grains, and is of great importance for further understanding the growth of nano-materials under extreme conditions.

[en] This paper focused on the influence of yttrium (Y) addition and powder size (diameter) on the oxide film and powder ignition temperature of AZ91D alloy. Y addition in the alloy fell into 6 categories, namely 0 wt.%, 0,15 wt.%, 0.28 wt.%, 0.45 wt.%, 0.60 wt.% and 1.0 wt.%. The powders of 58 μm, 75 μm, 106 μm, 120 μm, 150 μm, 200 μm and 270 μm in diameter were used for analysis of the influence of powder size on oxidation resistance of alloy powders. During oxidation test, powder size had limited influence on the ignition temperature of the alloy powders. The specific area and inter-space of the powders showed opposite effect on the ignition temperature of the alloy. With increasing Y addition, the tightness of oxide film increased, thus ignition temperature increased, obtaining peak magnitude at 0.28 wt.% Y addition. And then, it began to decrease with further increasing Y addition to 1.0 wt.%.

[en] The grain-refining behavior of TiB₂ particles was investigated by the method of adding Al-4B master alloy into the melt of electrolytic low-titanium aluminum (ELTA). The results indicate that TiB₂ particles will be formed when the Al-4B master alloy is added into the melt of ELTA. These TiB₂ particles are produced by in situ technology, thus their surface properties are preserved and do not alter. At the bottom of the melt, the TiB₂ particles are pushed to the grain boundaries because of the absence of enough titanium atoms, which indicates that TiB₂ particles alone are not potent nuclei of α-Al. Though some TiB₂ particles settle down at the bottom, there are still numbers of fine TiB₂ particles suspended. These TiB₂ particles, together with the titanium atoms left, will form much more heterogeneous nucleation sites during the solidification of the melt, resulting in the grain-refining efficiency of the ELTA with Al-4B addition being improved obviously. To investigate the grain-refining mechanism of aluminum, this method has its advantages in comparison with that of adding synthetic TiB₂ particles into the melt of aluminum

[en] This paper focused on the effect of cooling rate on oxidation resistance and ignition temperature (T_i) of AM50 alloy. Y addition of 0.0 wt%, 0.15 wt%, 0.28 wt%, 0.45 wt% and 1.00 wt%, respectively was added to the AM50 alloy. The result showed that the oxidation resistance was directly affected by the microstructure. Rapid solidification (RS) had a positive effect on improving the oxidation resistance. It is noticeable that no Al₂Y intermetallic compound was found in the microstructure after RS. Elemental Y dissolved in the solid solution increased with increasing Y addition after RS. It is confirmed that Y addition dissolved in the solid solution and phase distribution were key factors for improving the oxidation resistance

[en] Highlights: • Polymer micro-structure affected NPs preparation, and NPs-size selection could through by affecting cell proliferation. • That how to select material and NPs size on drug delivery system is significant for tumor diagnosis and treatment. • The paper told us how to choose suitable polymer and NPs size to perfect design of drug delivery system. - Abstract: In this paper, the micro-structure of amphiphilic copolymer Polylactic acid-Polyethylene glycol-Folate (PLA-PEG-FA) was studied firstly by a differential scanning calorimetry (DSC). During the process of nanoparticles (NPs) preparation, we found good inter-structure consistency of polymer was the precondition for forming into stable NPs, and those with micro-phase separation structure were prepared of NPs within limits. Hemolytic test and CCK-8 assay results demonstrated the biotoxicity of both NPs and whose leaching liquor was far below related toxicity standards. Two kinds of cell, human breast cancer cell line (MCF-7) and human umbilical vein endothelial cells (EC), showed different manners in test of NPs size-cell proliferation relationship, respectively. Monitored by a nuclear magnetic resonance (NMR) and a gel permeation chromatography (GPC), the degradation behavior of NPs in aqueous solution indicated amide bond break more difficultly than ester bond, and FA classic proton peak disappeared in the third week, meanwhile lactic acid (LA) unit number became 25% of the initial. Finally the NPs was completely degraded in the eighth week. In the whole process, NPs underwent a change from compact to loose state. We hope these results will benefit to improve design of drug delivery system in nanomedicine, which could offer the selection rule for amphiphilic polymer NPs on material and size.

[en] The influence of various cerium (Ce) additions and starting temperature on the resistance to oxidation of AM50 alloy prepared by rapid solidification (RS, RS-AM50 alloy) has been investigated. The Ce addition has two opposite effects on the oxide scale. To the RS-alloy, the beneficial effect outweighs the detrimental one. However, when the alloy was prepared by slow solidification at the normal cooling rate (SS, SS-AM50 alloy), the detrimental effect was dominant. The improvement of oxide scale is closely related to the adherence of metal/oxide and tightness of oxide scale of the alloy. In addition, the reaction rate at the surface increased with starting temperature, which finally results in the formation of a protective oxide scale.