篇首语

本期的专题源于2007年北京大学景观设计大会,众多中外景观设计师和学者参加了此次会议,会议上不乏精彩的观点和激烈的争论,不同的文化背景并没有成为景观对话与交流的障碍,这是一次中西方景观的对话。在对会议内容进行整理报道的基础之上,我们增加了网络对话,包括“境外景观事务所在中国”和“杂志互动”两个部分的内容。“境外景观事务所在中国”选择了四家在中国有设计项目的境外设计公司做了访谈,     

Dried Blood Spots as Matrix for Evaluation of Valproate Levels and the Immediate and Delayed Metabolomic Changes Induced by Single Valproate Dose Treatment

The immediate and delayed metabolic changes in rats treated with valproate (VPA), a drug used for the treatment of epilepsy, were profiled. An established approach using dried blood spots (DBS) as sample matrices for gas chromatography/mass spectrometry-based metabolomics profiling was modified using double solvents in the extraction of analytes. With the modified method, some of the previously undetectable metabolites were recovered and subtle differences in the metabolic changes upon exposure to a single dose of VPA between males and female rats were identified. In male rats, changes in 2-hydroxybutyric acid, pipecolic acid, tetratriacontane and stearic acid were found between the control and treatment groups at various time points from 2.5 h up to 24 h. In contrast, such differences were not observed in female rats, which could be caused by the vast inter-individual variations in metabolite levels within the female group. Based on the measured DBS drug concentrations, clearance and apparent volume of distribution of VPA were estimated and the values were found to be comparable to those estimated previously from full blood drug concentrations. The current study indicated that DBS is a powerful tool to monitor drug levels and metabolic changes in response to drug treatment.     

Cryogenic Exfoliation of 2D Stanene Nanosheets for Cancer Theranostics

Stanene(Sn)-based materials have been extensively applied in industrial production and daily life,but their potential biomedi-cal application remains largely un...     

智能网与Internet互通的模型与实现

介绍了智能网（IN）与In-ternet互通（PINT）的系统原理，以及PINT和SPIRITS等两类互通业务的网络结构，给出了智能网与Inter-net互通的模型。讨论了智能网与In-ternet互通的实现，并给出了一个PINT业务实例-点击拨号业务。     

Macrophage Migration Inhibitory Factor (MIF) as a Stress Molecule in Renal Inflammation

Renal inflammation is an initial pathological process during progressive renal injury regardless of the initial cause. Macrophage migration inhibitory factor (MIF) is a truly proinflammatory stress mediator that is highly expressed in a variety of both inflammatory cells and intrinsic kidney cells. MIF is released from the diseased kidney immediately upon stimulation to trigger renal inflammation by activating macrophages and T cells, and promoting the production of proinflammatory cytokines, chemokines, and stress molecules via signaling pathways involving the CD74/CD44 and chemokine receptors CXCR2, CXCR4, and CXCR7 signaling. In addition, MIF can function as a stress molecule to counter-regulate the immunosuppressive effect of glucocorticoid in renal inflammation. Given the critical position of MIF in the upstream inflammatory cascade, this review focuses on the regulatory role and molecular mechanisms of MIF in kidney diseases. The therapeutic potential of targeting MIF signaling to treat kidney diseases is also discussed.     

珠海发电厂电动给水泵电动机保护动作分析

珠海发电厂1号机1号电动给水泵启动中综合保护继电器保护动作,跳开电动给水泵电源开关,马达端盖出风口有青黑色烟气冒出.根据综合保护继电器记录数据,利用矢量分析法,结合继电保护及电力系统稳态、暂态理论知识,在最短时间内分析出电动机发生了B相绕组匝间短路,为确定电动机故障点提供了理论支持,确保了故障电动机的及时维修,并在电动给水泵进行解体后,验证了理论分析的正确性.     

NiCuZn ferrite flakes prepared using a sol-gel bubble method and its magnetic properties

Ni_0.23Cu_0.11Zn_0.66Fe₂O₄ ferrite flakes, with thickness of about 8 μm and average diameter of 20-35 μm, were prepared using a sol-gel bubble method. Morphology, phase evolution, static and dynamic magnetic properties of the flakes and their composites were studied. Magnetic measurements showed that easy magnetization direction of the flaky filler composite was parallel to its sample plane. Composites made of silicone resins and flakes had higher complex permeability, which can be attributed to the reduction in demagnetization factor due to their flaky shapes. This sol-gel bubble method should be also applicable to fabricating flakes of other multi-component oxides.     

An innovative method to perform maskless plain waterjet milling for pocket generation: a case study in Ti-based superalloys

This paper presents an innovative methodology/jet path on which plain waterjet (PWJ) can generate pockets of good dimensional/geometrical definition (minimised under/over-erosion) while the proposed method leads to the avoidance of grit embedment on the target workpiece and the elimination of extra cost and time related to the use of mask.The novelty of the paper relies on the proposal of jet-path strategy that minimises the variations in jet dwell time by providing “continuous” relative movement during the jet-part interaction (through minimisation of accelerations/decelerations of the machine head) and by removing a controlled amount of material in a series of layers using special techniques. The proposed method is powerful in its approach from which it ensures (quasi)equal exposure time for each zone of material over which the jet passes, so that the jet path is “totally contained” within the form to be generated; hence, no masking is necessary to define the contour/shape.This approach has been employed for generating pockets on two Ti-based superalloys commonly used in aerospace industries, followed by dimensional, geometrical and surface quality analysis. The results proved that this approach can produce milled surfaces of straightness of the pocket bottom (<200 μm), tolerance on depth of cut per layer (<20 μm), tolerance on the radii at the bottom of the pockets (<100 μm), surface roughness (Ra=4–14 μm) and waviness (Wa=10–13 μm) characteristics in conditions of high surface integrity (no cracks, contaminations, etc.).