Ischaemic post-conditioning protects lung from ischaemia-reperfusion injury by up-regulation of haeme oxygenase-1

Objective: The emergence of ischaemic post-conditioning (IPO) provides a potential method for experimentally and clinically attenuating various types of organ injuries. There has been little work, however, examining its effects in the setting of lung ischaemia reperfusion (IR). The stress protein, haeme oxygenase-1 (HO-1), has been found to exert a potent, protective role in a variety of lung injury models. In this study, we hypothesised that the induction of HO-1 by IPO plays a protective role against the deleterious effects of IR in the lung. Methods: Anaesthetised and mechanically ventilated adult Sprague-Dawley rats were randomly assigned to one of the following groups (n = 8 each): the sham-operated control group, the IR group (40 min of left-lung ischaemia and 105 min of reperfusion), the IPO group (three successive cycles of 30-s reperfusion per 30-s occlusion before restoring full perfusion) and the ZnPPIX + IPO group (ZnPPIX, an inhibitor of HO-1, was injected intra-peritoneally at 20 mg kg -1 24 h prior to the experiment and the rest of the procedures were similar to that of the IPO group). Lung injury was assessed by arterial blood gas analysis, wet-to-dry lung weight ratio and tissue histological changes. The extent of lipid peroxidation was determined by measuring plasma levels of malondialdehyde (MDA) production. Expression of HO-1 was determined by immunohistochemistry. Results: Lung IR resulted in a significant reduction of PaO 2 (data in IR, P < 0.05 vs. data in sham) and increase of lung wet-to-dry weight ratio, accompanied with increased MDA production and severe lung pathological morphological changes as well as a compensatory increase in HO-1 protein expression, as compared with sham (All P < 0.05). IPO markedly attenuated all the above pathological changes seen in the IR group and further increased HO-1 expression. Treatment with ZnPPIX abolished all the protective effects of post-conditioning. Conclusion: It may be concluded that IPO protects IR-induced lung injury via induction of HO-1. © 2009 Elsevier Ltd. All rights reserved.postprin

Wavelength-multiplexed duplex transceiver based on III-V/Si hybrid integration for off-chip and on-chip optical interconnects

A six-channel wavelength-division-multiplexed optical transceiver with a compact footprint of 1.5 x 0.65 mm(2) for off-chip and on-chip interconnects is demonstrated on a single silicon-on-insulator chip. An arrayed waveguide grating is used as the (de)multiplexer, and III-V electroabsorption sections fabricated by hybrid integration technology are used as both modulators and detectors, which also enable duplex links. The 30-Gb/s capacity for each of the six wavelength channels for the off-chip transceiver is demonstrated. For the on-chip interconnect, an electrical-to-electrical 3-dB bandwidth of 13 GHz and a data rate of 30 Gb/s per wavelength are achieved

Psychological drivers of hotel guests’ energy‐saving behaviours—empirical research based on the extended theory of planned behaviour

The hospitality industry is an important energy consumer and carbon emitter. Behaviour-driven energy conservation is a strategy with great promise to strengthen the energy efficiency of hotel buildings. The aim of this study is to explore the driving psychological factors of hotel guests’ energy-saving intentions and behaviours. This paper constructs two extensions of the theory of planned behaviour (TPB) with personal norms, past behaviours, and self-determined motivation to explain the guests’ energy-saving behaviour in hotel buildings. This research compares the explanatory power of the original TPB and two extensions with structural equation modelling. The analysis is based on 530 valid, self-reported data from 827 surveyed hotel guests in Shanghai. The analysis suggests that the extended model gains greater explanatory power in predicting the behaviour patterns by employing the above three additional factors. In addition, self-determined motivation presents a more significant impact than other more developed TPB predictors, such as intention and perceived behaviour control. Aside from that, past behaviour replaces attitude as the most critical predictor of hotel energy-saving intention in the extended models. In addition to the existing interventions in office and residential buildings, the research highlights the role of self-determination in hotel energy conservation and further emphasises the long-term benefit of encouraging pro-environmental behaviours in hotel guests. The findings expand the existing research on pro-environmental behaviours and will contribute to energy-saving behaviour intervention in hotel buildings and policy formulations for sustainable hotel operation and maintenance.</jats:p

AMS Radiocarbon Dating of Tianma-Qucun Site in Shanxi, China

Tianma-Qucun is the biggest site of Western Zhou Dynasty discovered in Shanxi Province, China. It has been recognized as the early capital of Jin, a vassal state of Western Zhou. The territories were granted to the first Marquis of Jin with the title in the early days of Western Zhou. Bone sample series from the site were radiocarbon-dated by accelerator mass spectrometry (AMS) and calibrated with the Oxford calibration program OxCal 3.5. Bayesian analysis of the calibrated ages shows that the earliest residents of the Western Zhou came to Tianma-Qucun area in 1020-940 BC and the lower boundary of the Western Zhou is 796-754 BC, which corresponds well to the historical record 770 BC.Geochemistry &amp; GeophysicsSCI(E)CPCI-S(ISTP)

Low driving voltage band-filling-based III-V-on-silicon electroabsorption modulator

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Preparation of Pectin–ZnO Nanocomposite

Pectin–ZnO nanocomposite was prepared in the aqueous solution condition at room temperature. The Fourier transform infrared, X-ray diffraction, and transmission electron microscope (TEM) measurements confirmed the nanoscaled structure of pectin–ZnO composite. According to the TEM observation, the average composite granules size was about 150 nm and the embedded ZnO nanoparticles were uniform with an average diameter of 70 nm

Improvements and Applications of AMS Radiocarbon Measurement at Peking University

AMS radiocarbon measurements were started at Peking University in 1992 with a modified HICONEX 834 ion source. Some archaeological samples were measured at a sensitivity of 10(-14) with ca. 1.7% precision for modern samples. We have made many improvements in our first two years of operation: a high-intensity Cs sputtering ion source was installed; the graphite sample preparation technique was investigated; and the system stability has been improved. The blank sample background is currently ca. 0.006 MC and a precision within 1% can be reached for modern samples. Geological, archaeological, environmental and biomedical samples can be measured routinely. We present some typical applications.Geochemistry &amp; GeophysicsSCI(E)

Axisymmetric compressive buckling of multi-walled carbon nanotubes under different boundary conditions

The paper studies the axisymmetric compressive buckling behavior of multi-walled carbon nanotubes (MWNTs) under different boundary conditions based on continuum mechanics model. A buckling condition is derived for determining the critical buckling load and associated buckling mode of MWNTs, and numerical results are worked out for MWNTs with different aspect ratios under fixed and simply supported boundary conditions. It is shown that the critical buckling load of MWNTs is insensitive to boundary conditions, except for nanotubes with smaller radii and very small aspect ratio. The associated buckling modes for different layers of MWNTs are in-phase, and the buckling displacement ratios for different layers are independent of the boundary conditions and the length of MWNTs. Moreover, for simply supported boundary conditions, the critical buckling load is compared with the corresponding one for axial compressive buckling, which indicates that the critical buckling load for axial compressive buckling can be well approximated by the corresponding one for axisymmetric compressive buckling. In particular, for axial compressive buckling of double-walled carbon nanotubes, an analytical expression is given for approximating the critical buckling load. The present investigation may be of some help in further understanding the mechanical properties of MWNTs

An experimental investigation into the dimensional error of powder-binder three-dimensional printing

This paper is an experimental investigation into the dimensional error of the rapid prototyping additive process of powder-binder three-dimensional printing. Ten replicates of a purpose-designed part were produced using a three-dimensional printer, and measurements of the internal and external features of all surfaces were made using a general purpose coordinate measuring machine. The results reveal that the bases of all replicates (nominally flat) have a concave curvature, producing a flatness error of the primary datum. This is in contrast to findings regarding other three-dimensional printing processes, widely reported in the literature, where a convex curvature was observed. All external surfaces investigated in this study showed positive deviation from nominal values, especially in the z-axis. The z-axis error consisted of a consistent positive cumulative error and a different constant error in different replicates. By compensating for datum surface error, the average total height error of the test parts can be reduced by 25.52 %. All the dimensional errors are hypothesised to be explained by expansion and the subsequent distortion caused by layer interaction during and after the printing process