Integrating spatial and temporal approaches for explaining bicycle crashes in high-risk areas in Antwerp (Belgium)

The majority of bicycle crash studies aim at determining risk factors and estimating crash risks by employing statistics. Accordingly, the goal of this paper is to evaluate bicycle-motor vehicle crashes by using spatial and temporal approaches to statistical data. The spatial approach (a weighted kernel density estimation approach) preliminarily estimates crash risks at the macro level, thereby avoiding the expensive work of collecting traffic counts; meanwhile, the temporal approach (negative binomial regression approach) focuses on crash data that occurred on urban arterials and includes traffic exposure at the micro level. The crash risk and risk factors of arterial roads associated with bicycle facilities and road environments were assessed using a database built from field surveys and five government agencies. This study analysed 4120 geocoded bicycle crashes in the city of Antwerp (CA, Belgium). The data sets covered five years (2014 to 2018), including all bicycle-motorized vehicle (BMV) crashes from police reports. Urban arterials were highlighted as high-risk areas through the spatial approach. This was as expected given that, due to heavy traffic and limited road space, bicycle facilities on arterial roads face many design problems. Through spatial and temporal approaches, the environmental characteristics of bicycle crashes on arterial roads were analysed at the micro level. Finally, this paper provides an insight that can be used by both the geography and transport fields to improve cycling safety on urban arterial roads

Stable and Efficient Nanofilm Pure Evaporation on Nanopillar Surfaces

Molecular dynamics simulations were conducted to systematically investigate how to maintain and enhance nanofilm pure evaporation on nanopillar surfaces. First, the dynamics of the evaporation meniscus and the onset and evolution of nanobubbles on nanopillar surfaces were characterized. The meniscus can be pinned at the top surface of the nanopillars during evaporation for perfectly wetting fluid. The curvature of the meniscus close to nanopillars varies dramatically. Nanobubbles do not originate from the solid surface, where there is an ultrathin nonevaporation film due to strong solid–fluid interaction, but originate and evolve from the corner of nanopillars, where there is a quick increase in potential energy of the fluid. Second, according to a parametric study, the smaller pitch between nanopillars (P) and larger diameter of nanopillars (D) are found to enhance evaporation but also raise the possibility of boiling, whereas the smaller height of nanopillars (H) is found to enhance evaporation and suppress boiling. Finally, it is revealed that the nanofilm thickness should be maintained beyond a threshold, which is 20 Å in this work, to avoid the suppression effect of disjoining pressure on evaporation. Moreover, it is revealed that whether the evaporative heat transfer is enhanced on the nanopillar surface compared with the smooth surface is also affected by the nanofilm thickness. The value of nanofilm thickness should be determined by the competition between the suppression effect on evaporation due to the decrease in the volume of supplied fluid and the existence of capillary pressure and the enhancement effect on evaporation due to the increase in the heating area. Our work serves as the guidelines to achieve stable and efficient nanofilm pure evaporative heat transfer on nanopillar surfaces

Multidimensional performance optimization of conducting polymer-based supercapacitor electrodes

Supercapacitors based on conducting polymers promise to bridge the gap between the high power densities of carbon-based double-layer capacitors and the high energy densities of batteries. While much work has focused on improving the specific capacitance of these materials, emerging applications also demand competitive performance with regards to a variety of other criteria, including long-term cycling stability, mechanical robustness, and scalability of fabrication. There is no consolidated summary in the literature, however, of the specific strategies used to target these individual metrics as well as the tradeoffs that exist between them. Herein, we review the most recent progress in engineering high performance conducting polymer-based supercapacitor electrodes, emphasizing the successful techniques for polymer synthesis, nanostructuring, and compositing with carbon or metal oxides which have been used to optimize each of the most important supercapacitor performance metrics.This work was funded by the European Research Council (ERC) grant to S.K.S., EMATTER (# 280078). K.D.F. acknowledges support from the Winston Churchill Foundation of the United States. T.W. thanks the China Scholarship Council (CSC) for funding and the Engineering and Physical Sciences Research Council of the UK (EPSRC) Centre for Doctoral Training in Sensor Technologies and Applications (grant number: EP/L015889/1) for support

空间感知的碳纳米管模型生成

碳纳米管在纳米新材料和新一代半导体器件的研制中有广泛应用。在进行设计时,需要搜索与现有碳纳米管体积差最小的替换结构用以生成尺寸相近的新器件。直接搜索体积相近的碳纳米管结构,所需的时间复杂度是O(n2)。在对搜索空间进行大幅缩简后,提出一种时间复杂度为O(n)的快速搜索方法。在多个应用实例中,本算法的有效性得到了较好的验证。published_or_final_versio

Extracts From New Zealand Undaria Pinnatifida Containing Fucoxanthin As Potential Functional Biomaterials Against Cancer in Vitro

This study tested extracts from New Zealand seaweed Undaria pinnatifida containing fucoxanthin, in parallel with pure fucoxanthin, in nine human cancer cell lines, for anticancer activity. Growth inhibition effects of extracts from Undaria pinnatifida were found in all types of cancer cell lines in dose- and time- dependent manners. Cytotoxicity of fucoxanthin in three human non-cancer cell lines was also tested. Compared with pure fucoxanthin, our extracts containing low level of fucoxanthin were found to be more effective in inhibiting the growth of lung carcinoma, colon adenocarcinoma and neuroblastoma. Our results suggest that fucoxanthin is a functional biomaterial that may be used as a chemopreventive phytochemical or in combination chemotherapy. Furthermore, we show for the first time that some unknown compounds with potential selective anti-cancer effects may exist in extracts of New Zealand Undaria pinnatifida, and New Zealand Undaria pinnatifida could be used as a source for either functional biomaterial extraction or production of functional food

Electrochemical degradation of 4-chlorophenol at nickel-antimony doped tin oxide electrode

The effectiveness of a novel nickel-antimony doped tin oxide electrode for electrochemical degradation of organic pollutants was investigated using 4-chlorophenol (4-CP) as a model toxic organic. The experimental results demonstrate that the optimal Ni content was at Ni:Sn = 1:500 in atomic ratio in the precursor coating solution, whereas the Sb:Sn ratio was set at 8:500. Using the electrode prepared with the optimal Ni doping ratio for 4-CP degradation, the charge-based efficiencies were up to 89 μg C -1 for 4-CP destruction and 15 μg C -1 for TOC removal, which were considerably higher than the efficiencies observed for other electrodes. It is suggested that the enhancement of the electrode for electrochemical oxidation of organics could be attributed to the production of hydroxyl radicals in anodic water electrolysis. © 2006 Elsevier Ltd. All rights reserved.postprin

Gestational surrogacy in Australia 2004-2011: Treatment, pregnancy and birth outcomes

© 2016 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists. Background Information on gestational surrogacy arrangement and outcomes is limited in Australia. Aims This national population study investigates the epidemiology of gestational surrogacy arrangement in Australia: treatment procedures, pregnancy and birth outcomes. Materials and methods A retrospective study was conducted of 169 intended parents cycles and 388 gestational carrier cycles in Australia in 2004-2011. Demographics were compared between intended parents and gestational carrier cycles. Pregnancy and birth outcomes were compared by number of embryos transferred. Results Over half (54%) intended parents cycles were in women aged <35 years compared to 38% of gestational carrier cycles. About 77% of intended parents cycles were of nulliparous women compared to 29% of gestational carrier cycles. Of the 360 embryo transfer cycles, 91% had cryopreserved embryos transferred and 69% were single-embryo transfer (SET) cycles. The rates of clinical pregnancy and live delivery were 26% and 19%, respectively. There were no differences in rates of clinical pregnancy and live delivery between SET cycles (27% and 19%) and double-embryo transfer (DET) cycles (25% and 19%). Five of 22 deliveries following DET were twin deliveries compared to none of 48 deliveries following SET. There were 73 liveborn babies following gestational surrogacy treatment, including 9 liveborn twins. Of these, 22% (16) were preterm and 14% (10) were low birthweight. Preterm birth was 13% for liveborn babies following SET, lower than the 31% or liveborn babies following DET. Conclusions To avoid adverse outcomes for both carriers and babies, SET should be advocated in all gestational surrogacy arrangements

CXCL12/CXCR4 axis: an emerging neuromodulator in pathological pain

The roles of chemokine C-X-C motif ligand 12 (CXCL12) and its receptor chemokine C-X-C motif receptor 4 (CXCR4) reveal this chemokine axis as an emerging neuromodulator in the nervous system. In the peripheral and central nervous systems, both CXCL12 and CXCR4 are expressed in various kinds of nociceptive structures, and CXCL12/CXCR4 axis possesses pronociceptive property. Recent studies have demonstrated its critical roles in the development and maintenance of pathological pain, and both neuronal and glial mechanisms are involved in this CXCL12/CXCR4 axis-mediated pain processing. In this review, we summarize the recent development of the roles and mechanisms of CXCL12/CXCR4 axis in the pathogenesis of chronic pain by sciatic nerve injury, human immunodeficiency virus-associated sensory neuropathy, diabetic neuropathy, spinal cord injury, bone cancer, opioid tolerance, or opioid-induced hyperalgesia. The potential targeting of CXCL12/CXCR4 axis as an effective and broad-spectrum pharmacological approach for chronic pain therapy was also discussed.published_or_final_versio