scispace - formally typeset
Search or ask a question

Showing papers by "University of Wollongong published in 2014"


Journal ArticleDOI
TL;DR: This review provides a summary of the recent occurrence of micropollutants in the aquatic environment including sewage, surface water, groundwater and drinking water.

2,933 citations


Journal ArticleDOI
21 Feb 2014-Science
TL;DR: In this article, high-strength polymer fibers used for fishing line and sewing thread can be easily transformed by twist insertion to provide fast, scalable, nonhysteretic, long-life tensile and torsional muscles.
Abstract: The high cost of powerful, large-stroke, high-stress artificial muscles has combined with performance limitations such as low cycle life, hysteresis, and low efficiency to restrict applications. We demonstrated that inexpensive high-strength polymer fibers used for fishing line and sewing thread can be easily transformed by twist insertion to provide fast, scalable, nonhysteretic, long-life tensile and torsional muscles. Extreme twisting produces coiled muscles that can contract by 49%, lift loads over 100 times heavier than can human muscle of the same length and weight, and generate 5.3 kilowatts of mechanical work per kilogram of muscle weight, similar to that produced by a jet engine. Woven textiles that change porosity in response to temperature and actuating window shutters that could help conserve energy were also demonstrated. Large-stroke tensile actuation was theoretically and experimentally shown to result from torsional actuation.

880 citations


Journal ArticleDOI
TL;DR: In this paper, a generalized and fundamental approach to molecular self-assembly synthesis of ultrathin 2D nanosheets of transition metal oxides by rationally employing lamellar reverse micelles is presented.
Abstract: Two-dimensional (2D) transition metal oxide systems present exotic electronic properties and high specific surface areas, and also demonstrate promising applications ranging from electronics to energy storage. Yet, in contrast to other types of nanostructures, the question as to whether we could assemble 2D nanomaterials with an atomic thickness from molecules in a general way, which may give them some interesting properties such as those of graphene, still remains unresolved. Herein, we report a generalized and fundamental approach to molecular self-assembly synthesis of ultrathin 2D nanosheets of transition metal oxides by rationally employing lamellar reverse micelles. It is worth emphasizing that the synthesized crystallized ultrathin transition metal oxide nanosheets possess confined thickness, high specific surface area and chemically reactive facets, so that they could have promising applications in nanostructured electronics, photonics, sensors, and energy conversion and storage devices.

715 citations


Journal ArticleDOI
06 Nov 2014-Nature
TL;DR: A more coordinated approach to risk management and land-use planning in these coupled systems is needed because fire will never operate as a natural ecosystem process, and the impact on society will continue to grow.
Abstract: The impacts of escalating wildfire in many regions - the lives and homes lost, the expense of suppression and the damage to ecosystem services - necessitate a more sustainable coexistence with wildfire. Climate change and continued development on fire-prone landscapes will only compound current problems. Emerging strategies for managing ecosystems and mitigating risks to human communities provide some hope, although greater recognition of their inherent variation and links is crucial. Without a more integrated framework, fire will never operate as a natural ecosystem process, and the impact on society will continue to grow. A more coordinated approach to risk management and land-use planning in these coupled systems is needed.

685 citations


Journal ArticleDOI
14 Jul 2014-ACS Nano
TL;DR: The first report on a SnS@graphene architecture for application as a sodium-ion battery anode, which is built from two-dimensional SnS and graphene nanosheets as complementary building blocks, finds the performance was found to be much better than those of most reported anode materials for Na-ion batteries.
Abstract: Structural phase transitions can be used to alter the properties of a material without adding any additional elements and are therefore of significant technological value. It was found that the hexagonal-SnS2 phase can be transformed into the orthorhombic-SnS phase after an annealing step in an argon atmosphere, and the thus transformed SnS shows enhanced sodium-ion storage performance over that of the SnS2, which is attributed to its structural advantages. Here, we provide the first report on a SnS@graphene architecture for application as a sodium-ion battery anode, which is built from two-dimensional SnS and graphene nanosheets as complementary building blocks. The as-prepared SnS@graphene hybrid nanostructured composite delivers an excellent specific capacity of 940 mAh g–1and impressive rate capability of 492 and 308 mAh g–1 after 250 cycles at the current densities of 810 and 7290 mA g–1, respectively. The performance was found to be much better than those of most reported anode materials for Na-ion ...

567 citations


Journal ArticleDOI
TL;DR: In this paper, a series of nitrogen-containing polymer and carbon spheres were obtained by the sol-gel method by one-pot hydrothermal synthesis in the presence of resorcinol/formaldehyde as carbon precursors and ethylenediamine (EDA) as both a base catalyst and nitrogen precursor, followed by carbonization in nitrogen and activation with CO2.
Abstract: A series of nitrogen-containing polymer and carbon spheres were obtained by the sol–gel method. In particular, the nitrogen-rich carbon spheres were prepared by one-pot hydrothermal synthesis in the presence of resorcinol/formaldehyde as carbon precursors and ethylenediamine (EDA) as both a base catalyst and nitrogen precursor, followed by carbonization in nitrogen and activation with CO2. The introduction of EDA to the sol–gel system resulted in structurally bonded nitrogen-containing carbon spheres. The nitrogen doping level and the particle size can be tuned by varying the EDA amount in the reaction mixture. The maximum nitrogen doping level of 7.2 wt % in carbon spheres could be achieved without sacrificing the spherical morphology. The diameter of these carbon spheres (CS) can be tuned in the rage of 50–1200 nm by varying the EDA amount. N2 adsorption analysis showed that the aforementioned activated carbon spheres exhibited high surface area reaching up to1224 m2/g. Ultra high CO2 adsorption capacit...

508 citations


Journal ArticleDOI
05 Dec 2014-Science
TL;DR: Results reveal that recruited neutrophils scan for activated platelets, and they suggest that the neutrophil’ bipolarity allows the integration of signals present at both the endothelium and the circulation before inflammation proceeds, which alleviated collateral inflammatory damage to tissues in several injury models in mice.
Abstract: Immune and inflammatory responses require leukocytes to migrate within and through the vasculature, a process that is facilitated by their capacity to switch to a polarized morphology with an asymmetric distribution of receptors. We report that neutrophil polarization within activated venules served to organize a protruding domain that engaged activated platelets present in the bloodstream. The selectin ligand PSGL-1 transduced signals emanating from these interactions, resulting in the redistribution of receptors that drive neutrophil migration. Consequently, neutrophils unable to polarize or to transduce signals through PSGL-1 displayed aberrant crawling, and blockade of this domain protected mice against thromboinflammatory injury. These results reveal that recruited neutrophils scan for activated platelets, and they suggest that the neutrophils' bipolarity allows the integration of signals present at both the endothelium and the circulation before inflammation proceeds.

506 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present a state-of-the-art review on the recent progress of magnetorheological elastomer technology, with special emphasis on the research and development of MR elastomers and their applications.
Abstract: During the last few decades, magnetorheological (MR) elastomers have attracted a significant amount of attention for their enormous potential in engineering applications. Because they are a solid counterpart to MR fluids, MR elastomers exhibit a unique field-dependent material property when exposed to a magnetic field, and they overcome major issues faced in magnetorheological fluids, e.g. the deposition of iron particles, sealing problems and environmental contamination. Such advantages offer great potential for designing intelligent devices to be used in various engineering fields, especially in fields that involve vibration reduction and isolation. This paper presents a state of the art review on the recent progress of MR elastomer technology, with special emphasis on the research and development of MR elastomer devices and their applications. To keep the integrity of the knowledge, this review includes a brief introduction of MR elastomer materials and follows with a discussion of critical issues involved in designing magnetorheological elastomer devices, i.e. operation modes, coil placements and principle fundamentals. A comprehensive review has been presented on the research and development of MR elastomer devices, including vibration absorbers, vibration isolators, base isolators, sensing devices, and so on. A summary of the research on the modeling mechanical behavior for both the material and the devices is presented. Finally, the challenges and the potential facing magnetorheological elastomer technology are discussed, and suggestions have been made based on the authors’ knowledge and experience.

498 citations


Journal ArticleDOI
TL;DR: In this article, high fluorescent cysteine-capped CdTe/CdS core-shell nanowires were successfully synthesized by reacting CdCl2 with NaHTe in aqueous solution under refluxing at 100°C for 140min.
Abstract: Highly fluorescent cysteine-capped CdTe/CdS core–shell nanowires were successfully synthesized by reacting CdCl2 with NaHTe in aqueous solution under refluxing at 100 °C for 140 min. On increasing the reaction time from 10 to 140 min, CdTe/CdS nanocrystals gradually grew into nanorods and eventually completely evolved into nanowires. The nanowires have amino and carboxyl functional groups on their surfaces and can be well dispersed in aqueous solution. The as-prepared CdTe/CdS nanowires show a fluorescence quantum yield (QY) of 7.25 % due to the unique nature of cysteine and the formation of a CdS shell on the surface of the CdTe core, they have a narrower diameter distribution (d = ~5 nm) and a length in the range of 175–275 nm, and their aspect ratio is between 1/35 and 1/55.

474 citations


Journal ArticleDOI
06 Feb 2014-Nature
TL;DR: The authors' analyses indicate that both graminoids and forbs would have featured in megafaunal diets, and question the predominance of a Late Quaternary graminoid-dominated Arctic mammoth steppe.
Abstract: Although it is generally agreed that the Arctic flora is among the youngest and least diverse on Earth, the processes that shaped it are poorly understood. Here we present 50 thousand years (kyr) of Arctic vegetation history, derived from the first large-scale ancient DNA metabarcoding study of circumpolar plant diversity. For this interval we also explore nematode diversity as a proxy for modelling vegetation cover and soil quality, and diets of herbivorous megafaunal mammals, many of which became extinct around 10 kyr bp (before present). For much of the period investigated, Arctic vegetation consisted of dry steppe-tundra dominated by forbs (non-graminoid herbaceous vascular plants). During the Last Glacial Maximum (25–15 kyr bp), diversity declined markedly, although forbs remained dominant. Much changed after 10 kyr bp, with the appearance of moist tundra dominated by woody plants and graminoids. Our analyses indicate that both graminoids and forbs would have featured in megafaunal diets. As such, our findings question the predominance of a Late Quaternary graminoid-dominated Arctic mammoth steppe.

460 citations


Journal ArticleDOI
TL;DR: There is now sufficient evidence that mangrove species have proliferated at or near their poleward limits on at least five continents over the past half century, at the expense of salt marsh, consistent with the poleward extension of temperature thresholds coincident with sea-level rise.
Abstract: Mangroves are species of halophytic intertidal trees and shrubs derived from tropical genera and are likely delimited in latitudinal range by varying sensitivity to cold. There is now sufficient evidence that mangrove species have proliferated at or near their poleward limits on at least five continents over the past half century, at the expense of salt marsh. Avicennia is the most cold-tolerant genus worldwide, and is the subject of most of the observed changes. Avicennia germinans has extended in range along the USA Atlantic coast and expanded into salt marsh as a consequence of lower frost frequency and intensity in the southern USA. The genus has also expanded into salt marsh at its southern limit in Peru, and on the Pacific coast of Mexico. Mangroves of several species have expanded in extent and replaced salt marsh where protected within mangrove reserves in Guangdong Province, China. In south-eastern Australia, the expansion of Avicennia marina into salt marshes is now well documented, and Rhizophora stylosa has extended its range southward, while showing strong population growth within estuaries along its southern limits in northern New South Wales. Avicennia marina has extended its range southwards in South Africa. The changes are consistent with the poleward extension of temperature thresholds coincident with sea-level rise, although the specific mechanism of range extension might be complicated by limitations on dispersal or other factors. The shift from salt marsh to mangrove dominance on subtropical and temperate shorelines has important implications for ecological structure, function, and global change adaptation.

Journal ArticleDOI
TL;DR: The gap in LE between Aboriginal people and the total Australian population appears to be unchanged since the early 1980s, and at the end of the first decade of the 21st century remains at least 11–12 years.
Abstract: Significant variation exists in published Aboriginal mortality and life expectancy (LE) estimates due to differing and evolving methodologies required to correct for inadequate recording of Aboriginality in death data, under-counting of Aboriginal people in population censuses, and unexplained growth in the Aboriginal population attributed to changes in the propensity of individuals to identify as Aboriginal at population censuses. The objective of this paper is to analyse variation in reported Australian Aboriginal mortality in terms of LE and infant mortality rates (IMR), compared with all Australians. Published data for Aboriginal LE and IMR were obtained and analysed for data quality and method of estimation. Trends in reported LE and IMR estimates were assessed and compared with those in the entire Australian population. LE estimates derived from different methodologies vary by as much as 7.2 years for the same comparison period. Indirect methods for estimating Aboriginal LE have produced LE estimates sensitive to small changes in underlying assumptions, some of which are subject to circular reasoning. Most indirect methods appear to under-estimate Aboriginal LE. Estimated LE gaps between Aboriginal people and the overall Australian population have varied between 11 and 20 years. Latest mortality estimates, based on linking census and death data, are likely to over-estimate Aboriginal LE. Temporal LE changes by each methodology indicate that Aboriginal LE has improved at rates similar to the Australian population overall. Consequently the gap in LE between Aboriginal people and the total Australian population appears to be unchanged since the early 1980s, and at the end of the first decade of the 21st century remains at least 11–12 years. In contrast, focussing on the 1990–2010 period Aboriginal IMR declined steeply over 2001–08, from more than 12 to around 8 deaths per 1,000 live births, the same level as Australia overall in 1993–95. The IMR gap between Aboriginal people and the total Australian population, while still unacceptable, has declined considerably, from over 8 before 2000 to around 4 per 1,000 live births by 2008. Regardless of estimation method used, mortality and LE gaps between Aboriginal and non-Aboriginal people are substantial, but remain difficult to estimate accurately.

Journal ArticleDOI
TL;DR: A facile ultrasonic approach with chemical activation using KOH to prepare activated GQDs or aGQDs enriched with both free and bound edges with superior luminescence holds potential for use in biomedical imaging and related optoelectronic applications.
Abstract: Graphene quantum dots (GQDs) with their edge-bound nanometer-size present distinctive properties owing to quantum confinement and edge effects. We report a facile ultrasonic approach with chemical activation using KOH to prepare activated GQDs or aGQDs enriched with both free and bound edges. Compared to GQDs, the aGQDs we synthesized had enhanced BET surface area by a factor of about six, the photoluminescence intensity by about four and half times and electro-capacitance by a factor of about two. Unlike their non-activated counterparts, the aGQDs having enhanced edge states emit enhanced intense blue luminescence and exhibit electrochemical double layer capacitance greater than that of graphene, activated or not. Apart from their use as part of electrodes in a supercapacitor, the superior luminescence of aGQDs holds potential for use in biomedical imaging and related optoelectronic applications.

Journal ArticleDOI
TL;DR: In this article, a symmetric supercapacitor based on Nanoporous Carbon (NPC) was designed by direct carbonization of Zn-based metal-organic frameworks (MOFs) without using an additional precursor.
Abstract: Nanoporous carbon (NPC) materials with high specific surface area have attracted considerable attention for electrochemical energy storage applications. In the present work, we have designed novel symmetric supercapacitors based on NPC by direct carbonization of Zn-based metal–organic frameworks (MOFs) without using an additional precursor. By controlling the reaction conditions in the present study, we synthesized NPC with two different particle sizes. The effects of particle size and mass loadings on supercapacitor performance have been carefully evaluated. Our NPC materials exhibit excellent electrochemical performance with a maximum specific capacitance of 251 F g−1 in 1 M H2SO4 electrolyte. The symmetric supercapacitor studies show that these efficient electrodes have good capacitance, high stability, and good rate capability.

Journal ArticleDOI
01 Mar 2014-Brain
TL;DR: Glucocerebrosidase deficits in sporadic Parkinson's disease are related to the abnormal accumulation of α-synuclein and are associated with substantial alterations in lysosomal chaperone-mediated autophagy pathways and lipid metabolism.
Abstract: Heterozygous mutations in GBA1, the gene encoding lysosomal glucocerebrosidase, are the most frequent known genetic risk factor for Parkinson’s disease. Reduced glucocerebrosidase and α-synuclein accumulation are directly related in cell models of Parkinson’s disease. We investigated relationships between Parkinson’s disease-specific glucocerebrosidase deficits, glucocerebrosidase-related pathways, and α-synuclein levels in brain tissue from subjects with sporadic Parkinson’s disease without GBA1 mutations. Brain regions with and without a Parkinson’s disease-related increase in α-synuclein levels were assessed in autopsy samples from subjects with sporadic Parkinson’s disease (n = 19) and age- and post-mortem delay-matched controls (n = 10). Levels of glucocerebrosidase, α-synuclein and related lysosomal and autophagic proteins were assessed by western blotting. Glucocerebrosidase enzyme activity was measured using a fluorimetric assay, and glucocerebrosidase and α-synuclein messenger RNA expression determined by quantitative polymerase chain reaction. Related sphingolipids were analysed by mass spectrometry. Multivariate statistical analyses were performed to identify differences between disease groups and regions, with non-parametric correlations used to identify relationships between variables. Glucocerebrosidase protein levels and enzyme activity were selectively reduced in the early stages of Parkinson’s disease in regions with increased α-synuclein levels although limited inclusion formation, whereas GBA1 messenger RNA expression was non-selectively reduced in Parkinson’s disease. The selective loss of lysosomal glucocerebrosidase was directly related to reduced lysosomal chaperone-mediated autophagy, increased α-synuclein and decreased ceramide. Glucocerebrosidase deficits in sporadic Parkinson’s disease are related to the abnormal accumulation of α-synuclein and are associated with substantial alterations in lysosomal chaperone-mediated autophagy pathways and lipid metabolism. Our data suggest that the early selective Parkinson’s disease changes are likely a result of the redistribution of cellular membrane proteins leading to a chronic reduction in lysosome function in brain regions vulnerable to Parkinson’s disease pathology.

Journal ArticleDOI
TL;DR: The authors make the case for a richer conception predicated on broader intellectual engagement and identify some preconditions for its practical fulfilment, and suggest that interdisciplinary dialogue should engender plural representations of Earth's present and future that are reflective of divergent human values and aspirations.
Abstract: Calls for more broad-based, integrated, useful knowledge now abound in the world of global environmental change science. They evidence many scientists' desire to help humanity confront the momentous biophysical implications of its own actions. But they also reveal a limited conception of social science and virtually ignore the humanities. They thereby endorse a stunted conception of 'human dimensions' at a time when the challenges posed by global environmental change are increasing in magnitude, scale and scope. Here, we make the case for a richer conception predicated on broader intellectual engagement and identify some preconditions for its practical fulfilment. Interdisciplinary dialogue, we suggest, should engender plural representations of Earth's present and future that are reflective of divergent human values and aspirations. In turn, this might insure publics and decision-makers against overly narrow conceptions of what is possible and desirable as they consider the profound questions raised by global environmental change.

Journal ArticleDOI
09 Oct 2014-Nature
TL;DR: It can now be demonstrated that humans were producing rock art by ∼40 kyr ago at opposite ends of the Pleistocene Eurasian world.
Abstract: Cave art from the island of Sulawesi in Indonesia, consisting of human hand stencils and animal paintings, is at least 40,000 years old, raising the question of why rock art traditions appeared at more or less the same time at opposite ends of the Late Pleistocene human world. New dating results challenge the traditional view that western Europe was the centre of a crucial stage in the evolution of modern human intelligence and culture — based largely on the emergence of figurative or representational art in cave paintings and sculptures around 40,000 years ago. Dating data from a series of hand stencils and paintings of wild animals from caves in the Maros karst in Sulawesi, Indonesia, suggest that figurative art appeared at more or less the same time at opposite ends of the Late Pleistocene world. Or was cave painting practised by the first Homo sapiens to leave Africa tens of thousands of years earlier? Archaeologists have long been puzzled by the appearance in Europe ∼40–35 thousand years (kyr) ago of a rich corpus of sophisticated artworks, including parietal art (that is, paintings, drawings and engravings on immobile rock surfaces)1,2 and portable art (for example, carved figurines)3,4, and the absence or scarcity of equivalent, well-dated evidence elsewhere, especially along early human migration routes in South Asia and the Far East, including Wallacea and Australia5,6,7,8, where modern humans (Homo sapiens) were established by 50 kyr ago9,10. Here, using uranium-series dating of coralloid speleothems directly associated with 12 human hand stencils and two figurative animal depictions from seven cave sites in the Maros karsts of Sulawesi, we show that rock art traditions on this Indonesian island are at least compatible in age with the oldest European art11. The earliest dated image from Maros, with a minimum age of 39.9 kyr, is now the oldest known hand stencil in the world. In addition, a painting of a babirusa (‘pig-deer’) made at least 35.4 kyr ago is among the earliest dated figurative depictions worldwide, if not the earliest one. Among the implications, it can now be demonstrated that humans were producing rock art by ∼40 kyr ago at opposite ends of the Pleistocene Eurasian world.

Journal ArticleDOI
TL;DR: In this paper, the authors present an update of the "key points" from the Antarctic Climate Change and the Environment (ACCE) report that was published by the Scientific Committee on Antarctic Research (SCAR) in 2009.
Abstract: We present an update of the ‘key points’ from the Antarctic Climate Change and the Environment (ACCE) report that was published by the Scientific Committee on Antarctic Research (SCAR) in 2009. We summarise subsequent advances in knowledge concerning how the climates of the Antarctic and Southern Ocean have changed in the past, how they might change in the future, and examine the associated impacts on the marine and terrestrial biota. We also incorporate relevant material presented by SCAR to the Antarctic Treaty Consultative Meetings, and make use of emerging results that will form part of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report

Journal ArticleDOI
TL;DR: The roles of organisational decision-making processes, including resource allocation processes and resource orchestration processes, need to be better understood in order to understand how organisations can create value from the use of business analytics.
Abstract: Much attention is currently being paid in both the academic and practitioner literatures to the value that organisations could create through the use of big data and business analytics (Gillon et a...

Journal ArticleDOI
TL;DR: In this article, the authors investigated whether a psychometric instrument can differentiate intrinsic, extraneous, and germane cognitive load, and found that a slightly modified version of the aforementioned psychometric device could help researchers to differentiate intrinsic and extraneous cognitive load.

Journal ArticleDOI
TL;DR: In this article, Brodie, Cowling, and Nissen's notion of categories of participation to generate 11 different ways that cooperating teachers participate in teacher education: Providers of Feedback, Gatekeepers of the Profession, Modelers of Practice, Supporters of Reflection, Gleaners of Knowledge, Purveyors of Context, Conveners of Relation, Agents of Socialization, Advocates of the Practical, Abiders of Change, and Teachers of Children.
Abstract: Student teachers consider cooperating teachers to be one of the most important contributors to their teacher preparation program. Therefore, the ways in which cooperating teachers participate in teacher education are significant. This review seeks to move conceptions of that participation beyond commonly held beliefs to empirically supported claims. The analysis draws on Brodie, Cowling, and Nissen’s notion of categories of participation to generate 11 different ways that cooperating teachers participate in teacher education: as Providers of Feedback, Gatekeepers of the Profession, Modelers of Practice, Supporters of Reflection, Gleaners of Knowledge, Purveyors of Context, Conveners of Relation, Agents of Socialization, Advocates of the Practical, Abiders of Change, and Teachers of Children. When set against Gaventa’s typology of participation, the resultant grid highlights the importance of negotiated or invited spaces for cooperating teacher participation and provides a new way of thinking about, planni...

Journal ArticleDOI
TL;DR: Research on containership routing and scheduling lags behind practice, especially in the face of the fast growth of the container shipping industry and the advancement of operations research and computer technology, so this paper is to stimulate more practically relevant research in this emerging area.
Abstract: This paper reviews studies from the past 30 years that use operations research methods to tackle containership routing and scheduling problems at the strategic, tactical, and operational planning levels. These problems are first classified and summarized, with a focus on model formulations, assumptions, and algorithm design. The paper then gives an overview of studies on containership fleet size and mix, alliance strategy, and network design at the strategic level; frequency determination, fleet deployment, speed optimization, and schedule design at the tactical level; and container booking and routing and ship rescheduling at the operational level. The paper further elaborates on the needs of the liner container shipping industry and notes the gap between existing academic studies and industrial practices. Research on containership routing and scheduling lags behind practice, especially in the face of the fast growth of the container shipping industry and the advancement of operations research and computer technology. The purpose of this paper is to stimulate more practically relevant research in this emerging area.

Journal ArticleDOI
TL;DR: In this paper, an overview of the range of available terahertz sources, emphasizing recent developments, is given, and the focus then narrows to the sources that rely on surface phenomena.
Abstract: Bibliometric data set the scene by illustrating the growth of terahertz work and the present interest in terahertz science and technology. After locating terahertz sources within the broader context of terahertz systems, an overview is given of the range of available sources, emphasizing recent developments. The focus then narrows to terahertz sources that rely on surface phenomena. Three are highlighted. Optical rectification, usually thought of as a bulk process, may in addition exhibit a surface contribution, which, in some cases, predominates. Transient surface currents, for convenience often separated into drift and diffusion currents, are well understood according to Monte Carlo modelling. Finally, terahertz surface emission by mechanical means—in the absence of photoexcitation—is described.

Journal ArticleDOI
TL;DR: HuWtSOD1 can traverse between cells via two nonexclusive mechanisms: protein aggregates released from dying cells and taken up by macropinocytosis, and exosomes secreted from living cells as mentioned in this paper.
Abstract: Amyotrophic lateral sclerosis (ALS) is predominantly sporadic, but associated with heritable genetic mutations in 5-10% of cases, including those in Cu/Zn superoxide dismutase (SOD1) We previously showed that misfolding of SOD1 can be transmitted to endogenous human wild-type SOD1 (HuWtSOD1) in an intracellular compartment Using NSC-34 motor neuron-like cells, we now demonstrate that misfolded mutant and HuWtSOD1 can traverse between cells via two nonexclusive mechanisms: protein aggregates released from dying cells and taken up by macropinocytosis, and exosomes secreted from living cells Furthermore, once HuWtSOD1 propagation has been established, misfolding of HuWtSOD1 can be efficiently and repeatedly propagated between HEK293 cell cultures via conditioned media over multiple passages, and to cultured mouse primary spinal cord cells transgenically expressing HuWtSOD1, but not to cells derived from nontransgenic littermates Conditioned media transmission of HuWtSOD1 misfolding in HEK293 cells is blocked by HuWtSOD1 siRNA knockdown, consistent with human SOD1 being a substrate for conversion, and attenuated by ultracentrifugation or incubation with SOD1 misfolding-specific antibodies, indicating a relatively massive transmission particle which possesses antibody-accessible SOD1 Finally, misfolded and protease-sensitive HuWtSOD1 comprises up to 4% of total SOD1 in spinal cords of patients with sporadic ALS (SALS) Propagation of HuWtSOD1 misfolding, and its subsequent cell-to-cell transmission, is thus a candidate process for the molecular pathogenesis of SALS, which may provide novel treatment and biomarker targets for this devastating disease

Journal ArticleDOI
TL;DR: Results from UV-vis absorption study, Electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopic suggest that the improved photoactivity is due to a decrease in band gap energy, an increased light absorption in visible light region and possibly an enhanced electron-hole separation efficiency as a result of effective interfacial electron transfer between TiO2 and g-C3N4 of the g-N4/TiO2 composite film.

Journal ArticleDOI
Shulei Chou1, Yuede Pan1, Jiazhao Wang1, Hua-Kun Liu1, Shi Xue Dou1 
TL;DR: This review focuses on several kinds of promising electrode materials, to show how their battery performance can be affected significantly by binder materials: anode materials such as Si, Sn and transitional metal oxides; cathodematerials such as LiFePO4, LiNi1/3Co 1/3Mn1/ 3O2, LiCoO2 and sulphur.
Abstract: Li and Na batteries are very important as energy storage devices for electric vehicles and smart grids It is well known that, when an electrode is analysed in detail, each of the components (the active material, the conductive carbon, the current collector and the binder) makes a portion of contribution to the battery performance in terms of specific capacity, rate capability, cycle life, etc However, there has not yet been a review on the binder, though there are already many review papers on the active materials Binders make up only a small part of the electrode composition, but in some cases, they play an important role in affecting the cycling stability and rate capability for Li-ion and Na-ion batteries Poly(vinylidene difluoride) (PVDF) has been the mainstream binder, but there have been discoveries that aqueous binders can sometimes make a battery perform better, not to mention they are cheaper, greener, and easier to use for electrode fabrication In this review, we focus on several kinds of promising electrode materials, to show how their battery performance can be affected significantly by binder materials: anode materials such as Si, Sn and transitional metal oxides; cathode materials such as LiFePO4, LiNi1/3Co1/3Mn1/3O2, LiCoO2 and sulphur

Journal ArticleDOI
17 Feb 2014-ACS Nano
TL;DR: A large-scale flexible fabrication of highly porous high-performance multifunctional graphene oxide (GO) and rGO fibers and yarns by taking advantage of the intrinsic soft self-assembly behavior of ultralarge graphene oxide liquid crystalline dispersions is demonstrated.
Abstract: The successful commercialization of smart wearable garments is hindered by the lack of fully integrated carbon-based energy storage devices into smart wearables. Since electrodes are the active components that determine the performance of energy storage systems, it is important to rationally design and engineer hierarchical architectures atboth the nano- and macroscale that can enjoy all of the necessary requirements for a perfect electrode. Here we demonstrate a large-scale flexible fabrication of highly porous high-performance multifunctional graphene oxide (GO) and rGO fibers and yarns by taking advantage of the intrinsic soft self-assembly behavior of ultralarge graphene oxide liquid crystalline dispersions. The produced yarns, which are the only practical form of these architectures for real-life device applications, were found to be mechanically robust (Young’s modulus in excess of 29 GPa) and exhibited high native electrical conductivity (2508 ± 632 S m–1) and exceptionally high specific surface ar...

Journal ArticleDOI
TL;DR: In this article, a bismuth-based photocatalyst, Bi24O31Br10, with reasonable reduction activity was reported, which showed that the bottom of the conduction band fits the electric potential requirements for splitting water to H-2.
Abstract: The original bismuth-based oxyhalide, known as the Sillen family, is an important photocatalyst due to its high photocatalytic oxidation activity. Here, we report a bismuth-based photocatalyst, Bi24O31Br10, with reasonable reduction activity. The photoreduction capability of Bi24O31Br10 in H-2 evolution from water reduction is 133.9 mu mol after 40 h under visible light irradiation. Bi24O31Br10 presents the highest activity among Bi2O3, BiOBr, and Bi24O31Br10 in photocatalytic reduction of the Cr (VI) test, and Cr (VI) ions are totally removed in 40 mm. The Mott-Schottky test shows the bottom of the conduction band fits the electric potential requirements for splitting water to H-2. First-principles calculations indicate the conduction band of Bi24O31Br10 mainly consists of hybridized Bi 6p and Br 4s orbitals, which may contribute to the uplifting of the conduction band.

Journal ArticleDOI
TL;DR: Sn4+x P3 @ amorphous Sn-P composites are a promising cheap anode material for sodium-ion batteries with high capacity, long cycling stability, and high rate capability.
Abstract: Sn4+x P3 @ amorphous Sn-P composites are a promising cheap anode material for sodium-ion batteries with high capacity (502 mA h g(-1) at a current density of 100 mA g(-1)), long cycling stability (92.6% capacity retention up to 100 cycles), and high rate capability (165 mA h g(-1) at the 10C rate).

Journal ArticleDOI
TL;DR: It is proposed that a gold standard deep-body temperature does not exist and the validity of each measurement must be evaluated relative to one's research objectives, whilst satisfying equilibration and positioning requirements.