scispace - formally typeset
Search or ask a question

Showing papers by "Hong Kong University of Science and Technology published in 2012"


Journal ArticleDOI
TL;DR: In this paper, the authors extended the unified theory of acceptance and use of technology (UTAUT) to study acceptance of technology in a consumer context and proposed UTAUT2 incorporating three constructs into UTAAUT: hedonic motivation, price value, and habit.
Abstract: This paper extends the unified theory of acceptance and use of technology (UTAUT) to study acceptance and use of technology in a consumer context. Our proposed UTAUT2 incorporates three constructs into UTAUT: hedonic motivation, price value, and habit. Individual differences--namely, age, gender, and experience--are hypothesized to moderate the effects of these constructs on behavioral intention and technology use. Results from a two-stage online survey, with technology use data collected four months after the first survey, of 1,512 mobile Internet consumers supported our model. Compared to UTAUT, the extensions proposed in UTAUT2 produced a substantial improvement in the variance explained in behavioral intention (56 percent to 74 percent) and technology use (40 percent to 52 percent). The theoretical and managerial implications of these results are discussed.

6,744 citations


Posted Content
TL;DR: In this paper, the authors extended the unified theory of acceptance and use of technology (UTAUT) to study acceptance of technology in a consumer context and proposed UTAUT2 incorporating three constructs into UTAAUT: hedonic motivation, price value, and habit.
Abstract: This paper extends the unified theory of acceptance and use of technology (UTAUT) to study acceptance and use of technology in a consumer context. Our proposed UTAUT2 incorporates three constructs into UTAUT: hedonic motivation, price value, and habit. Individual differences — namely, age, gender, and experience — are hypothesized to moderate the effects of these constructs on behavioral intention and technology use. Results from a two-stage online survey, with technology use data collected four months after the first survey, of 1,512 mobile Internet consumers supported our model. Compared to UTAUT, the extensions proposed in UTAUT2 produced a substantial improvement in the variance explained in behavioral intention (56 percent to 74 percent) and technology use (40 percent to 52 percent). The theoretical and managerial implications of these results are discussed.

4,986 citations


Journal ArticleDOI
TL;DR: These guidelines are presented for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes.
Abstract: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

4,316 citations


Journal ArticleDOI
08 Nov 2012-Nature
TL;DR: It is proposed that barrier deterioration induced by colorectal-cancer-initiating genetic lesions results in adenoma invasion by microbial products that trigger tumour-elicited inflammation, which in turn drives tumour growth.
Abstract: Approximately 2% of colorectal cancer is linked to pre-existing inflammation known as colitis-associated cancer, but most develops in patients without underlying inflammatory bowel disease. Colorectal cancer often follows a genetic pathway whereby loss of the adenomatous polyposis coli (APC) tumour suppressor and activation of β-catenin are followed by mutations in K-Ras, PIK3CA and TP53, as the tumour emerges and progresses. Curiously, however, 'inflammatory signature' genes characteristic of colitis-associated cancer are also upregulated in colorectal cancer. Further, like most solid tumours, colorectal cancer exhibits immune/inflammatory infiltrates, referred to as 'tumour-elicited inflammation'. Although infiltrating CD4(+) T(H)1 cells and CD8(+) cytotoxic T cells constitute a positive prognostic sign in colorectal cancer, myeloid cells and T-helper interleukin (IL)-17-producing (T(H)17) cells promote tumorigenesis, and a 'T(H)17 expression signature' in stage I/II colorectal cancer is associated with a drastic decrease in disease-free survival. Despite its pathogenic importance, the mechanisms responsible for the appearance of tumour-elicited inflammation are poorly understood. Many epithelial cancers develop proximally to microbial communities, which are physically separated from immune cells by an epithelial barrier. We investigated mechanisms responsible for tumour-elicited inflammation in a mouse model of colorectal tumorigenesis, which, like human colorectal cancer, exhibits upregulation of IL-23 and IL-17. Here we show that IL-23 signalling promotes tumour growth and progression, and development of a tumoural IL-17 response. IL-23 is mainly produced by tumour-associated myeloid cells that are likely to be activated by microbial products, which penetrate the tumours but not adjacent tissue. Both early and late colorectal neoplasms exhibit defective expression of several barrier proteins. We propose that barrier deterioration induced by colorectal-cancer-initiating genetic lesions results in adenoma invasion by microbial products that trigger tumour-elicited inflammation, which in turn drives tumour growth.

1,069 citations


Journal ArticleDOI
TL;DR: The authors study whether managers use real activities manipulation and accrual-based earnings management as substitutes in managing earnings and find that managers trade off the two earnings manage managers, and they conclude that managers do not.
Abstract: I study whether managers use real activities manipulation and accrual-based earnings management as substitutes in managing earnings. I find that managers trade off the two earnings manage...

945 citations


Journal ArticleDOI
TL;DR: In this paper, three psychological antecedents (psychological safety, felt obligation for constructive change, and organization-based self-esteem) uniquely, differentially, and interactively predict supervisory reports of promotive and prohibitive "voice" behavior.
Abstract: The present study demonstrates how three psychological antecedents (psychological safety, felt obligation for constructive change, and organization-based self-esteem) uniquely, differentially, and interactively predict supervisory reports of promotive and prohibitive “voice” behavior. Using a two-wave panel design, we collected data from a sample of 239 employees to examine the hypothesized relationships. Our results showed that felt obligation was most strongly related to subsequent promotive voice; psychological safety was most strongly related to subsequent prohibitive voice; and organization-based self-esteem was reciprocally related to promotive voice. Further, although felt obligation strengthened the positive effect of psychological safety on both forms of voice, organization-based self-esteem weakened this effect for promotive voice. Theoretical and practical implications are discussed.

944 citations


Journal ArticleDOI
TL;DR: A thin-film acoustic metamaterial, comprising an elastic membrane decorated with asymmetric rigid platelets that aims to totally absorb low-frequency airborne sound at selective resonance frequencies ranging from 100-1,000 Hz, can reach almost unity absorption at frequencies where the relevant sound wavelength in air is three orders of magnitude larger than the membrane thickness.
Abstract: The attenuation of low-frequency sound has been a challenging task because the intrinsic dissipation of materials is inherently weak in this regime. Here we present a thin-film acoustic metamaterial, comprising an elastic membrane decorated with asymmetric rigid platelets that aims to totally absorb low-frequency airborne sound at selective resonance frequencies ranging from 100-1,000 Hz. Our samples can reach almost unity absorption at frequencies where the relevant sound wavelength in air is three orders of magnitude larger than the membrane thickness. At resonances, the flapping motion of the rigid platelets leads naturally to large elastic curvature energy density at their perimeter regions. As the flapping motions couple only minimally to the radiation modes, the overall energy density in the membrane can be two-to-three orders of magnitude larger than the incident wave energy density at low frequencies, forming in essence an open cavity.

798 citations


Journal ArticleDOI
TL;DR: In this article, a new class of propeller-like luminogenic molecules with aggregation-induced emission (AIE) characteristics has drawn increasing research interest, and tetraphenylethene (TPE) is an archetypal luminogen with a simple molecule structure.
Abstract: Luminescent materials with efficient solid-state emissions are important for the advancement of optoelectronics. Recently, a new class of propeller-like luminogenic molecules with aggregation-induced emission (AIE) characteristics has drawn increasing research interest. Among them, tetraphenylethene (TPE) is an archetypal luminogen with a simple molecule structure but shows a splendid AIE effect. Utilizing TPE as a building block, an effective strategy to create efficient solid-state emitters is developed. In this feature article, we review mainly our recent work on the construction of luminogenic materials from TPE and present their applications in organic light-emitting diodes. The applicability of the synthetic strategy and the utility of the resulting materials are demonstrated.

707 citations


Journal ArticleDOI
TL;DR: Elevated levels of metal contamination along China's coastal environment can increase the risk of metal exposure to humans by seafood consumption, raising the alarm for more stringent control of discharge of metals into environment.

652 citations


Journal ArticleDOI
TL;DR: In this paper, a facile electrochemical method for synthesizing uniform sized graphene quantum dots (GQDs) with a strong yellow emission at 14% quantum yield was presented, which enabled a large-scale production of aqueous GQD solution without the need for polymeric or surfactant stabilizers.
Abstract: We present a facile electrochemical method for synthesizing uniform sized graphene quantum dots (GQDs) with a strong yellow emission at 14% quantum yield. This approach has enabled a large-scale production of aqueous GQD solution without the need for polymeric or surfactant stabilizers. The structure and emission mechanism of the GQDs have been studied by combining extensive characterization techniques, rigorous control experiments and theoretical calculations. We further demonstrate the distinctive advantages of such GQDs for direct and efficient stem cell labeling, opening up great opportunities for their bio-medical applications.

647 citations


Journal ArticleDOI
TL;DR: The AIE‐active fluorogen‐loaded BSA NPs show an excellent cancer cell uptake and a prominent tumor‐targeting ability in vivo due to the enhanced permeability and retention effect.
Abstract: Light emission of 2-(2,6-bis((E)-4-(diphenylamino)styryl)-4H-pyran-4-ylidene)malononitrile (TPA-DCM) is weakened by aggregate formation. Attaching tetraphenylethene (TPE) units as terminals to TPA-DCM dramatically changes its emission behavior: the resulting fluorogen, 2-(2,6-bis((E)-4-(phenyl(4′-(1,2,2-triphenylvinyl)-[1,1′-biphenyl]-4-yl)amino)styryl)-4H-pyran-4-ylidene)malononitrile (TPE-TPA-DCM), is more emissive in the aggregate state, showing the novel phenomenon of aggregation-induced emission (AIE). Formulation of TPE-TPA-DCM using bovine serum albumin (BSA) as the polymer matrix yields uniformly sized protein nanoparticles (NPs) with high brightness and low cytotoxicity. Applications of the fluorogen-loaded BSA NPs for in vitro and in vivo far-red/near-infrared (FR/NIR) bioimaging are successfully demonstrated using MCF-7 breast-cancer cells and a murine hepatoma-22 (H22)-tumor-bearing mouse model, respectively. The AIE-active fluorogen-loaded BSA NPs show an excellent cancer cell uptake and a prominent tumor-targeting ability in vivo due to the enhanced permeability and retention effect.

Posted Content
TL;DR: A new network architecture that overlays an uplink cellular network with randomly deployed PBs for powering mobiles, called a hybrid network, is proposed and it is proved that the outage constraint is satisfied so long as the product pλbα/2 is above a given threshold where α is the path-loss exponent.
Abstract: Microwave power transfer (MPT) delivers energy wirelessly from stations called power beacons (PBs) to mobile devices by microwave radiation. This provides mobiles practically infinite battery lives and eliminates the need of power cords and chargers. To enable MPT for mobile charging, this paper proposes a new network architecture that overlays an uplink cellular network with randomly deployed PBs for powering mobiles, called a hybrid network. The deployment of the hybrid network under an outage constraint on data links is investigated based on a stochastic-geometry model where single-antenna base stations (BSs) and PBs form independent homogeneous Poisson point processes (PPPs) and single-antenna mobiles are uniformly distributed in Voronoi cells generated by BSs. In this model, mobiles and PBs fix their transmission power at p and q, respectively; a PB either radiates isotropically, called isotropic MPT, or directs energy towards target mobiles by beamforming, called directed MPT. The model is applied to derive the tradeoffs between the network parameters including p, q, and the BS/PB densities under the outage constraint. First, consider the deployment of the cellular network. It is proved that the outage constraint is satisfied so long as the product the BS density decreases with increasing p following a power law where the exponent is proportional to the path-loss exponent. Next, consider the deployment of the hybrid network assuming infinite energy storage at mobiles. It is shown that for isotropic MPT, the product between q, the PB density, and the BS density raised to a power proportional to the path-loss exponent has to be above a given threshold so that PBs are sufficiently dense; for directed MPT, a similar result is obtained with the aforementioned product increased by the array gain. Last, similar results are derived for the case of mobiles having small energy storage.

Journal ArticleDOI
TL;DR: In this work, pure stereoisomers of a TPE derivative named 1,2-bis{4-[1-(6-phenoxyhexyl)-4-(1,2,3-triazol)yl]phenyl}-1, 2-diphenylethene (BPHTATPE) are successfully synthesized and both isomers show remarkable AIE effect and high fluorescence quantum yield in the solid state.
Abstract: It has been difficult to decipher the mechanistic issue whether E/Z isomerization is involved in the aggregation-induced emission (AIE) process of a tetraphenylethene (TPE) derivative, due to the difficulty in the synthesis of its pure E and Z conformers. In this work, pure stereoisomers of a TPE derivative named 1,2-bis{4-[1-(6-phenoxyhexyl)-4-(1,2,3-triazol)yl]phenyl}-1,2-diphenylethene (BPHTATPE) are successfully synthesized. Both isomers show remarkable AIE effect (αAIE ≥ 322) and high fluorescence quantum yield in the solid state (ΦF 100%). The conformers readily undergo E/Z isomerization upon exposure to a powerful UV light and treatment at a high temperature (>200 °C). Such conformational change, however, is not observed under normal fluorescence spectrum measurement conditions, excluding the involvement of the E/Z isomerization in the AIE process of the TPE-based luminogen. The molecules of (E)-BPHTATPE self-organize into ordered one-dimensional nanostructures such as microfibers and nanorods that...

Journal ArticleDOI
TL;DR: A new live-cell-permeable, fluorescent light-up probe is designed and synthesized for real-time cell apoptosis imaging that provides a new opportunity to screen enzyme inhibitors and evaluate the apoptosis-associated drug efficacy.
Abstract: Real-time monitoring of cell apoptosis could provide valuable insights into early detection of therapy efficiency and evaluation of disease progression. In this work, we designed and synthesized a new live-cell-permeable, fluorescent light-up probe for real-time cell apoptosis imaging. The probe is comprised of a hydrophilic caspase-specific Asp-Glu-Val-Asp (DEVD) peptide and a hydrophobic tetraphenylethene (TPE) unit, a typical fluorogen with aggregation-induced emission characteristics. In aqueous solution, the probe is almost nonfluorescent but displays significant fluorescence enhancement in response to caspase-3/-7, which are activated in the apoptotic process and able to cleave the DEVD moieties. This fluorescence “turn-on” response is ascribed to aggregation of cleaved hydrophobic TPE residues, which restricts the intramolecular rotations of TPE phenyl rings and populates the radiative decay channels. The light-up nature of the probe allows real-time monitoring of caspase-3/-7 activities both in so...

PatentDOI
TL;DR: A method for detecting pH in a sample solution with a certain pH value comprising contacting the sample solution using a water-soluble tetraphenylethene-cored probe having multiple functionalities of boronic acid and aggregation induced emission (AIE) characteristics, and detecting fluorescence as discussed by the authors.
Abstract: A method of detecting the presence or absence of saccharide or saccharide level in a biological or artificial sample comprising contacting the sample with a water-soluble tetraphenylethene-cored probe having multiple functionalities of boronic acid and aggregation induced emission (AIE) characteristics, and detecting fluorescence. A method for detecting pH in a sample solution with a certain pH value comprising contacting the sample solution with a water-soluble tetraphenylethene-cored probe having multiple functionalities of boronic acid and aggregation induced emission (AIE) characteristics, and detecting fluorescence.

Journal ArticleDOI
TL;DR: In this article, different manufacturing processes and their suitability for natural fibre composites, based on the materials, mechanical and thermal properties of the fibres and matrices are discussed in detail.
Abstract: Elevated environmental awareness of the general public in reducing carbon footprints and the use nonnaturally decomposed solid wastes has resulted in an increasing use of natural materials, biodegradable and recyclable polymers and their composites for a wide range of engineering applications. The properties of natural fibre reinforced polymer composites are generally governed by the pre-treated process of fibre and the manufacturing process of the composites. These properties can be tailored for various types of applications by properly selecting suitable fibres, matrices, additives and production methods. Besides, due to the complexity of fibre structures, different mechanical performances of the composites are obtained even with the use of the same fibre types with different matrices. Some critical issues like poor wettability, poor bonding and degradation at the fibre/matrix interface (a hydrophilic and hydrophobic effect) and damage of the fibre during the manufacturing process are the main causes of the reduction of the composites’ strength. In this paper, different manufacturing processes and their suitability for natural fibre composites, based on the materials, mechanical and thermal properties of the fibres and matrices are discussed in detail.

Journal ArticleDOI
TL;DR: In this paper, a carbon-supported Co3O4 electrocatalyst with nano-rods and spherical structures is reported for the oxygen reduction reaction (ORR) in alkaline media.
Abstract: We report preparation of carbon-supported Co3O4 electrocatalysts with nano-rods and spherical structures by the solvent-mediated morphological control method. The catalytic properties of the prepared catalysts for the oxygen reduction reaction (ORR) in alkaline media are investigated. We show that the ORR catalytic activity of the prepared catalysts is sensitive to the number and activity of surface-exposed Co3+ ions that can be tailored by the morphology of cobalt oxides. In particular, we demonstrate that the non-precious Co3O4 electrocatalyst with the nano-rod structure (∼12 nm in length and ∼5.1 nm in diameter) prepared in the mixed solvent of water to dimethylformamide ratio of 1 : 1 exhibits a higher current density than a much more expensive palladium-based catalyst does at the low potential region.

Journal ArticleDOI
18 Jan 2012-ACS Nano
TL;DR: A tentative hypothesis stressing the competition between the conductivity increase and the amorphorization of the composite electrodes during cycling in determining the trends of the capacity is proposed in the hope of gaining a fuller understanding of the inner working of the novel nanostructured electrode-based lithium-ion batteries.
Abstract: In this paper, we report a facile ultrasonic method to synthesize well-dispersed CoO quantum dots (3-8 nm) on graphene nanosheets at room temperature by employing Co(4)(CO)(12) as cobalt precursor. The prepared CoO/graphene composites displayed high performance as an anode material for lithium-ion battery, such as high reversible lithium storage capacity (1592 mAh g(-1) after 50 cycles), high Coulombic efficiency (over 95%), excellent cycling stability, and high rate capability (1008 mAh g(-1) with a total retention of 77.6% after 50 cycles at a current density of 1000 mA g(-1), dramatically increased from the initial 50 mA g(-1)). The extraordinary performance arises from the structure advantages of the composites: the nanosized CoO quantum dots with high dispersity on conductive graphene substrates supply not only large quantity of accessible active sites for lithium-ion insertion but also good conductivity and short diffusion length for lithium ions, which are beneficial for high capacity and rate capability. Meanwhile, the isolated CoO quantum dots anchored tightly on the graphene nanosheets can effectively circumvent the volume expansion/contraction associated with lithium insertion/extraction during discharge/charge processes, which is good for high capacity as well as cycling stability. Moreover, regarding the anomalous behavior of capacity increase with cycles (activation effect) observed, we proposed a tentative hypothesis stressing the competition between the conductivity increase and the amorphorization of the composite electrodes during cycling in determining the trends of the capacity, in the hope to gain a fuller understanding of the inner working of the novel nanostructured electrode-based lithium-ion batteries.

Journal ArticleDOI
TL;DR: Using in vivo time-lapse imaging of both microglial morphology and neuronal activity in the optic tectum of larval zebrafish, it is found that neuronal activity steers resting microglia processes and facilitates their contact with highly active neurons.

Journal ArticleDOI
TL;DR: In this paper, the authors report the triphenylamine (TPA) and 2,3,3-triphenylacrylonitrile (TPAN) based EEM architectures, namely, TPA3TPAN and DTPA4TPAN.
Abstract: Emissive electron donor–acceptor (D–A) conjugates have a wide variety of applications in biophotonics, two-photon absorption materials, organic lasers, long wavelength emitters, and so forth. However, it is still a challenge to synthesize high solid-state efficiency D–A structured emitters due to the notorious aggregation-caused quenching (ACQ) effect. Though some D–A systems are reported to show aggregation-induced emission (AIE) behaviors, most are only selectively AIE-active in highly polar solvents, showing decreased solid-sate emission efficiencies compared to those in nonpolar solvents. Here we report the triphenylamine (TPA) and 2,3,3-triphenylacrylonitrile (TPAN) based D–A architectures, namely, TPA3TPAN and DTPA4TPAN. Decoration of arylamines with TPAN changes their emission behaviors from ACQ to AIE, making resulting TPA3TPAN and DTPA4TPAN nonluminescent in common solvents but highly emissive when aggregated as nanoparticles, solid powders, and thin films owing to their highly twisted configurat...

Journal ArticleDOI
TL;DR: In this paper, the authors theoretically identify three dimensions of expatriate competenciesability, motivation, and opportunity seeking for knowledge transfer: ability-motivation-opportunity framework and the absorptive capacity perspective.
Abstract: In this study, we theoretically identify three dimensions of expatriate competenciesability, motivation, and opportunity seeking—for knowledge transfer. Integrating the ability-motivation-opportunity framework and the absorptive capacity perspective, we propose that expatriate competencies in knowledge transfer influence a subsidiary's performance through the knowledge received by the subsidiary, but tbat this indirect enect is stronger when subsidiary absorptive capacity is greater. We collected multisource, time-lagged data from 162 British subsidiaries of Taiwanese multinational nrms. The results support our hypotheses. Overall, we contribute to expatriation theory and research by revealing specinc expatriate competencies as well as identifying boundary conditions for successful expatriate knowledge transfer.

Journal ArticleDOI
TL;DR: In this paper, the authors focus on manufacturing firms' innovative performance, measured by patent-based metrics, and employ exogenous variations in banking development arising from the staggered deregulation of banking activities across US states during the 1980s and 1990s.
Abstract: We present evidence that banking development plays a key role in technological progress. We focus on manufacturing firms’ innovative performance, measured by patent-based metrics, and employ exogenous variations in banking development arising from the staggered deregulation of banking activities across US states during the 1980s and 1990s. We find that interstate banking deregulation had significant beneficial effects on the quantity and quality of innovation activities, especially for firms highly dependent on external capital and located closer to entering banks. Furthermore, we find that these results are strongly driven by a greater ability of deregulated banks to geographically diversify credit risk.

Journal ArticleDOI
TL;DR: In this article, the physical, transport and electrochemical behaviors of the electrodes made from composites containing carbon nanotubes (CNTs) are discussed, and the challenges that remain in using CNTs and CNT-based composites as well as the prospects for exploiting them in the future are discussed.

Journal ArticleDOI
TL;DR: It is shown that this system generically exhibits a (nonquantized) zero-bias peak even when the wire is topologically trivial and does not possess Majorana end states, by simulating the tunneling conductance for multiband wires with realistic amounts of disorder.
Abstract: One of the simplest proposed experimental probes of a Majorana bound state is a quantized (2e(2)/h) value of zero-bias tunneling conductance. When temperature is somewhat larger than the intrinsic width of the Majorana peak, conductance is no longer quantized, but a zero-bias peak can remain. Such a nonquantized zero-bias peak has been recently reported for semiconducting nanowires with proximity induced superconductivity. In this Letter we analyze the relation of the zero-bias peak to the presence of Majorana end states, by simulating the tunneling conductance for multiband wires with realistic amounts of disorder. We show that this system generically exhibits a (nonquantized) zero-bias peak even when the wire is topologically trivial and does not possess Majorana end states. We make comparisons to recent experiments, and discuss the necessary requirements for confirming the existence of a Majorana state.

Journal ArticleDOI
TL;DR: Aggregation-induced emission (AIE) is a newly developed phenomenon that is exactly opposite to the aggregation-caused emission quenching effect observed with some conventional luminophores as discussed by the authors.

Journal ArticleDOI
TL;DR: A photoanode based on ZnO nanotetrapods, which feature good vectorial electron transport and network forming ability, has been developed for efficient photoelectrochemical water splitting andNitrogen-doping represents the second strategy, which yielded a photocurrent density higher than those of the corresponding nanowire devices reported so far.
Abstract: A photoanode based on ZnO nanotetrapods, which feature good vectorial electron transport and network forming ability, has been developed for efficient photoelectrochemical water splitting. Two strategies have been validated in significantly enhancing light harvesting. The first was demonstrated through a newly developed branch-growth method to achieve secondary and even higher generation branching of the nanotetrapods. Nitrogen-doping represents the second strategy. The pristine ZnO nanotetrapod anode yielded a photocurrent density higher than those of the corresponding nanowire devices reported so far. This photocurrent density was significantly increased for the new photoanode architecture based on the secondary branched ZnO nanotetrapods. After N-doping, the photocurrent density enjoyed an even more dramatic enhancement to 0.99 mA/cm2 at +0.31 V vs Ag/AgCl. The photocurrent enhancement is attributed to the greatly increased roughness factor for boosting light harvesting associated with the ZnO nanotetr...

Journal ArticleDOI
TL;DR: A new generation bioprobe is developed by integrating tetraphenylsilole, a fluorogenic unit with aggregation-induced emission (AIE) characteristic, with cyclic arginine-glycine-aspartic acid tripeptide (cRGD), a targeting ligand to integrin α(v)β(3) receptor.
Abstract: Specific bioprobes with fluorescence turn-on response are highly desirable for high contrast biosensing and imaging. In this work, we developed a new generation bioprobe by integrating tetraphenylsilole, a fluorogenic unit with aggregation-induced emission (AIE) characteristic, with cyclic arginine–glycine–aspartic acid tripeptide (cRGD), a targeting ligand to integrin αvβ3 receptor. Emission of the AIE probe is switched on upon its specific binding to integrin αvβ3, which allows quantitative detection of integrin αvβ3 in solution and real-time imaging of the binding process between cRGD and integrin αvβ3 on cell membrane. The probe can be used for tracking integrin αvβ3 and for identifying integrin αvβ3-positive cancer cells.

Journal ArticleDOI
TL;DR: Support is found for a mediated moderation model demonstrating that social learning mediates the interaction of abusive supervision and power distance on subordinate interpersonal deviance, while ruling out alternate self-regulation impairment or displaced aggression explanations.
Abstract: We predicted that the effects of abusive supervision are likely to be moderated by subordinate power distance orientation and that the nature of the moderating effect will depend on the outcome. Drawing upon work suggesting that high power distance orientation subordinates are more tolerant of super

Posted Content
TL;DR: This paper proposes a regularization formulation for learning the relationships between tasks in multi-task learning, called MTRL, which can also describe negative task correlation and identify outlier tasks based on the same underlying principle.
Abstract: Multi-task learning is a learning paradigm which seeks to improve the generalization performance of a learning task with the help of some other related tasks. In this paper, we propose a regularization formulation for learning the relationships between tasks in multi-task learning. This formulation can be viewed as a novel generalization of the regularization framework for single-task learning. Besides modeling positive task correlation, our method, called multi-task relationship learning (MTRL), can also describe negative task correlation and identify outlier tasks based on the same underlying principle. Under this regularization framework, the objective function of MTRL is convex. For efficiency, we use an alternating method to learn the optimal model parameters for each task as well as the relationships between tasks. We study MTRL in the symmetric multi-task learning setting and then generalize it to the asymmetric setting as well. We also study the relationships between MTRL and some existing multi-task learning methods. Experiments conducted on a toy problem as well as several benchmark data sets demonstrate the effectiveness of MTRL.

Proceedings ArticleDOI
25 Mar 2012
TL;DR: The frequency diversity of the subcarriers in OFDM systems is explored and a novel approach called FILA is proposed, which leverages the channel state information (CSI) to alleviate multipath effect at the receiver, which can significantly improve the localization accuracy compared with the corresponding RSSI approach.
Abstract: Indoor positioning systems have received increasing attention for supporting location-based services in indoor environments. WiFi-based indoor localization has been attractive due to its open access and low cost properties. However, the distance estimation based on received signal strength indicator (RSSI) is easily affected by the temporal and spatial variance due to the multipath effect, which contributes to most of the estimation errors in current systems. How to eliminate such effect so as to enhance the indoor localization performance is a big challenge. In this work, we analyze this effect across the physical layer and account for the undesirable RSSI readings being reported. We explore the frequency diversity of the subcarriers in OFDM systems and propose a novel approach called FILA, which leverages the channel state information (CSI) to alleviate multipath effect at the receiver. We implement the FILA system on commercial 802.11 NICs, and then evaluate its performance in different typical indoor scenarios. The experimental results show that the accuracy and latency of distance calculation can be significantly enhanced by using CSI. Moreover, FILA can significantly improve the localization accuracy compared with the corresponding RSSI approach.