Improved properties of Ge MOS capacitors with HfTiON or HfTiO gate dielectric by using wet-NO ge-surface pretreatment

HfTiO/GeOxNy and HfTiON/GeOxNy stack gate dielectrics are prepared by using wet-NO or wet-N2O pretreatment on Ge substrate. Experimental results show that the wet NO pretreatment can lead to excellent interface properties, gate leakage properties and device reliability, especially for the HfTiON/GeOxNy dielectric. The involved mechanisms lie in the roles of N in blocking oxygen diffusion and Ge out-diffusion and suitable N incorporation in the GeO xNy interlayer, which effectively suppress further growth of GeOxNy interlayer and the growth of unstable GeO x during subsequent processing. © 2008 IEEE.published_or_final_versio

Suppressed growth of unstable low-fr GeOx interlayer in Ge metal-oxide-semiconductor capacitor with high-k gate dielectric by annealing in water vapor

The effects of water vapor added in the N2 annealing of high-k HfTiON gate dielectric on Ge metal-oxide-semiconductor capacitor are investigated. Both transmission-electron microscopy and ellipsometry indicate that, as compared to dry-N2 annealing, the wet-N2 annealing can greatly suppress the growth of unstable low-k GeOx at the dielectric/Ge interface, thus resulting in smaller equivalent dielectric thickness, as well as less interface states and dielectric charges. All these are attributed to the hydrolyzable property of GeOx in water. Moreover, the wet-N2 annealed capacitor has ten times lower gate-leakage current due to its better dielectric morphology as confirmed by atomic force microscopy. © 2007 American Institute of Physics.published_or_final_versio

Detecting hate speech on twitter using a convolution-GRU based deep neural network

In recent years, the increasing propagation of hate speech on social media and the urgent need for effective counter-measures have drawn significant investment from governments, companies, as well as empirical research. Despite a large number of emerging scientific studies to address the problem, existing methods are limited in several ways, such as the lack of comparative evaluations which makes it difficult to assess the contribution of individual works. This paper introduces a new method based on a deep neural network combining convolutional and long short term memory networks, and conducts an extensive evaluation of the method against several baselines and state of the art on the largest collection of publicly available datasets to date. We show that our proposed method outperforms state of the art on 6 out of 7 datasets by between 0.2 and 13.8 points in F1. We also carry out further analysis using automatic feature selection to understand the impact of the conventional manual feature engineering process that distinguishes most methods in this field. Our findings challenge the existing perception of the importance of feature engineering, as we show that: the automatic feature selection algorithm drastically reduces the original feature space by over 90% and selects predominantly generic features from datasets; nevertheless, machine learning algorithms perform better using automatically selected features than the original features

Electric Field Effects on Graphene Materials

Understanding the effect of electric fields on the physical and chemical properties of two-dimensional (2D) nanostructures is instrumental in the design of novel electronic and optoelectronic devices. Several of those properties are characterized in terms of the dielectric constant which play an important role on capacitance, conductivity, screening, dielectric losses and refractive index. Here we review our recent theoretical studies using density functional calculations including van der Waals interactions on two types of layered materials of similar two-dimensional molecular geometry but remarkably different electronic structures, that is, graphene and molybdenum disulphide (MoS$_2$). We focus on such two-dimensional crystals because of they complementary physical and chemical properties, and the appealing interest to incorporate them in the next generation of electronic and optoelectronic devices. We predict that the effective dielectric constant ($\varepsilon$) of few-layer graphene and MoS$_2$ is tunable by external electric fields ($E_{\rm ext}$). We show that at low fields ($E_{\rm ext}^{}<0.01$ V/\AA) $\varepsilon$ assumes a nearly constant value $\sim$4 for both materials, but increases at higher fields to values that depend on the layer thickness. The thicker the structure the stronger is the modulation of $\varepsilon$ with the electric field. Increasing of the external field perpendicular to the layer surface above a critical value can drive the systems to an unstable state where the layers are weakly coupled and can be easily separated. The observed dependence of $\varepsilon$ on the external field is due to charge polarization driven by the bias, which show several similar characteristics despite of the layer considered.Comment: Invited book chapter on Exotic Properties of Carbon Nanomatter: Advances in Physics and Chemistry, Springer Series on Carbon Materials. Editors: Mihai V. Putz and Ottorino Ori (11 pages, 4 figures, 30 references

Implementation of a comprehensive intervention for patients at high risk of cardiovascular disease in rural China: A pragmatic cluster randomized controlled trial

Objective: This study aims to assess whether a standard intervention package of cardiovascular disease (CVD) care was being delivered effectively, and if it was associated with improved lifestyle and biomedical indicators. Methods: In rural China, we implemented a pragmatic cluster randomized controlled trial for 12 months, randomized at the township hospital level, and compared with usual care. Intervention case management guideline, training and performance monitoring meeting and patient support activities were designed to fit within the job description of family doctors in the township hospitals and comprised: 1) prescription of a standardised package of medicines targeted at those with hypertension or diabetes; 2) advice about specific lifestyle interventions; and 3) advice about medication adherence. Participants were 50-74 years old, had hypertension and CVD risk scores >20% or diabetes, but were excluded if a history of severe CVD events. We also randomly selected 100 participants from six selected clusters per arm as a panel to collect intermediate biomedical indicators over time. Results: A total of 28,130 participants, in 33 intervention and 34 control township hospitals, were recruited. Compared with the control arm, participants in the intervention arm had substantially improved prescribing rates of anti-hypertensives, statins and aspirin (P0.05). Conclusion: Implementation of the package by family doctors was feasible and improved prescribing and some lifestyle changes. Additional measures such as reducing medication costs and patient education are required. Trial registration: Current Controlled Trials ISRCTN58988083

Review: optical fiber sensors for civil engineering applications

Optical fiber sensor (OFS) technologies have developed rapidly over the last few decades, and various types of OFS have found practical applications in the field of civil engineering. In this paper, which is resulting from the work of the RILEM technical committee “Optical fiber sensors for civil engineering applications”, different kinds of sensing techniques, including change of light intensity, interferometry, fiber Bragg grating, adsorption measurement and distributed sensing, are briefly reviewed to introduce the basic sensing principles. Then, the applications of OFS in highway structures, building structures, geotechnical structures, pipelines as well as cables monitoring are described, with focus on sensor design, installation technique and sensor performance. It is believed that the State-of-the-Art review is helpful to engineers considering the use of OFS in their projects, and can facilitate the wider application of OFS technologies in construction industry

Effect of a training and educational intervention for physicians and caregivers on antibiotic prescribing for upper respiratory tract infections in children at primary care facilities in rural China: a cluster-randomised controlled trial

Background: Inappropriate antibiotic prescribing contributes to the generation of drug resistance worldwide, and is particularly common in China. We assessed the effectiveness of an antimicrobial stewardship programme aiming to reduce inappropriate antibiotic prescribing in paediatric outpatients by targeting providers and caregivers in primary care hospitals in rural China. Methods: We did a pragmatic, cluster-randomised controlled trial with a 6-month intervention period. Clusters were primary care township hospitals in two counties of Guangxi province in China, which were randomly allocated to the intervention group or the control group (in a 1:1 ratio in Rong county and in a 5:6 ratio in Liujiang county). Randomisation was stratified by county. Eligible participants were children aged 2–14 years who attended a township hospital as an outpatient and were given a prescription following a primary diagnosis of an upper respiratory tract infection. The intervention included clinician guidelines and training on appropriate prescribing, monthly prescribing peer-review meetings, and brief caregiver education. In hospitals allocated to the control group, usual care was provided, with antibiotics prescribed at the individual clinician's discretion. Patients were masked to their allocated treatment group but doctors were not. The primary outcome was the antibiotic prescription rate in children attending the hospitals, defined as the cluster-level proportion of prescriptions for upper respiratory tract infections in 2–14-year-old outpatients, issued during the final 3 months of the 6-month intervention period (endline), that included one or more antibiotics. The outcome was based on prescription records and analysed by modified intention-to-treat. This study is registered with the ISRCTN registry, number ISRCTN14340536. Findings: We recruited all 25 eligible township hospitals in the two counties (14 hospitals in Rong county and 11 in Liujiang county), and randomly allocated 12 to the intervention group and 13 to the control group. We implemented the intervention in three internal pilot clusters between July 1, 2015, and Dec 31, 2015, and in the remaining nine intervention clusters between Oct 1, 2015 and March 31, 2016. Between baseline (the 3 months before implementation of the intervention) and endline (the final 3 months of the 6-month intervention period) the antibiotic prescription rate at the individual level decreased from 82% (1936/2349) to 40% (943/2351) in the intervention group, and from 75% (1922/2548) to 70% (1782/2552) in the control group. After adjusting for the baseline antibiotic prescription rate, stratum (county), and potentially confounding patient and prescribing doctor covariates, this endline difference between the groups represented an intervention effect (absolute risk reduction in antibiotic prescribing) of −29% (95% CI −42 to −16; p=0·0002). Interpretation: In China's primary care setting, pragmatic interventions on antimicrobial stewardship targeting providers and caregivers substantially reduced prescribing of antibiotics for childhood upper respiratory tract infections. Funding: Department of International Development (UKAID) through Communicable Diseases Health Service Delivery

Protocol for a pragmatic cluster randomised controlled trial for reducing irrational antibiotic prescribing among children with upper respiratory infections in rural China.

Introduction: Irrational use of antibiotics is a serious issue within China and internationally. In 2012, the Chinese Ministry of Health issued a regulation for antibiotic prescriptions limiting them to <20% of all prescriptions for outpatients, but no operational details have been issued regarding policy implementation. This study aims to test the effectiveness of a multidimensional intervention designed to reduce the use of antibiotics among children (aged 2–14 years old) with acute upper respiratory infections in rural primary care settings in China, through changing doctors’ prescribing behaviours and educating parents/caregivers. Methods and analysis: This is a pragmatic, parallelgroup, controlled, cluster-randomised superiority trial, with blinded evaluation of outcomes and data analysis, and un-blinded treatment. From two counties in Guangxi Province, 12 township hospitals will be randomised to the intervention arm and 13 to the control arm. In the control arm, the management of antibiotics prescriptions will continue through usual care via clinical consultations. In the intervention arm, a provider and patient/caregiver focused intervention will be embedded within routine primary care practice. The provider intervention includes operational guidelines, systematic training, peer review of antibiotic prescribing and provision of health education to patient caregivers. We will also provide printed educational materials and educational videos to patients’ caregivers. The primary outcome is the proportion of all prescriptions issued by providers for upper respiratory infections in children aged 2–14 years old, which include at least one antibiotic. Ethics and dissemination: The trial has received ethical approval from the Ethics Committee of Guangxi Provincial Centre for Disease Control and Prevention, China. The results will be disseminated through workshops, policy briefs, peer-reviewed publications, local and international conferences. Trial registration number: ISRCTN14340536; Pre-results

Integrity of H1 helix in prion protein revealed by molecular dynamic simulations to be especially vulnerable to changes in the relative orientation of H1 and its S1 flank

In the template-assistance model, normal prion protein (PrPC), the pathogenic cause of prion diseases such as Creutzfeldt-Jakob (CJD) in human, Bovine Spongiform Encephalopathy (BSE) in cow, and scrapie in sheep, converts to infectious prion (PrPSc) through an autocatalytic process triggered by a transient interaction between PrPC and PrPSc. Conventional studies suggest the S1-H1-S2 region in PrPC to be the template of S1-S2 $\beta$-sheet in PrPSc, and the conformational conversion of PrPC into PrPSc may involve an unfolding of H1 in PrPC and its refolding into the $\beta$-sheet in PrPSc. Here we conduct a series of simulation experiments to test the idea of transient interaction of the template-assistance model. We find that the integrity of H1 in PrPC is vulnerable to a transient interaction that alters the native dihedral angles at residue Asn$^{143}$, which connects the S1 flank to H1, but not to interactions that alter the internal structure of the S1 flank, nor to those that alter the relative orientation between H1 and the S2 flank.Comment: A major revision on statistical analysis method has been made. The paper now has 23 pages, 11 figures. This work was presented at 2006 APS March meeting session K29.0004 at Baltimore, MD, USA 3/13-17, 2006. This paper has been accepted for pubcliation in European Biophysical Journal on Feb 2, 200