Flexible high-performance graphene hybrid photodetectors functionalized with gold nanostars and perovskites

Hybrid materials in optoelectronic devices can provide synergistic effects that complementarily enhance the properties of each component. Here, flexible high-performance graphene hybrid photodetectors (PDs) are developed by introducing gold nanostars (GNSs) and perovskites for strong light trapping with hot electron transfer and efficient light harvesting characteristics, respectively. While pristine graphene PDs do not exhibit discernible photodetection properties due to the very low photon absorption and ultrafast charge carrier recombination, graphene PDs functionalized with GNSs and a densely covered perovskite layer exhibit outstanding photoresponsive properties with a photoresponsivity (R) of 5.90 x 10(4) A W-1 and a specific detectivity of 1.31 x 10(13) Jones, the highest values among those reported for perovskite-functionalized graphene PDs thus far. Moreover, we fabricated a flexible 10 x 10 PD array that shows well-resolved spatiotemporal mapping of light signals with excellent operational and mechanical stabilities at a bending radius down to 3 mm and in repeated bending tests for over 1000 cycles. Comprehensive analyses using finite-difference time-domain (FDTD) theoretical calculations, scanning near-field optical microscopy, and photoluminescence mapping reveal the effective light trapping effect of GNSs and the charge carrier transfer between the perovskite and graphene. This work provides a new design platform for flexible and high-performance photodetection systems

Subproblem approach for modeling multiply connected thin regions with an h-conformal magnetodynamic finite element formulation

A subproblem h-conformal eddy current finite element method is proposed for correcting the inaccuracies inherent to thin shell models. Such models replace volume thin regions by surfaces but neglect border effects in the vicinity of their edges and corners. The developed surface-to-volume correction problem is defined as a step of the multiple subproblems that can split a complete problem, consisting of inductors and magnetic or conducting regions, some of these being thin regions. The general case of multiply connected thin regions is considered. © 2013 EDP Sciences.status: publishe

Influence of contact resistance on shielding efficiency of shielding gutters for high-voltage cables

The shielding of buried three-phase high-voltage power lines can be done by placing them in conducting ferromagnetic U-shaped gutters covered with plates. In case of a perfect electrical contact between adjacent gutters and between adjacent cover plates, induced currents in the shield efficiently reduce the magnetic field generated by the cables. As however a perfect contact cannot be guaranteed, in practice, it is useful to quantify the effect of a defective electrical contact on the field reduction. From two-dimensional/three-dimensional finite element computations and experiments, the influence of the contact resistance on the shielding efficiency is investigated, as a function of the ratio of axial length to height of the shield elements. Furthermore, the effect of other parameters on the shielding efficiency is studied: the ratio of axial length to height, a parasitic air gap between the gutter and the cover plate and the type of the shield material. It was found that a low contact resistance deteriorates much more the shielding in case of an aluminium shield than in case of a steel shield. As expected, the effect is larger for shield elements with relatively short axial length with regard to the other dimensions. Nevertheless, the effect remains quite significant for aluminium shields with practically convenient dimensions.status: publishe

Effectiveness and safety of in vitro maturation of oocytes versus in vitro fertilisation in women with high antral follicle count: Study protocol for a randomised controlled trial

Introduction: In vitro maturation (IVM) is a potential alternative to conventional in vitro fertilisation (IVF) to avoid ovarian hyperstimulation syndrome (OHSS). This is particularly relevant in women with a high antral follicle count (AFC) and/or polycystic ovary syndrome (PCOS), who are at increased risk for OHSS. However, no randomised controlled trials of IVM versus IVF in women with high AFC have reported both pregnancy and OHSS rates. The aim of this study is to compare the effectiveness and safety of one IVM cycle and one IVF with segmentation cycle within women with PCOS or high AFC-related subfertility. Methods: and analysis: This randomised controlled trial will be conducted at a specialist IVF centre in Vietnam. Eligible subfertile women with PCOS and/or high AFC will be randomised to undergo either IVM or IVF. The primary outcome is live birth after the first embryo transfer of the started treatment cycle. Cycles in which no embryo is available for transfer will be considered as failures. The study has a non-inferiority design, with a maximal acceptable between-group difference of 5%. Rates of OHSS will also be reported. Ethics and dissemination:: Ethical approval was obtained from the participating centre, and informed patient consent was obtained before study enrolment. Results of the study will be submitted for publication in a peer-reviewed journal

Acceptability of and willingness to pay for using a smartphone-based vaccination application in a Vietnamese cohort

Bach Xuan Tran,1,2 Quang N Nguyen,3,4 Anh Kim Dang,5 Giang Thu Vu,4 Vuong Quan Hoang,6 Phuong Viet La,7 Duc Anh Hoang,8 Nhue Van Dam,9 Thu Trang Vuong,10 Long Hoang Nguyen,11 Huong Thi Le,1 Carl A Latkin,2 Cyrus SH Ho,12 Roger CM Ho11,13 1Institute for Preventive Medicine and Public Health, Hanoi Medical University, Hanoi, Vietnam; 2Department of Health, Behavior and Society, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; 3Université Claude Bernard Lyon 1, Villeurbanne 69100, France; 4Center of Excellence in Evidence-based Medicine, Nguyen Tat Thanh University, Ho Chi Minh City 700000, Vietnam; 5Institute for Global Health Innovations, Duy Tan University, Da Nang 550000, Vietnam; 6Centre for Interdisciplinary Social Research, Thanh Tay University, Hanoi, Vietnam; 7Vuong & Associates, Hanoi, Vietnam; 8Gateway International School, Hanoi, Vietnam; 9Faculty of Graduate Studies, National Economics University, Hanoi, Vietnam; 10Sciences Po Paris, Campus de Dijon, Dijon, France; 11Center of Excellence in Behavioral Medicine, Nguyen Tat Thanh University, Ho Chi Minh City 700000, Vietnam; 12Department of Psychological Medicine, National University Hospital, Singapore 119074, Singapore; 13Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119074, Singapore Background: The increasing accessibility of smartphone in Vietnam shows potential in using smartphone applications for vaccination management to improve compliance. However, the acceptability and financial feasibility of using this application in Vietnam have not yet been understood. This study measured the general perception of and willingness to pay (WTP) for using smartphone-based vaccination management applications and their associated factors in Vietnam. Subjects and methods: A cross-sectional study was conducted between March and April 2016 in an urban vaccination clinic at the Hanoi Medical University in Vietnam. Convenience sampling was used to recruit 429 adult participants who had received vaccinations or whose children were vaccinated. Sociodemographic characteristics and the acceptability of and WTP for using smartphone-based vaccination management applications were evaluated. Results: Among participants who used smartphone applications, 5% were aware of existing vaccination management applications, of whom 57.9% had previously used the applications. About 69.6% of participants believed that the applications were necessary, 93.7% of them were also willing to use the applications, and 79.1% were willing to pay 92.7 thousand Vietnamese dong (VND) for the applications on average. Participants who were older, unemployed, earned more household income, and having knowledge about functions and benefits of vaccination were less likely to use the vaccination applications. Participants who brought their children to get vaccinated at younger age and with higher level of education were willing to pay more for vaccination applications. Conclusion: High levels of acceptability of, willingness to use, and WTP for smartphone-based vaccination management applications among Vietnamese participants are reported. Increased education and awareness about the benefits of vaccination and vaccination management applications through community health workers might increase the feasibility of implementing such applications and perception toward their usage among young adult smartphone users. In addition, building a stronger relationship with health care providers at hospitals might improve the application’s visibility and adoption. Keywords: WTP, feasibility, smartphone, vaccine, management, Vietna

Advances in prostaglandin and thromboxane research

Farmers are the key actors of land-use change processes. It is thus essential to choose a suitable architecture for farmer behavior to model such processes. In this paper, we compared three models with different architectures to model the farmer behavior in the coastal areas of the Ben Tre province: (i) The first one is a probabilistic model that allows farmer to select the land-use pattern based on land change probability; (ii) The second model is based on multi-criteria decision making and takes into account the land suitability of the parcel and the farmer benefit; (iii) The third model used a BDI (Beliefs - Desires - Intentions) architecture. For each of these models, we have compared the difference between simulated data and real data by using the Fuzzy Kappa coefficient. The results show the suitability of the BDI architecture to build land-use change model and to support decision-making on land-use planning