bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Prevalence and Pattern of Risky Sexual Behaviour among Secondary School Adolescents in Yenagoa Local Government Area, Nigeria
Authors: Gregory Frances , Joboy-Okei Evi , Peterside Oliemen 
Published: November 2024

Aim: To determine the prevalence, pattern and socio-demographic factors associated with risky sexual behaviour (RSB) among adolescents in secondary schools in Yenagoa LGA, Bayelsa state.
Study Design: A cross-sectional analytical study.
Place and duration: Yenagoa Local Government Area in Bayelsa state. The study was conducted in March/April 2021.
Methodology: The study utilized self-administered questionnaires among 750 secondary school adolescents selected via multistage sampling. The proportion of adolescents with RSB and the socio-demographic determinants of RSB were analysed using Chi-square test and binary logistic regression with significance level set at p-value=0.05.
Results: Of the 739 responses analysed, the prevalence of RSB was 156 (21.1%) and the mean age at sexual debut was 13.42±2.62 years. All sexually exposed adolescents had an early sexual debut, 23.7% had multiple sexual partners, and 98.1% reported inconsistent use of condoms. Transactional sex and sexual intercourse after alcohol/illicit drug use occurred in 56.4% and 15.4% of them, respectively. The predictors of RSB were attending a public school (AOR:2.046, 95%CI:1.243 to 3.368), peer pressure (AOR:10.451, 95%CI:6.460 to 16.909), difficulty in communicating with mother (AOR:2.050, 95%CI:1.203 to 3.493) and low maternal education (primary:AOR:2.834, 95%CI:1.300 to 6.181; and secondary: AOR:2.067, 95%CI:1.139 to 3.753). However, age below 18years (10-13years: AOR:0.194, 95%CI:0.051 to 0.741 and 14-17years: AOR:0.259, 95% CI:0.081 to 0.832) was protective of RSB.
Conclusion: RSB is high among adolescents attending secondary schools in Yenagoa. Sex education, peer-based programmes and parent-adolescent communications should be encouraged to reduce the prevalence of RSB among adolescents.
Quantitative analysis of sensitivity to a Wnt3a gradient in determination of the pole‐to‐pole axis of mitotic cells by using a microfluidic device
Authors: Hiraiwa Takumi , Nakai Yuichiro , Yamada Takahiro G. , Tanimoto Ryuichi , Kimura Hiroshi , Matsumoto Yoshinori , Miki Norihisa , Hiroi Noriko , Funahashi Akira 
Published: September 2018

Proper determination of the cell division axis is essential during development. Wnt3a is a known regulator of the cell division axis; however, the sensitivity of cells to Wnt3a signalling and its role in determining the cell division axis have not been measured to date. To address this gap, we took advantage of the asymmetric distribution of outer dense fibre 2 (ODF2/cenexin) proteins on centrosomes in dividing cells. To precisely quantify the sensitivity of cells to Wnt3a signalling, we developed a microfluidic cell culture device, which can produce a quantitative gradient of signalling molecules. We confirmed that mitotic SH‐SY5Y neuroblastoma cells could detect a 2.5 ~ 5 × 10−3 nm·μm−1 Wnt3a concentration gradient and demonstrated that this gradient is sufficient to affect the determination of the pole‐to‐pole axis of cell division during the later stages of mitosis.
Chassis Modeling and Optimization by the Advanced Method
ABE
Authors: Albers Ingo 
Published: September 2018

Abstract

The design of suspensions for cars is mostly driven by experience. The other method is to use a commercially available simulation tool, which delivers the characteristic data of a suspension, defined by connection points and elasticities. The user is not really involved in the solution of the problem. This chapter gives hints for a rather simple method to find reasonable chassis designs with short computational efforts. There are equations available, which can be solved with Excel on a normal
PC
. Even elastic suspension parts can be regarded and the effects of tolerances can be evaluated. The chapter gives guidance for setting up such simple simulation programs. For more detailed information, the literature may be used.
Micro, Mild, and Full Hybrids
Authors: Pels Thomas , Kaup Carsten 
Published: September 2018

Abstract
This article classifies hybrid vehicles into micro, mild and full hybrids based on powertrain functionalities. All hybrid powertrain functions can be allocated to three functional groups: Energy management, torque management and electric propulsion. Micro hybrid functionalities are related to energy management only whereas mild hybrids cover energy management and torque management. Powertrain functions out of all three groups are relevant for full hybrids. The basic functionalities are described in detail and examples of various hybrid powertrain architectures are outlined. This incorporates parallel, serial and power split configurations. Finally the impact of the architecture and the technical solution on the classification of hybrids is discussed.
EVPowertrain Parameters
Authors: Chau K.T. 
Published: September 2018

AbstractThe electric vehicle (EV) powertrain is fundamentally different from the internal combustion engine vehicle (ICEV) powertrain. It is mainly due to the difference in the production of driving force, one is from the electric motor and one is from the combustion engine. Thus, the parameters of theEVpowertrain cannot inherit from theICEVpowertrain. As the electric motor is the key component of theEVpowertrain, the parameters of the electric motor can be extended to the wholeEVpowertrain. Additionally, as the electric motor requirements forEVpropulsion are very different from that for industrial application, some parameters of the electric motor are unique toEVpowertrain such as the efficiency map, the intermittent power, and the driving‐cycle power.
Traction DriveCVT
Authors: Tanaka Hirohisa 
Published: September 2018

AbstractTraction driveCVTtransmits tangential force through glass‐transitioned thin film by applying highly pressurized contact force. Scientific approaches for estimating traction force, sideslip force for speed ratio change, and spin on the patch are described using traction fluid rheological model; features of full‐ and half‐toroidalCVTsare compared including speed ratio changing mechanism. Endurance of traction drive rolling elements is also discussed by showingS − Ncurves and photo of a running track. Finally, a cross‐sectional view of a half‐toroidalCVTfor3Lturbo‐gasolineFRcar with387 Nmtorque capacity come on to the market in 1999 is shown.
Surface‐Confined Fabrication of Ultrathin Nickel Cobalt‐Layered Double Hydroxide Nanosheets for High‐Performance Supercapacitors
Authors: Yang Juan , Yu Chang , Hu Chao , Wang Man , Li Shaofeng , Huang Huawei , Bustillo Karen , Han Xiaotong , Zhao Changtai , Guo Wei , Zeng Zhiyuan , Zheng Haimei , Qiu Jieshan 
Published: September 2018

AbstractThe design and fabrication of 2D nanostructure electrodes with desired electrochemical activities is highly demanded for electrocatalysis and supercapacitors. Herein, the tuned fabrication of ultrathin and tortuous nickel/cobalt‐layered double hydroxide (NiCo‐LDH) nanosheets via a graphene oxide (GO) surface‐confined strategy is reported, yielding nanosheets with a thickness of 1.7–1.8 nm that is duplicated from the graphene oxides in terms of both the lateral size and the shape. It has been found that the C/O functional groups on the GO surface have functioned to promote the oxidation of Co2+ to Co3+, and to transform the β‐phase NiCo‐hydroxide (NiCo‐OH) into the LDH‐phase with tuned homogenous composition and geometry. The ultrathin NiCo‐LDH nanosheets mimic the morphology and size of the graphene due to the surface‐confined and/or surface‐guided growth. The as‐obtained NiCo‐LDH‐graphene (NiCo‐LDH‐G) nanosheets exhibit a superior electrocatalytic activity for oxygen evolution reaction, evidenced by a small overpotential of 0.337 V (@10 mA cm−2 in 0.1 m KOH electrolyte), and a high charge storage capability of 1489 F g−1 as electrodes for supercapacitors. This 2D surface‐confined growth strategy may pave a way for the fabrication of ultrathin 2D materials including but not limited to transition metal hydroxides for high‐performance electrochemical applications.
Self‐Assembly of Cellulose Nanocrystals into Semi‐Spherical Photonic Cholesteric Films
Authors: Rofouie Pardis , Alizadehgiashi Moien , Mundoor Haridas , Smalyukh Ivan I. , Kumacheva Eugenia 
Published: September 2018

AbstractSpherical‐shape cholesteric (Ch) photonic films offer promising applications such as omnidirectional lasing and broadband reflection. Here, a strategy is reported for the fabrication of photonic Ch films by the self‐assembly of cellulose nanocrystals (CNCs) in semi‐spherical cavities. It is shown that film structure and photonic properties are controlled by the film curvature, the composition of the precursor CNC suspension, and its liquid crystalline or isotropic state. The effect of curvature of the drying Ch‐CNC films coupled with the restricted mobility of CNCs during film preparation results in the variation in pitch and helical axis inclination, thus leading to broadband reflectance properties of the films. The role of curvature of the Ch‐CNC films is underlined by comparing their distinct properties with those of planar films with the same composition. These findings provide a novel insight into the design and development of biomimetic photonic Ch films.
Enhanced Biological Photosynthetic Efficiency Using Light‐Harvesting Engineering with Dual‐Emissive Carbon Dots
Authors: Li Wei , Wu Shuangshuang , Zhang Haoran , Zhang Xuejie , Zhuang Jianle , Hu Chaofan , Liu Yingliang , Lei Bingfu , Ma Li , Wang Xiaojun 
Published: September 2018

AbstractEnhancing solar energy conversion is imperative and maximizing solar energy capture remains significant. Here, nanotechnology toward engineering hybrid photosystem involving biological photosynthetic chloroplasts and dual‐emissive carbon dots (CDs) is employed for improved photosynthesis by harnessing more effective light. Specifically, the as‐prepared CDs show strong absorption in ultraviolet (UV) light region and exhibit intense blue and red light in water, which exactly match the absorption spectrum of chloroplasts. After coating the CDs on the surface of extracted chloroplasts, the hybrid photosystem produces 2.8 times more adenosine triphosphate (ATP) than chloroplasts themselves in vitro. Moreover, CD‐induced enhancement of photosynthesis in living plant is proved as well, showing a maximum increase of 25% in electron transport rates over the leaves without CDs, demonstrating the effective nanobionics engineering of plant performance in vivo. This is the first report on employing the unique dual‐emission trait of nanoparticles, especially the red emission, to augment photoabsorption of both extracted chloroplasts and intact leaves for enhanced photosynthetic properties. This work provides a promising strategy for engineering biological photosynthetic system with dual‐emissive CDs to enhance solar energy conversion both in vivo and in vitro, and promotes the development in the field of nanobionic.
Organic‐Single‐Crystal Vertical Field‐Effect Transistors and Phototransistors
Authors: Liu Jinyu , Zhou Ke , Liu Jie , Zhu Jia , Zhen Yonggang , Dong Huanli , Hu Wenping 
Published: September 2018

AbstractOrganic vertical field‐effect transistors (VFETs) have attracted significant attention over the past years due to their unique characteristics of high output currents, low operation voltages, high working frequency, and promising high‐density integration for circuits. However, most currently reported VFETs demonstrate poor performance, e.g., with low on/off ratio and current density. Here, the first organic‐single‐crystal vertical field‐effect transistors (SC‐VFETs) and phototransistors are constructed from 2,6‐diphenyl anthracene (DPA) through a modified method. The devices exhibit high on/off ratio of 106 and a high current density of 100 mA cm‐2 under a small voltage of −5 V, which are proved to be one of the best performances for organic VFETs. Furthermore, superior photoresponse performance with photoresponsivity of 110 A W‐1 and detectivity of 1013 Jones is obtained under light illumination for vertical phototransistors. These results confirm the control of the intrinsic Schottky barrier height at the graphene–DPA junction along with good interfacial contact effectively suppressing the dark current to realize a large on/off ratio and high light detectivity. This vertical integration of graphene with organic single crystals via simple, effective fabrication processes opens up new opportunities to realize high‐performance integrated organic vertical electronic and optoelectronic devices.
A Fused Ring Electron Acceptor with Decacyclic Core Enables over 13.5% Efficiency for Organic Solar Cells
Authors: He Dan , Zhao Fuwen , Xin Jingming , Rech Jeromy James , Wei Zhixiang , Ma Wei , You Wei , Li Bao , Jiang Li , Li Yongfang , Wang Chunru 
Published: September 2018

AbstractExtending π‐conjugation of donor units in fused ring electron acceptors (FREAs) promises to reinforce intramolecular charge transfer for smaller bandgaps, and enhances intermolecular interactions for higher charge mobility. Despite these advantages, power conversion efficiencies (PCEs) of FREAs with a large planar donor core are still below 12%. Herein, a fused decacyclic donor unit, IDC, is developed, and the FREA, IDCIC, whose optical bandgap is 1.45 eV, is synthesized. The FTAZ:IDCIC‐based organic solar cell (OSC) with a binary additive, chloronaphthalene and 1,8‐diiodooctane (CN&DIO), affords a remarkable PCE of 13.58%, which is among the highest efficiencies of OSCs. The binary additive plays a crucial role in the morphology of FTAZ:IDCIC‐based OSCs. The addition of DIO promotes IDCIC to aggregate and enhances domain size and domain purity in FTAZ:IDCIC blend film for its poor solubility in DIO, while the addition of chloronaphthalene (CN) inhibits the aggregation, facilitates IDCIC to diffuse into the donor, and reduces domain size and domain purity for its excellent solubility in CN. The binary additive, CN&DIO, compromises the effect of the two; thus FTAZ:IDCIC‐based OSCs with 0.25% CN&DIO obtain moderate domain size and high domain purity simultaneously, achieving the least charge recombination for the highest JSC (21.98 mA cm−2) and fill factor (FF) (71.03%).
Toward an Ethical Reflective Practice of a Theory in the Flesh: Embodied Subjectivities in a Youth Participatory Action Research Mural Project
Authors: Fernández Jesica Siham 
Published: September 2018

AbstractThe focus of this paper is to demonstrate how embodied subjectivities shape research experiences. Through an autoethnography of my involvement in a Youth Participatory Action Research (YPAR) after‐school program with low‐income and working‐class youth of Color from predominantly Latinx communities I examined my embodied subjectivities, via an ethical reflective practice, as these surfaced in the research context. Autoethnography is presented as a tool to facilitate an ethical reflective practice that aligns with heart‐centered work. Drawing from an epistemology of a theory in the flesh (Anzaldúa & Moraga, 1981), embodied subjectivities are defined by the lived experiences felt and expressed through the body, identities, and positionalities of the researcher. The article concludes with implications for the development of community psychology competencies that attend to the researcher's embodied subjectivities.
Synthesis of Aryl‐ and Heteroaryl‐Trifluoroethyl Ethers: Aims, Challenges and New Methodologies
Authors: Pethő Bálint , Novák Zoltán 
Published: September 2018

AbstractFluorinated substances have outstanding importance in most fields of the chemical industry, from agrochemicals and material science to pharmaceutical research. Although aryl‐ and heteroaryl‐trifluoroethyl ethers have widespread applications, predominantly as drug molecules, their preparation was limited to classical synthetic methodologies until the last decade. The transition metal catalyzed cross coupling reactions offered novel synthetic approaches for the facile access of trifluoroethoxylated aromatic compounds. The aim of this review is to give a good overview on recent advances in the synthesis of aryl‐trifluoroethyl ethers from a practical point of view for synthetic organic chemists working in the field of pharmaceutical industry and academia.
[18F]Fluorine‐Labeled Pharmaceuticals: Direct Aromatic Fluorination Compared to Multi‐Step Strategies
Authors: Krüll Jasmin , Heinrich Markus R. 
Published: September 2018

AbstractPositron emission tomography (PET) presents an important tool for medicinal and pharmaceutical investigations, with applications ranging from fundamental research to the diagnosis of a broad variety of diseases. Crucial for the use of this technique is, however, a robust labeling strategy for the preparation of the required radiolabeled compound. For 18‐fluorine‐labeling, which represents the most widely applied method in this field, it is interesting to note that a kind of paradigm change occurred over the last years. While multi‐step labeling strategies were the preferred approach for many decades, mainly due to the lack of suitable leaving groups for direct [18F]fluorination reactions, the synthetic tools to achieve the highly attractive direct 18‐fluorine‐labeling rapidly increased recently. This focus review points out a comparison between the multi‐step approaches and the newly developed direct fluorination strategies available for nucleophilic 18‐fluorination of carbocyclic aromatic systems, including a discussion of advantages and limitations.
Liquid‐Phase Synthesis of Boron Isocyanates: Precursors to Boron Nanoparticles
Authors: Zhu Yinghuai , Hosmane Narayan S 
Published: September 2018

AbstractThe practical application of boron isocyanates has been hindered by their extremely high sensitivity and reactivity toward air and moisture. A convenient synthetic method in a suitable liquid media is reported for practical utilization of boron isocyanates. According to NMR studies, the in situ generated boron isocyanates can be stored for at least one month under an inert atmosphere at −20 °C without noticeable decomposition. The boron tri(isocyanate) (B(NCO)3) was converted into boron nanoparticles by reduction with hydrogen under mild reaction conditions.
Enantioselective Carbonyl Catalysis Enabled by Chiral Aldehydes
Authors: Wang Qiang , Gu Qing , You Shu‐Li 
Published: September 2018

AbstractOrganocatalytic methods have achieved spectacular advancements for the preparation of chiral molecules in highly enantioenriched forms. The fast development of this field can mainly be attributed to the evolution of general and reliable activation modes. The discovery and identification of new activation modes are therefore highly desirable to push the boundaries of asymmetric reactions. In this Minireview, recent advances in enantioselective carbonyl catalysis, one useful subbranch of organocatalysis for the efficient activation of simple amines, will be summarized. With elegantly designed chiral aldehyde catalysts, highly enantioselective and efficient asymmetric reactions can be developed. Continued development of enantioselective carbonyl catalysis is expected in the future.
Priority areas for conservation within four freshwater ecoregions in South America: A scale perspective based on freshwater crabs (Anomura, Aeglidae)
Authors: Gonçalves Alberto S. , Costa Gabriel C. , Bond‐Buckup Georgina , Bartholomei‐Santos Marlise L. , Santos Sandro 
Published: September 2018

Abstract

Although freshwater ecosystems contain high biodiversity and provide valuable ecosystem services, they are severely threatened worldwide. Many broad‐scale approaches to conserve freshwater environments have been proposed, but as headwaters tend to host higher levels of biodiversity, identifying priority areas for conservation at a local scale is essential.
An integrative three‐step framework is proposed to recognize such areas, using anomuran crabs of the family Aeglidae as biodiversity indicator taxa, within four freshwater ecoregions in South America. First, the knowledge on the distribution of species occurring within the study area was updated and the species conservation status assessed. Second, species distribution modelling was used to identify areas of high richness and endemism. Third, these areas were compared with the existing protected area network, in addition to land‐use and urban information, to indicate priority areas for conservation within four freshwater ecoregions (Laguna dos Patos, Upper Uruguay, Lower Uruguay, Tramandaí and Mampituba) studied at a local scale.
Analysis of the distribution of species of the genus Aegla showed that the present protected area network poorly covers freshwater habitats within the study region. Three priority areas for conservation were identified, with high levels of endemism and richness of aeglid species. These areas are mainly located close to current protected areas, and we suggest, therefore, that the enlargement of some protected areas, through the establishment of corridors, would better protect several species with distributions restricted to headwaters, such as macroinvertebrates and fishes, some of which are threatened with extinction.
Use of chronic total occlusion percutaneous coronary intervention techniques for treating acute vessel closure
Authors: Shaukat Arslan , Mooney Michael , Burke M. Nicholas , Brilakis Emmanouil S. 
Published: September 2018

AbstractAcute vessel closure due to dissection is a known complication of percutaneous coronary intervention and can be challenging to treat, especially if guidewire position is lost. Re‐entering into the distal true lumen is commonly done during chronic total occlusion interventions, as part of antegrade dissection strategies. We report two cases of acute vessel closure and guidewire position loss in which the Stingray LP system was successfully used to advance a guidewire into the distal true lumen and recanalize the occluded vessel.
Youngest presenting patient with dystonia 24 and review of the literature
Authors: Nelin Sarah , Hussey Richard , Faux Brian M. , Rohena Luis 
Published: September 2018

Key Clinical MessageDystonia 24 was first reported in 2000 as an autosomal dominant cause of dystonia caused by variants in the ANO3 gene. Although many adults have been described with dystonia 24, since 2014, an increasing number of children have also been reported. Dystonia 24 should also be considered in the differential of a child with unexplained dystonia.
Stereoselective Synthesis of Borylated 1,3‐Dienes by Synergistic Cu/Pd Catalysis
Authors: Vázquez‐Galiñanes Nuria , Fañanás‐Mastral Martín 
Published: September 2018

AbstractA Cu/Pd‐catalyzed alkenylboration of alkynes with alkenyl bromides and bis(pinacolato)diboron is reported. This transformation features the generation of a catalytic β‐boryl‐substituted C(sp2)‐Cu intermediate and subsequent Pd‐catalyzed cross‐coupling. The reaction tolerates a wide array of substrates and affords diversely substituted syn‐borylated 1,3‐dienes under mild conditions with total regio‐ and stereocontrol.
A Stabilized Bisphosphanylsilylene and Its Heavier Congeners
Authors: Kargin Denis , Kelemen Zsolt , Krekić Kristijan , Nyulászi László , Pietschnig Rudolf 
Published: September 2018

AbstractA bisphosphanylsilylene with [3]ferrocenophane backbone and its heavier analogues are described in the form of donor adducts. These heterocarbenes can be formed by dehydrochlorination (Si) or cycloreversion (Sn, Pb) using NHC (N‐heterocyclic carbene) tetramethylimidazol‐2‐ylidene. The structures of the bisphosphanyl‐silylene, ‐stannylene and ‐plumbylene NHC adducts are presented, and the bonding and stability of these compounds were elucidated using DFT calculations. Reactivity studies confirm the stability of the silylene adduct, where the electrophilic character of the silylene center is comparable to a borane.