bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organ doses evaluation for chest computed tomography procedures with TL dosimeters: Comparison with Monte Carlo simulations
Authors: Giansante Louise , Martins Juliana C. , Nersissian Denise Y. , Kiers Karen C. , Kay Fernando U. , Sawamura Marcio V. Y. , Lee Choonsik , Gebrim Eloisa M. M. S. , Costa Paulo R. 
Published: December 2018

AbstractPurposeTo evaluate organ doses in routine and low‐dose chest computed tomography (CT) protocols using an experimental methodology. To compare experimental results with results obtained by the National Cancer Institute dosimetry system for CT (NCICT) organ dose calculator. To address the differences on organ dose measurements using tube current modulation (TCM) and fixed tube current protocols.MethodsAn experimental approach to evaluate organ doses in pediatric and adult anthropomorphic phantoms using thermoluminescent dosimeters (TLDs) was employed in this study. Several analyses were performed in order to establish the best way to achieve the main results in this investigation. The protocols used in this study were selected after an analysis of patient data collected from the Institute of Radiology of the School of Medicine of the University of São Paulo (InRad). The image quality was evaluated by a radiologist from this institution. Six chest adult protocols and four chest pediatric protocols were evaluated. Lung doses were evaluated for the adult phantom and lung and thyroid doses were evaluated for the pediatric phantom. The irradiations were performed using both a GE and a Philips CT scanner. Finally, organ doses measured with dosimeters were compared with Monte Carlo simulations performed with NCICT.ResultsAfter analyzing the data collected from all CT examinations performed during a period of 3 yr, the authors identified that adult and pediatric chest CT are among the most applied protocol in patients in that clinical institution, demonstrating the relevance on evaluating organ doses due to these examinations. With regards to the scan parameters adopted, the authors identified that using 80 kV instead of 120 kV for a pediatric chest routine CT, with TCM in both situations, can lead up to a 28.7% decrease on the absorbed dose. Moreover, in comparison to the standard adult protocol, which is performed with fixed mAs, TCM, and ultra low‐dose protocols resulted in dose reductions of up to 35.0% and 90.0%, respectively. Finally, the percent differences found between experimental and Monte Carlo simulated organ doses were within a 20% interval.ConclusionsThe results obtained in this study measured the impact on the absorbed dose in routine chest CT by changing several scan parameters while the image quality could be potentially preserved.
A novel VRK1 mutation associated with recessive distal hereditary motor neuropathy
Authors: Feng Shu‐Yan , Li Liu‐Yi , Feng Shu‐Man , Zou Zhang‐Yu 
Published: December 2018

AbstractVaccinia‐related kinase 1 (VRK1) mutations can cause motor phenotypes including axonal sensorimotor neuropathy, distal hereditary motor neuropathy (dHMN), spinal muscular atrophy, and amyotrophic lateral sclerosis. Here, we identify a novel homozygous VRK1 p.W375X mutation causing recessive dHMN. The proband presented with juvenile onset of weakness in the distal lower extremities, slowly progressing to the distal upper limbs, with bilateral pes cavus and no upper motor or sensory neuron involvement. Nerve conduction studies showed a pure motor axonal neuropathy. Our findings extend the ethnic distribution of VRK1 mutations, indicating that these mutations should be included in genetic diagnostic testing for dHMN.
Photonics and Optoelectronics with Bacteria: Making Materials from Photosynthetic Microorganisms
Authors: Milano Francesco , Punzi Angela , Ragni Roberta , Trotta Massimo , Farinola Gianluca M. 
Published: December 2018

AbstractA critical selection of the recent literature reports on the use of photosynthetic and photoresponsive bacteria as a source of materials for optoelectronics and photonic devices is discussed, together with the applications foreseen in solar energy conversion and storage and light information technologies. The use of both photoactive cellular components and entire living cells is reviewed, aiming to highlight the great conceptual impact of these studies. These studies point out possible deep changes in the paradigm of design, and synthesis of materials and devices for optoelectronics. Although the possible technological impact of this technology is still hard to be predicted, these studies advance the understanding of photonics of living organisms and develop new intriguing concepts in biomaterials research.
Disordered Structures in Biology Can Provide Material Properties not Obtained with Precise Hierarchy
Authors: Metzler Rebecca A. , Barthelat Francois , Wilker Jonathan J. 
Published: December 2018

AbstractBiological organisms exist in an astounding array of habitats. The materials produced by these organisms correspondingly exhibit significant diversity in function and form. Highly ordered and structured biological materials have been the subject of intense scientific investigation, especially in the context of exploring possible models for functional materials. Biological materials lacking in organized structure, on the other hand, such as barnacle exoskeletons, have largely been ignored. Here disordered biological materials falling into four different classes are discussed: soft and organic, hard and organic, soft and a composite of organic and inorganic, and hard and a composite of organic and inorganic. Across the examples within each class of materials one can see disorder at different length scales providing increases in fracture resistance or flexibility, suggesting disordered biological materials have much to teach us in terms of materials design.
Ultrafast Electrochemical Trigger Drug Delivery Mechanism for Nanographene Micromachines
Authors: Khezri Bahareh , Beladi Mousavi Seyyed Mohsen , Krejčová Ludmila , Heger Zbyněk , Sofer Zdeněk , Pumera Martin 
Published: December 2018

AbstractNano/micromachines with autonomous motion are the frontier of nanotechnology and nanomaterial research. These self‐propelled nano/micromachines convert chemical energy obtained from their surroundings to propulsion. They have shown great potential in diagnostic and therapeutic applications. This work introduces a high‐speed tubular electrically conductive micromachine based on reduced nanographene oxide (n‐rGO) as a platform for drug delivery and platinum (Pt) as the catalytic inner layer. n‐rGO/Pt micromachines are loaded with doxorubicin (DOX) by a simple physical adsorption with a very high loading efficiency, displaying single‐ or multistrand wrapping of DOX monomers on the micromachine cylinders. More importantly, it is found that electron injection into DOX@n‐rGO/Pt micromachines via electrochemistry leads to expulsion of DOX from micromachines in motion within only a few seconds. An in vitro study confirms this efficient release mechanism in the presence of cancerous cells. The unique properties of the n‐rGO/Pt micromotor enable the effective management of DOX release at the tumor site and thus enhances the therapeutic efficiency and reduces the side toxicity toward the healthy tissue. These micromachine drug carriers combine the high loading capacity of conventional carbon‐based drug carriers with a fast and efficient electrochemical drug‐release mechanism.
Mg3+δSbxBi2−x Family: A Promising Substitute for the State‐of‐the‐Art n‐Type Thermoelectric Materials near Room Temperature
Authors: Shu Rui , Zhou Yecheng , Wang Qi , Han Zhijia , Zhu Yongbin , Liu Yong , Chen Yuexing , Gu Meng , Xu Wei , Wang Yu , Zhang Wenqing , Huang Li , Liu Weishu 
Published: December 2018

AbstractThe Bi2Te3−xSex family has constituted n‐type state‐of‐the‐art thermoelectric materials near room temperature (RT) for more than half a century, which dominates the active cooling and novel heat harvesting application near RT. However, the drawbacks of a brittle nature and Te‐content restricts the possibility for exploring potential applications. Here, it is shown that the Mg3+δSbxBi2−x family ((ZT)avg = 1.05) could be a promising substitute for the Bi2Te3−xSex family ((ZT)avg = 0.9–1.0) in the temperature range of 50–250 °C based on the comparable thermoelectric performance through a synergistic effect from the tunable bandgap using the alloy effect and the suppressible Mg‐vacancy formation using an interstitial Mn dopant. The former is to shift the optimal thermoelectric performance to near RT, and the latter is helpful to partially decouple the electrical transport and thermal transport in order to get an optimal RT power factor. The positive temperature dependence of the bandgap suggests this family is also a superior medium‐temperature thermoelectric material for the significantly suppressed bipolar effect. Furthermore, a two times higher mechanical toughness, compared with the Bi2Te3−xSex family, allows for a promising substitute for state‐of‐the‐art n‐type thermoelectric materials near RT.
Large‐Area Organic Solar Cells: Material Requirements, Modular Designs, and Printing Methods
Authors: Wang Guodong , Adil Muhammad Abdullah , Zhang Jianqi , Wei Zhixiang 
Published: December 2018

AbstractThe printing of large‐area organic solar cells (OSCs) has become a frontier for organic electronics and is also regarded as a critical step in their industrial applications. With the rapid progress in the field of OSCs, the highest power conversion efficiency (PCE) for small‐area devices is approaching 15%, whereas the PCE for large‐area devices has also surpassed 10% in a single cell with an area of ≈1 cm2. Here, the progress of this fast developing area is reviewed, mainly focusing on: 1) material requirements (materials that are able to form efficient thick active layer films for large‐area printing); 2) modular designs (effective designs that can suppress electrical, geometric, optical, and additional losses, leading to a reduction in the PCE of the devices, as a consequence of substrate area expansion); and 3) printing methods (various scalable fabrication techniques that are employed for large‐area fabrication, including knife coating, slot‐die coating, screen printing, inkjet printing, gravure printing, flexographic printing, pad printing, and brush coating). By combining thick‐film material systems with efficient modular designs exhibiting low‐efficiency losses and employing the right printing methods, the fabrication of large‐area OSCs will be successfully realized in the near future.
Recent Advances in Energetics and Stability of Metal Halide Perovskites for Optoelectronic Applications
Authors: Yang Jian‐Ming , Luo Yuxin , Bao Qinye , Li Yan‐Qing , Tang Jian‐Xin 
Published: December 2018

AbstractMetal halide perovskites are emerging as a new class of photoactive materials for next‐generation optoelectronics in recent years due to their unique optical and electronic properties. Regardless of significant progress on high‐performance perovskite‐based devices, it is of paramount importance to unveiling the interface energetics, which are crucial for the photon‐harvesting process and energy loss in the layered device configuration. In addition, the stability issue of perovskite materials and related devices has severely hindered their practical application. Herein, the recent advances in the interrelation between perovskite composition, electronic structure, and stability are reviewed. The interface energetics and band alignment with adjacent transport layers, as well as deterioration mechanisms, are addressed in terms of internal composition and external environmental factors. The strategies to improve the device efficiency and durability with interface modification are also discussed. The comprehensive microscopic understandings and precise control of electronic structures and degradation pathways exhibit great potential toward higher‐performance perovskite‐based optoelectronic devices.
Enhanced Oxygen Evolution Reaction Activity of Nanoporous SnO2/Fe2O3/IrO2 Thin Film Composite Electrodes with Ultralow Noble Metal Loading
Authors: Haschke Sandra , Zhuo Ying , Schlicht Stefanie , Barr Maïssa K. S. , Kloth Ricarda , Dufond Maxime E. , Santinacci Lionel , Bachmann Julien 
Published: December 2018

AbstractA conductive SnO2 layer and small quantities of IrO2 surface cocatalyst enhance the catalytic efficiency of nanoporous Fe2O3 electrodes in the oxygen evolution reaction at neutral pH. Anodic alumina templates are therefore coated with thin layers of SnO2, Fe2O3, and IrO2 by atomic layer deposition. In the first step, the Fe2O3 electrode is modified with a conductive SnO2 layer and submitted to different postdeposition thermal treatments in order to maximize its catalytic performance. The combination of steady‐state electrolysis, electrochemical impedance spectroscopy, X‐ray crystallography, and X‐ray photoelectron spectroscopy demonstrates that catalytic turnover and e− extraction are most efficient if both layers are amorphous in nature. In the second step, small quantities of IrO2 with extremely low iridium loading of 7.5 µg cm−2 are coated on the electrode surface. These electrodes reveal favorable long‐term stability over at least 15 h and achieve maximized steady‐state current densities of 0.57 ± 0.05 mA cm−2 at η = 0.38 V and pH 7 (1.36 ± 0.10 mA cm−2 at η = 0.48 V) in dark conditions. This architecture enables charge carrier separation and reduces the photoelectrochemical water oxidation onset by 300 mV with respect to pure Fe2O3 electrodes of identical geometry.
N Doped Carbon Dot Modified WO3 Nanoflakes for Efficient Photoelectrochemical Water Oxidation
Authors: Kong Weiqian , Zhang Xiaofan , Liu Shuangshuang , Zhou Yannan , Chang Binbin , Zhang Shouren , Fan Hongbo , Yang Baocheng 
Published: December 2018

AbstractIt is a serious challenge to develop photoanodes with fast charge separation efficiency and surface reaction kinetics. Herein, the N doped carbon dot modified WO3 nanoflake (NCDs/WO3) is constructed by impregnation method. The resulting NCDs/WO3 exhibits an excellent photocurrent density of 1.42 mA cm−2 (1.0 V vs saturated calomel electrode, SCE) in 1 m H2SO4 solution under AM 1.5 G irradiation, which is 2.25 times higher than that of the pristine WO3. In addition, the onset potential of NCDs/WO3 photoanode represents a cathodic shift of 70 mV, indicating the charge separation and transfer process are both promoted. These results demonstrate N doped CD modified WO3 can further enhance the conductivity and electrochemical activity surface area, which contributes to the higher photoelectrochemical (PEC) performance. This work provides an efficient strategy for the development of doping carbon material with heteroatoms to increase the charge transfer and charge separation efficiency in PEC water oxidation.
Nylon Fabric Enabled Tough and Flaw Insensitive Stretchable Electronics
Authors: Sim Kyoseung , Gao Yang , Chen Zhou , Song Jizhou , Yu Cunjiang 
Published: December 2018

AbstractThe architecture of stretchable electronics, typically in the fashion of very thin functional electronics on a stretchable rubber substrate, defines their mechanical robustness which is dominantly attributed to the stretchable rubber substrate. Most of the existing and reported stretchable electronics are vulnerable to flaws or cracks in the substrate and subject to fracture upon mechanical deformation, which limits their practical usages. Here, a class of tough and flaw insensitive stretchable electronics enabled by a Nylon/rubber composite substrate is reported. The woven and stretchable fibers in the Nylon fabric are responsible for its high toughness and flaw insensitivity, as they prevent crack propagation by dissipating the energy into the nearby fiber network and also the rubber matrix to yield enhanced toughness and flaw insensitivity. Stretchable electrodes, supercapacitors, and photodetectors with high toughness and flaw insensitivity are developed as examples to illustrate the validity of such a type of stretchable electronics. Systematic studies of the associated materials, fabrication, mechanical and electrical properties, and reliability illustrate the key aspects of such a type of stretchable tough and flaw insensitive electronics and also suggest routes toward stretchable electronics with other functions.
Platinum–Halloysite Nanoclay Nanojets as Sensitive and Selective Mobile Nanosensors for Mercury Detection
Authors: Maric Tijana , Mayorga‐Martinez Carmen C. , Nasir Muhammad Zafir Mohamad , Pumera Martin 
Published: December 2018

AbstractNaturally available tubular Halloysite nanoclay is modified with platinum for the fabrication of autonomous self‐moving nanojets. The nanojets exhibit great performance in the removal of heavy metal ions in aqueous solutions. The heavy metal ions get readily adsorbed onto the large surface area available on the Halloysite nanoclay. The fabricated nanojets are observed to have a greater efficiency with sensing of larger sized metal ions (Hg2+ and Pb2+) as compared to smaller sized ions (Zn2+ and Cd2+), and especially sensitive toward the “detection” of mercury ions. The proposed system displays a wide detection range (0.25–1000 ppb). Moreover, the system displays high sensitivity with low limit of detection (3.24 ppb) achieved, which falls in the permissible range for mercury in drinking water (2–5.5 ppb) as set by the World Health Organisation. The self‐moving nanojets serve as mobile nanosensors for the simultaneous detection and removal of heavy metals in aqueous samples.
Ultrathin Yttria‐Stabilized Zirconia as a Flexible and Stable Substrate for Infrared Nano‐Optics
Authors: Gopalan Kavitha K. , Rodrigo Daniel , Paulillo Bruno , Soni Kamal K. , Pruneri Valerio 
Published: December 2018

AbstractInfrared (IR) technologies have become increasingly relevant as they offer a wide range of applications, from thermal imaging to chemical and biological vibrational spectroscopy. Substrate materials, such as calcium fluoride and zinc selenide, are commonly used for IR optics. Unfortunately, they are typically fragile or hygroscopic, thus potentially producing problems during device fabrication and in the long‐term functional operation. Here, yttria‐stabilized zirconia (YSZ) ceramic is introduced as a flexible and stable platform for IR nano‐optics. In particular, the YSZ substrate is combined with metallic nanostructures and graphene to demonstrate new plasmonic, polarizing, and transparent heating devices, which, at the same time, enable high‐temperature processing and withstand harsh environments thanks to the high YSZ thermal and chemical stability. In addition, it is shown that the YSZ substrate is mechanically flexible, ideally suited for making foldable or bendable devices, and for low‐cost large‐scale roll‐to‐roll fabrication processes. The combination of all the aforesaid features, which are not available from other alternative materials, and this work offers compelling evidence that ultrathin YSZ is a unique substrate for IR applications.
Electrical Control of Electromagnetically Induced Transparency by Terahertz Metamaterial Funneling
Authors: Jung Hyunseung , Jo Hyunwoo , Lee Wonwoo , Kim Beom , Choi Hyunyong , Kang Moon Sung , Lee Hojin 
Published: December 2018

AbstractElectromagnetically induced transparency (EIT) analogs using metamaterials have diverse applications, including nonlinear optics, telecommunications, and biochemical sensors. These EIT analogs can be actively controlled by embedding semiconducting materials into metamaterial structures, but most active EIT metamaterials require complex optical setups and complicated fabrication processes. Graphene‐based EIT metamaterials are some of the most promising active EIT systems because of their simple controllability by electrical bias, but related researches have so far been limited to theoretical or numerical studies. Here, experimentally verified graphene EIT metamaterials are provided by controlling the terahertz funneling of the unique metaatom structures. The proposed active EIT metamaterials are fabricated on flexible and ultrathin polyimide films to acquire the lowest substrate insertion losses and achieve a 1 ps group delay change at the transmission peak of the EIT analog. Moreover, because the proposed metamaterials exhibit resonance properties that vary depending on the polarization direction, the phase delay can be controlled up to 80° from the proposed metamaterials by rotating the incident polarization to the orthogonal direction. Overall, by controlling the group and phase delay of incident waves in a single metamaterial device simultaneously, a multifunctional active tuning system can be realized in the terahertz range.
A Narrowband Photo‐Thermoelectric Detector Using Photonic Crystal
Authors: Monshat Hosein , Liu Longju , Lu Meng 
Published: December 2018

AbstractHere, a wavelength‐specific photo‐thermoelectric (PTE) device is reported that achieves narrowband optical absorption and thermoelectric conversion functions using a stack of thin films on a grating‐patterned substrate. Conventional PTE devices are broadband with the absorption of electromagnetic radiation from ultraviolet to terahertz. There are demands for PTE devices that can exhibit narrowband response at a desired wavelength. Here, the narrowband PTE device consists of a photonic crystal (PC) filter with metal cladding and a thin‐film thermocouple. The PC‐PTE design is investigated numerically to illustrate the underlying energy conversion mechanism. The device is fabricated using nanoreplica molding followed by coating of thin films. The fabricated metal‐cladding PC resonator exhibits a narrowband optical absorption with a resonant absorption coefficient of 85.4% and full‐width‐half‐maximum of 14.8 nm in the visible wavelength range. The PTE measurements show that the thermoelectric output is sensitive to the coupling of incident light and guided‐mode resonance modes. Illuminated under the resonant condition, the PTE device exhibits a responsivity and noise equivalent power of 0.26 V W−1 and 7.5 nW Hz−1/2, respectively. This PC‐PTE technology has the unique attributes of narrowband detection, large surface area, and low cost for the potential application in sensors, optical spectroscopy, and imaging.
Layer‐Dependent Dielectric Function of Wafer‐Scale 2D MoS2
Authors: Song Baokun , Gu Honggang , Fang Mingsheng , Chen Xiuguo , Jiang Hao , Wang Renyan , Zhai Tianyou , Ho Yen‐Teng , Liu Shiyuan 
Published: December 2018

AbstractWafer‐scale, high‐quality, and layer‐controlled 2D MoS2 films on c‐sapphire are synthesized by an innovative two‐step method. The dielectric functions of MoS2 ranging from the monolayer to the bulk are investigated by spectroscopic ellipsometry over an ultra‐broadband (0.73–6.42 eV). Up to five critical points (CPs) in the dielectric function spectra are precisely distinguished by CP analysis, and their physical origins are identified in the band structures with the help of first‐principles calculations. Results demonstrate that the center energies of these CPs exhibit intriguing layer dependency, which are interpreted by the intrinsic layer‐dependent transitions in MoS2. Specially, the change in the imaginary part of the dielectric functions versus the thickness exhibits a “W” like curve, and the two valley bottoms appear at about four‐layer and 10‐layer respectively. These complex fluctuations are attributed to the alternating domination of the decreasing excitonic effect, the increasing joint density of states, and the mass density increase in relative thick MoS2 samples.