bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of RF performances of advanced MOS transistors from DC and low frequency measurements
Authors: Maafri Djabar , Kazemi Esfeh Babak , Saadi Abdelhalim , Yagoub Mustapha C. E. , Raskin Jean‐Pierre 
Published: August 2018

AbstractThis work presents a new method to easily and rapidly extract RF figures of merit of MOSFET transistors. Using DC and low frequency measurements, the extrinsic resistances (Rg, Rs, Rd), the intrinsic conductances (gm, gd), and the input capacitance Cgg have been extracted. The evaluation of these parameters has enabled to compute 2 RF figures of merit (FoM), namely, the current gain cutoff frequency fT and the maximum oscillation frequency fmax. It has been shown that both the proposed method and the conventional RF extraction technique give quite close values.
Study of field distortions introduced by antenna array mobile carrier body
Authors: Ashikhmin A. V. , Pasternak Yu. G. , Rembovsky Yu. A. , Fedorov S. M. 
Published: August 2018

AbstractIn this article was presented a method for optimal location of the “virtual” antenna array elements, based on obtaining a surface map of the same field phase distortion, averaged over the set of frequencies and azimuthal coordinates. This method does not require information about geometry and material properties of the antenna array carrier body, and can significantly improve accuracy of mobile radio direction‐finding systems.
Yagi‐Uda nantenna for 1550 nanometers optical communication systems
Authors: Sethi Waleed Tariq , de Sagazan Olivier , Vettikalladi Hamsakutty , Fathallah Habib , Himdi Mohamed 
Published: August 2018

AbstractIn this letter we propose, for the very first time, a Molybdenum based Yagi‐Uda high‐directional nantenna. It is realized using simple Low Pressure Chemical Vapor Deposition (LPCVD) technique on a silicon substrate for 1550 nm standard optical communication system. The proposed nantenna uses Molybdenum metal as a ground plane while the Yagi‐Uda driven, radiator and directing elements are made up of Aluminum. Grounded Co‐Planar Waveguide (GCPW) technique is used for exciting the nanoantenna in CST Microwave Studio simulator. The nantenna achieves an impedance bandwidth of (193.37–193.71 THz) at a center frequency of 193.5 THz with a high gain and directivity of 12.9 and 16.6 dB, respectively. Near‐field and far‐field performance of the proposed nantenna is also demonstrated via extensive numerical simulations. The results achieved makes the proposed nantenna a viable candidate for applications in the field of nanophotonic circuits and photovoltaic devices working in the optical C‐band window.
Narrowband shielding against electromagnetic interference in LTE 4G systems using complementary frequency selective surfaces
Authors: da Silva B. S. , Campos A. L. P. S. , Gomes Neto A. 
Published: August 2018

AbstractThis article presents the project and fabrication of an electromagnetic shielding using complementary frequency selective surfaces. The proposed structure acts as low pass filter in the bands 1.8–2.3 GHz and 2.86–3.47 GHz, with a narrowband null rejecting undesired frequencies, in this case, 4G band (2.50–2.69 GHz). The project begins by analyzing geometries very well known in the specific literature (cross‐dipole and square‐loop), separately, to determine the dimensions of these geometries efficiently. In addition, computational simulations of a new geometry are made, joining the initial geometries, to observe the behavior of the interaction between them. Therefore, the CFSS is proposed and studied to achieve the desired frequency response. By using the screen printing technique, the EMI shielding is fabricated. Finally, its frequency response is validated experimentally. A good agreement between measurement and simulation is demonstrated in this article, as well as the angular stability of the proposed structure.
Triband planar shared‐aperture antenna array with similar‐shaped radiation patterns
Authors: Li Mingxing , Wu Yongle , Qu Meijun , Jiao Lingxiao , Liu Yuanan 
Published: August 2018

AbstractIn this paper, a triband planar shared‐aperture antenna array is proposed. The proposed antenna array could obtain similar‐shaped radiation patterns at three operating frequency bands. The total structure includes two radiation patch layers, a ground layer and a feeding network layer. Metal vias are used to excite the stacked patches, leading to three resonant frequencies. To verify the proposed antenna array, a 4 × 4 prototype with the overall size of 6.4 × 5.3 × 0.7 cm3 is fabricated and measured. The measured |S11| < −10 dB bandwidths are 13.34–13.82, 17.95‐18.61, and 23.8–25.15 GHz, and measured realized gains are 10.8, 11, and 14.4 dB at 13.5, 18, and 24 GHz.
Low‐cost quad‐band dual antipodal Vivaldi antenna using microstrip to CPS transition
Authors: Bulgaroni Renan , Torres Wesley M. , de Araujo Humberto X. , Casella Ivan R. S. , Capovilla Carlos E. 
Published: August 2018

AbstractIn this article, a new topology of antenna for multi‐band application is proposed, designed, and characterized. This one is based on an array of two antipodal Vivaldi antennas diametrically placed and fed through a microstrip to coplanar strip (CPS) transition, which generates an odd‐order coupling at the input of the elements. The designed antenna was built on a low‐cost substrate (FR‐4), with compatible operation at 1.85–2.00, 2.20–2.85, 3.35–3.81, and 5.00–6.9 GHz (PCS, Bluetooth, WLAN, WiMAX, TD‐SCDMA, and ISM). The measurements, on a fabricated prototype, and the simulations demonstrate the operability and functionality, with satisfactory performance, of the proposed antenna topology.
Abdominal DCE‐MRI reconstruction with deformable motion correction for liver perfusion quantification
Authors: Johansson Adam , Balter James M. , Cao Yue 
Published: August 2018

Purpose
Abdominal dynamic contrast‐enhanced (DCE) MRI suffers from motion‐induced artifacts that can blur images and distort contrast‐agent uptake curves. For liver perfusion analysis, image reconstruction with rigid‐body motion correction (RMC) can restore distorted portal‐venous input functions (PVIF) to higher peak amplitudes. However, RMC cannot correct for liver deformation during breathing. We present a reconstruction algorithm with deformable motion correction (DMC) that enables correction of breathing‐induced deformation in the whole abdomen.MethodsRaw data from a golden‐angle stack‐of‐stars gradient‐echo sequence were collected for 54 DCE‐MRI examinations of 31 patients. For each examination, a respiratory motion signal was extracted from the data and used to reconstruct 21 breathing states from inhale to exhale. The states were aligned with deformable image registration to the end‐exhale state. Resulting deformation fields were used to correct back‐projection images before reconstruction with view sharing. Images with DMC were compared to uncorrected images and images with RMC.ResultsDMC significantly increased the PVIF peak amplitude compared to uncorrected images (P << 0.01, mean increase: 8%) but not compared to RMC. The increased PVIF peak amplitude significantly decreased estimated portal‐venous perfusion in the liver (P << 0.01, mean decrease: 8 ml/(100 ml·min)). DMC also removed artifacts in perfusion maps at the liver edge and reduced blurring of liver tumors for some patients.ConclusionsDCE‐MRI reconstruction with DMC can restore motion‐distorted uptake curves in the abdomen and remove motion artifacts from reconstructed images and parameter maps but does not significantly improve perfusion quantification in the liver compared to RMC.
Internal radiation dose estimation using multiple D‐shuttle dosimeters for positron emission tomography (PET): A validation study usingNEMAbody phantom
Authors: Islam Md. Shahidul , Watanuki Shoichi , Tashiro Manabu , Watabe Hiroshi 
Published: August 2018

PurposeInternal radiation dosimetry plays an important role in ensuring the safe use of positron emission tomography (PET) technology and is a legal requirement in most countries. We propose a new technique to estimate the internal radiation dose inPETstudies by means of multiple D‐shuttle dosimeters attached on the body surface of the patient.MethodsRadioactivity in a source organ was estimated iteratively using measurements from multiple D‐shuttle dosimeters with a maximum‐likelihood expectation‐maximization (MLEM) algorithm with dose response from a source to a D‐shuttle dosimeter computed by Monte Carlo simulation. To validate our technique, we performed a phantom study using a National Electrical Manufacturers Association (NEMA) body phantom. The fillable compartments (torso cavity and six spheres) of the phantom were filled with18F‐FDGmixed with pure water using an 800:1 sphere‐to‐background radioactivity concentration ratio. The radioactivity concentrations present in the torso cavity and six spheres were 0.00165MBq/mLand 1.32MBq/mL, respectively. The initial radioactivities of the torso cavity and six spheres (treated as source organs) were 15.9MBq (torso cavity), 34.7MBq (37 mm sphere), 15.1MBq (28 mm sphere), 7.27MBq (22 mm sphere), 3.26MBq (17 mm sphere), 1.54MBq (13 mm sphere), and 0.697MBq (10 mm sphere). Eleven D‐shuttle dosimeters were attached to theNEMAbody phantom surface to obtain information on body surface dose and a mathematicalNEMAbody phantom has been modeled in the Heavy Ion Transport Code System (PHITS) Monte Carlo simulation code.ResultsRadioactivity was estimated in 2 min intervals over a 110‐min total dose time using our proposed technique. A significant correlation (R2= 0.992) was found between actual radioactivity and estimated radioactivity at every 2 min interval for each source organ. The estimated initial radioactivity (mean with standard deviation) was 16.5 ± 0.311MBq (torso cavity), 33.0 ± 0.624MBq (37 mm sphere), 15.7 ± 0.189MBq (28 mm sphere), 7.11 ± 0.738MBq (22 mm sphere), 4.17 ± 0.083MBq (17 mm sphere), 1.48 ± 0.469MBq (13 mm sphere), and 0.865 ± 0.313MBq (10 mm sphere), which were very close to the actual initial radioactivity measurements for each source organ.ConclusionsThe phantom study showed that our technique worked successfully. This technique could be used to estimate internal radiation dosimetry in a clinicalPETstudy.
Comprehensive behavioral analysis of indoleamine 2,3‐dioxygenase knockout mice
Authors: Hirata Nao , Hattori Satoko , Shoji Hirotaka , Funakoshi Hiroshi , Miyakawa Tsuyoshi 
Published: August 2018

AbstractAimIndoleamine 2,3‐dioxygenase 1 (IDO1) metabolizes the essential amino acid tryptophan into kynurenine derivatives, which are involved in neural activity via the kynurenine pathway (KP). IDO1 is an initial rate‐limiting enzyme in the KP and is activated by stress and/or inflammation. The perturbation of IDO1 activity, which causes KP imbalance, is associated with psychiatric and neurological disorders. It has been reported that wild‐type (WT) mice under inflammatory conditions show increased anxiety‐like behavior and decreased novel object recognition, whereas Ido1 knockout (KO) mice do not display these behaviors. However, the behavioral phenotypes of Ido1 KO mice have not yet been fully examined under non‐inflammatory conditions.MethodsWe subjected Ido1 KO mice to a comprehensive behavioral test battery under normal conditions.ResultsIdo1 KO mice and WT mice showed similar locomotor activity, anxiety‐like behavior, social behavior, depression‐like behavior, and fear memory. In the T‐maze test, Ido1 KO mice exhibited weak but nominally significant impairment in the working memory task of the T‐maze, but this result failed to reach study‐wide significance.ConclusionsIdo1 KO mice did not show any clear behavioral abnormalities under normal conditions. Further studies may be necessary to investigate their behavioral phenotype under inflammatory conditions due to their known roles in inflammation.
Novel conjugated patterns of PBDT‐DTNT and PBDT‐TIPS‐DTNT‐DT complicated polymers onto graphenic nanosheets
Authors: Aghapour Sahar , Agbolaghi Samira , Charoughchi Somaiyeh , Sarvari Raana , Abbasi Farhang 
Published: August 2018

AbstractThe delicacy and connectivity of conductive patterns developed via poly[benzodithiophene‐bis(decyltetradecylthien)naphthothiadiazole] (PBDT‐DTNT) and poly[bis(triisopropylsilylethynyl)benzodithiophene‐bis(decyltetradecylthien)naphthobisthiadiazole] (PBDT‐TIPS‐DTNT‐DT) polymers were investigated on reduced graphene oxide (rGO) nanosheets. The principal driving force for assembly of PBDT‐DTNT and PBDT‐TIPS‐DTNT‐DT chains onto the rGO nanosheets was π‐stacking. In contrast to poly(3‐hexylthiophene) (P3HT), the surface modification of rGO limited the self‐assembly of PBDT‐DTNT and PBDT‐TIPS‐DTNT‐DT complicated polymers. The structure of PBDT‐DTNT and PBDT‐TIPS‐DTNT‐DT chains having fused and infused thiophenic and benzenic rings hindered their molecular ordering compared to P3HT, and therefore the selected area electron diffraction plots demonstrated rings instead of isolated growth planes. Although 2‐thiophene acetic acid (TAA) functional groups and poly(3‐dodecylthiophene) (PDDT) grafted onto rGO nanosheets did not alter the stacking type of the complicated polymers, it made their attachment more difficult. The thickness of π‐stacked patterns ranged from 55 to 70 nm. In the modified areas of rGO, the PBDT‐DTNT and PBDT‐TIPS‐DTNT‐DT chains were not capable of being deposited with a π‐interaction. Hence, the surface modification agents prevented the complicated polymers from interconnectedly assembling and, consequently, constructing longer and larger patterns. This hindrance was more noticeable for the supramolecules based on grafted rGO (rGO‐g‐PDDT) and PBDT‐TIPS‐DTNT‐DT. The conductivity of PBDT‐DTNT/rGO superstructures was the highest (14.61–14.89 S cm−1). The patterned nanohybrids could be considered as potential super‐materials for morphology‐templating in the active layers of organic–inorganic photovoltaics. © 2018 Society of Chemical Industry
Bile salt hydrolases: Structure and function, substrate preference, and inhibitor development
Authors: Dong Zixing , Lee Byong H. 
Published: August 2018

AbstractThe worldwide trend of limiting the use of antibiotic growth promoters (AGPs) in animal production creates challenges for the animal feed industry, thus necessitating the development of effective non‐antibiotic alternatives to improve animal performance. Increasing evidence has shown that the growth‐promoting effect of AGPs is highly correlated with the reduced activity of bile salt hydrolase (BSH, EC 3.5.1.24), an intestinal bacteria‐producing enzyme that has a negative impact on host fat digestion and energy harvest. Therefore, BSH inhibitors may become novel, attractive alternatives to AGPs. Detailed knowledge of BSH substrate preferences and the wealth of structural data on BSHs provide a solid foundation for rationally tailored BSH inhibitor design. This review focuses on the relationship between structure and function of BSHs based on the crystal structure, kinetic data, molecular docking and comparative structural analyses. The molecular basis for BSH substrate recognition is also discussed. Finally, recent advances and future prospectives in the development of potent, safe, and cost‐effective BSH inhibitors are described.
Using 1HN amide temperature coefficients to define intrinsically disordered regions: An alternative NMR method
Authors: Okazaki Hiroki , Matsuo Naoki , Tenno Takeshi , Goda Natsuko , Shigemitsu Yoshiki , Ota Motonori , Hiroaki Hidekazu 
Published: August 2018

AbstractThis report describes a cost‐effective experimental method for determining an intrinsically disordered protein (IDP) region in a given protein sample. In this area, the most popular (and conventional) means is using the amide (1HN) NMR signal chemical shift distributed in the range of 7.5–8.5 ppm. For this study, we applied an additional step: analysis of 1HN chemical shift temperature coefficients (1HN‐CSTCs) of the signals. We measured 1H–15N two‐dimensional NMR spectra of model IDP samples and ordered samples at four temperatures (288, 293, 298, and 303 K). We derived the 1HN‐CSTC threshold deviation, which gives the best correlation of ordered and disordered regions among the proteins examined (below −3.6 ppb/K). By combining these criteria with the newly optimized chemical shift range (7.8–8.5 ppm), the ratios of both true positive and true negative were improved by approximately 19% (62–81%) compared with the conventional “chemical shift‐only” method.
Refining protein structures using enhanced sampling techniques with restraints derived from an ensemble‐based model
Authors: Ma Tianqi , Zang Tianwu , Wang Qinghua , Ma Jianpeng 
Published: August 2018

AbstractThis paper reports a method for high‐accuracy protein structural refinement, which is a direct extension of the method in our recent publication (Zang, J Chem Phys 2018; 149:072319). It combines a parallel continuous simulated tempering (PCST) method with a temperature‐dependent restraint and a blind model selection scheme. In this work, a single‐reference‐based restraint in previous work was changed to an ensemble‐based model (EBM), in which the non‐bonded Lennard–Jones term for each contacting atomic pair in previous restraining potential was replaced by a multi‐Gaussian function whose parameters are derived from an ensemble of structures such as the ones from various CASP participating groups. The purpose of EBM is to take advantage of partial “correctness” distributed among members of the structural ensemble. Totally 18 targets were refined from the refinement category of CASP10, CASP11 and CASP12. In Top‐1 group, 11 out of 18 targets had better models (greater GDT_TS scores) than the CASPR participants. In Top‐5 group, nine out of 18 were better. Our results show that PCST‐EBM method can considerably improve the low‐accuracy structures.
The first crystal structure of crustacean ferritin that is a hybrid type of H and L ferritin
Authors: Masuda Taro , Zang Jiachen , Zhao Guanghua , Mikami Bunzo 
Published: August 2018

AbstractFerritin, a ubiquitous iron storage protein, has a crucial role in innate immunity in arthropods, which have no adaptive immune system. Arthropods are thought to have two types of ferritin molecules: the secreted type and the cytosolic type. Here, we present the first crystal structure of ferritin from crustacean, kuruma prawn (Marsupenaeus japonicus), at 1.16 Å resolution. This shrimp ferritin (MjFer) is the cytosolic type, and its structure shows well‐conserved ferritin fold composed of a 4‐helix bundle that assembles into a cage‐like 24‐mer. The structure of MjFer was more similar to those of human and vertebrate ferritins than to that of the secreted‐type arthropod ferritin from an insect. MjFer possesses both a ferroxidase site and a nucleation site, which are the main characteristics of vertebrate H and L chain ferritins, respectively. The first crystal structure of crustacean ferritin, MjFer, has exceptionally high quality that provides the detailed structural information of metal moving pathway in ferritin.
Prediction of protein flexibility using a conformationally restrained contact map
Authors: Vera Rebecca , Synsmir‐Zizzamia Melissa , Ojinnaka Sarah , Snyder David A. 
Published: August 2018

AbstractKnowledge of protein flexibility is crucial to understanding protein function. However, probing protein flexibility by either experiment or computational simulations is a difficult process. In particular, many computational approaches to understanding protein flexibility require an experimentally determined protein structure. The Conformationally Restrained Contact Map (CoRe‐CMap) approach reported here couples protein disorder predictions with protein structure predictions and only requires sequence data to predict protein flexibility. This paper reports the application of the CoRe‐CMap model to predicting Lipari‐Szabo order parameters of all proteins for which experimentally derived Lipari‐Szabo order parameters are available in the BioMagResBank: the median root mean square deviation between a protein's predicted and experimentally derived order parameters is 0.124. Additionally, application of the CoRe‐CMap model to predict Lipari‐Szabo order parameters for the 10th Type III Domain in Fibronectin and a homologous domain from Tenascin demonstrates the ability of CoRe‐CMap to predict functionally important differences in protein flexibility.
New global potential energy surface of the MgH2 system and dynamics studies of the reaction H + MgH → Mg + H2
Authors: Zhang Yong , Wang Jiemin , Li Wentao 
Published: August 2018

AbstractA new global potential energy surface for the ground state of MgH2 was constructed using the permutation invariant polynomial neural network method. About 70 000 ab initio energy points were calculated via the multi‐reference configuration interaction method method with aug‐cc‐pVTZ and aug‐cc‐pVQZ basis sets, and these points were used to construct the potential energy surface (PES). To avoid basis set superposition error, the basis set was extrapolated to the complete basis set limit using the two point energy extrapolation formula. The root mean square error of the present PES is only 8.85 meV. Initial state (v = 0, j = 0) dynamics studies were performed using the time‐dependent wave packet method with a second‐order split operator for the total angular momentum J up to a value of 50. Furthermore, the reaction probability, integral cross section, and thermal rate constant are reported and compared with available theoretical studies.
Challenges in predicting ΔrxnG in solution: Hydronium, hydroxide, and water autoionization
Authors: Dhillon Shamneet , East Allan L. L. 
Published: August 2018

AbstractStandard non‐semiempirical continuum‐dielectric orbital‐based methods horribly overpredict, by 26‐50 kcal mol−1, the Gibbs energy for the water autoionization reaction 2 H2O(l) → H3O+(aq) + OH–(aq). Here, we demonstrate these errors, fully investigate the reasons for these errors, and show that the use of 4 explicit solvent within the continuum (the “semicontinuum,” “cluster‐continuum,” or “hybrid” technique) can reduce the error of a standard continuum model from 50 to 2 kcal mol−1. Results from pure cluster, pure continuum (several versions including semiempirical ones), and semicontinuum modeling are each presented and discussed. We recommend use of 3 waters around hydronium and 4 waters around hydroxide with standard continua whenever these ions are involved in reaction. To the possible surprise of some, time‐consuming molecular‐dynamics simulations are not needed to reproduce this problematic energy.
Quantum confinement effects on the harmful‐gas‐sensing properties of silicon nanowires
Authors: de Santiago Francisco , Miranda Álvaro , Trejo Alejandro , Salazar Fernando , Carvajal Eliel , Cruz‐Irisson Miguel , Pérez Luis A. 
Published: August 2018

AbstractIn this work, the effects of the adsorption of different toxic gas molecules CO, NO, NO2, and SO2 on the electronic structure of hydrogen‐passivated, [111]‐oriented, silicon nanowires (H‐SiNWs), are studied through density functional theory. To analyze the effects of quantum confinement, three nanowire diameters are considered. The results show that the adsorption energies are almost independent of the nanowire diameter with NO2 being the most strongly adsorbed molecule (∼3.44 eV). The electronic structure of small‐diameter H‐SiNWs is modified due to the creation of isolated defect‐like states on molecule adsorption. However, these discrete levels are eventually hybridized with the former nanowire states as the nanowire diameter increases and quantum confinement effects become less evident. Hence, there is a range of small nanowire diameters with distinctive band gaps and adsorption energies for each molecule species.