bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional characterization of a loss-of-function mutant I324M of arginine vasopressin receptor 2 in X-linked nephrogenic diabetes insipidus
Authors: Wang Lixia , Guo Weihong , Fang Chunyun , Feng Wenli , Huang Yumeng , Zhang Xiaona , Liu Ming , Cui Jingqiu 
Published: May 2021

AbstractX-linked nephrogenic diabetes insipidus (X-linked NDI) is a rare inherited disease mainly caused by lost-of-function mutations in human AVPR2 gene encoding arginine vasopressin receptor 2 (V2R). Our focus of the current study is on exploration of the functional and biochemical properties of Ile324Met (I324M) mutation identified in a pedigree showing as typical recessive X-linked NDI. We demonstrated that I324M mutation interfered with the conformation of complex glycosylation of V2R. Moreover, almost all of the I324M-V2R failed to express on the cell surface due to being captured by the endoplasmic reticulum control system. We further examined the signaling activity of DDAVP-medicated cAMP and ERK1/2 pathways and the results revealed that the mutant receptor lost the ability in response to DDAVP stimulation contributed to the failure of accumulation of cAMP and phosphorylated ERK1/2. Based on the characteristics of molecular defects of I324M mutant, we selected two reagents (SR49059 and alvespimycin) to determine whether the functions of I324M-V2R can be restored and we found that both compounds can significantly “rescue” I324M mutation. Our findings may provide further insights for understanding the pathogenic mechanism of AVPR2 gene mutations and may offer some implications on development of promising treatments for patients with X-linked NDI.
Comparison of short-term surgical outcomes using da Vinci S, Si and Xi Surgical System for robotic gastric cancer surgery
Authors: Ojima Toshiyasu , Nakamura Masaki , Hayata Keiji , Kitadani Junya , Takeuchi Akihiro , Yamaue Hiroki 
Published: May 2021

AbstractWhen compared with the second/third generation da Vinci S/Si, the fourth generation Xi surgical system may allow for greater efficiency and result in shorter operation times during robotic gastrectomy (RG) for gastric cancer (GC). We directly compare surgical outcomes between the conventional S/Si and the newer Xi robotic platform for the treatment of GC. This is a single-center retrospective study of 148 consecutive patients with GC who underwent RG. Of these patients, 20 patients were treated with the S, 30 patients with the Si, and 98 patients with the Xi. The overall operation time was significantly longer in the S group (386.5 min) than in the other groups (Si group: 292 min; Xi group: 297 min) (S vs. Si: P = 0.010; S vs. Xi: P = 0.001). We observed no difference, however, between the newer Xi and Si systems in operation time. Intraoperative blood loss was similar across the three groups. The overall postoperative complication rate in the Xi group (8.2%) was lower than that of the S group (10%) and the Si group (13.3%), but the difference was not significant. The newer Xi system did not provide significant intraoperative or early postoperative advantages over the Si system.
A human respiratory tract-associated bacterium with an extremely small genome
Authors: Fukuda Kazumasa , Yamasaki Kei , Ogura Yoshitoshi , Kawanami Toshinori , Ikegami Hiroaki , Noguchi Shingo , Akata Kentarou , Katsura Keisuke , Yatera Kazuhiro , Mukae Hiroshi , Hayashi Tetsuya , Taniguchi Hatsumi 
Published: May 2021

AbstractRecent advances in culture-independent microbiological analyses have greatly expanded our understanding of the diversity of unculturable microbes. However, human pathogenic bacteria differing significantly from known taxa have rarely been discovered. Here, we present the complete genome sequence of an uncultured bacterium detected in human respiratory tract named IOLA, which was determined by developing a protocol to selectively amplify extremely AT-rich genomes. The IOLA genome is 303,838 bp in size with a 20.7% GC content, making it the smallest and most AT-rich genome among known human-associated bacterial genomes to our best knowledge and comparable to those of insect endosymbionts. While IOLA belongs to order Rickettsiales (mostly intracellular parasites), the gene content suggests an epicellular parasitic lifestyle. Surveillance of clinical samples provides evidence that IOLA can be predominantly detected in patients with respiratory bacterial infections and can persist for at least 15 months in the respiratory tract, suggesting that IOLA is a human respiratory tract-associated bacterium.
Unconventional satellite resistance peaks in moiré superlattice of h-BN/ AB-stacked tetralayer-graphene heterostructures
Authors: Mukai Fumiya , Horii Kota , Ebisuoka Ryoya , Watanabe Kenji , Taniguchi Takashi , Yagi Ryuta 
Published: May 2021

AbstractMost studies on moiré superlattices formed from a stack of h-BN (two-dimensional hexagonal boron nitride) and graphene have focused on single layer graphene; graphene with multiple layers is less understood. Here, we show that a moiré superlattice of multilayer graphene shows features arising from the anisotropic Fermi surface affected by the superlattice structure. The moiré superlattice of a h-BN/AB-stacked tetralayer graphene heterostructures exhibited resistivity peaks showing a complicated dependence on the perpendicular electric field. The peaks were not due to secondary Dirac cones forming, but rather opening of the energy gap due to folding of the anisotropic Fermi surface. In addition, superlattice peaks resulted from mixing of light- and heavy-mass bilayer-like bands via the superlattice potential. The gaps did not open on the boundary of the superlattice Brillouin zone, but rather opened inside it, which reflected the anisotropy of the Fermi surface of multilayer graphene.
Out-of-plane trion emission in monolayer WSe2 revealed by whispering gallery modes of dielectric microresonators
Authors: Andres-Penares Daniel , Habil Mojtaba Karimi , Molina-Sánchez Alejandro , Zapata-Rodríguez Carlos J. , Martínez-Pastor Juan P. , Sánchez-Royo Juan F. 
Published: May 2021

AbstractThe manipulation of light emitted by two-dimensional semiconductors grounds forthcoming technologies in the field of on-chip communications. However, these technologies require from the so elusive out-of-plane photon sources to achieve an efficient coupling of radiated light into planar devices. Here we propose a versatile spectroscopic method that enables the identification of the out-of-plane component of dipoles. The method is based on the selective coupling of light emitted by in-plane and out-of-plane dipoles to the whispering gallery modes of spherical dielectric microresonators, in close contact to them. We have applied this method to demonstrate the existence of dipoles with an out-of-plane orientation in monolayer WSe2 at room temperature. Micro-photoluminescent measurements, numerical simulations based on finite element methods, and ab-initio calculations have identified trions as the source responsible for this out-of-plane emission, opening new routes for realizing on-chip integrated systems with applications in information processing and quantum communications.
Effects of UHMWPE viscoelasticity on the squeeze‐film lubrication of hip replacements
Authors: Lu Xianjiu , Meng Qingen , Jin Zhongmin 
Published: May 2021

AbstractMany studies have been performed to analyse the lubrication of artificial joints since the pioneer work by the late Professor Duncan Dowson. However, the viscoelastic deformation of one of the most widely used bearing materials, ultra‐high‐molecular‐weight polyethylene (UHMWPE), has only been considered recently. The described study attempted to investigate the effect of UHMWPE viscoelasticity on the elastohydrodynamic lubrication of such a soft artificial hip replacement under squeeze‐film motion. A transient viscoelastic squeeze‐film lubrication model of a typical hip implant was developed and solved to obtain the film thickness and pressure distributions. A boundary film thickness was adopted to consider the direct and indirect lubricant contact conditions. The results showed that the viscoelasticity had marked effects on the squeeze‐film lubrication performance of UHMWPE artificial hip joints. The minimum film thickness in the viscoelastic model was smaller than that of the elastic model, causing an earlier direct contact. However, the film thickness within the central contact region in the viscoelastic model was greater than that of the elastic model due to the restricted flow of the lubricant, therefore enhancing the lubricating effect and particularly with a short relaxation time and mechanical loss factor.
Robust iterative learning control for uncertain continuous‐time system with input delay and random iteration‐varying uncertainties
Authors: Shokri‐Ghaleh Hamid , Ganjefar Soheil , Shahri Alireza Mohammad 
Published: May 2021

AbstractThis study deals with the problem of robust iterative learning control (ILC) for linear continuous‐time systems with input delay subject to uncertainties in input delay, plant dynamic, reference trajectory, initial conditions and disturbances. Using the internal model control (IMC) structure in the frequency domain, an ILC scheme is proposed in which the IMC structure is responsible for coping with uncertainties in both delay time and plant dynamic. Sufficient conditions are derived to ensure that the tracking error expectation is bounded and converges monotonically to a small neighbourhood of zero (in the ‐norm sense) when uncertainties in reference trajectory, initial conditions and disturbances vary randomly from trial to trial. It is shown that the derived conditions are still valid to guarantee both boundedness and monotonic convergence of the tracking error variance (in the ‐norm sense). Illustrative examples are provided to demonstrate the effectiveness of the proposed method.
A low phase noise microwave source for high‐performance CPT Rb atomic clock
Authors: Li Xiaodong , Yun Peter , Li Qinglin , Ju Bowen , Yu Shaoshao , Hao Qiang , Du Runchang , Xu Feng , Li Wenbing , Gao Yuping , Zhang Shougang 
Published: May 2021

AbstractPhase noise of the frequency synthesizer is one of the main limitations to the short‐term stability of microwave atomic clocks. Here, a low‐noise, simple‐architecture microwave frequency synthesizer for a coherent population trapping (CPT) clock is demonstrated. The synthesizer is mainly composed of a 100 MHz oven‐controlled crystal oscillator (OCXO), a microwave comb generator, and a direct digital synthesizer (DDS). The absolute phase noises of 3.417 GHz signal are measured to be −55 dBc/Hz, −81 dBc/Hz, −111 dBc/Hz and −134 dBc/Hz, respectively, for 1 Hz, 10 Hz, 100 Hz and 1 kHz offset frequencies, which shows only 1 dB deterioration at the second harmonic of the modulation frequency of the atomic clock. The estimated frequency stability of intermodulation effect is 4.7 × 10−14 at 1 s averaging time, which is about half order of magnitude lower than that of the state‐of‐the‐art CPT Rb clock. Our work offers an alternative microwave synthesizer for high‐performance CPT Rb atomic clock.
The importance of coil conductivity and eddy current effects in the analysis of electromagnetic forming process
Authors: Cao Quanliang , Xia Liangyu , Li Xian , Du Limeng , Lai Zhipeng , Han Xiaotao , Li Liang 
Published: May 2021

AbstractCoil design and performance analysis are critical for the electromagnetic forming (EMF) process. However, previous studies have paid little attention to the coil conductivity, and the influence of eddy current effects in coil conductors on the forming process has not been well understood. This work aims to address these problems through numerical and experimental investigations. It is found that, due to the eddy current effects, the uneven current distribution appears in the coil conductors that should be considered when analysing the forming process, especially for the cases with large heights of coil conductors. Meanwhile, an important and interesting discovery is that the eddy current effects can greatly reduce the sensitivity of the coil conductivity with respect to the workpiece deformation, the Joule heating and the temperature rise in the coil. For instance, compared to a forming system with a copper coil, the forming height of the workpiece in the forming system with an AA5083‐O coil is reduced by less than 5 % under the same discharge energy, while the copper conductivity is 3.3 times that of the latter. These results are helpful to understand the EMF process and achieve the optimal design of coils.
Viability of providing spinning reserves by RES in Spanish island power systems
Authors: Rajabdorri Mohammad , Sigrist Lukas , Lobato Enrique , Prats Maria del Carmen , Echavarren Francisco M. 
Published: May 2021

AbstractThis paper assesses the viability of providing down and up spinning reserves by renewable energy resources (RES) in island power systems. The process consists of evaluating the impact of providing spinning reserve on the system operation costs of different islands by simulating the unit commitment problem. The assessment is carried out for La Palma (small size) and Tenerife (medium size) island power systems, and by considering different wind source availability scenarios for sample weeks of different seasons in current and future years. This paper differentiates between up and down reserves and studies their impacts separately. Results show that enabling RES to provide just down spinning reserve has economic benefits for all scenarios, by reducing over 40% the amount of thermal generation and over 30% the systems costs for high wind scenarios. It also confirms that employing variable deloading of wind energy as a source of up reserve is advisable, mainly in scenarios with high share of wind sources. In some scenarios, using RES as reserve provider, reduces the amount of thermal generation more than 50%, compared to when RES does not participate as a source of reserve, and can even lead to a full RES coverage of demand.
Transfer learning‐based radar imaging with deep convolutional neural networks for distributed frequency modulated continuous waveform multiple‐input multiple‐output radars
Authors: Seo Jiho , Yang Yunji , Hong Yong‐gi , Park Jaehyun 
Published: May 2021

AbstractDeep‐learning‐based radar imaging is developed with distributed frequency modulated continuous waveform multiple‐input multiple‐output (FMCW MIMO) radars in which a deep‐learning approach based on the convolutional neural network (CNN) is proposed to achieve radar images robust to adverse circumstances. Differently from the existing deep‐learning methods applied to radar object recognition, the deramped radar signal is exploited as the input of the proposed deep CNN (DCNN) without any processing related to the spectrogram transform and the subspace decomposition. To effectively train the proposed DCNN, the received signal is reformulated in terms of the reflection gain values in the (azimuth, range) patches in the image region of interest such that the output vector of the DCNN is composed of the reflection gain values in the associated patches. Furthermore, to overcome the limitations on the amount of training data and training time, the transfer learning approach is effectively applied to the distributed FMCW MIMO radar imaging. The proposed radar imaging is assessed with synthetic simulation data. Specifically, by transferring the pretrained DCNN model for a given reference radar to other distributed radars, the distributed radars can save about 52.4 % in training time compared with a DCNN having the same architecture but without transfer learning.
Operational Dst index prediction model based on combination of artificial neural network and empirical model
Authors: Park Wooyeon , Lee Jaejin , Kim Kyung-Chan , Lee JongKil , Park Keunchan , Miyashita Yukinaga , Sohn Jongdae , Park Jaeheung , Kwak Young-Sil , Hwang Junga , Frias Alexander , Kim Jiyoung , Yi Yu 
Published: May 2021

In this paper, an operational Dst index prediction model is developed by combining empirical and Artificial Neural Network (ANN) models. ANN algorithms are widely used to predict space weather conditions. While they require a large amount of data for machine learning, large-scale geomagnetic storms have not occurred sufficiently for the last 20 years, Advanced Composition Explorer (ACE) and Deep Space Climate Observatory (DSCOVR) mission operation period. Conversely, the empirical models are based on numerical equations derived from human intuition and are therefore applicable to extrapolate for large storms. In this study, we distinguish between Coronal Mass Ejection (CME) driven and Corotating Interaction Region (CIR) driven storms, estimate the minimum Dst values, and derive an equation for describing the recovery phase. The combined Korea Astronomy and Space Science Institute (KASI) Dst Prediction (KDP) model achieved better performance contrasted to ANN model only. This model could be used practically for space weather operation by extending prediction time to 24 h and updating the model output every hour.
Conceptual design of heavy ion beam probes on the PLATO tokamak
Authors: Ido T. , Fujisawa A. , Takemura K. , Kobayashi T.-K. , Nishimura D. , Kasuya N. , Fukuyama A. , Moon C. , Yamasaki K. , Inagaki S. , Nagashima Y. , Yamada T. 
Published: May 2021

Heavy ion beam probe (HIBP) systems have been designed for the new tokamak, PLATO [A. Fujisawa, AIP Conf. Proc. 1993, 020011 (2018)]. The designs have been completed, and the installations are in progress. Two HIBPs are being installed in toroidal sections 180° apart to investigate long-range correlations in the toroidal direction. Each HIBP consists of an injection beamline and a detection beamline as usual. Yet, one of the HIBPs is equipped with an additional detection beamline; the measurement positions of its two detection beamlines can be placed on almost the same magnetic surface yet at poloidal angles that differ by ∼180°. The use of three detection beamlines allows us to investigate spatial asymmetry and long-range correlations in both the toroidal and poloidal directions, simultaneously. The detected beam intensity is expected to be enough for turbulence measurements in almost the entire plasma region when the electron density is up to 1 × 1019 m−3 by selecting appropriate ion species for the probe beam. Each detector has three channels 10 mm apart, allowing measurement of local structures of micro-scale turbulence. Therefore, using the HIBPs on the PLATO tokamak will enable both local and global properties of plasma turbulence to be investigated, simultaneously.
Binding and stability of MgO monomers on anatase TiO2(101)
Authors: Doudin Nassar , Collinge Greg , Persaud Rudradatt R. , Gurunathan Pradeep Kumar , Lee Mal-Soon , Glezakou Vassiliki-Alexandra , Dixon David A. , Rousseau Roger , Dohnálek Zdenek 
Published: May 2021

In catalysis, MgO is often used to modify the acid–base properties of support oxides and to stabilize supported metal atoms and particles on oxides. In this study, we show how the sublimation of MgO powder can be used to deposit MgO monomers, hither on anatase TiO2(101). A combination of x-ray electron spectroscopy, high-resolution scanning tunneling microscopy, and density functional theory is employed to gain insight into the MgO monomer binding, electronic and vibrational properties, and thermal stability. In the most stable configuration, the Mg and O of the MgO monomer bind to two surface oxygens and one undercoordinated surface titanium, respectively. The additional binding weakens the Mg–O monomer bond and makes Mg more ionic. The monomers are thermally stable up to 600 K, where the onset of diffusion into the TiO2 bulk is observed. The monomeric MgO species on TiO2(101) represent an ideal atomically precise system with modified acid–base properties and will be employed in our future catalytic studies.
Language and ethnobiological skills decline precipitously in Papua New Guinea, the world’s most linguistically diverse nation
Authors: Kik Alfred , Adamec Martin , Aikhenvald Alexandra Y. , Bajzekova Jarmila , Baro Nigel , Bowern Claire , Colwell Robert K. , Drozd Pavel , Duda Pavel , Ibalim Sentiko , Jorge Leonardo R. , Mogina Jane , Ruli Ben , Sam Katerina , Sarvasy Hannah , Saulei Simon , Weiblen George D. , Zrzavy Jan , Novotny Vojtech 
Published: May 2021

SignificanceAround the world, more than 7,000 languages are spoken, most of them by small populations of speakers in the tropics. Globalization puts small languages at a disadvantage, but our understanding of the drivers and rate of language loss remains incomplete. When we tested key factors causing language attrition among Papua New Guinean students speaking 392 different indigenous languages, we found an unexpectedly rapid decline in their language skills compared to their parents and predicted further acceleration of language loss in the next generation. Language attrition was accompanied by decline in the traditional knowledge of nature among the students, pointing to an uncertain future for languages and biocultural knowledge in the most linguistically diverse place on Earth.
Steering the governance of artificial intelligence: national strategies in perspective
Authors: Radu Roxana 
Published: May 2021

ABSTRACT
As more and more governments release national strategies on artificial intelligence (AI), their priorities and modes of governance become more clear. This study proposes the first comprehensive analysis of national approaches to AI from a hybrid governance perspective, reflecting on the dominant regulatory discourses and the (re)definition of the public-private ordering in the making. It analyses national strategies released between 2017 and 2019, uncovering the plural institutional logics at play and the public-private interaction in the design of AI governance, from the drafting stage to the creation of new oversight institutions. Using qualitative content analysis, the strategies of a dozen countries (as diverse as Canada and China) are explored to determine how a hybrid configuration is set in place. The findings show a predominance of ethics-oriented rather than rule-based systems and a strong preference for functional indetermination as deliberate properties of hybrid AI governance.
Early-stage bone regeneration of hyaluronic acid supplemented with porous 45s5 bioglass-derived granules: an injectable system
Authors: Im Soo Bin , Tripathi Garima , Le Thi Thao Thanh , Lee Byong Taek 
Published: May 2021

Abstract
In the present study, an injectable bone substitute system which utilized porous bioglass (BG)-derived granules supplemented with hyaluronic acid (Hya), was evaluated. Hya plays ultimate role in wound healing, promoting cell motility. The BG were synthesized by a simple and low sintering temperature process without any foreign phase incorporation. Furthermore, the physical properties in the porous scaffold were optimized to investigate the in vitro and in vivo performance. The porous BG60 scaffolds system showed excellent bioactivity in an in vitro simulated body fluid test in which the ions dissolved from the composite materials influenced apatite growth, countered the acidic pH, and increased material degradation. In an in vitro study with pre-osteoblasts cells (MC3T3-E1), the porous scaffold supported cell adhesion and proliferation. A post-implantation study conducted in femoral defects showed implant degradation and surprisingly fast bone formation just after 2 weeks of implantation. Initial in vivo degradation of Hya promotes releasing ions which regulates the bone forming cells, clues to tissue repair, and regeneration. On the other hand it also prevent the scattering of BG granule after grafting at implant site. The faster dissolution of the porous BG scaffold increased the resorption of the composite material and hence, facilitated bone tissue regeneration. Our findings suggest that the porous BG scaffold could potentially be used as an injectable bone substitute for fast, early bone regeneration applications.