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Abstract A switching‐angle‐based hybrid modulation method of full wind speed and low carrier wave ratio for direct‐drive permanent‐magnet wind power generation system is proposed here, which order to improve the control performance of wind turbines in the full wind speed range. The combination manner of the proposed method is based on the harmonic distortion rate of the stator current, a modulation mode with a higher carrier wave ratio is adopted within the maximum switching frequency allowed by the system, the switching angle from optimized synchronous modulation also is introduced. In order to solve the problem of current impact caused by switching different modulation modes, the switching strategy between different modulation modes is developed from the perspective of harmonic current. And the sectors are redivided for the problem of sudden change in carrier wave ratio during switching, which improve the control effect of permanent‐magnet synchronous wind generator when changing the modulations modes. Finally, the feasibility and correctness of the proposed method are verified by theoretical analysis and simulation.

Ag3PO4/g-C3N4 photocatalytic composites were synthesized via calcination and hydrothermal synthesis for the degradation of rhodamine B (RhB) in wastewater, and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS). The degradation of RhB by Ag3PO4/g-C3N4 composites was investigated to evaluate their photocatalytic performance and cyclic degradation stability. The experimental results showed that the composites demonstrated notable photocatalytic activity and stability during degradation. Their high degradation efficiency is attributed to the Z-scheme transfer mechanism, in which the electrons in the Ag3PO4 conduction band and the holes in the g-C3N4 valence band are annihilated by heterojunction recombination, which greatly limits the recombination of photogenerated electrons and holes in the catalyst and enhances the activity of the composite photocatalyst. In addition, measurements of photocurrent (PC) and electrochemical impedance spectroscopy (EIS) confirmed that the efficient charge separation of photo-generated charges stemmed from strong interactions at the close contact interface. Finally, the mechanism for catalytic enhancement in the composite photocatalysts was proposed based on hole and radical trapping experiments, electron paramagnetic resonance (EPR) analysis, and work function evaluation.

A novel metal-free synthesis of 3-substituted isocoumarins through a sequential O-acylation/Wittig reaction has been established. The readily accessible (2-carboxybenzyl)-triphenylphosphonium bromide and diverse chlorides produced various 1H-isochromen-1-one in the presence of triethylamine, employing sequential O-acylation and an intramolecular Wittig reaction of acid anhydride. Reactions using these facile conditions have exhibited high functional group tolerance and excellent yields (up to 90%). Moreover, the fluorescence properties of isocoumarin derivatives were evaluated at the theoretical and experimental levels to determine their potential application in fluorescent materials. These derivatives have good photoluminescence in THF with a large Stokes shift and an absolute fluorescence quantum yield of up to 14%.

ABSTRACTBackground Dental caries is a chronic, multifactorial and biofilm-mediated oral bacterial infection affecting almost every age group and every geographical region. Streptococcus mutans is considered an important pathogen responsible for the initiation and development of dental caries. It produces exopolysaccharides in situ to promote the colonization of cariogenic bacteria and coordinate dental biofilm development.Objective The understanding of the regulatory mechanism of S. mutans biofilm formation can provide a theoretical basis for the prevention and treatment of caries.Design At present, an increasing number of studies have identified many regulatory systems in S. mutans that regulate biofilm formation, including second messengers (e.g. c-di-AMP, Ap4A), transcription factors (e.g. EpsR, RcrR, StsR, AhrC, FruR), two-component systems (e.g. CovR, VicR), small RNA (including sRNA0426, srn92532, and srn133489), acetylation modifications (e.g. ActG), CRISPR-associated proteins (e.g. Cas3), PTS systems (e.g. EIIAB), quorum-sensing signaling system (e.g. LuxS), enzymes (including Dex, YidC, CopZ, EzrA, lmrB, SprV, RecA, PdxR, MurI) and small-molecule metabolites.Results This review summarizes the recent progress in the molecular regulatory mechanisms of exopolysaccharides synthesis and biofilm formation in S. mutans.

Efficient and stable electrode materials are urgently required for wastewater treatment in the electrocatalytic degradation of toxic and refractory organic pollutants. Ti3+ self-doping black TiO2 nanotube arrays (Ti/B-TiO2-NTs) as an interlayer were used for preparing a novel PbO2 electrode via an electrochemical reduction technology, and a sodium dodecyl sulfate (SDS)-modified PbO2 catalytic layer was successfully achieved via an electrochemical deposition technology. The physicochemical characterization tests showed that the Ti/B-TiO2-NTs/PbO2-SDS electrodes have a denser surface and finer grain size with the introduction of Ti3+ in the interlayer of Ti/TiO2-NTs and the addition of SDS in the active layer of PbO2. The electrochemical characterization results showed that the Ti3+ self-doping black Ti/TiO2-NTs/PbO2-SDS electrode had higher oxygen evolution potential (2.11 V vs. SCE), higher electrode stability, smaller charge-transfer resistance (6.74 Ω cm−2), and higher hydroxyl radical production activity, leading to it possessing better electrocatalytic properties. The above results indicated that the physicochemical and electrochemical characterization of the PbO2 electrode were all enhanced significantly with the introduction of Ti3+ and SDS. Furthermore, the Ti/B-TiO2-NTs/PbO2-SDS electrodes displayed the best performance on the degradation of methylene blue (MB) in simulated wastewater via bulk electrolysis. The removal efficiency of MB and the chemical oxygen demand (COD) could reach about 99.7% and 80.6% under the optimal conditions after 120 min, respectively. The pseudo-first-order kinetic constant of the Ti/B-TiO2-NTs/PbO2-SDS electrode was 0.03956 min−1, which was approximately 3.18 times faster than that of the Ti/TiO2-NTs/PbO2 electrode (0.01254 min−1). In addition, the Ti/B-TiO2-NTs/PbO2-SDS electrodes showed excellent stability and reusability. The degradation mechanism of MB was explored via the experimental identification of intermediates. In summary, the Ti3+ self-doping black Ti/TiO2-NTs/PbO2-SDS electrode is a promising electrode in treating wastewater.

In this study, we have successfully constructed Ag3PO4/Ag/g-C3N4 heterojunctions via the hydrothermal method, which displays a wide photo-absorption range. The higher photocurrent intensity of Ag3PO4/Ag/g-C3N4 indicates that the separation efficiency of the photogenerated electron–hole pairs is higher than that of both Ag3PO4 and Ag/g-C3N4 pure substances. It is confirmed that the efficient separation of photogenerated electron–hole pairs is attributed to the heterojunction of the material. Under visible light irradiation, Ag3PO4/Ag/g-C3N4-1.6 can remove MO (~90%) at a higher rate than Ag3PO4 or Ag/g-C3N4. Its degradation rate is 0.04126 min−1, which is 4.23 and 6.53 times that of Ag/g-C3N4 and Ag3PO4, respectively. After five cycles of testing, the Ag3PO4/Ag/g-C3N4 photocatalyst still maintained high photocatalytic activity. The excellent photocatalysis of Ag3PO4/Ag/g-C3N4-1.6 under ultraviolet-visible light is due to the efficient separation of photogenerated carriers brought about by the construction of the Ag3PO4/Ag/g-C3N4 heterostructure. Additionally, Ag3PO4/Ag/g-C3N4 specimens can be easily recycled with high stability. The effects of hydroxyl and superoxide radicals on the degradation process of organic compounds were studied using electron paramagnetic resonance spectroscopy and radical quenching experiments. Therefore, the Ag3PO4/Ag/g-C3N4 composite can be used as an efficient and recyclable UV-vis spectrum-driven photocatalyst for the purification of organic pollutants.

Abstract The application of deep learning algorithms for medical diagnosis in the real world faces challenges with transparency and interpretability. The labeling of large-scale samples leads to costly investment in developing deep learning algorithms. The application of human prior knowledge is an effective way to solve these problems. Previously, we developed a deep learning system for glaucoma diagnosis based on a large number of samples that had high sensitivity and specificity. However, it is a black box and the specific analytic methods cannot be elucidated. Here, we establish a hierarchical deep learning system based on a small number of samples that comprehensively simulates the diagnostic thinking of human experts. This system can extract the anatomical characteristics of the fundus images, including the optic disc, optic cup, and appearance of the retinal nerve fiber layer to realize automatic diagnosis of glaucoma. In addition, this system is transparent and interpretable, and the intermediate process of prediction can be visualized. Applying this system to three validation datasets of fundus images, we demonstrate performance comparable to that of human experts in diagnosing glaucoma. Moreover, it markedly improves the diagnostic accuracy of ophthalmologists. This system may expedite the screening and diagnosis of glaucoma, resulting in improved clinical outcomes.

Abstract Three‐phase interleaved LLC resonant converters are preferably employed to realize high efficiency and high power density in the application of On‐board Charger. The parameter design of LLC resonant converter with wide range output has always been rigorous and difficult. Compared with the common time‐domain model, a high‐accuracy time domain analysis is adopted to analyze the interaction between three phases in detail. This method improves the accuracy of the design results by adding the interaction analysis. According to the operation mode analysis, transformer's turn ratio, resonant inductor, magnetic inductor and resonant capacitor are optimized based on the design principle of minimizing the conduction loss. Finally, the modified efficiency‐oriented optimal method of wide output range LLC resonant converter is proposed and its design results is validated by a 6.6 kW prototype. The efficiency of the design using proposed method is significantly improved than the results of the common time‐domain model.

There are more than 20 known melanoma susceptibility genes. Here, using a massively parallel reporter assay, the authors identify risk-associated variants that alter gene transcription, and demonstrate that expression of one such gene, MX2, leads to the promotion of melanoma in a zebrafish model.

Abstract Polymer electrolyte membrane fuel cells can generate high power using a potentially green fuel (H2) and zero emissions of greenhouse gas (CO2). However, significant mass transport resistances in the interface region of the membrane electrode assemblies (MEAs), between the membrane and the catalyst layers remains a barrier to achieving MEAs with high power densities and long‐term stabilities. Here, a 3D‐interfacial zipping concept is presented to overcome this challenge. Vinylbenzyl‐terminated bi‐cationic quaternary‐ammonium‐based polyelectrolyte is employed as both the anionomer in the anion‐exchange membrane (AEM) and catalyst layers. A quaternary‐ammonium‐containing covalently locked interface is formed by thermally induced inter‐crosslinking of the terminal vinyl groups. Ex situ evaluation of interfacial bonding strength and in situ durability tests demonstrate that this 3D‐zipped interface strategy prevents interfacial delamination without any sacrifice of fuel cell performance. A H2/O2 AEMFC test demonstration shows promisingly high power densities (1.5 W cm−2 at 70 °C with 100% RH and 0.2 MPa backpressure gas feeds), which can retain performances for at least 120 h at a usefully high current density of 0.6 A cm−2.

This paper presents a hierarchical multinomial latent model with G0 distribution for synthetic aperture radar (SAR) image semantic segmentation. The model considers the scattering statistics and multiscale characteristics of the SAR images. Specifically, a 2-D discrete wavelet transform is used to construct a quad-tree structure, and a hierarchical multinomial latent model is used for semantic segmentation. The hierarchical model can capture local and global characteristics of the SAR images. Additionally, statistical distributions of SAR images are discussed. The flexible G0 distribution is substituted into the hierarchical multinomial latent model for the segmentation of various types of land covers. Moreover, the developed Bayesian inference on the quad-tree structure is incorporated into our approach. The semantic segmentation map is obtained from an initialization, bottom-up, and top-down probability computations. In this way, the underlying spatial structure information is effectively propagated. Our experiments compare the proposed approach, other multinomial latent model-based methods, and Markov random field-based methods. The experiments are conducted from a series of synthetic and real SAR images, where the segmentation results demonstrate that our approach is robust to the noise in most cases, obtains the best result among the compared methods and improves the state-of-the-art segmentation performance.

Genetic variants at multiple loci of chr5p15.33 have been associated with susceptibility to numerous cancers. Here the authors show that the association of one of these loci may be explained by a variant, rs36115365, influencing telomerase reverse transcriptase (TERT) expression via ZNF148.

The Rao-Blackwellized particle filtering (RBPF) offers a general tracking framework with linear/nonlinear state space models, which outperforms the standard particle filtering in nonlinear and non-Gaussian tracking scenarios. Unfortunately, in conventional radar systems, the observations contain no information about the linear part of target state. In these cases, the RBPF algorithm fails to catch the real trajectories, because we cannot obtain the enough information to correctly update the linear part of target state in the tracking procedure. To overcome such an issue, this paper proposes a Kalman estimation-based BRPF (KE-BRPF) algorithm. In KE-RBPF, the correlation between linear and nonlinear parts of target state is investigated. Benefitting from such investigation, we derive a new set of formulea to present the correlation in terms of means and variances. By utilizing these formulas, our KE-RBPF algorithm correctly tracks the linear part of target state based on the nonlinear one. Finally, the simulation results verify that, our KE-RBPF performs better than other state-of-the-art tracking methods in nonlinear and non-Gaussian radar tracking scenarios, with at least 18% reduction in terms of the means and central tendency of error of tracking root-mean-square-error.

In this paper, we propose a novel method to detect saliency on face images. In our method, face and facial features are extracted as two top-down feature channels, linearly integrated with three traditional bottom-up features of color, intensity, and orientation, to yield final saliency map of a face image. By conducting an eye tracking experiment, a database with human fixations on 510 face images is obtained for analyzing the fixation distribution on face region. We find that fixations on face regions can be well modeled by a Gaussian mixture model (GMM), corresponding to face and facial features. Accordingly, we model face saliency by the GMM, learned from the training data of our database. In addition, we investigate that the weights of face feature channels rely on the face size in images, and the relationship between the weights and face size is, therefore, estimated by learning from the training data of our eye tracking database. The experimental results validate that our learning-based method is capable of dramatically improving the accuracy of saliency detection on face images over other ten state-of-the-art methods. Finally, we apply our saliency detection method to compress face images, with an improvement on visual quality or saving on bit-rate over the existing image encoder.

This paper proposes three game-theoretic approaches for coalition formation in cooperative networks with simultaneous wireless information and power transfer. To improve the reception reliability of destinations with poor channel conditions, we first divide destinations in the network into two types: Type I and Type II. Type I destinations refer to the destinations with capability of successful information decoding and energy harvesting, which serve as relays to help other destinations. Type II destinations have poor connections to the source and hence compete to obtain help from Type I destinations. Accordingly, cooperative relaying strategies for the two types of destinations are proposed on the basis of coalition formation game. First, we propose to utilize the dynamic programming (DP) approach to obtain the optimal coalition structure in the network, though at the cost of heavy time and storage complexity. Then, two distributed hedonic coalition formation (DHCF) approaches are developed to generate coalition structures, which are more efficient than the DP approach. Simulation results show that all proposed approaches outperform the non-cooperative one (i.e., direct link transmission). The results also illustrate that the DP approach achieves the largest data rate and lowest outage probability for destinations, and the DHCF approaches achieve near-to-optimal performance.

As the latest video coding standard, High Efficiency Video Coding (HEVC) tremendously improves the encoding efficiency compared with the preceding H.264/AVC standard, but at the cost of higher encoding complexity. This huge encoding complexity makes the implementation of HEVC intractable on live videos. For coping with this problem, two major challenges need to be solved: 1) How to accurately reduce the encoding complexity to achieve the target complexity? and 2) How to maintain the video quality after encoding complexity reduction? To solve these two challenges, we propose, in this paper, a hierarchical complexity control approach of HEVC. For the first goal, the complexity control is implemented in two levels to assure the control accuracy. In the largest coding unit (LCU) level, we adjust the maximum depths of LCUs in a frame to reduce the encoding complexity to the target. Since each frame has numerous LCUs, and each LCU can choose its maximum depth from one of the four maximum depths, the large degree of freedom contributes to the high control accuracy. However, there may be still some errors. These errors can be compensated in the frame level by a proposed frame level complexity control algorithm. For the second goal, one objective weight map and one subjective weight map are proposed to use in the process of complexity control to keep the objective and subjective video quality simultaneously. Finally, The experimental results show that our approach outperforms other state-of-the-art approaches, in terms of both control accuracy and video quality.

Nature Communications 8: Article number: 15034 (2017); Published: 27 May 2017; Updated: 5 March 2018 The original version of this Article contained an error in the spelling of two members of the GenoMEL Consortium, Joan Anton Puig-Butille and Pol Gimenez-Xavier, which were incorrectly given as Joan-Anton Puig Butille and Pol Gimenez Xavier respectively.

For monitoring burst events in a kind of reactive wireless sensor networks (WSNs), a multipath routing protocol (MRP) based on dynamic clustering and ant colony optimization (ACO) is proposed.. Such an approach can maximize the network lifetime and reduce the energy consumption. An important attribute of WSNs is their limited power supply, and therefore some metrics (such as energy consumption of communication among nodes, residual energy, path length) were considered as very important criteria while designing routing in the MRP. Firstly, a cluster head (CH) is selected among nodes located in the event area according to some parameters, such as residual energy. Secondly, an improved ACO algorithm is applied in the search for multiple paths between the CH and sink node. Finally, the CH dynamically chooses a route to transmit data with a probability that depends on many path metrics, such as energy consumption. The simulation results show that MRP can prolong the network lifetime, as well as balance of energy consumption among nodes and reduce the average energy consumption effectively.

Partner and localizer of BRCA2 (PALB2) interacts with BRCA2 to enable double strand break repair through homologous recombination. Similar to BRCA2, germline mutations in PALB2 have been shown to predispose to Fanconi anaemia as well as pancreatic and breast cancer. The PALB2/BRCA2 protein interaction, as well as the increased melanoma risk observed in families harbouring BRCA2 mutations, makes PALB2 a candidate for melanoma susceptibility. In order to assess PALB2 as a melanoma predisposition gene, we sequenced the entire protein-coding sequence of PALB2 in probands from 182 melanoma families lacking pathogenic mutations in known high penetrance melanoma susceptibility genes: CDKN2A, CDK4, and BAP1. In addition, we interrogated whole-genome and exome data from another 19 kindreds with a strong family history of melanoma for deleterious mutations in PALB2. Here we report a rare known deleterious PALB2 mutation (rs118203998) causing a premature truncation of the protein (p.Y1183X) in an individual who had developed four different cancer types, including melanoma. Three other family members affected with melanoma did not carry the variant. Overall our data do not support a case for PALB2 being associated with melanoma predisposition.

Patients with pancreatic cancer have dismal prognoses, and novel therapies are urgently needed. Mutations of the KRAS oncogene occur frequently in pancreatic cancer and represent an attractive target. Direct targeting of the predominant KRAS pathways have been challenging and research into therapeutic strategies have been now refocused on pathways downstream of KRAS, phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK [MEK]). We hypothesized that concurrent inhibition of the PI3K and MEK pathways would result in synergistic antitumor activity, as it would circumvent the compensatory feedback loop between the two pathways. We investigated the combined effect of the PI3K inhibitor, GDC0941, and the MEK inhibitor, AZD6244, on cell viability, apoptosis and cell signaling in a panel of pancreatic cancer cell lines. An in vivo analysis was conducted on pancreatic cancer xenografts. While BxPC-3 (KRAS wild type) and MIA PaCa-2 (KRAS mutated) cell lines were sensitive to GDC0941 and AZD6244 as single agents, synergistic inhibition of tumor cell growth and induction of apoptosis were observed in both cell lines when the two drugs were combined. Interestingly, phosphorylation of the cap-dependent translational components, 4E-binding protein (p-4E-BP1) and S6 was found to be closely associated with sensitivity to GDC0941 and AZD6244. In BxPC-3 cell xenografts, survival differences were observed between the control and the AZD6244, GDC0941, and combination groups. Our study provides the rationale for concurrent targeting of the PI3K and MEK pathways, regardless of KRAS status, and suggests that phosphorylation of 4E-BP1and S6 can serve as a predictive biomarker for response to treatment.

In multi-target tracking, the key problem lies in estimating the number and states of individual targets, in which the challenge is the time-varying multi-target numbers and states. Recently, several multi-target tracking approaches, based on the sequential Monte Carlo probability hypothesis density (SMC-PHD) filter, have been presented to solve such a problem. However, most of these approaches select the transition density as the importance sampling (IS) function, which is inefficient in a nonlinear scenario. To enhance the performance of the conventional SMC-PHD filter, we propose in this paper two approaches using the cubature information filter (CIF) for multi-target tracking. More specifically, we first apply the posterior intensity as the IS function. Then, we propose to utilize the CIF algorithm with a gating method to calculate the IS function, namely CISMC-PHD approach. Meanwhile, a fast implementation of the CISMC-PHD approach is proposed, which clusters the particles into several groups according to the Gaussian mixture components. With the constructed components, the IS function is approximated instead of particles. As a result, the computational complexity of the CISMC-PHD approach can be significantly reduced. The simulation results demonstrate the effectiveness of our approaches.

In the title compound, [Co(C12H13N2O3)2], the CoII ion is situated on a twofold rotation axis and is coordinated by two N and two O atoms from two symmetry-related Schiff base 2-(cyclopentyliminomethyl)-4-nitrophenolate ligands (L) in a distorted tetrahedral geometry. The cyclopentyl ring in L is disordered over two conformations in a 0.640 (19):0.360 (19) ratio.

CXCL12 is a pleiotropic chemokine involved in multiple different processes such as immune regulation, inflammatory responses, and cancer development. CXCL12 is also a potent chemokine involved in chemoattraction of T cells to the site of infection or inflammation. Mammalian target of rapamycin (mTOR) is a serine-threonine kinase that modulates different cellular processes, such as metabolism, nutrient sensing, protein translation, and cell growth. The role of mTOR in CXCL12-mediated resting T cell migration has yet to be elucidated.Rapamycin, an inhibitor of mTOR, significantly inhibits CXCL12 mediated migration of both primary human resting T cells and human T cell leukemia cell line CEM. p70(S6K1), an effector molecule of mTOR signaling pathway, was knocked down by shRNA in CEM cells using a lentiviral gene transfer system. Using p70(S6K1) knock down cells, we demonstrate the role of mTOR signaling in T cell migration both in vitro and in vivo.Our data demonstrate a new role for mTOR in CXCL12-induced T cell migration, and enrich the current knowledge regarding the clinical use of rapamycin.