bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative assessment of linear least‐squares, nonlinear least‐squares, and Patlak graphical method for regional and local quantitative tracer kinetic modeling in cerebral dynamic 18F‐FDG PET
Authors: Ben Bouallègue Fayçal , Vauchot Fabien , Mariano‐Goulart Denis
Published: December 2018

Purpose

Dynamic 18F‐FDG PET allows quantitative estimation of cerebral glucose metabolism both at the regional and local (voxel) level. Although sensitive to noise and highly computationally expensive, nonlinear least‐squares (NLS) optimization stands as the reference approach for the estimation of the kinetic model parameters. Nevertheless, faster techniques, including linear least‐squares (LLS) and Patlak graphical method, have been proposed to deal with high resolution noisy data, representing a more adaptable solution for routine clinical implementation. Former research investigating the relative performance of the available algorithms lack precise evaluation of kinetic parameter estimates under realistic acquisition conditions.

Methods

The present study aims at the systematic comparison of the feasibility and pertinence of kinetic modeling of dynamic cerebral 18F‐FDG PET using NLS, LLS, and Patlak method, based on numerical simulations and patient data. Numerical simulations were used to study the bias and variance of K1 and Ki parameters estimation under representative noise levels. Patient data allowed to assess the concordance between the three methods at the regional and voxel scale, and to evaluate the robustness of the estimations with respect to patient head motion.

Results and Conclusions

Our findings indicate that at the regional level NLS and LLS provide kinetic parameter estimates (K1 and Ki) with similar bias and variance characteristics (K1 bias ± relative standard deviation [RSD] 0.0 ± 5.1% and 0.1% ± 4.9% for NLS and LLS respectively, Ki bias ± RSD 0.1% ± 4.5% and −0.7% ± 4.4% for NLS and LLS respectively). NLS estimates appear, however, to be slightly less sensitive to patient motion. At the voxel level, provided that patient motion is negligible or corrected, LLS offers an appealing alternative solution for local K1 mapping. It yields K1 estimates that are highly correlated, with high correlation with NLS values (Pearson's r = 0.95 on actual data) within computations times less than two orders of magnitude lower. Last, Patlak method appears as the most robust and accurate technique for the estimation of Ki values at the regional and voxel scale, with or without head motion. It provides low bias/low variance Ki quantification (bias ± RSD −1.5 ± 9.5% and −4.1 ± 19.7% for Patlak and NLS respectively) as well as smooth parametric images suitable for visual assessment.
A fast inverse direct aperture optimization algorithm for intensity‐modulated radiation therapy
Authors: MacFarlane Michael , Hoover Douglas A. , Wong Eugene , Goldman Pedro , Battista Jerry J. , Chen Jeff Z.
Published: December 2018

Purpose

The goal of this work was to develop and evaluate a fast inverse direct aperture optimization (FIDAO) algorithm for IMRT treatment planning and plan adaptation.

Methods

A previously proposed fluence map optimization algorithm called fast inverse dose optimization (FIDO) was extended to optimize the aperture shapes and weights of IMRT beams. FIDO is a very fast fluence map optimization algorithm for IMRT that finds the global minimum using direct matrix inversion without unphysical negative beam weights. In this study, an equivalent second‐order Taylor series expansion of the FIDO objective function was used, which allowed for the objective function value and gradient vector to be computed very efficiently during direct aperture optimization, resulting in faster optimization. To evaluate the speed gained with FIDAO, a proof‐of‐concept algorithm was developed in MATLAB using an interior‐point optimization method to solve the reformulated aperture‐based FIDO problem. The FIDAO algorithm was used to optimize four step‐and‐shoot IMRT cases: on the AAPM TG‐119 phantom as well as a liver, prostate, and head‐and‐neck clinical cases. Results were compared with a conventional DAO algorithm that uses the same interior‐point method but using the standard formulation of the objective function and its gradient vector.

Results

A substantial gain in optimization speed was obtained with the prototype FIDAO algorithm compared to the conventional DAO algorithm while producing plans of similar quality. The optimization time (number of iterations) for the prototype FIDAO algorithm vs the conventional DAO algorithm was 0.3 s (17) vs 56.7 s (50); 2.0 s (28) vs 134.1 s (57); 2.5 s (26) vs 180.6 s (107); and 6.7 s (20) vs 469.4 s (482) in the TG‐119 phantom, liver, prostate, and head‐and‐neck examples, respectively.

Conclusions

A new direct aperture optimization algorithm based on FIDO was developed. For the four IMRT test cases examined, this algorithm executed approximately 70–200 times faster without compromising the IMRT plan quality.
Neutrophil trafficking to lymphoid tissues: physiological and pathological implications
Authors: Voisin Mathieu‐Benoit , Nourshargh Sussan
Published: December 2018

Recent advances have provided evidence for the involvement of neutrophils in both innate and adaptive immunity, robustly challenging the old dogma that neutrophils are short‐lived prototypical innate immune cells solely involved in acute responses to microbes and exerting collateral tissue damage. There is now ample evidence showing that neutrophils can migrate into different compartments of the lymphoid system where they contribute to the orchestration of the activation and/or suppression of lymphocyte effector functions in homeostasis and during chronic inflammation, such as autoimmune disorders and cancer. In support of this notion, neutrophils can generate a wide range of cytokines and other mediators capable of regulating the survival, proliferation and functions of both T and B cells. In addition, neutrophils can directly engage with lymphocytes and promote antigen presentation. Furthermore, there is emerging evidence of the existence of distinct and diverse neutrophil phenotypes with immunomodulatory functions that characterise different pathological conditions, including chronic and autoimmune inflammatory conditions. The aim of this review is to discuss the mechanisms implicated in neutrophil trafficking into the lymphoid system and to provide an overview of the immuno‐regulatory functions of neutrophils in health and disease in the context of adaptive immunity. Copyright © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
High‐throughput sequencing identifies aetiology‐dependent differences in ductular reaction in human chronic liver disease
Authors: Govaere Olivier , Cockell Simon , Van Haele Matthias , Wouters Jasper , Van Delm Wouter , Van den Eynde Kathleen , Bianchi Arianna , van Eijsden Rudy , Van Steenbergen Werner , Monbaliu Diethard , Nevens Frederik , Roskams Tania
Published: December 2018

Ductular reaction (DR) represents the activation of hepatic progenitor cells (HPCs) and has been associated with features of advanced chronic liver disease; yet it is not clear whether these cells contribute to disease progression and how the composition of their micro‐environment differs depending on the aetiology. This study aimed to identify HPC‐associated signalling pathways relevant in different chronic liver diseases using a high‐throughput sequencing approach. DR/HPCs were isolated using laser microdissection from patient samples diagnosed with HCV or primary sclerosing cholangitis (PSC), as models for hepatocellular or biliary regeneration. Key signals were validated at the protein level for a cohort of 56 patients (20 early and 36 advanced stage). In total, 330 genes were significantly differentially expressed between the HPCs in HCV and PSC. Recruitment and homing of inflammatory cells were distinctly different depending on the aetiology. HPCs in PSC were characterised by a response to oxidative stress (e.g. JUN, VNN1) and neutrophil‐attractant chemokines (CXCL5, CXCL6, IL‐8), whereas HPCs in HCV were identified by T‐ and B‐lymphocyte infiltration. Moreover, we found that communication between HPCs and macrophages was aetiology driven. In PSC, a high frequency of CCL28‐positive macrophages was observed in the portal infiltrate, already in early disease in the absence of advanced fibrosis, while in HCV, HPCs showed a strong expression of the macrophage scavenger receptor MARCO. Interestingly, DR/HPCs in PSC showed more deposition of ECM (e.g. FN1, LAMC2, collagens) compared to HCV, where an increase of pro‐invasive genes (e.g. PDGFRA, IGF2) was observed. Additionally, endothelial cells in the vicinity of DR/HPCs showed differential immunopositivity (e.g. IGF2 and INHBA expression). In conclusion, our data shine light on the role of DR/HPCs in immune signalling, fibrogenesis and angiogenesis in chronic liver disease. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of graphene treated with cyclohexyl diamine by diazonium reaction on cure kinetics, mechanical, thermal, and physical properties of natural rubber/graphene nanocomposite foam
Authors: Charoeythornkhajhornchai Pollawat , Samthong Chavakorn , Somwangthanaroj Anongnat
Published: December 2018

The influence of functionalization of cyclohexyl diamine onto the graphene surface via diazonium reaction on the cure kinetics as well as morphology, mechanical, thermal and physical properties of natural rubber (NR)/graphene nanocomposite foam was investigated. The surface functionalization of graphene was confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy, and thermogravimetric analysis (TGA). Without an addition of blowing agent, the vulcanized NR composites containing cyclohexyl amine‐treated graphene showed not obvious different dispersion of graphene nanoplatelets than those containing untreated graphene as confirmed by transmission electron microscopy micrographs. Although the addition of untreated graphene could accelerate the sulfur vulcanization rate of NR nanocomposite foam due to the high thermal conductivity of graphene particle, and the remaining oxygen functional groups on the surface of graphene, the amines from cyclohexyl diamine on the treated graphene could react with carboxylic and epoxide group on the surface of graphene leading to a reduction of reactive oxygen functional groups on graphene surface and in turn slowed vulcanization rate. The fast vulcanization rate in untreated graphene system led to small bubble size in the NR nanocomposite foams. In contrast, the treated graphene system showed high tensile strength and low thermal expansion coefficient owing to low cell density. Finally, the defect on the graphene surface after functionalization was detected by Raman spectroscopy; this resulted in poor thermal conductivity for the treated graphene composite system. POLYM. COMPOS., 40:E1766–E1776, 2019. © 2018 Society of Plastics Engineers
Kinetics of formation of microstructure in polyurethane foams infused with micro and nanosized carbonaceous fillers
Authors: Pikhurov Dmitry V. , Zuev Vjacheslav V.
Published: December 2018

The kinetics of catalyzed by dibutyltin dilaurate reaction of polyurethane foam synthesis infused with 1 wt% of fillers was studied in dependence of Type 1D (nanosized [multi‐wall carbon nanotubes] or macrosized [carbon fibers]) or 2D (thermoexpanded graphite) carbonaceous fillers by IR spectroscopy and optical microscopy. It is shown that the foaming reaction has two stages: the first stage being a first‐order reaction, and the second stage a second‐order reaction. The mean diameter of the bubbles and the bubble size distribution has been determined during the process of foaming. It is shown that the presence of 2D fillers leads to a decrease in the mean diameter of the bubbles. POLYM. ENG. SCI., 59:941–948, 2019. © 2018 Society of Plastics Engineers
Improved environmental stability, electrical and EMI shielding properties of vapor‐grown carbon fiber‐filled polyaniline‐based nanocomposite
Authors: Kumar Vipin , Muflikhun Muhammad Akhsin , Yokozeki Tomohiro
Published: December 2018

An all polymeric electrically conductive thermoset adhesive resin system is prepared for future lightning strike protection applications. Polyaniline (PANI)‐based hybrid nano‐composite is prepared by incorporating high apparent‐density type vapor grown carbon fiber (VGCF‐H) as additional conductive filler. Electrical, mechanical and electromagnetic interference (EMI) shielding properties of PANI‐dodecylbenzene sulfonic acid (DBSA), and divinylbenzene (DVB) system are improved with addition of VGCF‐H. Different weight percentages of VGCF‐H in the PANI‐DBSA/DVB matrix, are studied, and their effect on composite's properties are investigated. Electrical conductivity up to 1.89 S/cm with the addition of 5 wt% VGCF‐H is achieved, which is almost 300% improvement compared with previous system. However, the maximum flexural modulus is obtained at 3 wt% of VGCF‐H. The change in the electronic structure of PANI with the addition of VGCF‐H is investigated using Fourier transform infrared (FT‐IR) analysis. Rheological study and Differential scanning calorimetry analysis were employed to show the effect of VGCF‐H concentration on curing profile of the nanocomposites. EMI shielding properties of the composite with and without VGCF‐H are measured in X‐band frequencies and compared. Composite with 5 wt% VGCF‐H has shown EMI shielding effectiveness about 51 dB in X‐band, which is higher than the composite without VGCF‐H (around 22 dB). POLYM. ENG. SCI., 59:956–963, 2019. © 2018 Society of Plastics Engineers
Does Intrinsic Disorder in Proteins Favor Their Interaction with Lipids?
Authors: Deryusheva Evgenia , Nemashkalova Ekaterina , Galloux Marie , Richard Charels‐Adrien , Eléouët Jean‐François , Kovacs Denis , Van Belle Karo , Tompa Peter , Uversky Vladimir , Permyakov Sergei
Published: December 2018

Intrinsically disordered proteins (IDPs) are implicated in a range of human diseases, some of which are associated with the ability to bind to lipids. Although the presence of solvent‐exposed hydrophobic regions in IDPs should favor their interactions with low‐molecular‐weight hydrophobic/amphiphilic compounds, this hypothesis has not been systematically explored as of yet. In this study, the analysis of the DisProt database with regard to the presence of lipid‐binding IDPs (LBIDPs) reveals that they comprise, at least, 15% of DisProt entries. LBIDPs are classified into four groups by ligand type, functional categories, domain structure, and conformational state. 57% of LBIDPs are classified as ordered according to the CH‐CDF analysis, and 70% of LBIDPs possess lengths of disordered regions below 50%. To investigate the lipid‐binding properties of IDPs for which lipid binding is not reported, three proteins from different conformational groups are rationally selected. They all are shown to bind linoleic (LA) and oleic (OA) acids with capacities ranging from 9 to 34 LA/OA molecules per protein molecule. The association with LA/OA causes the formation of high‐molecular‐weight lipid–protein complexes. These findings suggest that lipid binding is common among IDPs, which can favor their involvement in lipid metabolism.
C―H···O hydrogen bonding interactions for sterically hindered phenols and their phenoxyl radicals
Authors: Wang Jinhu , Liu Chunli , Liu Xuejing , Shao Linjun , Zhang Xian‐Man
Published: December 2018

Sterically hindered phenols have been widely used as chain‐breaking antioxidants in chemical and polymeric industries, and the remarkable stabilities of their phenoxyl radicals are generally attributed to the steric effects and resonance stabilization of the unpaired electron into the aromatic ring. Non‐covalent interaction (NCI) analysis shows that there are four intramolecular C―H···O hydrogen bonds between oxygen atom and theortho t‐butyl C―H bonds for the sterically hindered phenoxyl radicals and their phenolic precursors. The C―H···O hydrogen bonds can be directly visualized and quantified from the reduced density gradient NCI isosurfaces and atoms‐in‐molecules analysis, respectively. Furthermore, the phenolic O―H bond strength decreases gradually with increasing volume of theorthoalkyl substituents in three different phenol model systems (Table 5). The nice linear correlation of the O―H bond dissociation enthalpies with the Taft's steric parameters (Figure 8) provides additional evidences to support formation of the intramolecular C―H···O hydrogen bonds between oxygen atom and theortho t‐alkyl C―H bonds.
Geomorphology of Gullies at Thomas Lee Inlet, Devon Island, Canadian High Arctic
Authors: Godin Etienne , Osinski Gordon R. , Harrison Tanya N. , Pontefract Alexandra , Zanetti Michael
Published: December 2018

Slopes in and around Thomas Lee Inlet (Devon Island, Nunavut, Canada) are eroded by means of gullying, yet the driving factors, such as the nature of the substrate and availability of different sources for water, influencing gully morphology remain poorly understood. Here we investigate the factors that contribute to gully formation using a combination of satellite mapping, field observations and statistical analysis of morphological data. In total, 161 gullies were mapped within the 126 km2 study area. Factors linked to gullies, such as the nature of its substrate and the presence of glaciers, were integrated into a spatial geodatabase. A Factor Analysis of Mixed Data performed on the geodatabase was used to discriminate which factors may influence gully geometry. Our results show that the type of geological formation has a strong impact on gully slope. In addition, supplemental sources of water are often found near alcoves of the steep, longer and mature gullies, and levees often form in their aprons. Immature debris flow‐like gullies were dryer and found on short and variable (from steep to gentle) slopes. This detailed study of the rocky and arid Thomas Lee Inlet plateaus and slopes provides the first insight into gullied slopes as a hydrological component connecting upland units to downslope in this area.
Rectify Effect of Pedot:PSS/WS2 Heterostructure
Authors: Chan Ka Ho , Ng Sheung Mei , Wong Hon Fai , Leung Chi Wah , Mak Chee Leung
Published: December 2018

Recently, devices based on organic and two‐dimensional (2D) materials have been recognized as the easiest way to fabricate hybrid 2D van der Waals (vdW) heterojunction devices for electronic and optoelectronic applications. Depositing organic materials on 2D materials is typically demonstrated by thermal evaporation using high voltage and vacuum systems. In this paper, a simple way to fabricate organic/n‐2D heterostructures, where Pedot:PSS is chosen to be the organic material due to its high conductivity, excellent film forming ability and good stability, while WS2 is selected as the n‐2D material due to its well‐known properties has been presented. By systematically studying the gate dependent and temperature‐dependent I–V characteristics of the Pedot:PSS/WS2 heterojunctions, it is demonstrated that the device shows a diode‐like behavior with rectification ratio (RF) of ≈5 and a turn on voltage of ≈2 V at room temperature (RT). Furthermore, the rectification ratio of the junction reaches up to 103 using a back‐gate bias voltage (Vgs) of 20 V together with drain–source voltage (Vds) ranging from −4 to 4 V. On the basis of the results, it is demonstrated that this simple technique of fabricating organic/2D vdW heterojunctions can extend to other organics and 2D materials.
Assessing the mechanisms governing the daytime evolution of marine stratocumulus using large‐eddy simulation
Authors: McMichael Lucas A. , Mechem David B. , Wang Shouping , Wang Qing , Kogan Yefim L. , Teixeira João
Published: December 2018

Large‐eddy simulation (LES) output for a case of thin stratocumulus off the coast of California is examined in a mixed‐layer analysis framework to identify the specific mechanisms responsible for governing the evolution of the cloud system. An equation for cloud‐base height tendency isolates the individual cloud‐modulating mechanisms that control the evolution of boundary‐layer liquid‐water static energy (Sl) and total water mixing ratio (qT). With a suitable spin‐up procedure, the control simulation performs admirably compared with observed estimates of liquid water content, vertical velocity variance, and radiative fluxes sampled during an aircraft field campaign. Investigation of the cloud response to various environmental forcing scenarios was addressed through a suite of sensitivity simulations, including variations in subsidence velocity, surface fluxes, wind shear near the inversion, and radiative forcing. In the control simulation, rising cloud‐base tendencies are associated with entrainment warming/drying and short‐wave absorption, whereas lowering cloud‐base tendencies are driven by long‐wave cooling. Even in the presence of substantial afternoon solar heating, entrainment fluxes remained active. The thin cloud demonstrated unexpected resiliency, with mixed‐layer analysis indicating that, as the short‐wave flux decreases later in the afternoon, the relative contribution of long‐wave cooling often becomes large enough to offset entrainment warming/drying and result in a reversal of cloud‐base tendency. The evolution of cloud‐base tendency is found to be insensitive to the net radiative flux divergence for most of the simulations (liquid water path ranging from ~10–50 g/m2). Error analysis in comparison with LES Sl and qT budgets suggests that our method of entrainment flux calculation could be improved by a more complete understanding of entrainment‐layer physics.
Open‐Circuit Ultrafast Generation of Nanoscopic Toroidal Moments: The Swift Phase Generator
Authors: Wätzel Jonas , Berakdar Jamal
Published: December 2018

Efficient and flexible schemes for a swift, field‐free control of the phase in quantum devices have far‐reaching impact on energy‐saving operation of quantum computing, data storage, and sensoring nanodevices. A novel approach for an ultrafast generation of a field‐free vector potential that is tunable in duration, sign, and magnitude, allowing to impart non‐invasive, spatiotemporally controlled changes to the quantum nature of nanosystems is reported. The method relies on triggering a steady‐state toroidal moment in a donut‐shaped nanostructure that serves as a vector‐potential generator and quantum phase modulator. Irradiated by moderately intense, few cycle THz pulses with appropriately shaped polarization states, the nano donut is brought to a steady‐state where a nearby object does not experience electric or magnetic fields but feels the photo‐generated vector potential. Designing the time structure of the driving THz pulses allows for launching picosecond trains of vector potentials which is the key for a contact‐free optimal control of quantum coherent states. This research can trigger a new class of ultrafast quantum devices operated and switched in an energy‐efficient, contact and field‐free manner, enabling new techniques for use in quantum information, magnetic nanostructures, and superconducting tunnel junctions as well as in toroidally ordered systems and multiferroics.
Design and implementation of a hierarchical clustering‐based CMAC‐PID controller using closed‐loop data
Authors: Liao Yuntao , Koiwai Kazushige , Yamamoto Toru
Published: December 2018

A cerebellar model articulation controller (CMAC) neural network is an excellent choice for optimizing the control performance for nonlinear systems. CMAC can be used to generate control inputs and controller parameters, acting as a controller parameter ‘tuner’. The most desirable feature of a CMAC is its generalization ability. When CMAC is utilized as a controller parameter ‘tuner’, the CMAC‐based controller facilitates the improvement of control performance for untrained signals. A conventional CMAC achieves higher accuracy by increasing the number of labels for each weight table. However, as the number of labels increases, the requirement for memory increases rapidly and generalization ability decreases. Thus, a CMAC in which the number of labels for each weight table can be decided individually is proposed, allowing layers with more labels to boost accuracy and layers with less labels to improve the generalization ability of the CMAC. Furthermore, hierarchical clustering is employed to determine the labels in each weight table, allowing the input space to be quantized adaptively. Additionally, the output of a CMAC is controller gain, and fictitious reference iterative tuning (FRIT) is employed to adjust the weights of CMAC in an off‐line manner. In this work, the controller used is a proportional‐integral‐derivative (PID) controller. Finally, the effectiveness of the proposed method is verified numerically through some simulations and experiments. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Double‐layer optimization of home energy management systems with volt–watt functions
Authors: Dao Van Tu , Ishii Hideo , Hayashi Yasuhiro
Published: December 2018

The increasing number of rooftop solar panels and home‐scale batteries in residential areas enables an emerging energy market for homeowners to take part in. By optimizing the energy usage at home, the surplus amount can be exported to the grid for selling to intermediaries like aggregators at a higher price than a feed‐in tariff set by the government. Though not trading with the power utility, the resulting reverse power flow may cause the service voltage to increase and violate the set upper limit. To avoid this problem, the utility asks all grid‐connected inverters to reduce the reverse power by installing volt–watt functions. Unfortunately, this kind of function may reduce the profits of the homeowners since the exported energy cannot match the amount committed to the aggregator. Our research addresses this issue by proposing a double‐layer optimization for each home energy management system. The first layer optimizes the one‐day home energy usage with consideration of uncertainty in the predicted data of load and solar irradiance to estimate the highest home profit as possible. Then, the second layer tries to reduce the high reverse power with minimal impact on the profit found in the first layer. A simulation of a distribution system shows that the proposed method is able to flatten the power profile flowing reversely to the grid and reduce the drawbacks of volt–watt functions. Homeowners are recommended to practice the proposed method when trading the surplus energy. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A system for supporting practice of lure casting using acceleration and gyroscope sensors
Authors: Taniguchi Yoshiaki , Uranishi Ryota
Published: December 2018

For practice of lure casting, information on fly distance of lure and information on rod motion are helpful. In this letter, we propose a system for supporting practice of lure casting. In our system, a sensor device with acceleration and gyroscope sensors is attached at a rod and it collects sensor data during casting motion to estimate fly distance. The estimated fly distance and sensor data are displayed at a user's mobile device. Through experimental evaluations, we confirmed that the mean absolute error of fly distance estimation of our proposed system is 1.376 m. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Perinatal mortality and morbidity in triplet pregnancy according to chorionicity: systematic review and meta‐analysis
Authors: Curado J. , D'antonio F. , Papageorghiou A. T. , Bhide A. , Thilaganathan B. , Khalil A.
Published: December 2018

Objective

The incidence of perinatal mortality and morbidity in triplet pregnancies according to chorionicity is yet to be established. The aim of this systematic review was to quantify perinatal mortality and morbidity in trichorionic triamniotic (TCTA), dichorionic triamniotic (DCTA) and monochorionic triamniotic (MCTA) triplets.

Methods

MEDLINE, EMBASE and CINAHL databases were searched in December 2017 for literature published in English describing outcomes of DCTA, TCTA and/or MCTA triplet pregnancies. Primary outcomes were intrauterine death (IUD), neonatal death, perinatal death (PND) and gestational age at birth. Secondary outcomes comprised respiratory, neurological and infectious morbidity, as well as a composite score of neonatal morbidity. Data regarding outcomes were extracted from the included studies. Random‐effects meta‐analysis was used to estimate the risk of mortality and morbidity and to compute the difference in gestational age at birth between TCTA and DCTA triplet pregnancies.

Results

Nine studies (1373 triplet pregnancies, of which 1062 were TCTA, 261 DCTA and 50 MCTA) were included in the analysis. The risk of PND was higher in DCTA than in TCTA triplet pregnancies (odds ratio (OR), 3.3 (95% CI, 1.3–8.0)), mainly owing to the higher risk of IUD in DCTA triplet pregnancies (OR, 4.6 (95% CI, 1.8–11.7)). There was no difference in gestational age at birth between TCTA and DCTA triplets (mean difference, 1.1 weeks (95% CI, –0.3 to 2.5 weeks); I2 = 85%; P = 0.12). Neurological morbidity occurred in 2.0% (95% CI, 1.1–3.3%) of TCTA and in 11.6% (95% CI, 1.1–40.0%) of DCTA triplets. Respiratory and infectious morbidity affected 28.3% (95% CI, 20.7–36.8%) and 4.2% (95% CI, 2.8–5.9%) of TCTA and 34.0% (95% CI, 21.5–47.7%) and 7.1% (95% CI, 2.7–13.3%) of DCTA triplets, respectively. The incidence of composite morbidity in TCTA and DCTA triplets was 29.6% (95% CI, 21.1–38.9%) and 34.0% (95% CI, 21.5–47.7%), respectively. When translating these figures into a risk analysis, the risk of neurological morbidity (OR, 5.4 (95% CI, 1.6–18.3)) was significantly higher in DCTA than in TCTA triplets, while there was no significant difference in the other morbidities explored. Only one study reported on outcomes of MCTA pregnancies, hence, no formal comparison with the other groups was performed.

Conclusion

DCTA triplets are at higher risk of perinatal mortality and morbidity than are TCTA triplets. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Does levator ani hiatal area configuration affect pelvic organ prolapse?
Authors: Xuan Y. , Friedman T. , Dietz H. P.
Published: December 2018

Objective

Levator ani trauma and hiatal overdistension have been shown to be associated with female pelvic organ prolapse (POP); however, the role of the shape of the levator hiatus in POP has not been examined to date. The aim of this study was to investigate the association between the configuration of the levator ani hiatus and POP.

Methods

This was a retrospective study of 547 women who attended a tertiary urogynecological center for symptoms of pelvic floor and lower urinary tract dysfunction between October 2014 and August 2016. All women underwent a standardized interview and prolapse assessment using the International Continence Society (ICS) Pelvic Organ Prolapse Quantification (POP‐Q) method and four‐dimensional translabial ultrasound (TLUS). Measurements of the hiatal anteroposterior diameter (APD), coronal diameter (CD) and hiatal area (HA), at rest and on maximal Valsalva maneuver, and those of organ descent were performed offline at a later date by an investigator blinded to all other data. Hiatal configuration was defined as the ratio APD/CD. Associations between HA and HA adjusted by APD/CD at rest and on maximal Valsalva and symptoms and signs of prolapse were analyzed statistically using logistic regression modelling.

Results

The mean age of the women was 54 ± 13.6 (range, 16–89) years. Of the 547 women included, 241 (44%) presented with prolapse symptoms. Clinically significant POP was detected in 406 (74%) patients and significant prolapse on TLUS was detected in 331 (61%). Hiatal ballooning was observed in 310 (57%) women and this was strongly associated with signs and symptoms of POP. HA at rest and on Valsalva was associated with significant POP both on clinical examination and on TLUS. Adjusted odds ratios for hiatal shape showed no effect of the hiatal configuration on the association between HA and POP.

Conclusion

Hiatal shape does not seem to influence the association between HA and symptoms and signs of prolapse. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Formatting biological big data for modern machine learning in drug discovery
Authors: Duran‐Frigola Miquel , Fernández‐Torras Adrià , Bertoni Martino , Aloy Patrick
Published: December 2018

Biological data is accumulating at an unprecedented rate, escalating the role of data‐driven methods in computational drug discovery. This scenario is favored by recent advances in machine learning algorithms, which are optimized for huge datasets and consistently beat the predictive performance of previous art, rapidly approaching human expert reasoning. The urge to couple biological data to cutting‐edge machine learning has spurred developments in data integration and knowledge representation, especially in the form of heterogeneous, multiplex and semantically‐rich biological networks. Today, thanks to the propitious rise in knowledge embedding techniques, these large and complex biological networks can be converted to a vector format that suits the majority of machine learning implementations. Here, we explain why this can be particularly transformative for drug discovery where, for decades, customary chemoinformatics methods have employed vector descriptors of compound structures as the standard input of their prediction tasks. A common vector format to represent biology and chemistry may push biological information into most of the existing steps of the drug discovery pipeline, boosting the accuracy of predictions and uncovering connections between small molecules and other biological entities such as targets or diseases.

This article is categorized under:

Computer and Information Science > Databases and Expert Systems

Computer and Information Science > Chemoinformatics
Reconsidering Sovereignty, Ownership and Consent in Natural Resource Contracts: From Concepts to Practice
Authors: Cotula Lorenzo
Published: December 2018

A wave of commercial investments in the natural resource sectors has rekindled debates about the place of contracts in the interface between economic governance and control over natural resources. Contracts between investors and states have provided the legal basis for many natural resource projects. They have also formed the object of renegotiations and disputes. Meanwhile, community-investor agreements have emerged as a strategy to promote local support for the business or advance local claims to natural resources. This chapter interrogates the fundamental parameters on which resource-related contracting rests. It first examines, based on positive law, the foundations of natural resource contracts, focusing on the notions of sovereignty, ownership and consent. This conceptual exploration highlights that, while consent underpins the contract, the legal construction of (state) sovereignty and (resource) ownership sets parameters for the expression of consent—namely, the actors whose consent is required, the processes through which consent is formed and manifested, and the bounds within which consent can lawfully operate. The chapter then distils some practical implications for natural resource contracts, focusing on illustrative issues relating both to the substantive and procedural dimensions of investor-state contracts, and to reframing the contracting process around a wider range of resource right holders and affected actors. The findings provide pointers for piecing together the diverse and possibly conflicting commercial and non-commercial interests that are at stake in natural resource contracts.
ON OPTIMAL HETEROGENEOUS COMPONENTS GROUPING IN SERIES-PARALLEL AND PARALLEL-SERIES SYSTEMS
Authors: Ling Xiaoliang , Wei Yinzhao , Li Ping
Published: December 2018

In this paper, we consider optimal components grouping in series–parallel and parallel–series systems composed of k subsystems. All components in each subsystem are drawn from a heterogeneous population consisting of m different subpopulations. Firstly, we show that when one allocation vector is majorized by another one, then the series–parallel (parallel–series) system corresponding to the first (second) vector is more reliable than that of the other. Secondly, we study the impact of changes in the number of subsystems on the system reliability. Finally, we study the influence of the selection probabilities of subpopulations on the system reliability.
Empirical Run‐Time Bias Correction for Antarctic Regional Climate Projections With a Stretched‐Grid AGCM
Authors: Krinner Gerhard , Beaumet Julien , Favier Vincent , Déqué Michel , Brutel‐Vuilmet Claire
Published: December 2018

This work presents snapshot simulations of the late 20th and late 21st century Antarctic climate under the RCP8.5 scenario carried out with an empirically bias‐corrected global atmospheric general circulation model (AGCM), forced with bias‐corrected sea‐surface temperatures and sea ice and run with about 100‐km resolution over Antarctica. The bias correction substantially improves the simulated mean late 20th century climate. The simulated atmospheric circulation of the bias‐corrected model compares very favorably to the best available AMIP (Atmospheric Model Intercomparison Project)‐type climate models. The simulated interannual circulation variability is improved by the bias correction. Depending on the metric, a slight improvement or degradation is found in the simulated variability on synoptic timescales. The simulated climate change over the 21st century is broadly similar in the corrected and uncorrected versions of the atmospheric model, and atmospheric circulation patterns are not geographically “pinned” by the applied bias correction. These results suggest that the method presented here can be used for bias‐corrected climate projections. Finally, the authors discuss different possible choices in terms of the place of bias corrections and other intermediate steps in the modeling chain leading from global coupled climate simulations to impact assessment.
Energy autonomous electronic skin
Authors: García Núñez Carlos , Manjakkal Libu , Dahiya Ravinder
Published: December 2018

Energy autonomy is key to the next generation portable and wearable systems for several applications. Among these, the electronic-skin or e-skin is currently a matter of intensive investigations due to its wider applicability in areas, ranging from robotics to digital health, fashion and internet of things (IoT). The high density of multiple types of electronic components (e.g. sensors, actuators, electronics, etc.) required in e-skin, and the need to power them without adding heavy batteries, have fuelled the development of compact flexible energy systems to realize self-powered or energy-autonomous e-skin. The compact and wearable energy systems consisting of energy harvesters, energy storage devices, low-power electronics and efficient/wireless power transfer-based technologies, are expected to revolutionize the market for wearable systems and in particular for e-skin. This paper reviews the development in the field of self-powered e-skin, particularly focussing on the available energy-harvesting technologies, high capacity energy storage devices, and high efficiency power transmission systems. The paper highlights the key challenges, critical design strategies, and most promising materials for the development of an energy-autonomous e-skin for robotics, prosthetics and wearable systems. This paper will complement other reviews on e-skin, which have focussed on the type of sensors and electronics components.
Soundness and completeness of quantum root-mean-square errors
Authors: Ozawa Masanao
Published: December 2018

Defining and measuring the error of a measurement is one of the most fundamental activities in experimental science. However, quantum theory shows a peculiar difficulty in extending the classical notion of root-mean-square (rms) error to quantum measurements. A straightforward generalization based on the noise-operator was used to reformulate Heisenberg’s uncertainty relation on the accuracy of simultaneous measurements to be universally valid and made the conventional formulation testable to observe its violation. Recently, its reliability was examined based on an anomaly that the error vanishes for some inaccurate measurements, in which the meter does not commute with the measured observable. Here, we propose an improved definition for a quantum generalization of the classical rms error, which is state-dependent, operationally definable, and perfectly characterizes accurate measurements. Moreover, it is shown that the new notion maintains the previously obtained universally valid uncertainty relations and their experimental confirmations without changing their forms and interpretations, in contrast to a prevailing view that a state-dependent formulation for measurement uncertainty relation is not tenable.
Characterizing the multipartite continuous-variable entanglement structure from squeezing coefficients and the Fisher information
Authors: Qin Zhongzhong , Gessner Manuel , Ren Zhihong , Deng Xiaowei , Han Dongmei , Li Weidong , Su Xiaolong , Smerzi Augusto , Peng Kunchi
Published: December 2018

Understanding the distribution of quantum entanglement over many parties is a fundamental challenge of quantum physics and is of practical relevance for several applications in the field of quantum information. The Fisher information is widely used in quantum metrology since it is related to the quantum gain in metrology measurements. Here, we use methods from quantum metrology to microscopically characterize the entanglement structure of multimode continuous-variable states in all possible multi-partitions and in all reduced distributions. From experimentally measured covariance matrices of Gaussian states with 2, 3, and 4 photonic modes with controllable losses, we extract the metrological sensitivity as well as an upper separability bound for each partition. An entanglement witness is constructed by comparing the two quantities. Our analysis demonstrates the usefulness of these methods for continuous-variable systems and provides a detailed geometric understanding of the robustness of cluster-state entanglement under photon losses.
On-chip transverse-mode entangled photon pair source
Authors: Feng Lan-Tian , Zhang Ming , Xiong Xiao , Chen Yang , Wu Hao , Li Ming , Guo Guo-Ping , Guo Guang-Can , Dai Dao-Xin , Ren Xi-Feng
Published: December 2018

Integrated entangled photon pair source is an essential resource for both fundamental investigations and practical applications of quantum information science. Currently there have been several types of entanglement, among which the transverse-mode entanglement is becoming attractive because of its unique advantages. Here, we report an on-chip transverse-mode entangled photon pair source via the spontaneous four-wave mixing processes in a multimode silicon waveguide. Transverse-mode photon pairs are verified over multiple frequency channels within a bandwidth of ~2 THz, and a maximally entangled Bell state is also produced with a net fidelity of 0.96 ± 0.01. Our entangled photon pair source is the key element for quantum photonics based on transverse-mode, and also has the possibility to extend to higher-dimensional Hilbert space. Furthermore, the transverse-mode entanglement can be converted coherently to path and polarization entanglement, which paves the way to realizing highly complex quantum photonic circuits with multiple degrees of freedom.
Biological control of an agricultural pest protects tropical forests
Authors: Wyckhuys K. A. G. , Hughes A. C. , Buamas C. , Johnson A. C. , Vasseur L. , Reymondin L. , Deguine J. -P. , Sheil D.
Published: December 2018

Though often perceived as an environmentally-risky practice, biological control of invasive species can restore crop yields, ease land pressure and thus contribute to forest conservation. Here, we show how biological control against the mealybug Phenacoccus manihoti (Hemiptera) slows deforestation across Southeast Asia. In Thailand, this newly-arrived mealybug caused an 18% decline in cassava yields over 2009–2010 and an escalation in prices of cassava products. This spurred an expansion of cassava cropping in neighboring countries from 713,000 ha in 2009 to > 1 million ha by 2011: satellite imagery reveals 388%, 330%, 185% and 608% increases in peak deforestation rates in Cambodia, Lao PDR, Myanmar and Vietnam focused in cassava crop expansion areas. Following release of the host-specific parasitoid Anagyrus lopezi (Hymenoptera) in 2010, mealybug outbreaks were reduced, cropping area contracted and deforestation slowed by 31–95% in individual countries. Hence, when judiciously implemented, insect biological control can deliver substantial environmental benefits.
Unipolar to ambipolar semiconductivity switching in charge transfer cocrystals of 2,7-di-tert-butylpyrene
Authors: Mandal Arkalekha , Swain Pravasini , Nath Bhaskar , Sau Sudip , Mal Prasenjit
Published: December 2018

Charge transfer cocrystals of 2,7-di-tert-butylpyrene donor and tetracyanoquinodimethane, tetracyanobenzene and 1,3-dinitrobenzene acceptor exhibited switchable semi-conductivity.
Lutidinium-based ionic liquids for efficient dissolution of cellulose
Authors: Samikannu Rakesh , Shukla Shashi Kant , Samikannu Ajaikumar , Mikkola Jyri-Pekka
Published: December 2018

Herein, we have studied the potential of lutidinium-based ionic liquids in the dissolution of cellulose as confirmed by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and 13C CP/MAS NMR, spectroscopic methods.
A high-performance asymmetric supercapacitor based on Ni3S2-coated NiSe arrays as positive electrode
Authors: Ye Beirong , Gong Chao , Huang Miaoliang , Ge Jinhua , Fan Leqing , Lin Jianming , Wu Jihuai
Published: December 2018

Cotton-like Ni3S2-coated NiSe rod composite electrode was synthesized by cyclic voltammetry electrodeposition with satisfactory electrochemical performance.
Synthesis of spirooxindoles fused with pyrazolo-tetrahydropyridinone and coumarin-dihydropyridine-pyrazole tetracycles by reaction medium dependent isatin-based multicomponent reactions
Authors: Mishra Richa , Jana Asim , Panday Anoop Kumar , Choudhury Lokman H.
Published: December 2018

A reaction medium dependent three-component reaction of isatin, 4-hydroxycoumarin and aminopyrazole/aminoisoxazole has been reported under microwave heating conditions for the synthesis of two different types of fused spirooxindoles.
Covalently functionalized heterostructured carbon by redox-active p-phenylenediamine molecules for high-performance symmetric supercapacitors
Authors: He Yuanyuan , Yang Xia , An Ning , Wang Xiaotong , Yang Yuying , Hu Zhongai
Published: December 2018

p-Phenylenediamine (PPD) as a novel organic electrochemically active material for supercapacitors has been covalently grafted onto dissected carbon nanotubes (DCNTs) via a facile single-step reflux method.
CuSbSe2/TiO2: novel type-II heterojunction nano-photocatalyst
Authors: Kshirsagar Anuraj S. , Khanna Pawan K.
Published: December 2018

A novel nano-hybrid using a small-band-gap CuSbSe2 and wide-band-gap TiO2 is formed via microwave and thermal methods for efficient photocatalytic degradation of organic dyes.
Self-assembled polymeric micelles as amphiphilic particulate emulsifiers for controllable Pickering emulsions
Authors: Wang Feng , Tang Juntao , Liu Hui , Yu Guipeng , Zou Yingping
Published: December 2018

This review summarizes the important achievements of self-assembled micelles based on amphiphilic block and random copolymers for controllable Pickering emulsions.
Selective synthesis of aryl thioamides and aryl-α-ketoamides from α-oxocarboxylic acids and tetraalkylthiuram disulfides: an unexpected chemoselectivity from aryl sulfonyl chlorides
Authors: Lai Miao , Wu Zhiyong , Wang Yizhi , Zheng Ying , Zhao Mingqin
Published: December 2018

Tosyl chloride-controlled generation of thioamides and α-ketoamides via base-promoted decarboxylative reaction of α-oxocarboxylic acids with tetraalkylthiuram disulfides has been established.