bluuebunny/crossref_metadata_2025 huggingface dataset:
DANNP: an efficient artificial neural network pruning tool
Authors: Alshahrani Mona , Soufan Othman , Magana-Mora Arturo , Bajic Vladimir B.
Published: November 2017

Background

Artificial neural networks (ANNs) are a robust class of machine learning models and are a frequent choice for solving classification problems. However, determining the structure of the ANNs is not trivial as a large number of weights (connection links) may lead to overfitting the training data. Although several ANN pruning algorithms have been proposed for the simplification of ANNs, these algorithms are not able to efficiently cope with intricate ANN structures required for complex classification problems.

Methods

We developed DANNP, a web-based tool, that implements parallelized versions of several ANN pruning algorithms. The DANNP tool uses a modified version of the Fast Compressed Neural Network software implemented in C++ to considerably enhance the running time of the ANN pruning algorithms we implemented. In addition to the performance evaluation of the pruned ANNs, we systematically compared the set of features that remained in the pruned ANN with those obtained by different state-of-the-art feature selection (FS) methods.

Results

Although the ANN pruning algorithms are not entirely parallelizable, DANNP was able to speed up the ANN pruning up to eight times on a 32-core machine, compared to the serial implementations. To assess the impact of the ANN pruning by DANNP tool, we used 16 datasets from different domains. In eight out of the 16 datasets, DANNP significantly reduced the number of weights by 70%–99%, while maintaining a competitive or better model performance compared to the unpruned ANN. Finally, we used a naïve Bayes classifier derived with the features selected as a byproduct of the ANN pruning and demonstrated that its accuracy is comparable to those obtained by the classifiers trained with the features selected by several state-of-the-art FS methods. The FS ranking methodology proposed in this study allows the users to identify the most discriminant features of the problem at hand. To the best of our knowledge, DANNP (publicly available at www.cbrc.kaust.edu.sa/dannp) is the only available and on-line accessible tool that provides multiple parallelized ANN pruning options. Datasets and DANNP code can be obtained at www.cbrc.kaust.edu.sa/dannp/data.php and https://doi.org/10.5281/zenodo.1001086.
HCV core antigen is an alternative marker to HCV RNA for evaluating active HCV infection: implications for improved diagnostic option in an era of affordable DAAs
Authors: Wasitthankasem Rujipat , Vichaiwattana Preeyaporn , Auphimai Chompoonut , Siripon Nipaporn , Klinfueng Sirapa , Tangkijvanich Pisit , Vongpunsawad Sompong , Poovorawan Yong
Published: November 2017

The core antigen of the hepatitis C virus (HCV Ag) presents an alternative marker to HCV RNA when screening patients for HCV viremia. This study sought to evaluate the utility of HCV Ag as a marker to assess active HCV infection in individuals residing in an HCV-endemic area. From 298 HCV-seropositive individuals evaluated for the presence of anti-HCV antibody, HCV Ag and HCV RNA, anti-HCV antibody was detected in 252 individuals (signal-to-cutoff ratios ≥5), HCV RNA was detected in 222 individuals (88%), and HCV Ag was reactive (≥3 fmol/L) in 220 individuals (87%). HCV genotype 1, 3, and 6 were identified. HCV Ag significantly correlated with HCV RNA irrespective of HCV genotype and/or HBV co-infection (log HCV RNA = 2.67 + 0.95 [log HCV Ag], R2 = 0.890, p < 0.001). To predict HCV viremia (HCV Ag ≥ 3 fmol/L), the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 99%, 99%, 100%, 100% and 97%, respectively. We concluded that HCV Ag was a good surrogate marker for HCV RNA and could be used to diagnose active HCV infection in a resource-limited setting. As a result, a cost-effective strategy for screening and identifying active HCV carriers using HCV Ag detection would enable more patients access to efficacious and increasingly affordable direct-acting antivirals (DAAs) for the treatment of HCV infection.
Extended beta distributions open the access to fast gating in bilayer experiments—assigning the voltage‐dependent gating to the selectivity filter
Authors: Rauh Oliver , Hansen Ulf‐Peter , Mach Sebastian , Hartel Andreas J.W. , Shepard Kenneth L. , Thiel Gerhard , Schroeder Indra
Published: November 2017

Lipid bilayers provide many benefits for ion channel recordings, such as control of membrane composition and transport molecules. However, they suffer from high membrane capacitance limiting the bandwidth and impeding analysis of fast gating. This can be overcome by fitting the deviations of the open‐channel noise from the baseline noise by extended beta distributions. We demonstrate this analysis step‐by‐step by applying it to the example of viral K+ channels (Kcv), from the choice of the gating model through the fitting process, validation of the results, and what kinds of results can be obtained. These voltage sensor‐less channels show profoundly voltage‐dependent gating with dwell times in the closed state of about 50 μs. Mutations assign it to the selectivity filter.
The Plasma Sheet as Natural Symmetry Plane for Dipolarization Fronts in the Earth's Magnetotail
Authors: Frühauff D. , Glassmeier K.‐H.
Published: November 2017

In this work, observations of multispacecraft mission Time History of Events and Macroscale Interactions during Substorms are used for statistical investigation of dipolarization fronts in the near‐Earth plasma sheet of the magnetotail. Using very stringent criteria, 460 events are detected in almost 10 years of mission data. Minimum variance analysis is used to determine the normal directions of the phase fronts, providing evidence for the existence of a natural symmetry of these phenomena, given by the neutral sheet of the magnetotail. This finding enables the definition of a local coordinate system based on the Tsyganenko model, reflecting the intrinsic orientation of the neutral sheet and, therefore, the dipolarization fronts. In this way, the comparison of events with very different background conditions is improved. Through this study, the statistical results of Liu, Angelopoulos, Runov, et al. (2013) are both confirmed and extended. In a case study, the knowledge of this plane of symmetry helps to explain the concave curvature of dipolarization fronts in the XZ plane through phase propagation speeds of magnetoacoustic waves. A second case study is presented to determine the central current system of a passing dipolarization front through a constellation of three spacecraft. With this information, a statistical analysis of spacecraft observations above and below the neutral sheet is used to provide further evidence for the neutral sheet as the symmetry plane and the central current system. Furthermore, it is shown that the signatures of dipolarization fronts are under certain conditions closely related to that of flux ropes, indicating a possible relationship between these two transient phenomena.
Ellipsoidal Correction in GRACE Surface Mass Change Estimation
Authors: Li Jin , Chen Jianli , Li Ziang , Wang Song‐Yun , Hu Xiaogong
Published: November 2017

The Earth's shape is much closer to an ellipsoid than a sphere. The commonly used spherical approximation in mass change inversion is expected to cause bias by the spherical harmonic (SH) solutions from Gravity Recovery and Climate Experiment (GRACE), especially in high‐latitude regions where significant present‐day ice losses occur. This bias, or ellipsoidal correction, reaches up to 8% from the evaluation by simulations based on synthetic mass change rate models. Further evaluation using 14 plus years of GRACE monthly SH solutions (from April 2002 to December 2016) indicates that the ellipsoidal correction is also noticeable in the total mass change time series over polar regions. Before and after the ellipsoidal correction, the estimated linear rates from mass change time series differ by 4.3%, 4.7%, 5.2%, 5.7%, and 6.6% for five selected regions over Greenland, Antarctic Peninsula, Amundsen Sea Embayment, Alaska glacier, and Svalbard Islands, respectively. Although with amplitudes likely below the current GRACE's uncertainty level, these differences are consistently negative over the five regions. This indicates that the spherical approximation leads to systematic underestimation for polar mass change rates. Thus, the ellipsoidal correction needs to be considered for more precise mass recovery with GRACE SH solutions. It also depends on spatial scales of mass change signals (the smaller the spatial scale, the larger the correction). To more reliably estimate high‐latitude surface mass changes by GRACE SH solutions, the ellipsoidal correction is recommended, especially for ice‐loss signals over polar regions.
First Simulations of Designing Stratospheric Sulfate Aerosol Geoengineering to Meet Multiple Simultaneous Climate Objectives
Authors: Kravitz Ben , MacMartin Douglas G. , Mills Michael J. , Richter Jadwiga H. , Tilmes Simone , Lamarque Jean‐Francois , Tribbia Joseph J. , Vitt Francis
Published: November 2017

We describe the first simulations of stratospheric sulfate aerosol geoengineering using multiple injection locations to meet multiple simultaneous surface temperature objectives. Simulations were performed using CESM1(WACCM), a coupled atmosphere‐ocean general circulation model with fully interactive stratospheric chemistry, dynamics (including an internally generated quasi‐biennial oscillation), and a sophisticated treatment of sulfate aerosol formation, microphysical growth, and deposition. The objectives are defined as maintaining three temperature features at their 2020 levels against a background of the RCP8.5 scenario over the period 2020–2099. These objectives are met using a feedback mechanism in which the rate of sulfur dioxide injection at each of the four locations is adjusted independently every year of simulation. Even in the presence of uncertainties, nonlinearities, and variability, the objectives are met, predominantly by SO2 injection at 30°N and 30°S. By the last year of simulation, the feedback algorithm calls for a total injection rate of 51 Tg SO2 per year. The injections are not in the tropics, which results in a greater degree of linearity of the surface climate response with injection amount than has been found in many previous studies using injection at the equator. Because the objectives are defined in terms of annual mean temperature, the required geongineering results in “overcooling” during summer and “undercooling” during winter. The hydrological cycle is also suppressed as compared to the reference values corresponding to the year 2020. The demonstration we describe in this study is an important step toward understanding what geoengineering can do and what it cannot do.
Sensitivity of Aerosol Distribution and Climate Response to Stratospheric SO2 Injection Locations
Authors: Tilmes Simone , Richter Jadwiga H. , Mills Michael J. , Kravitz Ben , MacMartin Douglas G. , Vitt Francis , Tribbia Joseph J. , Lamarque Jean‐Francois
Published: November 2017

Injection of SO2 into the stratosphere has been proposed as a method to, in part, counteract anthropogenic climate change. So far, most studies investigated injections at the equator or in a region in the tropics. Here we use Community Earth System Model version 1 Whole Atmosphere Community Climate Model (CESM1(WACCM)) to explore the impact of continuous single grid point SO2 injections at seven different latitudes and two altitudes in the stratosphere on aerosol distribution and climate. For each of the 14 locations, 3 different constant SO2 emission rates were tested to identify linearity in aerosol burden, aerosol optical depth, and climate effects. We found that injections at 15°N and 15°S and at 25 km altitude have equal or greater effect on radiation and surface temperature than injections at the equator. Nonequatorial injections transport SO2 and sulfate aerosols more efficiently into middle and high latitudes and result in particles of smaller effective radius and larger aerosol burden in middle and high latitudes. Injections at 15°S produce the largest increase in global average aerosol optical depth and increase the change in radiative forcing per Tg SO2/yr by about 15% compared to equatorial injections. High‐altitude injections at 15°N produce the largest reduction in global average temperature of 0.2° per Tg S/yr for the last 7 years of a 10 year experiment. Injections at higher altitude are generally more efficient at reducing surface temperature, with the exception of large equatorial injections of at least 12 Tg SO2/yr. These findings have important implications for designing a strategy to counteract global climate change.
Creating Aerosol Types from CHemistry (CATCH): A New Algorithm to Extend the Link Between Remote Sensing and Models
Authors: Dawson K. W. , Meskhidze N. , Burton S. P. , Johnson M. S. , Kacenelenbogen M. S. , Hostetler C. A. , Hu Y.
Published: November 2017

Current remote sensing methods can identify aerosol types within an atmospheric column, presenting an opportunity to incrementally bridge the gap between remote sensing and models. Here a new algorithm was designed for Creating Aerosol Types from CHemistry (CATCH). CATCH‐derived aerosol types—dusty mix, maritime, urban, smoke, and fresh smoke—are based on first‐generation airborne High Spectral Resolution Lidar (HSRL‐1) retrievals during the Ship‐Aircraft Bio‐Optical Research (SABOR) campaign, July/August 2014. CATCH is designed to derive aerosol types from model output of chemical composition. CATCH‐derived aerosol types are determined by multivariate clustering of model‐calculated variables that have been trained using retrievals of aerosol types from HSRL‐1. CATCH‐derived aerosol types (with the exception of smoke) compare well with HSRL‐1 retrievals during SABOR with an average difference in aerosol optical depth (AOD) <0.03. Data analysis shows that episodic free tropospheric transport of smoke is underpredicted by the Goddard Earth Observing System‐ with Chemistry (GEOS‐Chem) model. Spatial distributions of CATCH‐derived aerosol types for the North American model domain during July/August 2014 show that aerosol type‐specific AOD values occurred over representative locations: urban over areas with large population, maritime over oceans, smoke, and fresh smoke over typical biomass burning regions. This study demonstrates that model‐generated information on aerosol chemical composition can be translated into aerosol types analogous to those retrieved from remote sensing methods. In the future, spaceborne HSRL‐1 and CATCH can be used to gain insight into chemical composition of aerosol types, reducing uncertainties in estimates of aerosol radiative forcing.
Radiative and Chemical Response to Interactive Stratospheric Sulfate Aerosols in Fully Coupled CESM1(WACCM)
Authors: Mills Michael J. , Richter Jadwiga H. , Tilmes Simone , Kravitz Ben , MacMartin Douglas G. , Glanville Anne A. , Tribbia Joseph J. , Lamarque Jean‐François , Vitt Francis , Schmidt Anja , Gettelman Andrew , Hannay Cecile , Bacmeister Julio T. , Kinnison Douglas E.
Published: November 2017

We present new insights into the evolution and interactions of stratospheric aerosol using an updated version of the Whole Atmosphere Community Climate Model (WACCM). Improved horizontal resolution, dynamics, and chemistry now produce an internally generated quasi‐biennial oscillation and significant improvements to stratospheric temperatures and ozone compared to observations. We present a validation of WACCM column ozone and climate calculations against observations. The prognostic treatment of stratospheric sulfate aerosols accurately represents the evolution of stratospheric aerosol optical depth and perturbations to solar and longwave radiation following the June 1991 eruption of Mount Pinatubo. We confirm the inclusion of interactive OH chemistry as an important factor in the formation and initial distribution of aerosol following large inputs of sulfur dioxide (SO2) to the stratosphere. We calculate that depletion of OH levels within the dense SO2 cloud in the first weeks following the Pinatubo eruption significantly prolonged the average initial e‐folding decay time for SO2 oxidation to 47 days. Previous observational and model studies showing a 30 day decay time have not accounted for the large (30–55%) losses of SO2 on ash and ice within 7–9 days posteruption and have not correctly accounted for OH depletion. We examine the variability of aerosol evolution in free‐running climate simulations due to meteorology, with comparison to simulations nudged with specified dynamics. We assess calculated impacts of volcanic aerosols on ozone loss with comparisons to observations. The completeness of the chemistry, dynamics, and aerosol microphysics in WACCM qualify it for studies of stratospheric sulfate aerosol geoengineering.
Reply to Comment on “Radiative Transfer in CO2‐Rich Atmospheres: 1. Collisional Line Mixing Implies a Colder Early Mars”
Authors: Ozak N. , Aharonson O. , Halevy I.
Published: November 2017

Turbet and Tran (2017) have identified that we mistakenly used air‐broadened CO2 absorption spectra to generate coefficients for a rapid radiative transfer code, instead of self‐broadened spectra. The resulting underestimation of absorption by CO2 led us to suggest that when the effects of CO2 line mixing are taken into account, surface temperatures on early Mars are up to 15 K colder than those calculated in previous studies, in which empirical corrections of the CO2 spectrum were used (χ factors). Using the correct CO2 absorption spectra, including the effects of line mixing, Turbet and Tran (2017) found that the surface temperature is colder by only 2 K than temperatures calculated with the χ factor approach. While we acknowledge the mistake, and thank Turbet and Tran (2017) for finding and correcting it, we note that our main conclusions hold that surface temperatures are overestimated when empirical χ factors are used instead of a full account of CO2 line mixing in radiative transfer calculations in CO2‐rich planetary atmospheres. Additionally, we emphasize that the rapid radiative transfer model we developed and tested is useful for studies of planetary climate, provided the correct absorption spectra are used to generate new k coefficients.
Linkage Analysis
Authors: Shao Yongzhao
Published: November 2017

Linkage analysis is an important initial step in localizing and identifying genes in the chromosomes that underlie many human diseases and other traits of interest. Frequently, genetic linkage analysis proceeds by comparing the inheritance pattern of the trait and that of the genetic markers to establish linkage between the trait and marker loci where family (or pedigree)‐based study designs are often of great importance. In the past two decades, linkage analysis‐based gene mapping has largely been supplanted by the population‐based genome‐wide association study (GWAS) based on single‐nucleotide polymorphisms (SNPs). The rapid development and increased adoption of next‐generation whole‐genome sequencing (WGS) has revived linkage analysis and family‐based studies for the identification and characterization of functional variants including rare variants. This article provides a brief overview of commonly used methods for linkage analysis, which include model‐free and model‐based methods for mapping qualitative‐ and quantitative‐trait loci. Linkage analysis methods suitable under locus heterogeneity are reviewed. Linkage analysis methods that utilize both IBD allele sharing information and LD information as well as genome‐wide linkage analysis are discussed. Issues on the design of linkage studies are also briefly discussed.
Within‐Case Designs: Distribution‐Free Methods
Authors: Lix Lisa M.
Published: November 2017

In within‐case designs, individuals are measured repeatedly over time or across multiple experimental conditions. Univariate and multivariate parametric procedures for testing within‐case effects may lose statistical power under departures from a multivariate normal distribution. Nonparametric procedures based on rank scores or bootstrapping are useful alternatives for testing within‐case effects when the data are skewed or have heavy tails. We consider these methods when there are missing observations and for complex designs.
Intention‐to‐Treat: Overview
Authors: Lachin John M.
Published: November 2017

The intention‐to‐treat principle developed from concerns that an analysis of a subset of subjects entered into a clinical trial may provide a severely biased estimate of the expected outcome in all subjects for whom a treatment might be administered. Theintention‐to‐treat analysisincludes all data from all subjects randomized into the study to provide a pragmatic assessment of the effects of therapy, regardless of drug tolerability or compliance. This approach is contrasted with an analysis of a subset, such as a “per protocol” analysis that only includes participants that tolerated the assigned agent, who were largely compliant, and who completed follow‐up.

Therefore, a true intention‐to‐treat analysis requires anintention‐to‐treat designin which all those randomized are expected to complete follow‐up assessments to the extent possible, even if no longer taking the drug, and their data should be employed in the analysis.

Many statistical methods can provide an unbiased comparison of treatment effects when all missing observations are ignorable, that is, no bias is introduced. However, this assumption is inherently unverifiable. Thus, the only incontrovertibly unbiased study is one in which all randomized patients are evaluated and included in the analysis, assuming that other features of the study are also unbiased. This design is the essence of the intent‐to‐treat philosophy.
Bivariate Distributions
Authors: Christman Mary C.
Published: November 2017

Bivariate distributions play a special role in environmental science as they are the underpinnings of analyses of relationships between two random variables. These relationships include analyses such as biserial correlation between continuous and discrete random variables, measures of association in an
r
×
c
contingency table, Pearson's product–moment correlation, Kendall's tau, Spearman's rank correlation, and many others. In addition to the studies of the dependency between two variables, interest may center on other analyses; for example, multivariate general (or generalized) linear modeling when two or more response variables are involved. Inferences involving two random variables rely on knowledge of their bivariate distribution. Probably, the best‐known example is estimation and testing of the correlation coefficient in the bivariate normal distribution for two continuous random variables. There are many other distributions of importance as well, especially those relating two discrete random variables or a discrete to a continuous variable. This article describes a few of the more common distributions in environmental practice and, where appropriate, mentions the multivariate distribution of which the bivariate is a special case.
Model‐Assisted Sampling and Estimation
Authors: Fattorini Lorenzo
Published: November 2017

Model‐assisted sampling and estimation is concerned with design‐based inference performed assuming appropriate models to improve precision.
Project Management in Government
Authors: Khamooshi Homayoun
Published: November 2017

Government project management (GPM) environment normally has more uncertainties and complexities associated with it than nongovernment project environment. As such, a more robust and rigorous project management approach is needed for successful delivery of products (deliverable) and benefits. In addition, usually government projects are outsourced rather than delivered and managed in‐house. This implies that GPM is all about governance. When it comes to governance, government project managers need to be deeply involved in the management of these projects. First and foremost, a veryrobust governance structuremust be put in place, making sure that components of the structures are fully functional and engaged in the supervision of the project execution. The second important issue isfront end planning (FEP). It is the government's responsibility to have a deep understanding of the scope of project, the required budget, and the risks associated with the project. The FEP, along with continuous engagement of the governance team over the phases of project, paves the way for successful delivery. Finally, to be successful, the government project managers should focus onfive KPIs(key performance indicators), namely, scope management, quality management, time management, cost management, and risk management. This article addresses these critical success factors and their dynamic relationship in GPM environment.
Hall,PeterG
Authors: Robinson John , Welsh Alan H.
Published: November 2017

Peter Hall was an Australian probabilist and mathematical statistician who, in an incredibly productive career, contributed both widely and deeply to martingale limit theory, rates of convergence in the central limit theorem, extreme value theory, coverage processes, the bootstrap, and, in its widest sense, nonparametric function estimation. In addition to his productivity, he was renowned for his technical skill and intuition in developing and applying mathematical methods to a wide range of problems. He was an active member of the international community and a leading advocate for mathematics and statistics in Australia.
Definitions and Hypotheses of Seed Dormancy
Authors: Hilhorst Henk W.M.
Published: November 2017

The sections in this article are

Introduction

Classifications of Dormancy

Definitions of Dormancy

Primary Dormancy

Secondary Dormancy

Signaling in Dormancy

Challenges for the Future
Genetic Aspects of Seed Dormancy
Authors: Bentsink Leónie , Soppe Wim , Koornneef Maarten
Published: November 2017

The sections in this article are

Introduction

Mutant Approaches inArabidopsis

Mutant Approaches in Other Species

Genetic Analyses of Natural Variation

What Do the Genetics Teach Us about Dormancy and Germination?
Regulation ofABAandGALevels during Seed Development and Germination inArabidopsis
Authors: Yamaguchi Shinjiro , Kamiya Yuji , Nambara Eiji
Published: November 2017

The sections in this article are

Introduction

Biosynthetic and Deactivation Pathways ofABAandGA

Inhibitors ofABAandGAMetabolism: Efficacy and Side Effects of Drugs

Regulation ofABAandGALevels inArabidopsis Seeds

Conclusions and Perspectives
Transcription Factors ofArabidopsisand Rice: A Genomic Perspective
Authors: Riechmann José Luis
Published: November 2017

The sections in this article are

Introduction

Arabidopsisand Rice Genomes: The Angiosperm Complement of Transcription Factors

Plant Promoters
Chromatin Remodeling and Histone Variants in Transcriptional Regulation and in MaintainingDNAMethylation
Authors: Reyes J.C. , Brzeski J. , Jerzmanowski A.
Published: November 2017

The sections in this article are

Introduction

ATP‐Dependent Chromatin Remodeling

Chromatin Remodeling andDNAMethylation

Histone Variants in the Regulation of Chromatin Functions
Perovskite Solar Cells with ZnO Electron‐Transporting Materials
Authors: Zhang Peng , Wu Jiang , Zhang Ting , Wang Yafei , Liu Detao , Chen Hao , Ji Long , Liu Chunhua , Ahmad Waseem , Chen Zhi David , Li Shibin
Published: November 2017

Perovskite solar cells (PSCs) have developed rapidly over the past few years, and the power conversion efficiency of PSCs has exceeded 20%. Such high performance can be attributed to the unique properties of perovskite materials, such as high absorption over the visible range and long diffusion length. Due to the different diffusion lengths of holes and electrons, electron transporting materials (ETMs) used in PSCs play a critical role in PSCs performance. As an alternative to TiO2 ETM, ZnO materials have similar physical properties to TiO2 but with much higher electron mobility. In addition, there are many simple and facile methods to fabricate ZnO nanomaterials with low cost and energy consumption. This review focuses on recent developments in the use of ZnO ETM for PSCs. The fabrication methods of ZnO materials are briefly introduced. The influence of different ZnO ETMs on performance of PSCs is then reviewed. The limitations of ZnO ETM‐based PSCs and some solutions to these challenges are also discussed. The review provides a systematic and comprehensive understanding of the influence of different ZnO ETMs on PSCs performance and potentially motivates further development of PSCs by extending the knowledge of ZnO‐based PSCs to TiO2‐based PSCs.
Two‐Photon Optical Properties in Individual Organic–Inorganic Perovskite Microplates
Authors: Wei Qi , Du Bin , Wu Bo , Guo Jia , Li Ming jie , Fu Jianhui , Zhang Zhipeng , Yu Jianwei , Hou Tianyu , Xing Guichuan , Sum Tze Chien , Huang Wei
Published: November 2017

Metal‐halide perovskites are recently extensively investigated as light absorbing material in solar cells. The outstanding optoelectronic properties and tunable light emission of the perovskites also make them promising candidates for light emitting diodes and lasers. However, understanding the relevant mechanisms and processes of the dependence of perovskite light emission on temperature and crystal size is still challenging. Herein, the CH3NH3PbBr3 monocrystals of different sizes are uniformly excited by two‐photon absorption at 800 nm (100 fs, 1 KHz). In contrast to the reported relative large exciton binding energy (≈76 meV) and spectrum clearly resolved excitonic absorption, the light emission origin in CH3NH3PbBr3 microcrystals at room temperature is unambiguously determined to be dominated by free electron–hole bimolecular recombination. The coherent light emission threshold of CH3NH3PbBr3 microcrystal increases with temperature, which is closely related to the temperature induced transition from exciton gas to free charge carriers. In addition, the coherent light emission threshold is found to decrease with the microcrystal size, which could be well interpreted by the interaction between the optical confinement, defect density, and cavity quantum electrodynamics effect. These results presented here may facilitate the development of perovskite light emitting diodes and lasers.
Aqueous Bismuth Titanium–Oxo Sulfate Cluster Speciation and Crystallization
Authors: Molina Pedro I. , Kozma Karoly , Santala Melissa , Falaise Clément , Nyman May
Published: November 2017

Inorganic aqueous metal–oxo clusters are both functional “molecular metal oxides” and intermediates to understand metal oxide growth from water. There has been a recent surge in discovery of aqueous Ti‐oxo clusters but without extensive solution characterization. We use small‐angle and total X‐ray scattering, dynamic light scattering, transmission electron microscopy, and a single‐crystal X‐ray structure to show that heterometals such as bismuth stabilize labile Ti–oxo sulfate clusters in aqueous solution.[Ti22Bi7O41(OH)(OH2)30(SO4)12]2+ features edge‐sharing between the Ti and Bi polyhedra, in contrast to the dominant corner‐linking of Ti‐oxo clusters. Bi stabilizes the Ti‐polyhedra, which are synergistically stabilized by the bidentate sulfates. Gained stability and potential functionality from heterometals is an incentive to develop more broadly the landscape of heterometallic Ti–oxo clusters.
Temperature‐Mediated Template Release: Facile Growth of Copper(I) Mixed Ethynediide/Isopropylethynide Nanoclusters
Authors: Zhang Leon Li‐Min , Mak Thomas C. W.
Published: November 2017

In the comproportionation reaction of CuIIX2 and Cu0 with isopropylacetylene (iPr−C≡C−H), the ethynediide species C22− is generated via concomitant C−H/C−C bond cleavage of the iPr−C≡C−H precursor under moderate temperature to direct the formation of CuI mixed ethynediide/isopropylethynide nanoclusters (potentially explosive). The active ethynediide dianion C22− exhibits chameleon‐like templating behavior to form C2@Cum (m=6 (3, 4), 7 (2, 4), 8 (1)) central structural units for successive formation of {C22−⊂Cu24} (1, 2), {6 C22−⊂Cu48} (3), and {18 C22−⊂Cu92} (4) complexes. Bearing the highest C22− content, complex 4 features an unprecedented nanoscale Cu2C2 kernel. Furthermore, 1–3 exhibit structure‐controlled photoluminescence in the solid state.
Phosphate ester groups‐containing ricinoleic acid‐based Ca/Zn: Preparation and application as novel thermal stabilizer for PVC
Authors: Wang Mei , Jiang Jianchun , Xia Jianling , Li Shouhai , Li Mei
Published: November 2017

Phosphate ester groups containing ricinoleic acid‐based Ca/Zn (LPPRA‐Ca and LPPRA‐Zn) stabilizer was successfully synthesized from ricinoleic acid (RA) and used as thermal stabilizers for poly(vinyl chloride) (PVC). These thermal stabilizers were characterized by Fourier transform infrared spectrometry, 1H nuclear magnetic resonance, and inductively‐coupled plasma atomic emission spectroscopy. The effects of LPPRA‐Ca/LPPRA‐Zn, CaSt2/ZnSt2, and other stabilizers on the thermal stability of PVC were studied through Congo Red test, discoloration tests, thermogravimetric analysis (TGA), TGA–infrared, and TGA–mass spectrometry. The thermal stability tests show that LPPRA‐Ca/LPPRA‐Zn displays the best initial color stability and long‐term thermal stability for PVC. The superior performance is attributed to the synergistic effect of LPPRA‐Ca and LPPRA‐Zn. Moreover, a lower Zinc content of LPPRA‐Zn in PVC helps to decrease the “zipper dehydrochlorination” of the product, which contributes to a better initial thermal stability. Except for the better stabilization performance, LPPRA‐Ca/LPPRA‐Zn also displays better plasticization performance for PVC compared with other stabilizers. A possible stabilizing mechanism of PVC/LPPRA‐Ca/LPPRA‐Zn system was presented. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45940.
Association Study of Transforming Growth Factor Alpha TaqI Polymorphism and the Risk of Cleft Lip and/or Palate in an Iranian Population
Authors: Bagheri Fahimeh , Ebadifar Asghar , Khorram Khorshid Hamid Reza , Kamali Koorosh
Published: November 2017

Background

The aim of this study is to evaluate the association of TGFA TaqI polymorphism with nonsyndromic cleft lip and/or palate (NSCLP) in an Iranian population.

Methods

In this case–control study, 113 children with NSCLP and 209 controls were included. Genotyping of the TaqI polymorphism was performed by polymerase chain reaction and restriction fragment length polymorphism methods. A p‐value of <0.05 was considered statistically significant.

Results

For the TGFA TaqI polymorphism, the distributions of genotypes in the NSCLP (p = 0.810) and control group (p = 0.422) were in Hardy‐Weinberg equilibrium. There was no statistically significant difference in the genotype distribution (p = 0.059) and allele frequency (p = 0.065) of the TGFA TaqI polymorphism in the NSCLP and control groups.

Conclusion

TGFA TaqI polymorphism was not associated with the risk of NSCLP in Iranian children. Birth Defects Research 109:1386–1389, 2017.© 2017 Wiley Periodicals, Inc.
Hemodynamic guidance of mitral paravalvular leak closure: The V is the key
Authors: Goldstein James A.
Published: November 2017

Key Points

Severe mitral paravalvular leak (PVL) induces elevated mean left atrial (LA) pressure (LAP) and prominent V waves, leading to pulmonary hypertension and right heart failure

PVL closure promptly reduces V wave and mean LAP, correlates with improved echo regurgitation grade, and exerts immediate benefit to the lungs and right heart

Hemodynamic response patterns facilitate PVL closure
Make PCI great again: Come on USA, catch up with the rest of the world
Authors: Heuser Richard
Published: November 2017

Key Points

Same day discharge after PCI lags in the USA

The radial approach to PCI reduces complications compared to the femoral approach

USA physicians need to seize the opportunity to not only perform PCI safely, but with economic responsibility
Simultaneous transcatheter transfemoral aortic and transeptal mitral valve replacement using Edward SAPIEN S3
Authors: Fanari Zaher , Mahmaljy Hadi , Nandish Shalish , Goswami Nilesh J.
Published: November 2017

Patients with concomitant severe aortic stenosis (AS) and severe mitral stenosis (MS) with mitral annular calcification (MAC) constitute an elderly high‐risk population with multiple baseline comorbidities that coexist even before they develop severe valvular dysfunction. Transcatheter mitral valve replacements (TMVR) offer an alternative option for high‐risk patient with severe MS with MAC. A simultaneous transfemoral Transcatheter aortic valve replacement (TAVR) and transseptal TMVR is feasible and offers the least invasive approach of management. We are reporting a case of an 83‐year‐old man with very symptomatic severe AS and severe native MS with associated severe MAC and moderate mitral regurgitation with high STS score who underwent a simultaneous transfemoral TAVR and transseptal TMVR with good results and great improvement in symptoms that was maintained on 10 months follow‐up.
Fatal CTLA‐4 heterozygosity with autoimmunity and recurrent infections: a de novo mutation
Authors: Moraes‐Fontes Maria Francisca , Hsu Amy P. , Caramalho Iris , Martins Catarina , Araújo Ana Carolina , Lourenço Filipa , Taulaigo Anna V. , Lladó Ana , Holland Steven M. , Uzel Gulbu
Published: November 2017

Key Clinical Message

Primary immunodeficiency disorders are rarely diagnosed in adults but must be considered in the differential diagnosis of combined recurrent infections and autoimmune disease. We describe a patient with CTLA‐4 haploinsufficiency and an abnormal regulatory T‐cell phenotype. Unusually, infections were more severe than autoimmunity, illustrating therapeutic challenges in disease course.
Co‐doping Nitrogen/Sulfur through a Solid‐State Reaction to Enhance the Electrochemical Performance of Anatase TiO2 Nanoparticles as a Sodium‐Ion Battery Anode
Authors: Song Wei , Zhao Hanqing , Wang Liqin , Liu Shibin , Li Zhong
Published: November 2017

Nitrogen‐ and/or sulfur‐doping has been used to enhance the electrochemical performance of TiO2 anodes in lithium‐ion batteries. Multiple doping in one step presents a challenge to produce anodes with excellent performance. Herein, we reports a facile process to co‐dope nitrogen and sulfur into black anatase TiO2 nanoparticles accomplished by using a solid‐state reaction with dried TiO2 gel and thiourea. Co‐doping introduced N and S atoms into the TiO2 matrix, increasing oxygen vacancies, thus enhancing the intrinsic electronic conductivity. Co‐doping also decreased the size of TiO2 nanoparticles from 15.6 to 10.1 nm, and increased the surface area from 77 to 129 m2 g−1, facilitating insertion/extraction of Na ions during charge‐discharge cycling. N/S co‐doped TiO2 exhibited a signficantly higher performance as a sodium‐ion battery anode than pristine black TiO2. The rate performance of the co‐doped TiO2 is improved up to 80 % in comparison with pristine black TiO2.
Leaded Bronze: An Innovative Lead Substitute for Cathodic Electrosynthesis
Authors: Gütz Christoph , Grimaudo Valentine , Holtkamp Michael , Hartmer Marius , Werra Janina , Frensemeier Lisa , Kehl Anton , Karst Uwe , Broekmann Peter , Waldvogel Siegfried R.
Published: November 2017

The most common cathode materials for electro‐organic reduction reactions are lead, mercury, and cadmium, as they exhibit a large over‐potential for the hydrogen evolution reaction (HER). Therefore, quite negative potentials can be reached, which are important for many electro‐organic conversions like dehalogenations, deoxygenations, and many more. As a major drawback, all three metals are prone to cathodic corrosion forming highly toxic organometallic compounds, which might contaminate the product. Thus, the synthesis of fine chemicals and biologically active agents through electro‐synthesis is highly challenging. To tackle this issue, we present leaded bronze as an innovative, easily available, and inexpensive cathode material, which combines an excellent performance in electrosynthesis with a significantly increased mechanical and chemical stability. Our results demonstrate that leaded bronze can effectively replace lead as an electrode material in a significant number of transformations.
Design of a Hypersensitive pH‐Sensory System Created by a Combination of Charge Neutralization and Aggregation‐Induced Emission (AIE)
Authors: Yoshihara Daisuke , Noguchi Takao , Roy Bappaditya , Sakamoto Junji , Yamamoto Tatsuhiro , Shinkai Seiji
Published: November 2017

In our bodies, a slight pH change causes remarkable activation or serious damage in the biological processes and continuously keeps biological homeostasis. Detection of such a slight pH change has been a constant demand in searching for unusual biological events. In this paper, we demonstrate a novel pH sensory system that has been achieved through a combination of charge neutralization by a slight pH change with aggregation‐induced emission (AIE). We selected a cyano‐functionalized oligo(phenylene‐vinylene) (cyanoOPV) backbone for AIE and introduced ammonium‐tethered boronic acid groups as a pH‐dependent function. The self‐assembling of these dyes (OPV‐Cn) was readily achieved by pH‐dependent charge neutralization at the neutral pH region. This sensory system showed unusually sensitive pH responsiveness in a narrow pH range. Moreover, this pH change was observed in a biologically important neutral pH region. We therefore believe that this system is broadly applicable to detect the slight pH change occurring in the biological events.
Furans Accessed through Visible‐Light‐Mediated Oxidative [3+2] Cycloaddition of Enols and Alkynes
Authors: Shao Ailong , Luo Xu , Chiang Chien‐Wei , Gao Meng , Lei Aiwen
Published: November 2017

Visible‐light‐mediated formation of furans though direct oxidative [3+2] cycloaddition of 1,3‐diones and alkynes is described. This protocol provides a simple and mild route to poly‐substituted furans in moderate‐to‐good yields. Preliminary mechanistic studies suggest that this reaction likely follows a radical addition/cyclization pathway.
Production of recombinant human tektin 1, 2, and 4 and in vitro assembly of human tektin 1
Authors: Budamagunta M. S. , Guo F. , Sun N. , Shibata B. , FitzGerald P. G. , Voss J. C. , Hess J. F.
Published: November 2017

Proteins predicted to be composed of large stretches of coiled‐coil structure have often proven difficult to crystallize for structural determination. We have successfully applied EPR spectroscopic techniques to the study of the structure and assembly of full‐length human vimentin assembled into native 11 nm filaments, in physiologic solution, circumventing the limitations of crystallizing shorter peptide sequences. Tektins are a small family of highly alpha helical filamentous proteins found in the doublet microtubules of cilia and related structures. Tektins exhibit several similarities to intermediate filaments (IFs): moderate molecular weight, highly alpha helical, hypothesized to be coiled‐coil, and homo‐ and heteromeric assembly into long smooth filaments. In this report, we show the application of IF research methodologies to the study of tektin structure and assembly. To begin in vitro studies, expression constructs for human tektins 1, 2, and 4 were synthesized. Recombinant tektins were produced in E. coli and purified by chromatography. Preparations of tektin 1 successfully formed filaments. The recombinant human tektin 1 was used to produce antibodies which recognized an antigen in mouse testes, most likely present in sperm flagella. Finally, we report the creation of seven mutants to analyze predictions of coiled‐coil structure in the rod 1A domain of tektin 1. Although this region is predicted to be coiled‐coil, our EPR analysis does not reflect the parallel, in register, coiled‐coil structure as demonstrated in vimentin and kinesin. These results document that tektin can be successfully expressed and assembled in vitro, and that SDSL EPR techniques can be used for structural analysis.
Survival of human papillomavirus‐associated cancers: Filling in the gaps
Authors: Osazuwa‐Peters Nosayaba , Massa Sean T. , Simpson Matthew C. , Adjei Boakye Eric , Varvares Mark A.
Published: November 2017

Human papillomavirus‐associated cancers contribute to the total cancer burden in the United States. Although they are mostly preventable, 5‐year relative survival rates can be as low as 47% for penile cancer and as high as 66% for vulvar cancer.

See also pages 203‐11.
Tip‐Enhanced Raman Spectroscopy: A Tool for Nanoscale Chemical and Structural Characterization of Biomolecules
Authors: Bonhommeau Sébastien , Lecomte Sophie
Published: November 2017

Due to its high molecular sensitivity and spatial optical resolution down to sub‐nanometer values, tip‐enhanced Raman spectroscopy (TERS) has emerged as a powerful microscopy technique for nanoscale characterization. Progress in TERS instrumentation and in the manufacturing of efficient TERS tips allow for chemical and structural analysis under various experimental conditions (different wavelengths, substrates, and surrounding media). Many biological species have been examined by using this technique. Nucleic acids (individual nucleobases, DNA, and RNA) can show specific TERS features that reveal their composition, conformation, and defects. TERS studies on peptides and proteins (such as amyloid fibrils) provide relevant information on their morphology and structure, leading to valuable insight to their functions and behavior. Finally, lipid layers and membranes, viruses, bacteria, and cells can also be finely characterized. Generalizing TERS measurements in liq‐ uid medium to study biological systems is the main future challenge.
Buprenorphine in Neonatal Abstinence Syndrome
Authors: Kraft Walter K.
Published: November 2017

Infants exposed in utero to opioids will demonstrate a withdrawal syndrome known as neonatal abstinence syndrome (NAS). Buprenorphine is a long‐acting opioid with therapeutic use in medication‐assisted treatment of opioid dependency in adults and adolescents. Emerging data from clinical trials and treatment cohorts demonstrate the efficacy and safety of sublingual buprenorphine for those infants with NAS who require pharmacologic treatment. Pharmacometric modeling will assist in defining the exposure–response relationships and facilitate dose optimization.
Real‐Life Use of Neurohormonal Antagonists and Loop Diuretics in Chronic Heart Failure: Analysis of Serial Biomarker Measurements and Clinical Outcome
Authors: Brankovic Milos , Akkerhuis K. Martijn , van Boven Nick , Manintveld Olivier , Germans Tjeerd , Brugts Jasper , Caliskan Kadir , Umans Victor , Constantinescu Alina , Kardys Isabella
Published: November 2017

We determined the temporal effects of neurohormonal antagonists and loop diuretics on serially assessed (3‐monthly) cardiorenal biomarkers, functional status, and clinical outcomes in 250 patients with chronic heart failure (CHF) with reduced ejection fraction. In blood, we measured NT‐proBNP, troponin T, C‐reactive protein, creatinine, cystatin C; in urine, N‐acetyl‐beta‐d‐glucosaminidase and kidney‐injury‐molecule‐1. Angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs) were inversely associated with cardiac impairment, inflammation, and renal tubular damage, but not with glomerular dysfunction. Diuretics were associated with worse biomarker profiles and with a hazard ratio for adverse clinical outcome of 1.12 (95% confidence interval: 1.03–1.22) per 40 mg higher doses. ACE‐inhibitors/ARBs were more frequently downtitrated and diuretics more frequently uptitrated in patients who experienced endpoints than in those who did not. In conclusion, a decrease or withholding of ACE‐inhibitors/ARBs solely based on glomerular function is not justified because of the beneficial effects on the heart, inflammation, and renal tubules. Higher and increased diuretic doses mark progression towards endstage CHF.