bluuebunny/crossref_metadata_2025 huggingface dataset:
Studying the Potential Application of Electrospun Polyethylene Terephthalate/Graphene Oxide Nanofibers as Electroconductive Cardiac Patch
Authors: Ghasemi Azin , Imani Rana , Yousefzadeh Maryam , Bonakdar Shahin , Solouk Atefeh , Fakhrzadeh Hossein
Published: July 2019

Nowadays, engineering‐based cardiac patches aim to accelerate cardiac regeneration in myocardial infarcted tissues. Considering the fundamental role of cardiac electrophysiology in myocardial function, this study aims to investigate graphene oxide (GO) incorporation in the polyethylene terephthalate (PET) nanofibrous scaffold, as a conductive cardiac patch. The PET/GO nanocomposites are prepared using the uniaxial nozzle and coaxial nozzle electrospinning processes and comprehensively evaluated. The morphological observation indicates a uniform beaded free morphology with an average diameter of 147 ± 38 and 253 ± 67 nm for solid and core–shell nanocomposite fibers, respectively. Addition of GO to the PET nanofibers in a concentration of 0.05 wt% remarkably increases the Young modulus of mats from 30 ± 0.03 to 60 ± 0.02 and 69 ± 0.08 MPa for solid and core–shell nanofibers, respectively. Also, the electroconductivity is improved from 0.7 × 10−6 to 1.175 × 10−6 and 1.3 × 10−6 S cm−1 for solid and core–shell nanofibers, which are in the range of cardiac electroactivity values. PET/GO substrate interestingly supports human umbilical vein endothelial cells’ spreading morphology and cardiomyocyte elongated morphology, mainly where the GO nanosheets are distributed near the surface of nanofibers. In conclusion, the core–shell electrospun PET/GO nanocomposite fibers are suggested as a potential electroactive cardiac patch to improve cardiac cell attachment and proliferation.
Preparation of Polyetheramine‐Grafted Lignin and Its Application in UV‐Resistant Polyurea Coatings
Authors: Fang Chang , Liu Weifeng , Qiu Xueqing
Published: July 2019

Lignin‐containing polyurea coating with good ultraviolet (UV) resistance is prepared by partially substituting polyetheramine with enzymatic hydrolysis lignin. Lignin is first grafted by polyetheramine chains via Mannich reaction, which improves its interfacial compatibility with polyurea matrix. The influences of the modified lignin on the chemical and corrosion resistance, UV‐aging property, and thermal stability of the polyurea coatings are studied. It is demonstrated that lignin‐containing polyurea coatings exhibit excellent UV‐aging properties. Aminating lignin with polyetheramine improves its dispersion in the polymer matrix. This work offers a novel method for the high‐value utilization of biomass lignin in anti‐UV polyurea coatings.
“Missing mutations” in MPS I: Identification of two novel copy number variations by an IDUA‐specific in house MLPA assay
Authors: Jahic Amir , Günther Sven , Muschol Nicole , Fossøy Stadheim Barbro , Braaten Øivind , Kjensli Hyldebrandt Hanne , Kuiper Gé‐Ann , Tylee Karen , Wijburg Frits A. , Beetz Christian
Published: July 2019

Background

Mucopolysaccharidosis type I (MPS I) is a rare, recessively inherited lysosomal storage disorder, characterized by progressive multi‐systemic disease. It is caused by a reduced or absent alpha‐l iduronidase (IDUA) enzyme activity secondary to biallelic loss‐of‐function variants in the IDUA. Over 200 causative variants in IDUA have been identified. Nevertheless, there is a fraction of MPS I patients with only a single mutated IDUA allele detectable.

Methods

As genetic testing of MPS I is usually based on sequencing methods, copy number variations (CNVs) in IDUA can be missed and therefore presumably remain underdiagnosed. The aim of this study was the detection of CNVs using an IDUA‐specific in house multiplex ligation‐dependent probe amplification (MLPA) assay.

Results

A total of five unrelated MPS I patient samples were re‐analyzed after only a single heterozygous IDUA mutation c.979G>C (p.A327P), c.1469T>C (p.L490P), c.1598C>G (p.P533R), c.1205G>A (p.W402X), c.973‐7C>G (p.?) could be identified. We detected a novel splice site variant c.973‐7C>G (p.?), as well as two novel CNVs, a large deletion of IDUA exon 14 and 3’UTR c.(1828 + 1_1829‐1)_(*1963_?)del, and a large duplication extending from IDUA exon 2 to intron 12 c.(157 + 1_158‐1)_(1727 + 1_1728‐1)dup.

Conclusion

Together with the CNVs we previously identified, a total of four pathogenic IDUA CNVs have now been reported.
Relationships between SNPs and prognosis of breast cancer and pathogenic mechanism
Authors: He Yaning , Liu Hui , Chen Qi , Shao Yingbo , Luo Suxia
Published: July 2019

Background

Association between several single‐nucleotide polymorphisms (SNPs) and breast cancer risk has been identified through genome‐wide association studies (GWAS), but little is known about their significance in patients’ prognosis. We screened SNPs which were related to the prognosis of breast cancer in Henan Han population, analyzed relevant genes by bioinformatics in database, and further constructed the genetic regulatory network involved in the pathogenesis of breast cancer.

Methods

We evaluated five SNPs in 232 cases of breast cancer at the Affiliated Tumor Hospital of Zhengzhou University. Relationships between five SNPs, clinical prognostic indicators, and disease‐free survival (DFS) were evaluated by Kaplan–Meier analysis and Cox proportional hazards model. Gene ontology (GO) functional annotation and Kyoto Encyclopedia of genes and Genome (KEGG) analysis were carried out to preliminarily establish genetic regulation network model of breast cancer. Bayesian algorithm was used to optimize the model.

Results

The multivariate Cox proportional hazards model confirmed that SNP rs3803662 (TOX3/TNRC9) had correlation with DFS independently. In the multivariate Cox proportional hazards model, compared with GA/AA, GG increased the recurrent risk of breast cancer (p = .021, hazard ratio [HR] = 2.914). GO analysis showed that the function of TOX3/TNRC9 included biological_process, molecular_function, and cellular_component. According to KEGG signaling pathway database, the map of breast cancer‐related gene regulatory network was obtained. IGF‐IGF1R‐PI3K‐Akt‐mTOR‐S6K was the best possible pathway for the differentiation of breast cancer cells in this network and ER‐TOX3/TNRC9 was the best possible pathway for the survival of tumor cells in this network by Bayesian theorem optimization.

Conclusions

SNP rs3803662 (TOX3/TNRC9) is an independent prognostic factor for breast cancer in Henan Han Population. ER‐TOX3/TNRC9 is the best possible pathway involved in the pathogenesis of breast cancer.
Whole‐exome sequencing and immunohistochemistry findings in von Hippel–Lindau disease
Authors: Guo Xiaopeng , Gao Lu , Hong Xiafei , Guo Dan , Di Wenyu , Wang Xiaoman , Xu Zhiqin , Xing Bing
Published: July 2019

Background

von Hippel–Lindau (VHL) disease has a hereditary, autosomal dominant pattern, and multiple tumors can develop in multiple organs of a single patient. However, the exact mechanisms of tumorigenesis are unclear, and further studies are needed to clarify whether the same signaling pathways are involved in different VHL‐related tumors.

Methods

Whole‐exome sequencing (WES) of tumor and paired peripheral blood samples were performed for a VHL disease pedigree. A bioinformatics analysis was conducted to identify candidate somatic single‐nucleotide variants (SNVs) present in all tumor tissues. Sanger sequencing was then used to validate the SNVs identified using WES. Immunohistochemistry was performed to analyze components of the mTOR pathway, which was abnormally activated in tumor tissues.

Results

Two hemangioblastomas and two renal cell carcinomas were sequenced. The bioinformatics analysis revealed a VHL somatic variant in all tumors; no other SNV was detected. Immunohistochemistry showed the abnormal expression of the phospho‐S6 ribosomal protein in the hemangioblastomas, but not in the renal clear cell carcinomas.

Conclusion

Except for a SNV in the VHL gene, no other somatic SNVs were detected using WES. The phospho‐S6 ribosomal protein in the mTOR pathway is a potential target in VHL‐related cerebellum hemangioblastomas.
Propeller flap donor site closure by means of another propeller flap: A case report and literature review
Authors: Scaglioni Mario F. , Franchi Alberto , Fritsche Elmar
Published: July 2019

Despite some ongoing criticisms, propeller flaps are still gaining popularity among plastic surgeons. The need of skin grafting of the donor site is one of those limitations that sometime affect the beauty and the efficacy of this reconstructive technique. Similar to a classic bi‐lobed skin flap in which the second lobe of the same flap is mobilized to cover the donor site defect of the first lobe, a second, discrete propeller flap can be harvested adjacent to the first, in order to close the first donor site defect, thus avoiding the need for a skin graft. We applied this concept of “sequential” propeller flaps to cover a 4.5 × 4 cm full thickness soft tissue defect at the level of the heel in a 54‐year‐old patient who underwent melanoma excision and sentinel node biopsy.The first and second propeller flaps of 10 × 4.5 cm respectively were rotated on a distal and on a more proximal perforator of the posterior tibial artery (PTA) respectively, obtaining a tension free closure along the entire wound. The post‐operative course was uneventful and the patient returned to full normal activities after 4 weeks. Follow up at 6 months showed a stable reconstruction with no functional deficit. This option, that relies on two separate perforator propeller flaps performed in sequence to obtain complete wound closure, may be kept in mind when dealing with soft tissue defects eligible for propeller flap reconstruction, as long as sizeable perforators in a favorable position are available. Moreover, a brief literature review on propeller flap use in flap donor site closure is also provided.
Grating lobe suppression using grid cover structures on horn arrays with linear and circular polarizations
Authors: Ordek Sezgin , Yamac Yunus E. , Kizilay Ahmet
Published: July 2019

In this letter, a 2 × 2 pyramidal horn antenna array is presented to accomplish linear and circular polarizations with suppressed grating lobes using removable grid cover structures (GCSs) mounted on the top of the antenna array. The spacing between the unit cells becomes farther than a wavelength due to electrically large pyramidal horns and the feeding network. The proposed GCSs, called linear and circular GCS, in this arrangement act as a spacing reducer between the apertures of the horn antennas without the need of physical change of the spacings. Thereby, the desired array factor with newly created apertures can be realized. Although using both GCSs benefit to suppress the highest‐level grating lobe, the circular GCS also converts the polarization to circular. The feeding network, which also prevents a formal array factor due to its massive structure, is made up of equal power dividers with T‐junction waveguides. The proposed horn arrays, the feeding network, and both GCSs are fabricated, and the total antenna is measured to validate the simulation results. A good agreement is achieved between simulations and measurements.
Automatic large quantity landmark pairs detection in 4DCT lung images
Authors: Fu Yabo , Wu Xue , Thomas Allan M. , Li Harold H. , Yang Deshan
Published: July 2019

Purpose

To automatically and precisely detect a large quantity of landmark pairs between two lung computed tomography (CT) images to support evaluation of deformable image registration (DIR). We expect that the generated landmark pairs will significantly augment the current lung CT benchmark datasets in both quantity and positional accuracy.

Methods

A large number of landmark pairs were detected within the lung between the end‐exhalation (EE) and end‐inhalation (EI) phases of the lung four‐dimensional computed tomography (4DCT) datasets. Thousands of landmarks were detected by applying the Harris‐Stephens corner detection algorithm on the probability maps of the lung vasculature tree. A parametric image registration method (pTVreg) was used to establish initial landmark correspondence by registering the images at EE and EI phases. A multi‐stream pseudo‐siamese (MSPS) network was then developed to further improve the landmark pair positional accuracy by directly predicting three‐dimensional (3D) shifts to optimally align the landmarks in EE to their counterparts in EI. Positional accuracies of the detected landmark pairs were evaluated using both digital phantoms and publicly available landmark pairs.

Results

Dense sets of landmark pairs were detected for 10 4DCT lung datasets, with an average of 1886 landmark pairs per case. The mean and standard deviation of target registration error (TRE) were 0.47 ± 0.45 mm with 98% of landmark pairs having a TRE smaller than 2 mm for 10 digital phantom cases. Tests using 300 manually labeled landmark pairs in 10 lung 4DCT benchmark datasets (DIRLAB) produced TRE results of 0.73 ± 0.53 mm with 97% of landmark pairs having a TRE smaller than 2 mm.

Conclusion

A new method was developed to automatically and precisely detect a large quantity of landmark pairs between lung CT image pairs. The detected landmark pairs could be used as benchmark datasets for more accurate and informative quantitative evaluation of DIR algorithms.
Investigation of the influence of B0 drift on the performance of the PLANET method and an algorithm for drift correction
Authors: Shcherbakova Yulia , van den Berg Cornelis A.T. , Moonen Chrit T.W. , Bartels Lambertus W.
Published: July 2019

Purpose

The PLANET method was designed to simultaneously reconstruct maps of T1 and T2, the off‐resonance, the RF phase, and the banding free signal magnitude. The method requires a stationary B0 field over the course of a phase‐cycled balanced SSFP acquisition. In this work we investigated the influence of B0 drift on the performance of the PLANET method for single‐component and two‐component signal models, and we propose a strategy for drift correction.

Methods

The complex phase‐cycled balanced SSFP signal was modeled with and without frequency drift. The behavior of the signal influenced by drift was mathematically interpreted as a sum of drift‐dependent displacement of the data points along an ellipse and drift‐dependent rotation around the origin. The influence of drift on parameter estimates was investigated experimentally on a phantom and on the brain of healthy volunteers and was verified by numerical simulations. A drift correction algorithm was proposed and tested on a phantom and in vivo.

Results

Drift can be assumed to be linear over the typical duration of a PLANET acquisition. In a phantom (a single‐component signal model), drift induced errors of 4% and 8% in the estimated T1 and T2 values. In the brain, where multiple components are present, drift only had a minor effect. For both single‐component and two‐component signal models, drift‐induced errors were successfully corrected by applying the proposed drift correction algorithm.

Conclusion

We have demonstrated theoretically and experimentally the sensitivity of the PLANET method to B0 drift and have proposed a drift correction method.
Spatially regularized estimation of the tissue homogeneity model parameters in DCE‐MRI using proximal minimization
Authors: Bartoš Michal , Rajmic Pavel , Šorel Michal , Mangová Marie , Keunen Olivier , Jiřík Radovan
Published: July 2019

Purpose

The Tofts and the extended Tofts models are the pharmacokinetic models commonly used in dynamic contrast‐enhanced MRI (DCE‐MRI) perfusion analysis, although they do not provide two important biological markers, namely, the plasma flow and the permeability‐surface area product. Estimates of such markers are possible using advanced pharmacokinetic models describing the vascular distribution phase, such as the tissue homogeneity model. However, the disadvantage of the advanced models lies in biased and uncertain estimates, especially when the estimates are computed voxelwise. The goal of this work is to improve the reliability of the estimates by including information from neighboring voxels.

Theory and Methods

Information from the neighboring voxels is incorporated in the estimation process through spatial regularization in the form of total variation. The spatial regularization is applied on five maps of perfusion parameters estimated using the tissue homogeneity model. Since the total variation is not differentiable, two proximal techniques of convex optimization are used to solve the problem numerically.

Results

The proposed algorithm helps to reduce noise in the estimated perfusion‐parameter maps together with improving accuracy of the estimates. These conclusions are proved using a numerical phantom. In addition, experiments on real data show improved spatial consistency and readability of perfusion maps without considerable lowering of the quality of fit.

Conclusion

The reliability of the DCE‐MRI perfusion analysis using the tissue homogeneity model can be improved by employing spatial regularization. The proposed utilization of modern optimization techniques implies only slightly higher computational costs compared to the standard approach without spatial regularization.
Understanding the physical relations governing the noise navigator
Authors: Navest R. J. M. , Mandija S. , Andreychenko A. , Raaijmakers A. J. E. , Lagendijk J. J. W. , van den Berg C. A. T.
Published: July 2019

Purpose

The noise navigator is a passive way to detect physiological motion occurring in a patient through thermal noise modulations measured by standard clinical radiofrequency receive coils. The aim is to gain a deeper understanding of the potential and applications of physiologically induced thermal noise modulations.

Methods

Numerical electromagnetic simulations and MR measurements were performed to investigate the relative contribution of tissue displacement versus modulation of the dielectric lung properties over the respiratory cycle, the impact of coil diameter and position with respect to the body. Furthermore, the spatial motion sensitivity of specific noise covariance matrix elements of a receive array was investigated.

Results

The influence of dielectric lung property variations on the noise variance is negligible compared to tissue displacement. Coil size affected the thermal noise variance modulation, but the location of the coil with respect to the body had a larger impact. The modulation depth of a 15 cm diameter stationary coil approximately 3 cm away from the chest (i.e. radiotherapy setup) was 39.7% compared to 4.2% for a coil of the same size on the chest, moving along with respiratory motion. A combination of particular noise covariance matrix elements creates a specific spatial sensitivity for motion.

Conclusions

The insight gained on the physical relations governing the noise navigator will allow for optimized use and development of new applications. An optimized combination of elements from the noise covariance matrix offer new ways of performing, e.g. motion tracking.
Nonsingular systems of generalized Sylvester equations: An algorithmic approach
Authors: De Terán Fernando , Iannazzo Bruno , Poloni Federico , Robol Leonardo
Published: July 2019

We consider the uniqueness of solution (i.e., nonsingularity) of systems of r generalized Sylvester and ⋆‐Sylvester equations with n×n coefficients. After several reductions, we show that it is sufficient to analyze periodic systems having, at most, one generalized ⋆‐Sylvester equation. We provide characterizations for the nonsingularity in terms of spectral properties of either matrix pencils or formal matrix products, both constructed from the coefficients of the system. The proposed approach uses the periodic Schur decomposition and leads to a backward stable O(n3r) algorithm for computing the (unique) solution.
Stabilization of Pancake Bonding in (TCNQ)2.− Dimers in the Radical‐Anionic Salt (N−CH3−2‐NH2−5Cl−Py)(TCNQ)(CH3CN) Solvate and Antiferromagnetism Induction
Authors: Starodub Tetiana N. , Čižmár Erik , Kliuikov Andrii , Starodub Vladimir A. , Feher Alexander , Kozlowska Mariana
Published: July 2019

We report a new antiferromagnetic radical‐anion salt (RAS) formed from 7,7,8,8‐tetracyanquinonedimethane (TCNQ) anion and 2‐amino‐5‐chloro‐pyridine cation with the composition of (N−CH3−2‐NH2−5Cl−Py)(TCNQ)(CH3CN). The crystallographic data indicates the formation of (TCNQ)2.− radical‐anion π‐dimers in the synthesized RAS. Unrestricted density functional theory calculations show that the formed π‐dimers characterize with strong π‐stacking “pancake” interactions, resulting in high electronic coupling, enabling efficient charge transfer properties, but π‐dimers cannot be stable in the isolated conditions as a result of strong Coulomb repulsions. In a crystal, where (TCNQ)2.− π‐dimers bound in the endless chainlets via supramolecular bonds with (N−CH3−2‐NH2−5‐Cl−Py)+ cations, the repulsion forces are screened, allowing for specific parallel π‐stacking interactions and stable radical‐anion dimers formation. Measurements of magnetic susceptibility and magnetization confirm antiferromagnetic properties of RAS, what is in line with the higher stability of ground singlet state of the radical‐anion pair, calculated by means of the DFT. Therefore, the reported radical‐anion (N−CH3−2‐NH2−5Cl−Py)(TCNQ)(CH3CN) solvate has promising applications in novel magnetics with supramolecular structures.
Versatile Method for the Simultaneous Synthesis of Two Ionic Liquids, Otherwise Difficult to Obtain, with High Atom Economy
Authors: Szpecht Andrea , Zajac Adrian , Zielinski Dawid , Maciejewski Hieronim , Smiglak Marcin
Published: July 2019

A new synthetic approach and full spectral (NMR, IR, MS) and ion chromatographic characterization (IC) of nitrogen‐based ionic liquids bearing allyl‐ or ethyl‐ substituent and triflate, tosylate, methyl sulfate or methanesulfonate anion has been presented. On a sample of 16 new ionic liquids, the versatility of the anion exchange method has been proven. In the metathesis reactions that have been carried out, the halide anion was exchanged in ionic liquid with an alkyl sulfonate based anion using alkylating agents. The results obtained using ion chromatographic analysis on the newly synthesized compounds have been discussed. Also, the utilization of a gaseous methyl halide by‐product, obtained in the metathesis reaction and otherwise difficult to synthesize, has been presented. This approach ensured high atom economy of the overall process, which makes the proposed methodology sustainable and eco‐friendly.
A composite polyaniline/graphene–coated polyamide6 nanofiber mat for electrochemical applications
Authors: Tambakoozadeh Nooshin , Youssefi Mostafa , Semnani Dariush
Published: July 2019

In this study, polyamide6 (PA6) nanofiber mats were fabricated through the electrospinning process. The nanofibers were coated by polyaniline (PANI) using the in situ polymerization of aniline in the presence of graphene oxide. The composite of the PANI/graphene oxide–coated nanofiber mat was treated with hydrazine monohydrate to reduce graphene oxide to graphene, and this was followed by the reoxidation of PANI. Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), wide angle X‐ray diffraction (WAXD), thermal gravimetric analysis (TGA), tensile strength tests, electrical conductivity measurements, cyclic voltammetry (CV), and charge/discharge measurements were conducted on the composite PA6/graphene nanofiber mats. It was found that the surface of the PA6 nanofibers was coated uniformly with the granular PANI and graphene oxide. Besides, the composite nanofibers showed good tensile and thermal properties. Their electrical conductivity and specific capacitance, when used as a separator in the cell, were 1.02 × 10−4 S/cm and 423.28 F/g, respectively. Therefore, the composite PANI/reduced graphene oxide–coated PA6 nanofiber mats could be regarded as suitable candidates for application in energy storage devices.
Deformation characteristics of glass‐filled epoxy composite under compression: Role of filler shape and volume fraction
Authors: Singh Sarthak S. , Chakraborty Pritam , Kitey Rajesh
Published: July 2019

The influence of filler shape on the compression behavior of low‐volume fraction glass‐filled epoxy composite is studied. Test materials are prepared by embedding two filler variants, spherical and slender, up to 10% volume fraction into the matrix. Although the slender fillers improve the yield and strain hardening characteristics of epoxy, the effect of spherical ones is observed only on the latter. The trends remain the same but magnifies when the filler content is increased. Optical analyses of deforming specimens reveal extensive presence of shear bands. The crushed sample micrographs show broken fillers and severe matrix cracking, indicating significant resistance to deformation provided by the slender fillers, whereas the debonded spherical particles appear to have lesser impact on the deformation characteristics. Finite strain elasto‐plastic finite element analyses on representative volume elements complement experimental observations. Simulations clearly indicate that the deformation in slender filler composites are filler dominated. On the contrary, due to large inter particle spacing, the matrix governs the deformation response in spherical particle composites. Interestingly, in any case, the inclusion shape has no effect on the average matrix stress.
Enrichment and analysis of quaternary alkaloids from Zanthoxylum simulans using weak cation exchange solid‐phase extraction coupled with LC–MS
Authors: Fan Minxia , Tian Yongqiang , Chen Guilin , Sarker Satyajit D. , Nahar Lutfun , Wu Jianlin , Li Na , Guo Mingquan
Published: July 2019

Introduction

Quaternary alkaloids (QAs) are the major alkaloids in several traditional Chinese medicines, especially in Zanthoxylum simulans. However, few studies on enrichment of QAs from Z. simulans were conducted due to their high polarity and low content.

Objective

To develop a weak cation exchange (WCX) solid‐phase extraction (SPE) coupled with liquid chromatography mass spectrometry (LC–MS) method to enrich and identify QAs from Z. simulans. Meanwhile, the qualitative and quantitative analyses of QAs were carried out based on the optimum conditions of the method.

Methods

Fresh stem bark of Z. simulans was extracted with 70% aqueous methanol and enriched by WCX‐SPE. A high‐performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS) with an electrospray ionisation (ESI) source was used for the qualitative and quantitative analyses of QAs.

Results

Significant improvements were observed in resolution and abundance of the peaks with WCX‐SPE. The linearity, limit of detection (LOD) and limit of quantification (LOQ) were determined for this analytical method. The linear relationship (A = 338.85C – 187.72, R2 = 0.99) was explored in the range of 0.5 to 312.5 μg/mL for chelerythrine. The LOD and LOQ for chelerythrine standard solutions were 0.0539 μg/mL and 0.1798 μg/mL, respectively. In addition, 22 peaks were detected successfully with WCX‐SPE and nine of them are undetectable without the processing of WCX‐SPE.

Conclusion

A highly selective and efficient method for simultaneous enrichment and identification of QAs from crude extract of Z. simulans was developed for the first time by combining WCX‐SPE with LC–MS.
Quantification of the Dynamic Phosphorylation Process of ERK Using Stable Isotope Dilution Selective Reaction Monitoring Mass Spectrometry
Authors: Lee Nayoung , Lee Joon Won , Kang Gum‐Yong , Park Sang‐Hyun , Kim Kwang Pyo
Published: July 2019

Mitogen‐activated protein (MAP) kinase signaling is critical for various cellular responses, including cell proliferation, differentiation, and cell death. The MAP kinase cascade is conserved in the eukaryotic kingdom as a three‐tiered kinase module—MAP kinase kinase kinase, MAP kinase kinase, and MAP kinase—that transduces signals via sequential phosphorylation upon stimulation. Dual phosphorylation of MAP kinase on the conserved threonine‐glutamic acid‐tyrosine (TEY) motif is essential for its catalytic activity and signal activation; however, the molecular mechanism by which the two residues are phosphorylated remains elusive. In the present study, the pattern of dual phosphorylation of extracellular signal‐regulated kinase (ERK) is profiled on the TEY motif using stable isotope dilution (SID)‐selective reaction monitoring (SRM) mass spectrometry (MS) to elucidate the order and magnitude of endogenous ERK phosphorylation in cellular model systems. The SID‐SRM‐MS analysis of phosphopeptides demonstrates that tyrosine phosphorylation in the TEY motif is dynamic, while threonine phosphorylation is static. Analyses of the mono‐phosphorylatable mutants ERKT202Aand ERKY204Findicate that phosphorylation of tyrosine is not affected by the phosphorylation state of threonine, while threonine phosphorylation depends on tyrosine phosphorylation. The data suggest that dual phosphorylation of ERK is a highly ordered and restricted mechanism determined by tyrosine phosphorylation.
Eco‐efficiency as a strategy for optimizing the sustainability of pest management
Authors: Magarey Roger D , Klammer Sarah SH , Chappell Thomas M , Trexler Christina M , Pallipparambil Godshen R , Hain Ernie F
Published: July 2019

Agricultural industrialization and the subsequent reliance on pesticides has resulted in numerous unintended consequences, such as impacts upon the environment and by extension human health. Eco‐efficiency is a strategy for sustainably increasing production, while simultaneously decreasing these externalities on ecological systems. Eco‐efficiency is defined as the ratio of production to environmental impacts. It has been widely adopted to improve chemical production, but we investigate the challenges of applying eco‐efficiency to pesticide use. Eco‐efficiency strategies include technological innovation, investment in research and development, improvement of business processes, and accounting for market forces. These components are often part of integrated pest management (IPM) systems that include alternatives to pesticides, but its implementation is often thwarted by commercial realities and technical challenges. We propose the creation and adoption of an eco‐efficiency index for pesticide use so that the broad benefits of eco‐efficient strategies such as IPM can be more readily quantified. We propose an index based upon the ratio of crop yield to a risk quotient (RQ) calculated from pesticide toxicity. Eco‐efficiency is an operational basis for optimizing pest management for sustainability. It naturally favors adoption of IPM and should be considered by regulators, researchers, and practitioners involved in pest management. © 2019 Society of Chemical Industry
Thermally induced cyclization of L‐isoleucyl‐L‐alanine in solid state: Effect of dipeptide structure on reaction temperature and self‐assembly
Authors: Ziganshin Marat A. , Larionov Radik A. , Gerasimov Alexander V. , Ziganshina Sufia A. , Klimovitskii Alexander E. , Khayarov Khasan R. , Mukhametzyanov Timur A. , Gorbatchuk Valery V.
Published: July 2019

Thermal treatment of short‐chain oligopeptides is able to initiate the process of their self‐assembly with the formation of organic nanostructures with unique properties. On the other hand, heating can lead to a chemical reaction with the formation of new substances with specific properties and ability to form structures with different morphology. Therefore, in order to have a desired process, researcher needs to find its temperature range. In the present work, cyclization of L‐isoleucyl‐L‐alanine dipeptide in the solid state upon heating was studied. Kinetic parameters of this reaction were estimated within the approaches of the nonisothermal kinetics. The correlation between side chain structure of dipeptides and temperature of their cyclization in the solid state was found for the first time. This correlation may be used to predict the temperature, at which dipeptide self‐assembly changes to chemical reaction. The differences in self‐assembly of linear and cyclic dipeptides were demonstrated using atomic force microscopy. The effect of dipeptide concentration in a source solution and an organic solvent used on self‐assembly of dipeptides was shown. The new information obtained on the thermal properties and self‐assembly of linear and cyclic forms of L‐isoleucyl‐L‐alanine may be useful for the design of new nanomaterials based on oligopeptides, as well as for the synthesis of cyclic oligopeptides.
Effect of Growth Pressure on PLD‐Deposited Gallium Oxide Thin Films for Deep‐UV Photodetectors
Authors: Blumenschein Nicholas , Paskova Tania , Muth John F.
Published: July 2019

Pulsed laser deposition (PLD) is used to grow ‐oriented single‐crystalline β‐gallium oxide (β‐Ga2O3) thin films on c‐plane sapphire substrates by optimized growth temperature and pressure. The morphology and crystallinity of the thin films are examined using X‐ray diffraction and atomic force microscopy. The thin films are used as the semiconductor layer for metal–semiconductor–metal (MSM) photodetector (PD) devices with various electrode designs. The ultraviolet photodetectors are characterized under 250 nm illumination, showing a high current amplitude increase over dark current conditions that approaches three orders of magnitude at a 6 V bias for an optimized growth pressure of 1 × 10−3 torr. The photodetectors' transient response is also measured, allowing for the defect analysis to be performed. A peak spectral responsivity of 30.45 A W−1 is measured at 250 nm incident illumination.
Modeling and detecting change in temporal networks via the degree corrected stochastic block model
Authors: Wilson James D. , Stevens Nathaniel T. , Woodall William H.
Published: July 2019

In many applications, it is of interest to identify anomalous behavior within a dynamic interacting system. Such anomalous interactions are reflected by structural changes in the network representation of the system. We propose and investigate the use of the degree corrected stochastic block model (DCSBM) to model and monitor dynamic networks that undergo a significant structural change. We apply statistical process monitoring techniques to the estimated parameters of the DCSBM to identify significant structural changes in the network. We apply our surveillance strategy to a dynamic US Senate covoting network. We detect significant changes in the political network that reflect both times of cohesion and times of polarization among Republican and Democratic party members. Our analysis demonstrates that the DCSBM monitoring procedure effectively detects local and global structural changes in complex networks, providing useful insights into the modeled system. The DCSBM approach is an example of a general framework that combines parametric random graph models and statistical process monitoring techniques for network surveillance.
Substitutional doping of symmetrical small fullerene dimers
Authors: Kaur Sandeep , Sharma Amrish , Sharma Hitesh , Dhiman Shobhna , Mudahar Isha
Published: July 2019

Magnetic carbon nano‐structures have potential applications in the field of spintronics as they exhibit valuable magnetic properties. Symmetrically sized small fullerene dimers are substitutional doped with nitrogen (electron rich) and boron (electron deficient) atoms to visualize the effect on their magnetic properties. Interaction energies suggests that the resultant dimer structures are energetically favorable and hence can be formed experimentally. There is significant change in the total magnetic moment of dimers of the order of 0.5 μB after the substitution of C atoms with N and B, which can also be seen in the change of density of states. The HOMO‐LUMO gaps of spin up and spin down electronic states have finite energy difference which confirm their magnetic behaviour, whereas for non‐magnetic doped dimers, the HOMO‐LUMO gaps for spin up and down states are degenerate. The optical properties show that the dimers behave as optical semiconductors and are useful in optoelectronic devices. The induced magnetism in these dimers makes them fascinating nanocarbon magnetic materials.
Active pulmonary tuberculosis presenting with acute respiratory failure
Authors: Kilaru Satish Chandra , Prasad Sudhir , Kilaru Hemanth , Anneela Raghavender Reddy , Hasan Ashfaq , Nandury Eshwar Chandra
Published: July 2019

Four patients with active pulmonary tuberculosis (PTB) presenting with respiratory failure are reported here. Bronchogenic PTB, simulating an acute febrile illness or diffuse interstitial lung disease with short duration of symptoms, as a cause of acute respiratory failure is less recognized. If diagnosed and treated early, it has good prognosis. Three of the four patients presented here had an acute presentation with fever, dyspnoea, and hypoxemia with diffuse infiltrative lesions on radiography, and the other younger patient presented predominantly with lobar consolidation. These patients presenting with respiratory failure required intensive care management, and a diagnosis was made with bronchoalveolar lavage fluid and transbronchial lung biopsy. All four patients promptly received antitubercular therapy, showed clinicoradiological improvement, and were stable at 1 year follow up.
Reconciling randomized trial evidence on proximal versus distal outcomes, with application to trials of influenza vaccination for healthcare workers
Authors: Gustafson Reka , Gustafson Paul , Daly Patricia
Published: July 2019

When synthesizing the body of evidence concerning a clinical intervention, impacts on both proximal and distal outcome variables may be relevant. Assessments will be more defensible if results concerning a proximal outcome align with those concerning a corresponding distal outcome. We present a method to assess the coherence of empirical clinical trial results with biologic and mathematical first principles in situations where the intervention can only plausibly impact the distal outcome indirectly via the proximal outcome. The method comprises a probabilistic sensitivity analysis, where plausible ranges for key parameters are specified, resulting in a constellation of plausible pairs of estimated intervention effects, for the proximal and distal outcomes, respectively. Both outcome misclassification and sampling variability are reflected in the method. We apply our methodology in the context of cluster randomized trials to evaluate the impacts of vaccinating healthcare workers on the health of elderly patients, where the proximal outcome is suspected influenza and the distal outcome is death. However, there is scope to apply the method for other interventions in other disease areas.
13.26% Efficiency Polymer Solar Cells by Optimizing Photogenerated Exciton Distribution and Phase Separation with the Third Component
Authors: Zhang Miao , Zhang Zhuohan , Wang Jian , An Qiaoshi , Peng Hongshang , Tang Weihua , Zhang Fujun
Published: July 2019

Ternary polymer solar cells (PSCs) are designed by incorporating varied PC71BM into a PBDB‐T:INPIC‐Si‐based binary system. The PC71BM incorporation can replenish weak absorption of PBDB‐T and INPIC‐Si in the short wavelength from 300 to 500 nm. Effective charge transport channels can be formed in ternary active layers due to good compatibility of the used materials. The optimized ternary PSCs exhibit a power conversion efficiency (PCE) of 13.26% with short‐circuit current density (JSC) of 20.98 mA cm−2, open‐circuit voltage of 0.892 V, and fill factor (FF) of 70.84%. The 13.26% PCE is among the top values for ternary PSCs with fullerene derivative and nonfullerene materials as acceptors. An approximately 12.5% PCE improvement is obtained compared with INPIC‐Si‐based binary PSCs, originating from simultaneously increased JSC and FF of the optimized ternary PSCs. The balanced photon harvesting is obtained in the whole wavelength range by regulating PC71BM content in acceptors, leading to increased JSC of ternary PSCs. The molecular arrangement and phase separation are well optimized in ternary blend films, resulting in the enhanced FF of ternary PSCs. The photogenerated exciton distribution is optimized according to optical field distribution of ternary active layers, which further support the JSC and FF improvement.
Persistence, dissipation kinetics, and waiting period of ethion on cucumber by gas chromatography‐electron capture detector
Authors: Wani Ashraf A. , Jan Ishrat , Mukhtar Malik , Dar Alamgir A. , Mubashir Sofi , Sofi Khurshid A. , Sofi Javid A. , Dar Irshad H.
Published: July 2019

This study investigated the persistence, half life, dissipation kinetics, and waiting period of ethion on cucumber by gas chromatography‐electron capture detector. The residue analysis of ethion on cucumber was carried out by spraying ethion 50EC 500 g a.i. ha−1 at fruit developing stage followed by another application at 10‐day interval and residue were estimated by validated a method on gas chromatography. The sample extraction and clean up was done by modified quick, easy, cheap, effective, rugged, and safe method. The average initial deposits of ethion on cucumber fruit were found to be 0.92 mg/kg, by following two applications at 10‐day interval of ethion 50EC at 500 g a.i. ha−1. Residues of ethion reached below limit of detection 0.05 mg/kg after 15 days at recommended dosage. Therefore a waiting period of 15 day is suggested to reduce the risk before consumption of cucumber fruit samples after following Good Agricultural Practices. These results would be helpful for safe use of ethion on cucumber and to prevent any health problem to consumers. Since the developed method is simple, sensitive, selective and repeatable, it can be extended for ethion based standardisation of herbal formulations containing cucumber and its use in pesticide industries.
Manifesting multidimensional creativity in a technology‐mediated online TESOL practicum course
Authors: Song Kim , Kim Sujin , Zhao Yuyang
Published: July 2019

This qualitative case study examined how creativity was manifested in a technology‐mediated online TESOL practicum course with six in‐service teachers in a midwestern U.S. teacher education program. The study defines creativity as ability to explore, adapt, take risks, collaborate, communicate, reflect on, and innovate with novel, unpredictable, and appropriate resources. To examine a research question of how creativity was manifested in an online practicum course, two main data sets were analyzed: VoiceThread projects (talks and texts) and final papers. Findings are presented under each of three themes of creativity in action: creativity as collaborative critical reflection, creativity transformed as new pedagogy, and creativity mediated by technology. First, creativity was exercised as collaborative participation by which practicum students shared ideas, suggestions, and resources through a high‐level reflexivity among peers through guided feedback. Second, creativity was translated as new linguistically and culturally responsive teaching‐oriented pedagogical plans and practices. Finally, innovative use of the instructional technology—teaching videos and VoiceThread—was the key to enhancing teachers’ critical and transformative view of their own teaching and to increasing opportunities to learn in a safe and collaborative communal space.
Framework Polymorphism and Modular Crystal Structures of Uranyl Vanadates of Divalent Cations: Synthesis and Characterization of M(UO2)(V2O7) (M = Ca, Sr) and Sr3(UO2)(V2O7)2
Authors: Chong Saehwa , Aksenov Sergey M. , Dal Bo Fabrice , Perry Samuel N. , Dimakopoulou Foteini , Burns Peter C.
Published: July 2019

Uranyl vanadate compounds with divalent cations, M(UO2)(V2O7) (M = Ca, Sr) and Sr3(UO2)(V2O7)2, were synthesized by flux crystal growth, and their crystal structures were solved using single‐crystal X‐ray diffraction data. Ca(UO2)V2O7 and Sr(UO2)V2O7 were synthesized from reactants with molar ratios M:U:V of 1:1:2 and identical heating conditions, and increasing the M:U:V ratio to 3:1:4 resulted in Sr3(UO2)(V2O7)2. Crystallographic data for M(UO2)V2O7 compounds are: a = 7.1774(18) Å, b = 6.7753(17) Å, c = 8.308(2) Å; V = 404.01(18) Å3; space group Pmn21, Z = 2 for Ca; a = 13.4816(11) Å, b = 7.3218(6) Å, c = 8.4886(7) Å; V = 837.91(12) Å3; space group Pnma, Z = 4 for Sr. Compound Sr3(UO2)(V2O7)2 has a = 6.891(3) Å, b = 7.171(3) Å, c = 14.696(6) Å, α = 85.201(4)˚, β = 78.003(4)˚, γ = 89.188(4)˚; V = 707.9(5) Å3; space group P1, Z = 2. The framework structure of Sr(UO2)(V2O7) is related to that of Pb(UO2)(V2O7) reported previously, while that of Ca(UO2)(V2O7) has a different topology. The topological polymorphism of the [(UO2)(V2O7)]‐type framework may be due to the differing ionic radii of the guest M2+ cations. Compound Sr3(UO2)(V2O7)2 has a modular structure based on two different types of electroneutral layers: [Sr(UO2)(V2O7)] and [Sr2(V2O7)]. Structural complexities were calculated, and Raman spectra were collected and their peaks were assigned.
Open exceptional strings and D-branes
Authors: Blair Chris D.A.
Published: July 2019

Abstract

We study D-branes in the extended geometry appearing in exceptional field theory (or exceptional generalised geometry). Starting from the exceptional sigma model (an E
d(d) covariant worldsheet action with extra target space coordinates), we define open string boundary conditions. We write down Neumann and Dirichlet projectors compatible with the preservation of half-maximal supersymmetry by the brane (building on previous work on the definition of generalised orientifold quotients in exceptional field theory). This leads to a definition of D-branes, plus their S-duals, as particular subspaces of the exceptional geometry, and provides an opportunity to study D-branes in U-fold backgrounds.
Multiple Solutions with Sign Information for a Class of Parametric Superlinear (p, 2)-Equations
Authors: Gasiński Leszek , Papageorgiou Nikolaos S.
Published: July 2019

We consider a parametric nonlinear, nonhomogeneous Dirichlet problem driven by the sum of a p-Laplacian (with $$p>2$$

p
>
2

) and a Laplacian (a two phase equation). The reaction consists of a parametric $$(p-1)$$

(
p
-
1
)

-superlinear term and a $$(p-1)$$

(
p
-
1
)

-sublinear perturbation. We show that for all $$\lambda >0$$

λ
>
0

big, the problem has at least three nontrivial smooth solutions, all with sign information. Also we determine their asymptotic behaviour as the parameter $$\lambda \rightarrow \infty $$

λ
→
∞

. When we strengthen the regularity of the perturbation term, we produce a second nodal solution, for a total of four solutions, all with sign information.
Language impairment in progressive supranuclear palsy and corticobasal syndrome
Authors: Peterson Katie A. , Patterson Karalyn , Rowe James B.
Published: July 2019

Although commonly known as movement disorders, progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) may present with changes in speech and language alongside or even before motor symptoms. The differential diagnosis of these two disorders can be challenging, especially in the early stages. Here we review their impact on speech and language. We discuss the neurobiological and clinical-phenomenological overlap of PSP and CBS with each other, and with other disorders including non-fluent agrammatic primary progressive aphasia and primary progressive apraxia of speech. Because language impairment is often an early and persistent problem in CBS and PSP, there is a need for improved methods for language screening in primary and secondary care, and more detailed language assessments in tertiary healthcare settings. Improved language assessment may aid differential diagnosis as well as inform clinical management decisions.