bluuebunny/crossref_metadata_2025 huggingface dataset:
Contrast‐Enhanced MRI Combined With the Glycerol Test Reveals the Heterogeneous Dynamics of Endolymphatic Hydrops in Patients With Menière's Disease
Authors: Wang Pengjun , Yu Dongzhen , Wang Hui , Ye Haibo , Qiao Ruihua , Chen Zhengnong , Wu Yaqin , Li Yuehua , Shi Haibo , Zou Jing , Yin Shankai
Published: March 2020

Background

The sensitivity of endolymphatic hydrops (EH) to the glycerol test varies in patients with Menière's disease (MD).

Purpose

To explore the features of EH and its glycerol‐induced dynamics in MD.

Study Type

Case–control study.

Population

Twenty patients with MD (24 affected ears) were included.

Field Strength/Sequence

3.0T 3D‐FLAIR (fluid‐attenuated inversion recovery) MRI and late gadolinium enhancement.

Assessment

Intratympanic gadolinium‐enhanced MRI was performed in the MD‐affected ears before and after the glycerol test. The borders of the endolymphatic and total lymphatic space were contoured on the axial MRI slices to evaluate the volume of hydrops in both the cochlear and vestibular regions.

Statistical Tests

Paired and unpaired t‐tests, the Mann–Whitney U‐test, linear discriminant analysis, Pearson's correlation, and linear regression.

Results

After glycerol ingestion, vestibular EH decreased in all patients, whereas cochlear EH significantly decreased only in patients with positive glycerol test results (all P < 0.01). At baseline, cochlear EH in the positive result group was greater than in the negative result group (P = 0.007). Unexpectedly, in the positive result group a drastic glycerol‐induced dehydrating effect was observed in patients whose pretest cochlear EH ratio was >16% (P = 0.011). Moreover, the dehydrating role of glycerol was positively correlated with the baseline cochlear hydrops level (r = 0.7691, P < 0.001).

Data Conclusion

MRI provides evidence that glycerol administration improves the hearing threshold via dehydrating the EH. In the cochlear region, the baseline level of cochlear EH is a closely related factor for the validity of the glycerol test, whereas EH is consistently dehydrated in the vestibular component.

Level of Evidence

2

Technical Efficacy Stage

3 J. Magn. Reson. Imaging 2020;52:1066–1073.
Antigenic drift of hemagglutinin and neuraminidase in seasonal H1N1 influenza viruses from Saudi Arabia in 2014 to 2015
Authors: Naeem Asif , Elbakkouri Karim , Alfaiz Ali , Hamed Maaweya E. , Alsaran Hadel , AlOtaiby Shahad , Enani Mushira , Alosaimi Bandar
Published: March 2020

Antigenic drift of the hemagglutinin (HA) and neuraminidase (NA) proteins of the influenza virus cause a decrease in vaccine efficacy. Since the information about the evolution of these viruses in Saudi is deficient so we investigated the genetic diversity of circulating H1N1 viruses. Nasopharyngeal aspirates/swabs collected from 149 patients hospitalized with flu‐like symptoms during 2014 and 2015 were analyzed. Viral RNA extraction was followed by a reverse transcription‐polymerase chain reaction and genetic sequencing. We analyzed complete gene sequences of HA and NA from 80 positive isolates. Phylogenetic analysis of HA and NA genes of 80 isolates showed similar topologies and co‐circulation of clades 6b. Genetic diversity was observed among circulating viruses belonging to clade 6B.1A. The amino acid residues in the HA epitope domain were under purifying selection. Amino acid changes at key antigenic sites, such as position S101N, S179N (antigenic site‐Sa), I233T (antigenic site‐Sb) in the head domain might have resulted in antigenic drift and emergence of variant viruses. For NA protein, 36% isolates showed the presence of amino acid changes such as V13I (n = 29), I314M (n = 29) and 12% had I34V (n = 10). However, H257Y mutation responsible for resistance to neuraminidase inhibitors was missing. The presence of amino acid changes at key antigenic sites and their topologies with structural mapping of residues under purifying selection highlights the importance of antigenic drift and warrants further characterization of recently circulating viruses in view of vaccine effectiveness. The co‐circulation of several clades and the predominance of clade 6B.1 suggest multiple introductions in Saudi.
Computation of quantum‐corrected noise in graphene‐SiC‐based impact avalanche transit time diode
Authors: Ghivela Girish C. , Sengupta Joydeep
Published: March 2020

Here, we have performed the noise analysis in graphene‐SiC‐based double drift region impact avalanche transit time diode (IMPATT). For computation, the noise model taken is based on drift diffusion with quantum corrections. Though noise computation in IMPATT with classical drift diffusion model are widely followed in earlier years, noise analysis through classical drift diffusion model is independent of confinement and tunneling due to quantum effects. Noise computed through quantum‐corrected noise model is more accurate to measured noise. Therefore, by considering quantum effects in addition to classical noise model, we have computed the noise in graphene‐SiC IMPATT. The noise performance of graphene‐SiC IMPATT is evaluated at Ka band which ranges from 26.5 to 40 GHz. The obtained noise from graphene‐SiC IMPATT is in good agreement with earlier reported noise behavior in IMPATT. We observed that the graphene‐SiC IMPATT is giving the better noise performance in terms of lower computed noise and noise spectral density as compared to other materials reported so far.
Optical Imaging of Coherent Molecular Rotors
Authors: Bert Jérémy , Prost Emilien , Tutunnikov Ilia , Béjot Pierre , Hertz Edouard , Billard Franck , Lavorel Bruno , Steinitz Uri , Averbukh Ilya Sh. , Faucher Olivier
Published: March 2020

Short laser pulses are widely used for controlling molecular rotational degrees of freedom and inducing molecular alignment, orientation, unidirectional rotation, and other types of coherent rotational motion. To follow the ultrafast rotational dynamics in real time, several techniques for producing molecular movies have been proposed based on the Coulomb explosion of rotating molecules, or recovering molecular orientation from the angular distribution of high harmonics. The present work offers and demonstrates a novel nondestructive optical method for direct visualization and recording of movies of coherent rotational dynamics in a molecular gas. The technique is based on imaging the time‐dependent polarization dynamics of a probe light propagating through a gas of coherently rotating molecules. The probe pulse continues through a radial polarizer, and is then recorded by a camera. The technique is illustrated by implementing it with two examples of time‐resolved rotational dynamics: alignment–antialignment cycles in a molecular gas excited by a single linearly polarized laser pulse, and unidirectional molecular rotation induced by a pulse with twisted polarization. This method may open new avenues in studies on fast chemical transformation phenomena and ultrafast molecular dynamics caused by strong laser fields of various complexities.
Gut microbial diversity and stabilizing functions enhance the plateau adaptability of Tibetan wild ass (Equus kiang)
Authors: Gao Hongmei , Chi Xiangwen , Li Guangying , Qin Wen , Song Pengfei , Jiang Feng , Liu Daoxin , Zhang Jingjie , Zhou Xiaowen , Li Shengqing , Zhang Tongzuo
Published: March 2020

Interactions between gut microbiota not only regulate physical health, but also form a vital bridge between the environment and the host, thus helping the host to better adapt to the environment. The improvement of modern molecular sequencing techniques enables in‐depth investigations of the gut microbiota of vertebrate herbivores without harming them. By sequencing the 16S rRNA V4‐V5 region of the gut microbiota of both the captive and wild kiang in winter and summer, the diversity and function of the microbiota could be compared. The reasons for observed differences were discussed. The results showed that the dominant phyla of the kiang were Bacteroidetes and Firmicutes, and the structure and abundance of the gut microbiota differed significantly between seasons and environments. However, the relatively stable function of the gut microbiota supplies the host with increased adaptability to the environment. The diversity of the intestinal flora of the kiang is relatively low in captivity, which increases their risk to catch diseases to some extent. Therefore, importance should be attached to the impact of captivity on wildlife.
XB130, regulated by miR‐203, miR‐219, and miR‐4782‐3p, mediates the proliferation and metastasis of non‐small‐cell lung cancer cells
Authors: Wang Qinrong , Yang Guohui , Jiang Yinhui , Luo Mei , Li Chao , Zhao Yan , Xie Yuan , Song Kewei , Zhou Jianjiang
Published: March 2020

XB130 is a novel adapter protein that behaves as a tumor promoter or suppressor mediating cell proliferation and metastasis in the development of different human tumors. Altered expression of XB130 has been verified in human non‐small cell‐lung cancer (NSCLC). However, the exact effect of XB130 on NSCLC is not well‐understood. In this study, we investigated the biological function and posttranscriptional regulation of XB130 in NSCLC. First, the effects of XB130 silence on NSCLC cell proliferation, migration, invasion, and epithelial‐mesenchymal transition (EMT) were examined. Then the targeting relationship between XB130 and miR‐203, miR‐219, or miR‐4782‐3p was demonstrated by dual‐luciferase reporter assay. Finally, the effects of miR‐203, miR‐219, and miR‐4782‐3p on NSCLC cell function were studied, respectively. We found that XB130 silence significantly inhibited cell growth, migration and invasion, and reversed EMT. Furthermore, XB130 was posttranscriptionally regulated by miR‐203, miR‐219, and miR‐4782‐3p. Overexpression of miR‐203, miR‐219, or miR‐4782‐3p inhibited cell growth, migration and invasion, and reversed EMT, just like the role of XB130 in NSCLC cells, whereas the suppressive effects of microRNA (miRNA) overexpression were weakened by miRNA inhibitors or ectopic expression of XB130 in NSCLC cells. These data demonstrate that XB130 is posttranscriptionally regulated by miR‐203, miR‐219, and miR‐4782‐3p and mediates the proliferation and metastasis of NSCLC cells.
Disabling Myoclonus in a Case of Joubert Syndrome
Authors: Holla Vikram Venkappayya , Stezin Albert , Chaithra Sudhakar Pushpa , Kamble Nitish , Yadav Ravi , Pal Pramod Kumar
Published: March 2020

View Supplementary Video 1
Reliable and accurate needle localization in curvilinear ultrasound images using signature‐based analysis of ultrasound beamformed radio frequency signals
Authors: Daoud Mohammad I. , Abu‐Hani Ayah F. , Alazrai Rami
Published: March 2020

Purpose

Ultrasound imaging is used in many minimally invasive needle insertion procedures to track the advancing needle, but localizing the needle in ultrasound images can be challenging, particularly at steep insertion angles. Previous methods have been introduced to localize the needle in ultrasound images, but the majority of these methods are based on ultrasound B‐mode image analysis that is affected by the needle visibility. To address this limitation, we propose a two‐phase, signature‐based method to achieve reliable and accurate needle localization in curvilinear ultrasound images based on the beamformed radio frequency (RF) signals that are acquired using conventional ultrasound imaging systems.

Methods

In the first phase of our proposed method, the beamformed RF signals are divided into overlapping segments and these segments are processed to extract needle‐specific features to identify the needle echoes. The features are analyzed using a support vector machine classifier to synthesize a quantitative image that highlights the needle. The quantitative image is processed using the Radon transform to achieve a reliable and accurate signature‐based estimation of the needle axis. In the second phase, the accuracy of the needle axis estimation is improved by processing the RF samples located around the signature‐based estimation of the needle axis using local phase analysis combined with the Radon transform. Moreover, a probabilistic approach is employed to identify the needle tip. The proposed method is used to localize needles with two different sizes inserted in ex vivo animal tissue specimens at various insertion angles.

Results

Our proposed method achieved reliable and accurate needle localization for an extended range of needle insertion angles with failure rates of 0% and mean angle, axis, and tip errors smaller than or equal to

, 0.6 mm, and 0.7 mm, respectively. Moreover, our proposed method outperformed a recently introduced needle localization method that is based on B‐mode image analysis.

Conclusions

These results suggest the potential of employing our signature‐based method to achieve reliable and accurate needle localization during ultrasound‐guided needle insertion procedures.
Few‐shot learning with deformable convolution for multiscale lesion detection in mammography
Authors: Li Ce , Zhang Dong , Tian Zhiqiang , Du Shaoyi , Qu Yanyun
Published: March 2020

Purpose

Image‐based breast lesion detection is a powerful clinical diagnosis technology. In recent years, deep learning architectures have achieved considerable success in medical image analysis however, they always require large‐scale samples. In mammography images, breast lesions are inconspicuous, multiscale, and have blurred edges. Moreover, few well‐labeled images exist. Because of these factors, the detection accuracy of conventional deep learning methods is low. Therefore, we attempted to improve the accuracy of mammary lesion detection by introducing transfer learning (TL) into a deep learning framework for the few‐shot learning task and thus provide a method that will further assist physicians in detecting breast lesions.

Methods

In this paper, we propose a method called “few‐shot learning with deformable convolution for multiscale lesion detection in mammography,” named FDMNet. Deformable convolution is introduced for enhancing the network’s ability to detect lesions, and the sensitivity of the multiscale feature space is reinforced by using a feature pyramid method. Furthermore, by introducing location information in the predictor, the sensitivity of the model to lesion location is also enhanced. The proposed method, through the TL technique that is applied mines the potentially common knowledge of features in the source domain and transfers it into the target domain to improve the accuracy of breast lesion detection in the few‐shot learning task.

Results

On the publicly available datasets for screening mammography CBIS‐DDSM and Mini‐MIAS, the proposed method performs better than five widely used detection methods. On the CBIS‐DDSM dataset, its comprehensive scores, sensitivity, precision, and the mean dice similarity coefficient are 0.911, 0.949, 0.873, and 0.913, respectively, and on the Mini‐MIAS dataset, these values are 0.931, 0.966, 0.882, and 0.941, respectively.

Conclusions

To achieve the few‐shot learning required for medical image analysis, the proposed method uses TL to execute feature knowledge transformation and includes deformable convolution to build a feature pyramid structure, which enhances the learning performance of the network for lesions. The results of comparative numerical experiments show that the proposed method outperforms some state‐of‐the‐art methods.
Joint‐aggregation intumescent flame‐retardant effect of ammonium polyphosphate and charring agent in polypropylene
Authors: Tang Wei , Qian Lijun , Chen Yajun , Qiu Yong , Xu Bo , Li Juan
Published: March 2020

In order to explore the structure mode of intumescent flame retardants (IFRs) with higher efficiency, IFR particles with joint‐aggregation structure (@IFR) were obtained through the treatment of ammonium polyphosphate (APP) and a charring agent (PT‐Cluster) in their aqueous solution. Then, the joint‐aggregation IFR effect was researched using its application in polypropylene. In case of 20 wt% IFR loading, the limiting oxygen index (LOI) value of @IFR/PP was 1.1% higher than that of 15APP/5PT‐Cluster/PP mixture, and a 1.6 mm‐thick @IFR/PP composite passed the UL 94 V‐2 rating test, while 15APP/5PT‐Cluster/PP demonstrated no flame‐retardant rating in UL 94 vertical burning tests. In a cone calorimeter test, @IFR also had a better inhibition effect on heat release. The average heat release rate (av‐HRR) value during 0 to 120 seconds of @IFR/PP was only 41 kW m−2, which was 33.9% lower than that of the 15APP/5PT‐Cluster/PP. Furthermore, the peak heat release rate (pk‐HRR) of @IFR/PP was 20.5% lower than that of 15APP/5PT‐Cluster/PP, and the time to pk‐HRR of @IFR/PP was 710 seconds, while that of 15APP/5PT‐Cluster/PP was 580 seconds. The better inhibition effect on HRR and the delay of time to pk‐HRR were caused by the joint‐aggregated structure of @IFR, which can rapidly react to form stable and efficient char layers. This kind of join‐aggregation IFR effect has great significance in suppressing the spread of fire in reality. In addition, @IFR also increased the mechanical properties of PP composites slightly compared with the APP/PT‐Cluster mixture.
Addressing implicit bias in pediatric hematology‐oncology
Authors: Tsai Jessica W. , Kesselheim Jennifer C.
Published: March 2020

Although awareness of implicit bias and its influence on providers and patients is increasing, the effects of implicit bias on the field of pediatric hematology‐oncology are less clear. This Special Report reviews the literature on implicit bias in pediatrics and medical oncology and further provides case examples and suggestions on what can be done to address implicit bias. There is a need for further research on how implicit bias impacts the complex care of pediatric hematology‐oncology patients.
Novel electrospun polymer electrolytes incorporated with Keggin‐type hetero polyoxometalate fillers as solvent‐free electrolytes for lithium ion batteries
Authors: Banitaba Seyedeh Nooshin , Semnani Dariush , Heydari‐Soureshjani Elahe , Rezaei Behzad , Ensafi Ali A , Taghipour‐Jahromi Ahmadreza
Published: March 2020

In this study, solvent‐free nanofibrous electrolytes were fabricated through an electrospinning method. Polyethylene oxide (PEO), lithium perchlorate and ethylene carbonate were used as polymer matrix, salt and plasticizer respectively in the electrolyte structures. Keggin‐type hetero polyoxometalate (Cu‐POM@Ru‐rGO, Ni‐POM@Ru‐rGO and Co‐POM@Ru‐rGO (POM, polyoxometalate; rGO, reduced graphene oxide)) nanoparticles were synthesized and inserted into the PEO‐based nanofibrous electrolytes. TEM and SEM analyses were carried out for further evaluation of the synthesized filler structures and the electrospun nanofibre morphologies. The fractions of free ions and crystalline phases of the as‐spun electrolytes were estimated by obtaining Fourier transform infrared and XRD spectra, respectively. The results showed a significant improvement in the ionic conductivity of the nanofibrous electrolytes by increasing filler concentrations. The highest ionic conductivity of 0.28 mS cm−1 was obtained by the introduction of 0.49 wt% Co‐POM@Ru‐rGO into the electrospun electrolyte at ambient temperature. Compared with solution‐cast polymeric electrolytes, the electrospun electrolytes present superior ionic conductivity. Moreover, the cycle stability of the as‐spun electrolytes was clearly improved by the addition of fillers. Furthermore, the mechanical strength was enhanced with the insertion of 0.07 wt% fillers to the electrospun electrolytes. The results implied that the prepared nanofibres are good candidates as solvent‐free electrolytes for lithium ion batteries. © 2020 Society of Chemical Industry
Fluorescence Turn‐On Analysis of Trace Protein Based on Carbon Nanodots and Hybridization Chain Reaction
Authors: Yang Dawei , Zhang Xujia , Kou Xinyue , Shao Xuejun , Miao Peng
Published: March 2020

In this work, an ultrasensitive method for trace protein detection based on fluorescent carbon nanodots and hybridization chain reaction (HCR) is designed. Generally, the synthesized bright carbon nanodots are conjugated with two hairpin‐structured DNA probes, respectively, which act as subsequent HCR fuel strands. Since single‐stranded parts of DNA probes could be easily absorbed on graphene oxide (GO) nanosheets, fluorescence emission of carbon nanodots is effectively quenched via fluorescence resonance energy transfer. However, in the presence of target protein, the aptamer sequence in another hairpin‐structured DNA probe specially interacts with target and the hairpin is opened. A single‐stranded region is thus exposed, which initiates HCR by coupling with the DNA fuel strands on carbon nanodots. The formed HCR product displays a rigid, long double‐stranded structure, which facilitates the release of carbon nanodots from GO surface. As a result, fluorescence of carbon nanodots is recovered and initial concentration of target protein can be estimated. This protein detection method shows a favorable linear response with a low limit of detection (2.3 fg mL−1). Furthermore, it is highly selective and capable of detecting target in biological fluids like serum samples, which demonstrates the promising applications of this method.
Nonempirical (double‐hybrid) density functionals applied to atomic excitation energies: A systematic basis set investigation
Authors: Hernández‐Martínez Laura , Brémond Eric , Pérez‐Jiménez Angel J. , San‐Fabián Emilio , Adamo Carlo , Sancho‐García Juan C.
Published: March 2020

We investigate here the lowest‐energy (spin‐conserving) excitation energies for the set of He‐Ne atoms, with the family of nonempirical PBE, PBE0, PBE0‐1/3, PBE0‐DH, PBE‐CIDH, PBE‐QIDH, and PBE0‐2 functionals, after employing a wide variety of basis sets systematically approaching the basis set limit: def2‐nVP(D), cc‐pVnZ, aug‐cc‐pVnZ, and d‐aug‐cc‐pVnZ. We find that an accuracy (ie, mean unsigned error) of 0.3 to 0.4 eV for time‐dependent density functional theory (DFT) atomic excitation energies can be robustly achieved with modern double‐hybrid methods, which are also stable with respect to the addition of a double set of diffuse functions, contrarily to hybrid versions, in agreement with recent findings employing sophisticated multiconfigurational DFT methods.
Facile Synthesis, Spectral (IR, Mass, UV−Vis, NMR), Linear and Nonlinear Investigation of the Novel Phosphonate Compounds: A Combined Experimental and Simulation Study
Authors: Khalid Muhammad , Ali Akbar , De la Torre Alexander F. , Marrugo Kelly P. , Concepcion Odette , Kamal Ghulam Mustafa , Muhammad Shabbir , Al‐Sehemi Abdullah G.
Published: March 2020

Herein, we reported the imino phosphonate compounds: (4‐methoxy‐benzylidene‐amino‐phenyl‐methyl‐phosphonic acid diethyl ester (MBPDE), 4‐hydroxy‐benzylidene‐amino‐phenyl‐methyl‐phosphonic acid diethyl ester (HBPDE) and 4‐hydroxy‐3‐methoxy‐benzylidene‐amino‐phenyl‐methyl‐phosphonic acid diethyl ester (HMBPD) form the chemical reaction of diethyl (α‐amino benzyl)phosphonate hydrochloride and substituted benzaldehyde. These compounds were characterized by various spectroscopic techniques: FT‐IR, Mass, UV–VIS, 1H NMR and 13 C NMR. Additionally, the optimized molecular structures, FT‐IR, natural bond orbitals (NBOs), frontier molecular orbitals (FMOs), non‐linear optical (NLO) properties were calculated by the density functional theory (DFT) using the B3LYP functional with the 6–311+G(d,p) basis set. Moreover, UV–Visible spectrum of MBPDE, HBPDE and HMBPD were predicted in different solvents using the time dependent TD‐DFT [B3LYP/6‐311+G(d,p)] method using Polarizable Continuum Model (PCM). The non‐linear optical (NLO) properties were calculated by M06 functional with the 6–311+G(d,p) basis set. A synergistic relationship is observed between the experimental and theoretical findings. NBO analysis provided insights about the stability and charge delocalization of the entitled molecules. The global reactivity descriptors were achieved through HOMO‐LUMO energies. The efficiency of the entitled molecules concerning charge transfer and participation in diverse chemical reactivities were figured out perceptibly by applying the frontier molecular orbitals (FMOs) analysis. The average polarizability
values: 277.184, 261.332 and 280.254 a.u. of the MBPDE, HBPDE and HMBPD were determined respectively. The total first hyperpolarizability (βtot) values of the MBPDE, HBPDE and HMBPD were also obtained to be 992.900, 781.527 and 1107.526 a.u. respectively. The compound HMBPD comprising of higher magnitude of average polarizability and the total first hyperpolarizability (βtot) values than MBPDE and HBPDE molecules. Moreover, NLO properties of urea molecule were found smaller in comparison to the MBPDE, HBPDE and HMBPD. The medicinal importances of these novel compounds as well as its contribution towards nonlinear optical field are our future targets.
A Facile Formation of Vanadium(0) by the Reduction of Vanadium Pentoxide Pelletized with Magnesium Oxide Enabled by Microwave Irradiation
Authors: Inazu Naomi , Suzuki Eiichi , Fujii Satoshi , Tsubaki Shuntaro , Wada Yuji
Published: March 2020

The reduction of V2O5 to vanadium metal(0), that requires severe conditions in conventional reduction methods, was enabled to be proceeded in a short time of 1 h at 1273 K by the reaction with magnesium vapor with the isolation yield of V(0) in 55.6% by using microwave irradiation of 820 W. A pressurized pelletization of powdery V2O5 well‐mixed with MgO powder at a specific mixing ratio followed by calcination in ambient air at 1173 K was crucial for the reaction since a complex oxide of MgV2O4, presumably as a precursor, was formed in calcination of the V2O5/MgO pellet to be reduced to V(0) by the reaction with magnesium. Calcination of V2O5/MgO pellets with different mixing ratios or different temperatures resulted in the formation of different kinds of complex oxide of vanadium and magnesium such as α‐Mg2V2O7, Mg3(VO4)2, triclinic Mg2V2O7, and MgV2O6. While the yield of V(0) was dependent on the kind of the complex oxide, formation of MgV2O4 was essential as the precursor to the formation of V(0).
Sonogashira Coupling (Cu/Amine‐Free) of ArBr/Cl in Aerobic Condition and N‐Benzylation of Aniline with Benzyl Alcohol Catalyzed by Complexes of Pd(II) with Sulfated/Selenated NHCs
Authors: Dubey Pooja , Singh Ajai K.
Published: March 2020

The moisture and air insensitive, and thermally stable [Pd(L1/L2‐H)Cl][PF6] (1/2) and [Pd(L3/L4‐HI)Cl2] (3/4) catalyze N‐benzylation of aniline (at 100 °C) and Sonogashira coupling of ArBr/Cl (at 80 °C) in the presence of KOH and K2CO3 respectively. The optimum catalyst loading (mol %) is 0.02‐0.1 for the C−C coupling and 0.5 for N‐benzylation. The 1–4 were found reusable. The L1/L2=3‐(1‐benzyl‐1H‐1,2,3‐triazol‐4‐yl)methyl)‐1‐(2‐(phenyl thio/seleno)ethyl)‐1H‐benzo[d]imidazol‐3‐ium hexafluorophosphate and L3/L4=4‐methyl‐1‐(2‐(phenylthio/seleno)ethyl)‐1H‐1,2,4‐triazol‐4‐ium iodide are precursors of N‐heterocyclic carbenes. Copper‐catalyzed click reaction gave L1/L2. The treatment of triazole with ClCH2CH2Cl, [PhS/Se]−Na+ and MeI successively afforded L3/L4. The sequence of reactions of L1‐L4 with Ag2O and [Pd(CH3CN)2Cl2] (M : L=1 : 1) gave 1–4. The L1‐L4 and 1–4 were characterized by elemental analyses, multi‐nuclei NMR, HR‐MS and single‐crystal structure (3 and 4). The geometry of Pd in 3/4 is nearly square planar. The bond distances (Å) in 3/4 are: Pd−S/Se, 2.3040(7)/2.402(2) and Pd−C, 1.961(3)/1.938(11).
Effect of Flower‐Like and Spherical Nanostructured MoS2 on the Adsorption Properties of Cr(VI) Ions
Authors: Fan Honglei , Wang Shuzhan , Qin Zeyun , Wang Haidong , Zhou Shaofeng , Liu Yaqing
Published: March 2020

MoS2 nanostructures with different morphologies were synthesized using a simple in‐situ hydrothermal process by different surfactants like hexadecyl trimethyl ammonium bromide (CTAB) and polyvinyl pyrrolidone (PVP), and the effect of morphologies on the adsorption property for Cr(VI) were investigated. It can be found that flower‐like and spherical MoS2 nanostructures were synthesized and their morphologies largely effected the adsorption performance toward Cr(VI) ions. Flower‐like MoS2 exhibited the surface area of 41.9 m2 g−1 with fairly high adsorption capacity of 66.1 mg g−1 toward Cr(VI), fitting well to pseudo‐second order kinetic model and Langmuir isotherm model. Moreover, this as‐prepared nanostructured MoS2 also presented satisfying reusability for removal of Cr(VI) and were even suitable for the selective removal of Cr(VI) in the presence of NO3−. It may provide a potential route to enhance the adsorption property of MoS2 toward heavy metal ions through adjusting the morphology of the MoS2 sample, which would expand the applications of MoS2 in the field of treatment of the heavy metal wastewater.
Aerobic α‐Sulfonylation of Ketones with Zinc Sulfinates in Aqueous Micellar Media: Highly Selective Access to β‐Keto Sulfones
Authors: Fu Ying , Li Quan‐Zhou , Li Ming‐Peng , Du Zhengyin
Published: March 2020

An efficient, inexpensive and environmentally friendly synthesis of β‐ketosulfones, via NaI‐catalyzed oxidative sulfonylation of ketones with zinc sulfinates, employing ethylene dibromide (EDB) and air as the oxidants, is described. EDB was shown to be a mild organic oxidant to convert NaI into molecular iodine that promote the cross‐coupling reactions of zinc sulfinates with ketones, producing β‐ketosulfones. Mechanistic studies indicated that a radical pathway might be involved in the reaction process. The key feature of the present protocol is the far greater solubility of NaI and sulfinates in micellar arrays present in aqueous solution where the oxidative coupling reactions are taking place.
Recent Advances in Improving Phase Stability of Perovskite Solar Cells
Authors: Qiu Zhiwen , Li Nengxu , Huang Zijian , Chen Qi , Zhou Huanping
Published: March 2020

Organic–inorganic hybrid perovskite solar cells (PSCs) have demonstrated high efficiency and improved stability, which shows promising potential for commercialization. However, among all challenges, the material and device instability of the methylammonium lead iodide (MAPbI3) absorber are regarded as serious obstacles to the future development of devices for long‐term operation. Compared with conventional MAPbI3, formamidinium lead iodide (FAPbI3) and cesium lead iodide (CsPbI3) have attracted more attention due to their superior thermal stability. Due to their undesirable tolerant factor, however, these materials suffer from poor phase stability, which is worthy of careful investigation. This perspective highlights the recent progress on the phase stabilization of FAPbI3 and inorganic CsPbI3 materials with emphasis on the fundamental understanding of the origin of phase instability. In addition, strategies to fabricate corresponding devices toward high‐efficiency and long‐lifetime are discussed. This review sheds light onto the design and synthesis of FAPbI3 and inorganic CsPbI3 perovskite materials. In the end, the potential of FAPbI3 and inorganic CsPbI3 perovskite materials as stable absorbers is discussed, which promotes the development of corresponding solar cells and other optoelectronic devices for practical applications.
Low‐Temperature‐Processed Zr/F Co‐Doped SnO2 Electron Transport Layer for High‐Efficiency Planar Perovskite Solar Cells
Authors: Tian Jiawu , Zhang Jianjun , Li Xiaohe , Cheng Bei , Yu Jiaguo , Ho Wingkei
Published: March 2020

The energy band position and conductivity of electron transport layers (ETLs) are essential factors that restrict the efficiency of planar perovskite solar cells (p‐PSCs). Tin oxide (SnO2) has become a primary material in ETLs due to its mild synthesis condition, but its low conduction band position and limited intrinsic carriers are disadvantageous in electron transport. To solve these problems, this work exquisitely designs a Zr/F co‐doped SnO2 ETL. The doping of Zr can raise the conduction band of SnO2, which reduces the energy barrier in electron extraction and inhibits the interface recombination between the ETL and perovskite. The open‐circuit voltage (VOC) of p‐PSCs consequently increases. F− doping belongs to n‐type doping. Thus, it equips SnO2 with a large number of free electrons and improves the conductivity of the ETL and short‐circuit current (JSC). The device based on Zr/F co‐doped ETL achieves a high efficiency of 19.19% and exhibits a reduced hysteresis effect, which is more satisfactory than that of a pristine device (17.35%). Overall, this research successfully adjusts the energy band match and boosts the conductivity of ETL via Zr/F co‐doping. The results provide an effective strategy for fabricating high‐efficiency p‐PSCs.
Computational DFT study of magnetite/graphene oxide nanoadsorbent: Interfacial chemical behavior and remediation performance of heavy metal hydrates from aqueous system
Authors: El‐Fawal Esraa M. , Saad Lamia , Moustafa Yasser M.
Published: March 2020

Herein, magnetite/graphene oxide hybrid (MGO) was facilely synthesized and analyzed by various techniques such as X‐ray diffraction spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, Brunauer, Emmett, and Teller surface area analyzer, and Raman spectroscopy. A computational density functional theory (DFT) has been applied for the first time to determine the removal mechanism of zinc (Zn2+), nickel (Ni2+), and chromium (Cr6+) hydrates onto the prepared MGO. The adsorption binding energy and geometries of the metal hydrates with oxygen functional group (i.e., hydroxyl, epoxide, carboxylic, carbonyl groups, and magnetite on the MGO surface) were estimated. The complexes configurations comprised via sitting the metal ion perpendicular and above the MGO surface. The zinc hydrate portended to bind more strongly than Ni2+ and Cr6+. Zinc hydrate is favorable to coordinate with hydroxyl and carboxylic group than the other functional groups. The pseudo‐second‐order kinetic and Langmuir isotherm models are well convenient for kinetics and isotherm sorption process, respectively. The results determined that the sorption of heavy metals by nanostructure MGO was observed in the following order: zinc > nickel > chromium as revealed by the DFT computations. The maximum adsorption capacity of Zn2+, Ni2+, and Cr6+ was 333, 250, and 200 mg/g, respectively. Thermodynamic constants depicted that the sorption process is naturally instantaneous and exothermic. The calculated predicted results are fitted with the experimental results.

Practitioner points

Combination of MGO with DFT calculations in the sorption of Zn, Ni, and Cr hydrates.

MGO applied on the removal of Zn+2, Ni+2, and Cr+6 with high sorption capacity.

DFT calculations revealed that Zn hydrate is more favorably adsorbed than others.

DFT calculations proved that ZnOH is favorable to coordinate with OH and COOH groups.

DFT calculation offers guidance on the mechanism of coordination of heavy metals.
T, Q and periods in SU(3) $$ \mathcal{N} $$ = 2 SYM
Authors: Fioravanti Davide , Poghosyan Hasmik , Poghossian Rubik
Published: March 2020

Abstract

We consider the third order differential equation derived from the deformed Seiberg-Witten differential for pure $$ \mathcal{N} $$
N
= 2 SYM with gauge group SU(3) in Nekrasov- Shatashvili limit of Ω-background. We show that this is the same differential equation that emerges in the context of Ordinary Differential Equation/Integrable Models (ODE/IM) correspondence for 2d A2 Toda CFT with central charge c = 98. We derive the corresponding QQ and related T Q functional relations and establish the asymptotic behaviour of Q and T functions at small instanton parameter q → 0. Moreover, numerical integration of the Floquet monodromy matrix of the differential equation leads to evaluation of the A-cycles a1,2,3 at any point of the moduli space of vacua parametrized by the vector multiplet scalar VEVs (tr 𝜙2) and (tr 𝜙3) even for large values of q which are well beyond the reach of instanton calculus. The numerical results at small q are in excellent agreement with instanton calculation. We conjecture a very simple relation between Baxter’s T -function and A-cycle periods a1,2,3, which is an extension of Alexei Zamolodchikov’s conjecture about Mathieu equation.
Investigation of nutritional characteristics and free radical scavenging activity of wild apple, pear, rosehip, and barberry from the walnut-fruit forests of Kyrgyzstan
Authors: Smanalieva Jamila , Iskakova Janyl , Oskonbaeva Zhyldyz , Wichern Florian , Darr Dietrich
Published: March 2020

This study is based on 2-year experimental results aimed at evaluating the nutritional value and pomological characteristics of wild fruits and berries from the walnut-fruit forests of southern Kyrgyzstan including apple (Malus sieversii var. kirgizorum), pear (Pyrus korshinskyi Litv.), rosehip (Rosa canina), or barberry (Berberis oblonga). Wild pear, characterised by its high level of alimentary fibres (8.76 g/100 g), offers a promising potential for industrial pectin production. Barberry features higher radical scavenging activity (antioxidant activity) as compared to Iranian and Turkish ecotypes. Among the investigated fruits and berries, barberry and rosehip represent a good source of bioactive phytochemicals due to their high phenolic, anthocyanin, vitamin C and mineral contents. Regular consumption of such wild fruits can contribute between 26 and 100% to the recommended dietary allowance of selected mineral elements (Ca, Zn, Fe, Mn) helping to combat micro-nutrient deficiency in humans.
Guidelines for Perioperative Care for Pancreatoduodenectomy: Enhanced Recovery After Surgery (ERAS) Recommendations 2019
Authors: Melloul Emmanuel , Lassen Kristoffer , Roulin Didier , Grass Fabian , Perinel Julie , Adham Mustapha , Wellge Erik Björn , Kunzler Filipe , Besselink Marc G. , Asbun Horacio , Scott Michael J. , Dejong Cornelis H. C. , Vrochides Dionisos , Aloia Thomas , Izbicki Jakob R. , Demartines Nicolas
Published: March 2020

Background

Enhanced recovery after surgery (ERAS) pathways are now implemented worldwide with strong evidence that adhesion to such protocol reduces medical complications, costs and hospital stay. This concept has been applied for pancreatic surgery since the first published guidelines in 2012. This study presents the updated ERAS recommendations for pancreatoduodenectomy (PD) based on the best available evidence and on expert consensus.

Methods

A systematic literature search was conducted in three databases (Embase, Medline Ovid and Cochrane Library Wiley) for the 27 developed ERAS items. Quality of randomized trials was assessed using the Consolidated Standards of Reporting Trials statement checklist. The level of evidence for each item was determined using the Grading of Recommendations Assessment Development and Evaluation system. The Delphi method was used to validate the final recommendations.

Results

A total of 314 articles were included in the systematic review. Consensus among experts was reached after three rounds. A well‐implemented ERAS protocol with good compliance is associated with a reduction in medical complications and length of hospital stay. The highest level of evidence was available for five items: avoiding hypothermia, use of wound catheters as an alternative to epidural analgesia, antimicrobial and thromboprophylaxis protocols and preoperative nutritional interventions for patients with severe weight loss (> 15%).

Conclusions

The current updated ERAS recommendations for PD are based on the best available evidence and processed by the Delphi method. Prospective studies of high quality are encouraged to confirm the benefit of current updated recommendations.
The importance of Calanus glacialis for the feeding success of young polar cod: a circumpolar synthesis
Authors: Bouchard Caroline , Fortier Louis
Published: March 2020

Understanding the feeding ecology of polar cod (Boreogadus saida) during its first year of life is crucial to forecasting its response to the ongoing borealization of Arctic seas. We investigated the relationships between diet composition and feeding success in 1797 polar cod larvae and juveniles 4.5–55.6 mm standard length (SL) collected in five Arctic seas from 1993 to 2009. Prey were identified to species and developmental stages when possible, measured, and their carbon content was estimated using taxon-specific allometric equations. Feeding success was defined as the ratio of ingested carbon to fish weight. Carbon uptake in polar cod larvae < 15 mm was sourced primarily from calanoid copepods eggs and nauplii which were positively selected from the plankton. With increasing length, carbon sources shifted from eggs and nauplii to the copepodites of Calanus glacialis, Calanus hyperboreus and Pseudocalanus spp. Calanus glacialis copepodites were the main carbon source in polar cod > 25 mm and the only copepodite positively selected for. Pseudocalanus spp. copepodites became important replacement prey when C. glacialis left the epipelagic layer at the end of summer. Calanus glacialis was the preferred prey of polar cod, contributing from 23 to 84% of carbon uptake at any stage in the early development. Feeding success was determined by the number of prey captured in larvae < 15 mm and by the size of prey in juveniles > 30 mm. As Arctic seas warm, the progressive displacement of C. glacialis by the smaller Calanus finmarchicus could accelerate the replacement of polar cod, the dominant Arctic forage fish, by boreal species.
Radiomics for lung adenocarcinoma manifesting as pure ground-glass nodules: invasive prediction
Authors: Sun Yingli , Li Cheng , Jin Liang , Gao Pan , Zhao Wei , Ma Weiling , Tan Mingyu , Wu Weilan , Duan Shaofeng , Shan Yuqing , Li Ming
Published: March 2020

Objectives

To investigate the value of radiomics based on CT imaging in predicting invasive adenocarcinoma manifesting as pure ground-glass nodules (pGGNs).

Methods

This study enrolled 395 pGGNs with histopathology-confirmed benign nodules or adenocarcinoma. A total of 396 radiomic features were extracted from each labeled nodule. A Rad-score was constructed with the least absolute shrinkage and selection operator (LASSO) in the training set. Multivariate logistic regression analysis was conducted to establish the radiographic model and the combined radiographic–radiomics model. The predictive performance was validated by receiver operating characteristic (ROC) curve. Based on the multivariate logistic regression analysis, an individual prediction nomogram was developed and the clinical utility was assessed.

Results

Five radiomic features and four radiographic features were selected for predicting the invasive lesions. The combined radiographic–radiomics model (AUC 0.77; 95% CI, 0.69–0.86) performed better than the radiographic model (AUC 0.71; 95% CI, 0.62–0.81) and Rad-score (AUC 0.72; 95% CI, 0.63–0.81) in the validation set. The clinical utility of the individualized prediction nomogram developed using the Rad-score, margin, spiculation, and size was confirmed in the validation set. The decision curve analysis (DCA) indicated that using a model with Rad-score to predict the invasive lesion would be more beneficial than that without Rad-score and the clinical model.

Conclusions

The proposed radiomics-based nomogram that incorporated the Rad-score, margin, spiculation, and size may be utilized as a noninvasive biomarker for the assessment of invasive prediction in patients with pGGNs.

Key Points

• CT-based radiomics analysis helps invasive prediction manifested as pGGNs.

• The combined radiographic–radiomics model may be utilized as a noninvasive biomarker for predicting invasive lesion for pGGNs.

• Radiomics-based individual nomogram may serve as a vital decision support tool to identify invasive pGGNs, obviating further workup and blind follow-up.
Knowledge-Driven Intelligent Survey Systems Towards Open Science
Authors: Edelstein Elspeth , Pan Jeff Z. , Soares Ricardo , Wyner Adam
Published: March 2020

In this paper, we propose Knowledge Graph (KG), an articulated underlying semantic structure, as a semantic bridge between humans, systems, and scientific knowledge. To illustrate our proposal, we focus on KG-based intelligent survey systems. In state-of-the-art systems, information is hard-coded or implicit, making it hard for researchers to reuse, customise, link, or transmit structured knowledge. Furthermore, such systems do not facilitate dynamic interaction based on semantic structure. We design and implement a knowledge-driven intelligent survey system which is based on knowledge graph, a widely used technology that facilitates sharing and querying hypotheses, survey content, results, and analyses. The approach is developed, implemented, and tested in the field of Linguistics. Syntacticians and morphologists develop theories of grammar of natural languages. To evaluate theories, they seek intuitive grammaticality (well-formedness) judgments from native speakers, which either support hypotheses or provide counter-evidence. Our preliminary experiments show that a knowledge graph-based linguistic survey can provide more nuanced results than the traditional document-based grammaticality judgment surveys by allowing for tagging and manipulation of specific linguistic variables.
Counting Boolean functions with faster points
Authors: Sălăgean Ana , Özbudak Ferruh
Published: March 2020

Duan and Lai introduced the notion of “fast point” for a Boolean function f as being a direction a so that the algebraic degree of the derivative of f in direction a is strictly lower than the expected $$\deg (f)-1$$

deg
(
f
)
-
1

. Their study was motivated by the fact that the existence of fast points makes many cryptographic differential attacks (such as the cube and AIDA attack) more efficient. The number of functions with fast points was determined by Duan et al. in some special cases and by Sălăgean and Mandache-Sălăgean in the general case. We generalise the notion of fast point, defining a fast point of order $$\ell $$
ℓ
as being a fast point a so that the degree of the derivative of f in direction a is lower by at least $$\ell $$
ℓ
than the expected degree. We determine an explicit formula for the number of functions of degree d in n variables which have fast points of order $$\ell $$
ℓ
. Furthermore, we determine the number of functions of degree d in n variables which have a given number of fast points of order $$\ell $$
ℓ
, and also the number of functions which have a given profile in terms of the number of fast points of each order. We apply our results to compute the probability of a function to have fast points of order $$\ell $$
ℓ
. We also compute the number of functions which admit linear structures (i.e. their derivative in a certain direction is constant); such functions have a long history of being used in the analysis of symmetric ciphers.