bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Superior Mesenteric Arterial Occlusion Caused by a Thoracic Aortic Mural Thrombus in a Patient Without Coagulation Disorder or Aortic Disease: A Case Report
Authors: Yoshiya Shohei , Sakano Takahiro , Inokuchi Shoichi , Hirayama Yoshie , Tsuda Yasuo , Taketani Kenji , Kimura Yasue , Minagawa Ryosuke , Koga Tadashi , Kai Masanori , Kajiyama Kiyoshi
Published: May 2018

Introduction

Aortic mural thrombus (AMT) formation in a patient without hypercoagulability and preexisting aortic disease is very rare, and acute superior mesenteric artery (SMA) occlusion resulting from AMT is clinically infrequent.

Case presentation

A 70-year-old woman was transferred to our institute with a diagnosis of acute SMA occlusion. Contrast-enhanced computed tomography (CECT) revealed thromboemboli in the SMA and a thoracic AMT. She immediately underwent angiography and subsequent endovascular aspiration and transcatheter infusion, which recanalized the SMA. However, CECT suggested intestinal ischemia; therefore, she underwent intestinal resection, and we administered anticoagulant therapy with heparin and warfarin postoperatively for the thoracic AMT. Although repeat thrombus formation developed in an ileal branch despite anticoagulant therapy, she had no abdominal symptoms; therefore, we continued the anticoagulant therapy. CECT 3 months later confirmed the absence of thoracic AMT and normal ileal findings.

Conclusion

We report a case of acute SMA occlusion and preceding splenic infarction that resulted from thoracic AMT in a patient without hypercoagulability and preexisting aortic disease. AMT should always be considered as a cause of acute SMA occlusion in patients without heart disease, including atrial fibrillation or severe arteriosclerosis.
Efficacy of Transhepatic Anterior Approach to the Inferior Vena Cava for Malignant Pheochromocytoma Invading Right Posterior Lobe of the Liver: A Case Report
Authors: Tsujio Gen , Kimura Kenjiro , Tauchi Yukie , Ohira Go , Amano Ryosuke , Yamazoe Sadaaki , Nishio Kohei , Onoda Naoyosi , Maeda Kiyoshi , Hirakawa Kosei , Ohira Masaichi
Published: May 2018

Introduction:

The anterior approach to the inferior vena cava (IVC) by the liver hanging maneuver is effective in resecting large retrohepatic tumors without mobilizing the right lobe.

Case presentation:

A 50-year-old man was referred to our hospital with a diagnosis of pheochromocytoma. He had severe congestive heart failure and cardiac ejection fraction was 15%. Abdominal magnetic resonance imaging (MRI) and ultrasonography (US) showed an adrenal mass about 80 mm in diameter. The tumor-infiltrated posterior segment of the right hepatic lobe and tumor were widely attached to the IVC. After treatment of congestive heart failure with conservative therapy, surgery was planned. Right adrenectomy and right hepatectomy were performed, the latter using the liver hanging maneuver to avoid mobilizing the right lobe, and we were able to minimize blood pressure fluctuations and perform the operation safely. The histopathologic diagnosis was malignant pheochromocytoma.

Conclusions:

We performed right hepatectomy without mobilizing the right lobe by the liver hanging maneuver and minimized stimulation of the tumor. We could perform the operation safely using the liver hanging maneuver, which seems effective in such cases.
CSF nonphosphorylated Tau as a biomarker for the discrimination of AD from CJD
Authors: Ermann Natalia , Lewczuk Piotr , Schmitz Matthias , Lange Peter , Knipper Tobias , Goebel Stefan , Kornhuber Johannes , Zerr Inga , Llorens Franc
Published: May 2018

Creutzfeldt–Jakob disease and Alzheimer's disease are characterized by the presence of elevated total‐Tau cerebrospinal fluid concentrations while the presence of hyperphosphorylated Tau forms in the cerebrospinal fluid is rather a hallmark of Alzheimer's disease. Here we aimed to investigate potential contribution of nonphospho‐Tau epitopes (non‐P‐Tau) in the discrimination between both diseases. Non‐P‐Tau cerebrospinal fluid concentration was highly increased in Creutzfeldt–Jakob disease (n = 57, 3683 ± 3599 pg/mL) compared to Alzheimer's disease (n = 41, 148 ± 219 pg/mL) and neurological controls (n = 56, 62 ± 40 pg/mL), and significantly improved the proportion of correctly classified patients (99%) compared to that achieved by total‐Tau (90%), P‐Tau (62%) and 14‐3‐3 (91%).
Giant Piezoelectric Coefficients in Relaxor Piezoelectric Ceramic PNN‐PZT for Vibration Energy Harvesting
Authors: Gao Xiangyu , Wu Jingen , Yu Yang , Chu Zhaoqiang , Shi Huaduo , Dong Shuxiang
Published: May 2018

It is well known that the piezoelectric performance of ferroelectric Pb(Zr,Ti)O3 (PZT) based ceramics is far inferior to that of ferroelectric single crystals due to ceramics' polycrystalline nature. Herein, it is reported that piezoelectric stress coefficient e33 = 39.24 C m−2 (induced electric displacement under applied strain) in the relaxor piezoelectric ceramic 0.55Pb(Ni1/3Nb2/3)O3–0.135PbZrO3–0.315PbTiO3 (PNN‐PZT) prepared by the solid state reaction method exhibits the highest value among various reported ferroelectric ceramic and single crystal materials. In addition, its piezoelectric coefficient d33* = 1753 pm V−1 is also comparable with that of the commercial Pb(Mg1/3Nb2/3)O3‐PbTiO3 (PMN‐PT) piezoelectric single crystal. The PNN‐PZT ceramic is then assembled into a cymbal energy harvester. Notably, its maximum output current at the acceleration of 3.5 g is 2.5 mApp, which is four times of the PMN‐PT single crystal due to the large piezoelectric e33 constants; while the maximum output power is 14.0 mW, which is almost the same as the PMN‐PT single crystal harvester. The theoretical analysis on force‐induced power output is also presented, which indicates PNN‐PZT ceramic has great potential for energy device application.
Advances in Polar Materials for Lithium–Sulfur Batteries
Authors: Wang Hongqiang , Zhang Wenchao , Xu Jianzhong , Guo Zaiping
Published: May 2018

Lithium–sulfur batteries are regarded as promising candidates for energy storage devices due to their high theoretical energy density. Various approaches are proposed to break through the obstacles that are preventing Li–S batteries from realizing practical application. Recently, the importance of the strong chemical interaction between polar materials and polysulfides is recognized by researchers to improve the performance of Li–S batteries, especially with respect to the shuttle effect. Polar materials, unlike nonpolar materials, exhibit strong interactions with polysulfides without any modification or doping because of their intrinsic polarity, absorbing the polar polysulfides and thus suppressing the notorious shuttle effect. The recent advances on polar materials for Li–S batteries are reviewed here, especially the chemical polar–polar interaction effects toward immobilizing dissolved polysulfides, and the relationship between the intrinsic properties of the polar materials and the electrochemical performance of the Li–S batteries are discussed. Polar materials, including polar inorganics in the cathode and polar organics as binder for the Li–S batteries are respectively described. Finally, future directions and prospects for the polar materials used in Li–S batteries are also proposed.
Targeted Nanoparticle‐Mediated Gene Therapy Mimics Oncolytic Virus for Effective Melanoma Treatment
Authors: Luo Li , Yang Yuping , Du Ting , Kang Tianyi , Xiong Meimei , Cheng Hao , Liu Yu , Wu Yujiao , Li Yang , Chen Yuwen , Zhang Qianqian , Liu Xuan , Wei Xiawei , Mi Peng , She Zhigang , Gao Guangping , Wei Yuquan , Gou Maling
Published: May 2018

Oncolytic virus has potential applications in cancer therapy. However, its clinical application is restricted by the virus‐associated biosafety issues. Here, inspired by the key role of vesicular stomatitis virus matrix protein (VSVMP) in the oncolytic vesicular stomatitis virus (VSV) induced apoptosis, a targeted nanoparticle‐delivered neutral VSVMP gene formulation is designed to act like the VSV for cancer therapy. This VSVMP formulation consists of a CRGDKGPDC peptide modified hybrid monomethoxy poly (ethylene glycol)‐poly(d,l‐lactide) nanoparticles complexed with VSVMP plasmid, having good blood compatibility and tumor targeting ability. The transfection efficiency is as high as that of VSV. After intravenous administration, the VSVMP formulation can efficiently target the tumor, significantly inhibit the melanoma growth and metastasis, prolong the survival time of tumor‐bearing mice, and does not cause obvious systemic toxicity. The anticancer mechanisms involve apoptosis induction, angiogenesis inhibition and some virus‐associated signal pathways activation. This work demonstrates a VSV‐inspired nonviral gene therapy that has promising clinical applications in melanoma treatment.
Elastic Fluctuations and Structural Heterogeneities in Metallic Glasses
Authors: Liu Chaoyang , Maaß Robert
Published: May 2018

Suppressing crystallization of a metallic melt results in a disordered solid, also known as a metallic glass. One may conclude that a metallic glass is free of defined structural length scales beyond some atomic‐scale value that characterizes short‐ and medium‐range order. While it is well known from atomistic modeling that a metallic glass is structurally heterogeneous, heterogeneities at such a small length scale can hardly be resolved in experiments. This review highlights experimental insights into elastic fluctuations and structural heterogeneities that emerge at scales between a few nanometers and tens to hundreds of micrometers. It distinguishes between structural and property fluctuations in as‐cast metallic glasses, and heterogeneities introduced by elastic and inhomogeneous plastic deformation. As‐cast glasses reveal elastic fluctuations across 3 orders of magnitude, suggesting a hierarchy of length scales that can be tuned by thermomechanical processing. Similarly, nanoscale strain localization into shear bands drives the formation of structural and elastic heterogeneities at both the nano‐ and the microscale. It is proposed that both types of fluctuations will allow one to quantitatively define structure–property relationships via measurable length scales—an approach that has largely contributed to the engineering success of crystalline metals.
Bioinspired Superwettability Electrospun Micro/Nanofibers and Their Applications
Authors: Hou Lanlan , Wang Nü , Wu Jing , Cui Zhimin , Jiang Lei , Zhao Yong
Published: May 2018

Inspired by the self‐cleaning phenomenon in nature biology, superwettable materials systems have been increasingly studied by multidisciplinary scientists in past two decades. Among various fabrication methods, electrospinning technology, with superior capability of comprehensive coordination of surface chemical composition and hierarchical micro/nanostructures, has been proved to be a versatile method to fabricate diverse fibrous materials with superwettability from polymers, ceramics, to composites. This review first introduces the progress of electrospinning technology in generating various hierarchical structured nanofibers. Then, the wetting theory of liquid on fibers and recent approaches toward fabricating bioinspired electrospun micro/nanofibers with superwettability are described. Based on the special wettability to different liquids, the electrospun nanofibrous materials play significant roles in liquid mixtures separations, water collection, unidirectional liquid penetrations, and in environmentally responsive materials. Finally, the challenges and promising prospects on electrospun superwettability nanofibrous materials are highlighted.
Theoretical and Experimental Insight into the Mechanism for Spontaneous Vertical Growth of ReS2 Nanosheets
Authors: Ghoshal Debjit , Yoshimura Anthony , Gupta Tushar , House Andrew , Basu Swastik , Chen Yanwen , Wang Tianmeng , Yang Yang , Shou Wenjia , Hachtel Jordan A. , Idrobo Juan Carlos , Lu Toh‐Ming , Basuray Sagnik , Meunier Vincent , Shi Su‐Fei , Koratkar Nikhil
Published: May 2018

Rhenium disulfide (ReS2) differs fundamentally from other group‐VI transition metal dichalcogenides (TMDs) due to its low structural symmetry, which results in its optical and electrical anisotropy. Although vertical growth is observed in some TMDs under special growth conditions, vertical growth in ReS2 is very different in that it is highly spontaneous and substrate‐independent. In this study, the mechanism that underpins the thermodynamically favorable vertical growth mode of ReS2 is uncovered. It is found that the governing mechanism for ReS2 growth involves two distinct stages. In the first stage, ReS2 grows parallel to the growth substrate, consistent with conventional TMD growth. However, subsequent vertical growth is nucleated at points on the lattice where Re atoms are “pinched” together. At such sites, an additional Re atom binds with the cluster of pinched Re atoms, leaving an under‐coordinated S atom protruding out of the ReS2 plane. This under‐coordinated S is “reactive” and binds to free Re and S atoms, initiating growth in a direction perpendicular to the ReS2 surface. The utility of such vertical ReS2 arrays in applications where high surface‐to‐volume ratio and electric‐field enhancement are essential, such as surface enhanced Raman spectroscopy, field emission, and solar‐based disinfection of bacteria, is demonstrated.
Ternary Blend Strategy for Achieving High‐Efficiency Organic Solar Cells with Nonfullerene Acceptors Involved
Authors: Liu Xiaoyu , Yan Yajie , Yao Yao , Liang Ziqi
Published: May 2018

Nonfullerene acceptors have recently drawn considerable attention in bulk heterojunction organic solar cells (OSCs). The power conversion efficiency (PCE) over 14% is achieved in single‐junction fullerene‐free OSCs, which has surpassed that of fullerene‐based counterparts. For future commercial applications, however, a high and stable PCE > 15% is required, which entails rational material design and device optimization. In this context, three approaches are generally utilized—the synthesis of novel nonfullerene acceptors and the selection of suitable polymer donors to pair with them, the tandem or multijunction device architecture, and the ternary blend strategy. Compared to the former two methods, the ternary strategy allows to employ the existing photovoltaic materials and the single‐junction device. Therefore, an exploration of nonfullerene acceptor–based ternary blend OSCs (NFTSCs) has shown unprecedented progress since 2016. This review summarizes and classifies the photovoltaic materials utilized in NFTSCs, aiming to not only exhibit the recent development of NFTSCs but also elucidate the correlation among donor/acceptor materials, film morphology, transport dynamics, and device fabrication toward high‐efficiency OSCs. Lastly, the above key advances are highlighted along with the existing issues and insights into the viable path for the further research thrusts are offered.
Over 14% Efficiency in Organic Solar Cells Enabled by Chlorinated Nonfullerene Small‐Molecule Acceptors
Authors: Zhang Hao , Yao Huifeng , Hou Junxian , Zhu Jie , Zhang Jianqi , Li Wanning , Yu Runnan , Gao Bowei , Zhang Shaoqing , Hou Jianhui
Published: May 2018

To make organic solar cells (OSCs) more competitive in the diverse photovoltaic cell technologies, it is very important to demonstrate that OSCs can achieve very good efficiencies and that their cost can be reduced. Here, a pair of nonfullerene small‐molecule acceptors, IT‐2Cl and IT‐4Cl, is designed and synthesized by introducing easy‐synthesis chlorine substituents onto the indacenodithieno[3,2‐b]thiophene units. The unique feature of the large dipole moment of the CCl bond enhances the intermolecular charge‐transfer effect between the donor–acceptor structures, and thus expands the absorption and down shifts the molecular energy levels. Meanwhile, the introduction of CCl also causes more pronounced molecular stacking, which also helps to expand the absorption spectrum. Both of the designed OSCs devices based on two acceptors can deliver a power conversion efficiency (PCE) greater than 13% when blended with a polymer donor with a low‐lying highest occupied molecular orbital level. In addition, since IT‐2Cl and IT‐4Cl have very good compatibility, a ternary OSC device integrating these two acceptors is also fabricated and obtains a PCE greater than 14%. Chlorination demonstrates effective ability in enhancing the device performance and facile synthesis route, which both deserve further exploitation in the modification of photovoltaic materials.
O‐, N‐Atoms‐Coordinated Mn Cofactors within a Graphene Framework as Bioinspired Oxygen Reduction Reaction Electrocatalysts
Authors: Yang Yang , Mao Kaitian , Gao Shiqi , Huang Hao , Xia Guoliang , Lin Zhiyu , Jiang Peng , Wang Changlai , Wang Hui , Chen Qianwang
Published: May 2018

Manganese (Mn) is generally regarded as not being sufficiently active for the oxygen reduction reaction (ORR) compared to other transition metals such as Fe and Co. However, in biology, manganese‐containing enzymes can catalyze oxygen‐evolving reactions efficiently with a relative low onset potential. Here, atomically dispersed O and N atoms coordinated Mn active sites are incorporated within graphene frameworks to emulate both the structure and function of Mn cofactors in heme–copper oxidases superfamily. Unlike previous single‐metal catalysts with general M‐N‐C structures, here, it is proved that a coordinated O atom can also play a significant role in tuning the intrinsic catalytic activities of transition metals. The biomimetic electrocatalyst exhibits superior performance for the ORR and zinc–air batteries under alkaline conditions, which is even better than that of commercial Pt/C. The excellent performance can be ascribed to the abundant atomically dispersed Mn cofactors in the graphene frameworks, confirmed by various characterization methods. Theoretical calculations reveal that the intrinsic catalytic activity of metal Mn can be significantly improved via changing local geometry of nearest coordinated O and N atoms. Especially, graphene frameworks containing the Mn‐N3O1 cofactor demonstrate the fastest ORR kinetics due to the tuning of the d electronic states to a reasonable state.
Exceptional Iodine Capture in 2D Covalent Organic Frameworks
Authors: Wang Ping , Xu Qing , Li Zhongping , Jiang Weiming , Jiang Qiuhong , Jiang Donglin
Published: May 2018

Progress in chemistry over the past four decades has generated a variety of porous materials for removing iodine—a radioactive emission accompanying nuclear fission. However, most studies are still based on the notion that entangled pores together with specific binding sites are essential for iodine capture. Here, an unraveled physical picture of iodine capture that overturns the preconception by exploring 1D channeled porous materials is disclosed. 2D covalent organic frameworks are constructed in a way so that they are free of interpenetration and binding sites but consist of 1D open channels. As verified with different channels shaping from hexagonal to tetragonal and trigonal and ranging from micropores to mesopores, all the 1D channels enable a full access to iodine, generalizing a new paradigm that the pore volume determines the uptake capacity. These results are of fundamental importance to understanding iodine uptake and designing materials to treat coagulative toxic vapors.
Lysine‐Derived Carbon Dots for Chiral Inhibition of Prion Peptide Fibril Assembly
Authors: Arad Elad , Bhunia Susanta Kumar , Jopp Jürgen , Kolusheva Sofiya , Rapaport Hanna , Jelinek Raz
Published: May 2018

The transmissible spongiform encephalopathies are a family of diseases characterized by abnormal folding and aggregation of the prion protein. One of the directions in the search for cure for these and other amyloid diseases focuses on the inhibition of protein aggregation by small molecules, short peptides, and nanoparticles. Nanoparticles seem to be particularly promising therapeutic candidates since they are stable, can be made biocompatible, and might readily traverse physiological barriers such as the blood–brain barrier. Here, a novel class of chiral amyloid inhibitors consisting of carbon quantum dots (C‐dots) that are synthesized from eitherd‐ orl‐lysine (Lys) as the sole carbonaceous building block are reported. The interactions of the chiral lys‐C‐dots with the amyloidogenic determinant of the prion peptide (PrP, 106–126 sequence) in the presence of lipid bilayers appears to be highly stereoselective, with thel‐Lys‐C‐dots being superior to thed‐Lys‐C‐dots in their ability to modulate the structural transformations and aggregation of PrP(106–126). This work provides new insights into chiral effects upon amyloid peptides and opens the way to developing chiral carbon‐based nanostructures as advanced amyloid inhibitors.
Photopharmacology in Alzheimer's Disease
Authors: Rodríguez‐Soacha Diego Alejandro , Decker Michael
Published: May 2018

In this report, the advances of photopharmacology as a method that allows the study of therapeutically relevant target proteins for Alzheimer's disease (AD) with high spatiotemporal resolution through photoswitchable molecules that are manipulated by light irradiation will be presented. The chemical and biophysical basics of the design of photoswitchable drugs are considered, as well as their current specific applications in the development of tool compounds to investigate functions of acetylcholinesterase, muscarinic acetylcholine, cannabinoid, and NMDA receptors, respectively. All of them represent highly important AD targets.
An Analytical Model for the Corrosion Risk of Water Alternating Gas Injection Wells in CO2 Enhanced Oil Recovery
Authors: Wang Zi Ming , Song Guang‐Ling
Published: May 2018

An analytical model is proposed to describe the corrosion risk profile of a well tube in water alternating gas (WAG) CO2 injection conditions based on the assumption that the drying process of the water layer on the inner wall of the well tube plays a crucial role in controlling corrosion. In this model, the fluid properties, the thermodynamic equilibrium of CO2 and water steam, and an empirical CO2 corrosion equation are systematically considered. The description by this model reasonably indicates that fast injection can decrease the corrosion risk and push the highest risk region to a deeper zone, while a longer drying time for a thicker water layer left on the well inner wall can lead to higher corrosion risk. It can also be deduced that the offshore WAG case is more aggressive than the onshore case and some mitigation strategies are suggested for reducing the corrosion risk. These should be helpful for corrosion management and leakage monitoring in the practical WAG CO2 injection.
Nitrogen‐Based Lewis Acids Derived from Phosphonium Diazo Cations
Authors: Waked Alexander E. , Ostadsharif Memar Rouzbeh , Stephan Douglas W.
Published: May 2018

Reaction of PPh3 and [(p‐ClC6H4)N2][BF4] affords [(p‐ClC6H4)N(PPh3)N(PPh3)][BF4] 1, while reaction with (Ph2PCH2)2 gave [(p‐ClC6H4)(NPh2PCH2)2)][BF4] 2. These species confirm the Lewis acidity of [(p‐ClC6H4)N2(PR3)][BF4] cations at N. In contrast, use of bulky phosphines afford the species [ArN2(PR3)][BF4] (R=tBu 3, Mes 4). Compound 3 undergoes one electron reduction to give the stable radical [(p‐ClC6H4)N2(PtBu3)]. 5. Combination of 3 and PtBu3 acts as an FLP to effect (SPh)2 cleavage, generating [PhSPtBu3]+ and the radical [ArN2(PR3)].. Collectively, these data affirm the ability of the cations [ArN2(PR3)]+ to behave as one or two electron acceptors.
Brief Report: Monosodium Urate Monohydrate Crystal Deposits Are Common in Asymptomatic Sons of Patients With Gout: The Sons of Gout Study
Authors: Abhishek Abhishek , Courtney Philip , Jenkins Wendy , Sandoval‐Plata Gabriela , Jones Adrian C. , Zhang Weiya , Doherty Michael
Published: May 2018

Objective

To estimate the prevalence and distribution of asymptomatic monosodium urate monohydrate (MSU) crystal deposition in sons of patients with gout.

Methods

Patients with gout were mailed an explanatory letter with an enclosed postage‐paid study packet to mail to their son(s) age ≥20 years old. Sons interested in participating returned a reply form and underwent telephone screening. Subsequently, they attended a study visit at which blood and urine samples were obtained and musculoskeletal ultrasonography was performed, with the sonographer blinded with regard to the subject's serum urate level. Images were assessed for double contour sign, intraarticular or intratendinous aggregates/tophi, effusion, and power Doppler signal. Logistic regression was used to examine associations. Adjusted odds ratios (ORadj) and 95% confidence intervals (95% CIs) were calculated.

Results

One hundred thirty‐one sons (mean age 43.8 years, mean body mass index 27.1 kg/m2) completed assessments. The serum urate level was ≥6 mg/dl in 64.1%, and 29.8% had either a double contour sign or intraarticular aggregates/tophi in ≥1 joint. All participants with MSU deposition had involvement of 1 or both first metatarsophalangeal joints. Intratendinous aggregates were present in 21.4% and were associated with intraarticular MSU crystal deposits (ORadj 2.96 [95% CI 1.17–7.49]). No participant with a serum urate level of ≤5 mg/dl had MSU crystal deposition seen on ultrasonography, and 24.2% of those with serum urate levels between 5 and 6 mg/dl had ultrasonographic MSU deposition. MSU crystal deposition was associated with increasing serum urate levels (ORadj 1.61 [95% CI 1.10–2.36] for each increase of 1 mg/dl).

Conclusion

Asymptomatic sons of patients with gout frequently have hyperuricemia and MSU crystal deposits. In this study MSU crystal deposits were present in participants with serum urate levels of ≥5 mg/dl. Evaluation of subjects without a family history of gout is needed to determine whether the threshold for MSU crystal deposition is also lower in the general population.
An Organocatalytic Asymmetric Synthesis of Chiral β,β‐Diaryl‐α‐amino Acids via Addition of Azlactones to In Situ Generated para‐Quinone Methides
Authors: Yan Jiyao , Chen Min , Sung Herman H‐Y. , Williams Ian D. , Sun Jianwei
Published: May 2018

An organocatalytic intermolecular C−C bond formation process leading to the efficient synthesis of chiral β,β‐diaryl‐α‐amino acid derivatives is described. In the presence of a suitable chiral phosphoric acid catalyst, a range of para‐hydroxybenzyl alcohols serve as efficient precursors to para‐quinone methides and then react with azlactones in 1,6‐conjugate addition reactions. The asymmetric control has been carefully optimized together with diastereocontrol enabled by identification of the reversible feature of the C−C bond formation and subsequent inhibition by protection of the free hydroxy group in one pot. Compared with previous approaches, including those with pre‐synthesized para‐quinone methides, this protocol provides an alternative and complementary step‐ and pot‐economical approach for the synthesis of chiral β,β‐diaryl‐α‐amino acid derivatives.
Hot Spot Analysis of Water Main Failures in California
Authors: García Diego Martínez , Lee Juneseok , Keck Jonathan , Yang Paul , Guzzetta Robert
Published: May 2018

The objectives of this study were to apply clustering analysis to identify abnormally high concentrations of water main failures (i.e., hot spots) for three selected service areas in California; perform multivariate linear regression for both the three hot spots and all main failures, taking into account pipe materials, diameter, hydraulic pressure, season, soil, length, air temperature, and water content; and compare major differences between the two regression results. Each case study site demonstrated unique failure mechanisms and spatial patterns. Selected pipe materials, season, diameter, and soil type demonstrated statistically significant effects on pipe longevity, accompanied by distinct characteristics for hot spots. This project lays the foundation for a standardized platform and approach to sustainable life cycle assessments for individual water infrastructure elements.
Automated brain extraction and immersive exploration of its layers in virtual reality for the rhesus macaque MRI data sets
Authors: Luo Yanlin , Gao Bin , Deng Yiyi , Zhu Xiaoming , Jiang Tianzi , Zhao Xudong , Yang Zhengyi
Published: May 2018

As we know, the rhesus macaque as a nonhuman primate is quite similar to a human being in genetics. Moreover, it has become essential in animal model anatomy and physiology in many modern medicine research such as the cardiovascular and cerebrovascular diseases in the recent years. This paper describes a pipeline from the raw rhesus macaque brain magnetic resonance imaging data to intuitive 3D inspection of its layers. Brain extraction is an initial step for subsequent analyses, but most of the existing methods so far are designed for human brain, which does not work well with the rhesus macaque. Firstly, we propose a reliable and efficient method to extract the brain from magnetic resonance imaging data sets based on dividing the brain into blocks. Then, we design a trapezoid opacity transfer function based on Compute Unified Device Architecture (CUDA)‐based real‐time volume ray casting, which is dedicated to volume rendering to make the inspection more intuitive. Besides, for an immersive exploration in virtual reality benefits understanding the volumetric data sets, so we also design a layer filter for the segmented rhesus macaque brain data sets, which facilitates the inspection of the interior in Region of Interest (ROI) by an intuitive bimanual interaction via a Leap Motion sensor. Our experiments prove usability and efficiency.
Synthesis of Mesoporous ZIF‐8 Nanoribbons and their Conversion into Carbon Nanoribbons for High‐Performance Supercapacitors
Authors: Yang Xueqing , Chen Wei , Bian Haidong , Sun Tianying , Du Yangyang , Zhang Zhenyu , Zhang Wenjun , Li Yangyang , Chen Xianfeng , Wang Feng
Published: May 2018

ZIF‐8 nanoribbons, with tunable morphology and pore structure, were synthesized by using the tri‐block co‐polymer Pluronic F127 as a soft template. The as‐synthesized ZIF‐8 nanoribbons were converted into carbon nanoribbons by thermal transformation with largely preserved morphology and porosity. The resulting carbon nanoribbons feature both micro‐ and meso‐pores with high surface areas of over 1000 m2 g−1. In addition, nitrogen‐doping in the carbon nanoribbons was achieved, as confirmed by XPS and EELS measurements. The hybrid carbon nanoribbons provide pseudo‐capacitance that promotes electrochemical performance, rendering a high specific capacitance of up to 297 F g−1 at a current density of 0.5 A g−1 in a three‐electrode system. A long cycle life was also demonstrated by recording a 90.26 % preservation of capacitance after 10 000 cycles of charge–discharge at a current density of 4.0 A g−1. Furthermore, a symmetrical supercapacitor is fabricated by employing the carbon nanoribbons, which shows good electrochemical performance with respect to energy, power and cycle life.
Optically Active Polyoxometalate‐Based Silica Nanohelices: Induced Chirality from Inorganic Nanohelices to Achiral POM Clusters
Authors: Attoui Mariam , Pouget Emilie , Oda Reiko , Talaga David , Le Bourdon Gwénaëlle , Buffeteau Thierry , Nlate Sylvain
Published: May 2018

In order to investigate the principle of chiral induction from nanometric silica helices to polyoxometalate (POM) clusters, a series of optically active silica POM‐based nanohelices (NANOPOMs) have been prepared by electrostatic grafting and direct adsorption of α‐Keggin polyoxometalate [α‐PW12O40]3− to well‐defined left‐ and right‐handed silica nanohelices. UV/Vis, Raman, DRIFT, TEM, HR‐TEM, EDS and circular dichroism (CD) spectroscopy were used to characterize these NANOPOMs, and confirm the presence of POM clusters as well as their interactions with the helical support. The optical activity of the left‐handed and right‐handed NANOPOMs has been proven by CD spectroscopy. Their CD spectra are mirror images of one another, showing cotton effects at around 214 and 276 nm, this last contribution corresponding to the oxygen‐to‐tungsten charge‐transfer bands of Keggin polyoxoanions. The CD signal of POM clusters is strongly enhanced for NANOPOMs built by adsorption of POM onto silica nanohelices, indicating a better induced optical activity to POM clusters. These nanohelices are stable, recoverable and active catalysts in the oxidation of sulfides. To the best of our knowledge, the present research represents the first examples of optically active POM‐containing silica nanohelices in which achiral POM clusters have been grafted onto silica nanohelices, and display chiroptical effects.
Effect of N‐Alkyl Substituents on the Hierarchical Self‐Assembly of β‐Cyclodextrin‐Linked Pyrene‐Pyromellitic Diimide Charge‐Transfer Complexes
Authors: Krishnan Sumesh Babu , Krishnan Retheesh , Gopidas Karical Raman
Published: May 2018

Hierarchical self‐assemblies of β‐cyclodextrin‐linked pyrene and N‐alkyl derivatives of pyromellitic diimides are studied in detail. The charge‐transfer interaction between pyrene and pyromellitic diimide is augmented by β‐cyclodextrin–pyromellitic diimide binding interactions in these cases. When the alkyl group is adamantyl, a 1:1 complex was formed with a very high association constant (Ka=1.82×106 m−1). Here, the charge‐transfer interaction is reinforced by inclusion binding of the adamantyl group in the β‐cyclodextrin cavity leading to the formation of 2D sheets, which undergo twisting to give twisted fibres. When the alkyl group is tert‐butyl, a 1:2 complex was formed with a high association constant (Ka=2.91×104 m−1). A detailed analysis showed that the tert‐butyl pyromellitic diimide undergoes both inclusion and rim‐binding interactions with the β‐cyclodextrin. The charge‐transfer complex further self‐assembled into chiral nanostructures as evident from SEM, TEM and AFM analysis. In the case of N‐methyl‐substituted pyromellitic diimide, the interaction with β‐cyclodextrin‐linked pyrene was only through rim binding, which resulted in the formation of a weak charge‐transfer complex with Ka=4.2×103 m−1. Formation of a hierarchical assembly was not observed in this case. A rational mechanism for the self‐assembly, which relies on the strength of the cyclodextrin–pyromellitic diimide complexation is presented.
Unveiling the Binding Modes of the Crystallophore, a Terbium‐based Nucleating and Phasing Molecular Agent for Protein Crystallography
Authors: Engilberge Sylvain , Riobé François , Wagner Tristan , Di Pietro Sebastiano , Breyton Cécile , Franzetti Bruno , Shima Seigo , Girard Eric , Dumont Elise , Maury Olivier
Published: May 2018

Crystallophores are lanthanide complexes that act as powerful auxiliary for protein crystallography due to their strong nucleating and phasing effects. To get first insights on the mechanisms behind nucleation induced by Crystallophore, we systematically identified various elaborated networks of supramolecular interactions between Tb‐Xo4 and subset of 6 protein structures determined by X‐ray diffraction in complex with terbium–Crystallophore (Tb‐Xo4). Such interaction mapping analyses demonstrate the versatile binding behavior of the Crystallophore and pave the way to a better understanding of its unique properties.
Efficient Synthesis of a NHC‐Coordinated Trisilacyclopropylidene and Its Coordination Behavior
Authors: Guddorf Benedikt J. , Hepp Alexander , Lips Felicitas
Published: May 2018

With a co‐reduction procedure using 2 equivalents Mes2SiCl2 and 1 equivalent NHCiPr2Me2→SiCl4 an NHC‐adduct of a trisilacyclopropylidene (SiMes2)2SiNHCiPr2Me2 1 was synthesized. Addition of NHCMe4 to 1 results in quantitative carbene exchange under release of NHCiPr2Me2 to yield (SiMes2)2SiNHCMe4 2. Both NHC‐coordinated trisilacyclopropylidenes coordinate to BH3. In reaction of 1 with SiMe3N3 a NHC‐coordinated trisilane with an exocyclic Si=N double bond is formed. With diphenylacetylene 1 undergoes a ring expansion at room temperature to afford a five‐membered ring compound with an NHC‐coordinated silylene functionality.
Proactive content caching by exploiting transfer learning for mobile edge computing
Authors: Hou Tingting , Feng Gang , Qin Shuang , Jiang Wei
Published: May 2018

To address the vast multimedia traffic volume and requirements of user quality of experience in the next‐generation mobile communication system (5G), it is imperative to develop efficient content caching strategy at mobile network edges, which is deemed as a key technique for 5G. Recent advances in edge/cloud computing and machine learning facilitate efficient content caching for 5G, where mobile edge computing can be exploited to reduce service latency by equipping computation and storage capacity at the edge network. In this paper, we propose a proactive caching mechanism named learning‐based cooperative caching (LECC) strategy based on mobile edge computing architecture to reduce transmission cost while improving user quality of experience for future mobile networks. In LECC, we exploit a transfer learning‐based approach for estimating content popularity and then formulate the proactive caching optimization model. As the optimization problem is NP‐hard, we resort to a greedy algorithm for solving the cache content placement problem. Performance evaluation reveals that LECC can apparently improve content cache hit rate and decrease content delivery latency and transmission cost in comparison with known existing caching strategies.
Unexplained absence resulting in deaths of nursing home residents in Australia—A 13‐year retrospective study
Authors: Woolford Marta H. , Bugeja Lyndal , Weller Carolina , Johnson Marilyn , Chong Derek , Ibrahim Joseph E.
Published: May 2018

Objectives

To examine deaths of Australian nursing home (NH) residents following an unexplained absence.

Methods

Population based cross‐sectional study was conducted using coronial data from the National Coronial Information System. Participants are residents of accredited NHs if death followed an unexplained absence and was reported to the Coroner between July 1, 2000 and June 30, 2013. Individual, organisational, environmental, and unexplained absence event factors were extracted from coronial records. Data were analysed using descriptive statistics.

Results

Of 21 672 NH deaths, 24 (0.1%) followed an unexplained absence. This comprised 17 unintentional external (injury‐related) causes and 7 natural cause deaths. Drowning was the most frequent external cause of death (59%, n = 10). Deaths occurred more frequently in males (83.3%, n = 20), and in the age group 85‐94 years (37.5%, n = 9). The majority of NH residents, for whom data were available (n = 15), had a diagnosis of dementia (86.7%, n = 13). Most residents were found in waterways (41.7%, n = 10). Median distance travelled was 0.5 km (IQR: 0.25‐2.4 km), with almost 70% of residents found within 1.0 km of their NH. Most residents left the NH by foot (88.2%, n = 15). Half of the residents were found within 6 hours of time last seen (median: 6 hours, 40 minutes; IQR: 6.0‐11.45 hours).

Conclusion

Unexplained absences in elderly NH residents are a relatively common event. This study provides valuable information for aged care providers, governments, and search and rescue teams, and should contribute to debates about balancing issues of safety with independence.
In the Balance: Weighing Preferences of Decisionally Incapacitated Patients
Authors: Guidry‐Grimes Laura
Published: May 2018

In this issue of the Hastings Center Report, Jason Wasserman and Mark Navin argue that patients without decisional capacity can still have relatively stable wishes or inclinations toward one treatment option over another and that these preferences are “not devoid of moral weight and might therefore guide or at least influence treatment decisions when they cannot be defeated by other considerations.” This position is not controversial among most bioethicists. The hard work comes in sussing out the details of this position. How much moral weight do these preferences have? When should preferences be defeated by other considerations? How should we identify actual preferences, and how should preferences be differentiated and weighed against one another?
Comparison of illumination geometry for lifetime‐based measurements in whole‐body preclinical imaging
Authors: Sinsuebphon Nattawut , Rudkouskaya Alena , Barroso Margarida , Intes Xavier
Published: May 2018

Macroscopic fluorescence lifetime imaging (MFLI) has been proved to be an accurate tool to quantify Förster resonance energy transfer (FRET) lifetime‐based assessment of receptor‐ligand engagement in vitro and in vivo. Herein, we report on the quantitative comparison of MFLI for whole‐body preclinical studies in transmittance and reflectance geometries. The comparative study was conducted for both in vitro and in vivo conditions. FRET quantification performance in both geometries was similar in high fluorescence concentration samples. However, the reflectance geometry performed better at low fluorescence concentration. In addition, reflectance geometry could acquire subsurface imaging of the main whole‐body organs of small animals without being compromised by tissue attenuation.
A new variable interval schedule with constant hazard rate and finite time range
Authors: Bugallo Mehdi , Machado Armando , Vasconcelos Marco
Published: May 2018

We propose a new variable interval (VI) schedule that achieves constant probability of reinforcement in time while using a bounded range of intervals. By sampling each trial duration from a uniform distribution ranging from 0 to 2 T seconds, and then applying a reinforcement rule that depends linearly on trial duration, the schedule alternates reinforced and unreinforced trials, each less than 2 T seconds, while preserving a constant hazard function.
Elemental image array generation method by using optimized depth image‐based rendering algorithm for integral imaging display
Authors: Xiao Fei , Xiong Zhao‐Long , Deng Huan , Xing Yan , Wang Qiong‐Hua
Published: May 2018

We propose an elemental image array (EIA) generation method by using an optimized depth image‐based rendering (DIBR) algorithm. In this method, the EIA is synthesized by the reference and virtual viewpoint elemental images, and the virtual viewpoint elemental images at the given locations are generated by DIBR algorithm. We optimize the existing DIBR algorithm by adaptively repairing the warped depth images in the processing part and extend the generation dimension of the virtual viewpoint elemental images from one dimension to two dimensions. The optimized DIBR algorithm can effectively solve the problem: the low quality of virtual viewpoint elemental images caused by discontinuous depth values and disocclusion regions. We also implement the generations of virtual viewpoint elemental images and EIA in graph processing unit to reduce the time cost. Experimental results show that the proposed method can not only improve the quality of the virtual viewpoint images but also accelerate the generations of the virtual viewpoint elemental images and EIA.
Cholesterol Modification of an Anticancer Drug for Efficient Incorporation into a Supramolecular Hydrogel System
Authors: Bakker Maarten H. , Grillaud Maxime , Wu Dan Jing , Fransen Peter‐Paul K. H. , de Hingh Ignace H. , Dankers Patricia Y. W.
Published: May 2018

Treatment of cancer in the peritoneal cavity may be improved with macroscale drug delivery systems that offer control over intraperitoneal concentration of chemotherapeutic agents. Currently, suitable drug carriers to facilitate a sustained release of small hydrophilic drugs such as mitomycin C are lacking. For this purpose, a pH‐responsive supramolecular hydrogel based on ureido‐pyrimidinone (UPy) chemistry is utilized here. In order to provide a sustained release profile, a lipophilicity‐increasing cholesterol conjugation strategy is proposed that enhances affinity between the modified drug (mitomycin‐PEG24‐cholesterol, MPC) and the hydrophobic compartments in the UPy gel. Additional advantages of cholesterol conjugation include improved chemical stability and potency of mitomycin C. In vitro the tunability of the system to obtain optimal effective concentrations over time is demonstrated with a combinatorial treatment of mitomycin C and MPC in one UPy hydrogel delivery system.
Organic Arsenicals as Functional Motifs in Polymer and Biomaterials Science
Authors: Tanaka Joji , Davis Thomas P. , Wilson Paul
Published: May 2018

Arsenic (As) exhibits diverse (bio)chemical reactivity and biological activity depending upon its oxidation state. However, this distinctive reactivity has been largely overlooked across many fields owing to concerns regarding the toxicity of arsenic. Recently, a clinical renaissance in the use of arsenicals, including organic arsenicals that are known to be less toxic than inorganic arsenicals, alludes to the possibility of broader acceptance and application in the field of polymer and biomaterials science. Here, current examples of polymeric/macromolecular arsenicals are reported to stimulate interest and highlight their potential as a novel platform for functional, responsive, and bioactive materials.
A coupled 3‐dimensional bonded discrete element and lattice Boltzmann method for fluid‐solid coupling in cohesive geomaterials
Authors: Wang Min , Feng Y.T. , Pande G.N. , Zhao T.T.
Published: May 2018

This paper presents a 3D bonded discrete element and lattice Boltzmann method for resolving the fluid‐solid interaction involving complicated fluid‐particle coupling in geomaterials. In the coupled technique, the solid material is treated as an assembly of bonded and/or granular particles. A bond model accounting for strain softening in normal contact is incorporated into the discrete element method to simulate the mechanical behaviour of geomaterials, whilst the fluid flow is solved by the lattice Boltzmann method based on kinetic theory and statistical mechanics. To provide a bridge between theory and application, a 3D algorithm of immersed moving boundary scheme was proposed for resolving fluid‐particle interaction. To demonstrate the applicability and accuracy of this coupled method, a benchmark called quicksand, in which particles become fluidised under the driving of upward fluid flow, is first carried out. The critical hydraulic gradient obtained from the numerical results matches the theoretical value. Then, numerical investigation of the performance of granular filters generated according to the well‐acknowledged design criteria is given. It is found that the proposed 3D technique is promising, and the instantaneous migration of the protected soils can be readily observed. Numerical results prove that the filters which comply with the design criteria can effectively alleviate or eliminate the appearance of particle erosion in dams.
On vertical dynamic stability and cross‐section optimization of closed‐ended hollow pile by considering soil compaction effects
Authors: Hu Wentao , Wang Ning , Xu Changjie , Yuan Feng , Jin Zijie
Published: May 2018

This paper conducts a comprehensive study on the effects of expansion force after pile driving on the vertical vibration of the hollow pile. The initial radially inhomogeneous strain field of soil in disturbed soil region and dynamic shear modulus of remolded soil are constructed by applying the cylindrical cavity expansion method. The equation governing the incremental motion of the soil is consequently deduced on the basis of incremental deformations superposed on an underlying finite deformation. The longitudinal impedance of the top of the pile and the velocity response in frequency and time domains are also numerically studied. The relations between the expansion force after pile driving and the velocity response of the pile with different wall thickness are discussed accordingly. The results suggest that a pile has a better dynamical stability when the characteristics of the section are optimized and interacting force with soil medium gets smaller.