bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic Semiconducting Agents for Deep‐Tissue Molecular Imaging: Second Near‐Infrared Fluorescence, Self‐Luminescence, and Photoacoustics
Authors: Miao Qingqing , Pu Kanyi 
Published: July 2018

AbstractOptical imaging has played a pivotal role in biology and medicine, but it faces challenges of relatively low tissue penetration and poor signal‐to‐background ratio due to light scattering and tissue autofluorescence. To overcome these issues, second near‐infrared fluorescence, self‐luminescence, and photoacoustic imaging have recently emerged, which utilize an optical region with reduced light–tissue interactions, eliminate real‐time light excitation, and detect acoustic signals with negligible attenuation, respectively. Because there are only a few endogenous molecules absorbing or emitting above the visible region, development of contrast agents is essential for those deep‐tissue optical imaging modalities. Organic semiconducting agents with π‐conjugated frameworks can be synthesized to meet different optical imaging requirements due to their easy chemical modification and legible structure–property relation. Herein, the deep‐tissue optical imaging applications of organic semiconducting agents including small‐molecule agents and nanoparticle derivatives are summarized. In particular, the molecular engineering and nanoformulation approaches to further improve the tissue penetration and detection sensitivity of these optical imaging modalities are highlighted. Finally, current challenges and potential opportunities in this emerging subfield of biomedical imaging are discussed.
Defect Engineering toward Highly Efficient and Stable Perovskite Solar Cells
Authors: Li Bowei , Ferguson Victoria , Silva S. Ravi P. , Zhang Wei 
Published: July 2018

AbstractMetal halide perovskite solar cells are emerging candidates amongst the next‐generation thin‐film photovoltaic devices with extremely low fabrication cost and high power conversion efficiency. Defects (both in the bulk material and at the interfaces) are recognized as one of the most fundamental reasons for the compromised device performance and long‐term stability of perovskite solar cells. In this review article, the authors analyze the possible origins of the defects formation in metal halide perovskites, followed by the rationalization of various approaches being utilized to reduce the density of defects. The authors demonstrate that defect engineering, including adding dopants in the precursor solutions, interface passivation, or other physical treatments (thermal or light stress), is an essential way to further boost the device performance and enhance their long‐term stability. The authors note that although the exact mechanisms of defect elimination in some approaches are yet to be elucidated, the research on defect engineering is expected to have enormous impact on next wave of device performance optimization of metal halide perovskite solar cells toward Shockley–Queisser limit.
Imaging Electric and Magnetic Modes and Their Hybridization in Single and Dimer AlGaAs Nanoantennas
Authors: McPolin Cillian P. T. , Marino Giuseppe , Krasavin Alexey V. , Gili Valerio , Carletti Luca , De Angelis Costantino , Leo Giuseppe , Zayats Anatoly V. 
Published: July 2018

AbstractAll‐dielectric nanoantennas enable the manipulation and confinement of light on the nanoscale through a variety of resonant excitations. Understanding and controlling the interactions among resonances at a level of individual nanoantennas is required for the development of appropriate design rules for their applications, especially with regard to nonlinear optics, where the nonlinear interaction depends on the resonant behavior in a superlinear manner. Here, cathodoluminescence imaging spectroscopy is used to experimentally investigate the electric and magnetic modes supported by single AlGaAs nanoantennas and their hybridization in a dimer configuration. An interplay is shown between the resonant modes of the nanostructures and interband emission of the semiconductor material, which contrasts with Si nanoantennas, where the bandgap effects are not significant. The measurements are in very good agreement with numerical simulations, which also provided further insight into the nature of the modes. The resonant modes of semiconductor nanoantennas are important for engineering linear and nonlinear metasurfaces, as well as for sensing applications and fluorescence control in nanophotonic environments.
Phase Behavior of Block Copolymer Nanocomposite Systems
Authors: Diaz Javier , Pinna Marco , Zvelindovsky Andrei V. , Pagonabarraga Ignacio 
Published: July 2018

AbstractNanocomposite materials made of block copolymer (BCP) and nanoparticles display properties which can be different from the purely polymeric matrix. The resulting material is a crossover of the original properties of the BCP and the presence of the assembled nanoparticles. A mesoscopic study using cell dynamic simulations is reported, to quantitatively describe the structural properties of such hybrid materials. The most relevant parameters are identified to be the fraction of nanoparticles in the system and its chemical affinity, while the nanoparticle size with respect to the BCP length scales plays a role in the assembly. The morphological phase diagram of the BCP is constructed for nanoparticles with chemical affinity ranging from A‐compatible to B‐compatible for a symmetric A‐B diblock copolymer. Block‐compatible nanoparticles are found to induce a phase transition due to changes in the effective concentration of the hosting phase, while interface‐compatible particles induce the appearance of two new phases due to the saturation of the diblock copolymer interface.
In Situ “Chainmail Catalyst” Assembly in Low‐Tortuosity, Hierarchical Carbon Frameworks for Efficient and Stable Hydrogen Generation
Authors: Li Yiju , Gao Tingting , Yao Yonggang , Liu Zhenyu , Kuang Yudi , Chen Chaoji , Song Jianwei , Xu Shaomao , Hitz Emily M. , Liu Boyang , Jacob Rohit J. , Zachariah Michael R. , Wang Guofeng , Hu Liangbing 
Published: July 2018

AbstractThe chainmail catalysts (transition metals or metal alloys encapsulated in carbon) are regarded as stable and efficient electrocatalysts for hydrogen generation. However, the fabrication of chainmail catalysts usually involves complex chemical vapor deposition (CVD) or prolonged calcination in a furnace, and the slurry‐based electrode assembly of the chainmail catalysts often suffers from inferior mass transfer and an underutilized active surface. In this work, a freestanding wood‐based open carbon framework is designed embedded with nitrogen (N) doped, few‐graphene‐layer‐encapsulated nickel iron (NiFe) alloy nanoparticles (N‐C‐NiFe). 3D wood‐derived carbon framework with numerous open and low‐tortuosity lumens, which are decorated with carbon nanotubes (CNTs) “villi”, can facilitate electrolyte permeation and hydrogen gas removal. The chainmail catalysts of the N‐C‐NiFe are uniformly in situ assembled on the CNT “villi” using a rapid heat shock treatment. The high heating and quenching rates of the heat shock method lead to formation of the well‐dispersed ultrafine nanoparticles. The self‐supported wood‐based carbon framework decorated with the chainmail catalyst displays high electrocatalytic activity and superior cycling durability for hydrogen evolution. The unique heat shock method offers a promising strategy to rapidly synthesize well‐dispersed binary and polynary metallic nanoparticles in porous matrices for high‐efficiency electrochemical energy storage and conversion.
Palladium/Copper Co‐Catalyzed Cascade Metallo‐ene/Sonogashira Coupling Reaction of Allenamides
Authors: Liang Hanbing , Meng Long , Chi Xiaochen , Yao Shuzhi , Chen Hongshuai , Jiao Luyang , Liu Qing , Zhang Daopeng , Liu Hui , Dong Yunhui 
Published: July 2018

AbstractA mild and efficient type of Pd/Cu‐catalyzed allenamide allyl acetate reaction with terminal alkynes affording polyfunctionalized 2,3‐dihydropyrrole derivatives is reported. Allenamide substrates went through two π‐allyl palladium complex processes, and then it was trapped by terminal alkynes on the distal position via a Sonogashira reaction. Two new Csp3−Csp2 and Csp3−Csp bonds were efficiently constructed in one pot.
Environmental enrichment and mouse models: Current perspectives
Authors: Bayne Kathryn 
Published: July 2018

AbstractThe provision of environmental enrichment to numerous species of laboratory animals is generally considered routine husbandry. However, mouse enrichment has proven to be very complex due to the often contradictory outcomes (animal health and welfare, variability in scientific data, etc.) associated with strain, age of the animal when enrichment is provided, gender of the animal, scientific use of the animal, and other housing attributes. While this has led to some suggesting that mice should not be provided enrichment, more recently opinion is trending toward acknowledging that enrichment actually normalizes the animal and data obtained from a mouse living in a barren environment are likely not to be representative or even reliable. This article offers an overview of the types of impact enrichment can have on various strains of mice and demonstrates that enrichment not only has a role in mouse husbandry, but also can lead to new areas of scientific enquiry in a number of different fields.
AMPK promotes the survival of colorectal cancer stem cells
Authors: Guo Bing , Han Xin , Tkach Diane , Huang Shu‐Guang , Zhang Dong 
Published: July 2018

AbstractBackgroundColorectal cancer (CRC) is the third most commonly diagnosed cancer in males and the second in females worldwide in 2012. In the past 20 years, strong evidence suggests that cancer stem cells are the main culprit of cancer metastasis, chemotherapy resistance, and relapse.MethodsTo further understand the unique biological properties of cancer stem cells and uncover novel molecular targets to eradicate them, we first established a panel of patient‐derived xenograft (PDX) tumor models using tumors surgically removed from human colorectal cancer patients. We then isolated CRC cancer stem cells based on their ALDH activity using fluorescent‐activated cell sorting (FACS) and characterized their metabolic properties.ResultsInterestingly, we found that the CRC cancer stem cells (ie, CRC cells with higher ALDH activity, or ALDH+) express higher level of antioxidant genes and have lower level of reactive oxygen species (ROS) than non‐CRC cancer stem cells (ie, CRC cells with lower ALDH activity, or ALDH−). The CRC cancer stem cells also possess more mitochondria mass and show higher mitochondrial activity. More intriguingly, we observed higher AMP‐activated protein kinase (AMPK) activities in these CRC cancer stem cells. Inhibition of the AMPK activity using 2 AMPK inhibitors, Compound C and Iodotubercidin, preferentially induces cell death in CRC cancer stem cells.ConclusionWe propose that AMPK inhibitors may help to eradicate the CRC cancer stem cells and prevent the relapse of CRCs.
The battle against SARS and MERS coronaviruses: Reservoirs and Animal Models
Authors: Gong Shu‐ran , Bao Lin‐lin 
Published: July 2018

AbstractIn humans, infection with the coronavirus, especially the severe acute respiratory syndrome coronavirus (SARS‐CoV) and the emerging Middle East respiratory syndrome coronavirus (MERS‐CoV), induces acute respiratory failure, resulting in high mortality. Irregular coronavirus related epidemics indicate that the evolutionary origins of these two pathogens need to be identified urgently and there are still questions related to suitable laboratory animal models. Thus, in this review we aim to highlight key discoveries concerning the animal origin of the virus and summarize and compare current animal models.
Safety considerations for working with animal models involving human health hazards
Authors: Carpenter Calvin B. 
Published: July 2018

AbstractA human health hazard may constitute a variety of hazards that are encountered in an animal facility. Health hazards include physical, chemical, radioactive, or biological hazards such as cage and rack washers, chemicals used for cleaning and disinfection, experimental drugs or biologics, radioactive isotopes, zoonotic diseases, allergens, experimental infectious agents, or biological toxins. This article will focus on experimental infectious agents and biological toxins (biohazards) that are hazardous to both animals and humans and require biological containment (biocontainment) to prevent their inadvertent release into the environment. Key areas for safely managing a biocontainment animal care and use program and vivarium are described. While scientific research involving health hazards has created some challenges, it has also provided some excellent advances in methods and technologies. The ideas and approaches in this article will be useful for those just entering this field of research and those who have committed their careers to the safe use of animals exposed to biohazards.
Chemistry for Positron Emission Tomography: Recent Advances in 11C‐, 18F‐, 13N‐, and 15O‐Labeling Reactions
Authors: Deng Xiaoyun , Rong Jian , Wang Lu , Vasdev Neil , Zhang Lei , Josephson Lee , Liang Steven H. 
Published: July 2018

AbstractPositron emission tomography (PET) is a molecular imaging technology that provides quantitative information about function and metabolism in biological processes in vivo for disease diagnosis and therapy assessment. The broad application and rapid advances of PET has led to an increased demand for new radiochemical methods to synthesize highly specific molecules bearing positron‐emitting radionuclides. This Review provides an overview of commonly used labeling reactions through examples of clinically relevant PET tracers and highlights the most recent developments and breakthroughs over the past decade, with a focus on 11C, 18F, 13N, and 15O.
Highly Chemo‐ and Stereoselective Catalyst‐Controlled Allylic C−H Insertion and Cyclopropanation Using Donor/Donor Carbenes
Authors: Zhu Dong , Chen Lianfen , Zhang He , Ma Zhiqiang , Jiang Huanfeng , Zhu Shifa 
Published: July 2018

AbstractThe highly chemo‐, enantio‐, and diastereoselective catalyst‐controlled intramolecular allylic C−H insertion and cyclopropanation of donor/donor carbenes are reported. The RuII/Pybox complex selectively catalyzed the intramolecular allylic C−H insertion, providing vinyl‐substituted dihydroindoles with greater than 20:1 chemoselectivity and up to greater than 99 % ee. Chiral dirhodium(II) tetracarboxylates, however, selectively promoted the intramolecular cyclopropanation, giving rise to cyclopropane‐fused tetrahydroquinoline derivatives in excellent yields with greater than 99:1 chemoselectivity and up to 97 % ee.
Testing predictions for symmetry, variability and chronology of backed artefact production in Australia's Western Desert
Authors: MCDONALD JO , REYNEN WENDY , FULLAGAR RICHARD 
Published: July 2018

ABSTRACTThe “Backed Artefact Symmetry Index” (BASI) provides a measure with which to describe geometric variation in Australian backed artefacts, and Peter Hiscock has suggested that desert versions of this artefact type will be more symmetrical than their coastal counterparts. The re‐excavated Serpent's Glen (Karnatukul) site and nearby site of Wirrili have produced a large assemblage of backed artefacts. These Western Desert assemblages allow for the testing of BASI. The backed artefacts demonstrate significantly more variability than predicted, demonstrating that all technological debates benefit from larger well‐dated assemblages. The signalling information observed in these sites’ pigment art repertoires, combined with this versatility in the toolkits, increases our understanding of the complexity of middle and late Holocene highly mobile foragers in the Australian arid zone.
Generalized prediction intervals for treatment effects in random‐effects models
Authors: Al‐Sarraj Razaw , von Brömssen Claudia , Forkman Johannes 
Published: July 2018

AbstractThis article derives generalized prediction intervals for random effects in linear random‐effects models. For balanced and unbalanced data in two‐way layouts, models are considered with and without interaction. Coverage of the proposed generalized prediction intervals was estimated in a simulation study based on an agricultural field experiment. Generalized prediction intervals were compared with prediction intervals based on the restricted maximum likelihood (REML) procedure and the approximate methods of Satterthwaite and Kenward and Roger. The simulation study showed that coverage of generalized prediction intervals was closer to the nominal level 0.95 than coverage of prediction intervals based on the REML procedure.
Late recovery from unconsciousness in a patient with severe posterior reversible encephalopathy syndrome
Authors: Ogura Shiori , Narumiya Hiromichi , Iiduka Ryoji , Nagakane Yoshinari 
Published: July 2018

Key Clinical MessageThis study describes a patient case presenting with severe posterior reversible encephalopathy syndrome (PRES) who needed 3 months to recover impaired consciousness. We discuss the protracted time course needed to deal with severe PRES cases. Positive prognoses can emerge from these situations if treatment is prompt and precise.
Efficient N‐Heterocyclic Carbene/Ruthenium Catalytic Systems for the Alcohol Amidation with Amines: Involvement of Poly‐Carbene Complexes?
Authors: Cheng Hua , Xiong Mao‐Qian , Zhang Ni , Wang Hua‐Jing , Miao Yang , Su Wei , Yuan Ye , Chen Cheng , Verpoort Francis 
Published: July 2018

AbstractThe atom‐economic direct amidation of alcohols with amines has been recently highlighted as an attractive and promising transformation. Among the versatile reported catalytic systems, in situ generated N‐heterocyclic carbene (NHC)/ruthenium (Ru) catalytic systems have demonstrated their advantages such as easy operation and use of commercial Ru compounds. However, the existing catalyst loadings are relatively high, and additional insights for the in situ catalyst generation are still not well‐documented. In this work, a variety of benzimidazole‐based NHC precursors were initially synthesized. Through the screening of various NHC precursors and other reaction conditions, active in situ catalytic systems were discovered for the efficient amide synthesis. Notably, the catalyst loading is as low as 0.5 mol %. Furthermore, additional experiments were performed to validate the rationale for the superiority of the current catalytic systems over our previous system. It was observed that the ligand structure is one of the reasons for the higher activity. In addition, the higher ratio of the NHC precursor/[Ru] is another important factor for the improvement. Further HR‐MS analysis identified the formation of two mono‐NHC‐Ru species as major species and two Ru species bearing multiple NHC ligands as minor species. Hopefully, the efficient and readily‐accessible catalytic systems reported herein could demonstrate great potential for further practical applications.
Stable Organic Radicals Derived from N‐Heterocyclic Carbenes
Authors: Kim Youngsuk , Lee Eunsung 
Published: July 2018

AbstractOver the past decade, numerous stable organic and main‐group radicals have been synthesized from N‐heterocyclic carbenes (NHCs). The structure of NHCs, in particular, offers electronic stabilization that helps to delocalize the unpaired electron over the molecule. In addition, the sterically bulky substituents of NHCs protect the radical center to prevent detrimental reactions such as dimerization. These advantages enable the straightforward synthesis and characterization of various interesting organic radicals starting from NHCs, which are, these days, widely available. NHCs have enabled the structural characterization of various organic radicals over the past decade, including α‐carbonyl, propargyl, oxyallyl, and triazenyl radicals as notable examples. This minireview summarizes the advances in this field, mainly focusing on the preparation and stability as well as the properties and applications of NHC‐derived organic radicals.
Is ventricular sensing always right, when it is left?
Authors: Biffi Mauro , de Zan Giulia , Massaro Giulia , Angeletti Andrea , Martignani Cristian , Boriani Giuseppe , Diemberger Igor , Ziacchi Matteo 
Published: July 2018

BackgroundVentricular sensing in transvenous cardiac implantable electronic devices (CIEDs) occurs conventionally from the right ventricular (RV) channel, though it evolved from epicardial sensing both in pacemakers and implantable cardioverter‐defibrillators (ICDs).HypothesisThe objective of this study was to observe the reliability of left ventricular (LV) sensing by transvenous leads placed in coronary veins.MethodsLV leads were used for sensing and arrhythmia detection in clinical situations where placement of an RV lead across the tricuspid valve was either not preferred or not feasible, or RV signal was unsuitable for arrhythmia detection, or in the event of sensing failure of an RV lead under advisory in cardiac resynchronization therapy defibrillator (CRTD) recipients.ResultsThirty‐seven patients had an IS‐1 LV lead connected to the RV port of CIEDs (17 pacemakers, 5 cardiac resynchronization therapy pacemaker [CRTP], 2 ICDs, and 13 CRTDs). Along a median 41 (25‐67) months follow‐up, lead performance remained stable; there were neither undersensing nor oversensing of non‐cardiac signals. VT/VF were correctly detected and terminated by ATP and shocks (one and three patients, respectively); no inappropriate arrhythmia detection. Device reprogramming occurred in four CRTD recipients because of transient counting the QRS (short intervals) when paced in LV‐only, and in two with T‐wave oversensing.ConclusionsVentricular sensing by an LV lead is feasible in transvenous devices. Sensing programmability is an unmet need: to fix RV lead sensing issues in cardiac resynchronization therapy (CRT) recipients at no risk of infection (no pocket opening); to avoid interaction with the tricuspid valve; to avoid lead redundancy in the vasculature. Moreover, it will be mandatory owing to the loss of lead interchangeability due to the adoption of DF‐4 and quadripolar leads.
Molecular Photoswitching Aided by Excited‐State Aromaticity
Authors: Durbeej Bo , Wang Jun , Oruganti Baswanth 
Published: July 2018

AbstractCentral to the development of optoelectronic devices is the availability of efficient synthetic molecular photoswitches, the design of which is an arena where the evolving concept of excited‐state aromaticity (ESA) is yet to make a big impact. The aim of this minireview is to illustrate the potential of this concept to become a key tool for the future design of photoswitches. The paper starts with a discussion of challenges facing the use of photoswitches for applications and continues with an account of how the ESA concept has progressed since its inception. Then, following some brief remarks on computational modeling of photoswitches and ESA, the paper describes two different approaches to improve the quantum yields and response times of switches driven by E/Z photoisomerization or photoinduced H‐atom/proton transfer reactions through simple ESA considerations. It is our hope that these approaches, verified by quantum chemical calculations and molecular dynamics simulations, will help stimulate the application of the ESA concept as a general tool for designing more efficient photoswitches and other functional molecules used in optoelectronic devices.