bluuebunny/crossref_metadata_2025 huggingface dataset:
Interferon‐regulated suprabasin is essential for stress‐induced stem‐like cell conversion and therapy resistance of human malignancies
Authors: Hubackova Sona , Pribyl Miroslav , Kyjacova Lenka , Moudra Alena , Dzijak Rastislav , Salovska Barbora , Strnad Hynek , Tambor Vojtech , Imrichova Terezie , Svec Jiri , Vodicka Pavel , Vaclavikova Radka , Rob Lukas , Bartek Jiri , Hodny Zdenek
Published: March 2019

Radiation and chemotherapy represent standard‐of‐care cancer treatments. However, most patients eventually experience tumour recurrence, treatment failure and metastatic dissemination with fatal consequences. To elucidate the molecular mechanisms of resistance to radio‐ and chemotherapy, we exposed human cancer cell lines (HeLa, MCF‐7 and DU145) to clinically relevant doses of 5‐azacytidine or ionizing radiation and compared the transcript profiles of all surviving cell subpopulations, including low‐adherent stem‐like cells. Stress‐mobilized low‐adherent cell fractions differed from other survivors in terms of deregulation of hundreds of genes, including those involved in interferon response. Exposure of cancer cells to interferon‐gamma but not interferon‐beta resulted in the development of a heterogeneous, low‐adherent fraction comprising not only apoptotic/necrotic cells but also live cells exhibiting active Notch signalling and expressing stem‐cell markers. Chemical inhibition of mitogen‐activated protein kinase/ERK kinase (MEK) or siRNA‐mediated knockdown of extracellular signal‐regulated kinase 1/2 (Erk1/2) and interferon responsible factor 1 (IRF1) prevented mobilization of the surviving low‐adherent population, indicating that interferon‐gamma‐mediated loss of adhesion and anoikis resistance required an active Erk pathway interlinked with interferon signalling by transcription factor IRF1. Notably, a skin‐specific protein suprabasin (SBSN), a recently identified oncoprotein, was among the top scoring genes upregulated in surviving low‐adherent cancer cells induced by 5‐azacytidine or irradiation. SBSN expression required the activity of the MEK/Erk pathway, and siRNA‐mediated knockdown of SBSN suppressed the low‐adherent fraction in irradiated, interferon‐gamma‐ and 5‐azacytidine‐treated cells, respectively, implicating SBSN in genotoxic stress‐induced phenotypic plasticity and stress resistance. Importantly, SBSN expression was observed in human clinical specimens of colon and ovarian carcinomas, as well as in circulating tumour cells and metastases of the 4T1 mouse model. The association of SBSN expression with progressive stages of cancer development indicates its role in cancer evolution and therapy resistance.
Shaking table tests on spherical sliding bearings taking eccentricity and uplift into account
Authors: Takeuchi Toru , Nakamura Hideji , Uchida Masakaze , Yoshida Michiyasu , Matsui Ryota
Published: March 2019

Although rubber bearings are popular in Japan as seismic isolation bearings, spherical sliding bearings (SSBs) or friction pendulum bearings are widely used in many countries, including the U.S. In this study, shake table tests on a braced frame supported by SSBs are carried out, and their dependence on pressure and velocity is investigated. Tests under eccentric dead loads and uplift conditions are also conducted to capture their performance. Analytical models that consider pressure and velocity dependence are proposed, and their validity against the experimental results is discussed.
Political Geography
Authors: Agnew John
Published: March 2019

Political geography is that part of human geography most directly involved with studying politics. It is a field of inquiry concerned with the geographical organization of governance, the ways in which geographical imaginations figure in world politics, and the spatial basis to political identities and associated political movements. The geopolitical context of the time has been crucial to the making of academic political geography over the past 100 years. The field has not evolved simply as the result of an internal intellectual dynamic, as one “paradigm” has simply replaced another because of intellectual fashion or academic competition. At the same time, the empirical scope of the field has widened from the original focus on the spatial attributes of statehood and global geopolitics to consider questions, for example about the origins and spread of political movements, the links between places and identities, and geographies of nationalism and ethnic conflict.
Sea Ice, Ice Drift, and Oceanic Circulation
Authors: Thomas David N. , Cottier Finlo R. , Brandon Mark A.
Published: March 2019

The episodic freezing over of the surface waters is arguably the most striking feature of the Southern and Arctic Oceans as well as some subarctic oceans such as the Baltic and Okhotsk Seas. Millions of square kilometers of ocean are covered by ephemeral layers of ice that are on average less than 1 m thick. This pack ice is highly dynamic, drifting on the underlying ocean currents, and its distribution is greatly influenced by prevailing winds. The ice is not simply an impervious layer of frozen water, but does in fact provide a variety of habitats to create a productive biome which is pertinent in the biogeochemical processes in the surface waters and at the air–ocean interface.
Finance and Development
Authors: Dixon Adam D.
Published: March 2019

Finance and the financial system are key components in the workings of a capitalist market economy and of capitalist firms. The absence of finance, or an inefficient financial system, may be detrimental to economic growth and development, which is often the case for poor and developing regions. This entry reviews in the first instance debates over the direction of causality of finance in driving economic growth and development. It then considers global financial integration, including special topics such as Islamic finance and the rise of sovereign wealth funds. The entry concludes with a discussion of financial exclusion and microfinance.
Freshwater Resources: Past, Present, Future
Authors: Petersen Lene , Heynen Martin , Pellicciotti Francesca
Published: March 2019

Fresh water is a crucial resource for human life and natural systems. It is defined as water containing less than 500 ppm of dissolved salts and constitutes only 2.5% of the total water on Earth. Most is stored in ice caps, soil moisture, and groundwater reservoirs, and only a small percentage is accessible for sustainable uses (in lakes, rivers, shallow reservoirs). Freshwater availability changed during human history as a result of increasing drainage and diversions for agriculture as well as impounds and other constructions for hydropower use and flood control. Despite its apparent scarcity, it is of fundamental importance for every form of life and its availability is threatened by climate change and other human pressures. It is now recognized that measures to globally protect freshwater ecosystems and the services they provide are needed. The ongoing debate over competition between human and environmental needs can only be overcome if freshwater ecosystems are valued in a comprehensive way and if their variety of benefits beyond irrigation and energy production are well understood and considered for any type of decision.
Rent Gap
Authors: Addie Jean‐Paul D.
Published: March 2019

The rent gap refers to the difference between the capitalized rent realized from a plot of land and the potential rent possible if it were developed to its “highest and best” use. Introduced by Neil Smith in 1979, the rent gap provides a systematic production‐side theory of urban rent and inner‐city transformation. The concept has been critiqued for dismissing the role of individual agents and consumption preferences in explanatory accounts of gentrification.
Migration: International
Authors: Preston Valerie , Ray Brian
Published: March 2019

International migration, movements of people who leave one country to settle in another, has stimulated a voluminous and growing geographical literature that examines the volume and diversity of migration flows, their meanings for migrants and the societies where they settle, and representations of migration. Contemporary international migration is characterized by increasing spatial variegation and complexity that extend its historical foundations in colonization and imperialism. Globalization, in particular, has encouraged the growth of temporary migration, the feminization of migration, the rise of environmental migrants, and the challenges of increasing ethnoracial diversity. Geographical analysis has been particularly significant in explaining international migration flows and how state representations of migrants are linked to recent efforts to secure national borders.
Development and long‐term stability of a comprehensive daily QA program for a modern pencil beam scanning (PBS) proton therapy delivery system
Authors: Rana Suresh , Bennouna Jaafar , Samuel E. James Jebaseelan , Gutierrez Alonso N.
Published: March 2019

Purpose

The main purpose of this study is to demonstrate the clinical implementation of a comprehensive pencil beam scanning (PBS) daily quality assurance (QA) program involving a number of novel QA devices including the Sphinx/Lynx/parallel‐plate (PPC05) ion chamber and HexaCheck/multiple imaging modality isocentricity (MIMI) imaging phantoms. Additionally, the study highlights the importance of testing the connectivity among oncology information system (OIS), beam delivery/imaging systems, and patient position system at a proton center with multi‐vendor equipment and software.

Methods

For dosimetry, a daily QA plan with spot map of four different energies (106, 145, 172, and 221 MeV) is delivered on the delivery system through the OIS. The delivery assesses the dose output, field homogeneity, beam coincidence, beam energy, width, distal‐fall‐off (DFO), and spot characteristics — for example, position, size, and skewness. As a part of mechanical and imaging QA, a treatment plan with the MIMI phantom serving as the patient is transferred from OIS to imaging system. The HexaCheck/MIMI phantoms are used to assess daily laser accuracy, imaging isocenter accuracy, image registration accuracy, and six‐dimensional (6D) positional correction accuracy for the kV imaging system and robotic couch.

Results

The daily QA results presented herein are based on 202 daily sets of measurements over a period of 10 months. Total time to perform daily QA tasks at our center is under 30 min. The relative difference (Δrel) of daily measurements with respect to baseline was within ± 1% for field homogeneity, ±0.5 mm for range, width and DFO, ±1 mm for spots positions, ±10% for in‐air spot sigma, ±0.5 spot skewness, and ±1 mm for beam coincidence (except 1 case: Δrel = 1.3 mm). The average Δrel in dose output was −0.2% (range: −1.1% to 1.5%). For 6D IGRT QA, the average absolute difference (Δabs) was ≤0.6 ± 0.4 mm for translational and ≤0.5° for rotational shifts.

Conclusion

The use of novel QA devices such as the Sphinx in conjunction with the Lynx, PPC05 ion chamber, HexaCheck/MIMI phantoms, and myQA software was shown to provide a comprehensive and efficient method for performing daily QA of a number of system parameters for a modern proton PBS‐dedicated treatment delivery unit.
The roles of meaningfulness and prior knowledge in younger and older adults' memory performance
Authors: Skinner Donald J. , Price Jodi
Published: March 2019

Meaningfulness and prior knowledge can have differing effects on both metamemory and memory performance. Personally relevant information may be deemed more meaningful, which often can serve as a mediating factor in memory performance. Additionally, information that is congruent with prior knowledge has been shown to be judged as easier to remember and often is better remembered. Both of these effects are most pronounced in older adults. The current study aimed to examine the impact of meaningfulness and prior knowledge on age‐related differences in metamemory (i.e., judgments of learning) and memory performance (i.e., recall and recognition) by manipulating subjective a priori familiarity and personal relevance using age‐relevant study materials (i.e., a student loan application and a Medicare application). Recall metamemory and recall performance results indicate that older adults, but not younger adults, were able to utilize meaningfulness and prior knowledge to boost memory performance.
In‐Air Bubble Phobicity and Bubble Philicity Depending on the Interfacial Air Cushion: Toward Bubbles Manipulation Using Superhydrophilic Substrates
Authors: Xu Bojie , Wang Qianbin , Meng Qing'an , He Meijin , Guo Cheng , Jiang Lei , Liu Huan
Published: March 2019

Bubbles, a typical air‐in‐liquid system including both underwater and in‐air bubbles, are important phenomena involved in our daily life and engineering fields. So far, the fundamental and dynamics for in‐air bubbles largely remain unclear. Here, two typical in‐air wetting states of the bubble are revealed: the bubble‐phobic state in which a bubble with a perfect spherical shape stays on the liquid surface but without coalescence with the liquid; and the bubble‐philic state in which a bubble on the liquid substrate gives a quasi‐hemispherical shape. It is proposed that the bubble phobicity is a typical high‐energy state where the air cushion at the bubble/liquid interface plays a crucial role in preventing their coalescence by generating an energy barrier. By applying an external force to overcome the energy barrier, the bubble will distort and finally be stabilized in a bubble‐philic state. It is demonstrated that superhydrophilic substrates enable manipulating bubbles in air: a superhydrophilic surface with microscale hairy textures shows robust in‐air repellence to the bubbles, while a hemispherical bubble is capable of transport directionally in air on a superhydrophilic conical fiber. Here, the concept of superwetting into air‐in‐air system (liquid films) is promoted, which may open a new perspective in surface and interface chemistry.
Rotibot: Use of Rotifers as Self‐Propelling Biohybrid Microcleaners
Authors: Soto Fernando , Lopez‐Ramirez Miguel Angel , Jeerapan Itthipon , Esteban‐Fernandez de Avila Berta , Mishra Rupesh Kumar , Lu Xiaolong , Chai Ingrid , Chen Chuanrui , Kupor Daniel , Nourhani Amir , Wang Joseph
Published: March 2019

Self‐propelled biohybrid microrobots, employing marine rotifers as their engine, named “rotibot,” are presented and their practical utility and advantages for environmental remediation are demonstrated. Functionalized microbeads are attached electrostatically within the rotifer mouth and aggregated inside their inner lip. The high fluid flow toward the mouth, generated by the strokes of rotifer cilia bands, forces an extremely efficient transport of the contaminated sample over the active surfaces of the functionalized microbeads. The reactive particles confined around the rotifer's lip are thus exposed to a high flow rate of the pollutant solution, resulting in dramatically accelerated decontamination processes, without external mixing or harmful fuels. Theoretical simulations, modeling the greatly enhanced fluid dynamic associated with such built‐in mixing effect, correlate well with the experimental observations. The rotibot thus proves to be an effective, versatile, and robust dynamic microcleaning platform for removing diverse environmental pollutants. Microbeads functionalized with lysozyme and organophosphorus hydrolase enzymes are shown to be extremely useful for enzymatic biodegradation of Escherichia coli and the nerve agent methyl paraoxon, respectively, while ligand (meso‐2,3‐dimercaptosuccinic acid) modified beads are used for removing heavy metal contaminants. Rotifer‐based biohybrid microrobots hold considerable promise as self‐propelling dynamic pumps for diverse large‐scale environmental remediation applications.
Targeted Magnetic Resonance Imaging and Modulation of Hypoxia with Multifunctional Hyaluronic Acid‐MnO2 Nanoparticles in Glioma
Authors: Fu Chaoping , Duan Xiaohui , Cao Minghui , Jiang Shuqi , Ban Xiaohua , Guo Na , Zhang Fang , Mao Jiaji , Huyan Ting , Shen Jun , Zhang Li Ming
Published: March 2019

Manganese dioxide (MnO2)‐based nanoparticles are a promising tumor microenvironment‐responsive nanotheranostic carrier for targeted magnetic resonance imaging (MRI) and for alleviating tumor hypoxia. However, the complexity and potential toxicity of the present common synthesis methods limit their clinical application. Herein, multifunctional hyaluronic acid‐MnO2 nanoparticles (HA‐MnO2 NPs) are synthesized in a simple way by directly mixing sodium permanganate with HA aqueous solutions, which serve as both a reducing agent and a surface‐coating material. The obtained HA‐MnO2 NPs show an improved water‐dispersibility, fine colloidal stability, low toxicity, and responsiveness to the tumor microenvironment (high H2O2 and high glutathione, low pH). After intravenous injection, HA‐MnO2 NPs exhibit a high imaging sensitivity for detecting rat intracranial glioma with MRI for a prolonged period of up to 3 d. These nanoparticles also effectively alleviate the tumor hypoxia in a rat model of intracranial glioma. The downregulation of VEGF and HIF‐1α expression in intracranial glioma validates the sustained attenuation effect of HA‐MnO2 NPs on tumor hypoxia. These results show that HA‐MnO2 NPs can be used for sensitive, targeted MRI detection of gliomas and simultaneous attenuation of tumor hypoxia.
High Operation Stability of Ultraflexible Organic Solar Cells with Ultraviolet‐Filtering Substrates
Authors: Kimura Hiroki , Fukuda Kenjiro , Jinno Hiroaki , Park Sungjun , Saito Masahiko , Osaka Itaru , Takimiya Kazuo , Umezu Shinjiro , Someya Takao
Published: March 2019

Ultralightweight and flexible power sources are essential for driving textile or wearable electronic devices and soft robots because they do not induce discomfort or limit movement when they are attached to human skin, textiles, or soft actuators. Organic solar cells (OSCs) are good candidates for developing such power sources because they have the advantages of being lightweight and flexible. However, achieving operational stability and ultrathin shape simultaneously remains difficult because the ultrathin substrate cannot prevent the penetration of ultraviolet (UV) light, which is major a cause for the degradation of OSCs. Here, ultrathin OSCs that show great operational stability and high performance are reported. The 1.3 µm thick transparent polyimide utilized as a substrate can block light of 350 nm wavelength in the UV range by 90%. The ultrathin OSCs with the transparent polyimide substrate produce a power conversion efficiency (PCE) of 9.0% and realize both photostability and operational stability. The PCE was maintained at 90% after 3 h in a maximum power point tracking test, indicating much better operational stability than the reference rigid OSCs.
Electrolytes and Electrolyte/Electrode Interfaces in Sodium‐Ion Batteries: From Scientific Research to Practical Application
Authors: Huang Yongxin , Zhao Luzi , Li Li , Xie Man , Wu Feng , Chen Renjie
Published: March 2019

Sodium‐ion batteries (SIBs) have drawn considerable interest as power‐storage devices owing to the wide abundance of their constituents and low cost. To realize a high performance–price ratio, the cathode and anode materials must be optimized. As essential components of SIBs, electrolytes should have wide electrochemical windows, high thermal stability, and exceptional ionic conductivity. Therefore, improved electrolytes, based on various materials and compositions, are developed to meet the practical demands of SIBs, including organic electrolytes, ionic liquids, aqueous, solid electrolytes, and hybrid electrolytes. Although mature organic electrolytes are currently used in production, aqueous and solid electrolytes show advantages for future applications, as discussed here in detail. Current efforts in modifying electrolytes to optimize their interfacial compatibility with electrodes, leading to longer battery lifetimes and greater safety, are described. The advanced characterization techniques used to investigate the properties of electrolytes and interfaces are introduced, and the reaction processes and degradation mechanisms of SIBs are revealed. Furthermore, the practical prospects of SIBs promoted by high‐quality electrolytes appropriately matched with electrodes are predicted and directions for developing next‐generation SIBs are suggested.
Wet/Sono‐Chemical Synthesis of Enzymatic Two‐Dimensional MnO2 Nanosheets for Synergistic Catalysis‐Enhanced Phototheranostics
Authors: Tang Wei , Fan Wenpei , Zhang Weizhong , Yang Zhen , Li Ling , Wang Zhantong , Chiang Ya‐Ling , Liu Yijing , Deng Liming , He Liangcan , Shen Zheyu , Jacobson Orit , Aronova Maria A. , Jin Albert , Xie Jin , Chen Xiaoyuan
Published: March 2019

2D nanomaterials have attracted broad interest in the field of biomedicine owing to their large surface area, high drug‐loading capacity, and excellent photothermal conversion. However, few studies report their “enzyme‐like” catalytic performance because it is difficult to prepare enzymatic nanosheets with small size and ultrathin thickness by current synthetic protocols. Herein, a novel one‐step wet‐chemical method is first proposed for protein‐directed synthesis of 2D MnO2 nanosheets (M‐NSs), in which the size and thickness can be easily adjusted by the protein dosage. Then, a unique sono‐chemical approach is introduced for surface functionalization of the M‐NSs with high dispersity/stability as well as metal‐cation‐chelating capacity, which can not only chelate 64Cu radionuclides for positron emission tomography (PET) imaging, but also capture the potentially released Mn2+ for enhanced biosafety. Interestingly, the resulting M‐NS exhibits excellent enzyme‐like activity to catalyze the oxidation of glucose, which represents an alternative paradigm of acute glucose oxidase for starving cancer cells and sensitizing them to thermal ablation. Featured with outstanding phototheranostic performance, the well‐designed M‐NS can achieve effective photoacoustic‐imaging‐guided synergistic starvation‐enhanced photothermal therapy. This study is expected to establish a new enzymatic phototheranostic paradigm based on small‐sized and ultrathin M‐NSs, which will broaden the application of 2D nanomaterials.
High Phase Purity of Large‐Sized 1T′‐MoS2 Monolayers with 2D Superconductivity
Authors: Peng Jing , Liu Yuhua , Luo Xiao , Wu Jiajing , Lin Yue , Guo Yuqiao , Zhao Jiyin , Wu Xiaojun , Wu Changzheng , Xie Yi
Published: March 2019

The development of transition metal dichalcogenides has greatly accelerated research in the 2D realm, especially for layered MoS2. Crucially, the metallic MoS2 monolayer is an ideal platform in which novel topological electronic states can emerge and also exhibits excellent energy conversion and storage properties. However, as its intrinsic metallic phase, little is known about the nature of 2D 1T′‐MoS2, probably because of limited phase uniformity (<80%) and lateral size (usually <1 µm) in produced materials. Herein, solution processing to realize high phase‐purity 1T′‐MoS2 monolayers with large lateral size is demonstrated. Direct chemical exfoliation of millimeter‐sized 1T′ crystal is introduced to successfully produce a high‐yield of 1T′‐MoS2 monolayers with over 97% phase purity and unprecedentedly large size up to tens of micrometers. Furthermore, the large‐sized and high‐quality 1T′‐MoS2 nanosheets exhibit clear intrinsic superconductivity among all thicknesses down to monolayer, accompanied by a slow drop of transition temperature from 6.1 to 3.0 K. Prominently, unconventional superconducting behavior with upper critical field far beyond the Pauli limit is observed in the centrosymmetric 1T′‐MoS2 structure. The results open up an ideal approach to explore the properties of 2D metastable polymorphic materials.
Three‐Component [2+2+1] Gold(I)‐Catalyzed Oxidative Generation of Fully Substituted 1,3‐Oxazoles Involving Internal Alkynes
Authors: Dubovtsev Alexey Yu. , Dar'in Dmitry V. , Kukushkin Vadim Yu.
Published: March 2019

Three‐component [2+2+1] gold(I)‐catalyzed reaction of internal alkynes (alkynyl esters or ‐ketones), nitriles, and 2‐chloropyridine N‐oxide led to a wide range of fully substituted 1,3‐oxazoles (32 examples; up to 92% isolated yields). Nitrile R3CN species, employed in the reaction as both reactants and solvents, comprise conventional nitriles (R3=Alk, Ar) and also push‐pull systems such as cyanamides (R3=NH2 and NAlk2) and the thiocyanate (R3=SPr). The advantages of the developed method include mild reaction conditions, high functional‐group tolerance, broad range of substituents R1/R3 along with a possibility of easy modification of COR2 or the amino group when R1=NH2.

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Metal‐Free Promoted CF2/CF3‐Difunctionalization of Unactivated Alkenes
Authors: Li Ming , Zhu Xin‐Yu , Qiu Yi‐Feng , Han Ya‐Ping , Xia Yu , Wang Cui‐Tian , Li Xue‐Song , Wei Wan‐Xu , Liang Yong‐Min
Published: March 2019

An operationally simple radical difluoroalkylation/trifluoromethylation and alkynylation of unactivated alkenes under mild conditions has been developed. Through this protocol, a series of CF2/CF3‐ substituted linear alkynyl ketones were synthesized via a unique 1,2‐alkynyl radical migration. Notably, no transition‐ metal catalyst is needed in the developed reaction system, and excellent functional group compatibility was observed.

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Artificial Red Blood Cells Constructed by Replacing Heme with Perfluorodecalin for Hypoxia‐Induced Radioresistance
Authors: Yu Peng , Han Xiaoxue , Yin Lining , Hui Kangyu , Guo Yunfei , Yuan Ahu , Hu Yiqiao , Wu Jinhui
Published: March 2019

Radioresistance, a serious problem during radiotherapy (RT) caused by hypoxia, results in tumor relapse. Hemoglobin‐based oxygen carriers (HBOCs) which can deliver oxygen, offer a promising option to cancer patients with radioresistance. However, the potential autoxidative cytotoxicity and renal toxicity of heme in hemoglobin (Hb) hamper their clinical application. Thus, here, a nano red blood cell (nnRBC) is fabricated that replaces heme with perfluorodecalin (FDC), a hydrophobic, high oxygen carrying fluorocarbon, and coated with membranes of RBCs. For the first time, nnRBCs provide a new method for the delivery of FDC since it cannot be emulsified by any FDA approved emulsifiers. nnRBCs encapsulate FDC with 8000% (w/w) drug loading efficiency and show superior storage stability within seven days. After intravenous delivery, nnRBCs reverse tumor hypoxia effectively compared with RT treatment alone. Of note, the components of nnRBCs are all from organisms or safe substances that have been verified by human testing, which gives nnRBCs great potential to rapidly enter into clinical trials.
Insights of Pressure‐induced Unfolding of β‐Lactoglobulin as Revealed by Steered Molecular Dynamics
Authors: Zhang Zhuo , Hu Hao , Xu Xiaoyun , Pan Siyi , Peng Bangzhu
Published: March 2019

High hydrostatic pressure (HHP) has been widely used in various industries, and the protein as one of the most noticeable bio‐macromolecules has exhibited distinct structural and functional characteristics under HHP conditions. In this work, steered molecular dynamics (SMD) simulations of β‐lactoglobulin (βlg) are exploited to investigate the flexibility of the individual secondary structural element of the polypeptide. The two loops and the two helices on the two sides of the molecular β‐barrel are found to be highly flexible and migrate toward the hydrophobic interior of the protein at relatively low pressures. Interestingly, there is evidence illustrating that water penetrations only occur from the loop‐side of the barrel under pressurizations, which is favored by the enlarged β‐barrel induced through the loop compression. Moreover, increased stability of βlg is attributed to the rigid regions of the protein molecule. N‐ and C‐termini of the polypeptide chain are also found to be of great importance to pressure‐induced unfolding of βlg. It is found the modeling results agree with previous experimental observations, demonstrating the validity of the applications of SMD for studies on pressure‐induced protein unfolding. Such methodology will provide new insight into HHP and be generalized for more complicated systems such as enzymes.
Metallic Nanoparticle Inks for 3D Printing of Electronics
Authors: Tan Hong Wei , An Jia , Chua Chee Kai , Tran Tuan
Published: March 2019

The three‐dimensional (3D) printed electronics additive manufacturing industry sector has grown substantially in the past few years, and there is increasing demand for different types of metallic nanoparticle inks in electronics printing for various applications. Metallic nanoparticle inks are commonly used for fabricating conductive tracks and patterns due to their relatively high electrical conductivity as compared to other types of inks, and they can be further categorized into single‐element metallic nanoparticle inks, alloy metallic nanoparticle inks, metallic oxide nanoparticle inks, and core–shell bimetallic nanoparticle (BNP) inks. It is critical to gain a deep understanding of the metallic nanoparticle inks used in 3D printed electronics as the material properties of these inks can directly affect the final electrical and mechanical properties of the printed patterns. This review presents an overview of the available metallic nanoparticle inks used for 3D printing of electronics, and critically reviews the strengths and weaknesses of each type of ink. Finally, the challenges of metallic nanoparticle inks in 3D printed electronics are also discussed along with the future outlook for 3D printed electronics.
Energy‐Efficient Metal–Insulator–Metal‐Semiconductor Field‐Effect Transistors Based on 2D Carrier Gases
Authors: Liao Meiyong , Sang Liwen , Shimaoka Takehiro , Imura Masataka , Koizumi Satoshi , Koide Yasuo
Published: March 2019

2D electron and hole gases (2DEG or 2DHG) based on semiconductor surface/interface or 2D materials are promising for next‐generation integrated circuits and high‐frequency and ‐power electronics. To reduce power consumption, normally off operation and low‐switching‐loss metal‐oxide field‐effect transistors (MOSFETs) based on 2DEG or 2DHG are highly in demand. The present methods to achieve normally off MOSFETs have various shortcomings such as reduction in carrier mobility, sacrifice of drain current, high uncertainty in threshold voltage, and poor reliability. Here a universal device concept called a metal–insulator–metal‐semiconductor field‐effect transistor (MIMS‐FET) to achieve normally off operation is shown by combining the advantages of MOSFETs and metal‐semiconductor FETs. High‐performance MIMS‐FETs based on 2DHG of diamond with a low subthreshold swing of ≈76 mV dec−1, on–off current ratio exceeding 109, and high thermal stability up to 623 K are realized. The current work provides a strategy to develop next‐generation energy‐efficient electronic circuits as well as fail‐safety power devices. The proposed concept also adds diversity to the semiconductor devices family.
Dimensionality Dependent Plasticity in Halide Perovskite Artificial Synapses for Neuromorphic Computing
Authors: Kim Sung‐Il , Lee Yeongjun , Park Min‐Ho , Go Gyeong‐Tak , Kim Young‐Hoon , Xu Wentao , Lee Hyeon‐Dong , Kim Hobeom , Seo Dae‐Gyo , Lee Wanhee , Lee Tae‐Woo
Published: March 2019

The hysteretic behavior of organic–inorganic halide perovskites (OHPs) are exploited for application in neuromorphic electronics. Artificial synapses with 2D and quasi‐2D perovskite are demonstrated that have a bulky organic cation (phenethylammonium (PEA)) to form structures of (PEA)2MAn‐1PbnBr3n+1. The OHP films have morphological properties that depend on their structure dimensionality (i.e., n value), and artificial synapses fabricated from them show synaptic responses such as short‐term plasticity, paired‐pulse facilitation, and long‐term plasticity. The operation mechanism of OHP artificial synapses are also analyzed depending on the dimensionality and it is found that quasi‐2D (n = 3–5) OHP artificial synapses show much longer retention than 2D and 3D OHP counterparts. The calculated energy consumption of a 2D OHP artificial synapse (≈0.7 fJ per synaptic event) is comparable to that of biological synapses (1–10 fJ per synaptic event). These OHP artificial synapses may enable development of neuromorphic electronics that use very little energy.
An Electric‐Field‐Controlled High‐Speed Coexisting Multibit Memory and Boolean Logic Operations in Manganite Nanowire via Local Gating
Authors: Shi Qian , Jiang Fengxian , Yu Yang , Lin Hanxuan , Kou Yunfang , Miao Tian , Liu Hao , Yang Wenting , Wang Wenbin , Cai Peng , Xu Xiaohong , Guo Hangwen , Yin Lifeng , Shen Jian
Published: March 2019

In‐memory computing is currently a hot research field and shows potential to overcome the Von Neumann bottleneck in conventional computers. Most proposed designs demand use of electrical current, which will generate substantial heat and power consumption when miniaturized. Here, multibit memory and Boolean logic operation are shown at the same location in a manganite nanowire through electric field exploitation. Local electrical fields are employed to control eight‐level resistive states with high accuracy along with Boolean logic operations. Such architecture only requires current density of 4 × 101 A cm−2 for resistance measurements, which is four orders of magnitude smaller than state‐of‐the‐art designs. In addition, the device shows a resistive switching time within 8 ns, which is suitable for high‐speed electronics technology. This study highlights a route towards in‐memory computing with low heat dissipation and power consumption.
A Stand‐Alone Si‐Based Porous Photoelectrochemical Cell
Authors: Vijselaar Wouter J. C. , Perez‐Rodriguez Paula , Westerik Pieter J. , Tiggelaar Roald M. , Smets Arno H. M. , Gardeniers Han , Huskens Jurriaan
Published: March 2019

Wireless photoelectrochemical (PEC) devices promise easy device fabrication as well as reduced losses. Here, the design and fabrication of a stand‐alone ion exchange material‐embedded, Si membrane‐based, photoelectrochemical cell architecture with micron‐sized pores is shown, to overcome the i) pH gradient formation due to long‐distance ion transport, ii) product crossover, and iii) parasitic light absorption by application of a patterned catalyst. The membrane‐embedded PEC cell with micropores utilizes a triple Si junction cell as the light absorber, and Pt and IrOx as electrocatalysts for the hydrogen evolution reactions and oxygen evolution reactions, respectively. The solar‐to‐hydrogen efficiency of 7% at steady‐state operation, as compared to an unpatterned ηPV of 10.8%, is mainly attributed to absorption losses by the incorporation of the micropores and catalyst microdots. The introduction of the Nafion ion exchange material ensures an intrinsically safe PEC cell, by reducing the total gas crossover to <0.1%, while without a cation exchange membrane, a crossover of >6% is observed. Only in a pure electrolyte of 1 m H2SO4, a pH gradient‐free system is observed thus completely avoiding the build‐up of a counteracting potential.
Structural Engineering of Hierarchical Micro‐nanostructured Ge–C Framework by Controlling the Nucleation for Ultralong‐Life Li Storage
Authors: Zhang Shilin , Zheng Yang , Huang Xuejuan , Hong Jian , Cao Bin , Hao Junnan , Fan Qining , Zhou Tengfei , Guo Zaiping
Published: March 2019

The rational design of a proper electrode structure with high energy and power densities, long cycling lifespan, and low cost still remains a significant challenge for developing advanced energy storage systems. Germanium is a highly promising anode material for high‐performance lithium ion batteries due to its large specific capacity and remarkable rate capability. Nevertheless, poor cycling stability and high price significantly limit its practical application. Herein, a facile and scalable structural engineering strategy is proposed by controlling the nucleation to fabricate a unique hierarchical micro‐nanostructured Ge–C framework, featuring high tap density, reduced Ge content, superb structural stability, and a 3D conductive network. The constructed architecture has demonstrated outstanding reversible capacity of 1541.1 mA h g−1 after 3000 cycles at 1000 mA g−1 (with 99.6% capacity retention), markedly exceeding all the reported Ge–C electrodes regarding long cycling stability. Notably, the assembled full cell exhibits superior performance as well. The work paves the way to constructing novel metal–carbon materials with high performance and low cost for energy‐related applications.
Clinical Improvement Interventions for Residents and Practicing Physicians: A Scoping Review of Coaching and Mentoring for Practice Improvement
Authors: MacKenzie Casey , Chan Teresa M. , Mondoux Shawn
Published: March 2019

Background

Graduate medical education (GME) bodies are beginning to mandate coaching as an integral part of the learning process, in addition to current requirements for mentorship. Once an emergency medicine physician transitions beyond graduate training, there is no requirement and little focus on coaching as a method of improving or maintaining clinical practice. Our objective was to understand and describe the current state of the published literature with regard to the use of coaching and mentorship for both GME and practicing physicians.

Methods

We conducted a structured review of the literature through PubMed and Google Scholar and included all articles applying coaching or mentorship modalities to GME trainees or practicing physicians. A Google Form was used for standardized data abstraction. Data were collected pertaining to the settings of intervention, the nature of the intervention, its effect, and its resource requirements.

Results

A total of 3,546 papers were isolated during the literature review. After exclusion, 186 underwent full‐text review by the authors of which 126 articles were included in the final data analysis. Eighty‐two articles (65%) pertained to mentorship and 14 (11%) to coaching; the remainder of the articles discussed a combination or variation of these two concepts. Fifty‐three (42%) articles were descriptive studies and 35 (28%) were narrative reviews or commentaries. Forty‐seven (37%) articles originated from within surgical specialties and coaching was most commonly applied to procedural or manual skills with 22 (17%) instances among all studies.

Conclusions

Most literature on coaching and mentorship is descriptive or narrative, and few papers are in the specialty of emergency medicine. Most interventions are limited to single instances of coaching or mentorship without longitudinal application of the intervention. There is an important need to study and publish further evidence on coaching interventions.
The biology of frailty in humans and animals: Understanding frailty and promoting translation
Authors: Bisset Elise S. , Howlett Susan E.
Published: March 2019

Frailty is a state of high vulnerability to adverse health outcomes. This concept is used to explain the heterogeneity in rates of aging in people of the same age. Frailty has important clinical implications, because even minor stressors can lead to adverse outcomes, including death, in frail individuals. Although frailty mechanisms are not well understood, advances in our ability to qualify frailty have encouraged efforts in this area. Quantification of frailty with both “frailty phenotype” and “frailty index” approaches has begun to highlight putative frailty mechanisms and new animal models of frailty are inspiring preclinical research. These models either adapt frailty phenotype and frailty index tools for use in animals or they use genetically manipulated mice that mimic conditions seen in frailty (eg, inflammation, sarcopenia, weakness). This review: describes commonly used tools to quantify frailty clinically, discusses potential frailty mechanisms, and describes animal models of frailty. It also highlights how these models have been used to explore frailty mechanisms and potential frailty interventions, including pharmacological treatments, diet, and exercise. These exciting new developments in the field have the potential to facilitate translational research, improve our understanding of mechanisms of frailty, and help develop new interventions to mitigate frailty in our aging population.
A modified mixed‐acid catalytic system for Beckmann rearrangement of cyclohexanone oxime
Authors: Du Chencan , Zhang Jisong , Li Liantang , Wang Kai , Luo Guangsheng
Published: March 2019

ε‐Caprolactam (CPL) is mainly produced through Beckmann rearrangement of cyclohexanone oxime catalyzed by oleum in industry nowadays, which suffers the problems like high viscosity and bad mixing, leading to multiple by‐products. To this end, a modified mixed‐acid catalytic system containing oleum and trifluoroacetic acid (TFA) was proposed to intensify the reaction. The viscosity of the reaction system was studied and the effects of several experimental parameters on the reaction rate and selectivity were also investigated, including oleum/oxime ratio, TFA/oleum ratio, temperature, and SO3 concentration. Extremely high selectivity (>99.6%) was obtained under all conditions, revealing that by‐products in industrial process were mainly formed owing to the insufficient mixing and poor mass and heat transfer rather than experimental parameters. A preliminary mathematical model considering the effect of CPL was developed to predict the reaction rate. These results are helpful to improve the industrial process of CPL production.
Reversal of direct oral anticoagulants: Guidance from the Anticoagulation Forum
Authors: Cuker Adam , Burnett Allison , Triller Darren , Crowther Mark , Ansell Jack , Van Cott Elizabeth M. , Wirth Diane , Kaatz Scott
Published: March 2019

Two specific reversal agents for direct oral anticoagulants (DOACs) have been approved in the United States: idarucizumab for dabigatran reversal and andexanet alfa for apixaban and rivaroxaban reversal. Non‐specific prohemostatic agents such as prothrombin complex concentrate (PCC) and activated PCC have also been used for DOAC reversal. The goal of this document is to provide comprehensive guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of DOAC reversal agents. We discuss indications for reversal, provide guidance on how the individual reversal agents should be administered, and offer suggestions for stewardship at the health system level.
Time matching between grooming partners: Do methodological distinctions between short versus long‐term reciprocation matter?
Authors: Dunayer Erica S. , Tyrrell Maura , Balasubramaniam Krishna N. , Berman Carol M.
Published: March 2019

Primatologists have long focused on grooming exchanges to examine aspects of social relationships, co‐operation, and social cognition. One particular interest is the extent to which reciprocating grooming partners time match, and the time frame over which they do so. Conclusions about time matching vary across species. Generally, researchers focus on the duration of pauses between grooming episodes that involve a switch in partner roles and choose a cut‐off point to distinguish short from longer‐term reciprocation. Problematically, researchers have made inconsistent choices about cut‐offs. Such methodological variations are potentially concerning, as it is unclear whether inconsistent conclusions about short‐term time matching are attributable to species/ecological differences, or are due in part to methodological inconsistency. We ask whether various criteria for separating short versus long‐term reciprocation influence conclusions about short‐term time matching using data from free‐ranging rhesus (
Macaca mulatta) and captive‐crested macaques (
Macaca nigra). We compare several commonly used cut‐offs to ones generated by the currently preferred approach—survival analysis. Crested macaques displayed a mild degree of time matching regardless of the cutoff used. For rhesus macaques, whereas most cut‐offs yielded similar degrees of time matching as the one derived from survival analysis, very short ones significantly underestimated both the degree of time matching and the influence of rank distance on time matching. Although researchers may have some flexibility in their choice of cut‐offs, we suggest that they employ caution by using survival analysis when possible, and when not possible, by avoiding very short time windows.
Echogenic cavum septi pellucidi is associated with mild callosal dysgenesis on postnatal MRI
Authors: Stanislavsky Alexandra , Goergen Stacy
Published: March 2019

We present a previously unreported association between the sonographic finding of an echogenic cavum septi pellucidi (CSP), concurrent hypointense signal within the CSP on fetal MRI and postnatal MR evidence of dysgenesis of the rostrum and genu of the corpus callosum as well as abnormal shortening of the septal leaflets. An echogenic or non‐fluid filled CSP in the fetus at the midtrimester ultrasound is likely to represent a form of mild callosal dysgenesis. Perinatal assessment of vision and endocrine function and clinical follow‐up of neurodevelopment and growth are probably indicated in such cases.
Eine flexible Kupplung von Aldehyden und Alkenen ermöglicht die diastereo‐ und enantioselektive Herstellung von Stereotriaden
Authors: Li Jing , Preinfalk Alexander , Maulide Nuno
Published: March 2019

Eine flexible, redoxneutrale Kupplung von Aldehyden mit Alkenen ermöglicht die direkte Bildung von Stereotriaden mit perfekter Enantio‐ und Diastereoselektivität und unter milden Bedingungen, ausgehend von einem einzelnen chiralen Zentrum. Die vielseitige Anwendbarkeit dieser Methode wird durch die Installation von Heteroatomen in der Kette ermöglicht, wodurch verschiedenste chirale Bausteine hergestellt werden können. Eine formale Synthese von (+)‐Neopeltolid verdeutlicht die breite Anwendbarkeit dieser Methode.
Phenanthroline‐Catalyzed Stereoretentive Glycosylations
Authors: Yu Fei , Li Jiayi , DeMent Paul M. , Tu Yi‐Jung , Schlegel H. Bernhard , Nguyen Hien M.
Published: March 2019

Carbohydrates are essential moieties of many bioactive molecules in nature. However, efforts to elucidate their modes of action are often impeded by limitations in synthetic access to well‐defined oligosaccharides. Most of the current methods rely on the design of specialized coupling partners to control selectivity during the formation of glycosidic bonds. Reported herein is the use of a commercially available phenanthroline to catalyze stereoretentive glycosylation with glycosyl bromides. The method provides efficient access to α‐1,2‐cis glycosides. This protocol has been performed for the large‐scale synthesis of an octasaccharide adjuvant. Density‐functional theory calculations, together with kinetic studies, suggest that the reaction proceeds by a double SN2 mechanism.
Anchor Residues Guide Form and Function in Grafted Peptides
Authors: Yin Huawu , Craik David J. , Wang Conan K.
Published: March 2019

Loops at protein–protein interfaces are a rich source of peptide leads that have high specificity and low toxicity. Although such peptides typically need to be constrained to overcome thermodynamic and metabolic limitations, design guidelines to obtain a successfully constrained peptides, and thus facilitate the transition from loop to drug, are relatively poorly formulated. In this work, we surveyed the structures of interface loops and found the position of the terminal residues to be a key determinant of conformation. We used this knowledge to improve the process of molecular grafting, a valuable approach for constraining and stabilising peptides by fusing them to a suitable scaffold. We show that an informed choice of where a loop is “anchored” to a scaffold improves its form and function. This knowledge can help guide the choice of loop and its matching scaffold, and thus increase the success rate for designing stable and potent peptide drug leads.