bluuebunny/crossref_metadata_2025 huggingface dataset:
Three-dimensional growth of breast cancer cells potentiates the anti-tumor effects of unacylated ghrelin and AZP-531
Authors: Au CheukMan C , Furness John B , Britt Kara , Oshchepkova Sofya , Ladumor Heta , Soo Kai Ying , Callaghan Brid , Gerard Celine , Inghirami Giorgio , Mittal Vivek , Wang Yufeng , Huang Xin Yun , Spector Jason A , Andreopoulou Eleni , Zumbo Paul , Betel Doron , Dow Lukas , Brown Kristy A
Published: July 2020

Breast cancer is the most common type of cancer in women and notwithstanding important therapeutic advances, remains the second leading cause of cancer-related death. Despite extensive research relating to the hormone ghrelin, responsible for the stimulation of growth hormone release and appetite, little is known of the effects of its unacylated form, especially in cancer. The present study aimed to characterize effects of unacylated ghrelin on breast cancer cells, define its mechanism of action, and explore the therapeutic potential of unacylated ghrelin or analog AZP-531. We report potent anti-tumor effects of unacylated ghrelin, dependent on cells being cultured in 3D in a biologically-relevant extracellular matrix. The mechanism of unacylated ghrelin-mediated growth inhibition involves activation of Gαi and suppression of MAPK signaling. AZP-531 also suppresses the growth of breast cancer cells in vitro and in xenografts, and may be a novel approach for the safe and effective treatment of breast cancer.
Analysis of the Educational Impact of M-Learning and Related Scientific Research
Authors: Fombona Javier , Pascual María Angeles , Pérez Ferra Miguel
Published: July 2020

The deep penetration and global impact of mobile devices has led the scientific community to undertake a thorough analysis of the implications of this phenomenon. Researchers need to determine their true real effect and how they can best be used to manage information and build knowledge. This study has examined recent investigations on the subject of mobile learning and carried out a descriptive analysis of a sample of registers indexed on the Web of Science research platform in 2015–16. An exhaustive content analysis has revealed new areas where M-Learning is being implemented, especially in the teaching of foreign languages, the emergence of social interaction methodologies in Secondary Education, evolving forms of collaborative relationships, work with clearly defined student profiles and the use of virtual immersive and innovative spaces in Higher Education. This paper also emphasizes the presence of previously unknown, transcendent problems associated with M-learning, such as the collateral addiction effect, and its interference in the classroom. Finally, our study suggests that teachers could embrace these technological proposals and include them in their strategies. Indeed, it might be necessary to flip the process, so this research could be the start of the generation and design of innovative guidelines to manage these forms and content.
How the Education Community Perceives Cyberbullying: a Comparison of Students, Teachers and Families
Authors: Bautista Alcaine Pablo , Sánchez Eva Vicente
Published: July 2020

This study aims to find out how the groups that form the education community (students, teachers, families) differ in terms of the various characteristics surrounding the cyberbullying phenomenon. To do this, we conducted research using a selective correlational and cross-sectional design to analyze relationships and differences among variables: defining cyberbullying, typology, involved roles, possible causes and coping strategies in the different groups. The study recruited 116 participants as follows: 51% were year-6 Primary Education students; 29% were students’ family members; 20% were school teachers. We collected data through an ad hoc questionnaire that a group of experts had previously validated. The results of the data analysis showed that significant differences appeared in terms of: how typologies were perceived; the importance of roles; coping strategies for cyberbullying.
Using learning analytics to engage students: Improving teaching practices through informed interactions
Authors: Naujokaitienė Justina , Tamoliūnė Giedrė , Volungevičienė Airina , Duart Josep M.
Published: July 2020

Student engagement is one of the most relevant topics within the academic and research community nowadays. Higher education curriculum, teaching and learning integrate new technology- supported learning solutions. New methods and tools enhance teacher and learner interactions and influence learner engagement positively. This research addresses the need to explore new ways of improving teaching practices to better engage students with the help of learning analytics. The paper investigates how university teachers use the data from learning analytics to observe learners and to engage them in online learning. Qualitative inquiry was chosen to approach the research problem, and semi-structured interviews with the teachers using (blended) online learning were conveyed to explore teacher practices in students’ behaviour and engagement observations online, disclosing teachers’ abilities to understand the challenging learner engagement process based on the data from learning analytics. The new evidence provided by this research highlights the successful practices in the use of learning analytics data to observe students’ behaviour and engagement and to inform teachers on the presence needed in order to develop learner–centred activities and to make curriculum changes. The limitation of this study lies in the fact that the different online teaching experiences that research participants had might have restricted their understanding of the use of LA data for curriculum development and learners’ engagement.
Smart Learning Environments and Ergonomics: An Approach to the State of the Question
Authors: García-Tudela Pedro Antonio , Prendes-Espinosa María Paz , Solano-Fernández Isabel María
Published: July 2020

Educational technology evolves constantly, in line with the innovative technologies we implement, but always catering for the improvement of teaching and learning. For this, Smart Learning Environments (SLE) emerge as an optimal alternative to traditional teaching as, through ergonomics, an inclusive outlook which is bound to enhance the educational experience of every student is provided. The method utilized is based on a systematic review of the existing literature which has allowed us to analyze in depth a final sample of 19 documents after an initial review of 633, being these all the works published between 2013 and 2019.Therefore, the principal objective of the present work is carrying out an analysis of the state of the art in relation to ergonomics, inclusiveness and the SLE. The analysis of results is performed utilizing a semantic network, generated through atlas.ti. v.8, by means of which 3 categories, 10 codes and 33 quotes are extracted. Namely, the results reveal the emerging nature of the thematic line researched and how ergonomics is linked to inclusiveness and stands out as one of the most defining components when designing an educational proposal based on SLE.
Assessment of Temperature Variability Effect on Rice Production in Nasarawa State, Nigeria
Authors: Olufemi Oladeinde Stephen , Joshua Magaji I. , Abraham Salamatu Ekpo
Published: July 2020

The output of cereal farmlands is imperative for sustainable global food security. Quantity of production from cereal croplands are partly a function of climatic elements and are connected to the pulses of climatic variation. Hence, this paper assessed temperature variability effect on rice production in Nasarawa State, Nigeria. Daily maximum and minimum temperature data were obtained from the Nigerian Meteorological Agency and converted into monthly averages while annual rice production data was obtained from the office of Nasarawa State’s Agricultural Development Programme. Acquired data were analysed using Linear Multiple Regression Model, coefficient of variation and spatial data analysis techniques. Although rice production in the State is being affected by the fluctuations in both minimum and maximum monthly temperature, the later poses grave concern for sustainability of rice production with a negative effect size of -3.145 and a coefficient value of -191,324.30 metric tons. This negative impact of maximum temperature fluctuations on rice production indicates that rice production in Nasarawa State is vulnerable to climate variability with increasing maximum temperature. LGAs in the south senatorial district has more favourable locations for rice production in comparison to those in the North and West districts given that less temperature fluctuation was observed in the former. Government and non-governmental institutions as well as individuals planning to establish rice farm project(s) in the study area should consider doing so in the South Senatorial District in order to avoid the adverse effect of temperature variability.
Association of Topical Minoxidil With Autosomal Recessive Woolly Hair/Hypotrichosis Caused by LIPH Pathogenic Variants
Authors: Taki Tomoki , Tanahashi Kana , Takeichi Takuya , Yoshikawa Takenori , Murase Yuya , Sugiura Kazumitsu , Akiyama Masashi
Published: July 2020

This nonrandomized clinical trial evaluates the association of topical minoxidil with hypotrichosis in patients with autosomal recessive woolly hair/hypotrichosis carrying LIPH pathogenic variants.
Self‐Healable and Recyclable Tactile Force Sensors with Post‐Tunable Sensitivity
Authors: Zhou Xiaozhuang , Zhang Xuan , Zhao Huaixia , Krishnan Baiju P. , Cui Jiaxi
Published: July 2020

It is challenging to post‐tune the sensitivity of a tactile force sensor. Herein, a facile method is reported to tailor the sensing properties of conductive polymer composites by utilizing the liquid‐like property of dynamic polymer matrix at low strain rates. The idea is demonstrated using dynamic polymer composites (CB/dPDMS) made via evaporation‐induced gelation of the suspending toluene solution of carbon black (CB) and acid‐catalyzed dynamic polydimethylsiloxane (dPDMS). The dPDMS matrices allow CB to redistribute to change the sensitivity of materials at the liquid‐like state, but exhibit typical solid‐like behavior and thus can be used as strain sensors at normal strain rates. It is shown that the gauge factor of the polymer composites can be easily post‐tuned from 1.4 to 51.5. In addition, the dynamic polymer matrices also endow the composites with interesting self‐healing ability and recyclability. Therefore, it is envisioned that this method can be useful in the design of various novel tactile sensing materials for many applications.
Realization of Epitaxial Thin Films of the Topological Crystalline Insulator Sr3SnO
Authors: Ma Yanjun , Edgeton Anthony , Paik Hanjong , Faeth Brendan D. , Parzyck Christopher T. , Pamuk Betül , Shang Shun‐Li , Liu Zi‐Kui , Shen Kyle M. , Schlom Darrell G. , Eom Chang‐Beom
Published: July 2020

Topological materials are derived from the interplay between symmetry and topology. Advances in topological band theories have led to the prediction that the antiperovskite oxide Sr3SnO is a topological crystalline insulator, a new electronic phase of matter where the conductivity in its (001) crystallographic planes is protected by crystallographic point group symmetries. Realization of this material, however, is challenging. Guided by thermodynamic calculations, a deposition approach is designed and implemented to achieve the adsorption‐controlled growth of epitaxial Sr3SnO single‐crystal films by molecular‐beam epitaxy (MBE). In situ transport and angle‐resolved photoemission spectroscopy measurements reveal the metallic and electronic structure of the as‐grown samples. Compared with conventional MBE, the used synthesis route results in superior sample quality and is readily adapted to other topological systems with antiperovskite structures. The successful realization of thin films of Sr3SnO opens opportunities to manipulate topological states by tuning symmetries via strain engineering and heterostructuring.
Crystallized Monolayer Semiconductor for Ohmic Contact Resistance, High Intrinsic Gain, and High Current Density
Authors: Peng Boyu , Cao Ke , Lau Albert Ho Yuen , Chen Ming , Lu Yang , Chan Paddy K. L.
Published: July 2020

The contact resistance limits the downscaling and operating range of organic field‐effect transistors (OFETs). Access resistance through multilayers of molecules and the nonideal metal/semiconductor interface are two major bottlenecks preventing the lowering of the contact resistance. In this work, monolayer (1L) organic crystals and nondestructive electrodes are utilized to overcome the abovementioned challenges. High intrinsic mobility of 12.5 cm2 V−1 s−1 and Ohmic contact resistance of 40 Ω cm are achieved. Unlike the thermionic emission in common Schottky contacts, the carriers are predominantly injected by field emission. The 1L‐OFETs can operate linearly from VDS = −1 V to VDS as small as −0.1 mV. Thanks to the good pinch‐off behavior brought by the monolayer semiconductor, the 1L‐OFETs show high intrinsic gain at the saturation regime. At a high bias load, a maximum current density of 4.2 µA µm−1 is achieved by the only molecular layer as the active channel, with a current saturation effect being observed. In addition to the low contact resistance and high‐resolution lithography, it is suggested that the thermal management of high‐mobility OFETs will be the next major challenge in achieving high‐speed densely integrated flexible electronics.
Photoactivatable Protherapeutic Nanomedicine for Cancer
Authors: Zhang Yan , Xu Cheng , Yang Xiangliang , Pu Kanyi
Published: July 2020

Therapeutic systems with site‐specific pharmaceutical activation hold great promise to enhance therapeutic efficacy while reducing systemic toxicity in cancer therapy. With operational flexibility, noninvasiveness, and high spatiotemporal resolution, photoactivatable nanomedicines have drawn growing attention. Distinct from traditional controlled release systems relying on the difference of biomarker concentrations between disease and healthy tissues, photoactivatable nanomedicines capitalize on the interaction between nanotransducers and light to either trigger photochemical reactions or generate reactive oxygen species (ROS) or heat effect to remotely induce pharmaceutical actions in living subjects. Herein, the recent advances in the development of photoactivatable protherapeutic nanoagents for oncology are summarized. The design strategies and therapeutic applications of these nanoagents are described. Representative examples of each type are discussed in terms of structure, photoactivation mechanism, and preclinical models. Last, potential challenges and perspectives to further develop photoactivatable protherapeutic nanoagents in cancer nanomedicine are discussed.
Energy Levels of Molecular Dopants in Organic Semiconductors
Authors: Li Peicheng , Lu Zheng‐Hong
Published: July 2020

The energy level alignments between hosts and dopants dictate many key physical processes such as charge transport and exciton formation, and thus the functionality and performance of organic semiconductor devices. Therefore, design and fabrication of high‐performance organic devices require knowledge of the energy offsets between hosts and dopants. Due to a typically low dopant concentration used in devices such as organic light‐emitting diodes and sometimes overlapping density of states, it is generally not possible to measure directly the energy offset in a doped system by photoemission technique. Here it is demonstrated that the energy offset between a host and a dopant in a doped system equals to that of its reciprocal heterojunction system. This opens the door for facile data collection. These directly measured offsets are also shown to be the same as the detrapping activation energies extracted from variable temperature charge transport modeling analysis. The energy level alignments between hosts and noncharge transfer dopants, charge transfer p‐type donors, and charge transfer n‐type acceptors are shown to exhibit the universal energy alignment rule for organic–organic heterojunction interfaces.
Heater‐Free and Substrate‐Independent Growth of Vertically Standing Graphene Using A High‐Flux Plasma‐Enhanced Chemical Vapor Deposition
Authors: Wu Zhiheng , Zhang Yongshang , Shen Yonglong , Zhang Wei , Shao Guosheng
Published: July 2020

Vertically standing graphene (VSG) films have demonstrated various appealing functionalities on the basis of excellent electrical/thermal conductivity and electrochemical/catalytic properties, owing to their unique morphology, preferable orientation of the basal planes, and adequate defects as effective catalytic sites. Most fabrication processes for VSG suffer from the disadvantage of high processing temperature, difficulty in structural control, or poor scalability, which limits their many potential applications. Herein, a scalable high‐flux plasma‐enhanced chemical vapor deposition system is designed, with streamlined magnetic field to enable high and uniform ion density over a spatially extended plasma flux, which facilitates large‐area deposition of structurally tuned VSG independent of substrate materials without additional heating, for the first time. The orientation, density, and the degree of order for the as‐fabricated VSG can be tailored through adjusting the plasma environment, which in turn affects crystallization mechanisms. Such low‐temperature synthesized VSG films are demonstrated as high‐performance anode in sodium ion batteries, achieving a high capacity retention of 86% after 2000 cycles at a current density of 1 A g−1. It is expected that the current VSG films would have great potential for electrochemical applications that request catalytic sites together with favorable conductivity for ions and electrons.
Efficient Modulation of Photonic Bandgap and Defect Modes in All‐Dielectric Photonic Crystals by Energetic Ion Beams
Authors: Du Guiqiang , Zhou Xiachen , Pang Chi , Zhang Kaiyuan , Zhao Yunpeng , Lu Guang , Liu Fen , Wu Ailing , Akhmadaliev Shavkat , Zhou Shengqiang , Chen Feng
Published: July 2020

The photonic bandgap and localization in photonic crystals can be effectively modulated by energetic ion beams owing to the induced modification of the thickness and refractive indices of the materials. In this work, the modulation of photonic bandgap and defect modes in 1D all‐dielectric photonic crystals is investigated theoretically and experimentally by using carbon (C5+) ion irradiation. It is found that the photonic bandgap and defect mode have a remarkable hypsochromic shift under the C5+ ion irradiation. The degree of the blueshift mainly depends on the reduction of the material thickness that is nearly proportional to the fluences of C5+ ions. The blueshift of the band edges and defect modes shows a step‐like behavior from transparency to opacification (near‐zero transmittance or high reflectance) or a converse trend. The work paves a new way to tailor the photonic crystals toward the development of novel devices with tunable specific wavelengths and wavebands.
Bromine Doping of MAPbI3 Films Deposited via Chemical Vapor Deposition Enables Efficient and Photo‐Stable Self‐Powered Photodetectors
Authors: Pammi Sri Venkata Narayana , Tran Van‐Dang , Maddaka Reddeppa , Eom Ji‐Ho , Jung Jang Su , Jeong Hyeon‐Myeon , Kim Moon‐Deock , Pecunia Vincenzo , Yoon Soon Gil
Published: July 2020

Hybrid lead‐halide perovskite photodetectors represent a highly promising technology, but long‐term operational stability under ambient conditions must be improved before these devices can be deployed in real‐world applications. In consideration of the relationship between film quality and device stability, this work explored photodetectors based on bromine‐doped CH3NH3PbI3 (i.e., CH3NH3PbI3−xBrx, MAPbI3−xBrx in short form) perovskite layers deposited via chemical vapor deposition (CVD). These layers have good compactness and no pinholes, hence they enable sandwich‐type photodetectors with high performance in self‐powered mode. Under 632 nm illumination, these photodetectors achieve a level of responsivity as high as 45 A/W, along with a specific detectivity of 1.15 × 1014 Jones and an external quantum efficiency of 8.84 × 103%. It is important to note that these photodetectors exhibit outstanding operational stability that is superior to that of their pure‐iodide (i.e., CH3NH3PbI3, MAPbI3 in short form) counterparts. When the MAPbI3−xBrx devices are stressed under simulated solar illumination in ambient air, their photoresponse is maintained to within 29% loss of the original value for more than 500 h, while the photoresponse of the MAPbI3 devices is reduced by 62%. The key figures of merit of the fabricated devices and their operational level of photostability are expected to create new avenues for future outdoor photodetector applications.
Color‐Tunable Circularly Polarized Luminescence with Helical Polyacetylenes as Fluorescence Converters
Authors: Zhao Biao , Gao Xiaobin , Lu Na , Deng Jianping
Published: July 2020

Circularly polarized luminescence (CPL) materials are currently drawing rapidly increasing interest. However, constructing color‐tunable CPL materials is still a big challenge, primarily due to the lack of simple, powerful, and universal preparation strategies. In this contribution, color‐tunable CPL emissions are easily realized by taking helical polyacetylenes as fluorescence converters. The investigated helical polyacetylenes are prepared by solution polymerization of a substituted acetylenic monomer with cholesteryl pendant. The prepared polymer exhibits dynamically reversible solvatochromism performance in different solvents, owing to the change of conjugated length of polymer main‐chains. More excitingly, when circularly polarized light with blue emission passes through the as‐prepared helical polyacetylene with different conjugated lengths, multicolor CPL emissions of cyan, green, and orange are obtained, with high dissymmetry factors (glum) in the range of 10−2–10−1. Also notably, neither any covalent nor noncovalent interaction is required during this CPL color‐tuning process. The present study provides a new insight for developing multicolor CPL materials.
Synthesis of Cyclopenta[b]indoles via a Formal [3+2] Cyclization of N‐Sulfonyl‐1,2,3‐triazoles and Indoles
Authors: Duan Shengguo , Zhang Wan , Hu Yuntong , Xu Ze‐Feng , Li Chuan‐Ying
Published: July 2020

Annulation of benzoxy‐tethered N‐sulfonyl‐1,2,3‐triazoles and indoles has been developed in this paper, providing an efficient and convenient access to valuable cyclopenta[b]indoles in moderate to good yields. α,β‐Unsaturated imine, which generated in situ from denitrogenation and 1,2‐OBz migration of triazole, provided three carbons for the formal [3+2] cyclization reaction for the first time.

magnified image
Heterojunction Photocatalysts Based on 2D Materials: The Role of Configuration
Authors: Su Qian , Li Yao , Hu Ran , Song Fang , Liu Siyuan , Guo Cuiping , Zhu Shenmin , Liu Wenbin , Pan Jian
Published: July 2020

Semiconductor photocatalysis is currently attracting tremendous attention as it holds great potential to address the issues of energy shortage and environmental pollution. 2D materials are excellent candidates for photocatalysis owing to their attractive structural and electronic properties. However, practical applications of 2D materials are still hindered due to limitations, such as fast electron–hole recombination and poor redox ability, both of which lead to low efficiency of photocatalytic reactions. Constructing a heterojunction is the most widely used strategy to solve these problems. In particular, heterojunctions composed of 2D materials interfaced with other semiconductors of different dimensionalities can integrate the respective advantages and mitigate the drawbacks of each component. Hence, this review focuses on the recent developments in the rational design of 2D material‐based heterojunction photocatalysts with different configurations. The synthetic strategies, physicochemical properties, component functions, photocatalytic mechanisms, and applications of these heterojunctions are systematically summarized. Emphasis is placed on correlations between photocatalytic performance and heterojunction configuration. Finally, the ongoing challenges and potential directions for future development of 2D material‐based heterojunction photocatalysts are also proposed.
Generation of Axially Polar Ferroelectricity in a Columnar Liquid Crystal Phase by Introducing Chirality
Authors: Akiyama Azumi , Jido Keita , Kohri Michinari , Taniguchi Tatsuo , Kishikawa Keiki
Published: July 2020

Axially polar ferroelectric columnar liquid crystals (AP‐FCLCs) are materials in which the molecules are self‐organized into axially polar columns and exhibit switching and holding of their polar directions. If the polar directions along the columnar axis can be controlled by using a nanosized electrode, AP‐FCLCs have the potential to realize ultrahigh‐density memory devices. Though switching polarities in columnar liquid crystal phases have been studied by many scientists, it remains difficult to realize bistable switching. In this study, it is found that replacement of the normal alkyl groups (decyl groups) with chiral groups ((S)‐citronellyl groups) in an N,N’‐bis(3,4,5‐trialkoxyphenyl)urea realizes perfect ferroelectricity in the rectangular columnar liquid crystal phase, and it is confirmed that the phase is an AP‐FCLC phase. The differences in the properties and molecular packing structures between the achiral and chiral urea compounds are investigated. Furthermore, the mechanism for achieving ferroelectricity by introduction of the chiral alkyl chains is postulated.
Achieving High Thermoelectric Performance by Introducing 3D Atomically Thin Conductive Framework in Porous Bi2Te2.7Se0.3‐Carbon Nanotube Hybrids
Authors: Li Shuankui , Wang Rui , Zhu Weiming , Chu Mihai , Huang Zhongyuan , Zhang Yanjun , Zhao Wenguang , Liu Fusheng , Luo Jun , Xiao Yinguo , Pan Feng
Published: July 2020

Fabricating thermoelectric (TE) materials with porous structure is an effective approach to reduce lattice thermal conductivity; however, the electrical conductivity is usually severely sacrificed. In this work, a high performance porous Bi2Te2.7Se0.3‐carbon nanotube (BTS‐CNTs) thermoelectric hybrid is prepared by introducing atomically thin BTS conductive networks on the BTS‐CNT interface, which simultaneously possess ultralow lattice thermal conductivity and high electrical conductivity. The 3D conductive framework built by atomically thin BTS layers on CNTs enables the creation of an intimate contact with bulk BTS and serves as a fast pathway of the electric conductivity, resulting in high electrical conductivity. Meanwhile, the phonon scattering around nanopore wall is greatly enhanced, and the lattice thermal conductivity is found to be as low as 0.19 W m−1 K−1, which is close to the minimal lattice thermal conductivity according to Debye–Cahill model. Consequently, the porous BTS/CNTs hybrid displays a high ZT value of about 1.2, which is 65% higher than that of fully dense pristine BTS. The present work demonstrates a novel and practical approach to design and fabricate high performance porous TE materials through an unconventional sacrificial template method.
Microgravity method in archaeological prospection: methodical comments on selected case studies from crypt and tomb detection
Authors: Pašteka Roman , Pánisová Jaroslava , Zahorec Pavol , Papčo Juraj , Mrlina Jan , Fraštia Marek , Vargemezis George , Kušnirák David , Zvara Ivan
Published: July 2020

Detailed and precise measurement of the Earth's gravity field (microgravity method) can be effectively used for the detection and quantification of subsurface voids and/or cavities. There exist a variety of successful applications of the microgravity method in near surface geophysics, namely in geotechnical, environmental and archaeological prospection. Using state‐of‐the‐art ‘microgal’ relative gravity meters, cavities of several metres in each dimension (positioned at a similar depth) can be detected and interpreted. Such objects produce negative anomalies with amplitudes of several tens of microGals (1 microGal = 10−8 m s−2). This contribution is focused on a methodological overview of the most important acquisition and processing steps in archaeological microgravimetry. In the processing of acquired gravimetrical data into a Bouguer anomaly, the so‐called building correction plays an important role, because the gravitational effect of building masses can produce false, usually negative anomalies. Several selected methods for quantitative interpretation are presented, these are based on depth estimation and density modelling. These interpretation methods give satisfactory results in the case of these type of negative anomalies that are caused by subsurface cavities. Microgravimetry can obtain good support from electromagnetic and electrical methods, mainly from ground penetrating radar and electrical resistivity tomography, respectively. Finally, we present successful case‐studies of microgravimetrical detection of crypts in various churches from the Middle Ages and period of Modern History, surveyed during recent decades in Slovakia and Czechia.
C−N, C−S and S−S Bond Cleavage by Rhodium PCcarbeneP Pincer Complexes
Authors: Tinnermann Hendrik , Young Rowan D.
Published: July 2020

Rhodium PCcarbeneP complexes 1‐L {L=PPh3, PPh2(C6F5)} react with isothiocyanate, carbodiimide and disulphide to enable C−S, C−N and S−S bond cleavage. The cleaved molecules are sequestered by the metal center and the pincer alkylidene linkage, forming η2‐coordinated sulfide or imide centered pincer complexes. When a C−S or S−S bond is cleaved, the resulting complexes can bridge two rhodium centers through sulphur forming dimeric complexes and eliminating a monodentate phosphine ligand.
Palladium‐Catalyzed Intramolecular Alder‐Ene Type Cycloisomerization Reactions
Authors: Yadav Sonu , Ramasastry S. S. V.
Published: July 2020

An overview of the recent literature on palladium‐catalyzed intramolecular Alder‐ene (IMAE) reaction of a variety of 1,n‐unsaturated systems is presented. The reaction which was first reported by Trost and Lautens provided an efficient alternative to the thermal or Lewis acid catalyzed cycloisomerizations involving ene‐type reaction. The IMAE cyclization of enynes and dienes has emerged as an important area and found significant applications in building up of complex molecular architectures and in the synthesis of several bioactive natural products. Since highly impactful reviews on this subject have covered the literature till 2015, this article focuses on summarizing the works subsequent to 2015.
Computer Vision Analysis of Reduced Interpersonal Affect Coordination in Youth With Autism Spectrum Disorder
Authors: Zampella Casey J. , Bennetto Loisa , Herrington John D.
Published: July 2020

Atypical social–emotional reciprocity is a core feature of autism spectrum disorder (ASD) but can be difficult to operationalize. One measurable manifestation of reciprocity may be interpersonal coordination, the tendency to align the form and timing of one's behaviors (including facial affect) with others. Interpersonal affect coordination facilitates sharing and understanding of emotional cues, and there is evidence that it is reduced in ASD. However, most research has not measured this process in true social contexts, due in part to a lack of tools for measuring dynamic facial expressions over the course of an interaction. Automated facial analysis via computer vision provides an efficient, granular, objective method for measuring naturally occurring facial affect and coordination. Youth with ASD and matched typically developing youth participated in cooperative conversations with their mothers and unfamiliar adults. Time‐synchronized videos were analyzed with an open‐source computer vision toolkit for automated facial analysis, for the presence and intensity of facial movements associated with positive affect. Both youth and adult conversation partners exhibited less positive affect during conversations when the youth partner had ASD. Youth with ASD also engaged in less affect coordination over the course of conversations. When considered dimensionally across youth with and without ASD, affect coordination significantly predicted scores on rating scales of autism‐related social atypicality, adaptive social skills, and empathy. Findings suggest that affect coordination is an important interpersonal process with implications for broader social–emotional functioning. This preliminary study introduces a promising novel method for quantifying moment‐to‐moment facial expression and emotional reciprocity during natural interactions.

Lay Summary

This study introduces a novel, automated method for measuring social–emotional reciprocity during natural conversations, which may improve assessment of this core autism diagnostic behavior. We used computerized methods to measure facial affect and the degree of affect coordination between conversation partners. Youth with autism displayed reduced affect coordination, and reduced affect coordination predicted lower scores on measures of broader social–emotional skills.
Plasmid Design for Tunable Two‐Enzyme Co‐Expression Promotes Whole‐Cell Production of Cellobiose
Authors: Schwaiger Katharina N. , Voit Alena , Dobiašová Hana , Luley Christiane , Wiltschi Birgit , Nidetzky Bernd
Published: July 2020

Catalyst development for biochemical cascade reactions often follows a “whole‐cell‐approach” in which a single microbial cell is made to express all required enzyme activities. Although attractive in principle, the approach can encounter limitations when efficient overall flux necessitates precise balancing between activities. This study shows an effective integration of major design strategies from synthetic biology to a coherent development of plasmid vectors, enabling tunable two‐enzyme co‐expression in E. coli, for whole‐cell‐production of cellobiose. An efficient transformation of sucrose and glucose into cellobiose by a parallel (countercurrent) cascade of disaccharide phosphorylases requires the enzyme co‐expression to cope with large differences in specific activity of cellobiose phosphorylase (14 U mg−1) and sucrose phosphorylase (122 U mg−1). Mono‐ and bicistronic co‐expression strategies controlling transcription, transcription‐translation coupling or plasmid replication are analyzed for effect on activity and stable producibility of the whole‐cell‐catalyst. A key role of bom (basis of mobility) for plasmid stability dependent on the ori is reported and the importance of RBS (ribosome binding site) strength is demonstrated. Whole cell catalysts show high specific rates (460 µmol cellobiose min−1 g−1 dry cells) and performance metrics (30 g L−1; ∼82% yield; 3.8 g L−1 h−1 overall productivity) promising for cellobiose production.
Advances in Cell‐Free Biosensors: Principle, Mechanism, and Applications
Authors: Zhang Liyuan , Guo Wei , Lu Yuan
Published: July 2020

Synthetic biology has promoted the development of biosensors as tools for detecting trace substances. In the past, biosensors based on synthetic biology have been designed on living cells, but the development of cell biosensors has been greatly limited by defects such as genetically modified organism problem and the obstruction of cell membrane. However, the advent of cell‐free synthetic biology addresses these limitations. Biosensors based on the cell‐free protein synthesis system have the advantages of higher safety, higher sensitivity, and faster response time over cell biosensors, which make cell‐free biosensors have a broader application prospect. This review summarizes the workflow of various cell‐free biosensors, including the identification of analytes and signal output. The detection range of cell‐free biosensors is greatly enlarged by different recognition mechanisms and output methods. In addition, the review also discusses the applications of cell‐free biosensors in environmental monitoring and health diagnosis, as well as existing deficiencies and aspects that should be improved. In the future, through continuous improvement and optimization, the potential of cell‐free biosensors will be stimulated, and their application fields will be expanded.
Simulated model of RAPID concept: highlighting innate inflammation and liver regeneration
Authors: Shi J H , Yan X , Zhang S J , Line P D
Published: July 2020

Background

The resection and partial liver segment II/III transplantation with delayed total hepatectomy (RAPID) concept is a novel transplantation technique for removal of non-resectable liver tumours. The aim of this study was to establish a simulated RAPID model to explore the mechanism involved in the liver regeneration.

Methods

A RAPID model was created in rats involving cold ischaemia and reperfusion of the selected future liver remnant (FLR), portal vein ligation, followed by resection of the deportalized lobes in a second step. Histology, liver regeneration and inflammatory markers in RAPID-treated rats were compared with those in controls that underwent 70 per cent hepatectomy with the same FLR size. The effects of interleukin (IL) 6 and macrophage polarization on hepatocyte viability were evaluated in an in vitro co-culture system of macrophages and BRL hepatocytes.

Results

The survival rate in RAPID and control hepatectomy groups was 100 per cent. The regeneration rate was higher in the RAPID-treated rats, with higher levels of IL-6 and M1 macrophage polarization (P < 0·050). BRL hepatocytes co-cultured with M1 macrophages showed a higher proliferation rate through activation of the IL-6/signal transducer and activator of transcription 3/extracellular signal-regulated kinase pathway. This enhancement of proliferation was inhibited by tocilizumab or gadolinium trichloride (P < 0·050).

Conclusion

The surgical model provides a simulation of RAPID that can be used to study the liver regeneration profile. Surgical RelevanceThe mechanisms sustaining liver regeneration are a relevant field of research to reduce the ‘small for size’ liver syndrome when the future liver remnant is not adequate. Several surgical strategies have been introduced both for liver resection and transplant surgery, mostly related to this issue and to the scarcity of grafts, among these the RAPID concept involving the use of an auxiliary segment II/III donor liver that expands to a sufficient size until a safe second-stage hepatectomy can be performed. Understanding the mechanisms and pitfalls of the liver regeneration profile may help in tailoring surgical strategies and in selecting patients. In this experimental model the authors investigated liver histology, regeneration and inflammatory markers in RAPID-treated rats.
Differences in the amplitude of low‐frequency fluctuation between methamphetamine and heroin use disorder individuals: A resting‐state fMRI study
Authors: Liu Yan , Zhu Jia , Li Qiang , Wang Yarong , Li Yongbin , Chen Jiajie , Dang Shan , Chen Jing , Shi Hong , Xue Jiuhua , Li Wei , Wang Wei
Published: July 2020

Introduction

Methamphetamine has surpassed heroin as the most popular abused drug in China. Although the use of both heroin and methamphetamine leads to use disorders through dysfunction of the dopamine pathway, the incidence of psychiatric disorder caused by methamphetamine abuse is higher than the incidence of psychiatric disorder caused by heroin abuse. The difference in resting‐state function between heroin use disorder (HUD) and methamphetamine use disorder (MAUD) and the relationship between resting‐state function and psychiatric disorder related to MAUD are unknown.

Methods

In the present study, 21 male individuals with MAUD, 21 demographically matched individuals with HUD, and 21 normal controls (NC) were recruited. The amplitude of low‐frequency fluctuation (ALFF) during resting‐state brain function was measured by magnetic resonance imaging. Psychiatric status was evaluated by the Symptom Checklist‐90 (SCL90).

Results

Individuals with MAUD had increased SCL90 scores compared to those of the NC for anxiety, paranoia, and additional items, and the hostility score was significantly increased compared to that of individuals with HUD. There is no significant difference between HUD and NC individuals. Individuals with MAUD had increased ALFF compared to those of the NC for thalamus, right postcentral, and right inferior temporal gyri, but a decreased ALFF in the cerebellum. Individuals with HUD had significantly increased ALFF compared to those of the NC for left middle frontal gyrus but a decreased ALFF in the left postcentral gyrus. Individuals with MAUD had significantly increased ALFF compared to those of the HUD for thalamus, the right inferior temporal, and bilateral postcentral gyri, and the ALFF of cerebellum and left middle frontal was significantly increased.

Conclusions

Methamphetamine can induce more serious psychiatric disorders than heroin. The resting‐state function involved in mood adjustment, the auditory, and memory‐related brain regions may affect psychotic symptoms related to MAUD.
Modulated radiation protocol achieves marked reduction of radiation exposure for chronic total coronary occlusion intervention
Authors: Werner Gerald S. , Yaginuma Kenji , Koch Matthias , Tischer Karlheinz , Silber Martin , Werner Juliane , Keuser Thomas , Moehlis Hiller
Published: July 2020

Objective

To evaluate the feasibility of a new acquisition protocol to reduce radiation exposure.

Background

Percutaneous coronary interventions (PCI) for chronic total coronary occlusions (CTO) are characterized by the highest radiation exposure among PCI procedures.

Methods

We analyzed 552 consecutive CTO procedures between January 2018 and October 2019. After 366 procedures (Group 1) a modified radiation acquisition protocol was implemented for the subsequent 186 procedures (Group 2). Besides a low fluoroscopy frame rate of 6/s and cine frame rate of 7.5/s for both groups, additional modifications consisted of increased copper filtering with lower entry dose in combination with a modified image postprocessing. Radiation exposure was assessed as air kerma (AK; mGy), and dose–area product (DAP; cGy*cm2).

Results

There was no significant difference in lesion or procedural complexity between the study groups with 46 and 43% of the procedures done via the retrograde approach. While fluoroscopy time remained similar (median: 32.7 vs. 34.3 min), the protocol modifications resulted in a drastic reduction of AK by 68% from 2,040 (1,321–3,339) mGy to 655 (415–1,113) mGy (p < .001) without affecting the procedural success rate. DAP was equally decreased by 71%. These considerable reductions were observed even in obese patients of BMI > 30. In Group 2, not a single procedure exceeded the 5 Gy threshold as compared to 10.4% in Group 1.

Conclusions

Radiation exposure decreased considerably with a new acquisition protocol without affecting procedure duration and success. These modifications were applicable also to patients with a high BMI.
Assessing the Effect of the Electron‐Beam Irradiation on Pd/Ga2O3 Catalyst under Ambient Pressure
Authors: Wang Yongzhao , Niu Yiming , Gao Tongtong , Liu Siyang , Zhang Bingsen
Published: July 2020

Introducing atmosphere in transmission electron microscope enables to directly observe the structural features of catalyst under working conditions. It offers the possibility to study the microstructural evolution and correlate real structures with catalytic properties at nano‐ or atomic‐scale during catalysis. However, the damages to catalyst derived from the high energy electron‐beam irradiation cannot be ignored and may lead to ambiguous conclusions, as the interaction between reactive gas molecules and active structures is only desired. Herein, the α‐Ga2O3 supported Pd catalyst was selected as a model to evaluate the potential effect of electron‐beam on the surface and interface structures, which directly affect the catalytic performance, at varied atmospheres, elevated temperatures and increased electron dose rate in ambient pressure. The results indicate that the supported Pd nanoparticles could be encapsulated by GaOx layer when the imaging electron dose rate is higher than 100 e/Å2s under reduction and oxidizing atmosphere. Either increasing the electron dose rate or elevating the temperature exacerbates the irradiation damage to α‐Ga2O3 support. This work was expected to evaluate the effect of electron dose rate to supported catalysts under chemical environments, and provide guidance for the investigation of in‐situ transmission electron microscopy under ambient pressure.
Synthesis of 2‐Organylchalcogenopheno[2,3‐b]pyridines from Elemental Chalcogen and NaBH4/PEG‐400 as a Reducing System: Antioxidant and Antinociceptive Properties
Authors: Peglow Thiago J. , Bartz Ricardo H. , Martins Carolina C. , Belladona Andrei L. , Luchese Cristiane , Wilhelm Ethel A. , Schumacher Ricardo F. , Perin Gelson
Published: July 2020

An alternative method to prepare 2‐organylchalcogenopheno[2,3‐b]pyridines was developed by the insertion of chalcogen species (selenium, sulfur or tellurium), generated in situ, into 2‐chloro‐3‐(organylethynyl)pyridines by using the NaBH4/PEG‐400 reducing system, followed by an intramolecular cyclization. It was possible to obtain a series of compounds with up to 93 % yield in short reaction times. Among the synthesized products, 2‐organyltelluropheno[2,3‐b]pyridines have not been described in the literature so far. Moreover, the compounds 2‐phenylthieno[2,3‐b]pyridine (3 b) and 2‐phenyltelluropheno[2,3‐b]pyridine (3 c) exhibited significant antioxidant potential in different in vitro assays. Further studies demonstrated that compound 3 b exerted an antinociceptive effect in acute inflammatory and non‐inflammatory pain models, thus indicating the involvement of the central and peripheral nervous systems on its pharmacological action. More specifically, our results suggest that the intrinsic antioxidant property of compound 3 b might contribute to attenuating the nociception and inflammatory process on local injury induced by complete Freund's adjuvant (CFA).
Evolution of a Metal‐Organic Framework into a Brønsted Acid Catalyst for Glycerol Dehydration to Acrolein
Authors: Li Xiaomin , Huang Liang , Kochubei Alena , Huang Jun , Shen Wei , Xu Hualong , Li Qiaowei
Published: July 2020

Metal−organic frameworks (MOFs) as solid acid catalysts provide active sites with definite structures. Here, Zr6‐based MOF‐808 and its derivatives were studied as catalysts for glycerol dehydration, the products of which (acrolein vs. acetol) are very sensitive to the nature of the catalytic acid sites. Evolving MOF‐808 into MOF‐808‐S with a 120 % increase in the number of Brønsted OH−/H2O coordinated to ZrIV and a vanished Lewis acidity by steam treatment, the post‐synthetically modified catalyst presented 100 % conversion of glycerol, 91 % selectivity to acrolein, and 0 % selectivity to acetol within the active window. Real‐time analysis of the product composition indicated the in situ MOF structural evolution. Overall, the specific MOF‐substrate interaction characterized by the probe reaction provides more understandings on the structural evolution of the MOFs and their impact on the performance as solid acid catalysts.
Strong, Reusable, and Self‐Healing Lignin‐Containing Polyurea Adhesives
Authors: Liu Weifeng , Fang Chang , Chen Fenting , Qiu Xueqing
Published: July 2020

Reusable, self‐healable, removable, and strong bio‐based polyurea adhesives were successfully synthesized via partially substituting polyetheramine with polyetheramine‐grafted lignin and introducing a chain extender containing dynamic disulfide bonds. The polyetheramine‐grafted lignin endowed the polyurea adhesives with significantly enhanced adhesion strength on either metal or wood substrates by introducing intensive hydrogen bonding interactions; the dynamic disulfide bonds played a key role in the excellent self‐healing and reusable performance. The thermostability of polyurea adhesives was also improved by introducing lignin. This work provides a novel approach for the high‐value utilization of low‐cost lignin in recyclable adhesives with excellent comprehensive performance.