bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous Optimization of Phase and Morphology of CsPbBr3 Films via Controllable Ostwald Ripening by Ethylene Glycol Monomethylether/Isopropanol Bi‐Solvent Engineering
Authors: Meng Qingxiao , Feng Jianyong , Huang Huiting , Han Xiaopeng , Zhu Zhi , Yu Tao , Li Zhaosheng , Zou Zhigang
Published: April 2020

Both phase and morphology of perovskite films are very important for high‐performance optoelectronic devices. Although a two‐step method based on CsBr ethylene glycol monomethylether (EGME) solution can prepare pure‐phase CsPbBr3 films, they have a poor morphology due to excessive Ostwald ripening. Herein, a bi‐solvent engineering strategy is demonstrated to simultaneously optimize phase and morphology of CsPbBr3 films in a two‐step solution method, which uses the bi‐solvents of EGME and isopropanol (IPA) instead of EGME for CsBr solution at the second step. Optimizing the volume ratio of bi‐solvents and immersion time can control the Ostwald ripening effectively and result in pure‐phase, compact, and smooth CsPbBr3 films. Finally, the prepared films are applied to perovskite solar cells (PSCs) with a structure of fluorine‐doped tin oxide (FTO)/compact TiO2 (c‐TiO2)/CsPbBr3/carbon. In comparison with EGME, the champion power conversion efficiency (PCE) of devices from EGME/IPA bi‐solvents increases from 3.57% to 7.29% owing mainly to higher coverage, smoother surface, and lower trap density of CsPbBr3 films from EGME/IPA bi‐solvents. This work provides a simple and efficient method for the preparation of high‐quality CsPbBr3 films.
Highly Efficient Microscopic Charge Transport within Crystalline Domains in a Furan‐Flanked Diketopyrrolopyrrole‐Based Conjugated Copolymer
Authors: Tanaka Hisaaki , Kawamura Shinya , Sonar Prashant , Shimoi Yukihiro , Do Thu Trang , Takenobu Taishi
Published: April 2020

Elucidating the interrelation between the molecular structure and charge transport properties in conjugated polymer thin films is an essential issue in developing the design principle of high‐performance polymer materials for application in organic electronics. In particular, the backbone planarity is suggested to be a key element that governs the transport performance, especially in recently developed donor–acceptor (D–A)‐type copolymers exhibiting high mobility, whereas the direct evaluation of the intrinsic transport performance, usually realized only within the small crystalline domains, is difficult by using conventional macroscopic measurements. Here, it is demonstrated that a D–A type copolymer, PDPPF‐DTT, which consists of furan‐flanked diketopyrrolopyrrole (DPP) and dithienothiophene (DTT) units in the conjugated backbone, exhibits a highly efficient charge transport performance within the crystalline domains with a remarkably low activation energy of less than 8 meV, based on microscopic measurements using field‐induced electron spin resonance spectroscopy. This high transport performance is primarily caused by the high backbone planarity realized by introducing furan‐flanked DPP and fused dithienothiophene units, which is demonstrated from the density functional theory calculations. This result provides a microscopic indication of the effectiveness of the present molecular design to produce a planar backbone and realize highly efficient charge transport performance.
Multi‐Caged IrOx for Facile Preparation of “Six‐in‐One” Nanoagent for Subcutaneous and Lymphatic Tumors Inhibition against Recurrence and Metastasis
Authors: Zhen Wenyao , Liu Yang , Zhang Mengchao , Hu Wenxue , Wang Wei , Jia Xiaodan , Jiang Xiue
Published: April 2020

Single nanocarriers with intrinsic characteristics of diagnosis, effective therapy against solid malignancies with fatal metastasis, and tumor microenvironment regulation are promising in construction of a simple and effective multimode nanotheranostic system. Herein, multi‐caged IrOx nanocarriers are fabricated by direct thermal hydrolysis strategy, which exhibit good sono‐photodynamic response, outstanding gemstone spectral computed tomography, and photoacoustic (PA) imaging capabilities, universal loading, and pinpoint drug release properties. As a proof of concept, a gemstone spectral computed tomography/PA/fluorescence imaging–guided oxygen self‐sufficient sono‐photo‐chemotherapy nanoagent by simple loading of doxorubicin is constructed. The remarkable synergistic therapy and excellent hypoxia releasing capabilities can remove both subcutaneous and sentinel lymph nodes metastasis tumors, and effectively suppress tumor recurrence and lung metastasis, thus greatly prolonging survival time. The study provides an attractive candidate to construct a “six‐in‐one” (tri‐modal therapies and three imaging modalities) tumor theranostic system.
Heavy Water Additive in Formamidinium: A Novel Approach to Enhance Perovskite Solar Cell Efficiency
Authors: Solanki Ankur , Tavakoli Mohammad Mahdi , Xu Qiang , Dintakurti Sai S. H. , Lim Swee Sien , Bagui Anirban , Hanna John V. , Kong Jing , Sum Tze Chien
Published: April 2020

Heavy water or deuterium oxide (D2O) comprises deuterium, a hydrogen isotope twice the mass of hydrogen. Contrary to the disadvantages of deuterated perovskites, such as shorter recombination lifetimes and lower/invariant efficiencies, the serendipitous effect of D2O as a beneficial solvent additive for enhancing the power conversion efficiency (PCE) of triple‐A cation (cesium (Cs)/methylammonium (MA)/formaminidium (FA)) perovskite solar cells from ≈19.2% (reference) to 20.8% (using 1 vol% D2O) with higher stability is reported. Ultrafast optical spectroscopy confirms passivation of trap states, increased carrier recombination lifetimes, and enhanced charge carrier diffusion lengths in the deuterated samples. Fourier transform infrared spectroscopy and solid‐state NMR spectroscopy validate the N–H2 group as the preferential isotope exchange site. Furthermore, the NMR results reveal the induced alteration of the FA to MA ratio due to deuteration causes a widespread alteration to several dynamic processes that influence the photophysical properties. First‐principles density functional theory calculations reveal a decrease in PbI6 phonon frequencies in the deuterated perovskite lattice. This stabilizes the PbI6 structures and weakens the electron–LO phonon (Fröhlich) coupling, yielding higher electron mobility. Importantly, these findings demonstrate that selective isotope exchange potentially opens new opportunities for tuning perovskite optoelectronic properties.
Tellurium: A High‐Volumetric‐Capacity Potassium‐Ion Battery Electrode Material
Authors: Dong Shuai , Yu Dandan , Yang Jie , Jiang Li , Wang Jiawei , Cheng Liwei , Zhou Yan , Yue Honglei , Wang Hua , Guo Lin
Published: April 2020

Currently, exploring high‐volumetric‐capacity electrode materials that allow for reversible (de‐)insertion of large‐size K+ ions remains challenging. Tellurium (Te) is a promising alternative electrode for storage of K+ ions due to its high volumetric capacity, confirmed in lithium‐/sodium‐ion batteries, and the intrinsic good electronic conductivity. However, the charge storage capability and mechanism of Te in potassium‐ion batteries (KIBs) have not been unveiled until now. Here, a novel K–Te battery is constructed, and the K+‐ion storage mechanism of Te is revealed to be a two‐electron conversion‐type reaction of 2K + Te ↔ K2Te, resulting in a high theoretical volumetric capacity of 2619 mAh cm−3. Consequently, the rationally fabricated tellurium/porous carbon electrodes deliver an ultrahigh reversible volumetric capacity of 2493.13 mAh cm−3 at 0.5 C (based on Te), a high‐rate capacity of 783.13 mAh cm−3 at 15 C, and superior long‐term cycling stability for 1000 cycles at 5 C. This excellent electrochemical performance proves the feasibility of utilizing Te as a high‐volumetric‐capacity active material for storage of K+ ions and will advance the practical application of KIBs.
Reconfigurable Metasurfaces for Frequency Selective Absorption
Authors: Jeong Heijun , Le Dinh Hai , Lim Daecheon , Phon Ratanak , Lim Sungjoon
Published: April 2020

Metasurfaces can provide novel functionality for absorbing electromagnetic waves through a periodic array of inductive/capacitive resonators by controlling the material's permittivity and permeability. This attractive characteristic makes them widely applicable to various electromagnetic applications. However, conventional metasurfaces are dispersive and suffer from a narrow bandwidth with uncontrollable and unchangeable functions because the effective permittivity and permeability are tailored to a certain resonance frequency. Therefore, many studies have focused on how to increase the absorption frequency bandwidth and control the absorption frequency by using reconfigurable metasurfaces. This paper presents a report on the most recent progress in the realization of reconfigurable metasurfaces based on advanced materials for frequency‐selective absorption in the microwave, millimeter‐wave, sub‐terahertz, terahertz, and visible ranges. Furthermore, their tuning ratios for different advanced materials and spectra are summarized and compared. This progress report provides guidelines for the material selection for and the design of reconfigurable metasurfaces.
Rapid Microwave‐Annealing Process of Hybrid Perovskites to Eliminate Miscellaneous Phase for High Performance Photovoltaics
Authors: Chen Qing , Ma Taotao , Wang Fangfang , Liu You , Liu Sizhou , Wang Jungan , Cheng Zhengchun , Chang Qing , Yang Rong , Huang Wenchao , Wang Lin , Qin Tianshi , Huang Wei
Published: April 2020

Rapid processing technologies of perovskite solar cells (PSCs) offer an exciting approach to raise the rate of production. Herein, a rapid microwave‐annealing process (MAP) is reported to replace the traditional hotplate annealing process (HAP) and the processing period of perovskite is reduced to less than 1 min. Benefiting from the penetrability and simultaneity of microwave irradiation, the MAP method can effectively eliminate miscellaneous phases and thus achieve >1 µm large‐size crystal grains in perovskite films. These MAP treated perovskite films exhibit pure crystalline phase, long charge‐carrier lifetime, and low defect density, which can substantially improve the PSC efficiency without requiring an additional enhancer/passivation layer. The inverted planar PSCs present enhanced power conversion efficiency from 18.33% (HAP) to 21.59% (MAP) and good stability of >1000 h lifetime without encapsulation under ambient conditions. In addition, MAP can be applied to a large‐size (10 cm × 10 cm) perovskite film fabrication as well as a broader tolerance in environmental temperature and precursor concentration, making it a reliable method for repeatably practical fabrication of perovskite photovoltaics.
Total Syntheses of (−)‐Minovincine and (−)‐Aspidofractinine through a Sequence of Cascade Reactions
Authors: Varga Szilárd , Angyal Péter , Martin Gábor , Egyed Orsolya , Holczbauer Tamás , Soós Tibor
Published: April 2020

We report 8‐step syntheses of (−)‐minovincine and (−)‐aspidofractinine using easily available and inexpensive reagents and catalyst. A key element of the strategy was the utilization of a sequence of cascade reactions to rapidly construct the penta‐ and hexacyclic frameworks. These cascade transformations included organocatalytic Michael‐aldol condensation, a multistep anionic Michael‐SN2 cascade reaction, and Mannich reaction interrupted Fischer indolization. To streamline the synthetic routes, we also investigated the deliberate use of steric effect to secure various chemo‐ and regioselective transformations.
Silica aerogel/epoxy nanocomposites: Mechanical, vibrational, and morphological properties
Authors: Albooyeh Alireza , Bayat Mohammadhosein , Rafieian Pouria , Dadrasi Ali , Khatibi Mohammad Mahdi
Published: April 2020

The present study was an attempt to examine the effects that adding silica aerogel (SA) nanoparticles to epoxy would exert on its mechanical, vibrational, and morphological properties. Neat epoxy was consecutively combined with 1, 2, and 4 wt% of SA nanoparticles. A number of tests of mechanical properties were then performed on the samples, including tests of tensile, bending, compressive, dynamic mechanical thermal, hardness, and Izod impact. Vibration and water uptake tests were also conducted on the samples. The highest modulus and strength values were found in the nanocomposite sample with 4 wt% of SA, and the highest toughness and elongation values were detected in the sample with 1 wt% of SA. Furthermore, adding the SA nanoparticles to the epoxy improved the energy absorption and hardness of the epoxy matrix. The findings from the tests of dynamic mechanical thermal and vibration properties demonstrated that, with an increase in the nanoparticles content in the samples, the values of storage modulus and natural frequency increased while the values of tan δ and damping ratios decreased. A comparison between the values of natural frequency from the vibration test and the values from the Euler–Bernoulli beam theory showed a good agreement between the theoretical and experimental results.
The decision to check in multialternative choices and limited sensitivity to default
Authors: Roth Yefim
Published: April 2020

Given the rapid proliferation of smartphone applications and data aggregation websites, in many situations people can use decision aids to guide their choices. For example, they may consider whether to use a navigation device to check the fastest route or whether to use a price comparison website to find the cheapest deal. In what circumstances will subjects use a costly comparison decision aid (which I refer to as “checking”) to choose for them? In six studies, I investigate the impact of the number of available alternatives and checking's attractiveness on the decision to check. While at first increasing the attractiveness of checking led to higher checking rates, a further increase in the number of available alternatives (and thus checking's attractiveness) did not increase the checking rate. Surprisingly, even when checking had a 40% higher expected value compared with not checking, the observed checking rate was below 45%, contrary to risk and ambiguity aversion predictions. Furthermore, labeling the checking alternative as the default had no impact on its choice rate. I find large individual differences in decisions to check. Surprisingly, subjects' initial decisions had high predictive power over their subsequent checking rates, even after 100 trials with full feedback. I propose two simple learning models that capture well the aggregated results.
The association between legalization of recreational marijuana use and birth outcomes in Colorado and Washington state
Authors: Siega‐Riz Anna Maria , Keim‐Malpass Jessica , Lyons Genevieve R. , Alhusen Jeanne
Published: April 2020

Objective

To identify trends in birth outcomes that may be associated with legalization of recreational marijuana which occurred in 2013 using vital records from Colorado and Washington states for the period of 2008–2016.

Methods

Data were from birth certificates of live births (between 22 and 44 weeks gestation) of which there were 576,369 singleton births included for Colorado and 771,547 for Washington State. Outcomes included preterm birth defined as <37 completed weeks of gestation; small for gestational age (SGA) defined using <10th percentile birthweight z‐score; and birth prevalence of congenital anomalies defined using a variable from the birth certificate that indicated any major defect. The outcomes of interest were analyzed using a change‐point approach to logistic regression adjusting for maternal socio‐demographics, body mass index, smoking, and infant sex.

Results

There was evidence of an increased birth prevalence of congenital anomalies in both Colorado and Washington State when comparing prevalence before and after legalization. Only in Colorado did we observe an increase in preterm births post legalization, and there was no association with fetal growth in either state.

Conclusion

This time trend analysis indicates that the birth prevalence of all congenital anomalies combined in Washington and Colorado has increased in parallel with the timing of legalization of marijuana in those two states. However, this finding can only generate hypotheses as no pregnancy exposure information for marijuana was available in this dataset. More research is needed on the effect of marijuana use on birth outcomes.
Water‐Soluble Polymeric Probes for the pH‐Tunable Fluorometric Detection of Hydrogen Peroxide
Authors: Annisa Tiara Nur , Lee Hyung‐il
Published: April 2020

Hydrogen peroxide (H2O2) is an important reactive oxygen species (ROS) that plays a significant role in many biological systems. A new water‐soluble polymeric probe appended with pyrene and boronic acid groups was designed and synthesized for the detection of H2O2. Glycidyl methacrylate (GMA) and N,N‐dimethylacrylamide (DMA) were copolymerized by reversible addition‐fragmentation chain‐transfer (RAFT) polymerization to yield poly(glycidyl methacrylate‐co‐dimethylacrylamide) [p(GMA‐co‐DMA)](P1). The subsequent ring‐opening reaction between the secondary amine of (3‐((pyren‐1‐ylmethyl)amino)phenyl)boronic acid with the epoxide unit of P1 yielded a target polymer, P2. In the presence of H2O2, the phenyl boronic acid group of P2 transformed to a phenol group, which was accompanied by turn‐off fluorescence. P2 also exhibited pH‐tunable detection sensitivity. This polymeric probe is anticipated to promote the development of stimuli‐responsive water‐soluble polymers with fluorescence‐sensing behaviors.
Sponsorship of oncology clinical trials in the United States according to age of eligibility
Authors: Neel Dylan V. , Shulman David S. , Ma Clement , Bourgeois Florence , DuBois Steven G.
Published: April 2020

Background

The sponsorship mix of trials relevant to young people with cancer has not been reported. Understanding this sponsorship mix may have implications for policies and regulations related to pediatric cancer drug development.

Methods

We analyzed sponsorship of interventional trials first opened in the United States from 2007 to 2018 using the ClinicalTrials.gov registry. A total of 51 781 trials across non‐oncology disciplines and 18 431 oncology trials were classified according to lower age of eligibility (≥18 years vs < 18 years). Studies were stratified according to sponsorship (industry vs non‐industry). Trial characteristics were compared by sponsorship category. Trends in sponsorship were tracked over time.

Results

Within oncology trials for patients ≥ 18 years, sponsorship was 33% industry and 67% non‐industry. Among oncology trials that included patients < 18 years, sponsorship was 16.6% industry and 83.4% non‐industry (P < .001). 15.5% of industry‐sponsored trials in non‐oncology disciplines included patients < 18 years, whereas only 5.2% of industry‐sponsored oncology trials were open to patients < 18 years (P < .001). Relative to trials with non‐industry sponsors, there was a statistically significant increase in industry sponsorship of oncology trials that included patients < 18 years over time (P < .001). Trial characteristics differed significantly according to sponsor type regardless of age of eligibility.

Conclusions

Interventional oncology trials that include patients < 18 years are less likely to be industry‐sponsored compared to oncology trials exclusively in patients ≥ 18 years. Compared to other medical disciplines, a smaller proportion of industry‐sponsored oncology trials included patients < 18 years. Trial sponsorship is associated with differential trial characteristics, such as trial duration and number of patients enrolled, regardless of age.
Detection and discrimination of Carica papaya fungi through the analysis of volatile metabolites by gas chromatography and analysis of variance‐principal component analysis
Authors: Terra Larissa R. , Queiroz Sonia C.N. , Terao Daniel , Ferreira Márcia M.C.
Published: April 2020

Conventional detection and identification of the fungi causing postharvest diseases in fruits are time‐consuming, laborious, and can only be performed after the manifestation of symptoms. In this work, an alternative method based on headspace analysis, and which allows the early detection of fungi species frequently found papaya fruit, is presented. Volatile compounds of four in vitro fungi cultures (Alternaria alternata, Colletotrichum gloeosporioides, Fusarium solani, and Lasiodiplodia theobromae) were extracted using solid‐phase microextraction (SPME) and analyzed by gas chromatography coupled with mass spectrometry. The resulting chromatographic fingerprints were explored by conventional principal component analysis (PCA) and analysis of variance (ANOVA)–PCA. Decomposition of the original matrix, according to the factors proposed in the experimental design, by ANOVA before applying the PCA improved the distinction of the control and fungi samples. The main chromatographic peaks referring to the metabolites produced by each species were successfully identified using the proposed analysis. A primary alcohol with five carbons and phenylethyl alcohol were observed in all fungi species and so could be used as an indicative of postharvest disease. Although unique metabolites were detected for all fungi species, only those from C. gloeosporioides and another from F. solani could be surely identified, such as thymolmethyl and 3,6‐dimethylhept‐6‐en‐4‐yn‐3‐ol, respectively. The in vitro results obtained are promising, and it is expected that the biomarkers detected in this work will be useful in future development of methods for the early detection and classification of papaya fungi species.
Electrocatalytic Proton Reduction by a Cobalt Complex Containing a Proton‐Responsive Bis(alkylimdazole)methane Ligand: Involvement of a C−H Bond in H2Formation
Authors: Ghosh Pradip , de Vos Sander , Lutz Martin , Gloaguen Frederic , Schollhammer Philippe , Moret Marc‐Etienne , Klein Gebbink Robertus J. M.
Published: April 2020

Homogeneous electrocatalytic proton reduction is reported using cobalt complex [1](BF4)2. This complex comprises two bis(1‐methyl‐4,5‐diphenyl‐1H‐imidazol‐2‐yl)methane (HBMIM) ligands that contain an acidic methylene moiety in their backbone. Upon reduction of [1](BF4)2by either electrochemical or chemical means, one of its HBMIMligands undergoes deprotonation under the formation of dihydrogen. Addition of a mild proton source (acetic acid) to deprotonated complex [2](BF4) regenerates protonated complex [1](BF4)2. In presence of acetic acid in acetonitrile solvent [1](BF4)2shows electrocatalytic proton reduction with akobsof ≈200 s−1at an overpotential of 590 mV. Mechanistic investigations supported by DFT (BP86) suggest that dihydrogen formation takes place in an intramolecular fashion through the participation of a methylene C−H bond of the HBMIMligand and a CoII−H bond through formal heterolytic splitting of the latter. These findings are of interest to the development of responsive ligands for molecular (base)metal (electro)catalysis.
Dirhodium(II)‐Catalyzed C(sp2)−H Azidation of Benzaldehydes
Authors: Wang Yi , Fang Zaixiang , Chen Xiaochuan , Wang Yuanhua
Published: April 2020

Invited for the cover of this issue is the group of Yuanhua Wang at Sichuan University. The image depicts the reported dirhodium complexes depicted as Chinese lanterns. Read the full text of the article at 10.1002/chem.201905855.
Autonomous Machines or Complex Automats – Who is Responsible for Al Algorithms?
Authors: Neupert Michael
Published: April 2020

Zu den fundamentalen Fragen, die im Zuge der Entwicklung hin zur Industrie 4.0 diskutiert werden, gehört die nach der Verantwortung für Maschinen. Die innerjuristische Diskussion darüber leidet unter dem unklaren Begriff der künstlichen Intelligenz und der Faszination über die Schöpfung punktuell sehr großer technischer Leistungsfähigkeit, obwohl ein blitzschneller Zugriff auf eine riesige Informationsmenge oder das Ermitteln von bislang unentdeckten Korrelationen zwischen Einzelphänomenen keine Anzeichen für das Auftreten des Übermenschen sind. Techniker stehen umgekehrt verwirrt vor den Differenzierungen, mit denen Juristen sich der Frage nach Verantwortung nähern. Der vorliegende Beitrag versucht einen Brückenschlag, um den interdisziplinären Dialog zu stärken.
Toward a domain‐specific language for scientific workflow‐based applications on multicloud system
Authors: Cordasco Gennaro , D'Auria Matteo , Negro Alberto , Scarano Vittorio , Spagnuolo Carmine
Published: April 2020

The cloud computing paradigm has emerged as the backbone of modern price‐aware scalable computing systems. Many cloud service models are competing to become the leading doorway to access the computational power of cloud providers. Recently, a novel service model, called function‐as‐a‐service (FaaS), has been proposed, which enables users to exploit the cloud computational scalability, left out the configuration and management of huge computing infrastructures. This article discloses Fly, a domain‐specific language, which aims at reconciling cloud and high‐performance computing paradigms adopting a multicloud strategy by providing a powerful, effective, and pricing‐efficient tool for developing scalable workflow‐based scientific applications by exploiting different and at the same time FaaS cloud providers as computational backends in a transparent fashion. We present several improvements of the Fly language, as well as a new enhanced version of a source‐to‐source compiler, which currently supports Symmetric Multiprocessing, Amazon AWS, and Microsoft Azure backends and translation of functions in Java, JavaScript, and Python programming languages. Furthermore, we discuss a performance evaluation of Fly on a popular benchmark for distributed computing frameworks, along with a collection of case studies with an analysis of their performance results and costs.
Is Strip‐till a Useful Soil Management Tool for Wisconsin Corn and Soybean Production?
Authors: Potratz Derek J. , Mourtzinis Spyridon , Gaska John , Lauer Joseph , Arriaga Francisco J. , Conley and Shawn P.
Published: April 2020

Alleviation of cold, wet, and compacted soils is of great importance for earlier planting that can lead to improved yield in short growing season environments. Strip‐till adoption in corn has increased as a sustainable means to improve soil conditions and yield; however, the response of soybean to strip‐till has been less consistent. The objectives of this research were to (1) quantify the effect of strip‐till, row spacing (soybean only), crop rotation (corn only), fertilizer placement, and in‐furrow fungicide on corn and soybean plant population, canopy coverage, and grain or seed yield; (2) evaluate strip‐till, row spacing, fertilizer placement, and in‐furrow fungicide on soil temperature and penetration resistance; and (3) determine best management recommendations for strip‐till use in Wisconsin corn and soybean production systems. Earn 0.5 CEUs in Soil & Water Management by reading this article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/798.
Energy‐efficient cluster manager‐based cluster head selection technique for communication networks
Authors: S Amutha , B Kannan , J M Kanagara
Published: April 2020

The Mobile Adhoc Network (MANET) is a distributed network without any standard infrastructure. In MANETs, several nodes in the network are grouped by which they can communicate with each other. Clustering is a grouping of mobiles nodes performs the communication process by means of optimal usage of available bandwidth and high network throughput. Several clustering schemes exist, but they suffer from the consumption of energy because of the cluster head's workload and increase in the number of clusters. In this paper, we propose a cluster manager‐based cluster head selection (CMBCH) scheme to overcome the energy problems and leverage CH workload. CMBCH consists of two components, such as cluster manager (CM) and cluster head (CH). The CM takes the responsibility of controlling and monitoring of nodes activities. The CH leads and performing packet transfer among the nodes in the network. At this stage, when current CH energy level is drained, CM elects the corresponding node with high energy level and the new, as well as old CH activities, are simultaneously stored by CM. To prove the proposed scheme efficiency, a simulation experiment was conducted for 20 to 100 nodes under the AODV routing protocol. The network parameters packet delivery ratio and energy consumption are compared for the CMBCH,DLC and HCAL. The obtained results are compared to others; CMBCH conserves minimal energy and bandwidth and also achieves reliable throughput through stable routing.
Spatial upscaling of CO2 emissions from exposed river sediments of the Elbe River during an extreme drought
Authors: Mallast Ulf , Staniek Maren , Koschorreck Matthias
Published: April 2020

Droughts lead to falling river water levels and consequently expose river sediments. It is well known that from these exposed aquatic sediments, CO2 emits to the atmosphere, but upscaling of CO2 measurements from discrete point measurements to an entire river system remains challenging. Naturally occurring heterogeneous processes must be accounted for to obtain an overall CO2 flux and to assess its significance. We contribute to this challenge by incorporating a two stage scaling approach using in situ CO2 fluxes and remote sensing data. First, by combining optical airborne data with closed chamber measurements at a representative model site during a first scaling stage, we derive land cover type specific CO2 fluxes and identify distance to the water as the most suitable proxy for further upscaling. Second, we upscale derived spatial relations from the first scaling stage to the entire river system of the Elbe River using a satellite‐based analysis. In this way, we derived area‐weighted CO2 emissions from exposed river sediments of 56.6 ± 64.8 tC day−1 (corrected distance proxy) and 52.9 ± 44.6 tC day−1 (land cover proxy), respectively, for 1 day during the 2018 extreme drought. Given the intensification of droughts in terms of length and reoccurrence frequency, this result not only highlights the importance of drought‐induced exposition of river sediment as a source of atmospheric CO2 but also underscores the ability to monitor CO2 emissions over an entire river system on a regular basis using remote sensing.
Pharmacological inhibition of GRK2 improves cardiac metabolism and function in experimental heart failure
Authors: Ciccarelli Michele , Sorriento Daniela , Fiordelisi Antonella , Gambardella Jessica , Franco Antonietta , del Giudice Carmine , Sala Marina , Monti Maria Gaia , Bertamino Alessia , Campiglia Pietro , Oliveti Marco , Poggio Paolo , Trinchese Giovanna , Cavaliere Gina , Cipolletta Ersilia , Mollica Maria Pina , Bonaduce Domenico , Trimarco Bruno , Iaccarino Guido
Published: April 2020

Aims

The effects of GRK2 inhibition on myocardial metabolism in heart failure (HF) are unchartered. In this work, we evaluated the impact of pharmacological inhibition of GRK2 by a cyclic peptide, C7, on metabolic, biochemical, and functional phenotypes in experimental HF.

Methods and results

C7 was initially tested on adult mice ventricular myocyte from wild type and GRK2 myocardial deficient mice (GRK2‐cKO), to assess the selectivity on GRK2 inhibition. Then, chronic infusion of 2 mg/kg/day of C7 was performed in HF mice with cryogenic myocardial infarction. Cardiac function in vivo was assessed by echocardiography and cardiac catheterization. Histological, biochemical, and metabolic studies were performed on heart samples at time points. C7 induces a significant increase of contractility in wild type but not in adult ventricle myocytes from GRK2‐cKO mice, thus confirming C7 selectivity for GRK2. In HF mice, 4 weeks of treatment with C7 improved metabolic features, including mitochondrial organization and function, and restored the biochemical and contractile responses.

Conclusions

GRK2 is a critical molecule in the physiological regulation of cardiac metabolism. Its alterations in the failing heart can be pharmacologically targeted, leading to the correction of metabolic and functional abnormalities observed in HF.
Central role of left atrial dynamics in limiting exercise cardiac output increase and oxygen uptake in heart failure: insights by cardiopulmonary imaging
Authors: Sugimoto Tadafumi , Barletta Marta , Bandera Francesco , Generati Greta , Alfonzetti Eleonora , Rovida Marina , Gnecchi Ruscone Tomaso , Rossi Andrea , Cicoira Mariantonietta , Guazzi Marco
Published: April 2020

Aims

In heart failure (HF), the haemodynamic response to exercise in relation to left atrial (LA) dynamics is unexplored. We sought to define whether abnormal LA dynamics during exercise may play a role in cardiac output (CO) limitation and tested its ability to predict outcome.

Methods and results

A total of 195 HF patients with reduced (n = 105), mid‐range (n = 48), and preserved (n = 42) left ventricular ejection fraction (LVEF) and 46 non‐cardiac dyspnoea (NCD) subjects underwent cardiopulmonary imaging with assessment of LA strain and strain rate (sra). HF patients, irrespective of LVEF, exhibited a significantly impaired LA strain and LA sra at rest, during exercise and recovery compared to NCD subjects with a blunted response in CO and right ventricular to pulmonary circulation coupling. LA strain and LA sra during exertion were significantly correlated with peak stroke volume index, peak CO and peak cardiac power output (R = 0.33, 0.48, 0.50 and R = 0.36, 0.51, 0.52 for LA strain and LA sra, respectively; all P < 0.001). In HF, after adjustment for age, gender, left atrial volume index, peak mitral regurgitation > 2, peak LVEF and peak heart rate, a higher LA strain (1% increase) during exercise was associated with a higher peak stroke volume index (mL/m2), CO (L/min) and cardiac power output (mmHg L/min) at multivariable analyses (β‐coefficients ± standard error = 0.23 ± 0.07, 0.046 ± 0.014 and 0.012 ± 0.004, respectively; P < 0.05). The same associations were found also for LA sra (absolute value) (1/s increase, β‐coefficients ± standard error = 1.91 ± 0.68, 0.43 ± 0.14 and 0.12 ± 0.04, respectively; P < 0.05). Exercise LA strain (adjusted hazard ratio 0.94, 95% confidence interval 0.92–0.97, P < 0.001) and LA sra (adjusted hazard ratio 0.60, 95% confidence interval 0.43–0.84, P = 0.003) were associated with a worse outcome after adjusting for age and gender.

Conclusions

In HF, LA dynamics may play a key role in exercise CO increase due to an impaired forward (left ventricular filling) and backward (right ventricular to pulmonary circulation uncoupling) combination of mechanisms, irrespective of LVEF. The blunted LA strain and LA sra reserve during exercise are associated with a worse cardiopulmonary performance and outcome.
The prevalence and importance of frailty in heart failure with reduced ejection fraction – an analysis of PARADIGM‐HF and ATMOSPHERE
Authors: Dewan Pooja , Jackson Alice , Jhund Pardeep S. , Shen Li , Ferreira João Pedro , Petrie Mark C. , Abraham William T. , Desai Akshay S. , Dickstein Kenneth , Køber Lars , Packer Milton , Rouleau Jean L. , Solomon Scott D. , Swedberg Karl , Zile Michael R. , McMurray John J.V.
Published: April 2020

Aims

Frailty, characterized by loss of homeostatic reserves and increased vulnerability to physiological decompensation, results from an aggregation of insults across multiple organ systems. Frailty can be quantified by counting the number of ‘health deficits’ across a range of domains. We assessed the frequency of, and outcomes related to, frailty in patients with heart failure and reduced ejection fraction (HFrEF).

Methods and results

Using a cumulative deficits approach, we constructed a 42‐item frailty index (FI) and applied it to identify frail patients enrolled in two HFrEF trials (PARADIGM‐HF and ATMOSPHERE). In keeping with previous studies, patients with FI ≤0.210 were classified as non‐frail and those with higher scores were divided into two categories using score increments of 0.100. Clinical outcomes were examined, adjusting for prognostic variables. Among 13 625 participants, mean (± standard deviation) FI was 0.250 (0.10) and 8383 patients (63%) were frail (FI >0.210). The frailest patients were older and had more symptoms and signs of heart failure. Women were frailer than men. All outcomes were worse in the frailest, with high rates of all‐cause death or all‐cause hospitalization: 40.7 (39.1–42.4) vs. 22.1 (21.2–23.0) per 100 person‐years in the non‐frail; adjusted hazard ratio 1.63 (1.53–1.75) (P < 0.001). The rate of all‐cause hospitalizations, taking account of recurrences, was 61.5 (59.8–63.1) vs. 31.2 (30.3–32.2) per 100 person‐years (incidence rate ratio 1.76; 1.62–1.90; P < 0.001).

Conclusion

Frailty is highly prevalent in HFrEF and associated with greater deterioration in quality of life and higher risk of hospitalization and death. Strategies to prevent and treat frailty are needed in HFrEF.
Synthetic Applications of Sulfonium Salts
Authors: Kozhushkov Sergei I. , Alcarazo Manuel
Published: April 2020

This minireview aims to cover the developments over the past two decades in the chemistry of sulfonium salts. Specifically, insight is provided into the synthetic strategies available for the preparation of these compounds, the different reactivity patterns that are expected depending on their structural features or the reaction conditions applied, and the diversity of organic scaffolds that can thereby be synthesized. Additionally, the pros and cons derived from the use of sulfonium salts are presented and critically compared, when possible, in relation to reagents not based on sulfur but depicting similar reactivity.
Highly Efficient and Eco‐Benign Synthesis of 3‐Imidazoheterocyclic‐Substituted Phthalides/Isoindolinones in Water under Catalyst‐ and Additive‐Free Conditions
Authors: Guo Tao , Wang Hui‐Jie , Cao Can‐Can , Chen Kuo‐Hong , Liu Yu , Zhang Pan‐Ke , Zhao Yun‐Hui , Ma Yong‐Cheng
Published: April 2020

A novel catalyst‐ and additive‐free method for synthesis of structurally diverse 3‐imidazoheterocyclic‐substituted phthalides/isoindolinones has been developed in water with good to excellent yields via cyclization reactions of imidazoheterocycles with phthalaldehydic acid and amine. The broad substrate scope, good functional group tolerance, high atom economy, and environmentally benign quality of this method make it an attractive alternative for synthesis of complex biheterocyclic compounds, which are privileged structures in many biologically active compounds.
Oxidation‐etching induced morphology regulation of Cu catalysts for high‐performance electrochemical N2 reduction
Authors: Ji Xuqiang , Wang Ting , Liu Qian , Luo Yongsong , Lu Siyu , Chen Guang , Gao Shuyan , Asiri Abdullah M. , Sun Xuping
Published: April 2020

Renewable‐electricity‐driven N2 reduction is an attractive approach for ambient NH3 synthesis, but active electrocatalysts are needed to enable the N2 reduction reaction. Monolithic electrodes with active components anchored on conductive supports provide many advantages like structural stability, large surface area, and low electrical resistance. Here, a novel “oxidation‐etching” strategy is proposed to carve the surface of Cu foam into structures of particles, cubes, and sheets for N2 reduction electrocatalysis. The optimal catalyst achieves a Faradic efficiency as high as 18% at −0.35 V vs reversible hydrogen electrode (RHE) and a large NH3 yield of 2.45 × 10−10 mol s−1 cm−1 at −0.40 V vs RHE in 0.1 M HCl. Notably, it also shows superior long‐term electrochemical durability, with the preservation of electro‐activity for at least 20 hours.

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Cost‐effective analysis technique for the design of bridges against strike‐slip faulting
Authors: Agalianos Athanasios , Sieber Max , Anastasopoulos Ioannis
Published: April 2020

The paper studies the performance of a typical overpass bridge, with continuous deck and monolithic pier‐deck connections, subjected to strike‐slip faulting. A three‐dimensional (3D) finite element (FE) model of the entire bridge–foundation–abutment–soil system is developed, accounting for soil, structure and geometric nonlinearities. Soil behaviour is simulated with a thoroughly validated strain softening constitutive model. The concrete damaged plasticity (CDP) model is implemented for piers, accounting for the interaction between axial force N, bending moment M, shear force Q and torsion T (NMQT); the model is validated against experimental results from the literature. The location of the fault rupture is parametrically investigated, confirming the vulnerability of indeterminate structural systems to large tectonic deformation. The deck is shown to sustain both in‐plane and out‐of‐plane bending moments, as well as torsion; the piers are subjected to biaxial bending, shear and torsion. The response is highly dependent on the location of the fault rupture, emphasizing the need to develop cost‐effective modelling techniques. Four such techniques are developed (with and without decoupling) and comparatively assessed using the detailed 3D FE model as benchmark. The best prediction is achieved by a coupled model, which includes the bridge superstructure, detailed 3D modelling of the soil‐foundation system only for the pier directly affected by the fault, and nonlinear springs representing the foundations of all other piers. The proposed technique offers a computationally efficient means to parametrically analyse long multispan bridges subjected to faulting, for which full 3D FE modelling is impractical.
Studying smoldering to flaming transition in polyurethane furnituresubassemblies: Effects of fabrics, flame retardants, and material type
Authors: Morgan Alexander B. , Knapp Graham , Stoliarov Stanislav I. , Levchik Sergei V.
Published: April 2020

The transition from smoldering to flaming was studied on fabric, batting, and foam assemblies via an electric spot ignition source of similar intensity to a cigarette. The materials studied included four different fabrics (cotton, polyester, cotton/polyester blend, flame retardant cotton/polyester blend), two types of batting (cotton, polyester), and three types of polyurethane foam (nonflame retardant, flame retardant by FMVSS 302 testing, flame retardant by BS5852 testing). The results from testing found that materials highly prone to smoldering could propagate smoldering into foams and lead to ignition, whereas materials that tended to melt back from the ignition source did not. Flame retardant fabrics or foam can and do prevent the transition from smoldering to flaming provided sufficient levels of flame retardants are incorporated in the upholstery fabric or foam. The transition from smoldering to flaming of cotton fabric/nonflame retardant foam assembly was also studied using temperature measurements and evolved gas analysis. It was determined that the transition takes place when the oxygen consumption by accelerating smoldering front exceeds the oxygen supply. At this point, the solid fuel gasification becomes driven by thermal decomposition rather than by surface oxidation which leads to high enough concentrations of fuel for flaming combustion to occur.
Novel CTNND2‐TERT fusion in a spindle cell liposarcoma
Authors: Occidental Michael , Shen Guomiao , Feng Xiaojun , Zhu Kelsey , Kelly Kevin , Nie Qian , Reddi Honey V. , Lakiotaki Eleftheria , Viniou Nora Athina , Korkolopoulou Penelope , Linos Konstantinos , Jour George
Published: April 2020

Soft tissue tumors can be categorized molecularly into two categories: tumors which are known to have recurrent molecular alterations and tumors which do not have consistent recurrent molecular alterations or translocations. These “nontranslocation” associated sarcomas are clinically more aggressive than their more stable counterparts. However, recent advances in RNA sequencing have discovered recurrent novel fusions within the latter group, namely TERT‐TRIO fusions. Furthermore, a recent report discovered this fusion in a spindle cell liposarcoma. Our case describes a novel fusion of CTNND2, a neighbor gene of TRIO, and TERT in a spindle cell liposarcoma, and provides further evidence that spindle cell liposarcoma should be a distinct entity from dedifferentiated liposarcoma.
Old recipes, new strategies: Paleoenvironment, georesources, building materials, and trade networks in Roman Tuscany (Italy)
Authors: Gliozzo Elisabetta , Fantozzi Pier Lorenzo , Ionescu Corina
Published: April 2020

The Grosseto plain has undergone extensive morphological changes. The shoreline progression has been taking place during the last millennium and has deeply affected settlement, infrastructural, and socioeconomic dynamics. Consequently, this study aims to (a) localize the raw materials exploited during the Roman period for building materials production, (b) reconstruct the production technology, and (c) provide a meaningful reconstruction of the commercial dynamics between local “municipal” productions and “urban” imports. The chemical, mineralogical, and petrographic investigations performed on 34 stamped bricks from the Roman territories of Vetulonia, Rusellae, Heba (Aia Nova), and Saturnia supported the following major achievements: (a) Most of the Rusellan producers used the continental deposits outcropping along the Ombrone River while a few of them exploited the coastal or marine deposits. Aia Nova and Saturnia producers used the Zanclean marine deposits. (b) Brick‐making technology involved very little or no preparation of the paste and firing temperatures ranging between ~650°C and 900°C. Calcite temper was found in Rusellan bricks while decantation was hypothesized for Saturnia bricks only. (c) Commercial dynamics changed abruptly after the the mid 1st century AD when local productions, run by local aristocracies, started declining in favor of urban imports, until being completely supplanted during the Trajan age.
Problems with inattention, reading comprehension, and autonomic regulation on the Stroop task
Authors: Becker Derek R.
Published: April 2020

Direct and moderated connections among symptoms of inattention, High‐Frequency Heart Rate Variability (HF‐HRV), and reading comprehension scores were examined. Children age 7 to 12 were rated by both parents and teachers on symptoms of inattention with the Behavior Assessment System for Children. Reading was assessed with the Peabody Individualized Achievement Test, and HF‐HRV was examined during a Stroop task. Controlling for reading recognition scores, results were consistent with previous work, showing HF‐HRV was significantly negatively associated with reading comprehension, with lower HF‐HRV predicting higher reading scores. HF‐HRV also significantly moderated the relationship between symptoms of inattention and reading comprehension, suggesting that as symptoms of inattention increase, children with low HF‐HRV had higher reading comprehension scores. Variations in parasympathetic reactivity may help explain reading comprehension heterogeneity for children with symptoms of inattention.