bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasmon‐Assisted Broadband All‐Optical Control of Highly Intense Femtosecond Laser by Weak Continuous‐Wave Laser
Authors: Zhang Chi , Wu Hao , Xu Yanming , Xu Jinlong , Yan Zhong , Hu Yonghong , Xie Zhenda , Zhu Shining 
Published: July 2020

AbstractDynamically manipulating highly intense ultrafast pulses by optical modulators is extremely useful for strong‐field physics. However, the manipulation has been severely restricted by the fundamental drawbacks of most modulators such as the low laser damage threshold and high energy consumption. Here, the implementation of an all‐optical modulator on femtosecond lasers up to 1011 W cm−2 covering wavelengths from 1.6 to 2.3 µm is demonstrated; the modulator is controlled by a weak continuous‐wave laser (≈103 W cm−2) based on the prominent plasmon‐assisted thermo‐optic nonlinearity of suspended antimonene quantum dots (AQDs). The strong localization of the surface plasmon of the AQDs contributes a tremendous effective nonlinear refractive index (n2 ≈ 10−5 cm2 W−1) under weak light excitation, modulating the optical phase of copropagating intense lasers, and realizing robust “ON/OFF” alterations. It is also verified that the thermo‐optical effect occurs at a fast speed of ≈240 ps in this nanomaterial system. The findings provide new insight for exploiting the potential of plasmonic nonlinearities of nanomaterials, which offers a pragmatic and extensible solution to the urgent demand for manipulating and optical limiting of strong field physics in further nanophotonic platforms.
Efficient Er/O‐Doped Silicon Light‐Emitting Diodes at Communication Wavelength by Deep Cooling
Authors: Wen Huimin , He Jiajing , Hong Jin , Jin Shenbao , Xu Zhenming , Zhu Hong , Liu Jingquan , Sha Gang , Yue Fangyu , Dan Yaping 
Published: July 2020

AbstractA silicon light source at the communication wavelength is the bottleneck for developing monolithically integrated silicon photonics. Doping silicon with erbium and oxygen ions is considered one of the most promising approaches to produce silicon light sources. However, this method suffers from a high concentration of defects in the form of nonradiative recombination centers at the interface between the crystalline silicon and large Er2O3/ErSi1.7 precipitates during the standard rapid thermal treatment. Here, a deep cooling process is applied to suppress the growth of these precipitates by flushing the high‐temperature Er/O‐doped silicon substrates with helium gas cooled in liquid nitrogen. The resultant light‐emitting efficiency at room temperature is enhanced by two orders of magnitude in comparison with that of the sample treated via standard rapid thermal annealing. The deep‐cooling‐processed Si samples are further processed into light‐emitting diodes. Bright electroluminescence with a main spectral peak at 1536 nm is also observed from the silicon‐based diodes with the external quantum efficiency reaching ≈0.8% at room temperature. Based on these results, the development of electrically driven silicon optical amplifiers or even lasers at communication wavelengths is promising for monolithically integrated silicon photonics.
Silylcarboxylic Acids as Bifunctional Reagents: Application in Palladium‐Catalyzed External‐CO‐Free Carbonylative Cross‐Coupling Reactions
Authors: Li Xiong , Xu Jie , Li Yue , Kramer Søren , Skrydstrup Troels , Lian Zhong 
Published: July 2020

AbstractA palladium‐catalyzed external‐CO‐free carbonylative Hiyama‐Denmark cross‐coupling reaction is presented. The introduction of silylcarboxylic acids as bifunctional reagents (CO and nucleophile source) avoids the need for external gaseous CO and a silylarene coupling partner. The transformation features high functional group tolerance and it is successful with electron‐rich, ‐neutral, and ‐poor aryl iodides. Stoichiometric studies and control experiments provide insight into the reaction mechanism and support the hypothesized dual role of silylcarboxylic acids.magnified image
Enzyme‐catalysed polymer cross‐linking: Biocatalytic tools for chemical biology, materials science and beyond
Authors: Maddock Rosie M. A. , Pollard Gregory J. , Moreau Nicolette G. , Perry Justin J. , Race Paul R. 
Published: July 2020

AbstractIntermolecular cross‐linking is one of the most important techniques that can be used to fundamentally alter the material properties of a polymer. The introduction of covalent bonds between individual polymer chains creates 3D macromolecular assemblies with enhanced mechanical properties and greater chemical or thermal tolerances. In contrast to many chemical cross‐linking reactions, which are the basis of thermoset plastics, enzyme catalysed processes offer a complimentary paradigm for the assembly of cross‐linked polymer networks through their predictability and high levels of control. Additionally, enzyme catalysed reactions offer an inherently ‘greener’ and more biocompatible approach to covalent bond formation, which could include the use of aqueous solvents, ambient temperatures, and heavy metal‐free reagents. Here, we review recent progress in the development of biocatalytic methods for polymer cross‐linking, with a specific focus on the most promising candidate enzyme classes and their underlying catalytic mechanisms. We also provide exemplars of the use of enzyme catalysed cross‐linking reactions in industrially relevant applications, noting the limitations of these approaches and outlining strategies to mitigate reported deficiencies.
Safe, selective histopathological examination of gallbladder specimens: a systematic review
Authors: Bastiaenen V P , Tuijp J E , Dieren S , Besselink M G , Gulik T M , Koens L , Tanis P J , Bemelman W A 
Published: July 2020

AbstractBackgroundRoutine histopathological examination after cholecystectomy is costly, but the prevalence of unsuspected gallbladder cancer (incidental GBC) is low. This study determined whether selective histopathological examination is safe.MethodsA comprehensive search of PubMed, Embase, Web of Science and the Cochrane Library was performed. Pooled incidences of incidental and truly incidental GBC (GBC detected during histopathological examination without preoperative or intraoperative suspicion) were estimated using a random-effects model. The clinical consequences of truly incidental GBC were assessed.ResultsSeventy-three studies (232 155 patients) were included. In low-incidence countries, the pooled incidence was 0·32 (95 per cent c.i. 0·25 to 0·42) per cent for incidental GBC and 0·18 (0·10 to 0·35) per cent for truly incidental GBC. Subgroup analysis of studies in which surgeons systematically examined the gallbladder revealed a pooled incidence of 0·04 (0·01 to 0·14) per cent. In high-incidence countries, corresponding pooled incidences were 0·83 (0·58 to 1·18), 0·44 (0·21 to 0·91) and 0·08 (0·02 to 0·39) per cent respectively. Clinical consequences were reported for 176 (39·3 per cent) of 448 patients with truly incidental GBC. Thirty-three patients (18·8 per cent) underwent secondary surgery. Subgroup analysis showed that at least half of GBC not detected during the surgeon's systematic examination of the gallbladder was early stage (T1a status or below) and of no clinical consequence.ConclusionSelective histopathological examination of the gallbladder after initial macroscopic assessment by the surgeon seems safe and could reduce costs.
Augmented and virtual reality for physics: Experience of Kazakhstan secondary educational institutions
Authors: Daineko Yevgeniya , Ipalakova Madina , Tsoy Dana , Bolatov Zhiger , Baurzhan Zhandos , Yelgondy Yersultanbek 
Published: July 2020

AbstractCurrently, computer‐based training systems, such as virtual laboratories (VLs), are becoming more common not only in universities but also in secondary schools. For physics, VLs are of great importance, as they allow simulating processes that cannot be seen or reproduced. Technologies such as augmented reality (AR) and virtual reality (VR) help us to create such physical visualizations. This study presents a VL, which allows users to solve various physical practical tasks or problems with the help of three‐dimensional process visualizations performed in three different ways, namely desktop VR, AR, and VR using a Leap Motion controller. This study describes in detail the functionality and implementation of a VL. As an experiment, three schools were provided with the necessary equipment and software. Fifty pupils of the 9th grade used the developed VL for half of the academic year, after which they took part in a comprehensive survey. About 88% of them found the laboratory useful for studying physics. The children were satisfied with its functionality and usability. Interviews with teachers helped us to understand which of the three visualization methods is preferable for them and children in the present environment.
Direct Access to the Optimal Regularization Parameter in Distribution of Relaxation Times Analysis
Authors: Schlüter Nicolas , Ernst Sabine , Schröder Uwe 
Published: July 2020

AbstractThe distribution of times (DRT) method has become an important extension for electrochemical impedance investigations. Calculating the DRT is particularly advantageous for complex systems, as it yields an increased resolution in frequency domain. However, the determination of the DRT from experimental impedance data requires special mathematical effort. An often‐used method for the calculation of the DRT is the Tikhonov regularization. The quality of the result of this method depends on the choice of a suitable regularization parameter. This parameter has to be selected by the user. In a former work (N. Schlüter, S. Ernst, U. Schröder, ChemElectroChem 2019, 6, 6027–6037), we showed a method that helps to find the best regularization parameter for given impedance data. However, this test was based on repetitive impedance measurements, which have to be performed at least twice. In this paper, we optimize our previous method to assure the determination of an optimal regularization parameter from just one single impedance spectrum. Eventually, this revision saves measurement time and makes our test also applicable for less time stable measurements.
Transition‐Metal Phosphide/Sulfide Nanocomposites for Effective Electrochemical Non‐Enzymatic Detection of Hydrogen Peroxide
Authors: Wang Caifu , Zhang Zhonghai 
Published: July 2020

AbstractIn this work, we clearly demonstrate the use of a transition‐metal phosphide/sulfide nanocomposite to set up an electrochemical reduction analysis platform for the sensitive and selective non‐enzymatic detection of H2O2. With the help of a macroporous nickel foam (NF) as the substrate, the noble‐metal‐free electrocatalyst nanocomposites of Ni3P and Ni3S2 were directly synthesized in one step on the surface of the NF. The Ni3P‐Ni3S2/NF based electrochemical sensors present excellent electrocatalytic activity for H2O2 reduction with a detection limit of approximately 0.3 μM and a large detection range, which guarantees the possibility of sensitive and reliable detection of H2O2.
Genetic spider monkey‐based routing protocol to increase the lifetime of the network and energy management in WSN
Authors: Soundaram Jothi , Arumugam Chandrasekar 
Published: July 2020

SummaryWireless sensor networks (WSNs) include large distributed nodes in the sensing field. However, the sensor nodes may die due to energy deficiency as they are situated in a hostile environment. Therefore, an energy‐efficient WSN routing protocol is necessary in order to better accommodate the various environmental conditions. In this paper, we have proposed a new Energy‐Efficient Genetic Spider Monkey‐based Routing Protocol (EGSMRP) to improve the stability and lifetime of sensor nodes. The operation of EGSMRP is classified into two stages: (i) setup phase and (ii) steady‐state phase. In the setup phase, GSMO‐based cluster head selection procedure is done. In this phase, the base station utilizes the GSMO algorithm as a device to generate energy‐efficient clusters. Followed with this, the steady‐state phase solves the load balancing issue by utilizing the intracluster data broadcast and dual‐hop intercluster broadcasting algorithm. Thereby, the proposed EGSMRP protocol has shown the energy‐based opportunistic broadcasting with reduced control overhead. Simulation is performed in various conditions to evaluate the effectiveness of the proposed EGSMRP protocol using different metrics such as throughput, control overhead, energy consumption, end‐to‐end delay, and network lifetime. From the simulation results, it was evident that EGSMRP has achieved a higher performance compared to other traditional approaches such as EBAR, MCTRP, IEEMARP, HMCEER, and EFTETRP.
Using primary literature on SARS‐CoV‐2 to promote student learning about evolution
Authors: Hsu Jeremy L. 
Published: July 2020

AbstractThe ongoing COVID‐19 pandemic caused by SARS‐CoV‐2 has caused widespread deaths, illnesses, and societal disruption. I describe here how I pivoted a discussion‐based senior biology capstone course to include a multiweek module surrounding one primary literature paper on the evolution of SARS‐CoV‐2 and the subsequent scientific discourse about the paper. Using a gradual reveal of the paper following the CREATE method (consider, read, elucidate, and think of the next experiment), I challenged students to learn new evolutionary principles and critically analyze the data surrounding the evolution and transmission of SARS‐CoV‐2 presented in the paper. I also provide general advice for implementing this module in future courses.
Thermal biology and growth of bison (Bison bison) along the Great Plains: examining four theories of endotherm body size
Authors: Martin Jeff M. , Barboza Perry S. 
Published: July 2020

AbstractBody size of bison (Bison bison) declines with rising global temperature across the fossil record and rising annual temperatures across the Great Plains, but what are the underlying drivers? Body size depends on growth, which depends on maximizing net energy and nutrient flows for the production of tissues at seasonal scales across the range of the species. We measured thermoregulation costs of body surface temperature (°C) and heat exchanges (W and W/m2) of 350 adult and 345 adolescentBisonfrom 19 herds in summer and winter along the Great Plains from Saskatchewan (52° N) to Texas (30° N). At the smallest scale, daily body surface temperature increased with solar radiation and decreased with relative humidity and wind speed, which is consistent with Kooijman’s dynamic energy budget theory. Total surface heat transfer (W) increased with body mass (kg) at an exponent of 0.63 ± 0.03, which is consistent with Schmidt‐Nielsen’s principle of surface‐area‐to‐volume ratios (b = 0.67). On an annual scale, growth (kg/yr) of adolescentBisondecreased with increasing total surface heat transfer (W) during summer, which supports Speakman and Król’s heat dissipation limit theory. On the largest scale, heat flux was weakly related to latitude in summer and winter for adolescentBison, which provides support for Bergmann’s rule and suggests a role for local primary production along the Great Plains. Cooler summers are more optimal forBisongrowth because of reduced heat loads during the growing season. Rising temperatures are likely to constrain body size and productivity ofBisonand other large endotherms in North America.
A Highly Ordered Hydrophilic–Hydrophobic Janus Bi‐Functional Layer with Ultralow Pt Loading and Fast Gas/Water Transport for Fuel Cells
Authors: Meng Xiantao , Deng Xiang , Zhou Liusheng , Hu Bin , Tan Wenyi , Zhou Wei , Liu Meilin , Shao Zongping 
Published: July 2020

One of the critical challenges that limit broad commercialization of proton exchange membrane fuel cells (PEMFC) is to reduce the usage of Pt while maintaining high power output and sufficient durability. Herein, a novel bi‐functional layer consisting of vertically aligned carbon nanotubes (VACNTs) and nanoparticles of Pt‐Co catalysts (Pt‐Co/VACNTs) is reported for high‐performance PEMFCs. Readily prepared by a two‐step process, the Pt‐Co/VACNTs layer with a hydrophilic catalyst‐loaded side and a hydrophobic gas diffusion side enables a PTFE‐free electrode structure with fully exposed catalyst active sites and superior gas–water diffusion capability. When tested in a PEMFC, the bi‐functional Pt‐Co/VACNTs layer with ultralow Pt loading (~65 μgcathode cm−2) demonstrates a power density of 19.5 kW gPt cathode−1 at 0.6 V, more than seven times that of a cell with commercial Pt/C catalyst (2.7 kW gPt cathode−1 at 0.6 V) at a loading of 400 μgcathode cm−2 tested under similar conditions. This remarkable design of VACNTs‐based catalyst with dual functionalities enables much lower Pt loading, faster mass transport, and higher electrochemical performance and stability. Further, the preparation procedure can be easily scaled up for low‐cost fabrication and commercialization.
Cross‐presentation of dead‐cell‐associated antigens by DNGR‐1+ dendritic cells contributes to chronic allograft rejection in mice
Authors: Balam Saidou , Kesselring Rebecca , Eggenhofer Elke , Blaimer Stephanie , Evert Katja , Evert Matthias , Schlitt Hans J. , Geissler Edward K. , van Blijswijk Janneke , Lee Sonia , Reis e Sousa Caetano , Brunner Stefan M. , Fichtner‐Feigl Stefan 
Published: July 2020

AbstractThe purpose of this study was to elucidate whether DC NK lectin group receptor‐1 (DNGR‐1)‐dependent cross‐presentation of dead‐cell‐associated antigens occurs after transplantation and contributes to CD8+ T cell responses, chronic allograft rejection (CAR), and fibrosis. BALB/c or C57BL/6 hearts were heterotopically transplanted into WT, Clec9a−/−, or Batf3−/− recipient C57BL/6 mice. Allografts were analyzed for cell infiltration, CD8+ T cell activation, fibrogenesis, and CAR using immunohistochemistry, Western blot, qRT2‐PCR, and flow cytometry. Allografts displayed infiltration by recipient DNGR‐1+ DCs, signs of CAR, and fibrosis. Allografts in Clec9a−/− recipients showed reduced CAR (p < 0.0001), fibrosis (P = 0.0137), CD8+ cell infiltration (P < 0.0001), and effector cytokine levels compared to WT recipients. Batf3‐deficiency greatly reduced DNGR‐1+ DC‐infiltration, CAR (P < 0.0001), and fibrosis (P = 0.0382). CD8 cells infiltrating allografts of cytochrome C treated recipients, showed reduced production of CD8 effector cytokines (P < 0.05). Further, alloreactive CD8+ T cell response in indirect pathway IFN‐γ ELISPOT was reduced in Clec9a−/− recipient mice (P = 0.0283). Blockade of DNGR‐1 by antibody, similar to genetic elimination of the receptor, reduced CAR (P = 0.0003), fibrosis (P = 0.0273), infiltration of CD8+ cells (p = 0.0006), and effector cytokine levels. DNGR‐1‐dependent alloantigen cross‐presentation by DNGR‐1+ DCs induces alloreactive CD8+ cells that induce CAR and fibrosis. Antibody against DNGR‐1 can block this process and prevent CAR and fibrosis.
Sensitive CE‐MS method for monitoring of riociguat and desmethylriociguat levels in human serum
Authors: Hložek Tomáš , Štícha Martin , Bursová Miroslava , Jelínek Ivan , Tůma Petr , Čabala Radomír 
Published: July 2020

AbstractRiociguat is novel antihypertensive drug for treatment of pulmonary hypertension. As such, it is still being tested in many clinical and pharmacokinetic trials. Existing methods that determine serum riociguat and desmethylriociguat (DMR) are based solely on liquid chromatography with mass spectrometry. Therefore, we present a novel capillary electrophoresis with mass spectrometry method (CE‐MS) for their determination in human serum as alternative method for ongoing trials. Complete resolution of both analytes was achieved by means of pH optimization of ammonium formate background electrolytes that are fully compatible with ESI/MS detection. Simple liquid‐liquid extraction was used as sample pretreatment. The calibration dependence of the method was linear (in the range of 10–1000 ng/mL), with adequate accuracy (90.1–114.9%) and precision (13.4%). LOD and LOQ were arbitrarily set at 10 ng/mL for both analytes. Clinical applicability was validated using serum samples from patients treated with riociguat in pharmacokinetic study and the results corresponded with reference HPLC‐MS/MS values. Capillary electrophoresis proved to be sensitive and selective tool for the analysis of riociguat and DMR.
Boosting the Performance of Solid Oxide Electrolysis Cells via Incorporation of Gd3+ and Nd3+ Double‐doped Ceria▴
Authors: Park J. H. , Kim K. J. , Jung C. H. , Jeong W. , Shin H. R. , Hong J.‐E. , Lee K. T. 
Published: July 2020

AbstractThe solid oxide electrolysis cell (SOEC) and its developement are in an increasing focus, because of its high efficiency and eco‐friendliness in storing energy by converting electrical energy into hydrogen. Recently, research has been conducted to decrease the operation temperature of SOECs below 750 °C to overcome high system costs and rapid degradation rate at high operation temperatures. Although La0.6Sr0.4Co0.2Fe0.8O3–δ (LSCF) is a promising oxygen electrode for SOEC, when the operating temperature is reduced, the reaction kinetics of the LSCF oxygen electrode is significantly decreased due to high activation energy of the oxygen ion transport. To address this issue, we developed a composite oxygen electrode of LSCF combined with Gd and Nd double doped ceria (GNDC). Due to excellent oxygen ion transport nature of GNDC, the SOEC with the LSCF‐GNDC oxygen electrode yielded impressive current density of ∼1,174 mA cm−2 at 1.3 V at 750 °C along with excellent stability. These results demonstrated that the novel LSCF‐GNDC composite is promising as an efficient and durable oxygen electrode for SOEC applications.
Immunoglobulin profile and B‐cell frequencies are altered with changes in the cellular microenvironment independent of the stimulation conditions
Authors: Moore Dannielle K. , Leisching Gina R. , Snyders Candice I. , Gutschmidt Andrea , van Rensburg Ilana C. , Loxton Andre G. 
Published: July 2020

AbstractIntroductionB‐cells are essential in the defense againstMycobacterium tuberculosis. Studies on isolated cells may not accurately reflect the responses that occur in vivo due to the presence of other cells. This study elucidated the influence of microenvironment complexity on B‐cell polarization and function in the context of tuberculosis disease.MethodsB‐cell function was tested in whole blood, peripheral blood mononuclear cells (PBMCs), and as isolated cells. The different fractions were stimulated and the B‐cell phenotype and immunoglobulin profiles analyzed.ResultsThe immunoglobulin profile and developmental B‐cell frequencies varied for each of the investigated sample types, while in an isolated cellular environment, secretion of immunoglobulin isotypes immunoglobulin A (IgA), IgG2, and IgG3 was hampered. The differences in the immunoglobulin profile highlight the importance of cell‐cell communication for B‐cell activation. Furthermore, a decrease in marginal zone B‐cell frequencies and an increase in T1 B‐cells was observed following cell isolation, indicating impaired B‐cell development in response to in vitro antigenic stimulation in isolation.ConclusionOur results suggest that humoral B‐cell function and development was impaired likely due to a lack of costimulatory signals from other cell types. Thus, B‐cell function should ideally be studied in a PBMC or whole blood fraction.