bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasmonic Hot‐Electron‐Induced Control of Emission Intensity and Dynamics of Visible and Infrared Semiconductor Quantum Dots
Authors: Sadeghi Seyed M. , Gutha Rithvik R. , Mao Chuanbin 
Published: April 2020

AbstractPlasmonic hot‐electron‐assisted control of emission intensities and dynamics of CdSe/ZnS and infrared PbS quantum dots are studied. This is done by exploring the impact of Au/Si and Ag/Si Schottky junctions on the decay rates of such quantum dots when these junctions are placed in close vicinity of a Si/Al oxide charge barrier, forming metal‐oxide plasmonic metafilms. Such structures are used to investigate how metal‐dependent distributions of hot electrons and their capture via Schottky junctions can lead to suppression of the defect environments of quantum dots, offering a novel platform wherein off‐resonant (non‐Purcell) plasmonic processes are used to control exciton dynamics. These results show that Ag metafilms can enhance the emission of CdSe/ZnS quantum dots and elongate their lifetimes more than Au metafilms. This highlights the more efficient nature of Ag/Si Schottky junctions for hot electron excitation and capture. These results also show that such junctions can significantly suppress the nonradiative decay rates of PbS quantum dots at frequencies far from the plasmon resonances. These results demonstrate a field‐effect passivation of quantum dot defects via entrapment of hot electrons and control of emission intensities and dynamics of quantum dots via the nearly frequency‐independent electrostatic field of such electrons.
4D Printed Hydrogels: Fabrication, Materials, and Applications
Authors: Dong Yuting , Wang Shancheng , Ke Yujie , Ding Liucheng , Zeng Xianting , Magdassi Shlomo , Long Yi 
Published: April 2020

Abstract4D printed objects are 3D printed structures whose shape, property, and functionality are able to self‐transform when exposed to a predetermined stimulus. The emerging field of 4D printing has attracted wide interest from both academia and industry since first introduced in 2013. Stimuli‐responsive hydrogels have become a competitive and versatile group of materials for 4D printed devices due to their good deformability, promising biocompatibility, simple manufacturing, and low cost. This review aims to provide a summary of the current progress of hydrogel‐based 4D printed objects and devices based on their fabrication techniques, materials, and applications. Herein, presented are: the characteristics of different additive manufacturing methods such as direct ink writing, fused deposition modeling, and stereolithography; the properties of various stimuli‐responsive hydrogels such as poly(N‐isopropylacrylamide) and poly(N,N‐dimethylacrylamide), alginate, etc.; and diverse applications of 4D printed hydrogels such as actuators, cellular scaffolds, and drug release devices. Opportunities and challenges for 4D printed hydrogels are discussed and prospects for future development are elaborated.
Tuning Optical Properties of BODIPY Dyes by Pyrrole Conjugation for Photoacoustic Imaging
Authors: Merkes Jean Michél , Lammers Twan , Kancherla Rajesh , Rueping Magnus , Kiessling Fabian , Banala Srinivas 
Published: April 2020

AbstractPhotoacoustic imaging (PAI) is increasingly employed in (pre‐) clinical research, thus, development of suitable contrast agents, in particular fluorescence‐quenched chromophores, for PAI is of high importance. Small molecule dyes are appropriate due to favorable circulation, excretion properties, and ease of conjugation to targeting moieties. The BODIPY chromophores have been widely used in bioimaging, yet they are not ideal for PAI due to high fluorescence. Hence, here nonfluorescent BODIPY are designed by 1H‐pyrrole conjugation (PyBODIPY) to apply as probes for PAI. The PyBODIPYs exhibit absorption maxima up to 800 nm, and PA signal could be detected in concentrations of 1 nmol mL−1 and 35 pmol mm−3, by tube and tissue phantom, respectively. In addition to nonfluorescent, PyBODIPYs are non‐phototoxic, photostable, and show high molar extinction coefficients, as well as inertness toward nucleophilic addition. PyBODIPYs are modified with PEG‐400, to improve aqueous solubility and to enable in vivo imaging. Thus, PyBODIPY is an attractive small molecule to use as PA contrast agent, which could be coupled to targeting ligands for in vivo use. In addition, 1H‐pyrrole conjugation might be applied to the design of novel near‐infrared ranged quenchers suitable for PAI, and promote the development of probes for clinical translation.
Synthesis of Unnatural α‐Amino Acid Derivatives via Light‐Mediated Radical Decarboxylative Processes
Authors: Merkens Kay , Aguilar Troyano Francisco José , Djossou Jonas , Gómez‐Suárez Adrián 
Published: April 2020

AbstractUnnatural amino acids (UAAs) are key building blocks with widespread application across several scientific fields. Therefore, it is highly attractive to develop straightforward and simple methodologies capable of granting quick access to these species. Herein we report a light‐mediated protocol for the synthesis of UAA via radical decarboxylative processes. This methodology, which employs readily available and abundant starting materials – such as carboxylic and α‐keto acids – proceeds under very mild reaction conditions and shows a high functional group tolerance. In addition, the products of the radical reaction can be readily derivatized to grant rapid access to complex UAAs.magnified image
Bacterial community dissimilarity in soils is driven by long‐term land‐use practices
Authors: Sengupta Aditi , Hariharan Janani , Grewal Parwinder S. , Dick Warren A. 
Published: April 2020

AbstractLand‐use practices impact soil microbial functionality and biodiversity, with reports suggesting that anthropogenic activities potentially result in reduced microbial functions and loss of species. The objective of this study was to assess the effect of long‐term (>50 yr) land use (natural forest and grassland, and agricultural land) on soil bacterial community structure. A high‐throughput sequencing‐by‐synthesis approach of the 16S rRNA gene was used to study bacterial community and predicted functional profiles of Alfisols, as affected by variables including land‐use (forest, grass, agricultural) and soil/crop management (rotation and tillage) in long‐term experimental plots in Hoytville, OH. The distribution of the abundant phyla was different across samples. No‐till soils showed higher diversity indices than the plow‐till (PT) soils. Ordinations across locations suggested that no‐till soils had distinctly different community structure compared with plow‐till soils, while crop rotation within the no‐till plot had highest number of taxa. Overall land use (forest, grass, agronomic treatment) and tillage (within agricultural soils) were found to be significant when evaluating bacterial community dissimilarity. Predictive functional profiles showed that the forest soil had greatest proportion of PICRUSt‐assignable gene functions followed by the no‐till and grassland soils whereas plow‐till soils had the lowest predicted gene abundances across all samples. The results provide a view of soil bacterial diversity and predictive functional capacity in long‐term land‐use and soil/crop management practices, with a potential to inform future experiments to increase our understanding of long‐term impacts of land use on microbial community structure and function.
Introducing the North American project to evaluate soil health measurements
Authors: Norris Charlotte E. , Bean G. Mac , Cappellazzi Shannon B. , Cope Michael , Greub Kelsey L.H. , Liptzin Daniel , Rieke Elizabeth L. , Tracy Paul W. , Morgan Cristine L.S. , Honeycutt C. Wayne 
Published: April 2020

AbstractThe North American Project to Evaluate Soil Health Measurements was initiated with the objective to identify widely applicable soil health measurements for evaluation of agricultural management practices intended to improve soil health. More than 20 indicators were chosen for assessment across 120 long‐term agricultural research sites spanning from north‐central Canada to southern Mexico. The indicators being evaluated include common standard measures of soil, but also newer techniques of visible and near‐infrared reflectance spectroscopy, a smart phone app, and metagenomics. The aim of using consistent sampling and analytical protocols across selected sites was to provide a database of soil health indicator results that can be used to better understand how land use and management has affected the condition of soil ecosystem provisioning for agricultural biomass production and water resources, as well as nutrient and C cycling. The objective of this paper is to provide documentation of the overall design, and methods being employed to identify soil health indicators sensitive across agricultural management practices, pedologies, and geographies.
Corn and sudangrass intercropped with Kura clover for Midwestern pastures
Authors: Nieman Christine C. , Albrecht Kenneth A. , Schaefer Daniel M. 
Published: April 2020

AbstractWarm‐season annual grasses have potential to increase the productivity of Midwestern grazing systems in mid‐summer when cool‐season species production slumps. This research investigated forage nutritive value and steer performance for two warm‐season annual grasses, corn (Zea mays L.) and sudangrass [Sorghum bicolor (L.) Moench.], intercropped with Kura clover (Trifolium abiguum M. Bieb.). Mixtures were rotationally grazed with Holstein (Bos taurus; 242 kg, n = 180 yr−1) steers from 2014 to 2016. Corn–Kura clover (C‐KC) and sudangrass–Kura clover (SG‐KC) were grazed for 24 d from mid‐July to mid‐August and SG‐KC regrowth was grazed an additional 24 d from mid‐Aug to mid‐September. Forage harvested was greater (P < .05) for SG‐KC (3442 ± 223 kg ha−1) than C‐KC (2426 ± 193 kg ha−1). A mixture × year effect (P = .03) was detected for in vitro true digestibility (IVTD) and all forage nutritive variables had year effects (P < .01). Crude protein did not differ between treatments (P = .30), neutral detergent fiber (NDF) was lower (P < .01), and IVTD and NDF digestibility were higher (P < .05) in C‐KC. A mixture × year effect (P < .05) existed because heat stress suppressed average daily gain in the C‐KC grazing session in 2016. Steer gain per hectare was greater for SG‐KC (P < .01), with 318 kg ha−1 and 195 kg ha−1 for SG‐KC and C‐KC, respectively. Despite greater forage nutritive value in C‐KC, SG‐KC resulted in greater animal gain per hectare due to regrowth potential after first grazing.
Learning from amyloid trials in Alzheimer's disease. A virtual patient analysis using a quantitative systems pharmacology approach
Authors: Geerts Hugo , Spiros Athan 
Published: April 2020

AbstractBackgroundMany trials of amyloid‐modulating agents fail to improve cognitive outcome in Alzheimer's disease despite substantial reduction of amyloid β levels.MethodsWe applied a mechanism‐based Quantitative Systems Pharmacology model exploring the pharmacodynamic interactions of apolipoprotein E (APOE), Catechol ‐O ‐methyl Transferase (COMTVal158Met), and 5‐HT transporter (5‐HTTLPR) rs25531 genotypes and aducanumab.ResultsThe model predicts large clinical variability. Anticipated placebo differences on Alzheimer's Disease Assessment Scale (ADAS)‐COG in the aducanumab ENGAGE and EMERGE ranged from 0.77 worsening to 1.56 points improvement, depending on the genotype‐comedication combination. 5‐HTTLPR L/L subjects are found to be the most resilient. Virtual patient simulations suggest improvements over placebo between 4% and 20% at the 10 mg/kg dose, depending on the imbalance of the 5‐HTTLPR genotype and exposure. In the Phase II PRIME trial, maximal anticipated placebo difference at 10 mg/kg ranges from 0.3 worsening to 5.3 points improvement.DiscussionThese virtual patient simulations, once validated against clinical data, could lead to better informed future clinical trial designs.
Predicting a Sharp Decline in Selectivity for Catalytic Esterification of Alcohols from van der Waals Interactions
Authors: Reece Christian , Luneau Mathilde , Friend Cynthia M. , Madix Robert J. 
Published: April 2020

AbstractControlling the selectivity of catalytic reactions is a critical aspect of improving energy efficiency in the chemical industry; thus, predictive models are of key importance. Herein the performance of a heterogeneous, nanoporous Au catalyst is predicted for the complex catalytic self‐coupling of the series of C2–C4 alkyl alcohols, based solely on the known kinetics of the elementary steps of the catalytic cycle for methanol coupling, using scaling methods augmented by density functional theory. Notably, a sharp decrease in selectivity for ester formation with increasing molecular weight to favor the aldehyde due to van der Waals interactions of reaction intermediates with the surface was predicted and subsequently verified quantitatively by experiment. Further, the agreement between theory and experiment clearly demonstrates the efficacy of this approach for building a predictive model of catalytic behavior for a homologous set of reactants using a small set of experimental information.
Judicious Choice of N‐Heterocycles for the Realization of Sky‐Blue‐ to Green‐Emitting Carbazolylgold(III) C^C^N Complexes and Their Applications for Organic Light‐Emitting Devices
Authors: Kwok Wing‐Kei , Tang Man‐Chung , Lai Shiu‐Lun , Cheung Wai‐Lung , Li Lok‐Kwan , Ng Maggie , Chan Mei‐Yee , Yam Vivian Wing‐Wah 
Published: April 2020

AbstractA new class of sky‐blue‐ to green‐emitting carbazolylgold(III) C^C^N complexes containing pyrazole or benzimidazole moieties has been successfully designed and synthesized. Through the judicious choice of the N‐heterocycles in the cyclometalating ligand and the tailor‐made carbazole moieties, maximum photoluminescence quantum yields of 0.52 and 0.39 have been realized in the green‐ and sky‐blue‐emitting complexes, respectively. Solution‐processed and vacuum‐deposited organic light‐emitting devices (OLEDs) based on the benzimidazole‐containing complexes have been prepared. The sky‐blue‐emitting device shows an emission peaking at 484 nm with a narrow full‐width at half‐maximum of 57 nm (2244 cm−1), demonstrating the potential of this class of complexes in the application of OLEDs with high color purity. In addition, high maximum external quantum efficiencies of 12.3 % and a long operational half‐lifetime of over 5300 h at 100 cd m−2 have been achieved in the vacuum‐deposited green‐emitting devices.
The Huisgen Reaction: Milestones of the 1,3‐Dipolar Cycloaddition
Authors: Breugst Martin , Reissig Hans‐Ulrich 
Published: April 2020

AbstractThe concept of 1,3‐dipolar cycloadditions was presented by Rolf Huisgen 60 years ago. Previously unknown reactive intermediates, for example azomethine ylides, were introduced to organic chemistry and the (3+2) cycloadditions of 1,3‐dipoles to multiple‐bond systems (Huisgen reaction) developed into one of the most versatile synthetic methods in heterocyclic chemistry. In this Review, we present the history of this research area, highlight important older reports, and describe the evolution and further development of the concept. The most important mechanistic and synthetic results are discussed. Quantum‐mechanical calculations support the concerted mechanism always favored by R. Huisgen; however, in extreme cases intermediates may be involved. The impact of 1,3‐dipolar cycloadditions on the click chemistry concept of K. B. Sharpless will also be discussed.
Subnanometer Bimetallic Platinum–Zinc Clusters in Zeolites for Propane Dehydrogenation
Authors: Sun Qiming , Wang Ning , Fan Qiyuan , Zeng Lei , Mayoral Alvaro , Miao Shu , Yang Ruoou , Jiang Zheng , Zhou Wei , Zhang Jichao , Zhang Tianjun , Xu Jun , Zhang Peng , Cheng Jun , Yang Dong‐Chun , Jia Ran , Li Lin , Zhang Qinghong , Wang Ye , Terasaki Osamu , Yu Jihong 
Published: April 2020

AbstractPropane dehydrogenation (PDH) has great potential to meet the increasing global demand for propylene, but the widely used Pt‐based catalysts usually suffer from short‐term stability and unsatisfactory propylene selectivity. Herein, we develop a ligand‐protected direct hydrogen reduction method for encapsulating subnanometer bimetallic Pt–Zn clusters inside silicalite‐1 (S‐1) zeolite. The introduction of Zn species significantly improved the stability of the Pt clusters and gave a superhigh propylene selectivity of 99.3 % with a weight hourly space velocity (WHSV) of 3.6–54 h−1 and specific activity of propylene formation of 65.5 mol
gPt−1 h−1 (WHSV=108 h−1) at 550 °C. Moreover, no obvious deactivation was observed over PtZn4@S‐1‐H catalyst even after 13000 min on stream (WHSV=3.6 h−1), affording an extremely low deactivation constant of 0.001 h−1, which is 200 times lower than that of the PtZn4/Al2O3 counterpart under the same conditions. We also show that the introduction of Cs+ ions into the zeolite can improve the regeneration stability of catalysts, and the catalytic activity kept unchanged after four continuous cycles.
Prismarene: An Emerging Naphthol‐Based Macrocyclic Arene
Authors: Yang Liu‐Pan , Jiang Wei 
Published: April 2020

AbstractPhenol‐based macrocyclic arenes have been widely used in supramolecular chemistry, significantly enriching the toolbox of the field. In contrast, naphthol‐based macrocyclic arenes are rather underdeveloped. Very recently, Gaeta and co‐workers successfully synthesized such macrocycles (referred to as prism[n]arenes) with good guest‐binding ability by reacting 2,6‐dimethoxynaphthalene with paraformaldehyde under optimized conditions. In view of the simple synthesis and good host–guest chemistry, we anticipate that this macrocycle will find similar success and wide applications as the phenol‐based macrocyclic arenes.
Urethane acrylate‐based photosensitive resin for three‐dimensional printing of stereolithographic elastomer
Authors: Deng Yuhao , Li Jie , He Zuhan , Hong Jiang , Bao Jianjun 
Published: April 2020

AbstractThree‐dimensional (3D) printing elastomers have received wide attention because of their wide applications in many fields. In this work, we report a urethane acrylate‐based photosensitive resin compound for 3D printing whose cured materials are elastic. This resin consists of bifunctional urethane acrylate (Royji 426 as the main matrix, monofunctional urethane acrylate (Royji 425), and isobornyl methacrylate (IBMA) as the diluents, trimethylolpropane triacrylate (TMPTA) as the crosslinker, phenylbis(2,4,6‐trimethylbenzoyl)‐phosphine oxide (819) and 2‐hydroxy‐2‐methyl propiophenone (1173) as photoinitiators. The results indicate that the mechanical properties of cured materials can be tuned by adjusting the content of different components, but it is also accompanied by the changes in viscosity and volume shrinkage. Real‐time Fourier transform infrared spectroscopy was employed to explore the relationship between the photoinitiators and the rate of initiation, and then found the best photoinitiators formulation. The resultant resin exhibits tensile strength of 7.46 MPa, elongation of 180.6%, viscosity of 978.53 mPa·s at 25°C and the volume shrinkage rate of 4.15%. Some complicated structures can be printed with the photosensitive resin such as C60, hollow ball, wrist strap, and porous lattices. These architectures have excellent dimensional accuracy and can undergo any large deformation without damage. This manifested that this resin can provide a solution for existing 3D printing of elastomers.
Biosimilar Uptake in Academic and Veterans Health Administration Settings: Influence of Institutional Incentives
Authors: Baker Joshua F. , Leonard Charles E. , Lo Re Vincent , Weisman Michael H. , George Michael D. , Kay Jonathan 
Published: April 2020

ObjectiveTo compare uptake in the ordering of biosimilars at a Veterans Affairs Medical Center (VAMC) to that at an academic medical center, where institutional incentives for infused medications differ.MethodsWe performed a cross‐sectional study of medical record data and estimated institutional financial incentives at 2 medical centers in Philadelphia: 1) the University of Pennsylvania Health System (UPHS), and 2) the local VAMC. All ordering events for filgrastim or infliximab products were quantified over time and stratified according to product (biosimilar versus reference product) and center. Financial incentives to the institutions over time were determined based on actual drug costs for the VAMC and average sales prices (ASPs) and Medicare Part B reimbursement rates for UPHS.ResultsThere were 15,761 infusions of infliximab at UPHS, of which 99% were for the reference product. There was a sharper decline in the use of reference products at the VAMC; 62% of the 446 infliximab infusions ordered at the VAMC were for the reference product. ASPs were consistently lower for biosimilar infliximab products, but the estimated institutional financial incentives remained similar over time for biosimilar and reference infliximab at UPHS. At the VAMC, the costs for 100‐mg vials of reference infliximab and infliximab‐abda were $623.48 and $115.58, respectively: a $507.90 (81%) savings per vial.ConclusionThe uptake of infliximab biosimilars has been slow at an academic medical center compared to a nearby VAMC, where financial savings are realized by the institution from its use. Slow adoption of biosimilar medications may impact the rates of decline in costs.
Reliable actuator fault control of positive switched systems with double switchings
Authors: Junfeng Zhang , Li Miao , Raïssi Tarek 
Published: April 2020

AbstractThis paper proposes a novel double switchings reliable control for positive switched systems. Double switchings refer to the switchings of subsystems and faults. Considering the actuator faults during the system operation, a class of periodic switched actuator faults is first considered. A reliable controller is designed using linear copositive Lyapunov functions and an average dwell time switching rule is presented for the systems. Then, two average dwell time switching rules are given for the subsystems and the faults, respectively. A corresponding reliable controller is proposed in terms of linear programming. Compared with existing results, the novel approach contains three advantages: (i) the actuator faults of subsystems are allowed to be varying, (ii) two classes of detailed double switchings rules are designed, and (iii) the presented reliable control framework provides a new methodology to deal with the reliable control problem of general switched systems with faults. Finally, two examples are given to illustrate the validity of the presented results.