bluuebunny/crossref_metadata_2025 huggingface dataset:
Culture Substrates for Improved Manufacture of Mesenchymal Stromal Cell Therapies
Authors: Doron Gilad , Temenoff Johnna S.
Published: April 2021

Recent developments in mesenchymal stromal cell (MSC) therapies have increased the demand for tools to improve their manufacture, including the selection of optimal culture substrate materials. While many clinical manufacturers use planar tissue culture plastic (TCP) surfaces for MSC production, others have begun exploring the use of alternative culture substrates that present a variety of spatial, mechanical, and biochemical cues that influence cell expansion and resulting cell quality. In this review, the effects of culture and material properties distinct from traditional planar TCP surfaces on MSC proliferation, surface marker expression, and commonly used indications for therapeutic potency are examined. The different properties summarized include the use of alternative culture formats such as cellular aggregates or 3D scaffolds, as well as the effects of culture substrate stiffness and presentation of specific adhesive ligands and topographical cues. Specific substrate properties can be related to greater cell expansion and improvement in specific therapeutic functionalities, demonstrating the utility of culture materials in further improving the clinical‐scale manufacture of highly secretory MSC products.
Recent Advances of Energy Solutions for Implantable Bioelectronics
Authors: Sheng Hongwei , Zhang Xuetao , Liang Jie , Shao Mingjiao , Xie Erqing , Yu Cunjiang , Lan Wei
Published: April 2021

The emerging field of implantable bioelectronics has attracted widespread attention in modern society because it can improve treatment outcomes, reduce healthcare costs, and lead to an improvement in the quality of life. However, their continuous operation is often limited by conventional bulky and rigid batteries with a limited lifespan, which must be surgically removed after completing their missions and/or replaced after being exhausted. Herein, this paper gives a comprehensive review of recent advances in nonconventional energy solutions for implantable bioelectronics, emphasizing the miniaturized, flexible, biocompatible, and biodegradable power devices. According to their source of energy, the promising alternative energy solutions are sorted into three main categories, including energy storage devices (batteries and supercapacitors), internal energy‐harvesting devices (including biofuel cells, piezoelectric/triboelectric energy harvesters, thermoelectric and biopotential power generators), and external wireless power transmission technologies (including inductive coupling/radiofrequency, ultrasound‐induced, and photovoltaic devices). Their fundamentals, materials strategies, structural design, output performances, animal experiments, and typical biomedical applications are also discussed. It is expected to offer complementary power sources to extend the battery lifetime of bioelectronics while acting as an independent power supply. Thereafter, the existing challenges and perspectives associated with these powering devices are also outlined, with a focus on implantable bioelectronics.
Disorder‐Induced Material‐Insensitive Optical Response in Plasmonic Nanostructures: Vibrant Structural Colors from Noble Metals
Authors: Mao Peng , Liu Changxu , Niu Yubiao , Qin Yuyuan , Song Fengqi , Han Min , Palmer Richard E. , Maier Stefan A. , Zhang Shuang
Published: April 2021

Materials show various responses to incident light, owing to their unique dielectric functions. A well‐known example is the distinct colors displayed by metals, providing probably the simplest method to identify gold, silver, and bronze since ancient times. With the advancement of nanotechnology, optical structures with feature sizes smaller than the optical wavelength have been routinely achieved. In this regime, the optical response is also determined by the geometry of the nanostructures, inspiring flourishing progress in plasmonics, photonic crystals, and metamaterials. Nevertheless, the nature of the materials still plays a decisive role in light–matter interactions, and this material‐dependent optical response is widely accepted as a norm in nanophotonics. Here, a counterintuitive system—plasmonic nanostructures composed of different materials but exhibiting almost identical reflection—is proposed and realized. The geometric disorder embedded in the system overwhelms the contribution of the material properties to the electrodynamics. Both numerical simulations and experimental results provide concrete evidence of the insensitivity of the optical response to different plasmonic materials. The same optical response is preserved with various materials, providing great flexibility of freedom in material selection. As a result, the proposed configuration may shed light on novel applications ranging from Raman spectroscopy, photocatalysis, to nonlinear optics.
Metal‐Free Organoselenium‐Enabled Radical Relay Azidation‐Carbocyclization
Authors: Wang Xin , Guo Sa , Zhang Yan , Zhang Zhiguo , Zhang Guisheng , Ye Yong , Sun Kai
Published: April 2021

An organoselenium‐enabled radical relay Azidation‐carbocyclization reaction for the preparation of azide‐substituted quinoline‐2,4‐diones was developed. A series of previously unknown structurally diverse azide‐ substituted quinoline‐2,4‐diones were obtained under metal‐free and room‐temperature conditions. The key features of this reaction are a broad substrate scope, amenability to gram‐scale synthesis, and easy product derivatization. Preliminary mechanistic studies support participation of an organoselenium species in a radical relay pathway.

magnified image
Photochemical Degradation of Organic Matter in the Atmosphere
Authors: Hu Wei , Liu Dandan , Su Sihui , Ren Lujie , Ren Hong , Wei Lianfang , Yue Siyao , Xie Qiaorong , Zhang Zhimin , Wang Zihan , Yang Ning , Wu Libin , Deng Junjun , Qi Yulin , Fu Pingqing
Published: April 2021

Organic matter in the gas‐phase and particles are important components of the atmosphere. Photochemical degradation is a major transformation pathway of atmospheric organic matter, which changes the atmospherically related life time and the environmental, climatic, and health‐related effects of organic matter, as well as biogeochemical cycles of elements. In addition to field observations and model simulations, laboratory experiments based on smog chambers and flow tubes are important approaches to study the photodegradation mechanisms and influencing factors of atmospheric organics. Isotopic composition is also a useful tracer for photodegradation processes of different organics, for example, carboxylic acids. In this article, research progress on photodegradation of several significant categories of organic pollutants which have aroused widespread concern currently, for example, polycyclic aromatic hydrocarbons, carboxylic acids, brown carbon, organosulfates/organonitrates, microplastics, and bioaerosols, are reviewed. The effects of different degradation mechanisms including photochemical reactions, heterogeneous aqueous reactions, and microbial degradation are also compared. Although the photodegradation of atmospheric organics has been studied to a certain extent, much more effort should be made to fill the large knowledge gap between the actual and simulated photodegradation processes.
Targeting Lymphoid Tissues to Promote Immune Tolerance
Authors: Chen Xiao Yan , Du Guang Sheng , Sun Xun
Published: April 2021

The enormous research progress in autoimmune disorders makes the establishment of long‐term clinical tolerance to autoantigens an accessible goal. This strategy endows lymphoid tissues with the tolerogenic ability to induce an unresponsive state toward autoantigens. Lymphoid tissues, as the crossroads, play integral roles in initiating immune activation and immunoregulation. Enormous efforts have driven the exploration of targeting delivery of tolerogenic agents to lymphoid tissues to reverse autoimmune disorders. Herein, the development of various tolerogenic therapies for autoimmune diseases are reviewed, the mechanisms of action from various lymphoid tissues to appropriate cell types by different administration routes are highlighted, and examples of lymphoid tissue‐targeting strategies to improve tolerogenic therapy potency are discussed. First lymph nodes‐targeting strategies for tolerance induction after interstitial or intra‐lymph node (i.LN) injection are summarized, then liver and spleen‐mediated tolerance after intravenous administration are described, and finally oral tolerance‐based therapies are discussed. It is envisioned that tolerogenic therapy will emerge as a novel treatment for autoimmune diseases.
Efficient Hybrid Amorphous Silicon/Organic Tandem Solar Cells Enabled by Near‐Infrared Absorbing Nonfullerene Acceptors
Authors: Troughton Joel , Neubert Sebastian , Gasparini Nicola , Villalva Diego Rosas , Bertrandie Jules , Seitkhan Akmaral , Paleti Sri Harish Kumar , Sharma Anirudh , De Bastiani Michele , Aydin Erkan , Anthopoulos Thomas D. , De Wolf Stefaan , Schlatmann Rutger , Baran Derya
Published: April 2021

Monolithically stacked tandem solar cells present opportunities to absorb more of the sun's radiation while reducing the degree of energetic loss through thermalization. In these applications, the bandgap of the tandem's constituent subcells must be carefully adjusted so as to avoid competition for photons. Organic photovoltaics based on nonfullerene acceptors (NFAs) have recently exploded in popularity owing to the ease with which their electrical and optical properties can be tuned through chemistry. Here, highly complementary and efficient 2‐terminal tandem solar cells are reported based on a wide bandgap amorphous silicon absorber, and a narrow bandgap NFA bulk‐heterojunction with power conversion efficiencies (PCEs) exceeding 15%. Interface engineering of this tandem device allows for high PCEs across a wide range of light intensities both above and below “1 sun.” Furthermore, the addition of an inorganic silicon subcell enhances the operational stability of the tandem by reducing the light‐stress experienced by the bulk heterojunction, resolving a long‐standing stumbling block in organic photovoltaic research.
Progress in Upscaling Organic Photovoltaic Devices
Authors: Bernardo Gabriel , Lopes Tânia , Lidzey David G. , Mendes Adélio
Published: April 2021

Organic photovoltaic (OPV) cells have recently undergone a rapid increase in power conversion efficiency (PCE) under AM1.5G conditions, as certified by the National Renewable Energy Laboratory (NREL), which have jumped from 11.5% in October 2017 to 18.2% in December 2020. However, the NREL certified PCE of large area OPV modules is still lagging far behind (11.7% in July 2020). Additionally, there has been a rapidly growing interest in the use of OPVs for dim light indoor applications, with reported PCE of some large area (≥1 cm2) devices, under 1000 lux, well above 20%. The transition of OPV from the lab to the market requires the development of effective manufacturing processes that can scale‐up laboratory‐scale devices into large area devices, without sacrificing performance and simultaneously minimizing associated manufacturing costs. This review article focuses on four important challenges that OPV technology has to face to achieve a reliable lab‐to‐fab transfer, namely: i) The upscaling of indium‐tin‐oxide (ITO)‐based single cells and the interconnection of single cells into large area modules; ii) the development of alternatives to vacuum processing; iii) the development of alternatives to ITO‐based substrates; and iv) strategies for improving the lifetime of large area OPV devices.
Toward Better and Smarter Batteries by Combining AI with Multisensory and Self‐Healing Approaches
Authors: Vegge Tejs , Tarascon Jean‐Marie , Edström Kristina
Published: April 2021

With an exponentially growing demand for rechargeable batteries, the development of new ultra‐performant, fully scalable, and sustainable battery technologies and materials must be accelerated. Creating a holistic, closed‐loop infrastructure for materials discovery, manufacturing, and battery testing that utilizes a common data infrastructure and autonomous workflows to bridge big data from all domains of the battery value chain, can pave the way for a transformative reduction in the required time to discovery. By embedding multisensory and self‐healing capabilities in future battery technologies and integrating these with AI and physics‐aware machine learning models capable of predicting the spatio‐temporal evolution of battery materials and interfaces, it will, in time, be possible to identify, predict and prevent potential degradation and failure modes. This will facilitate enhanced battery quality, reliability, and life, for example, by preemptively changing the battery charging conditions or releasing self‐healing additives from the separator membrane, akin to preemptive medicine, and form the basis for inverse design of new battery materials, interfaces, and additives. The large‐scale and long‐term European research initiative BATTERY 2030+ seeks to make this longer‐than ten‐year vision a reality through the development of a versatile and chemistry neutral “Battery Interface Genome—Materials Acceleration Platform” infrastructure (BIG‐MAP).
An Oxygenophilic Atomic Dispersed FeNC Catalyst for Lean‐Oxygen Seawater Batteries
Authors: Meng Rongwei , Zhang Chen , Lu Ziyang , Xie Xiaoying , Liu Yingxin , Tang Quanjun , Li Huan , Kong Debin , Geng Chuan‐Nan , Jiao Yan , Fan Zehui , He Qing , Guo Yong , Ling Guowei , Yang Quan‐Hong
Published: April 2021

A constant energy supply is crucial for the exploration of deep‐sea extreme environments, and a self‐powered energy conversion device is ideal for this situation. Dissolved‐oxygen seawater batteries (SWBs) that generate electricity by reducing the dissolved oxygen are promising candidates but the ultralow oxygen concentration in deep sea limits the reaction kinetics. As a result, oxygenophilic electrocatalysts for lean‐oxygen conditions are urgently needed. A microwave heating method is reported that achieves the ultrafast synthesis of atomic dispersed FeNC catalyst (FeNgraphene (G)/carbon nanotube (CNT)), which possesses high activity and strong oxygenophilic interface between graphene and CNTs. DFT calculations and experimental results both show that the high oxygenophilicity is due to the double‐adsorption sites on the G/CNT interface, and the high activity FeN4 active sites is caused by the charge separation. FeNG/CNT catalysts have an outstanding oxygen reduction reaction (ORR) performance in both O2‐saturated alkaline medium and neutral seawater with half‐wave potentials (E1/2) of 0.929 and 0.704 V, respectively, far better than commercial Pt/C. A SWB shows excellent performance in lean‐oxygen seawater (≈0.4 mg L−1), with a discharge voltage of 1.18 V at 10 mA cm−2. These results suggest a critical role for oxygenophilic catalyst specifically for SWBs under lean‐oxygen conditions.
Gold‐Catalyzed Tandem Cycloisomerization/Ring Expansion of Alkynyl Spiro‐epoxyoxindoles: Access to Furo[2,3‐c]quinolinone Derivatives
Authors: Xiao Jun‐An , Peng Hai , Liang Jin‐Shao , Luo Xiao‐Yan , Cheng Xiu‐Liang , Su Wei
Published: April 2021

A gold‐catalyzed tandem cycloisomerization/ring expansion of alkynyl spiro‐epoxyoxindoles was developed, affording furo[2,3‐c]quinolinones in good to excellent yields with broad substrates scope. This methodology provides an efficient approach to construct furo[2,3‐c]quinolinone moieties. Moreover, the fluorescence properties of furo[2,3‐c]quinolinones are also investigated.
‘I Sometimes Catch Myself Looking Angry or Tired …’: The Impact of Mediating by Zoom
Authors: Golann Dwight
Published: April 2021

To learn how mediating over the Internet is changing mediation, I asked 20 leading mediators from the U.S., Canada, and Britain, who together had conducted more than 1,000 Zoom mediations, what was different about mediating by video. Here is what they told me.
Second‐Order Photonic Topological Corner States in Square Lattices with Low Symmetry
Authors: Kim Kwang‐Hyon
Published: April 2021

In most cases, higher‐order topological insulating phases are observed in crystalline materials and photonic/phononic crystals with high crystalline symmetries. Few exceptions include amorphous and quasi‐crystalline matters, which have recently been demonstrated to exhibit such topological phases as well. This report reveals analytically and numerically that the photonic crystals with asymmetric sublattices can also exhibit second‐order topological insulating phases. The appearance of band inversion for the change of unit cell parameters, the quantized 2D polarizations and topological corner charges, and the generation of corner states explicitly reveal the existence of such second‐order photonic topological insulating phases. Quite interestingly, for arbitrarily shaped asymmetric unit cells, second‐order topological corner states are also observed, provided that the intercell coupling dominates over the intracell one.
Quantitative Nano‐amperometric Measurement of Intravesicular Glutamate Content and its Sub‐Quantal Release by Living Neurons
Authors: Yang Xiao‐Ke , Zhang Fu‐Li , Wu Wen‐Tao , Tang Yun , Yan Jing , Liu Yan‐Ling , Amatore Christian , Huang Wei‐Hua
Published: April 2021

Quantitative measurements of intravesicular glutamate (Glu) and of transient exocytotic release contents directly from individual living neurons are highly desired for understanding the mechanisms (full or sub‐quantal release?) of synaptic transmission and plasticity. However, this could not be achieved so far due to the lack of adequate experimental strategies relying on selective and sensitive Glu nanosensors. Herein, we introduce a novel electrochemical Glu nanobiosensor based on a single SiC nanowire that can selectively measure in real‐time Glu fluxes released via exocytosis by large Glu vesicles (ca. 125 nm diameter) present in single hippocampal axonal varicosities as well as their intravesicular content before exocytosis. These measurements revealed a sub‐quantal release mode in living hippocampal neurons, viz., only ca. one third to one half of intravesicular Glu molecules are released by individual vesicles during exocytotic events. Importantly, this fraction remained practically the same when hippocampal neurons were pretreated with L‐Glu‐precursor L‐glutamine, while it significantly increased after zinc treatment, although in both cases the intravesicular contents were drastically affected.
Synthesis of a Nitrogenase PN‐Cluster Model with [Fe8S7(μ‐Sthiolate)2] Core from the All‐Ferric [Fe4S4(Sthiolate)4] Cubane Synthon
Authors: Moula Golam , Nagasaki Ayaka , Matsumoto Tsuyoshi , Miehlich Matthias E. , Meyer Karsten , Cramer Roger E. , Tatsumi Kazuyuki
Published: April 2021

Constructing synthetic models of the nitrogenase PN‐cluster has been a long‐standing synthetic challenge. Here, we report an optimal nitrogenase PN‐cluster model [{(TbtS)(OEt2)Fe4S3}2(μ‐STbt)2(μ6‐S)] (2) [Tbt=2,4,6‐tris{bis(trimethylsilyl)methyl}phenyl] that is the closest synthetic mimic constructed to date. Of note is that two thiolate ligands and one hexacoordinated sulfide are connecting the two Fe4S3 incomplete cubanes similar to the native PN‐cluster, which has never been achieved. Cluster 2 has been characterized by X‐ray crystallography and relevant physico‐chemical methods. The variable temperature magnetic moments of 2 indicate a singlet ground state (S=0). The Mössbauer spectrum of 2 exhibits two doublets with an intensity ratio of 3:1, which suggests the presence of two types of iron sites. The synthetic pathway of the cluster 2 could indicate the native PN‐cluster maturation process as it has been achieved from the Fe4S4 cubane Fe4S4(STbt)4 (1).
Redox‐Responsive Gene Delivery from Perfluorocarbon Nanoemulsions through Cleavable Poly(2‐oxazoline) Surfactants
Authors: Estabrook Daniel A. , Day Rachael A. , Sletten Ellen M.
Published: April 2021

The clinical utility of emulsions as delivery vehicles is hindered by a dependence on passive release. Stimuli‐responsive emulsions overcome this limitation but rely on external triggers or are composed of nanoparticle‐stabilized droplets that preclude sizes necessary for biomedical applications. Here, we employ cleavable poly(2‐oxazoline) diblock copolymer surfactants to form perfluorocarbon (PFC) nanoemulsions that release cargo upon exposure to glutathione. These surfactants allow for the first example of redox‐responsive nanoemulsions in cellulo. A noncovalent fluorous tagging strategy is leveraged to solubilize a GFP plasmid inside the PFC nanoemulsions, whereupon protein expression is achieved selectively when employing a stimuli‐responsive surfactant. This work contributes a methodology for non‐viral gene delivery and represents a general approach to nanoemulsions that respond to endogenous stimuli.
Redox‐Neutral S‐nitrosation Mediated by a Dicopper Center
Authors: Tao Wenjie , Moore Curtis E. , Zhang Shiyu
Published: April 2021

A redox‐neutral S‐nitrosation of thiol has been achieved at a dicopper(I,I) center. Treatment of dicopper (I,I) complex with excess NO. and thiol generates a dicopper (I,I) di‐S‐nitrosothiol complex [CuICuI(RSNO)2]2+ or dicopper (I,I) mono‐S‐nitrosothiol complex [CuICuI(RSNO)]2+, which readily release RSNO in 88–94 % yield. The S‐nitrosation proceeds by a mixed‐valence [CuIICuIII(μ‐O)(μ‐NO)]2+ species, which deprotonates RS‐H at the basic μ‐O site and nitrosates RS− at the μ‐NO site. The [CuIICuIII(μ‐O)(μ‐NO)]2+ complex is also competent for O‐nitrosation of MeOH. A rare [CuIICuII(μ‐NO)(OMe)]2+ intermediate was isolated and fully characterized, suggesting the S‐nitrosation may proceed through the intermediary of analogous [CuIICuII(μ‐NO)(SR)]2+ species. This redox‐ and proton‐neutral S‐nitrosation process is the first functional model of ceruloplasmin in mediating S‐nitrosation of external thiols, with implications for biological copper sites in the interconversion of NO./RSNO.
A Divergent Strategy for Site‐Selective Radical Disulfuration of Carboxylic Acids with Trisulfide‐1,1‐Dioxides
Authors: Wu Zijun , Pratt Derek A.
Published: April 2021

The direct conversion of carboxylic acids into disulfides is described. The approach employs oxidative photocatalysis for base‐promoted decarboxylation of the substrate, which yields an alkyl radical that reacts with a trisulfide dioxide through homolytic substitution. The trisulfide dioxides are easily prepared by a newly described approach. 1°, 2°, and 3° carboxylic acids with varied substitution are good substrates, including amino acids and substrates with highly activated C−H bonds. Trisulfide dioxides are also used to achieve the γ‐C(sp3)−H disulfuration of amides through a radical relay sequence. In both reactions, the sulfonyl radical that results from substitution propagates the reaction. Factors governing the selectivity of substitution at S2 versus S3 of the trisulfide dioxides have been explored.
Introduction of Photolatent Bases for Locally Controlling Dynamic Exchange Reactions in Thermo‐Activated Vitrimers
Authors: Reisinger David , Kaiser Simon , Rossegger Elisabeth , Alabiso Walter , Rieger Bernhard , Schlögl Sandra
Published: April 2021

Vitrimers exhibit a covalently crosslinked network structure, as is characteristic of classic thermosetting polymers. However, they are capable of rearranging their network topology by thermo‐activated associative exchange reactions when the topology freezing transition temperature (Tv) is exceeded. Despite the vast number of developed vitrimers, there is a serious lack of methods that enable a (spatially) controlled onset of these rearrangement reactions above Tv. Herein, we highlight the localized release of the efficient transesterification catalyst 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD) by the UV‐induced cleavage of a photolatent base within a covalently crosslinked thiol–epoxy network. Demonstrated with stress relaxation measurements conducted well above the network's Tv, only the controlled release of TBD facilitates the immediate onset of transesterification in terms of a viscoelastic flow. Moreover, the spatially resolved UV‐mediated photoactivation of vitrimeric properties is confirmed by permanent shape changes induced locally in the material.
Chemoselective Hydro(Chloro)pentafluorosulfanylation of Diazo Compounds with Pentafluorosulfanyl Chloride
Authors: Shou Jia‐Yi , Xu Xiu‐Hua , Qing Feng‐Ling
Published: April 2021

Pentafluorosulfanyl chloride (SF5Cl) is the most prevalent reagent for the incorporation of SF5 group into organic compounds. However, the preparation of SF5Cl often relies on hazardous reagents and specialized apparatus. Herein, we described a safe and practical synthesis of a bench‐stable and easy‐to‐handle solution of SF5Cl in n‐hexane under gas‐reagent‐free conditions. The synthetic application of SF5Cl was demonstrated through the unprecedented reaction with diazo compounds. The chemoselective hydro‐ and chloropentafluorosulfanylations of α‐diazo carbonyl compounds were developed in the presence of K3PO4 or copper catalyst, respectively. These reactions provide a direct and efficient access to various α‐pentafluorosulfanyl carbonyl compounds of high value for potential applications.
A Unified Approach for the Total Synthesis of cyclo‐Archaeol, iso‐Caldarchaeol, Caldarchaeol, and Mycoketide
Authors: Andringa Ruben L. H. , de Kok Niels A. W. , Driessen Arnold J. M. , Minnaard Adriaan J.
Published: April 2021

Ir‐catalyzed asymmetric alkene hydrogenation is presented as the strategy par excellence to prepare saturated isoprenoids and mycoketides. This highly stereoselective synthesis approach is combined with an established 13C‐NMR method to determine the enantioselectivity of each methyl‐branched stereocenter. It is shown that this analysis is fit for purpose and the combination allows the synthesis of the title compounds with a significant increase in efficiency.
Non‐Planar Perylene Bisimide Analogues with Inserted Carbonyl and Methylene Subunits
Authors: Odajima Mai , Tajima Keita , Fukui Norihito , Shinokubo Hiroshi
Published: April 2021

The synthesis and properties of dinaphthotropone bisimide (DNTrBI) and dinaphthocycloheptatriene bisimide (DNCHepBI) are described. Their molecular design is conceptually based on the insertion of a carbon atom into a perylene bisimide (PBI) core. These molecules adopt non‐planar structures due to the presence of a seven‐membered ring. The PBI derivative into which a carbonyl group was inserted (DNTrBI) immediately underwent nonradiative decay and/or intersystem crossing in its excited state. The PBI derivative into which a methylene group was inserted (DNCHepBI) was susceptible to deprotonation on account of the two electron‐withdrawing naphthalene monoimide units. Subsequent aerobic oxidation resulted in the formation of a C−C bond at the central methylene unit, thus affording a σ‐dimer. The formation of this C−C bond is dynamically redox‐active, i.e., electron injection into the σ‐dimer almost quantitatively regenerated the deprotonated DNCHepBI.
In situ deposition of silver nanoparticles on polydopamine‐coated manganese ferrite nanoparticles: Synthesis, characterization, and application to the degradation of organic dye pollutants as an efficient magnetically recyclable nanocatalyst
Authors: Gürbüz Mustafa Ulvi , Elmacı Gökhan , Ertürk Ali Serol
Published: April 2021

The present paper reports a facile in situ synthesis strategy for the production of MnFe2O4@PDA‐Ag magnetically recyclable core–shell nanospheres by the deposition of silver nanoparticles (AgNPs) to the surface of MnFe2O4@PDA nanocomposites through the reduction of silver ions by the outer polydopamine (PDA) layer. The deposition of AgNPs over MnFe2O4@PDA was validated by scanning electron microscopy–energy‐dispersive X‐ray spectroscopy (SEM‐EDX), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X‐ray diffraction (XRD), and vibrating sample magnetometer (VSM) analysis. The catalytic reduction performance of the obtained MnFe2O4@PDA‐Ag nanospheres were tested over model organic dye pollutants (i.e., methylene blue [MB] and 4‐nitrophenol [4‐NP]) by sodium borohydride. Notably, the as‐prepared MnFe2O4@PDA‐Ag nanocatalyst exhibited significantly enhanced catalytic activity for the reduction of MB (296.52 s−1 g−1) and 4‐NP (92.02 s−1 g−1) compared with the other types of similar Ag‐ and PDA‐based catalytic systems in the recent literature. Moreover, the MnFe2O4@PDA‐Ag nanocatalyst showed excellent recyclability, ease of magnetic separation, and rapid and higher recovery ability with insignificant loss in their catalytic efficiencies even after several cyclic uses. The PDA coating on the surface of MnFe2O4 NPs allocates the surface functionalization for the building of novel catalyst systems. This work presents a simple and practicable for the synthesis of MnFe2O4@PDA‐Ag nanospheres that could have a great potential for the treatment of organic pollutants in wastewater and variety of applications in catalysis.
Guidelines in Practice: Environmental Cleaning
Authors: Link Terri
Published: April 2021

All perioperative personnel are responsible for providing a clean environment for patients undergoing operative or other invasive procedures. A contaminated environment can contribute to the incidence of surgical site infections when a patient’s skin contacts a contaminated surface or personnel touch a contaminated surface and then transmit microbes to the patient. Airborne contaminants may settle on the sterile field or in the surgical wound. The AORN “Guideline for environmental cleaning” provides guidance on cleaning product selection, cleaning procedures, personnel education, competency verification, and monitoring cleanliness through performance improvement processes. This article discusses guideline recommendations for cleaning procedures and cleaning of operating and procedure rooms. A scenario describes how an ambulatory surgery center team identifies gaps in cleaning processes and modifies the cleaning checklist to improve these processes. Perioperative RNs should review the entire guideline for additional information when creating and updating policies and procedures for environmental cleaning.
Green cinnamaldehyde and thymol modified zinc oxide with double synergistic antibacterial effects in polypropylene
Authors: Shi Yanqin , Shen Jiaqi , Yang Dieshuang , Du Junnan , Lu Songyan , Ma Meng , He Huiwen , Chen Si , Wang Xu
Published: April 2021

The green cinnamaldehyde (CA) and thymol (THY) separately or successively modified O‐ZnO (O‐ZnO‐CA, O‐ZnO‐THY, and O‐ZnO‐CA‐THY) were prepared after (3‐aminopropyl) triethoxysilane (KH550) was grafted to the surface of ZnO (O‐ZnO) and characterized by FTIR, TGA, and SEM. Polypropylene composites (PP/O‐ZnO‐CA, PP/O‐ZnO‐THY, and PP/O‐ZnO‐CA‐THY) were prepared by melting the modified O‐ZnO and PP. The antibacterial tests showed that the antibacterial rate of PP/O‐ZnO‐CA and PP/O‐ZnO‐THY against S. aureus and E. coli was obviously enhanced. It indicated an excellent synergetic antibacterial effect of O‐ZnO and the little CA or THY grafted on the surface of O‐ZnO. The antibacterial effect of O‐ZnO‐CA and O‐ZnO‐THY was related to the hydrophobic and hydrophilic groups contained in CA and THY. Importantly, CA and THY in O‐ZnO‐CA‐THY exhibited another excellent synergetic antibacterial effect against both S. aureus and E. coli. The antibacterial rate of three PP composites containing 4 phr O‐ZnO‐CA‐THY against S. aureus and E. coli reached 95% and 90%, respectively. The mechanism was regarded as that CA and THY grafted onto the same O‐ZnO improved the contact probability between antibacterial agents and bacteria. Moreover, O‐ZnO‐CA, O‐ZnO‐THY, and O‐ZnO‐CA‐THY had excellent migration resistance in the PP matrix.
Synthesis of 5H‐indeno[1,2‐b]pyridine derivatives: Antiproliferative and antimetastatic activities against two human prostate cancer cell lines
Authors: Charris Katiuska E. , Rodrigues Juan R. , Ramírez Hegira , Fernandez‐Moreira Esteban , Ángel Jorge E. , Charris Jaime E.
Published: April 2021

This study describes the direct synthesis of 2‐amino‐4‐(phenylsubstituted)‐5H‐indeno[1,2‐b]pyridine‐3‐carbonitrile derivatives 5–21, through sequential multicomponent reaction of aromatic aldehydes, malononitrile, and 1‐indanone in the presence of ammonium acetate and acetic acid (catalytic). The biological study showed that compound 10 significantly impeded proliferation of the cell lines PC‐3, LNCaP, and MatLyLu. The antimetastatic effects of compound 10 could be related with inhibition of MMP9 in the PC‐3 and LNCaP human cell lines. On the basis of a study of the structure–activity relationship of these compounds, we propose that the presence of two methoxy groups at positions 6 and 7 of the indeno nucleus and a 4‐hydroxy‐3‐methoxy phenyl substitution pattern at position 4 of the pyridine ring is decisive for these types of molecules to exert very good antiproliferative and antimetastatic activities.
Understanding the attenuation of the accommodation recommendation spillover effect in view of spatial distance
Authors: Lai Shiyang , Fan Ningyuan
Published: April 2021

This brief communication aims to reveal whether the recommendation information's spillover effect decays with geographical distance. A unique dataset of Airbnb listings in Beijing is collected to perform an empirical analysis and a model simulation. The results of this study demonstrate that the spillover of listings' recommendation information decays with spatial distance and this decay follows a certain attenuation mode (i.e., has a certain attenuation rate and attenuation point). As one of the first to investigate the attenuation mechanism of information spillover, this communication enriches the current research on information transmission and brings a novel topic to the attention of the community.
Perturbed Hill's problem with variable mass
Authors: Bouaziz Ferdaous , Ansari Abdullah A.
Published: April 2021

In the present paper, we investigate the dynamical behavior and motion of an infinitesimal body in the Hill problem under some perturbations. As it has been commonly noticed, this problem can be seen as a particular case of the classical restricted three‐body problem. For numerical investigations, we first set the equations of motion of the infinitesimal body that we suppose having a variable mass according to Jeans' law. We get an effective and perceptible variation due to parameters in both the locations of lagrangian points, regions of motion, and basins of attraction. Finally, we examine the stability for the lagrangian points using Meshcherskii's space–time inverse transformations.
Autophagy in tooth: Physiology, disease and therapeutic implication
Authors: Yang Shengyan , Fan Wenguo , Li Yaoyin , Liu Qing , He Hongwen , Huang Fang
Published: April 2021

Autophagy is an evolutionarily conserved cellular process, in which damaged organelles and proteins are engulfed in autophagic vesicles and subsequently fuse with lysosomes for degradation. Autophagy is widely involved in different physiologic or pathologic processes in human. Accumulating evidence indicates that autophagy operates as a critical quality control mechanism to maintain pulp homeostasis and structural integrity of the dentin‐pulp complex. Autophagy is activated during stresses and is involved in the pathogenesis of pulpitis and periapical infection. Recent discoveries have also provided intriguing insights into the roles of autophagy in tooth development, pulp aging and stress adaptation. In this review, we provide an update on the multifaceted functions of autophagy in physiology and pathophysiology of tooth. We also discuss the therapeutic implications of autophagy modulation in diseases and the regeneration of dentin‐pulp complex.
Functional Nucleic Acids Under Unusual Conditions
Authors: Chang Tianjun , He Sisi , Amini Ryan , Li Yingfu
Published: April 2021

Functional nucleic acids (FNAs), including naturally occurring ribozymes and riboswitches as well as artificially created DNAzymes and aptamers, have been popular molecular toolboxes for diverse applications. Given the high chemical stability of nucleic acids and their ability to fold into diverse sequence‐dependent structures, FNAs are suggested to be highly functional under unusual reaction conditions. This review will examine the progress of research on FNAs under conditions of low pH, high temperature, freezing conditions, and the inclusion of organic solvents and denaturants that are known to disrupt nucleic acid structures. The FNA species to be discussed include ribozymes, riboswitches, G‐quadruplex‐based peroxidase mimicking DNAzymes, RNA‐cleaving DNAzymes, and aptamers. Research within this space has not only revealed the hidden talents of FNAs but has also laid important groundwork for pursuing these intriguing functional macromolecules for unique applications.
Co−Mo−S Nanoflowers Wrapped Oxidized Multi‐Walled Carbon Nanotubes as Efficient Electrocatalysts for Oxygen Evolution Reaction
Authors: Li You , Ji Lifei , Zhou Xian , Li Tiantian , Chen Xijie , Zhang Xin , Yang Fengchun
Published: April 2021

Developing highly active and stable earth‐abundant electrocatalysts for water splitting is of prime importance for renewable energy conversion systems. Herein, we develop a facile hydrothermal process to prepare nanoflowers by compounding Co−Mo−S and oxidized multi‐walled carbon nanotubes (denoted as Co1.5Mo1.0S/o‐MWNTs) as efficient oxygen evolution reaction (OER) catalysts. Oxidized MWNTs could enhance the hydrophilicity and electrical conductivity of the catalyst conductivity. Co and Mo charge transfer can be accelerated after the chemical hybridization of Co, Mo and highly conductive o‐MWNTs. Co is easily oxidized into cobalt oxyhydroxide, which acts as the active site for OER. The electrocatalyst exhibits highly efficient electrocatalytic performances, achieving low overpotential of 311 mV for the OER at current density of 10 mA cm−2 and low Tafel slope of 70 mV dec−1 in alkaline media. The catalyst maintains good stability even after 10 hours of chronoamperometry test at 1.60 V in alkaline solution. This work provides a new direction for boosting the electrocatalytic activity through coupling bimetallic sulfides and constructing with conductive substrate.
Biochemical Characterization and Synthetic Application of α‐1,3‐Glucosyltransferase from Pneumococcus Serotype 18C
Authors: Wang Hong , Sun Chongzhen , Sun Xuan , Zhang Le , Zhao Jielin , Liang Min , Xiao Min , Gu Guofeng
Published: April 2021

The enzymatic activity and function of a new α‐1,3‐glucosyltransferase, Cps18CU, derived from Streptococcus pneumoniae serotype 18C was identified for the first time using the enzymatically synthetic disaccharide Rhaβ1,4‐Glcα‐PP‐O(CH2)11‐OPh as the acceptor substrate. Further investigation on substrate specificity revealed that Cps18CU exhibited broad toleration toward various NDP‐Glc donors and also accepted such disaccharide acceptor containing Rhaβ1,4‐Glc moiety in structure. Finally, Cps18CU was employed into a one‐pot two‐enzyme reaction system, furnishing trisaccharide Glcα1,3‐Rhaβ1,4‐Glcα‐PP‐O(CH2)11‐OPh in an 81 % yield.
Crystal Structures of AlCr2 and MoSi2: Same Structure Type vs. Different Bonding Pattern
Authors: Milosavljević Milica D. , Burkhardt Ulrich , Moll Philip J. W. , König Markus , Borrmann Horst , Grin Yuri
Published: April 2021

In a joint effort utilizing modified sample preparation, microscopy, X‐ray diffraction and micro‐fabrication, it became possible to prepare single crystals of the “hidden” phase AlCr2. High‐resolution X‐ray diffraction analysis is described in detail for two crystals with the similar overall composition, but different degree of disorder, which seems to be the main cause for the differing unit cell parameters. Chemical bonding analysis of AlCr2 in comparison to prototypical MoSi2 shows pronounced differences reflecting the interchange of main group element vs. transition metal as majority component.
Incorporating cytologic adequacy assessment into precision oncology workflow using telepathology: An institutional experience
Authors: Al Zoughbi Wael , Kim David , Alperstein Susan Ann , Ohara Kentaro , Manohar Jyothi , Greco Noah , Khani Francesca , Robinson Brian D. , Rao Rema A. , Elemento Olivier , Mosquera Juan Miguel , Siddiqui Momin T.
Published: April 2021

Background

Tumor sample quality and quantity determine the success of somatic mutation analysis. Thus, a rapid on‐site evaluation (ROSE) tumor cytology adequacy assessment was incorporated into the workflow of precision oncology at Weill Cornell Medicine in New York City. Optimal samples were obtained from 68 patients with metastatic cancer.

Methods

Cytopathologists performed ROSE on fine‐needle aspirate samples via telepathology, and subsequently core‐needle biopsies were obtained. In a retrospective manner, the concordance between adequacy assessment and the success rate of the procedure was evaluated to obtain sufficient tumor tissue for next‐generation sequencing (NGS).

Results

Out of the 68 procedures, 43 were documented as adequate and 25 were documented as inadequate. The diagnostic yield of adequate procedures was 100%. Adequacy evaluation predicted the success rate of molecular profiling in 40 of 43 procedures (93%; 95% CI, 80.9‐98.5 procedures). The success rate of molecular testing was significantly higher in the adequate group: 93% compared with 32% in the inadequate group (P < .0005). Seven procedures that failed to provide quality material for mutational analysis and pathological diagnosis were evaluated as inadequate. Cell block provided sufficient DNA for NGS in 6 cases. In 2 cases, a core biopsy could not be performed; hence, the fine‐needle aspirate material confirmed the diagnosis and was used for NGS testing.

Conclusion

These results support the incorporation of ROSE into the workflow of precision oncology to obtain high‐quality tissue samples from metastatic lesions. In addition, NGS testing of concurrent cytology specimens with adequate cellularity can be a surrogate for NGS testing of biopsy specimens.
Finite Time Blowup for the Nematic Liquid Crystal Flow in Dimension Two
Authors: Lai Chen‐Chih , Lin Fanghua , Wang Changyou , Wei Juncheng , Zhou Yifu
Published: April 2021

We consider the initial boundary value problem of a simplified nematic liquid crystal flow in a bounded, smooth domain Ω ⊂ ℝ2. Given any k distinct points in the domain, we develop a new inner‐outer gluing method to construct solutions that blow up exactly at those k points as t goes to a finite time T. Moreover, we obtain a precise description of the blowup. © 2021 Wiley Periodicals LLC.
Pre‐filtering based summarization for data partitioning in distributed stream processing
Authors: Aslam Adeel , Chen Hanhua , Jin Hai
Published: April 2021

Load balancing among the processing elements (PEs) of distributed stream processing system (DSPS) is a key issue in the presence of data skewness. Existing data partitioning schemes for DSPS suffer from the scalability problem and system in‐efficiency. Non‐key based partitioning strategies raise prohibitively high memory overhead for the stateful operations with a large number of keys and high data parallelism, while the key‐based schemes introduce load imbalance for highly skewed data. Predicting the nature of stream data in advance can help to reduce the load imbalance among the PEs of DSPS. For this purpose, the heavy hitter algorithms approximate the hot items of streaming data. However, existing designs suffer from unsatisfied prediction accuracy. In this work, we propose an efficient algorithm to filter hot items in a stream of incoming data. The proposed scheme dynamically monitors the items of a stream and greatly improves the accuracy of estimation by keeping the actual key‐value pair for the frequent items. On one hand, to ensure better load balancing for the skewed data streams, the detected hot keys are directed to more than two PEs randomly from the limited workers. On the other hand, for less frequent keys, the proposed scheme explores the principle of the power of two choices to distribute load. We conduct extensive experiments on both real‐world and synthetic data sets. The results show that the proposed pre‐filtering approach significantly outperforms existing designs in terms of prediction accuracy. The results also show that our design achieves a more balanced load as compared to the existing designs.
Spatially Resolved Kinetic Model of Parahydrogen Induced Polarisation (PHIP) in a Microfluidic Chip
Authors: Ostrowska Sylwia J , Rana Aabidah , Utz Marcel
Published: April 2021

We report a spatially resolved kinetic finite element model of parahydrogen‐induced polarisation (PHIP) in a microfluidic chip that was calibrated using on‐chip and off‐chip NMR data. NMR spectroscopy has great potential as a read‐out technique for lab‐on‐a‐chip (LoC) devices, but is often limited by sensitivity. By integrating PHIP with a LoC device, a continuous stream of hyperpolarised material can be produced, and mass sensitivities of
have been achieved. However, the yield and polarisation levels have so far been quite low, and can still be optimised. To facilitate this, a kinetic model of the reaction has been developed, and its rate constants have been calibrated using macroscopic kinetic measurements. The kinetic model was then coupled with a finite element model of the microfluidic chip. The model predicts the concentration of species involved in the reaction as a function of flow rate and position in the device. The results are in quantitative agreement with published experimental data.
Co‐infection of Pneumocystis jirovecii pneumonia and pulmonary CMV in a infant with X‐linked severe combined immunodeficiency
Authors: Cheng Lin , Liu Keyu , Luo Xiaojuan , Mao Xiaoning , Chen Yunsheng , Cao Ke
Published: April 2021

We herein report a rare case of co‐infection of Pneumocystis jirovecii pneumonia and pulmonary CMV in a 3‐month‐old infant with X‐linked severe combined immunodeficiency, in which diagnostic clues were obtained from the bronchoalveolar lavage fluid. We focus on the value of cytological diagnosis of P. jirovecii pneumonia and pulmonary CMV in the bronchoalveolar lavage fluid. Recognizing morphological characteristics of these pathogenic microorganisms is important to get timely diagnosis and treatment for the patients. Furthermore, repeated severe infections in infants should remind us to screen for immunosuppressed states.
Three‐phasic pattern of C‐peptide decline in type 1 diabetes patients with partial remission
Authors: Shi Mei , Xie Yuting , Tang Rong , Zhong Ting , Zhou Zhiguang , Li Xia
Published: April 2021

Aims

To explore the different patterns of C‐peptide decline in patients with and without partial remission of newly diagnosed type 1 diabetes (T1D).

Materials and methods

A total of 298 patients with new‐onset T1D were followed up regularly at 3 months' interval to investigate the loss of C‐peptide. Partial remission was determined by postprandial C‐peptide ≥300 pmol/L or insulin dose‐adjusted A1c ≤ 9 in the absence of C‐peptide. Beta‐cell function was defined as preserved, residual or failed by postprandial C‐peptide of ≥200 pmol/L, 50–200 pmol/L or ≤50 pmol/L, respectively.

Results

Altogether, 199 out of 298 patients (125 adults) had partial remission. The pattern of C‐peptide change in patients with partial remission was three‐phasic, demonstrating an upward trend followed by a downward trend of fast first and then slow, while the pattern in patients without partial remission was biphasic, showing an initial fast fall and a subsequent slower decrease. The patterns remained consistent when patients were stratified by the age of onset. At 3 years, there were 71% of the patients with partial remission still had preserved or residual beta‐cell function, while 89% of the patients who had no partial remission developed beta‐cell function failure. In patients whose partial remission ended, the average C‐peptide was still higher than duration‐matched patients without partial remission.

Conclusions

Patients with partial remission of T1D have a distinct three‐phasic pattern of C‐peptide decline, other than the widely recognized biphasic pattern. The effect of partial remission still exist​s after remission ends.