bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of supercritical N2, O2, CO2, and NH3 mixtures from the virial equation of state
Authors: Gokul Navneeth , Schultz Andrew J. , Kofke David A.
Published: September 2020

We report virial coefficients up to sixth order in density for N2, O2, NH3, and CO2, covering temperatures from 50 to 1,000 K. The reported values include coefficients and their first three temperature derivatives, for the pure species as well as all of those needed to evaluate full composition dependence of mixtures formed from any or all of these compounds. The values are obtained by calculation of appropriate cluster integrals using Mayer sampling Monte Carlo, with intermolecular interactions described by the Transferable Potential for Phase Equilibria (TraPPE) force field. All coefficients are fit as a function of temperature, yielding a thermodynamic model with analytic dependence on temperature, density, and composition. The coefficients and properties computed from them are compared to experimental data where available.
Demographic and clinical features and subsectoral differences in occupational contact allergens in clothing manufacturing workers
Authors: Tas Betul
Published: September 2020

Background

Epidemiologic data on the occurrence of contact dermatitis (CD) and the contact allergens involved in clothing manufacturing and its subsectors are scarce. This study aimed to determine the extent of occupational contact allergy and differences between work subsectors in clothing employees with CD.

Methods

A cross‐sectional study was conducted with 272 clothing employees, who complained of CD and were diagnosed with occupational allergic contact dermatitis (OACD). Participants worked in accessory, dyeing, sewing, cutting, knitting, packing, cleaning, and ironing subsectors. Data on demographics, working‐subsector, working‐duration, and lesion‐duration were collected, and participants were examined and patch tested.

Results

Participants included 173 females and 99 males. Dyeing workers were most frequently diagnosed with OACD, whereas cutting workers were least. Lesions were mostly located on the hands only. The most frequently detected allergens were nickel sulfate in accessory work; disperse blue‐106 in dyeing, sewing, cutting, and knitting; cobalt chloride in packing; p‐phenylenediamine in cleaning; and budesonide in ironing.

Conclusions

Contact allergens show significant differences in frequency by work subsectors in clothing employees. Careful monitoring of workers for excessive exposures and for early signs of CD is warranted.
Distinct genetic patterns of shared and unique genes across four neurodevelopmental disorders
Authors: Zhang Yijia , Wang Ruochen , Liu Zhenwei , Jiang Shan , Du Lifeng , Qiu Kairui , Li Fengxia , Wang Qiongdan , Jin Jing , Chen Xiaomin , Li Zhongshan , Wu Jinyu , Zhang Na
Published: September 2020

Neurodevelopmental disorders, including autism spectrum disorder (ASD), intellectual disability (ID), developmental disorders (DD) and epileptic encephalopathy (EE), have a strong clinical comorbidity, which indicates a common genetic etiology across various disorders. However, the underlying genetic mechanisms of comorbidity and specificity remain unknown across neurodevelopmental disorders. Based on de novo mutations, we compared systematically the functional characteristics between shared and unique genes under these disorders, as well as the spatiotemporal trajectory of development in brain and common molecular pathways of all shared genes. We observed that shared genes present more constrained against functional rare genetic variation, and harbor more pathogenic rare variants than do unique genes in each disorder. Furthermore, 71 shared genes formed two clusters related to synaptic transmission, transcription regulation and chromatin regulator. Particularly, we also found that two core genes STXBP1 and SCN2A, that were shared by the four neurodevelopmental disorders showed prominent pleiotropy. Our findings shed light on the shared and specific patterns across neurodevelopmental disorders and will enable us to further comprehend the etiology and provide valuable information for the diagnosis of neurodevelopmental disorders.
Bamford‐Stevens and Shapiro Reactions in Organic Synthesis
Authors: Ghavre Mukund
Published: September 2020

Total synthesis of natural products often requires installation of double bond without adding carbon. Bamford‐Stevens and Shapiro reactions offer an option to execute such transformation. Several developments have been made in these reactions and their applications in a diverse area of chemistry. Lack of a dedicated review on these reactions in the recent time is hampering an access to collective information and a critical analysis of the new developments. This minireview highlights methodological developments and applications of Bamford‐Stevens and Shapiro reactions in organic synthesis published in the past ten years.
Metal‐Free Decarboxylation of Alkynoic Acids for the Synthesis of Terminal Alkynes
Authors: Seo Eunkyeong , Oh Jonghoon , Lee Sunwoo
Published: September 2020

Terminal alkynes were readily obtained via the reaction of alkynoic acids with N,N,N’,N’‐teramethylethylenediamine (TMEDA) in DMSO at 65 °C for 12 h. This method gave good yields and showed high functional group tolerance. In addition, deuterated terminal alkynes were formed in good yields when alkynoic acids were treated with D2O prior to the reaction with TMEDA.
Electrochemical Oxidation‐induced Difunctionalization of Alkynes and Alkenes with Sulfonyl Hydrazides: Facile Access to β‐Selenovinyl Sulfones and β‐Ketosulfones
Authors: Kong Xianqiang , Yu Ke , Chen Qianjin , Xu Bo
Published: September 2020

We report here in an efficient electrochemical oxidative selenosulfonylation of alkynes and oxysulfonylation of alkenes without use of metal catalysts. This method provides a practical access to a wide range of β‐(seleno)vinyl sulfones and β‐keto sulfones. These reactions can tolerate various functional groups and be easily scaled‐up.
RuCl3 Catalyzed Reaction of Chromones with Bestmann‐Ohira Reagent for the Construction of 2‐Hydroxybenzoyl‐1H‐pyrazolylphosphonates and Dihydrochromeno[3,2‐c]pyrazolylphosphonates
Authors: Kommera Rajkumar , Balasubramanian Sridhar , Raju Bhimapaka China
Published: September 2020

A novel and efficient method has been developed for the synthesis of 2‐hydroxybenzoyl‐1H‐pyrazolylphosphonates and dihydrochromeno[3,2‐c]pyrazolylphosphonates by the reaction of 3‐formylchromones/3‐halo‐4H‐chromenones with Bestmann‐Ohira Reagent (BOR) in the presence of RuCl3 catalyst. The reactions proceeded through decarbonylation, debromination, intramolecular cyclization and N‐methylation to provide the new heterocyclic compounds in one‐pot with the formation of C−C and C−N bonds. The structure assignment of compound 3 f was confirmed by X‐ray analysis.
Intermolecular C‐Arylation of 2‐Amidobiphenyls Overcoming Intramolecular N‐Arylation
Authors: Bal Ankita , Maiti Saikat , Mal Prasenjit
Published: September 2020

2‐Amidobiphenyls are known to undergo intramolecular N−H arylation in presence of hypervalent iodine(III) reagents which lead to C−N coupling reaction. Herein, an unprecedented intermolecular C−C coupling reaction via carbenium ion over a nitrenium ion has been reported using sole oxidant PhI(OAc)2 suppressing the more facile intramolecular C−N coupling.
Systematic review of anterior congenital cephaloceles: open vs endoscopic repair
Authors: Thompson Harrison M. , Cho Do‐Yeon , Riley Kristen O. , Grayson Jessica W. , Woodworth Bradford A.
Published: September 2020

Background

Anterior cephaloceles are rare congenital malformations that have historically been corrected via open approaches. Although the advent of endoscopic endonasal surgery has provided a minimally invasive and theoretically less morbid approach to the anterior skull base, whether endoscopic approaches provide superior treatment outcomes to open techniques has yet to be elucidated. The objective of this study was to systematically review the available literature regarding presentation and outcomes of open vs endoscopic repair of congenital anterior cephaloceles.

Methods

A systematic review of the PubMed, Embase, CINAHL, and Cochrane databases was performed on January 15, 2020, to identify studies from the past 50 years reporting cases of congenital anterior cephaloceles. Data on gender, age at operation, imaging modality, cephalocele location, operative approach, and intra‐ and postoperative complications were collected.

Results

Nonduplicated data (153 articles) consisted of 781 patients with congenital anterior encephaloceles. Surgical outcomes were reported in 349 patients (222 open approaches, 127 endoscopic approaches), with an average age of 4.6 years. There was a 1.3:1 male‐to‐female ratio. Clinical presentation included nasal obstruction (n = 154), hypertelorism (n = 106), and cleft lip/palate (n = 100). Defects were classified as sincipital (n = 479) or basal (n = 257), with 45 patients broadly classified as anterior. The number of complications experienced per operation was 0.13 for endoscopic and 0.44 for open approaches (p < 0.0001). Mortality was significantly lower for the endoscopic group compared with patients treated with open surgery (0.008 vs 0.05, p < 0.05).

Conclusion

Endoscopic repair of congenital anterior cephaloceles resulted in decreased postoperative complications and mortality compared with open approaches. ©2020 ARSAAOA, LLC.
Epidemiology of early onset dementia and its clinical presentations in the province of Modena, Italy
Authors: Chiari Annalisa , Vinceti Giulia , Adani Giorgia , Tondelli Manuela , Galli Chiara , Fiondella Luigi , Costa Manuela , Molinari Maria A. , Filippini Tommaso , Zamboni Giovanna , Vinceti Marco
Published: September 2020

Introduction

Patients with early onset dementia (EOD), defined as dementia with symptom onset at age <65, frequently present with atypical syndromes. However, the epidemiology of different EOD presentations, including variants of Alzheimer's disease (AD) and frontotemporal dementia (FTD), has never been investigated all together in a population‐based study. Epidemiologic data of all‐cause EOD are also scarce.

Methods

We investigated EOD epidemiology by identifying patients with EOD seen in the extended network of dementia services of the Modena province, Northern Italy (≈700,000 inhabitants) from 2006 to 2019.

Results

In the population age 30 to 64, incidence was 13.2 per 100,000/year, based on 160 new cases from January 2016 to June 2019, and prevalence 74.3 per 100,000 on June 30, 2019. The most frequent phenotypes were the amnestic variant of AD and behavioral variant of FTD.

Discussion

EOD affects a significant number of people. Amnestic AD is the most frequent clinical presentation in this understudied segment of the dementia population.
Circulating Lipoprotein Lipids, Apolipoproteins and Ischemic Stroke
Authors: Yuan Shuai , Tang Bowen , Zheng Jie , Larsson Susanna C.
Published: September 2020

Objective

We conducted a Mendelian randomization (MR) study to disentangle the comparative effects of lipids and apolipoproteins on ischemic stroke.

Methods

Single‐nucleotide polymorphisms associated with low‐ and high‐density lipoprotein (LDL and HDL) cholesterol, triglycerides, and apolipoprotein A‐I and B (apoA‐I and apoB) at the level of genomewide significance (p < 5 × 10−8) in the UK Biobank were used as instrumental variables. Summary‐level data for ischemic stroke and its subtypes were obtained from the MEGASTROKE consortium with 514,791 individuals (60,341 ischemic stroke cases, and 454,450 non‐cases).

Results

Increased levels of apoB, LDL cholesterol, and triglycerides were associated with higher risk of any ischemic stroke, large artery stroke, and small vessel stroke in the main and sensitivity univariable MR analyses. In multivariable MR analysis including apoB, LDL cholesterol, and triglycerides in the same model, apoB retained a robust effect (p < 0.05), whereas the estimate for LDL cholesterol was reversed, and that for triglycerides largely attenuated. Decreased levels of apoA‐I and HDL cholesterol were robustly associated with increased risk of any ischemic stroke, large artery stroke, and small vessel stroke in all univariable MR analyses, but the association for apoA‐I was attenuated to the null after mutual adjustment.

Interpretation

The present MR study reveals that apoB is the predominant trait that accounts for the etiological basis of apoB, LDL cholesterol, and triglycerides in relation to ischemic stroke, in particular large artery and small vessel stroke. Whether HDL cholesterol exerts a protective effect on ischemic stroke independent of apoA‐I needs further investigation. ANN NEUROL 2020;88:1229–1236
Small‐Volume Plasmonic Microwell Array with 3D Hierarchical Nanomaterials for Plasmon‐Enhanced Fluorescence Immunoassay
Authors: Choi Wook , Lee Won-Chul , Mun ChaeWon , Kim Sunho , Ansah Iris Baffour , Kim Shin-Hyun , Kim Dong-Ho , Jung Ho Sang , Park Sung-Gyu
Published: September 2020

Developing a small‐volume bioassay using microliter‐scale biofluids is crucial for achieving a rapid, sensitive, and high‐throughput screening and medical diagnosis. Herein, a new plasmonic microwell array (PMA) containing 3D hierarchical nanomaterials for multiplexed bioassays is presented. The microwell array is formed by performing a sequential bottom‐up fabrication involving dispensing UV‐curable photopolymers and plasmonic Ag nanowires (NWs) on a flat substrate. The plasmonic Ag NWs are developed into a multilayer stack of Ag@Au core‐shell NWs having surfaces densely decorated with Au nanoparticles. This multi‐stacked hybrid plasmonic nanostructure provided 3D multiscale hotspots and large effective surfaces for molecular binding sites. Highly improved sensitivities are demonstrated for a plasmon‐enhanced fluorescence‐based immunoassay of cardiac troponin I (cTnI), a diagnostic biomarker for acute myocardial infarction, using a small volume of 5 μL. The limit of detection is determined to be 2.02 pg mL−1 for cTnI, representing a 30‐fold greater sensitivity than the clinical cut‐off value. Furthermore, 3D PMA chips exhibit a highly uniform fluorescence intensity with a coefficient of variation of 3.4%. The 3D PMA provides a sensitive and reliable detection in a high‐throughput manner for point‐of‐care bioanalysis.
Reflection and Refraction of an Airy Pulse at a Moving Temporal Boundary
Authors: Cai Wangyang , Tian Yingying , Zhang Lifu , He Hairong , Zhao Jiajia , Wang Jin
Published: September 2020

Reflection and refraction of Airy pulses at a moving step refractive‐index boundary are investigated. A comb‐like reflected spectrum and an Airy‐like transmitted spectrum are formed as an Airy pulse crosses a temporal boundary without initial group velocity mismatch or initial central frequency shift. The reflected and refracted pulses are significantly influenced by the location of temporal boundary and time‐dependent refractive index change. The energy of each lobe of the comb‐like reflected spectra can be controlled by changing the value of decay factor of the Airy pulse. In the case of an Airy pulse with an initial launch frequency shift, the reflected and refracted frequency shifts depend on the dispersion relation of the medium. The results can be used in potential applications involving optical manipulation.
Conjugated Nanohoops Incorporating Donor, Acceptor, Hetero‐ or Polycyclic Aromatics
Authors: Hermann Mathias , Wassy Daniel , Esser Birgit
Published: September 2020

In the last 13 years several synthetic strategies were developed that provide access to [n]cycloparaphenylenes ([n]CPPs) and related conjugated nanohoops. A number of potential applications emerged, including optoelectronic devices, and their use as templates for carbon nanomaterials and in supramolecular chemistry. To tune the structural or optoelectronic properties of carbon nanohoops beyond the size‐dependent effect known for [n]CPPs, a variety of aromatic rings other than benzene were introduced. In this Review, we provide an overview of the syntheses, properties, and applications of conjugated nanohoops beyond [n]CPPs with intrinsic donor/acceptor structure or such that contain acceptor, donor, heteroaromatic or polycyclic aromatic units within the hoop as well as conjugated nanobelts.
Interfacial Structure of Water as a New Descriptor of the Hydrogen Evolution Reaction
Authors: Shen Lin‐fan , Lu Bang‐an , Li Yu‐yang , Liu Jia , Huang‐fu Zhi‐chao , Peng Hao , Ye Jin‐yu , Qu Xi‐ming , Zhang Jun‐ming , Li Guang , Cai Wen‐bin , Jiang Yan‐xia , Sun Shi‐gang
Published: September 2020

Driven by the persisting poor understanding of the sluggish kinetics of the hydrogen evolution reaction (HER) on Pt in alkaline media, a direct correlation of the interfacial water structure and activity is still yet to be established. Herein, using Pt and Pt–Ni nanoparticles we first demonstrate a strong dependence of the proton donor structure on the HER activity and pH. The structure of the first layer changes from the proton acceptors to the donors with increasing pH. In the base, the reactivity of the interfacial water varied its structure, and the activation energies of water dissociation increased in the sequence: the dangling O−H bonds < the trihedrally coordinated water < the tetrahedrally coordinated water. Moreover, optimizing the adsorption of H and OH intermediates can re‐orientate the interfacial water molecules with their H atoms pointing towards the electrode surface, thereby enhancing the kinetics of HER. Our results clarified the dynamic role of the water structure at the electrode–electrolyte interface during HER and the design of highly efficient HER catalysts.
Tumor Microenvironment Stimuli‐Responsive Fluorescence Imaging and Synergistic Cancer Therapy by Carbon‐Dot–Cu2+ Nanoassemblies
Authors: Sun Shan , Chen Qiao , Tang Zhongdi , Liu Chuang , Li Zhongjun , Wu Aiguo , Lin Hengwei
Published: September 2020

A method is developed to fabricate tumor microenvironment (TME) stimuli‐responsive nanoplatform for fluorescence (FL) imaging and synergistic cancer therapy via assembling photosensitizer (chlorine e6, Ce6) modified carbon dots (CDs‐Ce6) and Cu2+. The as‐obtained nanoassemblies (named Cu/CC nanoparticles, NPs) exhibit quenched FL and photosensitization due to the aggregation of CDs‐Ce6. Their FL imaging and photodynamic therapy (PDT) functions are recovered efficiently once they entering tumor sites by the stimulation of TME. Introducing of Cu2+ not only provides extra chemodynamic therapy (CDT) function through reaction with hydrogen peroxide (H2O2), but also depletes GSH in tumors by a redox reaction, thus amplifying the intracellular oxidative stress and enhancing the efficacy of reactive oxygen species (ROS) based therapy. Cu/CC NPs can act as a FL imaging guided trimodal synergistic cancer treatment agent by photothermal therapy (PTT), PDT, and thermally amplified CDT.
Design and Synthesis of TY‐Phos and Application in Palladium‐Catalyzed Enantioselective Fluoroarylation ofgem‐Difluoroalkenes
Authors: Lin Tao‐Yan , Pan Zhangjin , Tu Youshao , Zhu Shuai , Wu Hai‐Hong , Liu Yu , Li Zhiming , Zhang Junliang
Published: September 2020

The first example of highly enantioselective fluoroarylation of gem‐difluoroalkenes with aryl halides is presented by using a new chiral sulfinamide phosphine (Sadphos) type ligandTY‐Phos. N‐Me‐TY‐Phoscan be easily synthesized on a gram scale from readily available starting materials in three steps. Salient features of this work including readily available starting materials, good yields, high enantioselectivities as well as broad substrate scope make this approach very practical and attractive. Notably, the asymmetric synthesis of an analogue of a biologically active molecule is also reported.
Multiplex‐Nachweis von Analyten auf einem einzelnen Teststreifen mit Antikörper‐gesteuerten und Indikator freisetzenden mesoporösen Nanopartikeln
Authors: Climent Estela , Biyikal Mustafa , Gröninger Delia , Weller Michael G. , Martínez‐Máñez Ramón , Rurack Knut
Published: September 2020

Vor dem Hintergrund der einzigartigen Modularität, hohen Empfindlichkeit und Selektivität von Antikörper‐gesteuerten Indikatorfreisetzungssystemen (gAID‐Systemen) wurde hier ein Multiplex‐Assay für drei organische Explosivstoffmoleküle (TATP, TNT, PETN) entwickelt, der es erlaubt, die Analyten gleichzeitig in flüssiger Phase mit einem einzelnen Teststreifen und einem Fluoreszenzlesegerät bzw. Smartphone als Detektor in Konzentrationen bis in den unteren ppb‐Bereich in <5 min nachzuweisen. Alle drei Systeme, darunter die hier neu entwickelten Systeme für TNT und PETN, tolerieren zudem nicht nur gepufferte wässrige Modelllösungen, sondern auch komplexere Matrices. Neben einem konventionellen Teststreifen mit einem Kanal erlaubte uns die Anwendung von Wachsdrucktechnologie das Herstellen von mehrkanaligen Streifen mit vergleichbarer analytischer Leistungsfähigkeit, was das enorme Potenzial der modular aufgebauten, hybriden Biosensormaterialien im Hinblick auf eine für den Endanwender maßgeschneiderte Vor‐Ort‐Analytik unterstreicht.
Expedient Synthetic Identification of a P‐Stereogenic Ligand Motif for the Palladium‐Catalyzed Preparation of Isotactic Polar Polypropylenes
Authors: Seidel Falk William , Tomizawa Izumi , Nozaki Kyoko
Published: September 2020

The iso‐specific statistical copolymerization of unprotected polar monomers with propylene remains a grand challenge in the field of polymer chemistry. Current research is hampered because only a single natural‐product‐derived dimenthylphosphine‐motif is known to allow for the preparation of moderately isotactic polypropylene copolymers. To overcome this structural limitation, we developed time‐efficient synthetic methods that facilitate P‐donor ligand development. The strength of these methods was demonstrated with preparation of twenty‐five new P‐stereogenic phosphine/sulfonate‐ and bisphosphine‐monoxide‐type palladium catalysts, which could typically be developed in parallel. A lead candidate was identified for iso‐specific propylene polymerization. The best‐performing catalysts utilizing the P‐stereogenic donor motif achieved triad isotacticities of up to mm=0.75—the highest value within those reported for group 10 metal catalysts—for the homo‐ and copolymerization of propylene with unprotected polar monomers at an industrially relevant temperature of 50 °C.
Supramolecular Catalysis of the oxa‐Pictet–Spengler Reaction with an Endohedrally Functionalized Self‐Assembled Cage Complex
Authors: Ngai Courtney , Sanchez‐Marsetti Colomba M. , Harman W. Hill , Hooley Richard J.
Published: September 2020

An endohedrally functionalized self‐assembled Fe4L6 cage complex can catalyze oxa‐Pictet—Spengler cyclizations of tryptophols and various aldehyde derivatives, showing strong rate accelerations and size‐selectivity. Selective molecular recognition of substrates controls the reactivity, and the cage is capable of binding and activating multiple different species along the multistep reaction pathway. The combination of a functionalized active site, size‐selective reactivity, and multistep activation, all from a single host molecule, illustrates the biomimetic nature of the catalysis.
Turning on Zn 4s Electrons in a N2‐Zn‐B2 Configuration to Stimulate Remarkable ORR Performance
Authors: Wang Jing , Li Hongguan , Liu Shuhu , Hu Yongfeng , Zhang Jing , Xia Meirong , Hou Yanglong , Tse John , Zhang Jiujun , Zhao Yufeng
Published: September 2020

A zinc‐based single‐atom catalyst has been recently explored with distinguished stability, of which the fully occupied Zn2+ 3d10 electronic configuration is Fenton‐reaction‐inactive, but the catalytic activity is thus inferior. Herein, we report an approach to manipulate the s‐band by constructing a B,N co‐coordinated Zn‐B/N‐C catalyst. We confirm both experimentally and theoretically that the unique N2‐Zn‐B2 configuration is crucial, in which Zn+(3d104s1) can hold enough delocalized electrons to generate suitable binding strength for key reaction intermediates and promote the charge transfer between catalytic surface and ORR reactants. This exclusive effect is not found in the other transition‐metal counterparts such as M‐B/N‐C (M=Mn, Fe, Co, Ni and Cu). Consequently, the as‐obtained catalyst demonstrates impressive ORR activity, along with remarkable long‐term stability in both alkaline and acid media. This work presents a new concept in the further design of electrocatalyst.
Construction of Cationic Azahelicenes: Regioselective Three‐Component Annulation Using In Situ Activation Strategy
Authors: Wang Zhishuo , Jiang Linfeng , Ji Jinwen , Zhou Fulin , Lan Jingbo , You Jingsong
Published: September 2020

Described herein is a strategy to construct cationic azahelicenes through the three‐component annulation reaction of isoquinoline, indole, and 1,2‐dichloroethane (DCE), in which DCE serves as an in situ activating agent for C1−H activation of isoquinoline, a vinyl equivalent, and a solvent. This in situ activation annulation reaction features a facile one‐step synthesis and complete regioselectivity. The complete regioselectivity of C1 over C3 for the isoquinoline ring paves a path to the helical structure in a highly ordered sequence. One of the synthesized ionic [5]azahelicenium fluorophores exhibits the potential to serve as a mitochondria‐targeted biomarker with good photostability and low cytotoxicity.
Stimuli‐Responsive Luminescent Properties of Tetraphenylethene‐Based Strontium and Cobalt Metal–Organic Frameworks
Authors: Guo Xiaolei , Zhu Nansong , Wang Shi‐Ping , Li Guanghua , Bai Fu‐Quan , Li Yi , Han Yonghao , Zou Bo , Chen Xiao‐Bo , Shi Zhan , Feng Shouhua
Published: September 2020

Herein we report two new TPE‐based 3D MOFs, that is, Sr‐ETTB and Co‐ETTB (TPE=Tetraphenylethylene, H8ETTB=4′,4′′′,4′′′′′,4′′′′′′′‐(ethene‐1,1,2,2‐tetrayl)tetrakis(([1,1′‐biphenyl]‐3,5‐dicarboxylic acid))). Through tailoring outer shell electron configurations of SrII and CoII cations, the fluorescence intensity of the MOFs is tuned from high emission to complete non‐emission. Sr‐ETTB with strong blue fluorescence shows reversible fluorescence variations in response to pressure and temperature, which is directly related to the reversible deformation of the crystal structure. In addition, non‐emissive Co‐ETTB counterpart exhibits a turn‐on fluorescent enhancement under the stimulation of analyte histidine. In the process, TPE‐cored linkers in the MOFs are released through competitive coordination substitution and subsequently reassembled to perform aggregation‐induced luminescence behavior originated from the organic linkers.
In Situ Raman Study of CO Electrooxidation on Pt(hkl) Single‐Crystal Surfaces in Acidic Solution
Authors: Su Min , Dong Jin‐Chao , Le Jia‐Bo , Zhao Yu , Yang Wei‐Min , Yang Zhi‐Lin , Attard Gary , Liu Guo‐Kun , Cheng Jun , Wei Yi‐Min , Tian Zhong‐Qun , Li Jian‐Feng
Published: September 2020

The adsorption and electrooxidation of CO molecules at well‐defined Pt(hkl) single‐crystal electrode surfaces is a key step towards addressing catalyst poisoning mechanisms in fuel cells. Herein, we employed in situ electrochemical shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) coupled with theoretical calculation to investigate CO electrooxidation on Pt(hkl) surfaces in acidic solution. We obtained the Raman signal of top‐ and bridge‐site adsorbed CO* molecules on Pt(111) and Pt(100). In contrast, on Pt(110) surfaces only top‐site adsorbed CO* was detected during the entire electrooxidation process. Direct spectroscopic evidence for OH* and COOH* species forming on Pt(100) and Pt(111) surfaces was afforded and confirmed subsequently via isotope substitution experiments and DFT calculations. In summary, the formation and adsorption of OH* and COOH* species plays a vital role in expediting the electrooxidation process, which relates with the pre‐oxidation peak of CO electrooxidation. This work deepens knowledge of the CO electrooxidation process and provides new perspectives for the design of anti‐poisoning and highly effective catalysts.
Direct Imaging of Atomic Permeation Through a Vacancy Defect in the Carbon Lattice
Authors: Cao Kecheng , Skowron Stephen T. , Stoppiello Craig T. , Biskupek Johannes , Khlobystov Andrei N. , Kaiser Ute
Published: September 2020

Porous graphene has shown promise as a new generation of selective membrane for sieving atoms, ions and molecules. However, the atomistic mechanisms of permeation through defects in the graphenic lattice are still unclear and remain unobserved in action, at the atomic level. Here, the direct observation of palladium atoms from a nanoparticle passing through a defect in a single‐walled carbon nanotube one‐by‐one has been achieved with atomic resolution in real time, revealing key stages of the atomic permeation. Bonding between the moving atom and dangling bonds around the orifice, immediately before and after passing through the subnano‐pore, plays an important role in the process. Curvature of the graphenic lattice crucially defines the direction of permeation from concave to convex side due to a difference in metal‐carbon bonding at the curved surfaces as confirmed by density functional theory calculations, demonstrating the potential of porous carbon nanotubes for atom sieving.
Kohlenstoff‐Kohlenstoff‐Kupplung auf inerten Oberflächen durch die Abscheidung von en route erzeugten Aryl Radikalen
Authors: Galeotti Gianluca , Fritton Massimo , Lackinger Markus
Published: September 2020

Zur Realisierung von C‐C‐Kupplungen in der Oberflächensynthese auf inerten Oberflächen haben wir eine Radikal‐Abscheidungs‐Quelle (RAQ) für die direkte Abscheidung von Aryl Radikalen auf beliebige Substrate entwickelt. Das Herzstück ist ein beheiztes reaktives Drift‐Rohr, durch das halogenierte Vorläufer abgeschieden und dabei en route in Radikale umgewandelt werden. Den Machbarkeitsbeweis erbringen wir mit 4,4′′‐Diiod‐p‐terphenyl (DITP)‐Vorläufern auf Iod‐passivierten Metall‐Oberflächen. Aus der Abscheidung mit der RAQ bei Raumtemperatur resultieren sehr regelmäßige Strukturen, die hauptsächlich aus monomeren (Terphenyl) oder dimeren (Sexiphenyl) Biradikalen bestehen. Mildes Heizen aktiviert die fortschreitende C‐C‐Kupplung in ausgedehntere molekulare Drähte. Diese Strukturen unterscheiden sich grundlegend von den nach konventioneller Abscheidung von intaktem DITP beobachteten selbst‐assemblierten Strukturen. Durch die direkte Abscheidung von Radikalen ist die Reaktivität des Substrats nicht mehr notwendig, und damit der Weg zur Synthese auf anwendungsrelevanten inerten Oberflächen geebnet.
Structural Characterization of N‐Linked Glycans in the Receptor Binding Domain of the SARS‐CoV‐2 Spike Protein and their Interactions with Human Lectins
Authors: Lenza Maria Pia , Oyenarte Iker , Diercks Tammo , Quintana Jon Imanol , Gimeno Ana , Coelho Helena , Diniz Ana , Peccati Francesca , Delgado Sandra , Bosch Alexandre , Valle Mikel , Millet Oscar , Abrescia Nicola G. A. , Palazón Asís , Marcelo Filipa , Jiménez‐Osés Gonzalo , Jiménez‐Barbero Jesús , Ardá Ana , Ereño‐Orbea June
Published: September 2020

The glycan structures of the receptor binding domain of the SARS‐CoV2 spike glycoprotein expressed in human HEK293F cells have been studied by using NMR. The different possible interacting epitopes have been deeply analysed and characterized, providing evidence of the presence of glycan structures not found in previous MS‐based analyses. The interaction of the RBD 13C‐labelled glycans with different human lectins, which are expressed in different organs and tissues that may be affected during the infection process, has also been evaluated by NMR. In particular, 15N‐labelled galectins (galectins‐3, ‐7 and ‐8 N‐terminal), Siglecs (Siglec‐8, Siglec‐10), and C‐type lectins (DC‐SIGN, MGL) have been employed. Complementary experiments from the glycoprotein perspective or from the lectin's point of view have permitted to disentangle the specific interacting epitopes in each case. Based on these findings, 3D models of the interacting complexes have been proposed.
Unveiling the Promotion of Surface‐Adsorbed Chalcogenate on the Electrocatalytic Oxygen Evolution Reaction
Authors: Shi Yanmei , Du Wei , Zhou Wei , Wang Changhong , Lu Shanshan , Lu Siyu , Zhang Bin
Published: September 2020

Transition metal chalcogenides (TMCs) are efficient oxygen evolution reaction (OER) pre‐electrocatalysts, and will in situ transform into metal (oxy)hydroxides under OER condition. However, the role of chalcogen is not fully elucidated after oxidation and severe leaching. Here we present the vital promotion of surface‐adsorbed chalcogenates on the OER activity. Taking NiSe2 as an example, in situ Raman spectroscopy revealed the oxidation of Se‐Se to selenites (SeO32−) then to selenates (SeO42−). Combining the severe Se leaching and the strong signal of selenates, it is assumed that the selenates are rich on the surface and play significant roles. As expected, adding selenites to the electrolyte of Ni(OH)2 dramatically enhance its OER activity. And sulfates also exhibit the similar effect, suggesting the promotion of surface‐adsorbed chalcogenates on OER is universal. Our findings offer unique insight into the transformation mechanism of materials during electrolysis.
Light‐Induced Efficient Hydroxylation of Benzene to Phenol by Quinolinium and Polyoxovanadate‐Based Supramolecular Catalysts
Authors: Gu Yaqi , Li Qi , Zang Dejin , Huang Yichao , Yu Han , Wei Yongge
Published: September 2020

Direct Hydroxylation of benzene to phenol with high yield and selectivity has been the goal of phenol industrial production. Photocatalysis can serve as a competitive method to realize the hydroxylation of benzene to phenol owing to its cost‐effective and environmental friendliness, however it is still a forbidding challenge to obtain good yield, high selectivity and high atom availability meanwhile. Here we show a series of supramolecular catalysts based on alkoxohexavanadate anions and quinolinium ions for the photocatalytic hydroxylation of benzene to phenol under UV irradiation. We demonstrate that polyoxoalkoxovanadates can serve as efficient catalysts which can not only stabilize quinolinium radicals but also reuse H2O2 produced by quinolinium ions under light irradiation to obtain excellent synergistic effect, including competitive good yield (50.1 %), high selectivity (>99 %) and high atom availability.
Highly Specific, Single‐step Cancer Cell Isolation with Multi‐Aptamer‐Mediated Proximity Ligation on Live Cell Membranes
Authors: Gao Qianqian , Zhao Yumeng , Xu Kangli , Zhang Chao , Ma Qian , Qi Liqing , Chao Dandan , Zheng Tingting , Yang Linlin , Miao Yanyan , Han Da
Published: September 2020

A single‐step method for isolation of specific cells based on multiple surface markers will have unique advantages because of its scalability, efficacy, and mildness. Herein, we developed multi‐aptamer‐mediated proximity ligation method on live cell membranes that leverages a multi‐receptor co‐recognition design for enhanced specificity, as well as a robust in situ signal amplification design for improved sensitivity of cell isolation. We demonstrated the promising efficacy of our method on differentiating tumor cell subtypes in both cell mixtures and clinical samples. Owing to its simple and fast operation with excellent cell isolation sensitivity and accuracy, this approach will have broad applications in biological science, biomedical engineering, and personalized medicine.
Electrochemical and Photoelectrochemical Water Oxidation for Hydrogen Peroxide Production
Authors: Xue Yudong , Wang Yunting , Pan Zhenhua , Sayama Kazuhiro
Published: September 2020

Hydrogen peroxide (H2O2), as a green fuel and oxidant, has drawn increasing attention in the energy and environmental research. Compared with the traditional anthraquinone process, the electrochemical (EC) and photoelectrochemical (PEC) syntheses of H2O2 are cost‐effective and environmentally friendly. In order to construct membraneless EC/PEC devices for the full H2O2 synthesis, anodic H2O2 production by water oxidation, which is less developed than cathodic H2O2 generation, is highly desirable. Here, we review recent developments for the EC/PEC H2O2 production by water oxidation, including fundamental aspects, benchmarking activity evaluation, material/catalyst selection, and strategies for increasing selectivity, efficiency, and accumulation. Furthermore, we discuss the challenges and outlook of water oxidation for H2O2 production, especially device‐level development, accumulation and stability, and industrial applications. Our review is intended to stimulate studies further improving EC/PEC H2O2 production.
Bonding Energetics of Palladium Amido/Aryloxide Complexes in DMSO: Implications for Palladium‐Mediated Aniline Activation
Authors: Wu Jun‐Yan , Li Zhen , Yang Jin‐Dong , Cheng Jin‐Pei
Published: September 2020

Thermodynamic knowledge of the metal–ligand (M−L) σ‐bond strength is crucial to understanding metal‐mediated transformations. Here, we developed a method for determining the Pd−X (X=OR and NHAr) bond heterolysis energies (ΔGhet(Pd−X)) in DMSO taking [(tmeda)PdArX] (tmeda=N,N,N′,N′‐tetramethylethylenediamine) as the model complexes. The ΔGhet(Pd−X) scales span a range of 2.6–9.0 kcal mol−1 for ΔGhet(Pd−O) values and of 14.5–19.5 kcal mol−1 for ΔGhet(Pd−N) values, respectively, implying a facile heterolytic detachment of the Pd ligands. Structure‐reactivity analyses of a modeling Pd‐mediated X−H bond activation reveal that the M−X bond metathesis is dominated by differences of the X−H and Pd−X bond strengths, the former being more influential. The ΔGhet(Pd−X) and pKa(X−H) parameters enable regulation of reaction thermodynamics and chemoselectivity and diagnosing the probability of aniline activation with Pd−X complexes.
Total Synthesis of Liangshanone
Authors: Huang Hong‐Xiu , Mi Fen , Li Chunxin , He Huan , Wang Feng‐Peng , Liu Xiao‐Yu , Qin Yong
Published: September 2020

The first total synthesis of liangshanone, a hexacyclic ent‐kaurane diterpenoid alkaloid, has been completed. Its intricate cagelike framework was assembled through several key transformations, including an oxidative dearomatization/Diels–Alder (OD/DA) cycloaddition sequence, a tandem alkene cleavage/Mannich cyclization, a Robinson‐type annulation, and an intramolecular aldol reaction. Notably, an organocatalytic enantioselective α‐hydroxymethylation process allowed the preparation of an enantiomerically enriched tricyclic intermediate that should enable asymmetric access to the target natural product.
High‐Voltage Rechargeable Alkali–Acid Zn–PbO2 Hybrid Battery
Authors: Xu Yunpeng , Cai Pingwei , Chen Kai , Ding Yichun , Chen Long , Chen Weifan , Wen Zhenhai
Published: September 2020

Aqueous rechargeable batteries have attracted attention owning to their advantages of safety, low cost, and sustainability, while the limited electrochemical stability window (1.23 V) of water leads to their failure in competition with organic‐based lithium‐ion batteries. Herein, we report an alkali–acid Zn–PbO2 hybrid aqueous battery obtained by coupling an alkaline Zn anode with an acidic PbO2 cathode. It shows the capability to deliver an impressively high open‐circuit voltage (Voc) of 3.09 V and an operate voltage of 2.95 V at 5 mA cm−2, thanks to the contribution of expanding the voltage window and the electrochemical neutralization energy from the alkali–acid asymmetric‐electrolyte hybrid cell. The hybrid battery can potentially deliver a large area capacity over 2 mAh cm−2 or a high energy density of 252.39 Wh kg−1 and shows almost no fading in area capacity over 250 charge–discharge cycles.
Biomimetic Approach for Highly Selective Artificial Water Channels Based on Tubular Pillar[5]arene Dimers
Authors: Strilets Dmytro , Fa Shixin , Hardiagon Arthur , Baaden Marc , Ogoshi Tomoki , Barboiu Mihail
Published: September 2020

Artificial water channels mimicking natural aquaporins (AQPs) can be used for selective and fast transport of water. Here, we quantify the transport performances of peralkyl‐carboxylate‐pillar[5]arenes dimers in bilayer membranes. They can transport ≈107 water molecules/channel/second, within one order of magnitude of the transport rates of AQPs, rejecting Na+ and K+ cations. The dimers have a tubular structure, superposing pillar[5]arene pores of 5 Å diameter with twisted carboxy‐phenyl pores of 2.8 Å diameter. This biomimetic platform, with variable pore dimensions within the same structure, offers size restriction reminiscent of natural proteins. It allows water molecules to selectively transit and prevents bigger hydrated cations from passing through the 2.8 Å pore. Molecular simulations prove that dimeric or multimeric honeycomb aggregates are stable in the membrane and form water pathways through the bilayer. Over time, a significant shift of the upper vs. lower layer occurs initiating new unexpected water permeation events through toroidal pores.
Carbon‐Carbon Coupling on Inert Surfaces by Deposition of En Route Generated Aryl Radicals
Authors: Galeotti Gianluca , Fritton Massimo , Lackinger Markus
Published: September 2020

To facilitate C−C coupling in on‐surface synthesis on inert surfaces, we devised a radical deposition source (RDS) for the direct deposition of aryl radicals onto arbitrary substrates. Its core piece is a heated reactive drift tube through which halogenated precursors are deposited and en route converted into radicals. For the proof of concept we study 4,4′′‐diiodo‐p‐terphenyl (DITP) precursors on iodine‐passivated metal surfaces. Deposition with the RDS at room temperature results in highly regular structures comprised of mostly monomeric (terphenyl) or dimeric (sexiphenyl) biradicals. Mild heating activates progressive C−C coupling into more extended molecular wires. These structures are distinctly different from the self‐assemblies observed upon conventional deposition of intact DITP. Direct deposition of radicals renders substrate reactivity unnecessary, thereby paving the road for synthesis on application‐relevant inert surfaces.
Salen–Mg‐doped NH2–MIL‐101(Cr) for effective CO2 adsorption under ambient conditions
Authors: Wu Xianhua , Lin Ji , Xie Jianxin , Zhao Xiaohui , Liu Dandan , Xing Yun , Xu Lixia
Published: September 2020

A novel metal‐doped metal–organic framework (MOF) was developed by incorporating salen–Mg into NH2–MIL‐101(Cr) structure under ambient conditions. The Schiff base complex was successfully prepared by condensing salicylaldehyde with a free amino group and then coordinating metal ions. Such a structure can endow the sample with higher CO2 adsorption performance. At 0°C and 1 bar, the salen–Mg‐modified sample achieves the maximum adsorption capacity of 2.18 mmol g−1 for CO2, which was 5.8% higher than the pristine salen–MOF under the same conditions. Notably, the Freundlich model indicates that the CO2 adsorption process of all samples conforms to reversible adsorption. However, the correlation coefficients (R2) of the Mg‐doped sample are lower than that of the pristine sample. Besides, the CO2/N2 adsorption selectivity and isosteric heat also show a similar trend. These results indicate that the salen–Mg can enhance the interaction between the material and CO2 molecules.
Fe3O4‐SAHPG‐Pd0 nanoparticles: A ligand‐free and low Pd loading quasiheterogeneous catalyst active for mild Suzuki–Miyaura coupling and CH activation of pyrimidine cores
Authors: Azizollahi Hamid , Eshghi Hossein , García‐López José‐Antonio
Published: September 2020

This paper reports a green magnetic quasiheterogeneous efficient palladium catalyst in which Pd0 nanoparticles have been immobilized in self‐assembled hyperbranched polyglycidole (SAHPG)‐coated magnetic Fe3O4 nanoparticles (Fe3O4‐SAHPG‐Pd0). This catalyst has been used for effective ligandless Pd catalyzed Suzuki–Miyaura coupling reactions of different aryl halides with substituted boronic acids at room temperature and in aqueous media. Herein, SAHPG is used as support; it also acts as a reducing agent and stabilizer to promote the transformation of PdII to Pd0 nanoparticles. Also, this environmental friendly quasiheterogeneous catalyst is employed for the first time in the synthesis of new pyrimido[4,5‐b]indoles via oxidative addition/CH activation reactions on the pyrimidine rings, which were obtained with higher yield and faster than when Pd(OAc)2 was used as the catalyst. Interestingly, the above‐mentioned catalyst could be recovered in a facile manner from the reaction mixture by applying an external magnet device and recycled several times with no significant decrease in the catalytic activity.
Enzyme Processing of Soy Flour with Minimized Protein Loss
Authors: Islam S. M. Mahfuzul , Loman Abdullah A. , Li Qian , Ju Lu‐Kwang
Published: September 2020

The enzymatic treatment of defatted soy flour (SF) to reduce indigestible carbohydrates can result in undesirable protein loss. Here protein loss was minimized with quantitation of the effects of ionic strength (IS), protease activity, and SF toasting. At the enzyme processing condition (25% w/v SF, 50 °C, pH 4.8, 48 hours), protein loss increased linearly with the IS in enzyme broths (EB); e.g., contacting untoasted SF with water or heat‐deactivated EB showed protein loss of 28% in water but up to 40% when IS was increased in the range of 0.04–0.19 M. Protein loss also increased with protease in EB (nondeactivated): after adjusted for IS‐related loss, approximately 10% and 25% additional protein loss occurred in EB of 73 and 490–557 U/(g SF) protease, respectively. SDS‐PAGE results showed that proteolysis was not extensive, mainly on β‐conglycinin α'/α and glycinin acidic 37‐kDa subunits; and most of the proteolytic products could be recovered by heat‐induced precipitation. SF toasting effects were studied, particularly at 2‐hours 160°C, with material balances, protein distributions, and monosaccharide yields in hydrolysates. Overall, protein loss was minimized to 5.2% and the conversion of carbohydrate to monomeric sugars increased to 89.2%.
Babassu Biodiesel Doped with Antioxidants: Assessment of Thermo‐Oxidative Stability by Borchardt and Daniels Method
Authors: de Mesquita Figueredo Igor , Tavares de Luna Francisco Murilo , Loureiro Cavalcante Célio , de Sousa Rios Maria Alexsandra
Published: September 2020

In this study, three antioxidants namely N,N′‐di‐sec‐butyl‐p‐phenylenediamine (PDA), 2,4,6‐Tri‐tert‐butylphenol/2,6‐Di‐tert‐butylphenol (IONOL), and unsaturated cardanol (U‐CDN) were added to babassu biodiesel (BB) at a concentration of 100 mg kg−1 to improve its oxidative stability. Differential Scanning Calorimetry (DSC) was used to evaluate the oxidative stability of the samples using synthetic air atmosphere and two temperatures (25 and 110 °C) instead of the conventional Rancimat method. The kinetic parameters were calculated according to Borchardt and Daniels method (ASTM E2041). All doped samples showed higher thermo‐oxidative stability when compared to pure babassu biodiesel with increasing activation energies of 66.5% for PDA, 19.4% for IONOL, and 3.9% for U‐CDN. At 25 °C, the babassu biodiesel showed a high oxidation reaction rate of 1.76 × 10−15 min−1. For the doped samples at the same temperature, that rate was reduced by a factor of 2, 200, and 3 × 108 times for U‐CDN, IONOL, and PDA, respectively. At 110 °C, the BB and the BB + U‐CDN samples showed high reaction rates, whereas the formulations with IONOL and PDA had rates reduced by 10 and 7.4 × 103 times, respectively. The thermal data showed R2 values higher than 0.99. All results confirmed the action of the antioxidants in retarding oxidation reactions in biodiesel. DSC is a promising alternative method for the determination of oxidative stability of biodiesel and its formulations with antioxidants.