bluuebunny/crossref_metadata_2025 huggingface dataset:
The Matteson Reaction
Authors: Matteson Donald S. , Collins Beatrice S. L. , Aggarwal Varinder K. , Ciganek Engelbert
Published: March 2021

The Matteson reaction is the nucleophilic displacement of a leaving group from the α‐carbon of an alkylboronic ester. The reaction proceeds through an (α‐haloalkyl)boronate complex, which decomposes via stereospecific 1,2‐migration and concomitant expulsion of the leaving group. Because the displacement is stereospecific and enantioenriched (α‐haloalkyl)boronic esters can be used, the reaction has become a valuable tool in the asymmetric synthesis of complex natural products. The enantioenriched (α‐haloalkyl)boronic esters themselves are accessed by addition of (dihaloalkyl)lithium reagents to chiral diol alkylboronic esters. Recent developments allow access to the key α‐substituted alkylboronates by the addition of configurationally stable chiral α‐lithioalkyl halides, carbamates, and benzoates to simple alkylboronic esters, considerably expanding the scope of the reaction. This chapter describes the mechanism of the Matteson reaction and related processes, along with its scope and limitations, and examples of its use in complex molecule synthesis.
Antibodies to Both Ro52 and Ro60 for Identifying Sjögren's Syndrome Patients Best Suited for Clinical Trials of Disease‐Modifying Therapies
Authors: Armağan Berkan , Robinson Susan A. , Bazoberry Adriana , Perin Jamie , Grader‐Beck Thomas , Akpek Esen K. , Kim Jean , Baer Alan N.
Published: March 2021

Objective

To assess anti‐Ro52 and anti‐Ro60 serologic profiles as markers of clinically relevant phenotypic subsets of patients with Sjögren's syndrome (SS).

Methods

From a cohort of 839 consecutive patients with suspected or established SS seen in our multidisciplinary SS center, we compared the association of key phenotypic features in 390 patients who fulfilled SS classification criteria and in the parent cohort, stratifed by the presence of both anti‐Ro60 and anti‐Ro52, anti‐Ro60 alone, and anti‐Ro52 alone.

Results

The SS cohort included 227 patients (58%) with both anti‐Ro60 and anti‐Ro52, 65 (17%) with anti‐Ro60 alone, 58 (15%) with anti‐Ro52 alone, and 40 (10%) with neither antibody. Those with both anti‐Ro60 and anti‐Ro52 had a significantly increased prevalence of abnormal ocular surface staining, focal lymphocytic sialadenitis with focus score ≥1, antinuclear antibody ≥1:320, anti‐SSB/La, rheumatoid factor, and IgG ≥15.6 gm/liter (P < 0.0016 for all). The groups with isolated anti‐Ro52 and anti‐Ro60 were equivalent to each other in their phenotypic associations, except for rheumatoid factor, which was higher in the anti‐Ro52 alone group. The associations of these Ro antibody serologic profiles were similar in the parent cohort, except for additional associations with salivary gland enlargement and parotid gland ultrasound score.

Conclusion

SS patients with both anti‐Ro60 and anti‐Ro52 antibodies are distinguished by a higher prevalence of markers of B‐cell hyperactivity and glandular inflammation. Antibody reactivity to both Ro60 and Ro52 may thus serve as an important inclusion criterion for SS patients in clinical trials where the therapeutic agent targets pathways mediating these pathogenic abnormalities.
Could marijuana legalization in Mexico force the hand of U.S. policy leaders?
Authors: Enos Gary
Published: March 2021

Lawmakers in Mexico appear on the verge of a momentous vote that would result in the United States finding itself wedged between two North American nations with legal marijuana markets. The extent to which Mexico's move could influence U.S. marijuana policy might depend in part on which house of Mexico's legislature holds the most influence on final bill language.
First‐Time Investigations on Cavitation in Rubber Parts Subjected to Constrained Tension Using In Situ Synchrotron X‐Ray Microtomography (SRμCT)
Authors: Euchler Eric , Bernhardt Ricardo , Wilde Fabian , Schneider Konrad , Heinrich Gert , Tada Toshio , Wießner Sven , Stommel Markus
Published: March 2021

Cavitation under constrained tension is a critical failure phenomenon in rubber parts. For laboratory tests, strain constraints can be generated using disk‐shaped rubber samples, that is, pancake specimens. Due to suppressed transverse contractibility, the dominating hydrostatic tensile stress, which is the highest in the center part of a pancake specimen, causes an internal failure process controlled by the formation and growth of cavities. Laboratory X‐ray microtomography (μCT) is a powerful tool to monitor the evolution of a cavity population considering various aspects of geometrical as well as microstructural constraints. In the case of carbon black–reinforced styrene‐butadiene rubber, microscopic cavities are surrounded by a region of significantly lower material density. Due to detection limits, this region cannot be analyzed in depth with μCT. In this study, synchrotron X‐ray microtomography (SRμCT) in combination with a modular load frame is used, for the first time, to investigate the damaging phenomenon of cavitation in rubbers. Due to the high phase contrast that can be achieved only by SRμCT, the microstructure of regions of lower material density can be analyzed and, as a result, tiny satellite cavities are identified in the walls of neighboring microscopic cavities.
Direct Ink Writing of Moldable Electrochemical Energy Storage Devices: Ongoing Progress, Challenges, and Prospects
Authors: Zhang Quanhai , Zhou Jiangqi , Chen Zhihong , Xu Chao , Tang Wei , Yang Guangzhi , Lai Chunyan , Xu Qunjie , Yang Junhe , Peng Chengxin
Published: March 2021

Among the advanced additive manufacturing technologies, direct ink writing (DIW) technology is extensively utilized to fabricate various energy storage devices (i.e., batteries, supercapacitors [SCs], and solar cells) due to its excellent process flexibility, excellent geometric controllability, as well as relative low‐cost and efficient processes. DIW offers a convenient way to build 3D structures for energy storage devices and provide higher power density and energy density in comparison with traditional casting techniques. Herein, the recent advances in DIW for emerging energy storage devices, including SCs, lithium‐ion batteries, lithium–sulfur batteries, rechargeable lithium metal batteries, and solid‐state batteries, are emphasized and discussed. The significant achievements made developing printed energy storage devices, such as printing ink materials, designing the printing process, and the great progress in terms of the corresponding electrochemical performances, are also highlighted. Finally, the major challenges and potential research possibilities in 3D printing energy storage device are proposed. It can be expected that, as 3D printing technology develops, batteries and SCs with durable lifespans, favorable safety, as well as high energy density and power density will eventually be utilized in many fields.
Carbon‐Supported High‐Entropy Oxide Nanoparticles as Stable Electrocatalysts for Oxygen Reduction Reactions
Authors: Li Tangyuan , Yao Yonggang , Ko Byung Hee , Huang Zhennan , Dong Qi , Gao Jinlong , Chen Wilson , Li Jianguo , Li Shuke , Wang Xizheng , Shahbazian‐Yassar Reza , Jiao Feng , Hu Liangbing
Published: March 2021

Nanoparticles supported on carbonaceous substrates are promising electrocatalysts. However, achieving good stability for the electrocatalysts during long‐term operations while maintaining high activity remains a grand challenge. Herein, a highly stable and active electrocatalyst featuring high‐entropy oxide (HEO) nanoparticles uniformly dispersed on commercial carbon black is reported, which is synthesized via rapid high‐temperature heating (≈1 s, 1400 K). Notably, the HEO nanoparticles with a record‐high entropy are composed of ten metal elements (i.e., Hf, Zr, La, V, Ce, Ti, Nd, Gd, Y, and Pd). The rapid high‐temperature synthesis can tailor structural stability and avoid nanoparticle detachment or agglomeration. Meanwhile, the high‐entropy design can enhance chemical stability to prevent elemental segregation. Using oxygen reduction reaction as a model, the 10‐element HEO exhibits good activity and greatly enhances stability (i.e., 92% and 86% retention after 12 and 100 h, respectively) compared to the commercial Pd/C electrocatalyst (i.e., 76% retention after 12 h). This superior performance is attributed to the high‐entropy compositional design and synthetic approach, which offers an entropy stabilization effect and strong interfacial bonding between the nanoparticles and carbon substrate. The approach promises a viable route toward synthesizing carbon‐supported high‐entropy electrocatalysts with good stability and high activity for various applications.
Air‐Stable Self‐Powered Photodetectors Based on Lead‐Free CsBi3I10/SnO2 Heterojunction for Weak Light Detection
Authors: Hao Dandan , Liu Dapeng , Shen Yukuan , Shi Qianqian , Huang Jia
Published: March 2021

Lead halide perovskites (LHPs) have been widely investigated in photodetection applications owing to their intriguing optoelectronic properties. However, the application of LHPs‐based photodetectors (PDs) is hindered because of the toxicity of lead and instability in ambient air. Here, an air‐stable self‐powered photodetector is designed based on all‐inorganic lead‐free CsBi3I10/SnO2 heterojunction. The device exhibits broad spectral response in both UV and visible light, fast response on µs scale, and decent long‐term stability. The device holds a faster response speed (tr/td = 7.8/8.8 µs), among the best reported self‐powered lead‐free perovskites photodetectors. More importantly, the device can display obvious photoresponses even under ultra‐weak light intensity as low as 10 pW cm–2, showing better weak‐light sensitivity than previously reported lead‐free perovskites photodetectors, to the best of our knowledge. Moreover, the device holds good air stability in the 73 days test without encapsulation. These results suggest that CsBi3I10/SnO2‐based self‐powered PDs with high photodetection capability possess enormous potential in stable and broadband PDs for weak light detection in the future.
Inter‐Sample and Intra‐Sample Variability in Electronic Properties of Methylammonium Lead Iodide
Authors: Hong Min Ji , Labram John G.
Published: March 2021

While the challenges associated with the stability of metal halide perovskites are well known and intensely studied, variability in electronic properties represents an equally significant, yet seldom studied, challenge that could potentially slow or inhibit the commercial viability of these systems. In this work, the contactless characterization technique time‐resolved microwave conductivity (TRMC) is used to quantify the variability in electronic properties of the prototypical perovskite, methylammonium lead iodide (MAPbI3) both between different samples, and at different locations within the same sample. Using scanning electron microscopy (SEM) and a quasi‐automated image‐analysis strategy, it is possible to evaluate the metrics of heterogeneity in surface microstructure and correlate them with the electronic properties as obtained by TRMC. Substantial intra‐sample and inter‐sample variation is observed in the mobility‐yield product in samples prepared following differing protocols, and in samples prepared following identical protocols.
Plasmonic Alloys Reveal a Distinct Metabolic Phenotype of Early Gastric Cancer
Authors: Su Haiyang , Li Xinxing , Huang Lin , Cao Jing , Zhang Mengji , Vedarethinam Vadanasundari , Di Wen , Hu Zhiqian , Qian Kun
Published: March 2021

Gastric cancer (GC) is a multifactorial process, accompanied by alterations in metabolic pathways. Non‐invasive metabolic profiling facilitates GC diagnosis at early stage leading to an improved prognostic outcome. Herein, mesoporous PdPtAu alloys are designed to characterize the metabolic profiles in human blood. The elemental composition is optimized with heterogeneous surface plasmonic resonance, offering preferred charge transfer for photoinduced desorption/ionization and enhanced photothermal conversion for thermally driven desorption. The surface structure of PdPtAu is further tuned with controlled mesopores, accommodating metabolites only, rather than large interfering compounds. Consequently, the optimized PdPtAu alloy yields direct metabolic fingerprints by laser desorption/ionization mass spectrometry in seconds, consuming 500 nL of native plasma. A distinct metabolic phenotype is revealed for early GC by sparse learning, resulting in precise GC diagnosis with an area under the curve of 0.942. It is envisioned that the plasmonic alloy will open up a new era of minimally invasive blood analysis to improve the surveillance of cancer patients in the clinical setting.
Progress in High‐Performance Anion Exchange Membranes Based on the Design of Stable Cations for Alkaline Fuel Cells
Authors: Tao Zhengwang , Wang Chenyi , Zhao Xiaoyan , Li Jian , Guiver Michael D.
Published: March 2021

Solid alkaline fuel cells with anion exchange membranes (AEMs) have drawn wide attention and have become an important focus in the field of renewable energy cells in recent years due to their high electrode activity, potential application of non‐precious metal catalysts, and relatively low requirements for fuel purity. AEM is the central component in solid alkaline fuel cells, and plays the role of conducting ions, blocking fuel crossover and providing catalyst support in fuel cells. Its performance directly affects the efficiency and service life of fuel cells. With some exceptions, the majority of AEMs have relatively low hydroxide conductivity and poor durability, which cannot meet the requirements of practical applications. The past decade has witnessed great progress in AEM designs and stability. Various kinds of AEMs with different cationic structures have been designed, and their properties and application in fuel cells are investigated. This review provides a comparative investigation and summary of highlights from the design of cationic structures for AEMs, including cyclic and spirocyclic quaternary ammonium cations, modified quaternary phosphonium, modified imidazoles, guanidinium, and metal cations. The authors’ perspective on the remaining challenges and directions of AEMs research for future development are also discussed.
Optical Outcoupling Efficiency of Organic Light‐Emitting Diodes with a Broad Recombination Profile
Authors: Li Yungui , Kotadiya Naresh B. , van der Zee Bas , Blom Paul W. M. , Wetzelaer Gert‐Jan A. H.
Published: March 2021

Although a broadened recombination zone is beneficial for the lifetime of organic light‐emitting diodes (OLEDs), its effect on the optical outcoupling efficiency is unknown. Here, a numerical model to simulate the fraction of photons coupled to air for devices with a broad recombination zone is presented. It is demonstrated that the total outcoupling can be calculated as the integral of the outcoupling efficiency over different positions of emitting dipoles, weighted by the sum‐normalized recombination profile, as obtained from electrical modeling. Using single‐layer OLEDs based on the thermally delayed activated fluorescence emitter 9,10‐bis(4‐(9H‐carbazol‐9‐yl)‐2,6‐dimethylphenyl)‐9,10‐diboraanthracene (CzDBA) as a model system, it is demonstrated that an outcoupling efficiency to the air mode as high as ≈26% can be obtained. These simulations are validated with experiments on CzDBA OLEDs of different thickness. The results show that single‐layer devices with a broadened emission zone can achieve similar outcoupling efficiency to multilayer OLEDs with an optimized confined emission zone, establishing a route to efficient, stable, and simplified OLEDs.
Confined Synthesis of Stable and Uniform CsPbBr3 Nanocrystals with High Quantum Yield up to 90% by High Temperature Solid‐State Reaction
Authors: Zhang Qinggang , Zheng Weilin , Wan Qun , Liu Mingming , Feng Xiuping , Kong Long , Li Liang
Published: March 2021

For the display applications of perovskite nanocrystals (NCs), the photoluminescence quantum yield (PLQY), emission linewidth, and operational stability are the main parameters that directly affect the performance of the optoelectronic device. High‐temperature solid‐state synthesis has been regarded as an eco‐friendlier process to prepare perovskite NCs than colloidal synthesis. However, it is relatively difficult to control the sizes and size distribution of NCs at high temperatures, which usually results in a lower PLQY and wider emission. Here, highly stable CsPbBr3 NCs with a high PLQY up to 93% and a narrow emission linewidth of 18 nm are successfully prepared by a hard‐template solid‐state synthesis at high temperature (600 °C). It is found that the precisely confined growth of NCs in the thermally stable and uniform pores of the mesoporous silica (MS) template is the main reason to achieve the high PLQY and narrow emission, and the pre‐hydrolysis sealing strategy contributes to the exceptional stability. More surprisingly, the emission peak intensity of CsPbBr3/MS@SiO2 is 3.8 times higher than that of the commercialized silicate green phosphor when encapsulated on the blue‐chip with the same absorbance at 450 nm, which makes it an ideal down‐conversion emitter for display applications.
Perspectives of Organic and Perovskite‐Based Spintronics
Authors: Privitera Alberto , Righetto Marcello , Cacialli Franco , Riede Moritz K.
Published: March 2021

Spin‐related phenomena in optoelectronic materials can revolutionize several technological applications in the areas of data processing and storage, quantum computing, lighting, energy harvesting, sensing, and healthcare. A fundamental boost to this promising field can be envisaged thanks to the use of two emerging materials, which have recently been receiving increasing scientific attention: organic semiconductors (OSCs) and halide perovskites (HPs). Here, the first progress in the resulting fields, organic‐ and perovskite‐based spintronics, is reviewed, which will enable the manipulation of spin, charges, and photons in spin/optoelectronic devices. A link between these two classes of materials is created by highlighting the pros and cons of each technology, and their potential applications in new multifunctional spintronic devices are discussed. Current challenges in the field are also outlined, and convenient approaches to overcome them are proposed.
Physical Vapor Deposition in Solid‐State Battery Development: From Materials to Devices
Authors: Lobe Sandra , Bauer Alexander , Uhlenbruck Sven , Fattakhova‐Rohlfing Dina
Published: March 2021

This review discusses the contribution of physical vapor deposition (PVD) processes to the development of electrochemical energy storage systems with emphasis on solid‐state batteries. A brief overview of different PVD technologies and details highlighting the utility of PVD for the fabrication and characterization of individual battery materials are provided. In this context, the key methods that have been developed for the fabrication of solid electrolytes and active electrode materials with well‐defined properties are described, and demonstrations of how these techniques facilitate the in‐depth understanding of fundamental material properties and interfacial phenomena as well as the development of new materials are provided. Beyond the discussion of single components and interfaces, the progress on the device scale is also presented. State‐of‐the‐art solid‐state batteries, both academic and commercial types, are assessed in view of energy and power density as well as long‐term stability. Finally, recent efforts to improve the power and energy density through the development of 3D‐structured cells and the investigation of bulk cells are discussed.
Intrinsically Nonflammable Ionic Liquid‐Based Localized Highly Concentrated Electrolytes Enable High‐Performance Li‐Metal Batteries
Authors: Wang Zhicheng , Zhang Fengrui , Sun Yiyang , Zheng Lei , Shen Yanbin , Fu Daosong , Li Wanfei , Pan Anran , Wang Lei , Xu Jingjing , Hu Jianchen , Wu Xiaodong
Published: March 2021

The development of high‐performance Li‐metal batteries (LMBs) requires advanced electrolytes that simultaneously possess high safety, high ionic conductivity, wide electrochemical window, and good ability to suppress Li dendrite growth. Herein an intrinsically nonflammable ionic liquid‐based localized highly concentrated electrolyte (LHCE) composed of lithium bis(fluorosulfonyl)imide (LiFSI) salt, N‐methyl‐N‐propyl‐piperidinium bis(fluorosulfonyl)imide ([PP13][FSI]) as ionic liquid solvent, and 1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropylether (HFE) as diluent solvent is designed. The introduction of HFE greatly decreases the viscosity and cost of the pure ionic liquid electrolyte, improves its ionic conductivity, and enhances its ability to wet the separator surface. The Li+ solvation structure, Li deposition behavior, and formation of the solid electrolyte interphase (SEI) layer in LHCE are systematically investigated by using Raman spectroscopy, theoretical simulations, scanning electron microscopy, and X‐ray photoelectron spectroscopy. A rational mechanism is suggested for the stable SEI formation and the homogeneous Li deposition behavior. Due to its excellent ability to suppress Li dendrites, the LHCE exhibits a high average Coulombic efficiency (99.4% over 800 cycles in the Cu/Li cell), extremely stable cycling performance (10 mA cm−2 over 5000 cycles in the Li/Li symmetric cell), and excellent cycling performance and rate capability in the LMB systems of LiFePO4 (LFP)/Li and LFP/Li@Cu.
Metal/Covalent‐Organic Framework Based Cathodes for Metal‐Ion Batteries
Authors: Kong Lingjun , Liu Ming , Huang Hui , Xu Yunhua , Bu Xian‐He
Published: March 2021

Metal‐organic frameworks (MOFs) and covalent‐organic frameworks (COFs) are two emerging families of functional materials used in many fields. Advantages of both include compositional designability, structural diversity, and high porosity, which offer immense possibilities in the search for high‐performance electrode materials for metal‐ion batteries. A large number of MOF/COF‐based cathode materials have been reported. Despite these advantageous features and research advances, MOFs/COFs and their derivatives face various challenges as cathode materials. In this review, an overview of the progress of MOF/COF‐based cathodes for advanced metal‐ion batteries is presented, including lithium‐ion batteries and other nascent technologies, such as sodium‐ion batteries, zinc‐ion batteries, aluminum‐ion batteries, and magnesium‐ion batteries. Research advances on the cathodes of MOFs/COFs and their derivatives are summarized in terms of active sites, structural design, and protective coatings. Perspectives and directions on the future development of MOF/COF‐based cathodes are outlined for meeting the requirements of practical applications.
Mass transfer in 3D‐printed electrolyzers: The importance of inlet effects
Authors: Weusten Stéphane J. C. , Murrer Luc C. E. M. , de Groot Matheus T. , van der Schaaf John
Published: March 2021

This article investigates the effect of inlet shape, entrance length, and turbulence promoters on mass transfer by using 3D‐printed electrolyzers. Our results show that the inlet design can promote turbulence and lead to an earlier transition to turbulent flow. The Reynolds number at which the transition occurs can be predicted by the ratio of the cross‐sectional area of the inlet to the cross‐sectional area of the electrolyzer channel. A longer entrance length results in more laminar behavior and a later transition to turbulent flow. With an entrance length of 550 mm, the inlet design did no longer affect the mass transfer performance significantly. The addition of gyroid type turbulence promoters resulted in a factor of 2 to 4 increase in mass transfer depending on inlet design, entrance length, and the type of promoter. From one configuration to another, there was a minimal variation in pressure drop (<1600 Pa).
Advances in genomic diagnosis of a large cohort of Egyptian patients with disorders of sex development
Authors: Mazen Inas , Mekkawy Mona , Kamel Alaa , Essawi Mona , Hassan Heba , Abdel‐Hamid Mohamed , Amr Khalda , Soliman Hala , El‐Ruby Mona , Torky Ahmed , El Gammal Mona , Elaidy Aya , Bashamboo Anu , McElreavey Kenneth
Published: March 2021

Disorders/differences of sex development (DSD) comprise a group of congenital disorders that affect the genitourinary tract and usually involve the endocrine and reproductive system. The aim of this work was to identify genetic variants responsible for disorders of human urogenital development in a cohort of Egyptian patients. This three‐year study included 225 patients with various DSD forms, referred to the genetic DSD and endocrinology clinic, National Research Centre, Egypt. The patients underwent thorough clinical examination, hormonal and imaging studies, detailed cytogenetic and fluorescence in situ hybridization analysis, and molecular sequencing of genes known to commonly cause DSD including AR, SRD5A2, 17BHSD3, NR5A1, SRY, and WT1. Whole exome sequencing (WES) was carried out for 18 selected patients. The study revealed a high rate of sex chromosomal DSD (33%) with a wide array of cytogenetic abnormalities. Sanger sequencing identified pathogenic variants in 33.7% of 46,XY patients, while the detection rate of WES reached 66.7%. Our patients showed a different mutational profile compared with that reported in other populations with a predominance of heritable DSD causes. WES identified rare and novel pathogenic variants in NR5A1, WT1, HHAT, CYP19A1, AMH, AMHR2, and FANCA and in the X‐linked genes ARX and KDM6A. In addition, digenic inheritance was observed in two of our patients and was suggested to be a cause of the phenotypic variability observed in DSD.
General, Divergent Platform for Diastereoselective Synthesis of trans‐Cyclooctenes with High Reactivity and Favorable Physiochemical Properties**
Authors: Pigga Jessica E. , Rosenberger Julia E. , Jemas Andrew , Boyd Samantha J. , Dmitrenko Olga , Xie Yixin , Fox Joseph M.
Published: March 2021

trans‐Cyclooctenes (TCOs) are essential partners in the fastest known bioorthogonal reactions, but current synthetic methods are limited by poor diastereoselectivity. Especially hard to access are hydrophilic TCOs with favorable physicochemical properties for live cell or in vivo experiments. Described is a new class of TCOs, “a‐TCOs”, prepared in high yield by stereocontrolled 1,2‐additions of nucleophiles to trans‐cyclooct‐4‐enone, which itself was prepared on a large scale in two steps from 1,5‐cyclooctadiene. Computational transition‐state models rationalize the diastereoselectivity of 1,2‐additions to deliver a‐TCO products, which were also shown to be more reactive than standard TCOs and less hydrophobic than even a trans‐oxocene analogue. Illustrating the favorable physicochemical properties of a‐TCOs, a fluorescent TAMRA derivative in live HeLa cells was shown to be cell‐permeable through intracellular Diels–Alder chemistry and to wash out more rapidly than other TCOs.
Aptamer Switches Regulated by Post‐Transition/Transition Metal Ions
Authors: Billet Blandine , Chovelon Benoit , Fiore Emmanuelle , Oukacine Farid , Petrillo Mel‐Alexandre , Faure Patrice , Ravelet Corinne , Peyrin Eric
Published: March 2021

We introduced an aptamer switch design that relies on the ability of post‐transition/transition metal ions to trigger, through their coordination to nucleobases, substantial DNA destabilization. In the absence of molecular target, the addition of one such metal ion to usual aptamer working solutions promotes the formation of an alternative, inert DNA state. Upon exposure to the cognate compound, the equilibrium is shifted towards the competent DNA form. The switching process was preferentially activated by metal ions of intermediate base over phosphate complexation preference (i.e. Pb2+, Cd2+) and operated with diversely structured DNA molecules. This very simple aptamer switch scheme was applied to the detection of small organics using the fluorescence anisotropy readout mode. We envision that the approach could be adapted to a variety of signalling methods that report on changes in the surface charge density of DNA receptors.
Controlling Oxygen Reduction Selectivity through Steric Effects: Electrocatalytic Two‐Electron and Four‐Electron Oxygen Reduction with Cobalt Porphyrin Atropisomers
Authors: Lv Bin , Li Xialiang , Guo Kai , Ma Jun , Wang Yanzhi , Lei Haitao , Wang Fang , Jin Xiaotong , Zhang Qingxin , Zhang Wei , Long Ran , Xiong Yujie , Apfel Ulf‐Peter , Cao Rui
Published: March 2021

Achieving a selective 2 e− or 4 e− oxygen reduction reaction (ORR) is critical but challenging. Herein, we report controlling ORR selectivity of Co porphyrins by tuning only steric effects. We designed Co porphyrin 1 with meso‐phenyls each bearing a bulky ortho‐amido group. Due to the resulted steric hinderance, 1 has four atropisomers with similar electronic structures but dissimilar steric effects. Isomers αβαβ and αααα catalyze ORR with n=2.10 and 3.75 (n is the electron number transferred per O2), respectively, but ααββ and αααβ show poor selectivity with n=2.89–3.10. Isomer αβαβ catalyzes 2 e− ORR by preventing a bimolecular O2 activation path, while αααα improves 4 e− ORR selectivity by improving O2 binding at its pocket, a feature confirmed by spectroscopy methods, including O K‐edge near‐edge X‐ray absorption fine structure. This work represents an unparalleled example to improve 2 e− and 4 e− ORR by tuning only steric effects without changing molecular and electronic structures.
Circulatory histidine levels as predictive indicators of disease activity in takayasu arteritis
Authors: Kumar Umesh , Mehta Pankti , Kumar Sandeep , Jain Avinash , Guleria Anupam , Kumar R Venkatesh , Misra Ramnath , Kumar Dinesh
Published: March 2021

Background and objective

Quantitative assessment of disease activity is important for effective management of patients with autoimmune inflammatory diseases (AIDs) including Takayasu arteritis (TA).  Histidine supplementation alleviates inflammation and has strong anti‐oxidative effects as well. The present study aims to evaluate the diagnostic potential of circulatory histidine for predicting disease activity in TA.

Methods

The serum metabolic profiles on 98 TA‐patients and 77 normal controls (NC) samples were measured at high‐resolution 800 MHz NMR spectrometer employing standard 1D‐1H‐CPMG NMR experiments. The NMR spectral data were processed and concentrations of histidine and other circulatory metabolites were estimated with respect to formate (as an internal reference) and compared using ANOVA based on Tukey's multiple comparison test and statistical significance was considered at P‐value < 0.05. The correlations of histidine with plasma CRP and ESR levels were evaluated using Spearman‐r method. Data were expressed as median (interquartile‐range [IQR]).

Results

Histidine levels were significantly decreased in active TA patients (23.90; IQR:16.10) compared to both inactive TA patients (35.50, IQR:24.30) and NC (42.80, IQR:22.10), whereas there was no significant difference between inactive TA and NC. For TA patients, the histidine levels correlated negatively with clinical markers of inflammation, that is, ESR (r = ‐0.19, P < .078) and with the CRP (r = ‐0.26, P < .013). Further, the receiver‐operating‐characteristic (ROC) curve analysis was performed to test the diagnostic potential of histidine for differentiating active from inactive disease. The area under the ROC curve (AUROC) value equal to 0.65 [95% CI = 0.54‐0.76] revealed its moderate discriminatory ability. Compared to other circulatory metabolites, the discriminatory performance of histidine was also found to be in the moderate range (highest AUROC‐value of 0.76 was found for glutamine‐to‐glucose ratio (QGR).

Conclusion

The study demonstrated the altered circulatory histidine levels in TA patients that may serve as a surrogate marker for improving the diagnostic screening of active and inactive TA patients.
Superior Pebax‐1657/amine‐modified halloysite nanotubes mixed‐matrix membranes to improve the CO2/CH4 separation efficiency
Authors: Ahmadi Seyed Mohammad Ali , Mohammadi Toraj , Azizi Navid
Published: March 2021

In the present study, halloysite nanotubes (HNTs) were firstly functionalized using N‐β‐(aminoethyl)‐γ‐aminopropyltrimethoxy silane and then employed as nanofillers to fabricate mixed‐matrix membranes including poly (ether‐block‐amide) polymer as the primary material. To characterize the HNTs, as well as the obtained membranes, thermal gravimetric analysis, Fourier‐transform infrared spectroscopy, X‐ray powder diffraction, and Field emission scanning electron microscopy analyses were employed. Effects of the modified and pure HNTs loadings, as well as feed pressure on CH4 and CO2 permeabilities and ideal CO2/CH4 selectivity of the prepared membranes, were surveyed. The experimental permeation results indicated that incorporation of 1.5 wt% of amine‐functionalized HNTs into the polymer matrix improves CO2 permeability and the ideal selectivity by nearly 37 and 24%, respectively, due to the higher CO2 adsorption capacity of the amine‐functionalized HNTs.
An effective computational‐screening strategy for simultaneously improving both catalytic activity and thermostability of α‐l‐rhamnosidase
Authors: Li Lijun , Li Wenjing , Gong Jianye , Xu Yanyan , Wu Zheyu , Jiang Zedong , Cheng Yi‐Sheng , Li Qingbiao , Ni Hui
Published: March 2021

Catalytic efficiency and thermostability are the two most important characteristics of enzymes. However, it is always tough to improve both catalytic efficiency and thermostability of enzymes simultaneously. In the present study, a computational strategy with double‐screening steps was proposed to simultaneously improve both catalysis efficiency and thermostability of enzymes; and a fungal α‐l‐rhamnosidase was used to validate the strategy. As the result, by molecular docking and sequence alignment analysis within the binding pocket, seven mutant candidates were predicted with better catalytic efficiency. By energy variety analysis, A355N, S356Y, and D525N among the seven mutant candidates were predicted with better thermostability. The expression and characterization results showed the mutant D525N had significant improvements in both enzyme activity and thermostability. Molecular dynamics simulations indicated that the mutations located within the 5 Å range of the catalytic domain, which could improve root mean squared deviation, electrostatic, Van der Waal interaction, and polar salvation values, and formed water bridge between the substrate and the enzyme. The study indicated that the computational strategy based on the binding energy, conservation degree and mutation energy analyses was effective to develop enzymes with better catalysis and thermostability, providing practical approach for developing industrial enzymes.
Identification of MEG8/miR‐378d/SOBP axis as a novel regulatory network and associated with immune infiltrates in ovarian carcinoma by integrated bioinformatics analysis
Authors: Lei Jian , He Zhen‐Yu , Wang Jun , Hu Min , Zhou Ping , Lian Chen‐Lu , Hua Li , Wu San‐Gang , Zhou Juan
Published: March 2021

Background

To investigate the potential molecular mechanism of ovarian cancer (OC) evolution and immunological correlation using the integrated bioinformatics analysis.

Methods

Data from the Gene Expression Omnibus was used to gain differentially expressed genes (DEGs). Gene Ontology and Kyoto Encyclopedia of Gene and Genome pathway analysis were completed by utilizing the Database for Annotation, Visualization, and Integrated Discovery. After multiple validations via The Cancer Genome Atlas (TCGA), Genotype‐Tissue Expression (GTEx) projects, the Human Protein Atlas, Kaplan–Meier (KM) plotter, and immune logical relationships of the key gene SOBP were evaluated based on Tumor Immune Estimation Resource, and Gene Set Enrichment Analysis (GSEA) software. Finally, the lncRNAs‐miRNAs‐mRNAs subnetwork was predicted by starBase, TargetScan, miRBD, and LncBase, individually. Correlation of expression and prognosis for mRNAs, miRNAs, and lncRNAs were confirmed by TCGA, Gene Expression Profiling Interactive Analysis 2 (GEPIA 2), starBase, and KM.

Results

A total of 192 shared DEGs were discovered from the four data sets, including 125 upregulated and 67 downregulated genes. Functional enrichment analysis presented that they were mainly enriched in cartilage development, pathway in PI3 K‐Akt signaling pathway. Lower expression of SOBP was the independent prognostic factor for inferior prognosis in OC patients. The downregulation of SOBP enhanced the infiltration levels of B cells, CD8+ T cells, Macrophage, Neutrophil, and Dendritic cells. GSEA also disclosed low SOBP showed a significantly associated with the activation of various immune‐related pathways. Finally, we first reported that the MEG8/miR‐378d/SOBP axis was linked to the development and prognosis of OC through regulating the cytokines pathway.

Conclusions

Our study establishes a novel MEG8/miR‐378d/SOBP axis in the development and prognosis of OC, and the triple subnetwork probably affects the progression of the OC by regulating the cytokines pathway.
Ridge augmentation—The new field of computerized guided surgery: A technical note for minimal‐invasive bone splitting
Authors: Alevizakos Vasilios , Mitov Gergo , Schiller Marcus , von See Constantin
Published: March 2021

Different instrumentation procedures of the alveolar ridge expansion technique (ARST) with or without Guided Bone Regeneration have proven to be effective for successful implant placement in cases of alveolar bone width between 3mm and 6mm. Conventional bone splitting techniques require flap arising. This technical note demonstrates a method for flapless guided bone splitting. For this purpose, a newly developed surgical guide with internal irrigation channels was used.

Using CAD‐CAM additive technology, a narrow slot along the field of interest and a pin of a cooling pipe was designed and implemented in a surgical guide template. The bone split was performed flapless through the surgical guide while the cooling pipe was connected to it.

During surgery, the piezo‐driven instrument was moved within that slot, and the irrigation solution was directly rinsing it at point of entry through the irrigation channel. This procedure was performed on a 3.3 mm wide alveolar ridge achieving over 3 mm of bone gain.

The described method combines several positive aspects. The micro‐invasive flapless surgical procedure might improve postoperative healing. Additionally, sufficient cooling of the bone might lead to less thermal affection of bone cells and less resorption of the cortical bone. However, systematic studies are needed to confirm the observations of the presented case report.
Performance of a Fixed‐Bed Bioreactor Using Diatom Biofilms for Wastewater Bioremediation
Authors: Chaib Nadjla , Dzizi Sabrina , Kaddeche Hadjer , Noune Faiza
Published: March 2021

This present study aims to demonstrate the efficiency of a simple biological wastewater treatment process using diatoms for removing mainly nitrogen and phosphorus from four types of effluents: synthetic wastewater (SW), a real urban effluent (RUE), industrial effluent (IE), and agricultural sewage (AS). The process consists of promoting the attachment of diatoms to several grain sizes to form biofilms, to define the best grain size for the performance and to study the evolution of diatom biofilms and some parameters, such as ammonium, nitrate, phosphorus, and chemical oxygen demand (COD). Diatoms used in this study are collected from the highest rate of biomass growth of diatoms grown in an experimental photobioreactor. Initially, four fixed‐bed bioreactors in batch mode are experienced over artificial conditions and filled with coarse sand (B1), small gravel (B2), medium gravel (B3), and coarse gravel (B4). The bioreactor B2 is selected to study the evolution of nutrients for the four types of wastewater. The best removal rates are measured as 75.26% for ammonium, 72.43% for nitrate, and 61.65% for phosphorus for SW. Important rates of COD are also recorded for RUE (75.29%). These results demonstrate that nutrients in the wastewater can be successfully removed by diatom biofilms.
COVID‐19 in cancer patients may be presented by atypical symptoms and higher mortality rate, a case‐controlled study from Iran
Authors: Shahidsales Soodabeh , Aledavood Seyed Amir , Joudi Mona , Molaie Fatemeh , Esmaily Habibollah , Javadinia Seyed Alireza
Published: March 2021

Background

Coronavirus disease 2019 (COVID‐19) pandemic imposes serious problems to health systems around the world and its rapid expansion makes it difficult to serve patients with certain health conditions such as cancer patients which might be at high risk for mortality if they are infected by the severe acute respiratory syndrome coronavirus 2.

Aim

To compare the outcomes of cancer patients admitted due to COVID‐19 and compare them with data of COVID‐19 infected patients without a history of cancer.

Methods

In this case‐controlled study, 93 healthy people and 92 patients with malignancy admitted for COVID‐19 were enrolled. The clinical features and laboratory indicators were assessed at the presentation and both groups were followed‐up for treatment options and outcomes prospectively and compared at the level of P ≤ .05.

Results

COVID‐19 related mortality rate in malignant patients was significantly higher than patients without malignancy (41.3% vs 17.2%, P = .0001). The risk of death increased significantly in patients with malignancy (OR = 8.4, P = .007) and mechanical ventilation (OR = 3.3, P = .034) independent of other variables. Fever (64.5% vs 43.5%, P = .004), chill (35.5% vs 14.1%, P = .001), malaise (49.5% and 30.4%, P = .008), dry cough (51.6% vs 26.1%, P = .0001), and vomiting (17.2% vs 5.4%, P = .012) were reported significantly lower in cancer patients.

Conclusion

The results suggest that cancer patients who were infected by COVID‐19 may present with atypical symptoms are at higher risk of mortality independent of the demographic data, comorbidities, and treatments.
Stress‐induced cognition among radiologic technologists in COVID‐19 quarantine centres in Palestine
Authors: Rimawi Omar , ALMasri Hussein
Published: March 2021

Background

The outbreak of COVID‐19 brought high mortality rate from the viral infection and caused a huge psychological stress for healthcare staff who work under great pressure during the pandemic.

Aims

The purpose of this study is to assess the level of stress‐induced cognition among radiologic technologists (RTs) in COVID‐19 quarantine centres in Palestine after the outbreak of COVID‐19.

Methods

Stress‐induced cognition was assessed using Stress‐induced Cognition Scale (SCS) questionnaire. The validity and stability of the measuring tool was verified. The sample consisted of 61 RTs who are working currently at various quarantine centres in Palestine.

Results

Cognition‐induced stress was higher than average. There was a statistically significant difference between RTs working directly with COVID‐19 patient compared with RTs working indirectly. Additionally, results show an increased level of stress for RTs having children compared with single or non‐parent RTs. Also, RTs who dealt with COVID‐19 patients for prolonged periods over a month had higher level of stress‐induced cognition. Other variables did not show significant differences among RTs.

Conclusion

It is recommended to provide psychological support for RTs who dealt and are currently involved in COVID‐19 quarantine centres to alleviate stress‐induced cognition.
Roost sites of chimney swift (Chaetura pelagica) form large‐scale spatial networks
Authors: le Roux Courtney E. , Nocera Joseph J.
Published: March 2021

Several biodiversity‐centered metrics exist to quantify the importance of landscape and habitat features for conservation efforts. However, for species whose habitat use is not quantified by these metrics, such as those in urban areas, we need a method to best identify features for targeted conservation efforts. We investigated the use of social network analysis (SNA) to identify and quantify these critical habitat features. We used SNA to identify network existence in chimney swift (Chaetura pelagica) roost usage, quantify the importance of each roost site, and evaluate the impact of the loss of key sites. We identified a network consisting of ten chimney swift roosts in southern Nova Scotia, Canada, and found that 76% of swifts used more than one roost throughout the breeding season. We also isolated three key (most connected) roost sites. We evaluated the effect of loss of these key sites on the network by using a Wilcoxon‐Pratt signed‐rank test and by analyzing the structure of the subsequent network. We found that connections between roosts and the structure of the network were significantly affected by the loss of these key sites. Our results show that SNA is a valuable tool that can identify key sites for targeted conservation efforts for species that may not be included in conservation efforts focused purely on biodiversity.
Who let the dogs out? Exploring the spatial ecology of free‐roaming domestic dogs in western Kenya
Authors: Muinde Patrick , Bettridge Judy M. , Sousa Filipe M. , Dürr Salome , Dohoo Ian R. , Berezowski John , Mutwiri Titus , Odinga Christian O. , Fèvre Eric M. , Falzon Laura C.
Published: March 2021

The spatial ecology of free‐roaming dogs determines their role in the transmission of zoonoses. This study describes the geographic range of and identifies sites frequently visited by free‐roaming domestic dogs in western Kenya.

Eight sites in Busia county, western Kenya, were selected. At each site, ten dog‐keeping households were recruited, a questionnaire was administered, and a GPS logger was fixed around the neck of one dog in each household. Loggers were programmed to capture the dog's position every minute, for five consecutive days. Individual summaries of GPS recordings were produced, and the daily distance traveled was calculated. 50% and 95% utilization distribution isopleths were produced, and the area within these isopleths was extracted to estimate the size of the core and extended Home Ranges (HRs), respectively. Linear regression analyses were performed to identify factors associated with the movement parameters. The centroid points of the 10, 50, and 90% isopleths were reproduced, and the corresponding sites identified on the ground.

Seventy‐three dogs were included in the final analyses. The median daily distance traveled was 13.5km, while the median core and extended HRs were 0.4 and 9.3 ha, respectively. Older dogs had a larger extended HR and traveled more daily, while the effect of sex on dog movement depended on their neutering status. Dogs spent most of their time at their household; other frequently visited sites included other household compounds, fields, and rubbish dumps. One of the centroids corresponded to a field located across the international Kenya–Uganda border, emphasizing the fluidity across the border in this ecosystem. Multiple dogs visited the same location, highlighting the heterogeneous contact networks between dogs, and between dogs and people.

The field data presented are of value both in understanding domestic dog ecology and resource utilization, and in contextualizing infectious and parasitic disease transmission models.