bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute and medium term results of balloon expandable stent placement in the transverse arch—a multicenter pediatric interventional cardiology early career society study
Authors: Shahanavaz Shabana , Aldoss Osamah , Carr Kaitlin , Gordon Brent , Seckeler Michael D. , Hiremath Gurumurthy , Seaman Cameron , Zablah Jenny , Morgan Gareth
Published: September 2020

Objectives and Background

Coarctation of the aorta represents 5–8% of all congenital heart disease. Although balloon expandable stents provide an established treatment option for native or recurrent coarctation, outcomes from transverse arch (TAO) stenting, including resolution of hypertension have not been well studied. This study aims to evaluate immediate and midterm results of TAO stenting in a multi‐center retrospective cohort.

Methods

TAO stenting was defined as stent placement traversing any head and neck vessel, with the primary intention of treating narrowing in the transverse aorta. Procedural details, complications and medications were assessed immediately post procedure, at 6 month follow‐up and at most recent follow‐up.

Results

Fifty‐seven subjects, 12 (21%) native, and 45 (79%) surgically repaired aortic arches, from seven centers were included. Median age was 14 years (4 days–42 years), median weight 54 kg (1.1–141 kg). After intervention, the median directly measured arch gradient decreased from 20 mmHg (0–57 mmHg) to 0 mmHg (0–23 mmHg) (p < .001). The narrowest arch diameter increased from 9 mm (1.4–16 mm) to 14 mm (2.9–25 mm) (p < .001), with a median increase of 4.9 mm (1.1–10.1 mm). One or more arch branches were covered by the stent in 55 patients (96%). There were no serious adverse events. Two patients warranted stent repositioning following migration during deployment. There were no late complications. There were 8 reinterventions, 7 planned, and 1 unplanned (6 catheterizations, 2 surgeries). Antihypertensive management was continued in 19 (40%) at a median follow‐up of 3.2 years (0.4–7.3 years).

Conclusions

TAO stenting can be useful in selected patients for resolution of stenosis with minimal complications. This subset of patients are likely to continue on antihypertensive medications despite resolution of stenosis.
Amplatzer left atrial appendage closure: Single versus combined procedures
Authors: Kleinecke Caroline , Buffle Eric , Link Juergen , Häner Jonas , Sedaghat Alexander , Galea Roberto , Streit Samuel R. , Windecker Stephan , Meier Bernhard , Gloekler Steffen
Published: September 2020

Objectives

This study compares procedural and late clinical outcomes of left atrial appendage closure (LAAC) with Amplatzer devices as a single versus a combined procedure with other structural or coronary interventions.

Background

Multiple cardiac conditions are frequent among elderly patients and invite simultaneous treatment to ensure a favorable patient outcomes.

Methods

559 consecutive patients (73.3 ± 11.1 years) underwent LAAC with Amplatzer devices at two centres (Bern and Zurich university hospitals, Switzerland) either as a single procedure or combined with other interventions. The primary safety endpoint was a composite of major peri‐procedural complications and major bleeding at follow‐up, the primary efficacy endpoint included stroke, systemic embolism, and cardiovascular/unexplained death. All event rates are reported per 100 patient‐years.

Results

In 263 single and 296 combined procedures with percutaneous coronary interventions (47.6%), closure of an atrial septal defect (8.4%) or a patent foramen ovale (36.5%), transcatheter aortic valve implantation (10.1%), mitral clipping (4.1%), atrial fibrillation ablation (8.8%), or another procedure (3.0%) were analyzed. Device success (96.6% [single] vs. 99.0% [combined], p = .08) did not differ between the groups. After a mean follow‐up of 2.6 ± 1.5 vs. 2.5 ± 1.5 years and a total of 1,422 patient‐years, the primary efficacy (40/677, 5.9% [single] vs. 37/745, 5.0% [combined]; HR, 1.2, 95% CI, 0.8–1.9, p = .44), as well as the primary safety endpoint (25/677, 3.7% vs 28/745, 3.8%; HR, 1.0, 95% CI, 0.6–1.8, p = .89) were comparable.

Conclusions

LAAC with Amplatzer devices combined with structural, coronary, and electrophysiological procedures offers procedural feasibility and safety, as well as long‐term efficacy.
Long‐term follow‐up of insulin autoimmune syndrome in an elderly patient
Authors: Yoshino Hiroshi , Kawakami Kyoko , Kohriyama Kenji , Yoshino Gen , Matsunaga Shinji , Takechi Hajime
Published: September 2020

An 84‐year‐old man was admitted to our hospital. His blood glucose level was 20 mg/dL. Since laboratory tests showed high titers of insulin antibodies, insulin autoimmune syndrome (IAS) was diagnosed. In　order to avoid hypoglycemia, steroids can be effective in the long‐term management of IAS in elderly patients.
Idiopathic hypereosinophilic syndrome: A rare diagnosis in children
Authors: Pallesen Kristine Appel Uldall , Herlin Troels , Holm Mette , Høst Christian , Christiansen Mette , Ramsing Mette , Rasmussen Mads Kirchheiner , Sommerlund Mette
Published: September 2020

Idiopathic hypereosinophilic syndrome (IHES) is one of numerous hypereosinophilic syndromes. The incidence of IHES among children is unknown, but it is considered a rare disease. We report a pediatric case of IHES and the challenges to finding an effective treatment. The patient described here was responsive to prednisolone and thalidomide.
A rare skin infection in atopic dermatitis: A case report
Authors: Malara Giovanna , Trifirò Caterina , Bartolotta Annunziata , Conte Marco , Denisi Pietro
Published: September 2020

Atopic dermatitis is associated with a susceptibility to infection usually by Staphylococcus spp due to a decrease of AMPs and Th2 cytokines (eg, IL‐17). We reported a rare E. faecalis skin contamination in AD patients due to a frequent contact with excrement.
Treatment of cytokine storm syndrome with IL‐1 receptor antagonist anakinra in a patient with ARDS caused by COVID‐19 infection: A case report
Authors: Kaps Leonard , Labenz Christian , Grimm Daniel , Schwarting Andreas , Galle Peter R. , Schreiner Oliver
Published: September 2020

The biological anakinra appears promising to halt cytokine storm syndrome seen in severe courses of COVID‐19. However, immunosuppression with anakinra may facilitate sepsis, necessitating continuous screening for bacterial superinfections.
Light‐chain amyloid myopathy isolated to skeletal muscles: A case report
Authors: Matsukawa Toshihiro , Eguchi Katsuki , Nishino Ichizo , Okada Kohei , Oshimi Kazuo , Miyagishima Takuto
Published: September 2020

Isolated amyloidosis, especially of amyloid light‐chain type, is an infrequent disease. Systemic chemotherapy for light‐chain amyloidosis isolated to skeletal muscles plays a key role to reduce clonal plasma cells producing aberrant immunoglobulin.
Tension pneumothorax in a patient with granulomatosis
Authors: Ahmadinejad Mojtaba , Afrasiabi Saman
Published: September 2020

A woman with a clinical presentations of granulomatosis with polyangiitis (GPA) has been presented. Tension pneumothorax has been rarely reported; however, it is a life‐threatening condition. Surgical intervention may be required in GPA patients who do not respond to chest tube insertion. Timely management can reduce the complication and mortality.
Carboxyl Methyltransferases: Natural Functions and Potential Applications in Industrial Biotechnology
Authors: Ward Lucy C. , McCue Hannah V. , Carnell Andrew J.
Published: September 2020

The use of methyltransferases (MTs) in industrial biotechnology to replace toxic alkylating agents is of increasing interest. Carboxyl MTs (CMTs) are a subgroup of MTs that methylate the hydroxyl oxygen of carboxylic acids. Research initially focussed on their natural functions in protein regulation and production of volatile methyl esters in plants. In this review we highlight this potentially valuable group of enzymes that show promise for formation of a wide range of structurally diverse methyl esters from the parent acids under aqueous conditions. CMTs have been used to generate intermediates for biofuels, bioplastics and pharmaceuticals. These biocatalysts could also be integrated into cascades with other enzymes such as acyltransferases that function under aqueous conditions. Recent approaches for regenerating the required cofactor S‐adenosylmethionine (SAM) are discussed including in vitro recycling, improvement in in vivo production and the use of more stable analogues. Advances in these areas will further improve the potential to use carboxyl MTs in industrial biotechnology.
Influence of Particle Size on the Performance of Polysulfone Magnetic Membranes for O2/N2 Separation
Authors: Raveshiyan Saba , Karimi-Sabet Javad , Hosseini Seyed Saeid
Published: September 2020

Magnetic mixed‐matrix membranes (MMMs) are fabricated using polysulfone (PSf) and iron oxide (Fe) for O2/N2 separation. The effects of Fe nanoparticle size and content on the performance of the membranes are investigated using a novel gas permeation unit in the presence of various magnetic fields. The results indicate that the O2 permeation is improved by adding Fe nanoparticles into the PSf matrix regardless of the particle size. Furthermore, the selectivity of PSf and PSf‐Fe membranes is considerably enhanced by applying a magnetic field during the permeation experiments. The O2 permeability and O2/N2 selectivity of PSf‐Fe50 MMMs in the presence of a magnetic field are higher than those of neat PSf membranes.
Designing Solid‐State Electrolytes through the Structural Modification of a High‐Performing Ionic Liquid
Authors: Al‐Masri Danah , Yunis Ruhamah , Hollenkamp Anthony F. , Pringle Jennifer M.
Published: September 2020

Solid‐state electrolytes can address many of the challenges associated with lithium metal batteries, as they can suppress the reactivity of the lithium metal and reduce the growth of dendrites, which is a main cause of device failure. However, achieving sufficient target ion transport through solid electrolytes remains a challenge. Here we report the structural modification of a high‐performing ionic liquid to form a quasi‐solid state electrolyte. Thus, the organic ionic plastic crystal N‐isopropyl‐N‐methylpyrrolidinium bis(fluorosulfonyl)imide, [C(i3)mpyr][FSI], has been synthesized and, when mixed with lithium salt, is shown to have a similar lithium‐ion transference number as the analogous [C3mpyr][FSI] ionic‐liquid‐based electrolyte. Furthermore, high ionic conductivity and efficient lithium cycling are demonstrated for two quasi‐solid‐state electrolytes, one with the very high lithium salt content of 90 mol % LiFSI.
Numerical Deconvolution of Surface Interrogation Scanning Electrochemical Microscopy Experiments on Platinum During Hydrogen Evolution
Authors: Jantz Dylan T. , Seuferling Tess E. , Leonard Kevin C.
Published: September 2020

It is experimentally challenging to deconvolute the potential‐dependent adsorption of the different intermediates that occur during the hydrogen evolution reaction (HER) in alkaline media. This difficulty has limited our understanding regarding why the HER kinetics are more sluggish in alkaline media compared to acidic media. Herein, we utilized the surface interrogation mode of scanning electrochemical microscopy (SI‐SECM) to investigate the surface adsorbed species that form during the HER in alkaline media on polycrystalline platinum, Pt(poly). To deconvolute the different adsorbed intermediates, we developed a detailed COMSOL‐based kinetic model to rapidly simulate the SI‐SECM titration reactions under our experimental conditions. Utilization of this rapid‐kinetic model overcomes the limitation of SI‐SECM not having the ability to simultaneously resolve multiple surface adsorbed intermediates. We demonstrate that these numerical simulations can separate the potential dependant formation of the underpotential deposition of hydrogen (H(UPD)) from the overpotential deposition (H(OPD)) of hydrogen. In addition, our simulations show that a spectator species may also exist on the surface during HER potentials. Our simulations also show that at full H2‐producing potentials, the surface of Pt(poly) is fully saturated with intermediates. Comparison between the potential‐dependent adsorption of H(OPD) and Tafel analysis reveal that the Heyrovsky step is likely rate‐determining in alkaline media. However, in alkaline media the Heyrovsky step transitions from first‐order in H(OPD) at low H(OPD) coverage to zero‐order at high H(OPD) coverage, due to surface saturation of adsorbed intermediates. Tafel analysis in acidic media shows that the Heyrovsky step is likely rate‐determining, but remains first‐order in Had over a larger potential range. These fundamental insights reveal that a sluggish Heyrovsky step is a major contributor to the attenuated kinetics of the HER in alkaline media.
The Role of Fluorine in Glycomimetic Drug Design
Authors: Hevey Rachel
Published: September 2020

Glycans are well established to play important roles at various stages of infection and disease, and ways to modulate these interactions have been sought as novel therapies. The use of native glycan structures has met with limited success, which can be attributed to their characteristic high polarity (e.g., low binding affinities) and inherently poor pharmacokinetic properties (e.g., short drug–target residence times, rapid renal excretion), leading to the development of ′glycomimetics′. Fluorinated drugs have become increasingly common over recent decades, with fluorinated glycomimetics offering some unique advantages. Deoxyfluorination maintains certain electrostatic interactions, while concomitantly reducing net polarity through ′polar hydrophobicity′, improving residence times and binding affinities. Fluorination destabilizes the oxocarbenium transition state associated with metabolic degradation, and can restore exo‐ and endo‐anomeric effects in C‐glycosides and carbasugars. Lastly, it has shown great utility in radiotracer development and enhancement of antigenicity in glycan‐based vaccines. Owing to synthetic challenges, fluorinated glycomimetics have been somewhat underutilized to date, but methodological improvements will advance their use in glycomimetic drugs.
Redox‐Mediated Alcohol Oxidation Coupled to Hydrogen Gas Formation in a Dye‐Sensitized Photosynthesis Cell
Authors: Bruggeman Didjay F. , Bakker Tijmen M. A. , Mathew Simon , Reek Joost N. H.
Published: September 2020

This work reports a dye‐sensitized photoelectrochemical cell (DSPEC) that couples redox‐mediated light‐driven oxidative organic transformations to reductive hydrogen (H2) formation. The DSPEC photoanode consists of a mesoporous anatase TiO2 film on FTO (fluorine‐doped tin oxide), sensitized with the thienopyrroledione‐based dye AP11, while H2 was formed at a FTO‐Pt cathode. Irradiation of the dye‐sensitized photoanode transforms 2,2,6,6‐tetramethylpiperidine 1‐oxyl (TEMPO) to the oxidized TEMPO (TEMPO+), which acts as a chemical oxidant for the conversion of benzyl alcohol. The TEMPO0/+ couple, previously used as redox mediator in DSSC, mediates efficient electron transfer from the organic substrate to the photo‐oxidized dye. A DSPEC photoreactor was designed that allows in situ monitoring the reaction progress by infrared spectroscopy and gas chromatography. Sustained light‐driven oxidation of benzyl alcohol to benzaldehyde within the DSPEC photoreactor, using of TEMPO as mediator, demonstrated the efficiency of the device, with a photocurrent of 0.4 mA cm−2, approaching quantitative Faradaic efficiency and exhibiting excellent device stability.
Divergent Asymmetric Reactions of ortho‐Quinone Methides with α‐Thiocyanato Indanones for the Synthesis of Spiro‐ and Fused‐Indanones
Authors: Liu Xianghui , Wang Kai , Liu Yan , Li Can
Published: September 2020

Reported in this work is a water triggered chemo‐divergent enantioselective spiro‐annulation and cascade reaction of ortho‐quinone methides (o‐QMs) with α‐thiocyanato indanones catalyzed by a chiral organic base. In the case of spiro‐annulation, the use of trace amount of water as additive is critical to achieve high enantioselectivity (up to 96 % ee). We found that a cascade reaction was enabled by just tuning the ratio of water in solvent. Accordingly, two new highly efficient asymmetric reactions for the divergent synthesis of spiro‐ and fused‐indanone scaffolds with excellent enantioselectivities (up to 99 % ee) were developed. Mechanistic investigations suggest that interfacial hydrogen bonding may play an important role in achieving the switchable reaction pathways.
Clar Goblet and Aromaticity Driven Multiradical Nanographenes
Authors: Gil‐Guerrero Sara , Melle‐Franco Manuel , Peña‐Gallego Ángeles , Mandado Marcos
Published: September 2020

The Clar Goblet, the first radical bowtie nanographene proposed by Erich Clar nearly 50 years ago, was recently synthesized. Bowtie nanographenes present quasi‐degenerate magnetic ground states, which make them so elusive as unique. A thorough analysis is presented of the spin‐state energetics of Clar Goblet and bowtie nanographenes by a battery of existing and novel ab initio procedures ranging from density functional theory to complete active space Hamiltonians. With this, it was proven that π radicals of bowtie nanographenes sit on BP (Benzo[cd]Pyrene) moieties driven by their local aromaticity, a purely chemical concept, which confers global stability to the whole structure. Besides, a novel Pauli energy densities analysis provided a visual intuitive explanation for this preference. These findings allow envisioning that analogous bowtie nanographenes with arbitrary polyradical character are not only feasible at the molecular scale but will share Clar Goblet's peculiar properties.
Regioselective Formation of Substituted Indoles: Formal Synthesis of Lysergic Acid
Authors: Points Gary L. , Stout Kenneth T. , Beaudry Christopher M.
Published: September 2020

A Diels–Alder reaction‐based strategy for the synthesis of indoles and related heterocycles is reported. An intramolecular cycloaddition of alkyne‐tethered 3‐aminopyrones gives 4‐substituted indolines in good yield and with complete regioselectivity. Additional substitution is readily tolerated in the transformation, allowing synthesis of complex and non‐canonical substitution patterns. Oxidative conditions give the corresponding indoles. The strategy also allows the synthesis of carbazoles. The method was showcased in a formal synthesis of lysergic acid.
Transient Optimization of Coproduction Systems for Steel and Value‐Added Chemicals
Authors: van Beek Mathias , Sadlowski Matthias
Published: September 2020

A mixed‐integer linear programming model for methanol production from steelmaking byproduct gases is presented, considering dynamic constraints of process units. Renewable energy is used to produce hydrogen for the process via electrolysis. A case study incorporates dynamic market prices and the CO2 footprint of the electric power consumption, revealing a CO2 saving potential of 18.5 % for the scenarios and configurations studied. The results indicate that upgrading the model to a design optimization in the future will increase savings.
Wiederbefeuchtung bei der Pressfiltration
Authors: Mazzi Fabio , Krammer Gernot
Published: September 2020

Bei der Pressfiltration kann es neben einer plastischen Verformung des Kuchens auch zu einer Volumenvergrößerung des Kuchens kommen, wenn die mechanischen Kräfte reduziert werden, wie Versuche mit einer wässrigen Kohlesuspension zeigen. Ist der Kuchen während dieses Vorgangs mit einem Flüssigkeitsfilm in Kontakt, tritt eine Wiederbefeuchtung des Kuchens ein und der Trockengehalt des Kuchens sinkt. Wenn ein konsequentes Abführen der Flüssigkeit gelingt, kann der Trockengehalt signifikant gesteigert mit einem niedrigeren Pressdruck das Auslangen gefunden werden.
Response surface modelling of CO2 capture by ammonia aqueous solution in a microchannel
Authors: Asgarifard Pourya , Rahimi Masoud , Tafreshi Navid
Published: September 2020

Post‐combustion CO2 capture is one strategy of greenhouse gases mitigation. Ammonia is a useful option as CO2 absorbent and an alternative to conventional amine‐based solutions. This study deals with CO2 capture by ammonia aqueous solution in a co‐current two‐phase flow by utilizing a T‐shaped microchannel. Three parameters of temperature, gas flow rate, and ammonia concentration were considered as the main parameters affecting the CO2 capture efficiency. A response surface methodology based on central composite design (CCD) was used to model the CO2 capture efficiency as output in terms of the aforementioned input variables. CCD suggested a quadratic model to fit the experimental data. The model validation was implemented by ANOVA. All statistic tools including correlation coefficient, P‐value, and F‐value of the model, and P‐value of lack‐of‐fit confirmed that the prediction model was significant. It was deduced from F‐values that the importance of the input variables followed the sequence of ammonia concentration > gas flow rate > temperature. Ammonia concentration was the most effective input variable because there was a direct correlation between ammonia concentration and the number of absorption sites in the liquid phase. Numerical optimization predicted the best output of 96.48% CO2 capture under the following optimum conditions: temperature of 20.00°C, gas flow rate of 110.59 mL/min, and ammonia concentration of 0.1382 mL/mL (13.82 vol%). The average CO2 capture of 95.42% obtained at the input conditions indicates the accuracy of the prediction model.
CFD simulation of solids residence time distribution for scaling up gas‐solid bubbling fluidized bed reactors based on the modified structure‐based drag model
Authors: Zhao Yunlong , Zou Zheng , Wang Junwu , Li Hongzhong , Zhu Qingshan
Published: September 2020

Solids residence time distribution (RTD), which reflects the degree of solids mixing in bubbling fluidized bed (BFB), has become an essential parameter for the evaluation of reactor performances. In this paper, a modified structure‐based drag model was established to investigate the effect of the bed size and the correlation of bubble dimension on the gas‐solids hydrodynamics and solids RTD in three different scales of BFB. The result obtained from the modified structure‐based drag model shows better agreement with the experimental values and it can be used to predict the RTD properly. The deviation of flow field will cause a large difference in the RTD prediction. An accurate flow field is a prerequisite for calculating the RTD. For the cases of Geldart B particles, the Darton correlation is the best choice for low gas velocities. When scaling up a BFB, the RTD calculated by the modified structure‐based drag model is reduced in comparison with the experimental value, which is related to the increase of the bed size and the excessive estimation of the bubble size. On the other hand, the lack of consideration for the friction on both front and back walls in 2D simulation may lead to the over‐prediction of particle velocity and result in the deviation between calculated and experimental RTD value.
Improvement of CO2 absorption by Fe3O4/water nanofluid falling liquid film in presence of the magnetic field
Authors: Pahlevaninezhad Maedeh , Etesami Nasrin , Nasr Esfahany Mohsen
Published: September 2020

Carbon dioxide is considered as the main greenhouse gas responsible for climate change. Absorption of CO2 by liquid phase has gained attention as a means of mitigating environmental challenges. In this study, the effect of Fe3O4 nanoparticles on the CO2‐water mass transfer coefficient was experimentally evaluated in the presence and absence of a magnetic field. The absorption experiments were carried out in a falling liquid film absorber system in laminar and turbulent flow regimes. Fe3O4/water nanofluid was used in 0.001‐0.05 vol% concentrations. The results show that adding Fe3O4 nanoparticles to water increases the mass transfer coefficient (MTC), and that it increases with an increase in nanofluid concentration. For a concentration of 0.05 vol% nanofluid, the MTC was improved 111% and 13.7% in the turbulent and laminar flow regimes, respectively. The mass transfer coefficient of CO2 in water and effective mass transfer coefficient in nanofluid were increased up to 10% and 29% in the presence of a parallel alternative magnetic field, respectively.
Synthesis of single‐phase and controlled monodisperse magnetite Fe3O4 nanoparticles
Authors: Gandon Arnaud , Nguyen Chinh Chien , Kaliaguine Serge , Do Trong On
Published: September 2020

We report a simple solvothermal method for the synthesis of monodisperse magnetite nanoparticles with a controlled particle size within the range of 40 to 200 nm from available and inexpensive single iron precursor (FeCl3) and, as co‐capping agents, sodium acetate and ethylene diamine. The particle size can be easily controlled by the reaction time of synthesis. Transmission electron microscopy, x‐ray diffraction, Fourier transform infrared spectroscopy, and x‐ray photoelectron spectroscopy techniques were used to investigate the obtained particles. The results revealed that the resulting iron oxide particles exhibit a single magnetite Fe3O4 phase and high stability in air even for four months. The high air stability of these magnetite could be due to the surfactant capped on the particle surface. This method of synthesis has some advantages including simplicity, high product quality, and acceptable reproducibility. Therefore, the magnetite particles can be used for different applications such as in catalysis and drug delivery.
A practical model for the supply chain growth optimization for automotive fuels in Mexico
Authors: García Jolly Rafael , Martín del Campo Cecilia
Published: September 2020

Profitability and energy efficiency depend on optimal operation of a supply chain network for automotive fuels in Mexico, even for clean energy expectations. This paper shows how decision‐making for fuels‐distribution network growth in Mexico points in the same direction, while the practical small optimization model, introduced in this paper, replaces a detailed model thereby offering great advantages to the analysts. The paper also describes the relevant strategies that were applied to ensure equivalences between the two models representing a supply chain. The model simplification not only reduces its size and computer time for execution but allows for the most relevant time reduction associated with preparing the data input to feed into the model, as well as in analyzing the results. Some distribution network growth options were evaluated by using both models with equivalent objective functions. Small model results give enough information for decision‐making support. The use of new facilities and economic benefits are similar to those obtained with the complex model. The main issues to take care of are bottleneck identification and commodities differentiation. If a binding constraint is removed in the small model, similar results are seen in the complex model when a specific bottleneck is improved. This is the first time that a practical model is used to evaluate multiple scenarios of the complex automotive fuel distribution network in Mexico.
Advances in Single‐Atom Nanozymes Research†
Authors: Jiang Bing , Liang Minmin
Published: September 2020

Nanozymes with intrinsic enzyme‐like properties have attracted significant interest owing to their capability to address the limitations of traditional enzymes such as fragility, high cost and difficult mass production. However, the currently reported nanozymes are generally less active than natural enzymes. In recent years, with the rapid development of nanoscience and nanotechnology, single‐atom nanozymes (SAzymes) with well‐defined electronic and geometric structures have shown a promise to serve as direct surrogates of traditional enzymes by mimicking the highly evolved catalytic center of natural enzymes. In this review, we will introduce the enzymatic characteristics and recent advances of SAzymes, and summarize their significant applications from in vitro detection to in vivo monitoring and therapy.
Interfacial Degradation and Optimization of Li‐rich Cathode Materials†
Authors: Su Yuefeng , Zhao Jiayu , Chen Lai , Li Ning , Lu Yun , Dong Jinyang , Fang Youyou , Chen Shi , Wu Feng
Published: September 2020

High‐energy and safe lithium ion batteries (LIBs) are in increasing need as the rapid development of electronic devices, electric vehicles, as well as energy storage station. Li‐rich oxides have attracted a lot of attention due to their high capacity and low cost as cathode material for LIBs. However, they still suffer from the vulnerable cathode/ electrolyte interface, which presents the huge challenges of surface degradation and gas release, particularly at high state of charge. Some issues of Li‐rich cathode materials, such as moderate cycle stability and voltage decay, are in tight connection with electrode‐electrolyte interfacial side reactions. Research in the area of interfacial degradation mechanism and optimization strategies is of great significance as for Li‐rich cathode, and extensive efforts have been poured. This review aims to understand the degradation mechanism of Li‐rich cathode materials, and summarize the corresponding valuable and effective optimization strategies. Based on these considerations, we also have discussed the remaining challenges and the future research direction.
Catalytic Asymmetric Mannich‐Type Reaction Enabled by Efficient Dienolization of α,β‐Unsaturated Pyrazoleamides†
Authors: Zhang Hai‐Jun , Zhong Feng , Xie Yan‐Cheng , Yin Liang
Published: September 2020

Main observation and conclusion

(E)‐α,β‐Unsaturated pyrazoleamides undergo facile dienolization to furnish copper(I)‐(1Z,3Z)‐dienolates as the major in the presence of a copper(I)‐(R)‐DTBM‐SEGPHOS catalyst and Et3N, which react with aldimines to afford syn‐vinylogous products as the major diastereoisomers in high regio‐ and enantioselectivities. In some cases, the diastereoselectivity is low, possibly due to the low ratio of copper(I)‐(1Z,3Z)‐dienolates to copper(I)‐(1Z,3E)‐dienolates. (Z)‐Allylcopper(I) species is proposed as effective intermediates, which may form an equilibrium with copper(I)‐(1Z,3Z)‐dienolates. Interestingly, the present methodology is a nice complement to our previous report, in which (E)‐β,γ‐unsaturated pyrazoleamides were employed as the prenucleophiles in the copper(I)‐catalyzed asymmetric vinylogous Mannich‐Type reaction and anti‐vinylogous products were obtained. In the previous reaction, copper(I)‐ (1Z,3E)‐dienolates were generated through α‐deprotonation, which might form an equilibrium with (E)‐allylcopper(I) species. Therefore, it is realized in the presence of a copper(I) catalyst that (E)‐α,β‐unsaturated pyrazoleamides lead to syn‐products and (E)‐β,γ‐unsaturated pyrazoleamides lead to anti‐products. Finally, by use of (E)‐β,γ‐unsaturated pyrazoleamide, (E)‐α,β‐unsaturated pyrazoleamide, (R)‐DTBM‐SEGPHOS, and (S)‐DTBM‐SEGPHOS, the stereodivergent synthesis of all four stereoisomers is successfully carried out. Then by following a three‐step reaction sequence, all four stereoisomers of N‐Boc‐2‐Ph‐3‐Me‐piperidine are synthesized in good yields, which potentially serve as common structure units in pharmaceutically active compounds.
Palladium‐Catalyzed Tandem Carbonylative Aza‐Wacker‐Type Cyclization of Nucleophile Tethered Alkene to Access Fused N‐Heterocycles
Authors: Shi Lijun , Wen Mingshan , Li Fuwei
Published: September 2020

Main observation and conclusion

Although tandem reactions offer rapid access to structurally complex molecules in one‐pot reaction, the selectivity issue needs to be addressed particularly when incompatible step reactions are involved. Herein, we report the selective synthesis of fused N‐heterocycles from nucleophile‐tethered alkenylamide and carbon monoxide via palladium (Pd)‐catalyzed tandem carbonylative aza‐Wacker‐type cyclization. The electron‐deficient nature of amide N—H and the intramolecular coordination of Pd with alkene accelerate the aminopalladation and effectively prevent the side oxidative carbonylation of diamine moiety to form urea. It is also found that the reported acyl Pd chloride intermediate may not be involved in this tandem cyclization. This work not only provides an efficient synthetic route to fused 1,4‐diazepanones and 1,4‐diazepanes but also inspires further development of tandem reactions for the diverse synthesis of heterocycles.
Enantioselective Arylcyanation of Styrenes viaCopper‐Catalyzed Radical Relay†
Authors: Zhuang Weiwen , Chen Pinhong , Liu Guosheng
Published: September 2020

The first copper‐catalyzed enantioselective arylcyanation of styrenes has been developed using readily available anilines as aryl radical precursors under mild conditions, which enables easy access to chiral 2,3‐diaryl propionitriles with moderate to good enantioselectivities. This operationally straightforward reaction exhibits broad substrate scope and functional group tolerance. Notably, this method has been applied to the synthesis of chiral AIEgen as well as estrogen receptor‐β agonist (R)‐diarylpropionitrile (DPN).
Structure‐Activity Studies of Truncated Latrunculin Analogues with Antimalarial Activity
Authors: Varghese Swapna , Rahmani Raphaël , Drew Damien R. , Beeson James G. , Baum Jake , Smith Brian J. , Baell Jonathan B.
Published: September 2020

Malarial parasites employ actin dynamics for motility, and any disruption to these dynamics renders the parasites unable to effectively establish infection. Therefore, actin presents a potential target for malarial drug discovery, and naturally occurring actin inhibitors such as latrunculins are a promising starting point. However, the limited availability of the natural product and the laborious route for synthesis of latrunculins have hindered their potential development as drug candidates. In this regard, we recently described novel truncated latrunculins, with superior actin binding potency and selectivity towards P. falciparum actin than the canonical latrunculin B. In this paper, we further explore the truncated latrunculin core to summarize the SAR for inhibition of malaria motility. This study helps further understand the binding pattern of these analogues in order to develop them as drug candidates for malaria.
sp3‐Rich Glycyrrhetinic Acid Analogues Using Late‐Stage Functionalization as Potential Breast Tumor Regressing Agents
Authors: Kallepu Shivakrishna , Neeli Praveen Kumar , Mallappa Sreevidya , Nagendla Narendra Kumar , Reddy Mudiam Mohana Krishna , Mainkar Prathama S. , Kotamraju Srigiridhar , Chandrasekhar Srivari
Published: September 2020

Late‐stage functionalization (LSF) aids drug discovery efforts by introducing functional groups onto C−H bonds on pre‐existing skeletons. We adopted the LSF strategy to synthesize analogues of the abundantly available triterpenoid, glycyrrhetinic acid (GA), by introducing aryl groups in the A‐ring, expanding the A‐ring and selectively activating one methyl group of the gem‐dimethyl groups. Intriguingly, two compounds were found to preferentially accumulate in the mitochondrial compartment of MDA‐MB‐231 breast cancer cells, to cause depolarization of mitochondrial membrane potential and to induce antiproliferative and anti‐invasive effects through enhanced mitochondrial superoxide production with parallel depletion of GSH levels. Furthermore, intraperitoneal administration of these two compounds, in comparison with GA, greatly regressed breast tumor growth and metastasis in a SCID mouse model bearing labeled MDA‐MB‐231 cells.
Efficacy and safety of immune checkpoint blockade in self‐identified Black patients with advanced non–small cell lung cancer
Authors: Nazha Bassel , Goyal Subir , Chen Zhengjia , Engelhart Anne , Carlisle Jennifer Wilkinson , Beardslee Tyler J. , Gill Harpaul , Odikadze Levani , Liu Yuan , Mishra Manoj K. , Ramalingam Suresh S. , Owonikoko Taofeek Kunle
Published: September 2020

Background

To the authors' knowledge, race‐based differences in efficacy for the treatment of patients with advanced non–small cell lung cancer (NSCLC) have not been studied to date due to the underrepresentation of patients of minority backgrounds in pivotal trials. In the current study, the authors examined real‐world differences in outcome in a diverse patient population.

Methods

The authors retrospectively analyzed the clinical outcomes of patients with advanced NSCLC who were treated with single‐agent immune checkpoint blockade (ICB) between 2013 and July 2018 at Winship Cancer Institute of Emory University in Atlanta, Georgia. Primary efficacy comparison between Black patients and White patients was performed using bivariate and multivariate analyses for overall survival (OS) and progression‐free survival (PFS).

Results

Data from 257 patients were analyzed. The median age of the patients was 69 years; 50.6% of the patients were female, 63.4% were White, 29.5% were Black, and 7.1% of the patients were of “other” race. ICB was the first‐line treatment in 51 patients (19.9%), the second‐line treatment in 161 patients (62.6%), and the third‐line treatment in 33 patients (12.9%). The most commonly used agents were nivolumab (49.0%), pembrolizumab (25.2%), and atezolizumab (21.3%). No differences with regard to OS (P = .839) and PFS (P = .235) were noted between Black and White patients. The sample overall response rate was 20.6% (15.2% in Black patients and 23.1% in White patients). No differences with regard to OS (P = .081) and PFS (P = .176) were observed between female and male patients. The rate of immune‐related adverse events was found to be similar in Black and White patients (20.0% vs 29.9%; P = .148). On multivariate analysis, race was not found to be significantly associated with OS or PFS.

Conclusions

Real‐world analysis of the authors' institutional experience demonstrated similar efficacy and tolerability of ICB in Black versus White patients with advanced NSCLC. Larger multi‐institutional studies including other US minority populations would make the findings of the current study more generalizable.
Determining the significance of psammoma bodies in pelvic washings: A 10‐year retrospective review
Authors: Sun Tong , Pitman Martha B. , Torous Vanda F.
Published: September 2020

Background

Pelvic washing specimens are relatively common and are submitted for patients undergoing gynecologic surgery to evaluate them for metastatic or occult disease. Psammoma bodies are a relatively uncommon finding in these specimens. To date, large‐scale studies of their cytologic‐histologic correlates and thus clinical significance have been limited.

Methods

A 10‐year retrospective search for all pelvic washing specimens was performed, and all cases were reviewed for the presence of psammoma bodies. The findings for the corresponding surgical pathology specimens were then catalogued.

Results

Psammoma bodies were present in 138 cases (3.6% of 3840 total pelvic washings). More than half of the cases (n = 73 [53%]) were associated with benign processes, including mesothelial hyperplasia (n = 44), endosalpingiosis (n = 11), endometriosis (n = 11), and ovarian cystadenoma/cystadenofibroma (n = 7). Nineteen cases (14%) were associated with serous borderline tumors. Malignancies were noted in a third of the cases (n = 46 [33%]) and were most frequently low‐grade serous adenocarcinomas (n = 15), high‐grade serous adenocarcinomas (n = 11), or endometrioid endometrial carcinomas (n = 8). Patients found to have benign processes (median age, 50 years) or borderline disease (median age, 56 years) were significantly younger than patients with malignancies (median age, 65 years; P < .0001). In addition, the correlation of cytologic interpretation categories with concurrent histopathologic findings showed that cytologic analysis was highly sensitive and specific in determining the nature of underlying processes.

Conclusions

The majority of psammoma bodies noted in pelvic washings were associated with benign processes or borderline tumors, with approximately a third of the cases associated with malignancies. Psammoma bodies in pelvic washings from younger patients were significantly more likely to be associated with benign processes or borderline tumors.
Rivalry between Regium and Hydrogen Bonds Established within Diatomic Coinage Molecules and Lewis Acids/Bases
Authors: Sánchez‐Sanz Goar , Trujillo Cristina , Alkorta Ibon , Elguero José
Published: September 2020

A theoretical study of the complexes formed by Ag2and Cu2with different molecules, XH (FH, ClH, OH2, SH2, HCN, HNC, HCCH, NH3and PH3) that can act as hydrogen‐bond donors (Lewis acids) or regium‐bond acceptors (Lewis bases) was carried out at the CCSD(T)/CBS computational level. The heteronuclear diatomic coinage molecules (AuAg, AuCu, and AgCu) have also been considered. With the exception of some of the hydrogen‐bonded complexes with FH, the regium‐bonded binary complexes are more stable. The AuAg and AuCu molecules show large dipole moments that weaken the regium bond (RB) with Au and favour those through the Ag and Cu atoms, respectively.
Whole‐Brain Image Analysis and Anatomical Atlas 3D Generation Using MagellanMapper
Authors: Young David M. , Duhn Clif , Gilson Michael , Nojima Mai , Yuruk Deniz , Kumar Aparna , Yu Weimiao , Sanders Stephan J.
Published: September 2020

MagellanMapper is a software suite designed for visual inspection and end‐to‐end automated processing of large‐volume, 3D brain imaging datasets in a memory‐efficient manner. The rapidly growing number of large‐volume, high‐resolution datasets necessitates visualization of raw data at both macro‐ and microscopic levels to assess the quality of data, as well as automated processing to quantify data in an unbiased manner for comparison across a large number of samples. To facilitate these analyses, MagellanMapper provides both a graphical user interface for manual inspection and a command‐line interface for automated image processing. At the macroscopic level, the graphical interface allows researchers to view full volumetric images simultaneously in each dimension and to annotate anatomical label placements. At the microscopic level, researchers can inspect regions of interest at high resolution to build ground truth data of cellular locations such as nuclei positions. Using the command‐line interface, researchers can automate cell detection across volumetric images, refine anatomical atlas labels to fit underlying histology, register these atlases to sample images, and perform statistical analyses by anatomical region. MagellanMapper leverages established open‐source computer vision libraries and is itself open source and freely available for download and extension. © 2020 Wiley Periodicals LLC.

Basic Protocol 1: MagellanMapper installation

Alternate Protocol: Alternative methods for MagellanMapper installation

Basic Protocol 2: Import image files into MagellanMapper

Basic Protocol 3: Region of interest visualization and annotation

Basic Protocol 4: Explore an atlas along all three dimensions and register to a sample brain

Basic Protocol 5: Automated 3D anatomical atlas construction

Basic Protocol 6: Whole‐tissue cell detection and quantification by anatomical label

Support Protocol: Import a tiled microscopy image in proprietary format into MagellanMapper
Distress tolerance and special alcohol metacognitions behave differently in the association of negative affect with alcohol‐related patterns in men with problematic alcohol use in the abstinence phase
Authors: Khosravani Vahid , Sharifi Bastan Farangis , Kolubinski Daniel C. , Amirinezhad Ali , Ghorbani Fatemeh
Published: September 2020

Negative affect may be related to alcohol‐related patterns (e.g., craving and problematic alcohol use). Distress intolerance and positive and negative alcohol‐related metacognitions may be underlying mechanisms in this link. This study aimed to evaluate the effect of negative affect including depressive, anxious, and stress symptoms on alcohol craving and problematic alcohol use via the paths of distress tolerance and both positive and negative alcohol‐related metacognitions. Three hundred men with problematic alcohol use during the abstinence phase completed psychological and clinical measures. Results showed that craving and negative alcohol metacognitions mediated the relationship between negative affect and problematic alcohol use. Negative affect had a direct and positive effect on craving and indirect effect via distress intolerance and positive alcohol metacognitions. In turn, distress intolerance and positive alcohol metacognitions indirectly and positively affected problematic alcohol use via craving. The study indicates that distress tolerance and distinct alcohol metacognitions may be differently related to various patterns of alcohol‐related problems, such that alcohol drinkers with high levels of negative affect, distress intolerance, and positive alcohol metacognitions show higher levels of craving, while high negative affect in relation to high negative alcohol metacognitions and alcohol craving is related to the perpetuation of alcohol use or problematic alcohol use.
Direct MOCVD Growth of Iron Oxide on Three‐Dimensional Nickel Foam as Electrode for the Oxygen Evolution Reaction
Authors: Stienen Christian , Bendt Georg
Published: September 2020

Iron oxide thin films were grown directly on three‐dimensional nickel foam via metalorganic chemical vapor deposition (MOCVD) in the temperature range of 250–450 °C using Fe(CO)5 as precursor. Iron oxide (α‐Fe2O3) films were formed at low substrate temperatures (250–350 °C), whereas the additional growth of an underlying NiO film occurred at substrate temperatures above 350 °C. The electrochemical activities of the as‐formed binder‐free and noble metal‐free electrodes were tested for the oxygen evolution reaction (OER) in alkaline media. An overpotential reduced by 250 mV at a current density of 50 mA cm−2 and a lower Tafel slope of 55 mV dec−1 compared to bare nickel foam were found for the best‐performing electrocatalyst, while the long‐term stability of the as‐formed electrodes was proven by chronopotentiometry. The surface morphology of the iron oxide films was characterized by scanning electron microscopy, whereas the crystallographic phase as well as the elemental composition were determined by X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, and time‐of‐flight secondary ion mass spectrometry in the pre‐ and the post‐catalytic state.
Digital current‐limited sliding‐mode control for synchronous buck converter with curved switching surface
Authors: Li Jinghao , Wu Aiguo
Published: September 2020

In this paper, a digital current‐limited sliding‐mode control (DCLSMC) for synchronous buck converter with curved switching surface is proposed. First, by discretizing the derivatives of a hybrid switching surface (SS) (consisting of second‐order and first‐order SS) and utilizing the reaching law method, a discrete‐time sliding‐mode control (SMC) is derived. Then, this SMC is integrated with a current‐limited control to construct the DCLSMC. Simulation results show that it can provide a current‐limited near‐time‐optimal dynamic response. The proposed SMC is implemented by pulse‐width modulation (PWM) technique, so it can provide a fixed switching frequency and has a low sampling requirement. The reachability of the SS for the proposed SMC and the stability of the quasi‐sliding mode motion is proven. Moreover, an additional PI control is introduced to eliminate the steady‐state error, and some implementation issues are discussed. Experimental results are given to verify the high dynamic performance and practical value of the proposed method.