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Purpose: Coronavirus disease 2019 (COVID‐19) has caused a serious global health crisis. It has been proven that the deep learning method has great potential to assist doctors in diagnosing COVID‐19 by automatically segmenting the lesions in computed tomography (CT) slices. However, there are still several challenges restricting the application of these methods, including high variation in lesion characteristics and low contrast between lesion areas and healthy tissues. Moreover, the lack of high‐quality labeled samples and large number of patients lead to the urgency to develop a high accuracy model, which performs well not only under supervision but also with semi‐supervised methods. Methods: We propose a content‐aware lung infection segmentation deep residual network (content‐aware residual UNet (CARes‐UNet)) to segment the lesion areas of COVID‐19 from the chest CT slices. In our CARes‐UNet, the residual connection was used in the convolutional block, which alleviated the degradation problem during the training. Then, the content‐aware upsampling modules were introduced to improve the performance of the model while reducing the computation cost. Moreover, to achieve faster convergence, an advanced optimizer named Ranger was utilized to update the model's parameters during training. Finally, we employed a semi‐supervised segmentation framework to deal with the problem of lacking pixel‐level labeled data. Results: We evaluated our approach using three public datasets with multiple metrics and compared its performance to several models. Our method outperforms other models in multiple indicators, for instance in terms of Dice coefficient on COVID‐SemiSeg Dataset, CARes‐UNet got the score 0.731, and semi‐CARes‐UNet further boosted it to 0.776. More ablation studies were done and validated the effectiveness of each key component of our proposed model. Conclusions: Compared with the existing neural network methods applied to the COVID‐19 lesion segmentation tasks, our CARes‐UNet can gain more accurate segmentation results, and semi‐CARes‐UNet can further improve it using semi‐supervised learning methods while presenting a possible way to solve the problem of lack of high‐quality annotated samples. Our CARes‐UNet and semi‐CARes‐UNet can be used in artificial intelligence‐empowered computer‐aided diagnosis system to improve diagnostic accuracy in this ongoing COVID‐19 pandemic. [ABSTRACT FROM AUTHOR]

Advanced sensation and actuation abilities of various living organisms in nature have inspired researchers to design bioinspired self‐sensing soft actuators. However, the majority of conventional soft actuators primarily possess actuation capabilities while lacking a real‐time sensing signal feedback. Here, a promising strategy is reported to develop highly stretchable and conductive hydrogels for bioinspired self‐sensing soft actuators, which integrate actuation and strain‐sensing functions into a single materials system. The conductive hydrogels are designed and fabricated by in situ copolymerization of amino‐functionalized MXene‐encapsulated liquid metal nanodroplets (LM@A‐MXene) and poly(N‐isopropylacrylamide) hydrogels with controllable activated nanogels as nano‐cross‐linkers. The resulting hydrogel presents a compacted conducting network and highly porous microstructure, giving rise to robust integration of high conductivity, excellent strain sensitivity, broad stretchability, high stability, and fast response speed. Interestingly, the gradient network structure, formed by self‐precipitation of LM@A‐MXene, endows the hydrogel with shape‐programmable actuation, light‐driven remote control, and self‐sensing function. As a proof‐of‐concept application, the soft gripper based on the self‐sensing hydrogel actuators is developed, which can not only grasp, lift, and release objects, but also perceive every movement state by monitoring resistance changes. The proposed self‐sensing soft actuator can offer new insights for developing smart soft robotics and other artificial intelligent devices. [ABSTRACT FROM AUTHOR]

A protein is generally classified into one of the following four structural classes: all α, all β, α+β and α/β. In this paper, based on the weighting to the 20 constituent amino acids, a new method is proposed for predicting the structural class of a protein according to its amino acid composition. The 20 weighting parameters, which reflect the different properties of the 20 constituent amino acids, have been obtained from a training set of proteins through the linear-programming approach. The rate of correct prediction for a training set of proteins by means of the new method was 100%, whereas the highest rate of previous methods was 82.8 %. Furthermore, the results showed that the more numerous training proteins, the more effective the new method. [ABSTRACT FROM AUTHOR]

Organic cycles play an important role in chemistry, pharmacology and material science for their unique properties. Construction of organic cycles from thioalkynes attracted increasing attention due to the facile access of thioalkynes. 2H‐Azirines were synthesized successfully from thioalkynyl oxime ethers. Cyclobutanes were formed through chiral titanium catalyzed cycloaddition of thioalkynes. Cyclopentenes were afforded by annulation of thioalkynes. Thioalkynes could be also applied to synthesize thiophenes, oxazoles, benzo[b]thiophenes, 2H‐chromenes, 2‐phenylbenzothiazoles, diazacyclobutene, etc. In this review, construction of organic cycles from thioalkynes were highlighted. Firstly, the property and application of organic cyclic compounds were simply introduced. After presenting the general methods to access organic cycles, applications of thioalkynes as synthons to prepare organic cycles were classified and presented in detail. Based on different kinds of organic cycles obtained from thioalkynes, organic reactions for synthesis of three‐, four‐, five‐, six‐membered as well as fused cycles would be summarized and the plausible reaction mechanisms could be presented if available. [ABSTRACT FROM AUTHOR]

Sulfur‐containing alkynes, are important starting materials and intermediates in organic reactions. Some of sulfur‐containing alkynes display interesting bioactivities and are potentially applied as drugs. Various synthetic methodologies towards sulfur‐containing alkynes have been developed, including C(sp)−S coupling, thiolation, S‐alkynylation, trifluoromethylthiolation, etc. In this review, the approaches towards alkynyl sulfides in recent 3 years, as well as to form alkynyl trifluoromethyl sulfides and alkynylthiocyanates were highlighted. Firstly, the property and application of alkynes were introduced. After presenting the superiority of sulfur‐containing alkynes, their synthetic methods were classified and presented in details. According to different kinds of sulfur‐containing alkynes, synthetic methodologies for alkynyl sulfides, alkynyl trifluoromethyl sulfides and alkynylthiocyanates were summarized and the proposed reaction mechanisms were demonstrated if available. [ABSTRACT FROM AUTHOR]

Sophisticated sensing and actuation capabilities of many living organisms in nature have inspired scientists to develop biomimetic somatosensory soft robots. Herein, the design and fabrication of homogeneous and highly conductive hydrogels for bioinspired somatosensory soft actuators are reported. The conductive hydrogels are synthesized by in situ copolymerization of conductive surface‐functionalized MXene/Poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonate) ink with thermoresponsive poly(N‐isopropylacrylamide) hydrogels. The resulting hydrogels are found to exhibit high conductivity (11.76 S m−1), strain sensitivity (GF of 9.93), broad working strain range (≈560% strain), and high stability after over 300 loading–unloading cycles at 100% strain. Importantly, shape‐programmable somatosensory hydrogel actuators with rapid response, light‐driven remote control, and self‐sensing capability are developed by chemically integrating the conductive hydrogels with a structurally colored polymer. As the proof‐of‐concept illustration, structurally colored hydrogel actuators are applied for devising light‐driven programmable shape‐morphing of an artificial octopus, an artificial fish, and a soft gripper that can simultaneously monitor their own motions via real‐time resistance variation. This work is expected to offer new insights into the design of advanced somatosensory materials with self‐sensing and actuation capabilities, and pave an avenue for the development of soft‐matter‐based self‐regulatory intelligence via built‐in feedback control that is of paramount significance for intelligent soft robotics and automated machines. [ABSTRACT FROM AUTHOR]

Cationic mononuclear zirconocene and titanocene perfluorooctanesulfonate complexes are successfully applied in various transformation reactions of carbonyl compounds. [ABSTRACT FROM AUTHOR]

With the growth of high performance electronics, more consideration should be given to the safety issues associated with thermal runaway. Previous strategies have often been limited by shutdown efficiency and shutdown temperature. Here, we present a MXene supercapacitor loaded with a smart thermally responsive electrolyte to cope with thermal runaway at high temperatures. At room temperature, the ions in the electrolyte containing the poly (N‐isopropylacrylamide‐co‐glycidyl methacrylate) (PNGM) can migrate freely and the devices can operate normally. The smart electrolyte system forms a hydrophobic network that effectively inhibits ion migration to achieve thermal shutdown at high temperatures. The electrolyte system exhibits different electrochemical properties during heating up, reaching nearly 90 % capacity suppression at 85 °C. The proposed smart electrolyte system provides a promising solution to the thermal safety suitable for current electronic devices by achieving a proactive protection strategy. [ABSTRACT FROM AUTHOR]

The two air-stable μ2-hydroxy-bridged binuclear hafnocene perfluorobutanesulfonate and perfluorobenzenesulfonate complexes were successfully synthesized. The high catalytic activity and recyclability of these complexes were exemplified for various carbon-carbon bond formation reactions. Compared with our previously reported hafnocene perfluorooctanesulfonate, these complexes show stronger Lewis acidity and better catalytic activity, and should find broad applications in organic synthesis. [ABSTRACT FROM AUTHOR]

Herein, we report near‐infrared (NIR) light‐driven shape‐morphing of programmable MXene‐containing anisotropic hydrogel actuators that are fabricated through in situ free‐radical copolymerization of a judiciously designed MXene nanomonomer with thermosensitive hydrogel network. A low electric field (few V mm−1) was found to enable a spatial distribution of MXene nanosheets and hence introduce anisotropy into the hydrogel network. Programmable anisotropic hydrogel actuators were developed by controlling ITO electrode pattern, direct‐current (DC) electric field direction and mask‐assisted photopolymerization. As a proof‐of‐concept, we demonstrate NIR light‐driven shape morphing of the MXene‐containing anisotropic hydrogel into various shapes and devise a four‐arm soft gripper that can perform distinct photomechanical functions such as grasping, lifting/lowering down and releasing an object upon sequential NIR light exposure. [ABSTRACT FROM AUTHOR]

Herein, we report near‐infrared (NIR) light‐driven shape‐morphing of programmable MXene‐containing anisotropic hydrogel actuators that are fabricated through in situ free‐radical copolymerization of a judiciously designed MXene nanomonomer with thermosensitive hydrogel network. A low electric field (few V mm−1) was found to enable a spatial distribution of MXene nanosheets and hence introduce anisotropy into the hydrogel network. Programmable anisotropic hydrogel actuators were developed by controlling ITO electrode pattern, direct‐current (DC) electric field direction and mask‐assisted photopolymerization. As a proof‐of‐concept, we demonstrate NIR light‐driven shape morphing of the MXene‐containing anisotropic hydrogel into various shapes and devise a four‐arm soft gripper that can perform distinct photomechanical functions such as grasping, lifting/lowering down and releasing an object upon sequential NIR light exposure. [ABSTRACT FROM AUTHOR]

Wearable electronic devices need ceaseless improvement in performance and flexibility. However, few studies were focused on high mass loading electrodes. Herein, a 3D printing method was demonstrated to fabricate the high‐performance supercapacitor on flexible carbon cloth using polypyrrole (PPy) nanotubes as electrode materials. The mass loading could achieve 336.56 mg cm−2 through direct ink printing (DIW) technology. In addition, the 3D printed supercapacitor exhibits excellent mechanical stability, the capacitance of the printed device remains 93% at the bending angle of 120°. Its promising performance and outstanding electrochemical stability will provide an ideal method to fabricate wearable storage devices. [ABSTRACT FROM AUTHOR]

A metal‐, base‐ and reductant‐free approach for the efficient synthesis of various N‐acylated 2‐aminoquinolines was reported. In this work, readily available nitriles are used as the amide source, and methyl carbazate as both the radical activating reagent and oxygen source. This is the first report on the ester‐radical‐activated highly regioselective addition of nitriles to quinolone N‐oxides. This procedure is expected to complement the current methods for functionalization of N‐oxides via an electrophilic activation mechanism. [ABSTRACT FROM AUTHOR]

Abstract: Bis(pentamethylcyclopentadienyl) zirconium perfluorooctanesulfonate is an air‐stable and water‐tolerant Lewis acid. This complex exhibited good thermal stability and high solubility in polar organic solvents. The compound showed relatively strong acidity, with an acid strength of 0.8

Abstract: The use of heterogeneous bimetallic Pd‐based nanocatalyst for directing the inactivated sp3 C−H coupling has been scarcely explored. This work reported the formation of symmetrical C−C bonds from the inactivated sp3 C−H bonds catalyzed by employing reduced graphene oxide supported PtPd@Pt porous nanospheres. The reaction of sp3 C−H activation proceeded under mild conditions without any solvent, ligand or directing group. It is a higher atom‐, step‐ and cost‐effectiveness strategy for developing heterogeneous catalysts in the synthesis of bibenzyls with various functional groups (e. g. aryl, alkyl, methoxyl, halogen, ester, and pyridyl). [ABSTRACT FROM AUTHOR]

An efficient route for the synthesis of (Z)-vinylic sulfides is presented. [ABSTRACT FROM AUTHOR]

Triphenyl bismuth bisperfluorooctanesulfonate is an air- and water-stable Lewis acid. It exhibits high catalytic efficiency for the synthesis of nitrogen heterocycles such as diindolylmethane derivatives, dihydropyrimidinones, dihydropyridines and 1,2-disubstitued benzimidazoles under mild condition. Furthermore, it can be reused without loss of activity in a test of five cycles.This catalytic system affords a simple and efficient way for the synthesis of N-containing compounds. [ABSTRACT FROM AUTHOR]

Review: 76 refs. [ABSTRACT FROM AUTHOR]

The air-stable hafnocene Lewis acid catalyst is shown to be effective in Lewis acid-catalyzed C-C bond forming reactions. [ABSTRACT FROM AUTHOR]

The inhibitory effect of barley straw ( Hordeum vulgare) on cyanobacteria has been observed in many field and laboratory studies for over 30 years, although the compounds responsible for this anti-cyanobacterial effect have remained unknown. In this study, a pair of chiral flavonolignans were isolated from barley straw extract using a bioassay-guided isolation procedure against Microcystis sp. The structures of the allelopathic compounds were elucidated by NMR (nuclear magnetic resonance) and HPLC-MS (high performance liquid chromatography-mass spectrometry), and turned out to be salcolin A and B. The enantiomers differ in their anti-cyanobacterial abilities. Both enantiomers exhibited inhibitory effects on Microcystis sp., and the EC50 (concentration for 50% of maximal effect) of salcolin A and B were 6.02 × 10−5 and 9.60 × 10−5 mol l−1, respectively. Furthermore, the modes of actions of the enantiomers were investigated and compared at a single cell level by flow cytometry. Salcolin A was found to induce an increase on cyanobacterial intracellular ROS (reactive oxygen species) levels and to inhibit esterase activity, whereas salcolin B caused leakages of cyanobacterial cytoplasms. Thus, salcolin A was more 'algistatic', and salcolin B was more 'algicidal'. This study suggests that salcolin is the key allelochemical in barley straw's inhibitory effect on cyanobacteria and could be used as an agent in the future control of cyanobacterial harmful algae blooms. [ABSTRACT FROM AUTHOR]

Sulfate in groundwater has been previously shown to change the reactivity of Fe0 in permeable reactive barriers for reducing chlorinated organics. To better understand the effect and mechanism of SO, the degradation of 1,1,1-trichloroethane (TCA) by Fe0 in unbuffered aqueous solutions with and without SO was investigated. In a Fe0-TCA-H2O system with initial pH of 2.0 to 10.0, the maximum removal rate of TCA was achieved at the initial pH 6.0 with pseudo-first-order constant Kobs 9.0 × 10−3/min. But in a Fe0-TCA-Na2SO4-H2O system, the removal rate of TCA decreased remarkably with a reduction in Kobs to 1.0 × 10−3/min, and the pH varied from 6.0 to 9.6, indicating an inhibition of TCA dehydrochlorination by SO. Sulfate remarkably inhibited TCA degradation via changing the route of Fe0 dissolution. It accelerated the dissolution of Fe0 and transformed the intermediate form Fe(OH)ads to Fe2(SO4)ads, which weakened the affinity between Fe and TCA, and thus depressed the degradation of TCA by Fe0. [ABSTRACT FROM AUTHOR]

In the synthesis of binuclear organobismuth complexes ( 1- 6) through treatment of organobismuth chlorides with NaOH or Na2S⋅9H2O, the two 5,6,7,12-tetrahydrodibenz [ c,f][1,5]azabismocine frameworks are cross-linked by either a sulfur or an oxygen atom. The complexes ( 1- 6) show high catalytic efficiency in the synthesis of cyclic carbonates from 2-(chloromethyl)oxirane and CO2. Compared with their precursor chlorides ( 7- 9), methoxide 10 and methanethioate 11 which are mononuclear organobismuth complexes, the binuclear organobismuth complexes show higher cooperative catalytic effect. However, the complexes with an oxygen bridge ( 1- 3) are not stable in air and lose their catalytic efficiency because of hydrolysis or CO2 adsorption (forming organobismuth carbonates in the latter case). Nonetheless, the binuclear organobismuth complexes ( 4- 6) with a sulfur bridge are highly stable in air and can be applied in the synthesis of cyclic carbonates (with the co-presence of Bu4NI) across various kinds of epoxides, thus exhibiting satisfactory efficiency and selectivity. [ABSTRACT FROM AUTHOR]

Frontispiz: Near-Infrared Light-Driven Shape-Morphing of Programmable Anisotropic Hydrogels Enabled by MXene Nanosheets Keywords: anisotropic hydrogels; MXene; NIR light; soft robotics EN anisotropic hydrogels MXene NIR light soft robotics 1 1 1 02/10/21 20210215 NES 210215 B Soft-Robotik b Programmierbare anisotrope Hydrogel-Aktuatoren mit Nahinfrarotlicht-getriebener Formveränderung werden von Ling Wang, Xinhua Xu, Quan Li et al. in der Zuschrift auf S. 3432 vorgestellt. Anisotropic hydrogels, MXene, NIR light, soft robotics. [Extracted from the article]

An air‐stable complex of zirconium (IV)‐salophen perfluorooctanesulfonate (1) was successfully synthesized by reacting Zr (salphen)Cl2 and C8F17SO3Ag. Complex 1 was characterized and studied by different techniques (NMR, IR, HRMS, TG‐DSC, conductivity and acidity measurements), and was found to be air‐stable, water tolerant, thermally stable and strongly Lewis‐acidic. Complex 1 exhibited high catalytic efficiency for the synthesis of 3,4‐dihydropyrimidin‐2‐(1H)‐ones/thiones via the Biginelli reaction of aldehydes, 1,3‐dicarbonyl compounds and urea/thiourea under solvent‐free conditions. Furthermore, complex 1 could be reused 5 times with minimal changes in catalytic efficiency. Compared with previously reported methods, the important features of this protocol are the solvent‐free conditions, the short reaction times, the wide substrate compatibility, the high efficiency and the good reusability. [ABSTRACT FROM AUTHOR]

A heterogeneous Pd‐Cu NWs‐catalyzed expeditious and solvent‐free synthesis of propargylamines via A3‐coupling of aldehydes, alkynes, and amines has been proposed. A wide range of aldehydes, alkynes and amine substrates undergo A3‐coupling to produce propargylamines in good to excellent yields with good functional tolerance, such as that towards alkoxy, hydroxy, C‐X (X = F, Cl, Br) as well as amide and C=C bonds. Furthermore, the catalyst could be recovered easily and reused for at least 5 cycles without showing significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Wearable fiber‐shaped electronic devices have drawn abundant attention in scientific research fields, and tremendous efforts are dedicated to the development of various fiber‐shaped devices that possess sufficient flexibility. However, most studies suffer from persistent limitations in fabrication cost, efficiency, the preparation procedure, and scalability that impede their practical application in flexible and wearable fields. In this study, a simple, low‐cost 3D printing method capable of high manufacturing efficiency, scalability, and complexity capability to fabricate a fiber‐shaped integrated device that combines printed fiber‐shaped temperature sensors (FTSs) with printed fiber‐shaped asymmetric supercapacitors (FASCs) is developed. The FASCs device can provide stable output power to FTSs. Moreover, the temperature responsivity of the integrated device is 1.95% °C−1. 3D printing of fiber electrodes for an all‐fiber integrated electronic device via hybridization of an asymmetric supercapacitor and a temperature sensor is reported. A self‐energy monitoring system is developed that exhibits excellent electrochemical performance and rapid temperature response. [ABSTRACT FROM AUTHOR]

The article presents chemical equation for the article "Air-Stable Organobismuth(V) Bisperfluorooctanesulfonate as an Efficient Catalyst for the Synthesis of N-Containing Compounds" by P. Wang and others, published in the journal "Advanced Synthesis & Catalysis" in 2016.

8-Aminoquinoline substrates can be readily substituted at the 5-position in the presence of CuBr2. [ABSTRACT FROM AUTHOR]

The scalable reaction is based on the chelation assistance of an N-(quinolin-8-yl) group and tolerates multiple functional groups. [ABSTRACT FROM AUTHOR]

The title reaction is applied to the synthesis of O-aryl substituted O-allenes and N-acetyl-N-aryl substituted N-allenes as well as N-allene substituted N-heterocycles. [ABSTRACT FROM AUTHOR]

Newly prepared binuclear organic antimony sulfonates prove to be efficient catalysts for Michael addition reaction of indoles with Michael acceptors as well as for allylation of aldehydes. [ABSTRACT FROM AUTHOR]

The present reaction proceeds site-selectively using less expensive Cu(OAc)2 without the need for any expensive noble metal catalyst nor additives to give the corresponding sulfenylated products in good yields. [ABSTRACT FROM AUTHOR]

It is demonstrated, that the title catalyst ZRC exhibits high catalytic activity for the synthesis of benzimidazoles, benzodiazepines, dihydropyrimidines, and dihydropyridines under neat conditions. [ABSTRACT FROM AUTHOR]

A regio-, chemo-, and (Z)-stereoselective synthesis of vinylic dichalcogenides is developed using the CsOH-catalyzed three-component coupling of terminal alkynes, diaryl disulfides, and diaryl diselenides or tellurides. [ABSTRACT FROM AUTHOR]

The thioethers are synthesized from the reaction of aliphatic amides and disulfides. [ABSTRACT FROM AUTHOR]

The title catalyst is successfully applied to the aza-Friedel-Crafts reaction of indoles, aldehydes, and aniline to give the corresponding products in good yields. [ABSTRACT FROM AUTHOR]

Review: 113 refs. [ABSTRACT FROM AUTHOR]