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Background: Peritoneal carcinomatosis was the main reason leading to gastric cancer (GC)-related death. We aimed to explore the roles of dysregulated microRNAs (miRNAs) and related immune regulation activities in GC-associated malignant ascites. Methods: GSE126399 were downloaded from GEO database. Differentially expressed miRNAs in GC ascites samples was firstly screened, and critical miRNAs were further investigated by LASSO (least absolute shrinkage and selection operator) logistic regression and random forest (RF) algorithm. Receiver operating characteristic of critical miRNAs was also constructed. Moreover, functional analysis, immune cell infiltration associated with differentially expressed mRNAs were further analyzed. After selecting key modules by weighted gene co-expression network analysis, mRNAs related with survival performance and transcription factor (TF)-miRNA-mRNA network were constructed. Results: Hsa-miR-181b-5p was confirmed as critical differentially expressed miRNAs in GC ascites. Then, the tumor samples were divided into high- and low- expression groups divided by mean expression levels of hsa-miR-181b-5p, and subjects with high hsa-miR-181b-5p levels had better survival outcomes. In total, 197 differentially expressed mRNAs associated with hsa-miR-181b-5p levels were obtained, and these mRNAs were mainly enriched in muscle activity and vascular smooth muscle contraction. Hsa-miR-181b-5 was positively related with activated CD4 T cells and negatively related with eosinophil. 17 mRNAs were selected as mRNAs significantly related with prognosis of GC, such as PDK4 and RAMP1. Finally, 75 TF-miRNA-mRNA relationships were obtained, including 15 TFs, hsa-miR-181b-5p, and five mRNAs. Conclusion: Our data suggest that the differentially expressed hsa-miR-181b-5p in ascites samples of GC patients may be a valuable prognostic marker and a potential target for therapeutic intervention, which should be validated in the near future. [ABSTRACT FROM AUTHOR]

AbstractThe ionization of benzene (C6H6) through helium low-temperature plasma (He-LTP) offers a promising solution to the pervasive issue of its pollution in our daily lives. This study aimed to optimize the conditions for generating specific compounds, namely M+ and [M + 30]+, during the ionization of benzene in low-temperature plasma (LTP) with determination by mass spectrometry (MS). When the discharge voltage is 2.5 kV, a sample gas to discharge gas flow rate ratio of 2:3 is the best condition for generating M+ ions. When the discharge voltage is 3.5 kV, the gas flow rate ratio of 1:3 is the most suitable for generating [M + 30]+ ions. The LTP exhibits optimal ionization efficiency at a total gas flow rate of 40 mL/min. Additionally, we conducted a comparative analysis on the optical emission of benzene in the LTP which revealed the generation of free radicals associated with N, H, and O. The produced nitroso radical (ON•) combines with ionized benzene to yield the [M + 30]+ ion, identified to be nitrosobenzene. Notably, 95% conversion was achieved in the transformation from benzene to nitrosobenzene. [ABSTRACT FROM AUTHOR]

The study aims to explore the relationship among mindfulness, depression, meaning in life (MIL) and psychological resilience (PR), and verify whether MIL and PR have a chain mediating effect between mindfulness and depression. 1034 college students in a province were investigated by using Adolescent Mindfulness Scale, Depression Scale, Meaning in Life Scale and Psychological Resilience Scale. Hierarchical multiple regression and bootstrap was used to analyze the data and test whether MIL and PR play a chain mediating role between mindfulness and depression among university students. In the present research, the direct effect value of mindfulness on college students' depression was 0.14, and the effect amount was 61%. The effect values of MIL and PR between mindfulness and college students' depression were 0.03 and 0.05, and the effect amount is 13% and 22%. In the meantime, the chain mediating effect of MIL and PR was significant, the effect value is 0.01 and the effect amount is 4%. The effects of mindfulness on depression of university students were mediated by MIL, PR and the chain of MIL and PR. [ABSTRACT FROM AUTHOR]

Background and Purpose: The recanalization rate after intravenous thrombolysis (IVT) is not enough and there is still the possibility of re-occlusion. We aim to investigate the effectiveness and safety of infusing tirofiban after IVT.Methods: We performed a prospective controlled study of 60 patients with acute non-cardiogenic ischemic stroke who were hospitalized in Yantai Yuhuangding Hospital from January 2018 to December 2019. The patients were divided into 2 groups: those who received tirofiban for 24 h after IVT (rt-PA + T group) and those who did not receive postprocedural intravenous tirofiban (rt-PA group). The rt-PA + T group received low-dose rt-PA (0.6 mg/kg). The rt-PA group received standard dose rt-PA (0.9 mg/kg). The main outcome measure were safety, included the symptomatic intracranial hemorrhage (sICH), any ICH, severe systemic bleeding, and mortality. The secondary outcome measure is curative efficacy which were evaluated by the 7d-NIHSS score and functional outcomes at 90 days. During hospitalization, the deterioration of neurological function was recorded.Results: All patients completed the follow-up with complete data, there were 30 patients in each of groups. The general characteristics between the two group patients had no statistically significant differences. Compared with the rt-PA + T group and the rt-PA group, in terms of safety, the rates of the sICH, severe systemic bleeding, and mortality in both groups were 0, and there was no statistically significant difference in the rates of any ICH between the two groups (10.0% vs. 3.3%, P = 0.306). In terms of efficacy, the rate of the early neurological deterioration events (END) was no statistical significance (0 vs. 6.6%, P = 0.246). There was no significant difference in the NIHSS score between the two groups before the IVT, and also at 24 h, however, the 7d-NIHSS score was lower in the rt-PA + T group compared with the rt-PA group (2.33 ± 1.85 vs. 4.80 ± 4.02, P = 0.004). At 90 days, 83.3% of patients in the rt-PA + T group had favorable functional outcomes compared with 60.0% of patients in the rt-PA group (P = 0.045).Conclusions: Low-dose rt-PA combined with tirofiban in acute non-cardiogenic ischemic stroke did not increase the risk of ICH, and mortality, and it was associated with neurological improvement.Trial Registration: The trial has been registered at the ChiCTR and identified as ChiCTR1800014666 (28/01/2018). [ABSTRACT FROM AUTHOR]

Introduction. Antiviral activity is a main function of many types of traditional Chinese medicine (TCM), and they may contribute more in the process of certain viral epidemics. Therefore, based on the effectiveness and economy of TCM, we aimed to determine the situation of health economic studies about antivirals, especially the difference between TCM and non-TCM. Methods. A literature search of three databases was conducted with a time range of January 2000–December 2020, and terms related to health economics and TCM were used as key terms. QHES and CHEERS were used as quality assessment tools. Results. 203 papers were included in our research. After evaluation using QHES and CHEERS, antiviral TCM obtained an overall score of 41.37 ± 4.46/99 in QHES, compared with 48.89 ± 7.25/99 (18.18% higher than TCM) of antiviral non-TCM. Conclusion. With a statistically significant difference, the overall quality of pharmacoeconomic research about antiviral non-Chinese medicine is better than that about antiviral Chinese medicine, which may have resulted from researchers' capacities or the absence of a more suitable standard for pharmacoeconomic research. It tells that the quality of pharmacoeconomic studies about TCM still warrants improvement. [ABSTRACT FROM AUTHOR]

[Display omitted] There is a lack of understanding of the interplay between the copolymer composition profile and thermal transition observed in aqueous solutions of N -isopropyl acrylamide (NIPAM) copolymers, as well as the correlation between this transition and the formation and structure of copolymer self-assemblies. For this purpose, we investigated the response of five copolymers with the same molar mass and chemical composition, but with different composition profile in aqueous solution against temperature. Using complementary analytical techniques, we probed structural properties at different length scales, from the molecular scale with Nuclear Magnetic Resonance (NMR) to the colloidal scale with Dynamic Light Scattering (DLS) and Small Angle Neutron Scattering (SANS). NMR and SANS investigations strengthen each other and allow a clear picture of the change of copolymer solubility and related copolymer self-assembly as a function of temperature. At the molecular scale, dehydrating NIPAM units drag N , N -dimethyl acrylamide (DMA) moieties with them in a gradual collapse of the copolymer chain; this induces a morphological transition of the self-assemblies from star-like nanostructures to crew-cut micelles. Interestingly, the transition spans a temperature range which depends on the monomer distribution profile in the copolymer chain, with the asymmetric triblock copolymer specimen revealing the broadest one. We show that the broad morphological transitions associated with gradient copolymers can be mimicked and even surpassed by the use of stepwise gradient (asymmetric) copolymers, which can be more easily and reproducibly synthesized than linear gradient copolymers. [ABSTRACT FROM AUTHOR]

Transition–metal catalyzed tandem asymmetric reactions were powerful tools to access various chiral compounds. Many strategies have been developed for the coupling of 1,n‐dienes with aryl halides via a tandem Heck/Tsuji–Trost process. However, the control of regio‐ and stereo‐chemistry remains a challenging task. This minireview details the recent advances in the field of asymmetric Heck/Tsuji–Trost reactions catalyzed by palladium complex, which have opened new opportunities and expanded our understanding in this area of research in recent years. [ABSTRACT FROM AUTHOR]

A series of copolymers containing 50 mol % acrylic acid (AA) and 50 mol % butyl acrylate (BA) but with differing composition profiles ranging from an AA‐BA diblock copolymer to a linear gradient poly(AA‐grad‐BA) copolymer were synthesized and their pH‐responsive self‐assembly behavior was investigated. While assemblies of the AA‐BA diblock copolymer were kinetically frozen, the gradient‐like compositions underwent reversible changes in size and morphology in response to changes in pH. In particular, a diblock copolymer consisting of two random copolymer segments of equal length (16 mol % and 84 mol % AA content, respectively) formed spherical micelles at pH >5, a mix of spherical and wormlike micelles at pH 5 and vesicles at pH 4. These assemblies were characterized by dynamic light scattering, cryo‐transmission electron microscopy and small angle neutron scattering. [ABSTRACT FROM AUTHOR]

Eine Serie von Copolymeren, die 50 % Acrylsäure (AA) und 50 % Butylacrylat (BA) enthielten, jedoch unterschiedliche Zusammensetzungsprofile aufwiesen, wurden synthetisiert und ihr pH‐abhängiges Selbstassemblierungsverhalten untersucht. Dabei reichten die synthetisierten Profile von einem AA‐BA‐Diblockcopolymer bis zu einem Poly(AA‐grad‐BA)‐Copolymer mit linearem Gradienten. Während assemblierte Gruppen des AA‐BA‐Diblockcopolymers kinetisch gehemmt waren, zeigten die gradientenartigen Kompositionen reversible Änderungen der Größe und Morphologie als Reaktion auf Veränderung des pH‐Werts. Im Speziellen bildete ein Diblockcopolymer, das aus zwei ungeordneten Copolymersegmenten gleicher Länge (16 % bzw. 84 % AA‐Gehalt) bestand, kugelförmige Mizellen bei einem pH‐Wert >5, eine Mischung aus kugelförmigen und wurmartigen Mizellen bei pH 5 und Vesikel bei pH 4. Diese Anordnungen wurden durch dynamische Lichtstreuung (DLS), Kryo‐Transmissionselektronenmikroskopie (Kryo‐TEM) und Kleinwinkelneutronenstreuung (SANS) charakterisiert. [ABSTRACT FROM AUTHOR]

During the past few decades, there has been considerable growth in the development of denitrogenative reactions of triazole skeletons to construct valuable cyclic compounds, particularly heterocycles. Despite the inherent difficulty of the ring‐opening of triazole derivatives, many novel and efficient approaches have arisen in this area mainly with the use of transition metal (such as rhodium, palladium, silver, copper) catalysis, photolysis, or free radical mediated reactions. Generally, these procedures begin with the ring‐opening of 1,2,3‐triazoles or benzotriazoles followed by N2 extrusion and subsequent diverse transformations, which enable the rapid synthesis of various heterocycles in a single step. To avoid overlap with other related reviews, this minireview covers the recent advances in the denitrogenative cyclization of 1,2,3‐triazoles since 2016 and the denitrogenative cyclization of benzotriazoles since 2012. [ABSTRACT FROM AUTHOR]

A novel nickel-catalyzed alkyl–alkyl cross coupling of non-activated secondary alkyl bromides with aldehydes via hydrazone intermediates has been developed. Aldehydes as alkyl carbanion equivalents replace traditional organometallic reagents. This coupling occurs on the carbon of the hydrazone rather than the nitrogen. In addition, non-activated primary and tertiary alkyl bromides also undergo the cross-coupling reaction to form new C(sp3)–C(sp3) bonds in moderate yields. [ABSTRACT FROM AUTHOR]

Abstract: Asymmetric copolymers are a class of materials with intriguing properties. They can be defined by a distribution of monomers within the polymer chain that is neither strictly segregated, as in the case of block copolymers, nor evenly distributed throughout each chain, as in the case of statistical copolymers. This definition includes gradient copolymers as well as block copolymers that contain segments of statistical copolymer. In this review, different methods to synthesize asymmetric copolymers are first discussed. The properties of asymmetric copolymers are investigated in comparison to those of block and random counterparts of similar composition. Finally, some examples of applications of asymmetric copolymers, both academic and industrial, are demonstrated. The aim of this review is to provide a perspective on the design and synthesis of asymmetric copolymers with useful applications. [ABSTRACT FROM AUTHOR]

Silicone rubbers are widely employed in various fields such as electronics, electrical engineering, mobile communications, aerospace, and automotive industries. However, silicone rubbers are typically challenging to reprocess and degrade. Moreover, with the advancement of technology, higher demands are placed on its thermal conductivity and dielectric properties. In this study, diglycidyl ether terminated polydimethylsiloxane is cured by 4,4′‐dithiodibutyric acid which contains dual dynamic covalent disulfide and ester bonds with triazobicyclodecene as the ester exchange catalyst to prepare silicone rubber vitrimers (SRVs) through a casting method. The SRVs demonstrate a relatively higher intrinsic thermal conductivity of 0.26 W (m⁻1 K⁻1) compared to ≈0.20 W (m⁻1 K⁻1) of conventional silicone rubber. Besides, the SRVs exhibit very low and stable dielectric constant and dielectric loss at both low and high frequencies (X‐band). The lowest dielectric constant and dielectric loss tangent at 10 GHz are 2.75 and 0.0650, respectively. Besides, the dual dynamic covalent bonds enable the SRVs to have excellent reprocessability and fast degradability. Moreover, the SRVs reveal UV‐shielding capability, as the transmittance of the SRVs is 0% from 200 to 400 nm of UV light. [ABSTRACT FROM AUTHOR]

Abstract: A method for the construction of sulfinamides via the copper‐catalyzed electrophilic amination of sulfenate anions using N‐benzoyloxyamines as the amination reagents. This procedure featured with the capture of in‐situ generated sulfenate anions from β‐sulfinyl esters under mild conditions, which provides an efficient strategy for the synthesis of diverse sulfinamides in moderate to good yields. [ABSTRACT FROM AUTHOR]

A photochemical strategy for the sequential dual compaction of single polymer chains is introduced. Two photoreactive methacrylates, with side chains bearing either a phenacyl sulfide (PS) or an α-methylbenzaldehyde (photoenol, PE) moiety, are selectively incorporated by one-pot iterative reversible-addition fragmentation chain transfer copolymerization into the outer blocks of a well-defined poly(methyl methacrylate) based ABC triblock copolymer possessing a nonfunctional spacer block ( Mn = 23 400 g mol−1, Đ = 1.2; ≈15 units of each photoreactive moieties of each type) as well as in model statistical copolymers bearing only one type of photoreactive unit. Upon UVA irradiation, PS and PE lead to highly reactive thioaldehydes and o-quinodimethanes, which rapidly react with dithiol and diacrylate linkers, respectively. The monomerfunctional copolymers are employed to establish the conditions for controlled intramolecular photo-crosslinking, which are subsequently applied to the bifunctional triblock copolymer. All compaction/folding experiments are monitored by size-exclusion chromatography and dynamic light scattering. The dual compaction consists of two events of dissimilar amplitude: the first folding step reveals a large reduction in hydrodynamic diameters, while the second compaction lead to a far less pronounced reduction of the single-chain nanoparticles size, consistent with the reduced degrees of freedom available after the first covalent compaction step. [ABSTRACT FROM AUTHOR]

This paper intends to reveal the interface trapping effect on the charge transport characteristics of LDPE/ZnO nanocomposite by combined study of the nanocomposite structures, trap level distributions, space charge distributions, conduction current and charge mobility. Experimental results show that nanofillers in the nanocomposites significantly altered the microstructure of the polymer matrix by introducing lots of smaller spherulites and increasing the crystallinity, leading to a significant increase in the interface areas between amorphous and crystalline regions. The trap density in the nanocomposites is about 2–6 times that in LDPE. The traps are essentially cavities, located at the interface areas between nanofillers and polymer matrix and interface areas between amorphous and crystalline regions. A new method was proposed to evaluate the carrier mobility as a function of discharge time and trap depth from the IDC results directly. The carrier mobility of LDPE is about 4–20 times higher than that of the nanocomposites. Compared with LDPE, bulk space charge accumulation is significantly suppressed in the nanocomposites. An interesting discovery is that there is a clear correspondence between the space charge accumulation and current increase in I-t characteristics under high electric field. The study indicates that the low charge carrier mobility and space charge suppression in LDPE/ZnO nanocomposites and the I-t behavior are all closely related to the interface trapping effects in the nanocomposites. [ABSTRACT FROM PUBLISHER]

Recently, all-inorganic perovskite structured nanomaterials CsPbX 3 (X = Cl, Br, I or mixed halogen) quantum dots (QDs) have been developed rapidly in many applications such as photovoltaics, light-emitting diodes, and photoelectric detectors due to their excellent optical and photoelectrical properties. Meanwhile, this hot topic material also shows interesting potential in sensing applications because of the sensitive surface and large specific area. The reversible property in gas sensing makes it a promising material to realize highly sensitive visual gas sensor on the fluorescent signal. However, the influencing mechanism of the phenomenon gas molecules is still controversial in many situations. In this paper, we proposed a series of fluorescence turn-on ammonia gas sensors based on spin-coated CsPbX 3 film. The wavelength of the fluorescent signal carrier was modulated by altering the ratio of halogen. By properly selecting the proportion of surface ligands and carefully analyzing the experiment results, we believe the dynamic passivation of ammonia molecule on the surface of perovskite QDs made dominated contribution to the sensing mechanism, and the series of CsPbX 3 QDs sensor shared a similar trend at room temperature. In addition, the sensors we prepared exhibit impressive performance in sensitivity, response time, and reversibility, showing a good potential for low cost, high precision, miniaturized gas detection based on the optical signal. [Display omitted] • We proposed a series of fluorescence turn-on ammonia sensors based on spin-coated CsPbX 3 QDs film. • The wavelength of the fluorescent signal carrier was modulated by altering the ratio of halogen. • Dynamic passivation of ammonia molecule on the surface of perovskite QDs made dominated contribution to the sensing mechanism, and the series of CsPbX 3 QDs sensor shared a similar trend at room temperature. • The sensors exhibit impressive performance in sensitivity, response time, and reversibility, showing a good potential for low cost, high precision, miniaturized gas detection based on the optical signal. [ABSTRACT FROM AUTHOR]

[Display omitted] • We propose a colorimetric method for sEVs detection. • SMBs (streptavidin magnetic beads)-capture probes were designed for specifically recognizing sEVs and inducing the subsequent signal amplification. • Exo-III assisted signal amplification coupled to the digestion of DNAzyme template enables colorimetric sEVs detection with a favorable sensitivity. • This method is simple, cost-effective, highly selective, and free of dye label and separation procedures. Small extracellular vesicles (sEVs) are closely associated with physiological and pathological processes of a variety of diseases, such as osteosarcoma. Developing a simple and sensitive sEVs detection strategy is crucial to the in-deep study and clinical diagnosis of many disease. We developed here a colorimetric sEVs detection strategy based on SMBs (streptavidin magnetic beads)-capture probe-assisted sEVs recognition and Exo-III assisted signal amplification. Three processes were included in the established strategy: target sEVs recognition-mediated liberation of trigger sequence, Exo-III based signal amplification and DNAzyme catalyzed color reaction for signal output. Eventually, the proposed method exhibited a wide sEVs detection range from 102 to 106 particles/L, and possesses an excellent capability in discriminating CD63 positive sEVs. In addition, the detection assay can be potentially applied to accurate quantification of sEVs in constructed clinical samples, maintaining a favorable recovery rate of 98.7% to 102.4%. This method is easy-to-operate, highly sensitive, and free of complicated sEVs separation procedures and dye label. [ABSTRACT FROM AUTHOR]

We report the synthesis of hierarchical zeolite Beta with low organic template (tetraethylammonium hydroxide, TEAOH) content by the steam-assisted conversion (SAC) method. Neither zeolite seeds nor the secondary mesoporogen were required. Only a bit amount of organic template (denoted as TEAOH/SiO 2 ratio = 0.06) was used to obtain highly crystalline zeolite Beta, which was remarkably lower than the reported lowest value (0.10). Physicochemical properties of the resulting samples were investigated by comprehensive characterizations including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, solid state 27 Al MAS NMR spectra, nitrogen adsorption–desorption, X-ray fluorescence, temperature-programmed desorption of ammonia and infrared spectra of pyridine adsorption. These characterization results showed that the SAC method led to hierarchical crystalline zeolite Beta aggregates assembled by 20–40 nm nanosized crystals with controllable SiO 2 /Al 2 O 3 ratios among 29–47 by varying the compositions of synthetic gels with the Na 2 O/SiO 2 ratio of 0.12 and the H 2 O/dry gel ratios at 0.20–0.30. These zeolite Beta aggregates possessed large external surface area (158–180 m 2 /g) and mesoporous volume (0.27–0.30 cm 3 /g) resulted from the formation of intercrystalline mesopores and of the small zeolite crystal sizes. The obtained hierarchical zeolite Beta showed 41.2% conversion in the esterification reaction of levulinic acid with ethanol and four catalytic runs without obvious decrease in conversion, which were better than those on the zeolite Beta samples from the conventional hydrothermal synthesis. This was due to the promotion of the accessibility of reactants to the acid sites distributed on the external surface of zeolite nanocrystals and of the prominent diffusion in intercrystalline mesopores. [ABSTRACT FROM AUTHOR]

In the last few years, the research area of chiral β-aminophosphines capable of promoting a wide range of diverse organic transformations has attracted more attention. Their derivatives constitute attractive reagents towards this end, due to their stability, low toxicity and ease of handling. These novel β-aminophosphine derivatives are potentially useful as organocatalysts and ligands in metal-catalysed reactions. In particular, chiral β-aminophosphines have recently emerged as powerful phosphine catalysts in asymmetric synthesis and catalysis. The asymmetric transformations to which metal complexes of these ligands have been applied include palladium-catalysed allylic substitutions and copper-catalysed 1,4-additions to enones among others. This review summarizes the most significant developments in the area of synthesis and application of chiral β-aminophosphine derivatives, providing a detailed overview of the current state of the art and including future aspects. [ABSTRACT FROM AUTHOR]

Metal carbenes, generated from the decomposition of diazo compounds by transition-metals, have a broad range of applications in organic synthesis. The progress of organic transformation via transition metal (such as Rh, Cu, Fe, Ag) carbenes has been well summarized in a few excellent reviews. This review will summarize gold-catalyzed transformations of α-diazocarbonyl compounds by highlighting the specificity and applicability of these diverse transformations such as X–H insertion, C–H functionalization, cyclopropanation, cycloaddition, and coupling reactions. In order to understand these reactions, the mechanistic rationale for selected examples is also provided. [ABSTRACT FROM AUTHOR]

Temperature dependent-electrical resistance of n-type Bi2Te3 was investigated under high pressure. Superconductivity was detected at 4.9 GPa with Tconset = 2.8 K. Resistance and Tc suggest that there are two electronic phase transitions below 10 GPa. We conjecture that the bulk insulating phase first changes to semimetal and then to metal. The evolution of the Hall coefficient is qualitatively consistent with the proposed electronic phase transition. The origin of superconductivity and topological properties are also discussed. [ABSTRACT FROM AUTHOR]

Complexation of cisplatin with a p53 activator as a single anticancer agent resulted in synergistically improved cytotoxicity in p53 wild-type but not p53 null human cancer cells. Mechanistic investigation was carried out on this dual-targeting Pt(iv) prodrug, chalcoplatin. The prodrug effectively entered cancer cells and arrested the cell cycle at the S and G2/M phases, distinctive of that from cisplatin. Chalcoplatin significantly induced p53 activation as well as the subsequent apoptosis pathways. This unique mode of action renders chalcoplatin remarkably cytotoxic and makes this compound among the first examples of a Pt(iv) prodrug that directly interacts with the downstream pathway after the formation of Pt–DNA lesions. [ABSTRACT FROM AUTHOR]

Homogeneous gold-catalyzed cyclopropanation has emerged as a powerful method in organic synthesis due to its rich chemistry and fascinating reactivity. This thriving strategy is remarkable for its mild conditions, good selectivity, and high efficiency, which provides complementarity and orthogonality to traditional metal-catalyzed cyclopropanation. This review summarizes recent advances in gold-catalyzed cyclopropanation divided by the type of carbenoid precursors. Besides the commonly used diazo compounds, current approaches enable readily available enynes, propargyl esters, cyclopropenes, cycloheptatrienes, alkynes, and sulfonium ylides as safer surrogates in the realm of gold carbenoid chemistry. Meanwhile, these reactions allow for the rapid building of molecular complexity including synthetically useful and intricate cyclic, heterocyclic, and polycyclic skeletons. The combination of the new reactivity of gold complexes with their capability to catalyze cyclopropanations may lead to myriad opportunities for the design of new reactions. Furthermore, the synthetic utilities of such superior methods have also been illustrated by the total syntheses of selected natural and biologically interesting products and the asymmetric formation of challenging target molecules. [ABSTRACT FROM AUTHOR]

Angularly fused carbocyclic frameworks and their heteroatom-substituted analogues exist in many natural products that display a broad and interesting range of biological activities. Preparation of polycyclic products by cycloaddition reactions have been the long-standing hot topic in the synthetic community. Dehydro-Diels-Alder (DDA) reactions are one class of dehydropericyclic reactions that are derived conceptually by systematic removal of hydrogen atom pairs. A base-promoted tandem Michael addition and DDA reaction of α,α-dicyanoolefins with electron-deficient 1,3-conjugated enynes was realized in which a DDA reaction takes place between the arylalkynes and electron-deficient tetrasubstituted olefin. The control experiments support the stepwise anionic reaction pathway rather than the concerted reaction pathway. [ABSTRACT FROM AUTHOR]

A phosphine-mediated regio- and stereoselectiveaddition reactionof diverse nucleophiles to yne-enones leading to polysubstituted 1,3-dienescaffolds in moderate to good yields has been reported. [ABSTRACT FROM AUTHOR]

A formal gold(I)-catalyzed diastereoselective [4+3] cycloaddition of oxime ethers with imines, consisting of 1,2-alkyl migration under mild reaction conditions, has been developed; this provides facile access to a series of highly substituted trans-pyrrolo[3,4- c]azepines. This reaction is easily scaled up to the gram scale. [ABSTRACT FROM AUTHOR]

• Al-doped γ-In 2 S 3 nanosheets-composed flowerlike nanostructure was fabricated by a one-step solution-phase avenue. • It displayed a maximal FE HCOO – of 91.2% at −1.0 V with partial current density of 23 mA cm−2. • It exhibited a high EE HCOO – of 58.5% at −1.0 V and kept with a high EE HCOO –> 50% ranged from −0.9 to −1.2 V. • Al3+ ions doping optimized the electronic structure, enhanced the conductivity and exposed more active sites. • Al3+ ions doping decreased the work function and facilitated the fast Faradaic process of CO 2 activation. [Display omitted] It is an urgent imperative to convert CO 2 molecules into valuable chemicals or fuels for mitigating the greenhouse effect and energy dilemma. Herein, γ-In 2 S 3 nanosheets-composed flowerlike nanostructure doped by tunable amount of Al3+ ions was fabricated by a one-step solution-phase avenue for efficient CO 2 ER to formate. The particular nanosheets-composed flowerlike nanostructure exhibited good gas-permeable behavior, enlarging the capacity of CO 2 adsorption and accelerating the mass-transport efficiency. The Al dopant in γ-In 2 S 3 optimized the electronic structure of γ-In 2 S 3 , which enhanced the carrier density, conductivity, and exposed active sites. Besides, Al doping reduced the work function of γ-In 2 S 3 , which brought about the fast Faradaic process of CO 2 activation and speeded up the subsequent reduction reaction. The optimal Al 4.8% -In 2 S 3 displayed the maximal formate Faradaic efficiency (FE HCOO –) of 91.2% at −1.0 V and maintained with a high FE HCOO –> 80% in a potential range of −0.9 to −1.2 V. Moreover, it exhibited a high formate energy efficiency (EE HCOO –) of 58.5% at −1.0 V and kept with a high EE HCOO –> 50% in a potential range of −0.9 to −1.2 V. Besides, Al 4.8% -In 2 S 3 delivered the partial current density of 23 mA cm−2 at −1.0 V for formate and increased to 31.7 mA cm−2 at −1.2 V. It also maintained over 90.8% of FE HCOO – and the current value decayed less than 2% after 14 h continuous electrocatalysis at −1.0 V, exhibiting remarkable operational stability in CO 2 ER. This work optimized electronic structure of metal chalcogenides by heterocations doping toward highly active and selective CO 2 ER to formate and beyond. [ABSTRACT FROM AUTHOR]

In this work, the SnO 2 -CuO composite nanoparticles are fabricated as an ethanol gas sensor by one-step hydrothermal method, which is a core-shell structure composed of tetragonal tin oxide and monoclinic copper oxide. As ethanol gas sensor, the SnO 2 -CuO composite nanoparticles show excellent gas sensitivity and good selectivity to ethanol when deionized water as the hydrothermal solvent and Sn: Cu = 1: 1, and it have a small response recovery time of approximately 4 and 10 s respectively, and response value has a good linear relationship with the ethanol concentration between 50 and 300 ppm. The outstanding gas sensor character of the SnO 2 -CuO composite nanoparticles would be mainly attributed to special heterostructure and synergistic effect between tin oxide and copper oxide. [Display omitted] • A simple hydrothermal method was used to synthesize composite SnO 2 -CuO nanoparticles in one step. • The gas sensor made of composite SnO 2 -CuO has excellent selectivity for ethanol gas. • The response value to 100 ppm ethanol reached 8.0, and its response/recovery time were 4 s and 10 s, respectively. • The response value of the gas sensor has a good linear relationship with the ethanol concentration between 50 and 300 ppm. • The molar ratio of Sn and Cu has a significant impact on gas sensitivity. [ABSTRACT FROM AUTHOR]

• Composite SnO 2 /CuO nanotubes were synthesized by simple electrospinning method. • The gas sensor made of SnO 2 /CuO nanotubes has excellent selectivity for ethanol. • The response value of the gas sensor has a good linear relationship with ethanol concentration in the range of 25–300 ppm. • The response value to 250 ppm ethanol is 8.8, and its response and recovery time are 6 and 10 s, respectively. • The molar ratio of Sn to Cu has an important influence on gas sensing properties of materials. [Display omitted] The composite SnO 2 /CuO nanotubes are prepared by uniaxial electrospinning. By controlling the molar ratio of tin to copper, SnO 2 /CuO nanotubes (F-1, molar ratio 1:1) and nanofibers (F-1, molar ratio 1:2) samples are prepared, respectively. The experimental results show that the composite SnO 2 /CuO nanotubes have excellent selectivity for ethanol, the response to ethanol at the same concentration and temperature is three times that of other gases, the saturated concentration of ethanol gas is 250 ppm and 300 ppm respectively, the optimal working temperature is 340 ℃ and the response value has a good linear relationship with the ethanol concentration between 25 and 300 ppm. The response value of F-1 is higher than that of F-2 in the same concentration of ethanol. The response value of the gas sensor based on F-1 to 250 ppm ethanol reaches 8.8 at 340 ℃, and its response and recovery time are 6 and 10 s respectively. The gas sensing mechanism of the material is explained by using the theory of electron depletion layer and barrier height, which is the basis of our follow-up work. [ABSTRACT FROM AUTHOR]

Flustering oxindoles: An enantioselective synthesis of 3,3′‐disubstituted oxindoles by conjugate addition of malonates to isatylidene‐3‐acetaldehydes in high yield and enantioselectivity is developed (see scheme). The synthetic utility of this reaction is demonstrated by the synthesis of three oxindole core structures and the asymmetric total synthesis of debromoflustramine E. [ABSTRACT FROM AUTHOR]

Golden opportunities: A redox‐, atom‐, and step‐economical asymmetric cascade reaction for the synthesis of chiral spirocyclic architectures with two contiguous stereocenters in high yields and excellent enantioselectivities by using a gold/chiral Brønsted acid relay catalysis system is described (see scheme). The results suggest that the chiral Brønsted acid rather than the chiral gold phosphate complex serves as the real catalyst of the enantiodetermining step. [ABSTRACT FROM AUTHOR]

A novel strategy for the enantioselective synthesis of 3,3′-disubstituted oxindoles by the organocatalytic Michael addition of indoles to isatylidene-3-acetaldehydes was developed, which can be used for the formal total synthesis of (−)-chimonanthine and the core structure construction of (+)-gliocladin C. [ABSTRACT FROM AUTHOR]

An efficient approach for the synthesis of highly substituted pyrrolo[3,4- d][1,2]oxazepines has been achieved by gold(I)-catalyzed 1,3-dipolar cycloaddition reactions of 1-(1-alkynyl)cyclopropyl oximes with nitrones in good to excellent yields as a single diastereomer. A complete chirality transfer was observed in this transformation. [ABSTRACT FROM AUTHOR]

A sol–gel film transformation and spraying approach has been developed to fabricate double-layered PBO nanofiber (PNF) nanocomposite paper nanocomposite paper. The construction of stable double-layered structures and nanofiber networks with extensive hydrogen bonds and coordination bonds led to ultraflexibility and excellent folding endurance of the nanocomposite paper. In addition, the nanocomposite paper possessed high wave-transparent coefficient, super-hydrophobicity, and self-cleaning performances. [Display omitted] Poly(p -phenylene-2,6-benzobisoxazole) nanofiber (PNF) paper is facing unprecedented challenges in enhancing the interaction between the PNFs and improving its hydrophobicity. In this work, a sol–gel film transformation approach was developed to fabricate high-strength PNF paper. Iron ions formed coordination bonds between PNFs to obtain a preforming three-dimensional, interconnective nanofiber network. Subsequently, polytetrafluoroethylene (PTFE) particles were sprayed onto the surface of the paper, followed by thermal treatment to obtain double-layered PTFE-P/PNF nanocomposite paper. The nanocomposite paper presents incredible tensile strength (271.6 MPa, increased by 52.9%), folding endurance, super-hydrophobicity, and self-cleaning performances. Moreover, it exhibits low dielectric constant (2.06) and dielectric loss tangent (0.0133) values. According to the wave-transparent model for a double-layered dielectric established by Maxwell's equations, the wave-transparent coefficients of electromagnetic waves incident from both sides of the paper are 97.6% (PNF side) and 96.0% (PTFE/P(S- co -BCB- co -MMA) side), respectively. The PTFE-P/PNF nanocomposite paper possesses great potential in the fields of wave-transparent applications. [ABSTRACT FROM AUTHOR]

An efficient Y(OTf)3-catalyzed generation of azomethine ylides from donor-acceptor aziridines and their [3+2] cycloaddition with imines was developed. The method provides facile access to multisubstituted imidazolidines, which have been extensively used in organic synthesis. Furthermore, a three-component reaction on a gram scale and an asymmetric variation were also developed in this work. [ABSTRACT FROM AUTHOR]

6-Acetoxy-4-alkenyl arenes undergo regio- and stereoselective intramolecular Friedel–Crafts reaction affording benzocycles in moderate to excellent yields in TFA/HOAc (3:1). It was observed that introduction of alkyls or phenyl group to the allylic acetate moiety facilitates the cyclization reaction. The optically active tricyclic (4bR,8aS)-4b,7,8,8a,9,10-hexahydrophenanthrene skeleton could also be easily obtained in excellent yields. [Copyright &y& Elsevier]

Benzocyclohexane derivatives were prepared highly stereoselectively by the cyclic Friedel–Crafts reaction of 6-acetoxy-4-alkenyl arenes in moderate to excellent yields in TFA/HOAc (3:1). It was observed that the rate of the cyclization as well as the yields of products depend largely on the substituents of the allylic acetate moiety. [Copyright &y& Elsevier]

Bisphenol A dicyanate ester (BADCy) was utilized as the matrix, poly (p -phenylene-2, 6-benzobisoxazole) (PBO) fibers as the reinforcement, and synthesized fluorine-containing linear PBO precursor (pre FLPBO) as the interfacial compatibilizer to prepare PBO fibers/FLPBO- m -BADCy wave-transparent laminated composites. The fluorine groups and PBO-like structures could respectively improve the dielectric properties of BADCy matrix and the interfacial compatibility between the BADCy matrix and PBO fibers. Additionally, the partly interpenetrating network formed between pre FLPBO and BADCy could significantly improve the mechanical properties. PBO fibers/FLPBO- m -BADCy wave-transparent laminated composites with 7 wt% pre FLPBO displayed the optimal comprehensive performances. Dielectric constant (ε) and dielectric loss (tan δ) were respectively 2.90 and 0.0042, and the corresponding theoretical wave-transmittance (| T |2) at 1 MHz was 93.3%, higher than that of PBO fibers/BADCy wave-transparent laminated composites. The minimum percentage of simulated electromagnetic wave-transparent energy (E T (simulation)) of the PBO fibers/FLPBO- m -BADCy (1 mm) wave-transparent laminated composites at 0.3~40 GHz was 87.3%, also better than PBO fibers/BADCy wave-transparent laminated composites (85.9%). The flexural and interlaminar shear strength (ILSS) of PBO fibers/FLPBO- m -BADCy wave-transparent laminated composites were increased from 587.4 and 36.7 MPa to 628.0 and 44.8 MPa, respectively. In addition, the corresponding volume resistivity and breakdown voltage were 2.7 × 1015 Ω·cm and 19.12 kV/mm, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

Poly (p -phenylene-2,6-benzobisoxazole) fibers treated by random copolymer P(S -co -BCB- co -MMA) membrane and UV etching (UV-PBO@P fibers) are performed as reinforcement, bisphenol AF/amantadine modified bisphenol A cyanate ester (AEAF- co- BADCy) resin as polymeric matrix, and the UV-PBO@P fibers/AEAF- co -BADCy wave-transparent laminated composites were then fabricated. When the P(S- co -BCB- co- MMA) membrane thickness is 62.3 nm and the UV etching time is 96 h, UV-PBO@P fibers display the best interfacial compatibility with AEAF- co- BADCy resin, and the corresponding wave-transparent laminated composites present the optimal comprehensive performance. Interlaminar shear strength (ILSS) and flexural strength are 50.2 and 745.6 MPa, 27.4% and 21.6% higher than those (ILSS of 39.4 MPa, flexural strength of 613.3 MPa) of pristine PBO fibers/AEAF-co-BADCy wave-transparent laminated composites, respectively. And the composites possess low complex permittivity and tan δ , corresponding | T |2 in the X band is 88.9–94.2%. High-frequency structural simulation (HFSS) results demonstrate that the radome from the composites displays high |T| 2 of 89.1–93.1% in the X-band, close to the theoretical calculation value. This work provides a certain theoretical guidance for fabricating lightweight, high strength, and high | T |2 polymer matrix wave-transparent composites, and further broadens the application of PBO fibers and cyanate ester resins in aviation/aerospace, 5G communication services, electronic information, and other fields. [Display omitted] • A novel way to improve the interfacial bonding strength between fibers and resins. • The wave transmission performances of composites were investigated. • A certain theoretical guidance for fabricating wave-transparent composites.. [ABSTRACT FROM AUTHOR]

This article predicts bending very high cycle fatigue (VHCF) life of three typical nickel‐based alloys SM2550, BG2532, and G3 used for completion strings. Fatigue tests were conducted on the three alloys using an ultrasonic fatigue system at a frequency of 20 kHz. The results showed that the fatigue strength ranges of the three alloys were markedly different, reflecting their different sensitivities to fatigue loading. Scanning electron microscope observations revealed numerous fatigue crack origins with internal decohesion in the fatigue source region. To achieve unified prediction of the fatigue life for the three alloys, a prediction model based on deep learning was built with inputs including fatigue initiation quantity, cleavage facet size, and other fatigue fracture characteristics. It was found that single source feature was insufficient to obtain satisfactory prediction accuracy for all alloys, while multifeature coupling integration could significantly improve the prediction precision, enabling reliable prediction of alloy fatigue life. This study provides new insights into bending VHCF life prediction. Highlights: This article predicts bending VHCF life for three completion strings.Bending VHCF life model utilizing deep wise separable convolution was established.Deep learning can effectively integrate with bending VHCF analyses. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Atropisomeric anilides are one of important C—N axially chiral compounds. Compared with the N‐terminal functionalization to prepare such compounds, C‐terminal functionalization strategies have been rarely reported. We describe herein an efficient synthesis of axially chiral anilides enabled by Pd‐catalyzed desymmetric Sonogashira cross‐coupling reactions with the use of a newly identified Ming‐Phos. Moderate to high yields with high enantioselectivities (up to 98% ee) were obtained. [ABSTRACT FROM AUTHOR]

A gold(i)-catalyzed tandem oxidation/cyclopropanation reaction of 1,6-enynes with an external oxidant has been developed. This quite simple and rapid strategy will provide a safe, mild and versatile avenue to numerous carbo- and hetero [n.1.0]bicyclic frameworks. [ABSTRACT FROM AUTHOR]

A novel Pd(OAc)2/CuI-cocatalyzed three-component reaction of 2-(1-alkynyl)-2-alken-1-ones, nucleophiles and diaryliodonium salts has been developed. The procedure allows the synthesis of tetrasubstituted furans in good to high yields under mild conditions. [ABSTRACT FROM AUTHOR]

A rhodium-catalyzed domino heterocyclization and formal [(3+2)+2] carbocyclization reaction of readily available diyne-enones and alkynes was developed. [ABSTRACT FROM AUTHOR]

Selective synthesis of ring-fused tetrahydroquinolines and tetrahydroazepines from the same starting materials was achieved by subtle use of the oxophilic Sc(OTf)3or carbophilic IPrAuOTf as the catalyst. [ABSTRACT FROM AUTHOR]

To decrease energy loss in water-alkali electrolysis, it is crucial to construct highly active HER electrocatalyst in alkaline media. In this work, Pt nanoparticles uniformly immobilized on Fe-doped α-Ni(OH) 2 nanosheets array with low Pt loading was designed through one-step liquid-phase route. Impressively, the optimized Pt 2.3% -Fe 0.05 Ni 0.95 (OH) 2 with ∼3.5 nm size of Pt nanoparticles displays superior HER electrocatalytic performance in alkaline electrolyte. It can drive 10 mA cm−2 at very low overpotential of 18 mV, and 500 mA cm−2 of high current density at fairly low overpotential of 159 mV with a small Tafel slope of 25.6 mV dec−1. Its mass activity is 15.23 mA μg Pt −1 at − 0.070 V vs. RHE, almost 28.7 times relative to Pt/C. Moreover, it presents distinguished stability in both low and high current densities. Fe3+ ions doped in α-Ni(OH) 2 lattice by partial substitution of Ni2+ ions provides a good platform for anchoring ultrafine Pt nanoparticles. A synergy between the Fe-doped α-Ni(OH) 2 nanosheets interface for water dissociation and the Pt nanoparticles surface for adsorbed H atoms recombination enhances the catalytic activity for HER. The strong contact between Pt nanoparticles and site-specific Fe3+-O(H)–Pt bonds of Fe-doped α-Ni(OH) 2 nanosheets is contributed to its outstanding activity and stability. Image 1 • Pt nanoparticles/Fe-doped α-Ni(OH) 2 nanosheets array is constructed. • The Pt loading is as low as 2.3%. • It can serve as a high-performance electrocatalyst for alkaline HER. • It can deliver 10 mA cm−2 at a low overpotential of 18 mV. • It can drive 500 mA cm−2 at a low overpotential of 159 mV. [ABSTRACT FROM AUTHOR]