With the integration and miniaturization of electronic devices, thermal management has become a crucial issue that strongly affects their performance, reliability, and lifetime. One of the current ...interests in polymer-based composites is thermal conductive composites that dissipate the thermal energy produced by electronic, optoelectronic, and photonic devices and systems. Ultrahigh thermal conductivity makes graphene the most promising filler for thermal conductive composites. This article reviews the mechanisms of thermal conduction, the recent advances, and the influencing factors on graphene-polymer composites (GPC). In the end, we also discuss the applications of GPC in thermal engineering. This article summarizes the research on graphene-polymer thermal conductive composites in recent years and provides guidance on the preparation of composites with high thermal conductivity.
H2O2 plays an irreplaceable role in many aspects of human society, such as paper bleaching, medical disinfection, wastewater treatment, organic synthesis, hydrometallurgy and the electronic industry. ...However, the unsustainability of the current industrial production process of traditional anthraquinone has a serious conflict with the green sustainable development. The photo/electrocatalytic H2O2 production from renewable energy has the advantages of being more economical, low‐carbon and green, and in line with the requirements of energy economy. These catalytic methods of green H2O2 production have played a demonstrative role in the development of many small molecules, contributing to a fundamental understanding of general catalysis and providing a scientific perspective for future new energy cycles. In this review, the authors aim to integrate the reaction process and mechanism of photocatalytic and electrocatalytic H2O2 production, summarize the development and application of photocatalytic and electrocatalytic H2O2 production in recent years, and assess the modern technologies promoted in the process of H2O2 production research, including the development of flux production equipment and reaction coproduction, etc. This review intends to provide a clear logic profile and new directions for the development of H2O2 production, and calls for more researchers to provide more insights into the development of this field.
This review discusses a versatile photoelectrocatalysis strategy for raising up the green production of hydrogen peroxide with interrogation of reaction principles, engineering the catalytic reaction environment including via sacrificial agents and electrolytes, techniques including transient photoinduced voltage and transient photoinduced current, and reactors.
Linear, α‐branched, and β‐branched aliphatic amines are widespread in pharmaceuticals, agrochemicals, and fine chemicals. Thus, the development of direct and efficient methods to these structures in ...a tunable manner is highly desirable yet challenging. Herein, a catalyst‐controlled synthesis of α‐branched, β‐branched and linear aliphatic amines from Ni/Co‐catalyzed regio‐ and site‐selective hydroalkylations of alkenyl amines with alkyl halides is developed. This catalytic protocol features the reliable prediction and control of the coupling position of alkylation to provide orthogonal access to α‐branched, β‐branched and linear alkyl amines from identical starting materials. This platform unlocks orthogonal reactivity and selectivity of nickel hydride and cobalt hydride chemistry to catalytically repurpose three types of alkyl amines under mild conditions.
A unified protocol for Ni/Co‐catalyzed remote and regiodivergent hydroalkylations of alkenyl amines has been established, providing orthogonal access to α‐branched, β‐branched, and linear aliphatic amines. This catalytic protocol features the reliable prediction and control of the coupling position of alkylation to provide orthogonal access to aliphatic amines with diverse scaffolds from identical starting materials.
General methods for the preparation of geminal bis(boronates) are of great interest due to their widespread applications in organic synthesis. While the terminal gem‐diboron compounds are readily ...accessible, the construction of the sterically encumbered, internal analogues has remained a prominent challenge. Herein, we report a formal umpolung strategy to access these valuable building blocks. The readily available 1,1‐diborylalkanes were first converted into the corresponding α‐halogenated derivatives, which then serve as electrophilic components, undergoing a formal substitution with a diverse array of nucleophiles to form a series of C−C, C−O, C−S, and C−N bonds. This protocol features good tolerance to steric hindrance and a wide variety of functional groups and heterocycles. Notably, this strategy can also be extended to the synthesis of diaryl and terminal gem‐diboron compounds, therefore providing a general approach to various types of geminal bis(boronates).
A general method for accessing sterically encumbered geminal bis(boronates) was developed based on a formal umpolung strategy. The polarity inversion of the readily available 1,1‐diborylalkanes allows their corresponding α‐halogenated derivatives to undergo a formal substitution with a wide variety of nucleophiles to form C−C, C−O, C−S, and C−N bonds, featuring excellent tolerance to steric hindrance and functional groups.
An efficient and selective Cu catalyst for CO2 electroreduction is highly desirable since current catalysts suffer from poor selectivity towards a series of products, such as alkenes, alcohols, and ...carboxylic acids. Here, we used copper(ii) paddle wheel cluster-based porphyrinic metal–organic framework (MOF) nanosheets for electrocatalytic CO2 reduction and compared them with CuO, Cu2O, Cu, a porphyrin–Cu(ii) complex and a CuO/complex composite. Among them, the cathodized Cu-MOF nanosheets exhibit significant activity for formate production with a faradaic efficiency (FE) of 68.4% at a potential of −1.55 V versus Ag/Ag+. Moreover, the C–C coupling product acetate is generated from the same catalyst together with formate at a wide voltage range of −1.40 V to −1.65 V with the total liquid product FE from 38.8% to 85.2%. High selectivity and activity are closely related to the cathodized restructuring of Cu-MOF nanosheets. With the combination of X-ray diffraction, X-ray photoelectron spectroscopy, high resolution transmission electron microscopy and Fourier transform infrared spectroscopy, we find that Cu(ii) carboxylate nodes possibly change to CuO, Cu2O and Cu4O3, which significantly catalyze CO2 to formate and acetate with synergistic enhancement from the porphyrin–Cu(ii) complex. This intriguing phenomenon provides a new opportunity for the rational design of high-performance Cu catalysts from pre-designed MOFs.
Abstract
The oxidized platinum (Pt) can exhibit better electrocatalytic activity than metallic Pt
0
in the hydrogen evolution reaction (HER), which has aroused great interest in exploring the role of ...oxygen in Pt-based catalysts. Herein, we select two structurally well-defined polyoxometalates Na
5
H
3
Pt
(IV)
W
6
O
24
(PtW
6
O
24
) and Na
3
K
5
Pt
(II)
2
(W
5
O
18
)
2
(Pt
2
(W
5
O
18
)
2
) as the platinum oxide model to investigate the HER performance. Electrocatalytic experiments show the mass activities of PtW
6
O
24
/C and Pt
2
(W
5
O
18
)
2
/C are 20.175 A mg
−1
and 10.976 A mg
−1
at 77 mV, respectively, which are better than that of commercial 20% Pt/C (0.398 A mg
−1
). The in situ synchrotron radiation experiments and DFT calculations suggest that the elongated Pt-O bond acts as the active site during the HER process, which can accelerate the coupling of proton and electron and the rapid release of H
2
. This work complements the knowledge boundary of Pt-based electrocatalytic HER, and suggests another way to update the state-of-the-art electrocatalyst.
In this paper, a low parasitic inductance SiC power module with double-sided cooling is designed and compared with a baseline double-sided cooled module. With the unique 3D layout utilizing vertical ...interconnection, the power loop inductance is effectively reduced without sacrificing the thermal performance. Both simulations and experiments are carried out to validate the design. Q3D simulation results show a power loop inductance of 1.63 nH, verified by the experiment, indicating more than 60% reduction of power loop inductance compared with the baseline module. With 0Ω external gate resistance turn-off at 600V, the voltage overshoot is less than 9% of the bus voltage at a load of 44.6A.
COVID-19 pandemic has caused widespread panic and fear among the global population. As such, repurposing drugs are being used as viable therapeutic options due to the limited effective treatments for ...Long COVID symptoms. Ivermectin is one of the emerging repurposed drugs that has been shown effective to have antiviral effects in clinical trials. In addition, antioxidant compounds are also gaining attention due to their capabilities of reducing inflammation and severity of symptoms. Due to the absence of knowledge in pharmacogenomics and modes of actions in the human body for these compounds, this study aims to provide a pharmacogenomic profile for the combination of ivermectin and six selected antioxidants (epigallocatechin gallate (EGCG), curcumin, sesamin, anthocyanins, quercetin, and N-acetylcysteine (NAC)) as potentially effective regimens for long COVID symptoms. Results showed that there were 12 interacting genes found among the ivermectin, 6 antioxidants, and COVID-19. For network pharmacology, the 12 common interacting genes/proteins had the highest associations with Pertussis pathway, AGE-RAGE signaling pathway in diabetic complications, and colorectal cancer in the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Disease analyses also revealed that the top three relevant diseases with COVID-19 infections were diabetes mellitus, ischemia, reperfusion injury. We also identified 6 potential target microRNAs (miRNAs) of the 12 commonly curated genes used as molecular biomarkers for COVID-19 treatments. The established pharmacogenomic network, disease analyses, and identified miRNAs could facilitate developments of effective regimens for chronic sequelae of COVID-19 especially in this post-pandemic era. However, further studies and clinical trials are needed to substantiate the effectiveness and dosages for COVID-19 treatments.
Ferroptosis is a new form of regulated cell death that shows promise for tumor treatment. Most current ferroptosis tumor therapies are based on the intrinsic pathological features of the ...malignancies, and it would be of clinical significance to develop ferroptosis‐inducing strategies with improved tumor specificity and modulability. Here we report a polydopamine‐based nanoplatform (FeIIPDA@LAP‐PEG‐cRGD) for the efficient loading of Fe2+ and β‐lapachone (LAP), which could readily initiate ferroptosis in tumor cells upon treatment with near‐infrared light. PDA nanostructures could generate mild hyperthermia under NIR irritation and trigger the release of the ferroptosis‐inducing Fe2+ ions. The NIR‐actuated photothermal effect would also activate cellular heat shock response and upregulate the downstream NQO1 via HSP70/NQO1 axis to facilitate bioreduction of the concurrently released β‐lapachone and enhance intracellular H2O2 formation to promote the Fe2+‐mediated lipid peroxidation.
Ferroptosis is a new form of regulated cell death and holds promise for tumor inhibition. However, it is difficult to remotely control the initiation and execution of ferroptosis in specific sites. This study reports a biocompatible and biodegradable biopolymeric nanoplatform for tumor‐targeted ferroptosis therapy, of which the pro‐ferroptotic activities could be activated in an on‐demand manner using near‐infrared light as the triggering signal.
Microcystins (MCs) classified as hepatotoxic and carcinogenic are the most commonly reported cyanobacterial toxins found in the environment.
sp. possessing a series of MC synthesis genes (mcyA-mcyJ) ...are well documented for their excessive abundance, numerous bloom occurrences and MC producing capacity. About 246 variants of MC which exert severe animal and human health hazards through the inhibition of protein phosphatases (PP1 and PP2A) have been characterized. To minimize and prevent MC health consequences, the World Health Organization proposed 1 µg/L MC guidelines for safe drinking water quality. Further the utilization of bacteria that represent a promising biological treatment approach to degrade and remove MC from water bodies without harming the environment has gained global attention. Thus the present review described toxic effects and bacterial degradation of MCs.
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