The past decade has witnessed remarkable success in the synthesis of curved polycyclic aromatics through Scholl reactions which enable oxidative aryl–aryl coupling even in company with the ...introduction of significant steric strain. These curved polycyclic aromatics are not only unique objects of structural organic chemistry in relation to the nature of aromaticity but also play an important role in bottom-up approaches to precise synthesis of nanocarbons of unique topology. Moreover, they have received considerable attention in the fields of supramolecular chemistry and organic functional materials because of their interesting properties and promising applications. Despite the great success of Scholl reactions in synthesis of curved polycyclic aromatics, the outcome of a newly designed substrate in the Scholl reaction still cannot be predicted in a generic and precise manner largely due to limited understanding on the reaction mechanism and possible rearrangement processes. This review provides an overview of Scholl reactions with a focus on their applications in synthesis of curved polycyclic aromatics with interesting structures and properties and aims to shed light on the key factors that affect Scholl reactions in synthesizing sterically strained polycyclic aromatics.
Mass-spectrometry-based proteomic data on human tumors-combined with corresponding multi-omics data-present opportunities for systematic and pan-cancer proteogenomic analyses. Here, we assemble a ...compendium dataset of proteomics data of 2002 primary tumors from 14 cancer types and 17 studies. Protein expression of genes broadly correlates with corresponding mRNA levels or copy number alterations (CNAs) across tumors, but with notable exceptions. Based on unsupervised clustering, tumors separate into 11 distinct proteome-based subtypes spanning multiple tissue-based cancer types. Two subtypes are enriched for brain tumors, one subtype associating with MYC, Wnt, and Hippo pathways and high CNA burden, and another subtype associating with metabolic pathways and low CNA burden. Somatic alteration of genes in a pathway associates with higher pathway activity as inferred by proteome or transcriptome data. A substantial fraction of cancers shows high MYC pathway activity without MYC copy gain but with mutations in genes with noncanonical roles in MYC. Our proteogenomics survey reveals the interplay between genome and proteome across tumor lineages.
•Flower-liked ZnO architectures and Ce doped ZnO materials were successfully synthesized by a simple precipitation route.•Ce doping can improve the sensing performance of ZnO-based gas sensor by ...adjusting the proportion of oxygen species.•0.5 at% Ce/ZnO exhibited the highest response to ethanol and the response value was about 72.6 to 100 ppm ethanol.
Flower-liked ZnO architectures and Ce doped ZnO materials with different amounts (0.2, 0.5, 1.2 and 2 at% Ce) were successfully synthesized by a simple room-temperature precipitation route. As the gas sensing materials, their sensing performance were investigated systematically. The results indicate that Ce doping can improve the performance of ZnO sensor. The ZnO doped with 0.5 at% Ce exhibited the highest response to ethanol at the operating temperature of 300 °C, and the response value was about 72.6–100 ppm ethanol. With Ce doping, the proportions of oxygen vacancy and chemisorbed oxygen species were increased obviously, which could greatly promote the gas sensing properties of surface resistance-type metal oxide semiconductors. Thus, the doping of flower-liked ZnO with Ce should be a promising approach for designing and fabricating the high performance gas sensor.
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•Pd decorated WO3 exhibited ultrafast detection of H2S.•Response to H2S of WO3 sensor increased by 250 times after Pd-decoration.•Mechanism for enhanced sensing performance of Pd ...decorated WO3 was proposed.
Sensors based on pristine and Pd/PdO-loaded WO3 microspheres (NWs) were fabricated for H2S detection. Solvothermal method was employed to synthesize pristine WO3 microspheres. The Pd/PdO decoration procedure was realized by immersing the pristine WO3 into the solution with Pd precursor. Pd/PdO nanoparticles with diameter around 4−7 nm were successfully loaded on the surface of the WO3 microspheres characterized by SEM, TEM, HRTEM, EDS and XPS. Sensing performances were systematically investigated with varying Pd loading amount (0 at%, 1 at%, 2 at%, 5 at%). The sensitively and selectively were significantly improved after loaded with Pd. The 2 at % loaded sensing material exhibited the highest response of 1029 to 25 ppm H2S, which was 270 times higher than the pristine WO3 at 190 °C. Importantly, the sensor showed quite short response time (less than or equal to1 s) after loaded with Pd/PdO. The tremendous gas sensing enhancement could be attributed to the adjustment of the oxygen state, modulation of sensor resistance and catalytic effects of Pd/PdO. This study demonstrated that decorating WO3 with Pd/PdO is an effective route to realize the H2S detection with high response. The fabricated H2S sensor offered potential applications in the fields of rapid detection toward H2S.
An unexpected metal-free CC triple bond cleavage, dioxygen activation, and reassembly into tryptophol derivatives has been developed. This chemistry provides a novel, simple, and efficient approach ...to highly valuable tryptophol derivatives from simple substrates under mild conditions. The mechanistic studies may promote the discovery of new methodologies through C–C bond cleavage and dioxygen activation.
As the leading urban agglomeration in China, the Yangtze River Delta (YRD) is experiencing a factor-driven to innovation-driven transition. However, the dynamics of regional innovation growth are not ...yet fully understood. This paper combines the complex network methodology with spatial econometrics to disentangle the contributions of innovation endowments, innovation network flows, and innovation network positions to regional innovation growth, as well as their spatial spillover effects. The primary findings suggest that regional innovation growth results from the networked agglomeration economies, which is shaped by the interactions between agglomeration factors and network factors. Specifically, agglomeration factors play a fundamental role in regional innovation growth. In contrast, network factors, such as the network flows and network positions, may contribute to new path creation by promoting access to external innovation resources. Additionally, the institutional factors show multiplexity in fostering regional innovation patterns. Such findings indicate that the YRD region should shift the innovation growth pattern from competitive involution to mutually beneficial cooperation to reduce regional disparities. In this regard, the institutional capacity of organizing network flows and fostering reciprocal inter-city partnerships has become increasingly critical for promoting sustainable innovation and regional development.
•Strong radical production diminishes radical delievery efficiency in the bulk solution.•The shortest radical penetration depth appears in the main bubble collapse.•The penetration depth peaks at ...certain acoustic driving pressure.•The excessively intense recombination reactions cause the shortening of penetration depth.
In the sonochemical degradation of nonvolatile compounds, the free radicals must be delivered into the aqueous solution from the cavitation bubble to initiate reduction–oxidation reactions. The penetration depth in the liquid becomes an important parameter that influences the radical delivery efficiency and eventual treatment performance. However, the transport of radicals in the liquid phase is not well understood yet. In this paper, we focus on the most reactive OH radical and numerically simulate its penetration behavior. This is realized by solving the coupled equations of bubble dynamics, intracavity chemistry, and radical dispersion in the aqueous phase. The results present both the local and global penetration patterns for the OH radicals. By performing simulations over a wide range of acoustic parameters, we find an undesirable phenomenon that the penetration can be adversely suppressed when strengthening the radical production. A mechanistic analysis attributes this to the excessively vigorous recombination reactions associated with high radical concentrations near the bubble interface. In this circumstance, the radicals are massively consumed and converted into molecular species before they can appreciably diffuse away. Our study sheds light on the interplay between radical production inside the bubble and dispersion in the outside liquid. The derived conclusions provide guides for sonochemical applications from a new perspective.
An efficient M2CO3-catalyzed (M = K or Cs) aerobic cross dehydrogenative coupling reaction of thiols was described. This reaction provided an efficient approach to unsymmetrical disulfides which are ...ubiquitous structures of pharmaceuticals and pesticides. This is the first aerobic oxidative CDC of thiols to unsymmetrical disulfides. The high atom-economy, easy accessibility of catalyst, O2 as the ideal green oxidant, mild reaction conditions, and broad substrate scope demonstrate that the present methodology provides a green, attractive, and practical approach to disulfides.
Opinion statement
Melanoma is one of the deadliest malignancies. Its incidence has been significantly increasing in most countries in recent decades. Acral melanoma (AM), a peculiar subgroup of ...melanoma occurring on the palms, soles, and nails, is the main subtype of melanoma in people of color and is extremely rare in Caucasians. Although great progress has been made in melanoma treatment in recent years, patients with AM have shown limited benefit from current therapies and thus consequently have worse overall survival rates. Achieving durable therapeutic responses in this high-risk melanoma subtype represents one of the greatest challenges in the field. The frequency of BRAF mutations in AM is much lower than that in cutaneous melanoma, which prevents most AM patients from receiving treatment with BRAF inhibitors. However, AM has more frequent mutations such as KIT and CDK4/6, so targeted therapy may still improve the survival of some AM patients in the future. AM may be less susceptible to immune checkpoint inhibitors because of the poor immunogenicity. Therefore, how to enhance the immune response to the tumor cells may be the key to the application of immune checkpoint inhibitors in advanced AM. Anti-angiogenic drugs, albumin paclitaxel, or interferons are thought to enhance the effectiveness of immune checkpoint inhibitors. Combination therapies based on the backbone of PD-1 are more likely to provide greater clinical benefits. Understanding the molecular landscapes and immune microenvironment of AM will help optimize our combinatory strategies.
This paper presents a fully integrated energy harvester that maintains >35% end-to-end efficiency when harvesting from a 0.84 mm 2 solar cell in low light condition of 260 lux, converting 7 nW input ...power from 250 mV to 4 V. Newly proposed self-oscillating switched-capacitor (SC) DC-DC voltage doublers are cascaded to form a complete harvester, with configurable overall conversion ratio from 9× to 23×. In each voltage doubler, the oscillator is completely internalized within the SC network, eliminating clock generation and level shifting power overheads. A single doubler has >70% measured efficiency across 1 nA to 0.35 mA output current ( >10 5 range) with low idle power consumption of 170 pW. In the harvester, each doubler has independent frequency modulation to maintain its optimum conversion efficiency, enabling optimization of harvester overall conversion efficiency. A leakage-based delay element provides energy-efficient frequency control over a wide range, enabling low idle power consumption and a wide load range with optimum conversion efficiency. The harvester delivers 5 nW-5 μW output power with >40% efficiency and has an idle power consumption 3 nW, in test chip fabricated in 0.18 μm CMOS technology.
