3D carbon superstructures are fabricated through the hierarchical assembly of polyimide nanosheets and thermal treatment. Benefiting from the ultrahigh surface area and the hierarchically porous structure, along with the well-distributed highly electroactive sites, the flower-like carbon material exhibits outstanding catalytic activity toward the oxygen reduction reaction and also serves as a highly stable electrode material in supercapacitors.
rate up to 90%, but below 36% in the case of advanced GC patients. [1a] An effective approach of early GC detection requires the combination of initial pre-selection of high-risk individuals and follow-up endoscopy examination, while its largescale application is facing challenges like low cost-efficiency (e.g., inefficient preselection by non-specific risk factors), poor patient compliance, and shortage of experienced endoscopists, etc. [2b] Therefore, it is pressing to develop a rapid and noninvasive method to discover biomarkers and diagnose early GC with an improved prognosis.Liquid biopsy allows the detection of oncotarget biomarkers through non-invasive techniques from biofluids (e.g., blood), holding promise for early screening of GC in clinics. [4] Various genetic (e.g., circulating tumor DNA (ctDNA)) [5] and protein (e.g., carcino embryonic antigen (CEA)) biomarkers in human blood have been discovered for GC diagnosis, but the applicable performance is limited by suboptimal accuracy (e.g., sensitivity of 13% for CEA), [6] high cost (€140 per test), [7] and lack of validation in early GC patients. [1b,8] Besides genes and proteins, metabolites serve as direct signatures of biochemical activity and are associated with gastric carcinogenesis. [9] Mass spectrometry (MS), particularly laser desorption/ionization (LDI) MS, is a powerful analytical tool capable of the simultaneous detection and spatial mapping of various metabolites. [10] However, it is offset in metabolic profiling with Gastric cancer (GC) is a multifactorial process, accompanied by alterations in metabolic pathways. Non-invasive metabolic profiling facilitates GC diagnosis at early stage leading to an improved prognostic outcome. Herein, mesoporous PdPtAu alloys are designed to characterize the metabolic profiles in human blood. The elemental composition is optimized with heterogeneous surface plasmonic resonance, offering preferred charge transfer for photoinduced desorption/ionization and enhanced photothermal conversion for thermally driven desorption. The surface structure of PdPtAu is further tuned with controlled mesopores, accommodating metabolites only, rather than large interfering compounds. Consequently, the optimized PdPtAu alloy yields direct metabolic fingerprints by laser desorption/ionization mass spectrometry in seconds, consuming 500 nL of native plasma. A distinct metabolic phenotype is revealed for early GC by sparse learning, resulting in precise GC diagnosis with an area under the curve of 0.942. It is envisioned that the plasmonic alloy will open up a new era of minimally invasive blood analysis to improve the surveillance of cancer patients in the clinical setting.
Three series of stable, neutral, π-extended bispentalene derivatives, with two pentalenes fused to a central benzene or naphthalene moiety, have been prepared through a modified double carbopalladation cascade reaction. While these chromophores feature skeletons with [4n+2] π-electron perimeters, the two 8 π-electron pentalene subunits strongly influence bonding and spectral properties. (1)H NMR spectra showed large upfield shifts of the protons in the pentalene moieties, comparable to antiaromatic monobenzopentalenes. Further investigations on magnetic ring currents through NICS-XY-scans suggest a global paratropic current and a local diatropic current at the central benzene ring in two of the series, while the third series, with a central naphthalene ring, showed more localized ring currents, with stronger paratropic ring currents on the pentalene moieties. X-ray diffraction analyses revealed planar bispentalene cores with large double- and single-bond alternation in the pentalene units, characteristic for antiaromaticity, and small alternation in the central aromatic rings. In agreement with TD-DFT calculations, both optical and electrochemical data showed much smaller HOMO-LUMO energy gaps compared to other neutral, acene-like hydrocarbons with the same number of fused rings. Both experimental and computational results suggest that the molecular properties of the presented bispentalenes are dominated by the antiaromatic pentalene-subunits despite the [4n+2] π-electron perimeter of the skeletons.
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