Exclusive Co-N4 Sites Confined in Two-dimensional Metal-Organic Layers Enabling Highly Selective CO2 Electroreduction at Industrial-Level Current

Metal-organic framework catalysts bring new opportunities for CO₂ electrocatalysis. Herein, we first conduct density-functional theory calculations and predict that Co-based porphyrin porous organic layers (Co-PPOLs) exhibit good activity for CO₂ conversion because of the low *CO adsorption energy at Co-N₄ sites, which facilitates *CO desorption and CO formation. Then, we prepare two-dimensional Co-PPOLs with exclusive Co-N₄ sites through a facile surfactant-assisted bottom-up method. The ultrathin feature ensures the exposure of catalytic centers. Together with large specific area, high electrical conductivity and CO₂ adsorption capability, Co-PPOLs achieve a peak faradaic efficiency for CO production (FE_CO=94.2 %) at a moderate potential in CO₂ electroreduction, accompanied with good stability. Moreover, Co-PPOLs reach an industrial-level current above 200 mA in a membrane electrode assembly reactor, and maintain near-unity CO selectivity (FE_CO>90 %) over 20 h in CO₂ electrolysis.     

Fast in-line bottom-up analysis of monoclonal antibodies: Toward an electrophoretic fingerprinting approach

For their characterization and quality control, monoclonal antibodies are frequently analyzed at the bottom-up level to generate specific fingerprints that can be used to tackle post-translational modifications or ensure production consistency between lots. To circumvent time-consuming and labor-intensive off-line sample preparation steps, the implementation of integrated methodologies from sample preparation to separation and detection is highly valuable. In this perspective, capillary zone electrophoresis appears as a choice technique since the capillary can subsequently be used as a vessel for sample preparation and electrophoretic discrimination/detection of the reaction products. Here, a fast in-line methodology for the routine quality control of mAbs at the bottom-up level is reported. Simultaneous denaturation and reduction (pretreatment step) were conducted with RapiGest® surfactant and dithiothreitol before in-line tryptic digestion. Reactant mixing was realized by transverse diffusion of laminar flow profile under controlled temperature. In-line digestion was carried out with a resistant trypsin to autolysis. The main parameters affecting the digestion efficiency (trypsin concentration and incubation conditions) were optimized to generate mAb electrophoretic profiles free from trypsin interferences. An acidic MS-compatible BGE was used to obtain high resolution separation of released peptides and in-line surfactant cleavage. The whole methodology was performed in less than two hours with good repeatability of migration times (RSD = 0.91%, n = 5) and corrected peak areas (RSD = 9.6%, n = 5). CE-fingerprints were successfully established for different mAbs and an antibody-drug conjugate.     

Grouped Functional Time Series Forecasting: An Application to Age-Specific Mortality Rates

Age-specific mortality rates are often disaggregated by different attributes, such as sex, state, and ethnicity. Forecasting age-specific mortality rates at the national and sub-national levels plays an important role in developing social policy. However, independent forecasts at the sub-national levels may not add up to the forecasts at the national level. To address this issue, we consider reconciling forecasts of age-specific mortality rates, extending the methods of Hyndman et al. in 2011 Hyndman, R. J., Ahmed, R. A., Athanasopoulos, G., and Shang, H. L. (2011), “Optimal Combination Forecasts for Hierarchical Time Series,” Computational Statistics and Data Analysis, 55, 2579–2589.[Crossref], [Web of Science ®] , [Google Scholar] to functional time series, where age is considered as a continuum. The grouped functional time series methods are used to produce point forecasts of mortality rates that are aggregated appropriately across different disaggregation factors. For evaluating forecast uncertainty, we propose a bootstrap method for reconciling interval forecasts. Using the regional age-specific mortality rates in Japan, obtained from the Japanese Mortality Database, we investigate the one- to ten-step-ahead point and interval forecast accuracies between the independent and grouped functional time series forecasting methods. The proposed methods are shown to be useful for reconciling forecasts of age-specific mortality rates at the national and sub-national levels. They also enjoy improved forecast accuracy averaged over different disaggregation factors. Supplementary materials for the article are available online.     

Multiplex liquid chromatography-tandem mass spectrometry for the detection of wheat,oat, barley and rye prolamins towards the assessment of gluten-free product safety

Celiac patients should feel confident in the safety of foods labelled or expected to be gluten-free. In this context, a targeted proteomic approach based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) technique was proposed to assess the presence of celiotoxic cereals, namely wheat, oats, barley and rye, in raw and processed food products. To this aim, unique marker peptides were properly selected in order to distinguish between the different cereal types. A revised cocktail solution based on reducing and denaturing agents was exploited for prolamin extraction from raw and processed food; in addition, defatting with hexane was carried out for sample clean-up, allowing to largely reduce problems related to matrix effect. Method validation on fortified rice flour showed good analytical performance in terms of sensitivity (limits of detection in the 2–18 mg kg⁻¹ range). However, poor trueness was calculated for self-made incurred bread (between 3 and 30% depending on the peptide), probably due to baking processes, which reduce gluten extractability. Thus, it is evident that in the case of processed foods further insights into sample treatment efficiency and reference materials for protein calibration are required to obtain accurate gluten determination. Finally, the developed method was applied for the analysis of market food products, offering the possibility to discriminate among cereals, with good agreement with labelled ingredients for gluten-containing foodstuffs.     

Simultaneous Stabilization of Lithium Anode and Cathode using Hyperconjugative Electrolytes for High-voltage Lithium Metal Batteries

Although great progress has been made in new electrolytes for lithium metal batteries (LMBs), the intrinsic relationship between electrolyte composition and cell performance remains unclear due to the lack of valid quantization method. Here, we proposed the concept of negative center of electrostatic potential (NCESP) and Mayer bond order (MBO) to describe solvent capability, which highly relate to solvation structure and oxidation potential, respectively. Based on established principles, the selected electrolyte with 1.7 M LiFSI in methoxytrimethylsilane (MOTMS)/ (trifluoromethyl)trimethylsilane (TFMTMS) shows unique hyperconjugation nature to stabilize both Li anode and high-voltage cathode. The 4.6 V 30 μm Li||4.5 mAh cm⁻² lithium cobalt oxide (LCO) (low N/P ratio of 1.3) cell with our electrolyte shows stable cycling with 91 % capacity retention over 200 cycles. The bottom-up design concept of electrolyte opens up a general strategy for advancing high-voltage LMBs.     

Tetrahedraphene: A Csp3-centered 3D Molecular Nanographene Showing Aggregation-Induced Emission

The bottom-up synthesis of 3D tetrakis(hexa-peri-hexabenzocoronenyl)methane, “tetrahedraphene”, is reported. This molecular nanographene constituted by four hexa-peri-hexabenzocoronene (HBC) units attached to a central sp³ carbon atom, shows a highly symmetric arrangement of the HBC units disposed in the apex of a tetrahedron. The X-ray crystal structure reveals a tetrahedral symmetry of the molecule and the packing in the crystal is achieved mostly by CH⋅⋅⋅π interactions since the interstitial solvent molecules prevent the π⋅⋅⋅π interactions. In solution, tetrahedraphene shows the same electrochemical and photophysical properties as the hexa-^tBu-substituted HBC (^tBu-HBC) molecule. However, upon water addition, it undergoes a fluorescence change in solution and in the precipitated solid, showing an aggregation induced emission (AIE) process, probably derived from the restriction in the rotation and/or vibration of the HBCs. Time-Dependent Density Functional Theory (TDDFT) calculations reveal that upon aggregation, the high energy region of the emission band decreases in intensity, whereas the intensity of the red edge emission signal increases and presents a smoother decay, compared to the non-aggregated molecule. All in all, the excellent correlation between our simulations and the experimental findings allows explaining the colour change observed in the different solutions upon increasing the water fraction.     

Nano-polypyrrole supercapacitor arrays prepared by layer-by-layer assembling method in anodic aluminum oxide templates

A novel method for preparing nano-supercapacitor arrays, in which each nano-supercapacitor consisted of electropolymerized Polypyrrole (PPy) electrode / porous TiO₂ separator / chemical polymerized PPy electrode, was developed in this paper. The nano-supercapacitors were fabricated in the nano array pores of anodic aluminum oxide template using the bottom-up, layer-by-layer synthetic method. The nano-supercapacitor diameter was 80 nm, and length 500 nm. Based on the charge/discharge behavior of nano-supercapacitor arrays, it was found that the PPy/TiO₂/PPy array supercapacitor devices performed typical electrochemical supercapacitor behavior. The method introduced here may find application in manufacturing nano-sized electrochemical power storage devices in the future for their use in the area of microelectronic devices and microelectromechanical systems.     

Metal-organic framework nanosheets and their composites for heterogeneous thermal catalysis: Recent progresses and challenges

Metal-organic framework nanosheets (MONs) as the emerging materials have been attracting great interest because the nanosheets possess a range of fascinating attributes including high surface areas and sufficient accessible active sites, and their nanoscale thicknesses are favorable for mass diffusion and transfer of substrates and products with respect to bulk metal-organic frameworks (MOFs). This review first summarizes the synthetic methods of various MONs from top-down and bottom-up methods as well as their diverse composites with different components. Then, the catalytic applications of MON based nanocatalysts are discussed and the relationships among the composition, structure and catalytic performances are revealed. Finally, the challenges and future outlook about the synthesis of diverse MONs and their composites for heterogeneous catalysis are prospected.     

化学镀技术在超大规模集成电路互连线制造过程的应用

总结自大马士革铜工艺建立以来,电化学工作者利用化学镀技术围绕该工艺而开展的一系列相关研究,介绍了应用化学镀沉积镍三元合金防扩散层和化学镀铜种子层的研究以及离子束沉积法(Ion ized C lus-ter Beam,ICB)形成Pd催化层后的化学镀铜技术和超级化学镀铜方法.简要叙述化学镀铜技术在超大规模集成电路中的应用,总结化学镀铜技术的研究进展,并指出了今后的发展方向.