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Nitrogen substitution in nickel nanoparticles leads to lattice contraction promoting hydrogen evolution activity for simulated seawater.

Background: Cerebral hyperperfusion syndrome (CHS) is a failure of autoregulation after a revascularization procedure. It has rarely been reported in patients with no pre-existing cerebral hypoperfusion. Case Report: We present a rare case of a patient who underwent stent graft implantation to treat postirradiated carotid blowout syndrome. The patient developed hypertension, focal neurological deficit, and seizures after the procedure; neuroimages revealed ipsilateral cerebral edema, swelling, and increased cerebral perfusion. CHS was diagnosed based on clinical and radiological findings. The patient recovered gradually after receiving supportive care. Conclusion: Owing to the risk of CHS, monitoring for cerebral perfusion and prevention of hypertension is suggested for patients who undergo stent graft placement for postirradiated carotid blowout syndrome.

The design, materials, process, and fabrication of a hybrid substrate for the heterogeneous integration of chips with 50μm-pitch (minimum) by fan-out chip-last panel-level packaging are presented. The hybrid substrate consists of a fine metal linewidth (L), spacing (S), and thickness (H) RDL (redistribution-layer) substrate, solder joints with underfill, and a build-up package substrate. The dielectric material for the fine metal L/S/H RDL-substrate is an Ajinomoto build-up film (ABF).

Electrochemistry and X-ray absorption spectroscopy (XAS) of MnO2/reduced graphene oxide (RGO) were made to evaluate capacitive performance and electronic structure as a supercapacitor. MnO2 was deposited on the surface of RGO by a spontaneous redox reaction. At low current density (1 A g−1), the specific capacitance of MnO2/RGO (MRGO) greatly increased with increasing growth time from 281 to 462 F g−1. Electrochemical results show that the specific capacitance of RGO and MRGO arises from the combined contributions of electrochemical double-layer capacitance (EDLC) and pseudo-capacitance. To gain insights into the charge storage mechanism of RGO and MRGO, it was characterized using ex-situ soft XAS techniques at Mn L-edge and C, O K-edges in the charging/discharging process. The ex-situ soft XAS results provide evidence that the contribution of RGO to specific capacitance involves an oxygen-functionality-related contribution of pseudocapacitance and EDLC. In addition, the specific capacitance of MRGO reveals pseudocapacitive contributions from the redox processes that involve the Mn(III)/Mn(IV) redox reaction in MnO2. This work utilizes electrochemical and ex-situ XAS techniques to elucidate charge storage mechanism for supercapacitor applications.

Carbon nitride-based photocatalysts hold an enormous potential in producing hydrogen. A strategy to simultaneously create isotype heterojunctions and active sites in highly-crystallized carbon nitride is anticipated to significantly boost the photocatalytic activity, but is yet to be realized. Herein, we find that cobalt salt added in the ionothermal synthesis can promote the phase transition of heptazine-based crystalline carbon nitride (CCN) to triazine-based poly(triazine imide) (PTI), rendering the creation of single-atom cobalt coordinated isotype CCN/PTI heterojunction. Co-CCN/PTI exhibits an appreciable apparent quantum yield of 20.88% at 425 nm for photocatalytic hydrogen production with a rate achieving 3538 μmol h−1 g−1 (λ > 420 nm), which is 4.8 times that of CCN and 27.6 times that of PTI. The high photocatalytic activity is attributed to the Type II isotype highly-crystallized CCN/PTI heterojunction for promoting charge carrier migration, and the single-atom Co sites for accelerating surface oxidation reaction.

Designing efficient catalyst for the oxygen evolution reaction (OER) is of importance for energy conversion devices. The anionic redox allows formation of O-O bonds and offers higher OER activity than the conventional metal sites. Here, we successfully prepare LiNiO2 with a dominant 3d8L configuration (L is a hole at O 2p) under high oxygen pressure, and achieve a double ligand holes 3d8L2 under OER since one electron removal occurs at O 2p orbitals for NiIII oxides. LiNiO2 exhibits super-efficient OER activity among LiMO2, RMO3 (M = transition metal, R = rare earth) and other unary 3d catalysts. Multiple in situ/operando spectroscopies reveal NiIII→NiIV transition together with Li-removal during OER. Our theory indicates that NiIV (3d8L2) leads to direct O-O coupling between lattice oxygen and *O intermediates accelerating the OER activity. These findings highlight a new way to design the lattice oxygen redox with enough ligand holes created in OER process.

Aqueous organic electrosynthesis such as nucleophile oxidation reaction (NOR) is an economical and green approach. However, its development has been hindered by the inadequate understanding of the synergy between the electrochemical and non-electrochemical steps. In this study, we unravel the NOR mechanism for the primary alcohol/vicinal diol electrooxidation on NiO. Thereinto, the electrochemical step is the generation of Ni3+-(OH)ads, and the spontaneous reaction between Ni3+-(OH)ads and nucleophiles is an electrocatalyst-induced non-electrochemical step. We identify that two electrophilic oxygen-mediated mechanisms (EOMs), EOM involving hydrogen atom transfer (HAT) and EOM involving C-C bond cleavage, play pivotal roles in the electrooxidation of primary alcohol to carboxylic acid and the electrooxidation of vicinal diol to carboxylic acid and formic acid, respectively. Based on these findings, we establish a unified NOR mechanism for alcohol electrooxidation and deepen the understanding of the synergy between the electrochemical and non-electrochemical steps during NOR, which can guide the sustainable electrochemical synthesis of organic chemicals.

Cephaleuros species cause algal spot diseases, also known as red rust diseases, on many plants, including fruit crops. Most algal species are defined based on their morphological characteristics. Recent phylogenetic studies of Cephaleuros species showed that morphological determination was not congruent with phylogeny. Our study examined the phylogenetic congruence of the host invasion types (or growth habits), the most critical characteristics in the taxonomy of Cephaleuros. To ensure that host invasion types and phylogenetic characteristics could be inferred from the same isolate, host invasion types were assessed using microanatomical observation, and rRNA sequences from the same algal spot and/or the derived algal cultures were compared. Host invasion types were found to be conserved classification traits and congruent with Cephaleuros phylogeny. The results also indicated that more than one Cephaleuros species commonly grew on the same leaf or, in a few cases, the same algal spot, suggesting that identification using different algal spots could result in misidentification. The Cephaleuros isolates were separated into two species complexes by host invasion types: the Cephaleuros virescens species complex (CVSC) with subcuticular host invasion type and the Cephaleuros parasiticus species complex (CPSC) with intercellular host invasion type. Molecular phylogenetic analysis indicated that Cephaleuros isolates clustered into 14 clades of CVSC and three clades of CPSC. This study also identified 16 and eight new hosts of CVSC and CPSC in Taiwan, respectively.

The production of ecologically compatible fuels by electrochemical water splitting is highly desirable for modern industry. The Zhang-Rice singlet is well known for the superconductivity of high-temperature superconductors cuprate, but is rarely known for an electrochemical catalyst. Herein, we observe two steps of surface reconstruction from initial catalytic inactive Cu1+ in hydrogen treated Cu2O to Cu2+ state and further to catalytic active Zhang-Rice singlet state during the oxygen evolution reaction for water splitting. The hydrogen treated Cu2O catalyst exhibits a superior catalytic activity and stability for water splitting and is an efficient rival of other 3d-transition-metal catalysts. Multiple operando spectroscopies indicate that Zhang-Rice singlet is real active species, since it appears only under oxygen evolution reaction condition. This work provides an insight in developing an electrochemical catalyst from catalytically inactive materials and improves understanding of the mechanism of a Cu-based catalyst for water oxidation.

A kind of graphitic carbon nitride (TSC−550) with high polymerization degree and improved surface property was prepared by a new precursor of thiosemicarbazide. The sulfur motif and high nitrogen content in thiosemicarbazide promoted the polymerization of thiosemicarbazide to form graphitic carbon nitride framework with high degree of polymerization, which significantly influenced the electronic structure and surface chemical properties. TSC−550 possessed a narrow bandgap of 2.19 eV that facilitated the utilization of visible light, and possessed a less positive charge, acidic surface that resulted in enhanced hydrogen adsorption ability in water solution, which promoted the H2 evolution kinetics. In addition, the extended π-conjugated electronic system promoted the separation and migration of photo-generated charge carries in plane of TSC−550 framework, as well as the increasing interlayer C–N interactions in TSC−550 created conductive paths across the layers to tunnel interlayers for rapid electron transportation. As a result, TSC−550 nanosheets showed excellent photocatalytic H2 production activity, the AQY achieved 36.4% at 425 nm.

Electronic structure modulation among multiple metal sites is key to the design of efficient catalysts. Most studies have focused on regulating 3d transition-metal active ions through other d-block metals, while few have utilized f-block metals. Herein, we report a new class of catalyst, namely, UCoO4 with alternative CoO6 and 5f-related UO6 octahedra, as a unique example of a 5f-covalent compound that exhibits enhanced electrocatalytic oxygen evolution reaction (OER) activity because of the presence of the U 5f–O 2p–Co 3d network. UCoO4 exhibits a low overpotential of 250 mV at 10 mA cm–2, surpassing other unitary cobalt-based catalysts ever reported. X-ray absorption spectroscopy revealed that the Co2+ ion in pristine UCoO4 was converted to high-valence Co3+/4+, while U6+ remained unchanged during the OER, indicating that only Co was the active site. Density functional theory calculations demonstrated that the OER activity of Co3+/4+ was synergistically enhanced by the covalent bonding of U6+-5f in the U 5f–O 2p–Co 3d network. This study opens new avenues for the realization of electronic structure manipulation via unique 5f involvement.

Despite of suitable band structures for harvesting solar light and driving water redox reactions, polymeric carbon nitride (PCN) has suffered from poor charge transfer ability and sluggish surface reaction kinetics, which limit its photocatalytic activity for water splitting. Herein, atomically dispersed Zn-coordinated three-dimensional (3D) sponge-like PCN (Zn-PCN) is synthesized through a novel intermediate coordination strategy. Advanced characterizations and theoretical calculations well evidence that Zn single atoms are coordinated and stabilized on PCN in the form of Zn-N6 configuration featured with an electron-deficient state. Such an electronic configuration has been demonstrated contributive to promoted electron excitation, accelerated charge separation and transfer as well as reduced water redox barriers. Further benefited from the abundant surface active sites derived from the 3D porous structure, Zn-PCN realizes visible-light photocatalysis for overall water splitting with H2 and O2 simultaneously evolved at a stoichiometric ratio of 2:1. This work brings new insights into the design of novel single-atom photocatalysts by deepening the understanding of electronic configurations and reactive sites favorable to excellent photocatalysis for water splitting and related solar energy conversion reactions. "Image missing"

To solve surface carrier recombination and sluggish water oxidation kinetics of hematite (α-Fe

Electro-oxidation of 5-hydroxymethylfurfural (HMFOR) is a promising green approach to realize the conversion of biomass into value-added chemicals. However, considering the complexity of the molecular structure of HMF, an in-depth understanding of the electrocatalytic behavior of HMFOR has rarely been investigated. Herein, the electrocatalytic mechanism of HMFOR on nickel nitride (Ni3N) is elucidated by operando X-ray absorption spectroscopy (XAS), in situ Raman, quasi in situ X-ray photoelectron spectroscopy (XPS), and operando electrochemical impedance spectroscopy (EIS), respectively. The activity origin is proved to be Ni2+δN(OH)ads generated by the adsorbed hydroxyl group. Moreover, HMFOR on Ni3N relates to a two-step reaction: Initially, the applied potential drives Ni atoms to lose electrons and adsorb OH− after 1.35 VRHE, giving rise to Ni2+δN(OH)ads with the electrophilic oxygen; then Ni2+δN(OH)ads seizes protons and electrons from HMF and leaves as H2O spontaneously. Furthermore, the high electrolyte alkalinity favors the HMFOR process due to the increased active species (Ni2+δN(OH)ads) and the enhanced adsorption of HMF on the Ni3N surface. This work could provide an in-depth understanding of the electrocatalytic mechanism of HMFOR on Ni3N and demonstrate the alkalinity effect of the electrolyte on the electrocatalytic performance of HMFOR.

In this study, the reliability of chiplets heterogeneous integration on a 2.3D hybrid substrate using solder joint and underfill is investigated. Emphasis is placed on the thermal cycling test and drop test of the structure. The test results are plotted into Weibull distributions, where the Weibull slope and characteristic life at median rank are presented. At 90% confidence, the true Weibull slope interval and the true characteristic life interval are also provided. A linear acceleration factor is adopted to map the solder joint reliability at test condition to the solder joint reliability at an operating condition. The failure location and failure mode of the chip/package assembly of the heterogeneous integration package are provided and discussed.

The panel-level redistribution-layer (RDL)-first fan-out packaging for hybrid substrate is studied. Emphasis is placed on the process, materials, design, and fabrication of: 1) heterogeneous integration of one large chip and one small chip with 50- $\mu \text{m}$ pitch (minimum); 2) fine metal linewidth and spacing RDL-first substrate on a temporary panel carrier; 3) ordinary build-up package substrate on a panel; 4) hybrid substrate which is by soldering the RDL-first substrate on the build-up substrate; and 5) chips to hybrid substrate bonding and underfilling. Reliability assessment by thermomechanical simulation includes thermal cycling of the heterogeneous integration of the two-chip package on the hybrid substrate that is performed by a nonlinear temperature- and time-dependent finite-element analysis.

Bismuth vanadate (BiVO4) has attracted substantial attention on account of its usefulness in producing hydrogen by photoelectrochemical (PEC) water splitting. The exploitation of BiVO4 for this purpose is yet limited by severe charge recombination in the bulk of BiVO4, which is caused by the short diffusion length of the photoexcited charge carriers and inefficient charge separation. Enormous effort has been made to improve the photocurrent density and solar-to-hydrogen conversion efficiency of BiVO4. This study demonstrates that modulating the composition of the electrode and the electronic configuration of BiVO4 by decoration with silver nanoparticles (Ag NPs) is effective in not only enhancing the charge carrier concentration but also suppressing charge recombination in the solar water splitting process. Decoration with a small number of Ag NPs significantly enhances the photocurrent density of BiVO4 to an extent that increases with the concentration of the Ag NPs. At 0.5% Ag NPs, the photocurrent density approaches 4.1 mA cm−2 at 1.23 V versus a reversible hydrogen electrode (RHE) under solar simulated light illumination; this value is much higher than the 2.3 mA cm−2 of pure BiVO4 under the same conditions. X-ray absorption spectroscopy (XAS) is utilized to investigate the electronic structure of pure BiVO4 and its modification by decoration with Ag NPs. Analytical results indicate that increased distortion of the VO4 tetrahedra alters the V 3d–O 2p hybridized states. Additionally, as the Ag concentration increases, the oxygen vacancy defects that act as recombination centers in BiVO4 are reduced. In situ XAS, which is conducted under dark and solar illumination conditions, reveals that the significantly enhanced PEC performance is attributable to the synergy of modulated atomic/electronic structures and the localized surface plasmon resonance effect of the Ag nanoparticles.

Bismuth vanadate (BiVO

BackgroundWe aimed to investigate the interaction between serum uric acid levels with estimated glomerular filtration rate (eGFR) to low muscle strength (LMS) in a large Chinese elderly population.MethodsCohort data were obtained from China Health and Retirement Longitudinal Study (CHARLS) in 2011 and 2015. Two thousand seven hundred forty-five community-dwelling older participants were enrolled for the follow-up. Serum uric acid was collected after 8 hours of fasting, and handgrip strength was measured with a dynamometer. eGFR was calculated with an equation based on the Chinese population. A generalized additive model was employed for interaction analysis and progressively adjusted confounders.ResultsIn this study, we found that men with a low eGFR (2) reported higher SUA levels (5.91 ± 1.27) and older (72.53 ± 6.38) than those who had a high eGFR while women share the same difference with a lower eGFR in higher SUA levels (5.00 ± 1.34) and older (72.81 ± 6.83). After progressively adjusting covariates, in females, the OR for higher eGFR with higher SUA level remained significantly with low muscle strength (OR=0.80 95%CI=0.68-0.95 P=0.0102). This correlation, however, was not observed in men.ConclusionsThis population-based cohort study in Chinese revealed that high serum uric acid level with higher eGFR seems to be significantly associated with a lower risk of low muscle strength in the elderly, especially in females.

This letter presents a second‐order incremental ADC (IADC) operated in three steps, which extends the performance of a second‐order IADC close to that of a fourth‐order IADC with only two amplifiers. It performs a second‐order noise‐shaping quantization in the first step operation. Reusing the same hardware, the circuit is reconfigured to perform fine quantization as a first‐order IADC in the second and third step. Within a conversion time of 60 clock periods (oversampling ratio OSR = 60), 35 dB signal‐to‐quantization‐noise ratio is boosted. The proposed topology is very suitable for low‐bandwidth high‐resolution data conversion.

This work describes a hybrid incremental ADC (IADC) with two-capacitor (2-C) successive-approximation registers (SAR) extended counting in two-step operation to achieve high resolution data conversion. The circuits in the first step is acting as a first-order incremental analog-to-digital converter (IADC). Finite impulse response (FIR) DAC is incorporated in the loop filter to reduce the transient voltage step. It is reconfigured as a 2-C SAR to perform extended counting technique in the second step. Only one opamp is re-used in both steps. The hardware is prototyped in $0.18~\mu \text{m}$ CMOS technology, and the hybrid ADC accomplishes a measured DR / SNR / SNDR of 100.2 / 97.1 / 96.6 dB and an input signal bandwidth of 1.2 kHz. Operated at 1.5-V, it consumes $33.2~\mu \text{W}$ , and this achieves a Walden figure-of-merit (FoM) of 0.25 pJ/conversion-step and Schreier FoM of 175.8 dB.

High-entropy alloys (HEAs) have been widely studied due to their unconventional compositions and unique physicochemical properties for various applications. Herein, for the first time, we propose a surface strain strategy to tune the electrocatalytic activity of HEAs for methanol oxidation reaction (MOR). High-resolution aberration-corrected scanning transmission electron microscopy (STEM) and elemental mapping demonstrate both uniform atomic dispersion and the formation of a face-centered cubic (FCC) crystalline structure in PtFeCoNiCu HEAs. The HEAs obtained by heat treatment at 700°C (HEA-700) exhibit 0.94% compressive strain compared with that obtained at 400°C (HEA-400). As expected, the specific activity and mass activity of HEA-700 is higher than that of HEA-400 and most of the state-of-the-art catalysts. The enhanced MOR activity can be attributed to a shorter Pt-Pt bond distance in HEA-700 resulting from compressive strain. The nonprecious metal atoms in the core could generate compressive strain and down shift d-band centers via electron transfer to surface Pt layer. This work presents a new perspective for the design of high-performance HEAs electrocatalysts.

Photocatalytic overall water splitting can be achieved using Z-scheme systems that mimic natural photosynthesis by combining dissimilar semiconductors in series. However, coupling well-suited H2- and O2-evolving components remains challenging. Here, we fabricate a Z-scheme system for photocatalytic overall water splitting based on boron-doped, nitrogen-deficient carbon nitride two-dimensional (2D) nanosheets. We prepare ultrathin carbon nitride nanosheets with varying levels of boron dopants and nitrogen defects, which leads to nanosheets that can act as either H2- or O2-evolving photocatalysts. Using an electrostatic self-assembly strategy, the nanosheets are coupled to obtain a 2D/2D polymeric heterostructure. Owing to their ultrathin nanostructures, strong interfacial interaction and staggered band alignment, a Z-scheme route for efficient charge-carrier separation and transfer is realized. The obtained heterostructure achieves stoichiometric H2 and O2 evolution in the presence of Pt and Co(OH)2 co-catalysts, and the solar-to-hydrogen efficiency reaches 1.16% under one-sun illumination. Splitting water using suspensions of particulate carbon nitride-based photocatalysts may be a cheap way to produce hydrogen, but efficiencies have remained low. Now, Shen and colleagues use doped carbon nitride-based Z-scheme heterostructures to split water with a solar-to-hydrogen efficiency of 1.1% in the presence of metal-based co-catalysts.

Modulation of bimetallic nanocatalysts with atomic precision would allow for significant increases in catalyst activity through the optimization of heteroatomic interplay. In practice, this level o...

Despite of suitable band structures for harvesting solar light and driving water redox reactions, polymeric carbon nitride (PCN) has suffered from poor charge transfer ability and sluggish surface reaction kinetics, which limit its photocatalytic activity for water splitting. Herein, atomically dispersed Zn-coordinated three-dimensional (3D) sponge-like PCN (Zn-PCN) is synthesized through a novel intermediate coordination strategy. Advanced characterizations and theoretical calculations well evidence that Zn single atoms are coordinated and stabilized on PCN in the form of Zn-N

Preoperative embolization (PE) for metastatic spinal tumors is a method of minimizing intraoperative blood loss during aggressive surgery. This study specified angiographic standards and investigated the influence of these and other factors on blood loss in patients with spinal metastases and various pathologies.The cohort comprised 126 consecutive patients receiving PE from 2015 to 2021. Their clinical, surgical, and angiographic characteristics were reviewed. Standard angiographic grading was used for vascularity assessment. Degree of embolization was divided into complete (≥ 90%), near complete (67 to90%), and partial (67%). Logistic regression analysis was used to investigate factors predictive of massive blood loss (2500 mL). A proportional odds model was used to assess factors predictive of the degree of embolization.Mean intraoperative blood loss was 1676 mL. Among the patients, 62 had hypervascular tumors and 64 had nonhypervascular tumors, according to the angiographic classification. Intraoperative blood loss differed significantly with embolization degree, both overall (p0.001) and in the hypervascular and nonhypervascular groups (p = 0.01 and 0.03). Angiographic hypervascularity, spinal metastasis invasiveness index, and embolization degree were significant predictors of massive blood loss in univariate analysis, but only embolization degree was significant in multivariate analysis. Only the presence of the radiculomedullary artery at the target level was significant in both the univariate and multivariate analyses for embolization degree.In addition to pathological classification, angiographic vascularity assessment is valuable. Although complete embolization is a reasonable goal, it is challenging to achieve in cases of visible radiculomedullary artery.• Angiography has a supplementary role in vascularity assessment for spinal metastatic surgery. • Better embolization degree is associated with less intraoperative blood loss in both angiographic hypervascular and nonhypervascular groups. • Presence of radiculomedullary artery in the target level causes worse embolization outcome.