•High-entropy rare-earth zirconate ceramics demonstrated extreme resistance to CMAS corrosion.•There are no horizontal and vertical cracks in the ceramic substrate and the reaction layer of the HEZ ...sample respectively.•The HEZ suffered from CMAS corrosion only through dissolution and re-precipitation, while additional grain boundary corrosion existed in the LZ.
The corrosion resistance to calcium-magnesium-alumino-silicates (CMAS) is critically important for the thermal barrier coatings (TBCs). High-entropy zirconate (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 (HEZ) ceramics with low thermal conductivity, high coefficient of thermal expansion and good durability to thermal shock is expected to be a good candidate for the next-generation TBCs. In this work, the CMAS corrosion of HEZ at 1300°C was firstly investigated and compared with the well-studied La2Zr2O7 (LZ). It is found that the HEZ ceramics showed a graceful behavior to CMAS corrosion, obviously much better than the LZ ceramics. The HEZ suffered from CMAS corrosion only through dissolution and re-precipitation, while additional grain boundary corrosion existed in the LZ system. The precipitated high-entropy apatite showed fine-grained structure, resulting in a reaction layer without cracks. This study reveals that HEZ is a promising candidate for TBCs with extreme resistance to CMAS corrosion.
The introduction of oxygen vacancies (Ov) has been regarded as an effective method to enhance the catalytic performance of photoanodes in oxygen evolution reaction (OER). However, their stability ...under highly oxidizing environment is questionable but was rarely studied. Herein, NiFe‐metal–organic framework (NiFe‐MOFs) was conformally coated on oxygen‐vacancy‐rich BiVO4 (Ov‐BiVO4) as the protective layer and cocatalyst, forming a core–shell structure with caffeic acid as bridging agent. The as‐synthesized Ov‐BiVO4@NiFe‐MOFs exhibits enhanced stability and a remarkable photocurrent density of 5.3±0.15 mA cm−2 at 1.23 V (vs. RHE). The reduced coordination number of Ni(Fe)‐O and elevated valence state of Ni(Fe) in NiFe‐MOFs layer greatly bolster OER, and the shifting of oxygen evolution sites from Ov‐BiVO4 to NiFe‐MOFs promotes Ov stabilization. Ovs can be effectively preserved by the coating of a thin NiFe‐MOFs layer, leading to a photoanode of enhanced photocurrent and stability.
A core–shell Ov‐BiVO4@NiFe‐MOFs photoanode was constructed via a coordination‐assisted self‐assembly method. A NiFe‐MOFs thin layer acts as protective layer and cocatalyst to shift active sites from oxygen vacancies to NiFe‐MOFs, leading to improved stability and activity for OER. This molecular‐based approach tailors the coordination and electronic structure of active sites and provides mechanistic insights for rational design of photocatalysts.
The inducible expression of the mitochondrial translocator protein 18 kDa (TSPO) by activated microglia is a prominent, regular feature of acute and chronic-progressive brain pathology. This ...expression is also the rationale for the continual development of new TSPO binding molecules for the diagnosis of "neuroinflammation" by molecular imaging. However, there is in the normal brain an ill-defined, low-level constitutive expression of TSPO. Taking advantage of healthy TSPO knockout mouse brain tissue to validate TSPO antibody specificity, this study uses immunohistochemistry to determine the regional distribution and cellular sources of TSPO in the normal mouse brain. Fluorescence microscopy revealed punctate TSPO immunostaining in vascular endothelial cells throughout the brain. In the olfactory nerve layers and glomeruli of the olfactory bulb, choroid plexus and ependymal layers, we confirm constitutive TSPO expression levels similar to peripheral organs, while some low TSPO expression is present in regions of known neurogenesis, as well as cerebellar Purkinje cells. The distributed-sparse expression of TSPO in endothelial mitochondria throughout the normal brain can be expected to give rise to a low baseline signal in TSPO molecular imaging studies. Finally, our study emphasises the need for valid and methodologically robust verification of the selectivity of TSPO ligands through the use of TSPO knockout tissues.
Due to the presence of core effects of high‐entropy materials, it is believed that the impact of carbon vacancy in high‐entropy carbides may differ from that of transition metal monocarbides. In this ...work, nonstoichiometric high‐entropy carbides (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C1−x (HEC1−x) with variable carbon vacancy concentration were fabricated by spark plasma sintering using powder mixtures of high‐entropy carbide and metallic powders. Compared with the corresponding monocarbides, the decline rates of lattice constant and elastic modulus were obviously slower as carbon vacancy concentration increased, indicating a more rigid crystalline lattice in the high‐entropy carbide. The valence electron number for HEC1−x ceramics with the highest hardness is 7.6, which is inconsistent with the theoretically predicted value of 8.4 for the traditional transition metal carbides. When the carbon vacancy concentration in HEC1−x ceramics is above 20%, the promoting effect of carbon vacancy on grain growth will outweigh the inhibiting effect of sluggish diffusion on grain growth, causing grains to grow quickly.
Person re-identification is a crucial task of identifying pedestrians of interest across multiple surveillance camera views. For person re-identification, a pedestrian is usually represented with ...features extracted from a rectangular image region that inevitably contains the scene background, which incurs ambiguity to distinguish different pedestrians and degrades the accuracy. Thus, we propose an end-to-end foreground-aware network to discriminate against the foreground from the background by learning a soft mask for person re-identification. In our method, in addition to the pedestrian ID as supervision for the foreground, we introduce the camera ID of each pedestrian image for background modeling. The foreground branch and the background branch are optimized collaboratively. By presenting a target attention loss, the pedestrian features extracted from the foreground branch become more insensitive to backgrounds, which greatly reduces the negative impact of changing backgrounds on pedestrian matching across different camera views. Notably, in contrast to existing methods, our approach does not require an additional dataset to train a human landmark detector or a segmentation model for locating the background regions. The experimental results conducted on three challenging datasets, i.e. , Market-1501, DukeMTMC-reID, and MSMT17, demonstrate the effectiveness of our approach.
Although tumor mutation burden (TMB) has been well known to predict the response to immune checkpoint inhibitors (ICI), lack of randomized clinical trial data has restricted its clinical application. ...This study aimed to explore the significance and feasibility of biomarker combination based on TMB and copy-number alteration (CNA) for the prognosis of each tumor and prediction for ICI therapy in metastatic pan-cancer milieu.
Non-ICI-treated MSK pan-cancer cohort was used for prognosis analysis. Three independent immunotherapy cohorts, including non-small cell lung cancer (
= 240), skin cutaneous melanoma (
= 174), and mixed cancer (Dana-Farber,
= 98) patients from previous studies, were analyzed for efficacy of ICI therapy.
TMB and CNA showed optimized combination for the prognosis of most metastatic cancer types, and patients with TMB
CNA
showed better survival. In the predictive analysis, both TMB and CNA were independent predictive factors for ICI therapy. Remarkably, when TMB and CNA were jointly analyzed, those with TMB
CNA
showed favorable responses to ICI therapy. Meanwhile, TMB
CNA
as a new biomarker showed better prediction for ICI efficacy compared with either TMB-high or CNA-low alone. Furthermore, analysis of the non-ICI-treated MSK pan-cancer cohort supported that the joint stratification of TMB and CNA can be used to categorize tumors into distinct sensitivity to ICI therapy across pan-tumors.
The combination of TMB and CNA can jointly stratify multiple metastatic tumors into groups with different prognosis and heterogeneous clinical responses to ICI treatment. Patients with TMB
CNA
cancer can be an optimal subgroup for ICI therapy.
The definition of hypervirulent Klebsiella pneumoniae (hvKp), traditionally regarded as hypermucoviscosity, is controversial. However, data based on both phenotype (hypermucoviscous) and genetic ...(aerobactin) criteria are limited.
A retrospective study was conducted in 175 geriatric patients between January 2008 and January 2014. The clinical and molecular data, including antimicrobial susceptibility testing, extended-spectrum-β-lactamase (ESBL) production, virulence gene, and multilocus sequence typing of the hvKp-group (hypermucoviscosity and aerobactin positive) were compared with those of classic K. pneumoniae (cKp) isolates.
Of 175 Kp isolates, 45.7% were hvKp. In pathogenicity, K1, K2, magA, rmpA, and rmpA2 genes were strongly associated with hvKp (P < 0.01). In the hvKp group, invasive infections (P < 0.000), liver abscess (P = 0.008), abdominal infection (P = 0.002) and septic shock (P = 0.035) are significantly higher than cKp group. Patients with better nutritional status were frequently infected with hvKp. However, host inflammatory reaction is most severe in hvKp group. Patients with diabetes (odds ratio OR = 2.548) and digestive diseases (OR = 2.196) are more likely to be infected with hvKp. Importantly, the detection of hvKp isolates increased from January 2008 to January 2010, January 2010 to January 2012, and January 2010 to January 2014 (12, 30, and 48 isolates, respectively). Overall, 16.3% of hvKp isolates produced ESBLs and 20.0% were MDR-hvKp. Multivariate analysis implied that infection occurred in the ICU (OR = 5.826) and patients with indwelling stomach tubes (OR = 6.461) are independent risk factors for ESBL-hvKp infection.
HvKp, especially ESBL-hvKp and MDR-hvKp, is emerging in the elderly. It is essential to enhance clinical awareness and management of hvKp infections.
In this paper, we study the outage probability of device-to-device (D2D)-communication-enabled cellular networks from a general threshold-based perspective. Specifically, a mobile user equipment ...(TIE) transmits in D2D mode if the received signal strength (RSS) from the nearest base station (BS) is less than a specified threshold β ≥ 0; otherwise, it connects to the nearest BS and transmits in cellular mode. The RSS-threshold-based setting is general in the sense that by varying β from β = 0 to β = ∞, the network accordingly evolves from a traditional cellular network (including only cellular mode) toward a wireless ad hoc network (including only D2D mode). We provide a unified framework to analyze the downlink outage probability in a multichannel environment with Rayleigh fading, where the spatial distributions of BSs and TIEs are well explicitly accounted for by utilizing stochastic geometry. We derive closed-form expressions for the outage probability of a generic TIE and that in both cellular mode and D2D mode and quantify the performance gains in outage probability that can be obtained by allowing such RSS-thresholdbased D2D communications. We show that increasing the number of channels, although able to support more cellular TIEs, may result in an increase of outage probability in the D2D-enabled cellular network. The corresponding condition and reason are also identified by applying our framework.
To achieve energy neutral wastewater treatment, mainstream anaerobic ammonium oxidation (anammox) has attracted extensive attention in the past decade. However, the relatively high effluent nitrogen ...concentration (>10 mg N L-1) remains a significant barrier hindering its practical implementation. A novel technology integrating the anammox and denitrifying anaerobic methane oxidation (DAMO) reactions in a membrane biofilm reactor (MBfR) was developed in this study to enhance the mainstream anammox process. With the hydraulic retention time (HRT) progressively decreased from 12 to 4 h, the total nitrogen (TN) removal rate increased stepwise from 0.09 to 0.28 kg N m−3 d−1, with an effluent TN concentration below 3.0 mg N L-1 achieved. Mass balance analysis showed that 30–60% of the nitrate produced by the anammox reaction was reduced back to nitrite by DAMO archaea, and the anammox and DAMO bacteria were jointly responsible for nitrite removal with contributions of >90% and <10%, respectively. Additionally, the established MBfR was robust and achieved consistently high effluent quality with >90% TN removal when the influent nitrite to ammonium molar ratio varied in the range of 1.17−1.55. Fluorescence in situ hybridization (FISH) and 16S rRNA gene sequencing indicated that anammox bacteria, DAMO bacteria and DAMO archaea jointly dominated the biofilm, and were likely the key contributors to nitrogen removal. This is the first study that a high nitrogen removal rate (>0.2 kg N m−3 d−1) and satisfactory effluent quality (∼3 mg TN L-1) were achieved simultaneously by integrating anammox and DAMO reactions in mainstream wastewater treatment.
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•A functional biofilm integrating anammox and DAMO organisms was developed in MBfR.•Practically useful rate was obtained for mainstream nitrogen removal.•Effluent TN concentration below 5 mg N L-1 was achieved.
Ultra-high temperature ceramics (UHTCs) are considered as a family of nonmetallic and inorganic materials that have melting point over 3000 °C. Chemically, nearly all UHTCs are borides, carbides, and ...nitrides of early transition metals (e.g., Zr, Hf, Nb, Ta). Within the last two decades, except for the great achievements in the densification, microstructure tailoring, and mechanical property improvements of UHTCs, many methods have been established for the preparation of porous UHTCs, aiming to develop high-temperature resistant, sintering resistant, and lightweight materials that will withstand temperatures as high as 2000 °C for long periods of time. Amongst the synthesis methods for porous UHTCs, sol-gel methods enable the preparation of porous UHTCs with pore sizes from 1 to 500 urn and porosity within the range of 60%-95% at relatively low temperature. In this article, we review the currently available sol-gel methods for the preparation of porous UHTCs. Templating, foaming, and solvent evaporation methods are described and compared in terms of processing-microstructure relations. The properties and high temperature resistance of sol-gel derived porous UHTCs are discussed. Finally, directions to future investigations on the processing and applications of porous UHTCs are proposed.
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