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We present a detailed review on the mechanistic understanding and catalyst development of CeO2-based CO2 methanation catalysts. Current challenges for deeper investigations and future perspectives are presented as well.

Cellulose, as a component of green plants, becomes attractive for fabricating biocompatible flexible functional devices but plagued by hydrophilic properties which make it easily break down in water by poor mechanical stability. Here we report a class of SiO2-nanoparticle-decorated bacteria-cellulose meta-skin with a superior stability in water, excellent machining property, ultrathin thickness, and bacteria repairing capacity. We further develop the methodology of meta-skin kirigami that can generate intricate patterns of ~10 μm precision. Benefited from the ultrasound insulation of the surface Cassie-Baxter states, we utilize the meta-skin kirigami to design and fabricate ultrathin (~ 20 μm) and super-light (< 20 mg) chip-scale devices, such as nonlocal holographic meta-lens and the 3D imaging meta-lens, realizing complicated acoustic holograms and high-resolution 3D ultrasound imaging in the far field. The cellulose-based meta-skin kirigami opens the way for exploiting flexible and bio-degradable soft metamaterial devices with functionality customization and key applications in advanced biomedical engineering technologies.

Adenosine triphosphate (ATP) acts as a crucial energy currency in vivo, and it is a widely used energy and/or phosphate donor for enzyme-catalyzed reactions in vitro. In this study, we established an in vitro multi-enzyme cascade system for ATP production. Using adenosine and inorganic polyphosphate (polyP) as key substrates, we combined adenosine kinase and two functionally distinct polyphosphate kinases (PPKs) in a one-pot reaction to achieve chain-like ATP regeneration and production. Several sources of PPK were screened and characterized, and two suitable PPKs were selected to achieve high rates of ATP production. Among these, Sulfurovum lithotrophicum PPK (SlPPK) exhibited excellent activity over a wide pH range (pH 4.0–9.0) and synthesized ATP from ADP using short-chain polyP. Furthermore, it had a half-life > 155.6 h at 45 °C. After optimizing the reaction conditions, we finally carried out the coupling-catalyzed reaction with different initial adenosine concentrations of 10, 20, and 30 mM. The highest yields of ATP were 76.0, 70.5, and 61.3%, respectively. Graphical Abstract

The cross-linking degrees of the prepared carbon nitrides can be controlled by the chloridion concentrations. The obtained heptazine-based, partially cross-linked carbon nitride (PC-CN) shows dramatically enhanced photocatalytic activity.

Enhanced light-matter interaction of a local field is of prime importance in optics as it can improve the performance of nanophotonic devices. Such enhancement can be achieved by utilizing the optical bound states in the continuum (BICs). In this study, a dielectric metasurface is proposed that could enhance the light-matter interactions in graphene. A symmetry-protected BIC was observed in such a metasurface, which could transform into a quasi-BIC with a high quality (

Voids between primary support and secondary lining of existing tunnels pose a serious threat to safety and have become a key challenge for tunnel engineering. Due to the poor bonding performance between concrete slurry backfill and lining concrete, the integrity of supporting structures cannot be guaranteed. In recent years, vault grouting with formwork has proved to be effective in solving this problem. However, few studies have focused on the selection of grouting materials and associated grouting process parameters. In this paper, a slight-expanding concrete slurry is selected as the grouting material. The early strength growth trend of the slight-expanding slurry is explored via laboratory tests. The compatibility of the slight-expanding slurry and the lining concrete is analyzed by comparing the slump, expanding diameter, water retention and compressive strength. Bonding-body specimens were fabricated using a mold developed for this work. Furthermore, we compare the compressive strength and failure mode in order to investigate the bonding properties between the sight-expanding slurry and lining concrete at different grouting intervals and pressures. A reasonable set of operational parameters is subsequently proposed. Finally, field tests undertaken in an expressway tunnel in south China are performed in order to determine the impact of grouting with formwork on tunnel lining, while the grouting effect at the vault is evaluated using a ground penetrating radar. The slight-expanding slurry exhibited a high early strength and rapid hardening. Adding slight-expanding slurry to lining concrete at a volume ratio of 1:0.2 increased the slump, diameter and compressive strength by 13.4%, 15.6%, and 25.0%, respectively. When a grouting interval is less than 6 h, the pressure of grouting with formwork should be no less than 0.2 MPa, while for a grouting interval of 8 h, the grouting pressure should be no less than 0.4 MPa. The grouting pressure of 0.4 MPa exerts a limited effect on the existing secondary lining concrete, and the stress increment produced by grouting accounts for 6–17% of the total increment. The results presented can provide a reference for future tunnel construction.

To evaluate the association between dipeptidyl peptidase 4 inhibitor (DPP-4i) and the incidence of neoplasm in patients with type 2 diabetes (T2D).Pubmed, Medline, Embase, the Cochrane Central Register of Controlled Trials andGenerally, DPP-4i was associated with a decreased incidence of overall neoplasm events in patients with T2D when compared with non-DPP-4i agents (OR = 0.91, 95%CI, 0.8 to 0.97). Moreover, the incidence of rectal neoplasm, especially rectal malignant neoplasm, and the incidence of skin neoplasm were significantly decreased in DPP-4i users. The overall neoplasm events were less frequent in DPP-4i users who were elderly, or male, or obese, or Caucasian, or with over 10 years of diabetes, or with follow-up duration over 52 weeks.DPP-4i was associated with decreased risks of overall neoplasm, rectal neoplasm, rectal malignant neoplasm and skin neoplasm in patients with T2D. The overall neoplasm events were less frequent in patient with DPP-4i treatment who were elderly, male, obese, Caucasian, with long diabetes durations and with long follow-up durations. Further investigations are still required.CRD42021273627.

Cutter wear is an important factor affecting the efficiency of tunnel boring machines (TBMs). In this paper, using a case study from the tunnel project of the XEVIII section of the second phase of the northern Xinjiang water supply project, cutter wear under conditions of high-strength (average strength 120 MPa) surrounding rock is studied. The results show that the cumulative wear of the center cutters and the front cutters increases exponentially with an increase of installation radius, and the cumulative wear of the edge cutters is affected by the installation angle, which increases at first and then decreases with an increase of the installation radius. The single cutter wear of the edge cutters is the largest, of the front cutters is the second largest, and of the center cutters is the smallest. With an increase of surrounding rock strength, the wear of the center cutters and front cutters increases exponentially, and the wear of the edge cutters increases based on a quadratic function per meter, while the cumulative wear per meter increases linearly. Volumetric mass loss increases exponentially with the increase of surrounding rock strength and Cerchar abrasion index and decreases logarithmically with the increase of cutter life index. When the surrounding rock strength is constant, when the revolutions per minute, torque, thrust, and penetration per revolution increase, the cutter wear per meter changes following a quadratic function, which first increases and then decreases. With the increase of penetration rate, the cutter wear per meter changes as a quadratic function, first decreasing and then increasing. Cutter wear is most sensitive to cutter head torque and thrust. In order to reduce cutter wear, it is suggested that cutter head torque should be limited to the range 1100–1300 kN m or 2100–2400 kN m, and the thrust should be limited to the range 9500–11,000 kN or 15,500–16,000 kN.

The catalyzed diesel particulate filter (CDPF) is one of the best methods used to control the particulate matter from internal combustion engine. CeO2 is used as the catalyst in the CDPF due to its...

Study Design: Cross-sectional study. Objectives: Our aim was to describe age-dependent changes of lumbar paraspinal muscle endurance and morphology in Chinese healthy population. We also explored the relationship between paraspinals endurance and morphology. Methods: A total of 181 participants from Chinese community population without chronic low back pain were included. The participants were divided into three groups: young (20-39 years old, n = 29), middle (40-59 years old, n = 93), and elderly (≥ 60 years old, n = 59). The Ito test was performed to evaluate the isometric endurance of paraspinal muscles. The total cross-sectional area (TCSA) and fat infiltration (FI) of multifidus (MF) and erector spinae (ES) were measured at L1-L5 levels on magnetic resonance imaging. Physical activity level was evaluated using the physical activity index and comorbidities were assessed by the modified 5-item frailty index. Results: The elderly group had a shorter performance time of endurance test than the young group and middle-aged group. Correlation analysis showed that age had a significant correlation with endurance test, the average MF TCSA, MF FI, ES TCSA and ES FI of L1-5. In addition, PAI had a significant correlation with endurance test and MF FI. In multiple linear regression analysis, paraspinals endurance was associated with MF FI, ES FI, physical activity level and comorbidities. Conclusion: Age-related decreases in paraspinals endurance and TCSA, and an increase in FI were revealed. Besides, paraspinal muscles FI, but not TCSA, was negatively associated with the endurance of paraspinals.

With the rapid increase in waste activated sludge (WAS), it is urgent to develop appropriate dewatering processes to diminish sludge volume and improve disposal efficiency. In this study, an advanced oxidation process using electrolysis coupled with peroxymonosulfate (E/PMS) was applied to improve the dewaterability of WAS. The results indicated that the sludge water content (WC) and capillary suction time (CST) dropped from 98.4 ± 0.2% and 220.1 ± 2.3 s to 70.7 ± 0.8% and 63.0 ± 1.2 s, respectively, under the following conditions: an electrolysis voltage of 20 V, an electrolysis time of 20 min, and 200 mg/g TS PMS. The increase in sludge zeta potential, surface hydrophobicity, and flowability indicated a significant improvement in sludge dewaterability. SO

In the enzymatic cascade catalysis, it is a big challenge to construct a stable and reusable catalyst with targeted enzymes. The artificial multienzyme reactor has attracted great attention due to its potential for facilitating the performance of enzyme catalysis. In this study, we set up a reliable system that could assemble polyphosphate kinase (PPK) with bifunctional glutathione synthetase (GshF) via SpyCatcher/SpyTag to form multienzyme systems (MESs). Furthermore, MESs could assemble into nanoaggregates by altering the ionic strength, and the larger nanoaggregates could be applied in robust and reusable synthesis of glutathione (GSH). To enhance MES levels in vivo, gene duplication and different coexpression modes were performed. Finally, the optimized production of GSH and oxidized glutathione (GSSG) reached 102.6 and 6.7 mM within 2 h. Compared with the first round, the total yield only decreased by 9.4% after five continuous rounds of biocatalysis.

In the research of multi-sound source localization, the geometric rules for the spatial arrangement of microphone arrays play a decisive role. When faced with multiple sound sources with close positions, traditional typical arrays are difficult to accurately locate the desired signals. Therefore, this paper proposes a leaf-shaped microphone array based on the theory of bionic sunflower spiral arrangement. When the incident signals are multiple sound sources with close positions, combined with the delay-sum beamforming algorithm, the performance of the leaf-shaped array is analyzed from the perspective of positioning accuracy and resolution. Compared with the uniform circular array and Arcondoulis spiral array, the results show that the leaf-shaped array has better resolution and anti-interference ability in the case of multiple sound sources with close positions.

Hepatitis B e antigen (HBeAg) is a widely used marker both for chronic hepatitis B (CHB) clinical management and HBV-related basic research. However, due to its high amino acid sequence homology to hepatitis B core antigen (HBcAg), most of available anti-HBe antibodies are cross-reactive with HBcAg resulting in high interference against accurate measurement of the status and level of HBeAg. In the study, we generated several monoclonal antibodies (mAbs) targeting various epitopes on HBeAg and HBcAg. Among these mAbs, a novel mAb 16D9, which recognizes the SKLCLG (aa −10 to −5) motif on the N-terminal residues of HBeAg that is absent on HBcAg, exhibited excellent detection sensitivity and specificity in pairing with another 14A7 mAb targeting the HBeAg C-terminus (STLPETTVVRRRGR, aa141 to 154). Based on these two mAbs, we developed a novel chemiluminescent HBeAg immunoassay (NTR-HBeAg) which could detect HBeAg derived from various HBV genotypes. In contrast to widely used commercial assays, the NTR-HBeAg completely eliminated the cross-reactivity with secreted HBcAg from precore mutant (G1896A) virus in either cell culture or patient sera. The improved specificity of the NTR-HBeAg assay enables its applicability in cccDNA-targeting drug screening in cell culture systems and also provides an accurate tool for clinical HBeAg detection.

The pyrimidine metabolic pathway is tightly regulated in microorganisms, allowing limited success in metabolic engineering for the production of pathway-related substances. Here, we constructed a four-enzyme coupled system for the in vitro production of uridine triphosphate (UTP). The enzymes used include nucleoside kinase, uridylate kinase, nucleoside diphosphate kinase, and polyphosphate kinase for energy regeneration. All these enzymes are derived from extremophiles. To increase the total and unit time yield of the product, three enzymes other than polyphosphate kinase were modified separately by multiple protein engineering strategies. A nucleoside kinase variant with increased specific activity from 2.7 to 36.5 U/mg, a uridylate kinase variant (specific activity of 37.1 U/mg) with a 5.2-fold increase in thermostability, and a nucleoside diphosphate kinase variant with a 2-fold increase in a specific activity to over 900 U/mg were obtained, respectively. The reaction conditions of the coupled system were further optimized, and a two-stage method was taken to avoid the problem of enzymatic pH adaptation mismatch. Under optimal conditions, this system can produce more than 65 mM UTP (31.5 g/L) in 3.0 h. The substrate conversion rate exceeded 98% and the maximum UTP productivity reached 40 mM/h.

Catalyzed diesel particulate filter (CDPF) combines the functions of the oxidization catalyst and the diesel particulate filter. Due to good redox capacity and oxygen storage capacity, CeO2 is used as the catalyst of CDPF. Since the effects of key factors on the performance of CeO2-based CDPF were rarely reported, it was performed in this study based on a zero-dimensional numerical model using plug flow reactor in which a reaction mechanism was established and validated by the experiment of the thermal gravimetric analyzer. The effects of exhaust gas temperature and three defined parameters including the ratios of NO2 in NOx (α), NOx to soot (β), and catalyst coated amount to carbon loading amount (γ) on catalyst poisoning temperature, N2O concentration, NOx reduction rate and soot regeneration rate were investigated. The results show that the rising exhaust gas temperature causes the reduction of NOx concentration, and the NOx reduction rate comes to 66% when the catalyst poisoning temperature is reached. The soot regeneration rate and the N2O concentration first increase and then decrease as the exhaust gas temperature increases. Meanwhile, the higher exhaust gas temperature suppresses the production of N2O, but raises the possibility of catalyst poisoning. The increasing α and β result in the increase of soot regeneration rate and the decrease of NOx reduction rate. The catalyst poisoning temperature is improved at higher α and lower β. The soot regeneration rate has a fast increase with γ at first and then stabilizes rapidly. The results of this study are valuable to optimize the operation of CDPF.

A rapid in vitro enzymatic biosynthesis system has been developed as a biological manufacturing platform with potential industrial uses. Cytidine 5′-monophosphate (5′-CMP) is a key intermediate in ...

A novel in vitro multi-enzymatic system was constructed for the conversion of CO2 into optically pure N-carbamoyl-L-aspartate and orotate. Four cascade enzymes, carbamoyl phosphate synthase (CPS), aspartate carbamoyl-transferase (ATCase), dihydroorotase (DHOase), and dihydroorotate dehydrogenase (DHOD), were used for the biotransformation of feedstocks into products in one pot while polyphosphate kinase (PPK) was coupled for ATP regeneration. Under the optimal reaction conditions and substrate concentrations, 19.2 mM N-carbamoyl-L-aspartate was produced within 3.0 h, which enabled the synthesis of 15.5 mM orotate. The yields of N-carbamoyl-L-aspartate and orotate based on the added L-aspartic acid reached 96.0% and 93.3%, respectively. This work highlights the ease of producing optically pure N-carbamoyl-L-aspartate and orotate via an in vitro biomanufacturing platform and provides a novel pathway for the utilization of renewable feedstock for the synthesis of value-added commodity chemicals.