Search

Abstract Background Antimicrobial resistance and bacterial hypermucoviscosity, associated with escalating production of capsules, constitute major challenges for the clinical management of Klebsiella pneumoniae (K. pneumoniae) infections. This study investigates the association and underlying mechanism between ceftazidime-avibactam (CAZ-AVI) resistance and bacterial hypermucoviscosity in Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-Kp). Results The proportion of CAZ-AVI-sensitive clinical isolates exhibiting the hypermucoviscous phenotype was significantly lower than that of the resistant strains (5.6% vs. 46.7%, P

Rock deformation modulus is one of the key parameters for the design and construction of underground rock engineering. Obtaining accurate rock deformation modulus is crucial for a comprehensive analysis of the deformation behavior of the surrounding rock in deep rock engineering. To achieve this goal, the commonly used methods for calculating rock deformation modulus are systematically sorted out and summarized. Furthermore, the rock deformation modulus is inverse-calculated by simulating in-situ tests using the finite element method, and the results are verified and analyzed by comparing them with the in-situ test results. For the actual project of deep shaft, a numerical calculation model is established to conduct an inversion analysis of rock deformation modulus of different lithologies in the deep strata. Additionally, a sensitivity analysis is performed on different strength criteria, Poisson's ratio and rock cohesion on rock deformation modulus. Finally, the numerical simulation inversion results are compared and discussed with the empirical formula calculation results. The results show that the values of rock deformation modulus obtained from numerical inversion using finite element method are in good agreement with those calculated based on the experimental rigid plate load test; While Poisson's ratio does have some influence on rock deformation modulus, the sensitivity of rock deformation modulus to Poisson's ratio is generally low; When the cohesion of the rock mass is small, the choice of strength criterion has a significant influence on the inversion results of deformation modulus, and vice versa; the sensitivity of the rock deformation modulus to the changes of the rock cohesion varies depending on the depth and lithology of the strata; the deformation modulus of the rock mass obtained by numerical inversion has a good correlation with some empirical equations. Therefore, the numerical simulation and empirical formulae are useful during planning, design and development of deep rock projects to perform the inversion calculation of rock deformation modulus, thereby ensuring greater safety and economy.

Abstract Background Nonalcoholic fatty liver disease (NAFLD) is a chronic disease with an increasing incidence, which can further develop into liver fibrosis and hepatocellular carcinoma at the end stage. Alantolactone (Ala), a sesquiterpene lactone isolated from Asteraceae, has shown anti-inflammatory effects in different models. However, the therapeutic effect of Ala on NAFLD is not clear. Methods C57BL/6 mice were fed a high-fat diet (HFD) to induce NAFLD. After 16 weeks, Ala was administered by gavage to observe its effect on NAFLD. RNA sequencing of liver tissues was performed to investigate the mechanism. In vitro, mouse cell line AML-12 was pretreated with Ala to resist palmitic acid (PA)-induced inflammation, oxidative stress and fibrosis. Results Ala significantly inhibited inflammation, fibrosis and oxidative stress in HFD-induced mice, as well as PA-induced AML-12 cells. Mechanistic studies showed that the effect of Ala was related to the induction of Nrf2 and the inhibition of NF-κB. Taken together, these findings suggested that Ala exerted a liver protective effect on NAFLD by blocking inflammation and oxidative stress. Conclusions The study found that Ala exerted a liver protective effect on NAFLD by blocking inflammation and oxidative stress, suggesting that Ala is an effective therapy for NAFLD.

This paper assessed the electromigration behavior of ethanolamine and its efficiency as a corrosion inhibitor of rebar during the realkalization. Cylindrical concrete specimen (diameter 45 mm, height 20 mm) with steel rebar (6 mm in diameter, 35 mm in length) were artificially carbonated and corroded in an accelerated manner with impressed anodic current. The specimens were realkalized in the electrolyte solution containing ethanolamine, while the steel rebars were connected to the cathodic current (200 mA·h, 1 A/m2). After 25 days of monitoring the repair process, experimental data revealed notable changes in electrochemical parameters. The corrosion potential increased from −627 mV to −236 mV, signifying a reduction in corrosion activity. The cathodic exchange current density decreased from 4.9 μA/cm2 to 2.3 μA/cm2, showing a decrease in the corrosion rate. Also, the pH value of the solution dropped to a comparatively lower level, the ethanolamine and potassium ion concentrations decreased from 22 to 30.54 g/L to 3.22 and 10.23 g/L, respectively. Moreover, nitrogen detection on the steel surface and varied levels of ethanolamine concentration at different depths in the concrete were also measured, both indicating a clear migration of inhibitor to the steel surface to form a passive film.

The issue of significant floor heave deformation in gob-side entry retaining has long been a challenging problem in the context of longwall mining. This paper studies the floor heave failure mechanism and control method for gob-side entry retaining with concrete blocks in Guizhou Faer Coal Mine in China. Based on Rankine’s earth pressure theory, the effective shear stress equation for the plastic slip of roadway floor is established. The deformation mechanism of floor heave in a retaining roadway with a block wall is revealed in this study. The new comprehensive control method is proposed, encompassing roof pre-splitting blasting for pressure relief, reinforcing cables for roof control, double directions control bolts for concrete block, and pliability cushion yielding pressure. FLAC3D numerical calculation model is established, which shows that the new method can effectively reduce the average vertical stress peak value of the entity coal floor by 34.6% and significantly reduce the pressure source causing the roadway floor heave. Besides, a multi-parameter real-time online monitoring system for mine pressure was designed, and field tests were carried out. The results show that the maximum value of roadway floor heave under the new method is 163 mm, reduced by 66.9%, and the roadway floor heave is effectively controlled. These research findings offer a fresh perspective and new ideas for controlling floor heave in mining operations.

Abstract Deprived urban areas, commonly referred to as ‘slums,’ are the consequence of unprecedented urbanisation. Previous studies have highlighted the potential of Artificial Intelligence (AI) and Earth Observation (EO) in capturing physical aspects of urban deprivation. However, little research has explored AI’s ability to predict how locals perceive deprivation. This research aims to develop a method to predict citizens’ perception of deprivation using satellite imagery, citizen science, and AI. A deprivation perception score was computed from slum-citizens’ votes. Then, AI was used to model this score, and results indicate that it can effectively predict perception, with deep learning outperforming conventional machine learning. By leveraging AI and EO, policymakers can comprehend the underlying patterns of urban deprivation, enabling targeted interventions based on citizens’ needs. As over a quarter of the global urban population resides in slums, this tool can help prioritise citizens’ requirements, providing evidence for implementing urban upgrading policies aligned with SDG-11.

Abstract Background Severe bacterial infections can trigger acute lung injury (ALI) and acute respiratory distress syndrome, with bacterial pathogen‐associated molecular patterns (PAMPs) exacerbating the inflammatory response, particularly in COVID‐19 patients. Cyclic‐di‐GMP (CDG), one of the PAMPs, is synthesized by various Gram‐positve and Gram‐negative bacteria. Previous studies mainly focused on the inflammatory responses triggered by intracellular bacteria‐released CDG. However, how extracellular CDG, which is released by bacterial autolysis or rupture, activates the inflammatory response remains unclear. Methods The interaction between extracellular CDG and myeloid differentiation protein 2 (MD2) was investigated using in vivo and in vitro models. MD2 blockade was achieved using specific inhibitor and genetic knockout mice. Site‐directed mutagenesis, co‐immunoprecipitation, SPR and Bis‐ANS displacement assays were used to identify the potential binding sites of MD2 on CDG. Results Our data show that extracellular CDG directly interacts with MD2, leading to activation of the TLR4 signalling pathway and lung injury. Specific inhibitors or genetic knockout of MD2 in mice significantly alleviated CDG‐induced lung injury. Moreover, isoleucine residues at positions 80 and 94, along with phenylalanine at position 121, are essential for the binding of MD2 to CDG. Conclusion These results reveal that extracellular CDG induces lung injury through direct interaction with MD2 and activation of the TLR4 signalling pathway, providing valuable insights into bacteria‐induced ALI mechanisms and new therapeutic approaches for the treatment of bacterial co‐infection in COVID‐19 patients.

Single Recovery Roadway (SRR) is a novel retraction technology in the non-pillars mining innovation system. In previous support withdrawing, single recovery roadway was usually replaced by a dual-recovery roadway or cut the coal wall before the support. This study is set against the background of the longwall panel at Duanshi Coal Mine, where a mechanical model based on the stress characteristics of a composite cantilever beam was constructed to analyze the failure of the main roof in a single recovery roadway. Through numerical analysis, the relationship between deformation failure of the recovery roadway and interlayer slippage structures was explored, as well as how mining-induced stress distribution and the evolution of key strata fractures impact the stability of the roadway. The results indicate that after the connection of the longwall panel and the recovery roadway, the overlying composite interlayered rock strata are affected by the interlayer slippage structures, leading to significant asymmetric deformation in the surrounding rocks. Additionally, borehole observation data support the theoretical calculations of the cantilever beam model. These research results enhance the understanding of the interlayer slip instability mechanism and provide important guidance for mine design under similar geological conditions.

Abstract The volume evolution behavior of rock fissures and the characteristics of acoustic emission under cyclic loading are critical for rock stability analysis. To study the volume change behavior of monzogranite fissures and the characteristics of acoustic emission signals under cyclic loading, we selected samples of monzogranite at − 1600 m from a gold mine located in the Jiaodong Peninsula at a depth of − 1600 m and investigated the samples using triaxial cyclic loading—unloading tests and acoustic emission monitoring. As the volume change behavior of the monzogranite fissures and acoustic emission signals were monitored and recorded, the calculated fracture volume strain ratio coefficient and acoustic emission entropy value were proposed to describe the evolution process of fissures inside the rock. The research results showed that the volume strain ratio curve of the rock fractures exhibited a logarithmic variation characteristic during the cyclic loading and unloading, and the fracture volume strain ratio better reflected the relative scale of the internal fracture strain in the rock to the total volume strain. The acoustic emission entropy value reflected the crack evolution behavior during the loading and failure processes, which was a rapid decline in the initial stage of loading and a rapid upward trend in the failure stage. The observed “V”-shaped change in the acoustic emission entropy can be used as an early warning for rock failure. The research results can provide theoretical guidance for rock stability analysis.

Increasing tenure security is essential for promoting safe and inclusive urban development and achieving Sustainable Development Goals. However, assessment of tenure security relies on conventional census and survey statistics, which often fail to capture the dimension of perceived tenure insecurity. This perceived tenure insecurity is crucial as it influences local engagement and the effectiveness of policies. In many regions, particularly in the Global South, these conventional methods lack the necessary data to adequately measure perceived tenure insecurity. This study first used household survey data to derive variations in perceived tenure insecurity and then explored the potential of Very-High Resolution (VHR) satellite imagery and spatial data to assess these variations in urban deprived areas. Focusing on the city of Kigali, Rwanda, the study collected household survey data, which were analysed using Multiple Correspondence Analysis to capture variations of perceived tenure insecurity. In addition, VHR satellite imagery and spatial datasets were analysed to characterize urban deprivation. Finally, a Random Forest regression model was used to assess the relationship between variations of perceived tenure insecurity and the spatial characteristics of urban deprived areas. The findings highlight the potential of geospatial information to estimate variations in perceived tenure insecurity within urban deprived contexts. These insights can inform evidence-based decision-making by municipalities and stakeholders in urban development initiatives.

Operation strategy of the integrated wind-hydrogen system is the key to ameliorate the negative impacts of the fluctuated wind power on the hydrogen production capacity and durability of electrolyzer. However, the desalination system supplying pure water to electrolyzers was neglected previously, with which the practical operation strategy of the hybrid wind-hydrogen-desalination system has yet to be investigated. In this work, we proposed a novel control strategy named step-by-step start for wind-hydrogen-desalination system consisting of wind turbine, proton exchange membrane water electrolyzer (PEMWE), battery and batch reverse osmosis (BRO) desalination system, which can produce hydrogen and fresh water. Real-time wind data from Shenzhen, China were used as input to the integrated system. The results demonstrate the wind-hydrogen-desalination system with the proposed strategy can improve the hydrogen production by 17.55 %, the energy efficiency by 17.68 % in August, and increase hydrogen production by 10.29 %, the energy utilization efficiency by 10.44 % in December compared with traditional strategies. At low wind speeds, the switching times of PEMWE for this strategy is higher than the other strategies, while at high wind speeds, the switching times of PEMWE is significantly decreased. This work provides insights into the practical operation strategy for wind-hydrogen-desalination system depending on the real-time wind speed.

The concentration of antimicrobial agents in environments like water and food has increased rapidly, which led to a rapid increase in antimicrobial resistance levels in the environment. Monitoring of bacterial resistance levels is considered as a necessary means to control the bacterial resistance. Reference standards are critical for antimicrobial susceptibility testing. CLSI M45 A3 standard defines pathogenic microorganisms that cause infections less frequently than those covered by CLSI M02, M07, and M100 as Infrequently Isolated or Fastidious Bacteria and specifies antimicrobial susceptibility testing methods. Our study investigated the epidemiology and antimicrobial susceptibility testing data of Infrequently Isolated or Fastidious Bacteria strains isolated from blood specimens in 70 hospitals in Guangdong Province between 2017 and 2021. We defined testing methods other than those specified in CLSI M45 A3 as “Non-Standardized.” The proportion of standardized antimicrobial susceptibility testing for penicillin increased significantly (Corynebacterium spp. 17.4% vs. 50.0% p

Hypervirulent carbapenem-resistant Acinetobacter baumannii (hv-CRAB) has emerged in bloodstream infections (BSI). Cases of BSI caused by hv-CRAB (hv-CRAB-BSI) had posed a significant threat to hospitalized patients. In this study, 31 CRAB strains isolated from Chinese BSI patients were analyzed, of which 24 were identified as hv-CRAB-BSI and 7 as non-hv-CRAB-BSI, using the Galleria mellonella infection model. Patients with hv-CRAB-BSI had higher rates of septic shock (79.2% vs. 14.3%, p = 0.004) and mortality (66.7% vs. 14.3%, p = 0.028). All strains were resistant to most antibiotics but sensitive to colistin. Hv-CRAB-BSI showed lower resistance to minocycline than non-hv-CRAB-BSI (54.2% vs. 100%, p = 0.03). Whole-genome sequencing revealed that the detection rates of immune modulation genes ptk and epsA in hv-CRAB-BSI were significantly higher than in non-hv-CRAB-BSI (91.7% vs. 28.6%, p = 0.002). Additionally, all ST457 hv-CRAB-BSI lacked abaR, and all ST1486 non-hv-CRAB-BSI lacked adeG. The checkerboard dilution method assessed the efficacies of various antibiotic combinations, revealing that although synergism was rarely observed, the combination of colistin and minocycline showed the best efficacy for treating CRAB-BSI, regardless of whether the infections were hv-CRAB-BSI or non-hv-CRAB-BSI. These findings highlight the importance of analyzing molecular characteristics and exploring effective treatment strategies for hv-CRAB-BSI.

This study introduces a machine learning-based framework for mapping street patterns in urban morphology, offering an objective, scalable approach that transcends traditional methodologies. Focusing on six diverse cities, the research employed supervised machine learning to classify street networks into gridiron, organic, hybrid, and cul-de-sac patterns with the street-based local area (SLA) as the unit of analysis. Utilising quantitative street metrics and GIS, the study analysed the urban form through the random forest method, which reveals the predictive features of urban patterns and enables a deeper understanding of the spatial structures of cities. The findings showed distinctive spatial structures, such as ring formations and urban cores, indicating stages of urban development and socioeconomic narratives. It also showed that the unit of analysis has a major impact on the identification and study of street patterns. Concluding that machine learning is a critical tool in urban morphology, the research suggests that future studies should expand this framework to include more cities and urban elements. This would enhance the predictive modelling of urban growth and inform sustainable, human-centric urban planning. The implications of this study are significant for policymakers and urban planners seeking to harness data-driven insights for the development of cities.

The structural, mechanical, and electronic properties of cubic Cr0.5-xAl0.5TMxN, doped with TM (transition metal) elements (TM = Ti, V, Y, Zr, Hf, and Ta) at low concentrations (x = 0.03 and 0.06), was investigated by first-principles calculations. The results of the structural properties calculations reveal that the addition of Ti, Y, Hf, Zr, and Ta expand the volume, while V has the opposite effect. All doped compounds are thermodynamically stable, and Cr0.5-xAl0.5TMxN with TM = Ti is energetically more favorable than other doped compounds. At the same doping concentration, Cr0.5-xAl0.5VxN possesses the highest stiffness, hardness, and resistance to external forces due to its greatest mechanical properties, and Cr0.5-xAl0.5TaxN possesses the highest elastic anisotropy and the lowest Young’s modulus. Substituting Cr atoms with TM atoms in a stepwise manner results in a decrease in the bulk modulus, shear modulus, Young’s modulus, and theoretical hardness of Cr0.5-xAl0.5TMxN, while increasing its toughness. Based on the calculation results of the total and partial density of states of Cr0.5Al0.5N and Cr0.47Al0.5TM0.03N, all compounds exhibit metallic behavior as indicated by the finite density of states at the Fermi level. The contribution of Ti-3d, V-3d, and Ta-3d orbitals at Fermi level is significantly higher than that of other TM atoms, resulting in a more pronounced metallic character for Cr0.47Al0.5Ti0.03N, Cr0.47Al0.5V0.03N, and Cr0.47Al0.5Ta0.03N.

Deep carbon cycle is crucial for mantle dynamics and maintaining Earth's habitability. Recycled carbonates are a strong oxidant in mantle carbon-iron redox reactions, leading to the formation of highly oxidized mantle domains and deep carbon storage. Here we report high Fe3+/ΣFe values in Cenozoic intraplate basalts from eastern China, which are correlated with geochemical and isotopic compositions that point to a common role of carbonated melt with recycled carbonate signatures. We propose that the source of these highly oxidized basalts has been oxidized by carbonated melts derived from the stagnant subducted slab in the mantle transition zone. Diamonds formed during the carbon-iron redox reaction were separated from the melt due to density differences. This would leave a large amount of carbon (about four times of preindustrial atmospheric carbon budget) stored in the deep mantle and isolated from global carbon cycle. As such, the amounts of subducted slabs stagnated at mantle transition zone can be an important factor regulating the climate. [ABSTRACT FROM AUTHOR]

Developing cost-effective and high-performance electrocatalysts for oxygen reduction reaction (ORR) is critical for clean energy generation. Here, we propose an approach to the synthesis of iron phthalocyanine nanotubes (FePc NTs) as a highly active and selective electrocatalyst for ORR. The performance is significantly superior to FePc in randomly aggregated and molecularly dispersed states, as well as the commercial Pt/C catalyst. When FePc NTs are anchored on graphene, the resulting architecture shifts the ORR potentials above the redox potentials of Fe2+/3+ sites. This does not obey the redox-mediated mechanism operative on conventional FePc with a Fe2+--N moiety serving as the active sites. Pourbaix analysis shows that the redox of Fe2+/3+ sites couples with HO- ions transfer, forming a HO-Fe3+-N moiety serving as the ORR active sites under the turnover condition. The chemisorption of ORR intermediates is appropriately weakened on the HO-Fe3+-N moiety compared to the Fe2+-N state and thus is intrinsically more ORR active. [ABSTRACT FROM AUTHOR]

Abstract The paradigm of lunar crust formation has been widely applied to other terrestrial bodies, but the nature of early crust building on the Moon remains enigmatic. Here we report non-Apollo-like highland clasts from the Chang’e-5 mission and find high-alumina melts enclosed in a noritic anorthosite. Geochemistry and phase equilibria modeling suggest that the melt is compositionally parental to lunar magnesian-suite rocks, and was sourced from a plagioclase-bearing, orthopyroxene-dominated upper mantle ( ~ 4.5 kbar and 1225°C). It was formed as a direct consequence of upper mantle melting at the onset of gravitational instability. We propose a continuous early crust formation on the Moon, started from multiple anorthositic cumulate flotations, to upper mantle melting caused by small-scale, in-situ overturn, and eventually ended up by decompression melting of lower mantle cumulates following large-scale, global overturn.

Abstract The neurotoxic α-synuclein (α-syn) oligomers play an important role in the occurrence and development of Parkinson’s disease (PD), but the factors affecting α-syn generation and neurotoxicity remain unclear. We here first found that thrombomodulin (TM) significantly decreased in the plasma of PD patients and brains of A53T α-syn mice, and the increased TM in primary neurons reduced α-syn generation by inhibiting transcription factor p-c-jun production through Erk1/2 signaling pathway. Moreover, TM decreased α-syn neurotoxicity by reducing the levels of oxidative stress and inhibiting PAR1-p53-Bax signaling pathway. In contrast, TM downregulation increased the expression and neurotoxicity of α-syn in primary neurons. When TM plasmids were specifically delivered to neurons in the brains of A53T α-syn mice by adeno-associated virus (AAV), TM significantly reduced α-syn expression and deposition, and ameliorated the neuronal apoptosis, oxidative stress, gliosis and motor deficits in the mouse models, whereas TM knockdown exacerbated these neuropathology and motor dysfunction. Our present findings demonstrate that TM plays a neuroprotective role in PD pathology and symptoms, and it could be a novel therapeutic target in efforts to combat PD. Schematic representation of signaling pathways of TM involved in the expression and neurotoxicity of α-syn. A TM decreased RAGE, and resulting in the lowered production of p-Erk1/2 and p-c-Jun, and finally reduce α-syn generation. α-syn oligomers which formed from monomers increase the expression of p-p38, p53, C-caspase9, C-caspase3 and Bax, decrease the level of Bcl-2, cause mitochondrial damage and lead to oxidative stress, thus inducing neuronal apoptosis. TM can reduce intracellular oxidative stress and inhibit p53-Bax signaling by activating APC and PAR-1. B The binding of α-syn oligomers to TLR4 may induce the expression of IL-1β, which is subsequently secreted into the extracellular space. This secreted IL-1β then binds to its receptor, prompting p65 to translocate from the cytoplasm into the nucleus. This translocation downregulates the expression of KLF2, ultimately leading to the suppression of TM expression. By Figdraw.