Search

Objective Posterior condylar offset (PCO) and anterior condylar offset (ACO) exert an influence on the sagittal alignment in total knee arthroplasty (TKA). However, there is no common consensus that the variation range of posterior condylar offset (PCO) is associated with patient‐reported outcome measures (PROMs) and the optimum variation range of PCO. This study aims to investigate the correlation between PCO and the PROMs of primary TKA for osteoarthritis (OA) and find out the optimal variation range of the PCO. Methods In this study, we performed a radiographic analysis of 106 patients (112 knees) with primary TKA. Patients were divided into two cohorts (A and B) according to the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC). Correlations between the sagittal parameter and WOMAC were investigated using univariate and multivariate analysis. The receiver operating characteristic (ROC) curve was used to establish the cut‐off value for the optimal variation range. We then further investigated how different variation range affects the WOMAC subscale score and forgotten‐joint‐score‐12 (FJS‐12). Results Univariate analysis revealed a correlation between the variation range of PCO (p

V and Cr bimetals are utilized as interlayers in the vacuum diffusion bonding of TA2 Ti and 20# steel to prevent the formation of Ti–Fe intermetallic compounds and improve the interface compatibility. The microstructure and mechanical properties of the diffusion-bonded joints are investigated using optical microscopy, scanning electron microscopy combined with energy dispersive spectroscopy, transmission electron microscopy, X-ray diffraction, nanoindentation, and tensile testing. The results indicate that the V/Cr bimetallic interlayer effectively inhibits the formation of Ti–Fe intermetallic compounds, with solid solutions without these compounds present at the Ti/V and steel/Cr interfaces. However, a 1–3-μm-thick continuous, hard, brittle vanadium carbide layer with hardness and elastic modulus value of 6.66 GPa and 201.55 GPa is unexpectedly discovered at the interface between V and Cr. The fracture morphology analysis reveals that the continuous carbide layer at the V/Cr interface is the primary cause of joint failure. The tensile strength of the joint remains relatively stable with an increase in the bonding temperature, whereas the elongation gradually decreases. A maximum tensile strength of 252 MPa is achieved with an elongation of 4.3%.

The latest review published in Nature Reviews Drug Discovery by Michael W. Mullowney and co-authors focuses on the use of artificial intelligence techniques, specifically machine learning, in natural product drug discovery. The authors discussed various applications of AI in this field, such as genome and metabolome mining, structural characterization of natural products, and predicting targets and biological activities of these compounds. They also highlighted the challenges associated with creating and managing large datasets for training algorithms, as well as strategies to address these obstacles. Additionally, the authors examine common pitfalls in algorithm training and offer suggestions for avoiding them.

The latest study published in Nature by Andrew R. Burns, Peter J. Roy and co-authors is highlighted in this paper, they investigated a series of novel nematicidal compounds, including Selectivin-A and Selectivin-E, and explored their mechanism of action. Experiments have displayed that the Selectivin compound is inactive to human cells, fish, fungi, insects and even beneficial nematodes. In the exploration of its mechanism of action, it was found that the mechanism of action of Selectivin is different with those of commercial nematocides: Selectivin needs to be activated by biotin produced by nematodes, after that they can be transformed into compounds with high nematicidal activity. This proves that the family of Selectivin compounds has the advantages of high selectivity and environmental friendliness, and their mechanism of action is completely new, proposing a completely new path for the development of new nematicides.

Abstract Selective molecular recognition is an important alternative to the energy-intensive industrial separation process. Porous coordination polymers (PCPs) offer designing platforms for gas separation because they possess precise controllability over structures at the molecular level. However, PCPs-based gas separations are dominantly achieved using strong adsorptive sites for thermodynamic recognition or pore-aperture control for size sieving, which suffer from insufficient selectivity or sluggish kinetics. Developing PCPs that work at high temperatures and feature both high uptake capacity and selectivity is urgently required but remains challenging. Herein, we report diffusion-rate sieving of propylene/propane (C3H6/C3H8) at 300 K by constructing a PCP material whose global and local dynamics cooperatively govern the adsorption process via the mechanisms of the gate opening for C3H6 and the diffusion regulation for C3H8, respectively, yielding substantial differences in both uptake capacity and adsorption kinetics. Dynamic separation of an equimolar C3H6/C3H8 mixture reveals outstanding sieving performance with a C3H6 purity of 99.7% and a separation factor of 318.

Abstract Background Danggui Sini decoction (DSD), a traditional Chinese medicine formula, has the function of nourishing blood, warming meridians, and unblocking collaterals. Our clinical and animal studies had shown that DSD can effectively protect against oxaliplatin (OXA)-induced peripheral neuropathy (OIPN), but the detailed mechanisms remain uncertain. Multiple studies have confirmed that gut microbiota plays a crucial role in the development of OIPN. In this study, the potential mechanism of protective effect of DSD against OIPN by regulating gut microbiota was investigated. Methods The neuroprotective effects of DSD against OIPN were examined on a rat model of OIPN by determining mechanical allodynia, biological features of dorsal root ganglia (DRG) as well as proinflammatory indicators. Gut microbiota dysbiosis was characterized using 16S rDNA gene sequencing and metabolism disorders were evaluated using untargeted and targeted metabolomics. Moreover the gut microbiota mediated mechanisms were validated by antibiotic intervention and fecal microbiota transplantation. Results DSD treatment significantly alleviated OIPN symptoms by relieving mechanical allodynia, preserving DRG integrity and reducing proinflammatory indicators lipopolysaccharide (LPS), IL-6 and TNF-α. Besides, DSD restored OXA induced intestinal barrier disruption, gut microbiota dysbiosis as well as systemic metabolic disorders. Correlation analysis revealed that DSD increased bacterial genera such as Faecalibaculum, Allobaculum, Dubosiella and Rhodospirillales_unclassified were closely associated with neuroinflammation related metabolites, including positively with short-chain fatty acids (SCFAs) and sphingomyelin (d18:1/16:0), and negatively with pi-methylimidazoleacetic acid, l-glutamine and homovanillic acid. Meanwhile, antibiotic intervention apparently relieved OIPN symptoms. Furthermore, fecal microbiota transplantation further confirmed the mediated effects of gut microbiota. Conclusion DSD alleviates OIPN by regulating gut microbiota and potentially relieving neuroinflammation related metabolic disorder.

The proliferation of Internet of Things (IoT) devices has resulted in a massive increase in data generation, necessitating robust solutions for real-time data processing and analysis. The integration of Unmanned Aerial Vehicles (UAVs) with MEC systems presents a promising enhancement, providing dynamic, mobile edge computing capabilities that can adapt to changing conditions and demands. However, efficiently managing the task offloading and trajectory planning of UAVs in such scenarios poses significant challenges, particularly in maximizing coverage while minimizing time and energy consumption. In this context, this paper proposes a novel UAV-based MEC model utilizing the Multi-Agent Deep Deterministic Policy Gradient (MADDPG) reinforcement learning algorithm to optimize task scheduling and UAV trajectory in real-time. Our model enables UAVs to function as mobile edge servers, dynamically processing and routing tasks between terminal devices and edge servers based on real-time device demands. By incorporating a sophisticated reward function that prioritizes the minimization of system costs-including energy, time, and throughput maximization-our approach not only enhances the operational efficiency of UAV-assisted MEC systems but also improves the quality and responsiveness of edge computing services. After training the MADDPG model in the simulated environment, the experiments show that our approach significantly improved the performance of UAV-assisted MEC systems in real-time scenarios, converging after 50 learning episodes and achieving 90% task completion rate.

Abstract Over the long history of evolution, nature has developed a variety of biological systems with switchable recognition functions, such as the ion transmissibility of biological membranes, which can switch their ion selectivities in response to diverse stimuli. However, developing a method in an artificial host-guest system for switchable recognition of specific guests upon the change of external stimuli is a fundamental challenge in chemistry because the order in the host-guest affinity of a given system hardly varies along with environmental conditions. Herein, we report temperature-responsive recognition of two similar gaseous guests, CO2 and C2H2, with selectivities switched by temperature change by a diffusion-regulatory mechanism, which is realized by a dynamic porous crystal featuring ultrasmall pore apertures with flip-flop locally-motive organic moiety. The dynamic local motion regulates the diffusion process of CO2 and C2H2 and amplifies their rate differences, allowing the crystal to selectively adsorb CO2 at low temperatures and C2H2 at high temperatures with separation factors of 498 (CO2/C2H2) and 181 (C2H2/CO2), respectively.

Crops will be harmed by fungi, pests and weeds during their growth. In the past half century, scientists have conducted in-depth research on natural products extracted from microorganisms, plants or animals, and used natural products and their derivatives as the lead for pesticides discovery. Natural product pesticides have the advantages of easy degradation in the environment, selective control and safety to non-target organisms. This review summarizes the studies on natural products pesticides in recent years, including natural products of chemical modification and biosynthesis, mainly fungicides, herbicides, insecticides and acaricides. We classify natural products according to their active fragments, and discuss their effects on the control of agricultural fungi, pests and weeds. Ultimately, we found that lead discovery based on natural products has great advantages in pesticide development.

The incidence of Mycobacterium marinum infection is on the rise; however, the existing drug treatment cycle is lengthy and often requires multi-drug combination. Therefore, there is a need to develop new and effective anti-M. marinum drugs. Cochliomycin A, a 14-membered resorcylic acid lactone with an acetonide group at C-5′ and C-6′, exhibits a wide range of antimicrobial, antimalarial, and antifouling activities. To further explore the effect of this structural change at C-5′ and C-6′ on this compound’s activity, we synthesized a series of compounds with a structure similar to that of cochliomycin A, bearing ketal groups at C-5′ and C-6′. The R/S configuration of the diastereoisomer at C-13′ was further determined through an NOE correlation analysis of CH3 or CH2 at the derivative C-13′ position and the H-5′ and H-6′ by means of a 1D NOE experiment. Further comparative 1H NMR analysis of diastereoisomers showed the difference in the chemical shift (δ) value of the diastereoisomers. The synthetic compounds were screened for their anti-microbial activities in vitro. Compounds 15–24 and 28–35 demonstrated promising activity against M. marinum, with MIC90 values ranging from 70 to 90 μM, closely approaching the MIC90 of isoniazid. The preliminary structure–activity relationships showed that the ketal groups with aromatic rings at C-5′ and C-6′ could enhance the inhibition of M. marinum. Further study demonstrated that compounds 23, 24, 29, and 30 had significant inhibitory effects on M. marinum and addictive effects with isoniazid and rifampicin. Its effective properties make it an important clue for future drug development toward combatting M. marinum resistance.

Abstract Atopic dermatitis (AD) is a common skin disease involving important immune mechanisms. There is an unmet need for a treatment for this condition. Herein, we focused on elucidating the role of Bi2-xMnxO3 nanospheres (BM) in alleviating skin inflammation in AD-like C57BL/6 mice. The BM was fabricated via sacrificial templates and its biosafety was systematically evaluated. The BM was applied topically to skin lesions of AD-like C57BL/6 mice. The phenotypic and histological changes in the skin were examined carefully. The responses of barrier proteins, inflammatory cytokines and cells to BM were evaluated in HaCaT cells and AD mouse models. The data demonstrated that BM treatment alleviated the AD phenotypes and decreased the level of inflammatory factors, while increasing the expression of the barrier proteins filaggrin/involucrin in the skin. BM effectively reduced the expression of phosphorylated STAT6, which in turn reduced the expression of GATA3, and further decreased the differentiation ratio of Th2 cells, thereby reducing the expression of IL-4. In conclusion, topical drug therapy with BM provides a safe and effective treatment modality for AD by reducing IL-4 and increasing barrier proteins. Graphical Abstract

Abstract Developing efficient artificial photocatalysts for the biomimetic photocatalytic production of molecular materials, including medicines and clean energy carriers, remains a fundamentally and technologically essential challenge. Hydrogen peroxide is widely used in chemical synthesis, medical disinfection, and clean energy. However, the current industrial production, predominantly by anthraquinone oxidation, suffers from hefty energy penalties and toxic byproducts. Herein, we report the efficient photocatalytic production of hydrogen peroxide by protonation-induced dispersible porous polymers with good charge-carrier transport properties. Significant photocatalytic hydrogen peroxide generation occurs under ambient conditions at an unprecedented rate of 23.7 mmol g–1 h–1 and an apparent quantum efficiency of 11.3% at 450 nm. Combined simulations and spectroscopies indicate that sub-picosecond ultrafast electron “localization” from both free carriers and exciton states at the catalytic reaction centers underlie the remarkable photocatalytic performance of the dispersible porous polymers.

Benzoxaborole, a five-membered oxaborole ring fused with a phenyl ring, has demonstrated potent pharmacological activity. In order to explore their potential applications in agriculture, five-membered and six-membered benzoxaborole derivatives were synthesized and evaluated for their fungicidal activity against six common plant pathogenic fungi in vitro. The bioassay results showed that most of the target compounds exhibited significant fungicidal activity at concentrations below 50 μg/mL, particularly the highlighted compounds 4b and 4e, which demonstrated impressive fungicidal activity superior to those of the positive controls. Molecular docking was also performed to confirm the practical value of the active compound as a potential inhibitor of Leucyl-tRNA Synthetase (LeuRS). This study indicates that the designed benzoxaborole derivatives could serve as template molecules for the development of novel fungicides.

Abstract Background/aims To investigate the clinical situation, treatment methods, and clinical predictors of surgical intervention in children with magnetic foreign bodies in the digestive tract. Materials and methods From January 2019 to June 2022, we retrospectively analyzed the clinical data of 72 children who ingested magnetic foreign bodies inadvertently in our hospital, including their general information, admissions, clinical manifestations, and treatment methods, as well as pertinent literature and statistical data. Following software processing, univariate and multivariate logistic regression analyses were conducted to determine the independent risk factors of this study. Results In this study, 16 patients (22.2%) were discharged smoothly following conservative treatment and 19 patients (26.4%) were cured by gastroscopy. The remaining 37 patients (51.4%) were underwent surgery, in which 26 cases developed gastrointestinal perforation. There were statistical differences between surgery group and non- surgery group in the days of eating by mistake, clinical manifestations (nausea and vomiting, intermittent abdominal pain, abdominal muscle tension) and movement trajectory by every 24-h radiograph (P

Lead-based reactor is a new type of reactor using liquid lead or lead-bismuth alloy as a coolant. As the core working element of the main pump, the impeller is subjected to a huge load when conveying heavy metal liquids and is highly susceptible to damage. In this study, we used ANSYS and FLUENT software to investigate the stress, deformation, and creep deformation of the nuclear main pump impeller under a liquid lead-bismuth environment by the fluid-solid coupling method. The maximum equivalent force of the impeller was located at the junction of the blade and hub, which was prone to fatigue damage under the action of alternating load. The stress, deformation, and creep characteristics of the impeller blade were observed to generally increase with rotational speed. Particularly, the junction of the blade root and hub exhibited high susceptibility to stress concentration and fatigue damage. At a flow rate of 0.64 m/s and a speed of 690 r/min, the maximum equivalent force was 16.7 MPa, which was lower than the yield strength of 316L stainless steel. Additionally, the maximum deformation was less than 0.63 mm. Over a five-year period, the creep of the impeller ranged from a minimum of 0.228% to a maximum of 0.447%, indicating that the impeller can reliably operate in a liquid lead-bismuth environment for at least five years.

Abstract Here, we report an asymmetric electrochemical organonickel-catalyzed reductive cross-coupling of aryl aziridines with aryl iodides in an undivided cell, affording β-phenethylamines in good to excellent enantioselectivity with broad functional group tolerance. The combination of cyclic voltammetry analysis of the catalyst reduction potential as well as an electrode potential study provides a convenient route for reaction optimization. Overall, the high efficiency of this method is credited to the electroreduction-mediated turnover of the nickel catalyst instead of a metal reductant-mediated turnover. Mechanistic studies suggest a radical pathway is involved in the ring opening of aziridines. The statistical analysis serves to compare the different design requirements for photochemically and electrochemically mediated reactions under this type of mechanistic manifold.

Abstract The stability of surrounding rock with bolt support depends on the stability within the reinforcement range. To understand the reinforcing mechanism of a rectangular roadway bolt fully and accurately, a quantitative method for evaluating the stability of the surrounding rock of a rectangular roadway must be developed. First, a roof beam model of a rectangular tunnel is established according to the deformation law of surrounding rock. Based on the elastic–plastic theory, the deflection calculation formula can be derived, and the ultimate load of the roof beam can be obtained under the plastic state without support. Second, based on the reinforcement effect of bolts, a model of a surrounding rock reinforcement body is established, the physical and mechanical properties of this body are deduced, and a method for evaluating the stability of surrounding rock is derived. Finally, by considering actual engineering cases, the theoretical calculation results of surrounding rock deformation are compared with the numerical simulation and field monitoring results. Moreover, the influence of different parameters of the bolt support on the mechanical characteristics and stability of reinforcement is investigated. The results show that the theoretical calculations approximate the numerical simulation and field monitoring values, thus verifying the rationality of the theory. The physical and mechanical properties and stability of the surrounding rock reinforcement body are considerably affected by changes in bolt length and spacing. The anchor design must apply the following principle: the bolt must either be long and sparsely spaced or short and densely spaced. The theory presented in this paper provides a relatively simple and fast quantitative calculation method for the study of the surrounding rock stability of bolt-supported rectangular roadways.

Abstract Conventional resistive gate driving circuits suffer from significant recovery gate driving losses, especially at MHz ranges. The increasing gate driving losses brought by high switching frequency place a limitation to the high power density converter design. This paper proposes a novel floating resonant gate driver which maintains high efficiency at several megahertz operating frequency. The gate loss reduction is achieved by adopting a resonant process with driving power recycling. Part of the gate driving power can be recycled to a gate driving capacitor in the gate driving loop during charging and discharging. The proposed gate driver merges the merits of fast switching speed and low gate driving losses. A prototype of LLC power converter with the proposed floating resonant gate driver operating at 3.5 MHz is implemented. According to the experimental verification, the proposed gate driver realized a driving loss reduction by 70% and theoretical analysis is in good agreement with experimental results.

With a combined experimental and computational study, Jin et al. demonstrate that hematite nanoparticles can efficiently degrade phthalates under ambient humidity conditions, with a rate strongly dependent on the exposed facet via bidentate coordination involving neighbor Fe atoms, suggesting their possible use for indoor air purification

Abstract Organic light‐emitting transistors (OLETs) have attracted increasing attention because of their potential applications in next‐generation displays and high‐energy operating devices. However, the simultaneous achievement of high luminescent efficiency and carrier mobility in organic semiconductors remains challenging because the localized excitons are advantageous for light emission, whereas the delocalized carriers are beneficial for efficient charge migration. Herein, we report an organic single crystal of a cyano‐substituted styrene derivative with balanced mobility yielding a record‐high external quantum efficiency of 20.5% in OLETs. Temperature‐dependent I–V curves and electronic structure analyses based on first‐principles calculations were performed to disclose the underlying mechanism as a band transport, which provides an efficient way to achieve high quantum efficiency in OLETs.

The effect of different degrees of cold rolling on the short-term oxidation behavior of Fe-18Cr-8Ni stainless steel oxidized at 1000 °C in N2-21 vol%O2 for 3 h was investigated. The results show that cold rolling deformation reduces the grain size and coincident site lattice (CSL) grain boundary fraction of the alloy. When the deformation exceeds 20%, the oxidation mechanism changes from internal to external oxidation. And the critical concentration of Cr and Si required for forming the protective oxide scale decreases. The formation of continuous Cr2O3 and SiO2 layers on the alloy prevents the diffusion of oxygen from the surface to the matrix. The cold-rolling treatments improve the oxidation resistance of the Fe-18Cr-8Ni austenitic stainless steel at 1000 °C.

Benzoazepine is a well-known pharmacophore presented in several marketed drugs. Here, the authors report the isolation and total syntheses of asperazepanones A and B from coral-derived Aspergillus candidus, two novel pyrrolinone-fused benzoazepine alkaloids with potent anti-inflammatory activities.

Abstract The morphology of eutectic silicon in solidification microstructure is critical to the performance of Al-Si-based alloys. Simulating eutectic Si phase formation has been a challenge in ICME (integrated computational materials engineering) based design and manufacturing of solidification products of Al-Si-based alloys. In this study, our previous three-dimensional (3-D) cellular automaton (CA) model for α-Al dendritic growth was extended to include eutectic (α-Al + Si) transformation in multi-dendrite domains, providing a complete solidification simulation of critically important Al-Si based alloys. The quantitative results of the Si phase in the eutectic microstructure were experimentally validated using scanning electron microscopy and deep etching techniques. The simulation results show a good agreement with the experimental observations and calculations by the Scheil model and lever rule. This 3-D CA model is useful for predicting and optimizing the solidification microstructure including eutectic transformation during solidification processing such as casting, potentially welding, and additive manufacturing.

Abstract Background Liver fibrosis is an outcome of restoring process in chronic liver injury. Human amniotic mesenchymal stem cells (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammatory potential which makes them suitable for treating liver fibrosis. This study aimed to explore the effect and mechanism of hAMSCs on liver fibrosis. Methods hAMSCs were transplanted into carbon tetrachloride (CCl4)-induced liver fibrosis mice via tail vein, and the effects of hAMSCs on hepatic fibrosis were assessed. The effects of hAMSCs and hAMSCs conditional medium (CM) on the activation of hepatic stellate cells (HSCs) were investigated in vivo and in vitro. Antibody array assay was used to identify the cytokines secreted by hAMSCs that may inhibit the activation of HSCs. Finally, the underlying mechanisms were explored by assessing IGF-1R/PI3K/AKT and GSK3β/β-catenin signaling pathways in the activated HSCs (LX-2) with hAMSCs and hAMSCs transfected with corresponding siRNAs. Results Our results showed that hAMSCs possessed the characterizations of mesenchymal stem cells. hAMSCs significantly reduced liver fibrosis and improved liver function in mice by inhibiting HSCs activation in vivo. Both hAMSCs and hAMSC-CM remarkably inhibited the collagen deposition and activation of LX-2 cells in vitro. Antibody array assay showed that insulin-like growth factor binding protein-3 (IGFBP-3), Dickkopf-3 (DKK-3), and Dickkopf-1 (DKK-1) were highly expressed in the co-culture group and hAMSC-CM group compared with LX-2 group. Western blot assay demonstrated that IGFBP-3, DKK-3, and DKK-1 derived from hAMSCs inhibit LX-2 cell activation through blocking canonical Wnt signaling pathway. Conclusions Our results demonstrated that IGFBP-3, Dkk3, and DKK-1 secreted by hAMSCs attenuated liver fibrosis in mice through inhibiting HSCs activation via depression of Wnt/β-catenin signaling pathway, suggesting that hAMSCs or hAMSC-CM provides an alternative therapeutic approach for the treatment of liver fibrosis.

Background Primary thyroid lymphoma (PTL) is a rare type of extranodal lymphoma, which is prone to misdiagnosis and missed diagnosis due to atypical clinical and ultrasonic features. Objective To summarize and analyze the features of 2-D ultrasonography and contrast-enhanced ultrasonography in PTL. Methods A retrospective, comparative analysis was conducted on ultrasonographic features of 16 patients with pathologically confirmed PTL (PTL group) and 16 thyroid cancer patients (thyroid cancer group) recruited from Tangshan Gongren Hospital during December 2012 to December 2020. Results Pathological results of PTL group: 10 cases were diffuse large B-cell lymphoma, 4 cases were mucous-associated lymphoid tissue extranodular marginal zone B-cell lymphoma, 1 case was follicular lymphoma, and 1 case was Burkitt lymphoma. Pathological results of thyroid cancer group: 11 cases were papillary carcinoma, 4 cases were follicular carcinoma and 1 case was medullary carcinoma. The rate of thyroid enlargement in PTL group was higher than that in thyroid cancer group (13/16 vs 5/16) (χ2=8.127, P0.05) . PTL and thyroid cancer groups also had no statistically significant difference in the rate of cervical lymph node metastases (8/16 vs 11/16) (χ2=1.166, P>0.05) . Contrast-enhanced ultrasonography showed high enhancement during arterial and venous phases in PTL, and low enhancement at arterial and venous phases in thyroid cancer. Conclusion PTL has specific ultrasonic manifestations. A diagnosis of PTL could be made when a patient manifests as thyroid enlargement, diffuse hypoechoic, non-calcified, regular-shaped lesions with well-defined margins and posterior echo enhancement, and high enhancement at arterial and venous phases.

Quinolones can possess desirable antibacterial, antiviral and anticancer properties, rending them important synthetic targets for drug discovery purposes. Here, the gram-scale total synthesis of antiviral (+)-aniduquinolone A, possessing a 3,4-dioxygenated 5-hydroxy-4-aryl-quinolin-2(1H)-one skeleton, is reported, as well as its acid-catalyzed rearrangement to aflaquinolones A, C, and D.

In order to quantitatively calculate the critical depth and critical load of mines affected by rock burst, and to achieve effective prevention and control of rock burst in coal mines, this paper proposes a mechanical model for predicting the occurrence of rock burst in coal mine roadways based on catastrophe theory. Additionally, a theoretical calculation formula for initiating rock burst is derived. The first step was to establish a mechanical analysis model, which directly correlated with the in-situ stress, physical and mechanical characteristics of the coal-rock mass, and engineering structural parameters. Following this, a mechanical instability criterion was derived for the key load-bearing circle within the surrounding rock of the roadway. In the final step, the critical depth and load for rock burst initiation were verified for 25 distinct coal mines in China that were prone to rock burst hazards. The research results demonstrate that the discrepancy between the theoretically calculated critical depth and the actual measured statistical values was less than 35%. In addition, the difference between the theoretically determined critical depth and the value calculated by Pan Yishan was less than 32%. Notably, the ratio of the theoretically calculated critical load to the uniaxial compressive strength of the coal-rock mass ranged from 0.38 to 1.93. This aligns with empirical data on rock burst occurrences, as set out in the engineering classification standards for rock masses. These research outcomes substantiated the practical utility of the proposed theory, thereby laying a robust theoretical groundwork for the quantitative control of rock burst. [ABSTRACT FROM AUTHOR]

The properties of the magnetic mold in magnetic mold casting directly determine the quality of the final cast parts. In this study, the magnetic mold properties in magnetic mold casting, were studied utilizing a coupled electromagnetic-structural method through numerical simulation. This study investigated key factors including equivalent stress, the distribution of tensile and compressive stresses, and the area ratio of tensile stress. It compared molds made entirely of magnetic materials with those made partially of magnetic materials. Simulation results indicate that as current increases from 4 A to 8 A, both the initial magnetic mold and the material-replaced magnetic mold initially show an increasing trend in equivalent stress, tensile-compressive stress, and the area ratio of tensile stress, peaking at 6 A before declining. After material replacement, the area ratio of tensile stress at 6 A decreases to 19.84%, representing a reduction of 29.72%. Magnetic molds comprising a combination of magnetic and non-magnetic materials exhibit sufficient strength and a reduced area ratio of tensile stress compared to those made entirely from magnetic materials. This study provides valuable insights for optimizing magnetic mold casting processes and offers practical guidance for advancing the application of magnetic molds. [ABSTRACT FROM AUTHOR]

The presence of ghost waves suppresses the low-frequency energy of signal acquired in marine seismic exploration, while deep structures of the earth mainly correspond to the low-frequency signal components, thus, it is of great significance to improve the low-frequency components suppressed by ghost waves for the detection of deep structures. One of the key parameters of ghost wave suppression is the arrival time difference between the ghost wave and the primary reflected wave, and its accuracy directly affects the effect of ghost wave suppression. Due to the influence of factors such as undulating sea surface, rugged seabed, depth change of reflective layer, and distribution of inhomogeneous media, the arrival time difference between the ghost wave and the primary reflected wave can often not be accurately estimated, resulting in the failure to achieve good results in ghost wave suppression. In this paper, based on the characteristics of the deghosting filter, a filter that does not disturb the high frequency and only improves the low frequency is designed to bypass the suppression of the ghost wave and only focus on the energy improvement of the low-frequency signal. The results of model tests show that the waveform processed by the proposed method is morphologically close to the primary reflected waveform without ghost wave interference. Moreover, the lower the dominant frequency of the seismic signal and the smaller the sinking depth of the towing cable, the stronger the energy enhancement effect of this method on the low-frequency signal. A test applied in the deep reflection seismic profile of the South China Sea has also attained good performances. [ABSTRACT FROM AUTHOR]

Municipal wastewater treatment plants (WWTPs) are sinks of per- and polyfluoroalkyl substances (PFASs) generated by human activities and are also sources of PFASs in aquatic environment. This study analyzed distribution, source and ecological risk of 14 PFASs in influent and effluent samples from 148 Chinese municipal WWTPs. Composition and concentrations of PFASs in the influents and effluents had obvious spatial differences. Fluoropolymer processing aids/wrappers and textile treatments/coatings were found to be the dominant sources in WWTP influents, which accounted for 78.34% of all sources. Consumption structure and metal and transportation equipment manufacturing affected the spatial differences of PFASs in WWTPs. Further, mean removal rate of total PFASs in all WWTPs was −5.45%. The conventional treatment processes can not effectively remove PFASs and no significant difference was found among different treatment processes. However, risk quotient values of PFASs in effluents were all below 0.1, indicating low risk or no risk to aquatic organisms. It should be noted that the composition, source and ecological risk of PFASs in east China were different from the other regions, which need more attentions. This study sheds insights into occurrences of PFASs in municipal WWTPs, which should be helpful for their control strategy development.

ObjectiveTo illustrate the knowledge hotspots and cutting-edge research trends of 18F-FDG PET/CT radiomics, the knowledge structure of was systematically explored and the visualization map was analyzed.MethodsStudies related to 18F-FDG PET/CT radiomics from 2013 to 2021 were identified and selected from the Web of Science Core Collection (WoSCC) using retrieval formula based on an interview. Bibliometric methods are mainly performed by CiteSpace 5.8.R3, which we use to build knowledge structures including publications, collaborative and co-cited studies, burst analysis, and so on. The performance and relevance of countries, institutions, authors, and journals were measured by knowledge maps. The research foci were analyzed through research of keywords, as well as literature co-citation analysis. Predicting trends of 18F-FDG PET/CT radiomics in this field utilizes a citation burst detection method.ResultsThrough a systematic literature search, 457 articles, which were mainly published in the United States (120 articles) and China (83 articles), were finally included in this study for analysis. Memorial Sloan-Kettering Cancer Center and Southern Medical University are the most productive institutions, both with a frequency of 17. 18F-FDG PET/CT radiomics–related literature was frequently published with high citation in European Journal of Nuclear Medicine and Molecular Imaging (IF9.236, 2020), Frontiers in Oncology (IF6.244, 2020), and Cancers (IF6.639, 2020). Further cluster profile of keywords and literature revealed that the research hotspots were primarily concentrated in the fields of image, textural feature, and positron emission tomography, and the hot research disease is a malignant tumor. Document co-citation analysis suggested that many scholars have a co-citation relationship in studies related to imaging biomarkers, texture analysis, and immunotherapy simultaneously. Burst detection suggests that adenocarcinoma studies are frontiers in 18F-FDG PET/CT radiomics, and the landmark literature put emphasis on the reproducibility of 18F-FDG PET/CT radiomics features.ConclusionFirst, this bibliometric study provides a new perspective on 18F-FDG PET/CT radiomics research, especially for clinicians and researchers providing scientific quantitative analysis to measure the performance and correlation of countries, institutions, authors, and journals. Above all, there will be a continuing growth in the number of publications and citations in the field of 18F-FDG PET/CT. Second, the international research frontiers lie in applying 18F-FDG PET/CT radiomics to oncology research. Furthermore, new insights for researchers in future studies will be adenocarcinoma-related analyses. Moreover, our findings also offer suggestions for scholars to give attention to maintaining the reproducibility of 18F-FDG PET/CT radiomics features.

The dynamic adaptation of bacteria to environmental changes is achieved through the coordinated expression of many genes, which constitutes a transcriptional regulatory network (TRN). Bradyrhizobium diazoefficiens USDA110 is an important model strain for the study of symbiotic nitrogen fixation (SNF), and its SNF ability largely depends on the TRN. In this study, independent component analysis was applied to 226 high-quality gene expression profiles of B. diazoefficiens USDA110 microarray datasets, from which 64 iModulons were identified. Using these iModulons and their condition-specific activity levels, we (1) provided new insights into the connection between the FixLJ-FixK2-FixK1 regulatory cascade and quorum sensing, (2) discovered the independence of the FixLJ-FixK2-FixK1 and NifA/RpoN regulatory cascades in response to oxygen, (3) identified the FixLJ-FixK2 cascade as a mediator connecting the FixK2-2 iModulon and the Phenylalanine iModulon, (4) described the differential activation of iModulons in B. diazoefficiens USDA110 under different environmental conditions, and (5) proposed a notion of active-TRN based on the changes in iModulon activity to better illustrate the relationship between gene regulation and environmental condition. In sum, this research offered an iModulon-based TRN for B. diazoefficiens USDA110, which formed a foundation for comprehensively understanding the intricate transcriptional regulation during SNF.

A reliable bonding interface between steel and Ti alloy is required for producing a steel/Ti bimetal composite. In this study, molecular dynamic simulations and diffusion welding experiments using the hot isostatic pressing process were conducted to study the atomic diffusion at the Fe-Ti interface. The simulation results indicate that the diffusion layer thickness is thinner in single crystals compared to polycrystals at the same temperature. This difference may be explained by polycrystals having grain boundaries, which increase atomic disorder and facilitate diffusion. The radial distribution function (RDF) curves for Fe-Fe and Ti-Ti exhibit a similar pattern over time, with a main peak indicating the highest atom density within a specific radius range and relatively strong binding between the central atoms and their nearest neighbors. The observed changes in the diffusion coefficient with temperature in the simulations align well with the experimental results. This study enhances the understanding of Fe-Ti interface diffusion mechanism and provides valuable insights for broader applications of steel/Ti bimetal composites.

It is well known that two-dimensional fermionic systems with a nonzero Chern number must break the time-reversal symmetry, manifested by the appearance of chiral edge modes on an open boundary. Such an incompatibility between topology and symmetry can occur more generally. We will refer to this phenomenon as enforced symmetry breaking (ESB) by topological orders. In this work, we systematically study ESB of a finite symmetry group G_{f} by fermionic invertible topological orders. Mathematically, the group G_{f} is a central extension over a bosonic symmetry group G by the fermion parity group Z_{2}^{f}, characterized by a 2-cocycle λ∈H^{2}(G,Z_{2}). For given G and λ, we are able to obtain a series of criteria on the existence or nonexistence of ESB by the corresponding fermionic invertible topological orders. For 2D systems, we define a set of physical quantities to describe symmetry-enriched invertible topological orders and derive obstruction functions using both fermionic and bosonic languages. The study in the bosonic language is performed after gauging the fermion parity, and we find that some obstruction functions are consequences of conditional anomalies of the bosonic symmetry-enriched topological states, with the conditions inherited from the original fermionic system. The obstruction functions are crucial components of the ESB criteria that we derive. With these criteria, we discover many new ESB examples, e.g., we find that the quaternion group Q_{8} is incompatible with two copies of p+ip superconductors. We also obtain explicit results on the ESB phenomena of the continuous group SU_{f}(N) by 2D invertible topological orders through a different argument.

Fifteen new diterpenoids, namely xishaklyanes A-O (1–15), along with three known related ones (16–18), were isolated from the soft coral Klyxum molle collected from Xisha Islands, South China Sea. The stereochemistry of the new compounds was elucidated by a combination of detailed spectroscopic analyses, chemical derivatization, quantum chemical calculations, and comparison with the reported data. The absolute configuration of compound 18 was established by the modified Mosher’s method for the first time. In bioassay, some of these compounds exhibited considerable antibacterial activities on fish pathogenic bacteria, and compound 4 showed the most effective activity with MIC of 0.225 μg/mL against Lactococcus garvieae.

Excessive inflammation causes chronic diseases and tissue damage. Although there has been drug treatment, its side effects are relatively large. Searching for effective anti-inflammatory drugs from natural products has become the focus of attention. First isolated from Trichoderma longibraciatum, trichodimerol is a natural product with TNF inhibition. In this study, lipopolysaccharide (LPS)-induced RAW264.7 macrophages were used as a model to investigate the anti-inflammatory activity of trichodimerol. The results of nitric oxide (NO) detection, enzyme-linked immunosorbent assay (ELISA), and reactive oxygen species (ROS) showed that trichodimerol could reduce the production of NO, ROS, and the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α. Western blotting results showed that trichodimerol could inhibit the production of inflammatory mediators such as cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) and the protein expression of nuclear transcription factor-kappaB (NF-κB), p-IKK, p-IκB, Toll-like receptor 4 (TLR4), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), cysteinyl aspartate specific proteinase (Caspase)-1, and ASC, which indicated that trichodimerol may inhibit inflammation through the NF-κB and NLRP3 pathways. At the same time, molecular docking showed that trichodimerol can directly combine with the TLR4-MD2 complex. Hence, trichodimerol inhibits inflammation by obstructing the interaction between LPS and the TLR4-MD2 heterodimer and suppressing the downstream NF-κB and NLRP3 pathways.

Background: Excessive inflammation results in severe tissue damage as well as serious acute or chronic disorders, and extensive research has focused on finding new anti-inflammatory hit compounds with safety and efficacy profiles from natural products. As promising therapeutic entities for the treatment of inflammation-related diseases, fusaproliferin and its analogs have attracted great interest. However, the underlying anti-inflammatory mechanism is still poorly understood and deserves to be further investigated.Methods: For the estimation of the anti-inflammatory activity of fusaproliferin (1) and its analogs (2-4)in vitro and in vivo, lipopolysaccharide (LPS)-induced RAW264.7 macrophages and zebrafish embryos were employed. Then, transcriptome analysis was applied to guide subsequent western blot analysis of critical proteins in related signaling pathways. Surface plasmon resonance assays (SPR) combined with molecular docking analyses were finally applied to evaluate the affinity interactions between 1-4 and TLR4 and provide a possible interpretation of the downregulation of related signaling pathways.Results: 1-4 significantly attenuated the production of inflammatory messengers, including nitric oxide (NO), reactive oxygen species (ROS), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β), as well as nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in LPS-induced RAW264.7 macrophages. Transcriptome analyses based on RNA-seq indicated the ability of compound 1 to reverse LPS stimulation and the nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPKs) signaling pathways contribute to the anti-inflammatory process. Experimental verification at the protein level revealed that 1 can inhibit the activation of inhibitor of NF-κB kinase (IKK), degradation of inhibitor of NF-κB (IκB), and phosphorylation of NF-κB and reduce nuclear translocation of NF-κB. 1 also decreased the phosphorylation of MAPKs, including p38, extracellular regulated protein kinases (ERK), and c-Jun N-terminal kinase (JNK). SPR assays and molecular docking results indicated that 1-4 exhibited affinity for the TLR4 protein with KD values of 23.5–29.3 μM.Conclusion: Fusaproliferin and its analogs can be hit compounds for the treatment of inflammation-associated diseases.

In the stage of vehicle demonstration and development, equipment finalization test, and equipment service, an important role is played by the mobility prediction and evaluation method of tracked vehicles under complex road conditions, in which vehicle vibration response evaluation is the main content of off-road mobility prediction and evaluation. In this paper, based on the principle of multibody dynamics, a high-speed tracked vehicle action system model was established by using the simulation analysis method. The vibration response of the vehicle on uneven pavement was evaluated from four aspects: driver comfort, driver absorbed power, occupant handling efficiency, and suspension dynamic travel. Simultaneously, the shock vibration peak value was utilized to evaluate the vibration response of the vehicle during obstacle crossing. Three fitting methods, namely polynomial response surface, Kriging method, and radial basis function neural network, were used to establish approximate models between the design variables and the objective function, respectively. The pros and cons of each approximate model were analyzed by comparing the approximate errors between the predicted values of the fitting model and the actual response values of the simulation model. The results of this paper are of reference significance for the prediction and evaluation of the off-road mobility of high-speed tracked vehicles.

Considering the action of high bearing pressures, a mechanical model of a coal wall mining gateway is established based on the elastic theory. The stress-strain distribution of the coal body is also discussed. According to the compression column model, under the action of the peak-bearing pressure, the maximum horizontal tensile strain in the coal wall is located at 0.65 times the height of the roadway. Furthermore, a theoretical formula for the limit equilibrium zone width and the ultimate tensile strain of the coal body was proposed. The results show that the width of the limit equilibrium zone of the coal wall is related to the ultimate tensile strain of the coal body, the maximum bearing pressure, Poisson’s ratio, the elastic modulus, the original rock stress, and the width of the elastic zone. The maximum shearing breakage depth and position of the floor rock under the plastic flow extruded through coal walls are discussed. Finally, taking the 350–450 m section of the transportation lane in the 14501 working face of Bailiang coal mine as an example, the limit equilibrium of the wall width and the floor breakage depth are calculated on the basis of the relevant parameters. Based on the results, bolt support parameters are designed, which enhance the stability of surrounding rock significantly, providing a theoretical reference for the prevention of liquid gateway floor heave.

Based on the structures of natural products streptochlorin and pimprinine derived from marine or soil microorganisms, a series of streptochlorin derivatives containing the nitrile group were designed and synthesized through acylation and oxidative annulation. Evaluation for antifungal activity showed that compound 3a could be regarded as the most promising candidate—it demonstrated over 85% growth inhibition against Botrytis cinerea, Gibberella zeae, and Colletotrichum lagenarium, as well as a broad antifungal spectrum in primary screening at the concentration of 50 μg/mL. The SAR study revealed that non-substituent or alkyl substituent at the 2-position of oxazole ring were favorable for antifungal activity, while aryl and monosubstituted aryl were detrimental to activity. Molecular docking models indicated that 3a formed hydrogen bonds and hydrophobic interactions with Leucyl-tRNA Synthetase, offering a perspective for the possible mechanism of action for antifungal activity of the target compounds.