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In response to the problems of low strength and high permeability of coal materials in the current physical simulation test of coal mine gas dynamics, a set of experimental research methods for optimizing the molding conditions of hot-pressed briquette. Firstly, a hot-pressed briquette test system was independently established and the advantages and future improvement directions of the test system were summarized. At the same time, based on the Horsfield dense stacking theory, the optimal preparation plan for coal briquette materials was formulated. Finally, a molding condition optimization method was developed that combines the Markov distance measurement method and the golden section method. To verify the effectiveness of the experimental method, the secondary carbonization experiments of briquette were conducted under different molding pressure conditions by controlling the molding temperature to 311.8 ℃, heating rate to 5 ℃/min, and holding time to 5.3 h. The response characteristics of the microstructure, physical and mechanical properties, and permeability characteristics of the hot-pressed briquette under different molding pressure conditions were studied. The results show that with the increase of molding pressure, the total porosity gradually decreases, and the uniaxial compressive strength shows a trend of first increasing and then decreasing. The main forms of failure are block spalling and longitudinal fracture. The initial permeability shows a trend of first decreasing and then increasing, while the minimum permeability shows a trend of first decreasing, then increasing and then decreasing. Using the specific values of each molding condition as the test points, and the key parameters of hot-pressed coal and raw coal as the evaluation parameters, a sample matrix was constructed to calculate the Mahalanobis distance between hot-pressed briquette and raw coal under each molding condition, and then optimize the experimental interval using the golden section method. The optimized final molding pressure is 80 MPa. Under these molding conditions, the density, uniaxial compressive strength, and initial permeability of the hot-pressed briquette produced are 1.137 g/cm3, 12.21 MPa, and 1.32 × 10−15 m2, respectively. They are highly similar to the 1.132 g/cm3, 12.83 MPa, and 1.08 × 10−15 m2 of the raw coal, achieving the goal of improving the strength of the briquette and reducing the permeability of the briquette.

IntroductionFusarium oxysporum is a significant soil-borne fungal pathogen that affects over 100 plant species, including crucial crops like tomatoes, bananas, cotton, cucumbers, and watermelons, leading to wilting, yellowing, growth inhibition, and ultimately plant death. The root rot disease of A. macrocephala, caused by F. oxysporum, is one of the most serious diseases in continuous cropping, which seriously affects its sustainable development.MethodsIn this study, we explored the interaction between A. macrocephala and F. oxysporum through integrated small RNA (sRNA) and degradome sequencing to uncover the microRNA (miRNA)–mediated defense mechanisms.ResultsWe identified colonization of F. oxysporum in A. macrocephala roots on day 6. Nine sRNA samples were sequenced to examine the dynamic changes in miRNA expression in A. macrocephala infected by F. oxysporum at 0, 6, and 12 days after inoculation. Furthermore, we using degradome sequencing and quantitative real-time PCR (qRT-PCR), validated four miRNA/target regulatory units involved in A. macrocephala–F. oxysporum interactions.DiscussionThis study provides new insights into the molecular mechanisms underlying A. macrocephala's early defense against F. oxysporum infection, suggesting directions for enhancing resistance against this pathogen.

RNA interference (RNAi) shows great potential in plant defense against pathogens through RNA-mediated sequence-specific gene silencing. Among RNAi-based plant protection strategies, spray-induced gene silencing (SIGS) is considered a more promising approach because it utilizes the transfer of exogenous RNA between plants and microbes to silence target pathogen genes. The application of nanovesicles significantly enhances RNA stability and delivery efficiency, thereby improving the effectiveness of SIGS and further enhancing plant resistance to diseases and pathogens. This review explores the role of RNAi in plant protection, focusing on the cross-kingdom transport of small RNAs (sRNAs) via extracellular vesicles. It also explores the potential of nanotechnology to further optimize RNA-based plant protection, offering innovative tools and methods in modern plant biotechnology.

Extracellular vesicles (EVs) are vesicle-like structures composed of lipid bilayers, which can be divided into apoptotic bodies, microbubbles and exosomes. They are nanoparticles used for the exchange of information between cells. EVs contains many substances, including protein. With the development of proteomics, we know more about the types and functions of protein in vesicles. The potential functions of proteins in the envelope are mainly discussed, including cell wall construction, fungal virulence transmission, signal transmission and redox reactions, which provides a new perspective for studying the interaction mechanism between fungi and other organisms. The fungal protein markers of EVs are also summarized, which provided an exploration tool for studying the mechanism of vesicles. In addition, the possible role of immune protein in the EVs in the treatment of human diseases is also discussed, which provides new ideas for vaccine development.

Abstract To enrich material types applied to additive manufacturing and enlarge application scope of additive manufacturing in conformal cooling tools, M2 high-speed steel specimens were fabricated by selective laser melting (SLM). Effects of SLM parameters on the microstructure and mechanical properties of M2 high-speed steel were investigated. The results showed that substrate temperature and energy density had significant influence on the densification process of materials and defects control. Models to evaluate the effect of substrate temperature and energy density on hardness were studied. The optimized process parameters, laser power, scan speed, scan distance, and substrate temperature, for fabricated M2 are 220 W, 960 mm/s, 0.06 mm, and 200 ℃, respectively. Based on this, the hardness and tensile strength reached 60 HRC and 1000 MPa, respectively. Interlaminar crack formation and suppression mechanism and the relationship between temperature gradient and thermal stress were illustrated. The inhibition effect of substrate temperature on the cracks generated by residual stresses was also explained. AM showed great application potential in the field of special conformal cooling cutting tool preparation.

Abstract Background Osteoporotic fracture (OPF) is one of the most common skeletal diseases in an aging society. The Chinese medicine formula Buzhong Yiqi Decoction (BZYQD) is commonly used for treating OPF. However, the essential bioactive compounds and the underlying molecular mechanisms that promote fracture repair remain unclear. Methods We used network pharmacology and experimental animal validation to address this issue. First, 147 bioactive BZYQD compounds and 32 target genes for treating OPF were screened and assessed. A BZYQD-bioactive compound-target gene-disease network was constructed using the Cytoscape software. Functional enrichment showed that the candidate target genes were enriched in oxidative stress- and inflammation-related biological processes and multiple pathways, including nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways. Furthermore, an OPF rat model was established and treated with BZYQD. Results The results revealed that BZYQD ameliorated OPF characteristics, including femoral microarchitecture, biomechanical properties, and histopathological changes, in a dose-dependent manner. Results of enzyme-linked immunosorbent assay showed that BZYQD reduced the serum’s pro-inflammatory cytokines [Tumor necrosis factor-alpha (TNF-α), Interleukin (IL)-1β, and IL-6] and improved oxidative stress-related factors [glutathione (GSH) and superoxide dismutase (SOD)]. BZYQD significantly decreased the protein expression of NF-κB in OPF rat femurs, suppressed NF-κB activation, and activated the nuclear factor-erythroid factor 2-related factor (Nrf2)/heme oxygenase 1 (HO-1) and p38 MAPK as well ERK pathways. Conclusions Our results suggest that BZYQD could improve inflammation and oxidative stress during fracture repair by suppressing NF-κB and activating Nrf2/MAPK signaling pathways.

Currently, how to release the heat accumulated in the molten pool rapidly is the key factor in blade repair. We analyzed the problem of the current cooling method in blade additive manufacturing repair. Based on cooling effect, we proposed an advanced flexible multiflow path fixture cooling method for blade additive manufacturing repair. We created a coupled heat transfer model and deduced the heat transfer law for multiflow path conjugate flexible clamping. We obtained the optimal cooling scheme for flexible multiflow paths through numerical analysis. We built an experimental platform and tested the cooling effect of the fixture prototype by experiment. The results show that compared with the current cooling method, the new cooling method not only can lower the initial temperature of the fixture rapidly and realize the steady-state heat transfer between the fixture and the flow path quickly but can also significantly enhance the ability of fluid to participate in heat transfer in new flow paths, which significantly improves the cooling effect. The research results are of great significance for the improvement of aero blade additive manufacturing repair.

NoSQL database can provide massive, high concurrency, and scalable services for storing different types of data. HBase, a type of NoSQL database, in which columns are grouped into column families, is very suitable for storing semi-structured or unstructured spatial vector data. However, since there are few rules and constraints to be followed for the NoSQL database, the design of storage schema for spatial data based on NoSQL is difficult. In this paper, based on our early work, an improved Z-curve storage schema is proposed for spatial vector data. According to our new schema, row key of a geometric object is the Z-curve code of the spatial grids intersected with the geometric object. Moreover, geometric objects with the same row key are stored in a column family. Our proposed method has two features. First, geometric objects adjacent in the location are adjacent in physical storage. Second, redundant exists in storage for improving query accuracy. In our experiments, we compare the improved Z-curve storage schema with a Quadtree storage schema, an R-tree storage schema, and the previous Z-curve storage schema. Query response time, memory usage, and the query accuracy of spatial query on point and range are used to verify the validity of our proposed method. The experimental results show that the two storage schemas based on Z-curve achieve higher query efficiency than the two storage schemas based on tree-the Quadtree storage schema and the R-tree storage schema. More importantly, the query results of the improved Z-curve schema are completely correct, while the query results of the previous Z-curve schema are not.

Nucleic acid detection is widely used in disease diagnosis, food safety, environmental monitoring and many other research fields. The continuous development of rapid and sensitive new methods to detective nucleic acid is very important for practical application. In this study, we developed a rapid nucleic-acid detection method using polymerase chain reaction (PCR) combined with electrokinetic preconcentration based on ion concentration polarization (ICP). Using a Nafion film, the proposed ICP microfluidic chip is utilized to enrich the nucleic acid molecules amplified by PCR thermal cycles. To demonstrate the capability of the microfluidic device and the hybrid nucleic-acid detection method, we present an animal-derived component detection experiment for meat product identification applications. With the reduced cycle numbers of 24 cycles, the detection can be completed in about 35 min. The experimental results show that this work can provide a microfluidic device and straightforward method for rapid detection of nucleic acids with reduced cycle numbers.

Microfluidic devices offer excellent heat transfer, enabling the biochemical reactions to be more efficient. However, the precision of temperature sensing and control of microfluids is limited by the size effect. Here in this work, the relationship between the microfluids and the glass substrate of a typical microfluidic device is investigated. With an intelligent structure design and liquid metal, we demonstrated that a millimeter-scale industrial temperature sensor could be utilized for temperature sensing of micro-scale fluids. We proposed a heat transfer model based on this design, where the local correlations between the macro-scale temperature sensor and the micro-scale fluids were investigated. As a demonstration, a set of temperature-sensitive nucleic acid amplification tests were taken to show the precision of temperature control for micro-scale reagents. Comparations of theoretical and experimental data further verify the effectiveness of our heat transfer model. With the presented compensation approach, the slight fluorescent intensity changes caused by isothermal amplification polymerase chain reaction (PCR) temperature could be distinguished. For instance, the probability distribution plots of fluorescent intensity are significant from each other, even if the amplification temperature has a difference of 1 °C. Thus, this method may serve as a universal approach for micro–macro interface sensing and is helpful beyond microfluidic applications.

A fluorescence microscope is one of the most important tools for biomedical research and laboratory diagnosis. However, its high cost and bulky size hinder the application of laboratory microscopes in space-limited and low-resource applications. Here, in this work, we proposed a portable and cost-effective fluorescence microscope. Assembled from a set of 3D print components and a webcam, it consists of a three-degree-of-freedom sliding platform and a microscopic imaging system. The microscope is capable of bright-field and fluorescence imaging with micron-level resolution. The resolution and field of view of the microscope were evaluated. Compared with a laboratory-grade inverted fluorescence microscope, the portable microscope shows satisfactory performance, both in the bright-field and fluorescence mode. From the configurations of local resources, the microscope costs around USD 100 to assemble. To demonstrate the capability of the portable fluorescence microscope, we proposed a quantitative polymerase chain reaction experiment for meat product authenticating applications. The portable and low-cost microscope platform demonstrates the benefits in space-constrained environments and shows high potential in telemedicine, point-of-care testing, and more.

During the contact between the detumbling end-effector and large non-cooperative target, the recognition of impact pressure distribution is important for estimating the success rate of detumbling mission. To figure out the pressure trends, the ground experiments before the real space mission are necessary. However, due to the drawbacks of the pressure array-like sensor, dynamic characteristics of impact, and unavoidable noise, the accurate dynamic pressure distribution is hard to obtain. In this letter, we propose a recognition method, Impact Pressure Distribution Recognition. The proposed method can quickly generate dynamic impact pressure distribution without limitation on sensor accuracy through pressure data supplement and area correction based on contact model. The analysis results show that our method can efficiently recognize multiple distributed pressure and rebuild the more accurate impact pressure distribution.

Explosion resistance is one of the most important performances for all flameproof enclosures. Pressure piling requires the flameproof enclosures to withstand explosion pressure higher than the design pressure. In order to study the explosion parameters in a flameproof enclosure under pressure piling, two experimental setups were prepared based on the theoretical analysis of the mechanism of pressure piling. One setup simulated the condition that the interior of a flameproof box is isolated by a baffle with a small hole. Another setup simulated the condition that a large number of electrical components were installed inside an explosion-proof box. The experimental result showed that the explosion pressure increased significantly in a very short time under pressure piling. When an explosion occurred in a cavity, the pressure wave of the explosion propagated faster than the flame propagation, and the pressure wave was transmitted to another cavity through a gas channel between the two cavities. This resulted in the pre-pressurization of the combustible gas in another cavity. It was observed that the ignition time in the cavity with an ignition source, is the key factor for pressure piling.

Most large space debris has large residual angular momentum, and the de-tumbling and capturing operation can easily cause instability and failure of tracking satellites. Therefore, it is necessary to perform real-time dynamic parameter identification of space debris prior to the imminent de-tumbling and capture operation, thus improving the efficiency and success of active debris removal (ADR) missions. A method for identifying dynamic parameters based on the fusion of visual and inertial data is proposed. To obtain the inertial data, the inertial measurement units (IMU) with light markers were fixed on the debris surface by space harpoon, which has been experimentally proven in space, and the binocular vision was placed at the front of a tracking satellite to obtain coordinates of the light markers. A novel method for denoising inertial data is proposed, which will eliminate the interference from the space environment. Furthermore, based on the denoised data and coordinates of the light markers, the mass-center location is estimated. The normalized angular momentum is calculated using the Euler–Poinsot motion characteristics, and all active debris removal parameters are determined. Simulations with Gaussian noise and experiments in the controlled laboratory have been conducted, the results indicate that this method can provide accurate dynamic parameters for the ADR mission.

Microfluidic chips—in which chemical or biological fluid samples are mixed into linear or nonlinear concentration distribution profiles—have generated enormous enthusiasm of their ability to develop patterns for drug release and their potential toxicology applications. These microfluidic devices have untapped potential for varying concentration patterns by the use of one single device or by easy-to-operate procedures. To address this challenge, we developed a soft-lithography-fabricated microfluidic platform that enabled one single device to be used as a concentration maker, which could generate linear, bell-type, or even S-type concentration profiles by tuning the feed flow rate ratios of each independent inlet. Here, we present an FFRR (feed flow rate ratio) adjustment approach to generate tens of types of concentration gradient profiles with one single device. To demonstrate the advantages of this approach, we used a Christmas-tree-like microfluidic chip as the demo. Its performance was analyzed using numerical simulation models and experimental investigations, and it showed an excellent time response (~10 s). With on-demand flow rate ratios, the FFRR microfluidic device could be used for many lab-on-a-chip applications where flexible concentration profiles are required for analysis.

Multi-clearance is the main cause for the performance and reliability decline of complicated mechanical systems. The increased clearance could induce contacts and impacts in joints, and consequently affect control accuracy. A nonlinear dynamic model of planetary gears with multi-clearance coupling is proposed in the current study to investigate the mechanism of influence of clearance on the dynamic performance. In addition, the coupling relationship between radial clearance and backlash is integrated into the multi-body system dynamics. The vibration characteristics of planetary gears with the changes of rotational velocity, clearance size and inertia load are explored. The numerical simulation results show that there are complex coupling relations in planetary gear systems, due to the multi-clearance coupling. The phenomenon of system resonance may occur with the changes of rotational velocities and clearances’ sizes. Multi-clearance coupling can significantly increase the resonant response of planetary gear systems in empty-load or light-load states.

Background • Patients with prior cancer are generally exempt from cancer experiments. This research aims to describe the prevalence, clinical features, and effects of past malignancy among patients with chondrosarcoma. Methods • Chondrosarcoma patients diagnosed between 2010 to 2015 were collected from the SEER database. The propensity score matching method was used to reconcile the disparity in baseline attributes. Kaplan–Meier analysis was employed to explore the outcomes of prior cancer on overall survival. The proportional hazards assumption was used to certain whether the covariate matched the Cox regression model. The potential outliers were estimated by deviance residuals type. Results • A total of 1,721 unique individuals were collected, of those 284 (16.50%) patients had a history of cancer, with prostate cancer being commonly documented (n = 49, 17.25%). Approximately half of the previous tumors are diagnosed within 5 years before the diagnosis of chondrosarcoma. Chondrosarcoma patients with prior cancers have a lower survival rate than those without prior malignancy (P < .001). A multivariable Cox analysis reveals that past cancer is a distinct risk factor for lifespan (hazard ratio = 2.489, P < .001). Conclusion • This study initially discovered that chondrosarcoma patients with past cancer have a bad prognosis. Different types of past cancer have varying effects on survival. We urgently propose that cancer trial exclusion criteria be set specifically by cancer classification, rather than accepting the unchangeable criterion for default. [ABSTRACT FROM AUTHOR]