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1.
BMC Musculoskelet Disord ; 25(1): 538, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38997705

ABSTRACT

BACKGROUND: How to quickly read and interpret intraoperative ultrasound (IOUS) images of patients with degenerative cervical myelopathy (DCM) to obtain meaningful information? Few studies have systematically explored this topic. PURPOSE: To systematically and comprehensively explore the IOUS characteristics of patients with DCM. MATERIALS AND METHODS: This single-center study retrospectively included patients with DCM who underwent French-door laminoplasty (FDL) with IOUS guidance from October 2019 to March 2022. One-way ANOVA and Pearson's /Spearman's correlation analysis were used to analyze the correlations between the cross-sectional area of the spinal cord (SC) and individual characteristics; the relationships between the morphology, echogenicity, pulsation, decompression statuses, compression types of SC, location of the spinal cord central echo complex (SCCEC) and the disease severity (the preoperative Japanese Orthopedic Association score, preJOA score); the difference of the spinal cord pulsation amplitude(SCPA) and the SCCEC forward movement rate (FMR) between the compressed areas(CAs) and the non-compressed areas (NCAs). RESULTS: A total of 38 patients were successfully enrolled (30 males and 8 females), and the mean age was 57.05 ± 10.29 (27-75) years. The cross-sectional area of the SC was negatively correlated with age (r = - 0.441, p = 0.006). The preJOA score was significantly lower in the heterogeneous group than in the homogeneous group (P < 0.05, p = 0.005). The hyperechoic area (HEA) was negatively while the SCCEC FMR was positively correlated with the preJOA score (r = - 0.334, p = 0.020; r = 0.286, p = 0.041). The SCCEC FMR and SCPA in CAs were significantly greater than those in NCAs (p < 0.05, p = 0.007; P < 0.001, P = 0.000). CONCLUSION: The cross-sectional area of the SC decreases with age in adults. More changes in intramedullary echogenicity and less moving forward of the SCCEC often indicate poor SC status, and the SCCEC FMR and SCPA are more pronounced in CAs.


Subject(s)
Cervical Vertebrae , Laminoplasty , Humans , Male , Female , Middle Aged , Aged , Retrospective Studies , Cervical Vertebrae/surgery , Cervical Vertebrae/diagnostic imaging , Adult , Laminoplasty/methods , Spinal Cord Diseases/surgery , Spinal Cord Diseases/diagnostic imaging , Ultrasonography , Spinal Cord Compression/surgery , Spinal Cord Compression/diagnostic imaging
2.
Neural Netw ; 178: 106467, 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38908168

ABSTRACT

In recent years, the research on transferable feature-level adversarial attack has become a hot spot due to attacking unknown deep neural networks successfully. But the following problems limit its transferability. Existing feature disruption methods often focus on computing feature weights precisely, while overlooking the noise influence of feature maps, which results in disturbing non-critical features. Meanwhile, geometric augmentation algorithms are used to enhance image diversity but compromise information integrity, which hamper models from capturing comprehensive features. Furthermore, current feature perturbation could not pay attention to the density distribution of object-relevant key features, which mainly concentrate in salient region and fewer in the most distributed background region, and get limited transferability. To tackle these challenges, a feature distribution-aware transferable adversarial attack method, called FDAA, is proposed to implement distinct strategies for different image regions in the paper. A novel Aggregated Feature Map Attack (AFMA) is presented to significantly denoise feature maps, and an input transformation strategy, called Smixup, is introduced to help feature disruption algorithms to capture comprehensive features. Extensive experiments demonstrate that scheme proposed achieves better transferability with an average success rate of 78.6% on adversarially trained models.

3.
Environ Sci Technol ; 58(26): 11578-11586, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38899536

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) are the primary organic carbons in soot. In addition to PAHs with even carbon numbers (PAHeven), substantial odd-carbon PAHs (PAHodd) have been widely observed in soot and ambient particles. Analyzing and understanding the photoaging of these compounds are essential for assessing their environmental effects. Here, using laser desorption ionization mass spectrometry (LDI-MS), we reveal the substantially different photoreactivity of PAHodd from PAHeven in the aging process and their MS detection through their distinct behaviors in the presence and absence of elemental carbon (EC) in soot. During direct photooxidation of organic carbon (OC) alone, the PAHeven are oxidized more rapidly than the PAHodd. However, the degradation of PAHodd becomes preponderant over PAHeven in the presence of EC during photoaging of the whole soot. All of these observations are proposed to originate from the more rapid hydrogen abstraction reaction from PAHodd in the EC-photosensitized reaction, owing to its unique structure of a single sp3-hybridized carbon site. Our findings reveal the photoreactivity and reaction mechanism of PAHodd for the first time, providing a comprehensive understanding of the oxidation of PAHs at a molecular level during soot aging and highlight the enhanced effect of EC on PAHodd ionization in LDI-MS analysis.


Subject(s)
Carbon , Polycyclic Aromatic Hydrocarbons , Soot , Polycyclic Aromatic Hydrocarbons/chemistry , Carbon/chemistry , Soot/chemistry , Photochemical Processes , Oxidation-Reduction , Photochemistry
4.
Stem Cells ; 42(8): 752-762, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38829368

ABSTRACT

Bone marrow mesenchymal stem cells (BMSCs) possess the potential to differentiate into cartilage cells. Long noncoding RNA (lncRNAs) urothelial carcinoma associated 1 (UCA1) has been confirmed to improve the chondrogenic differentiation of marrow mesenchymal stem cells (MSCs). Herein, we further investigated the effects and underlying mechanisms of these processes. The expression of UCA1 was positively associated with chondrogenic differentiation and the knockdown of UCA1 has been shown to attenuate the expression of chondrogenic markers. RNA pull-down assay and RNA immunoprecipitation showed that UCA1 could directly bind to PARP1 protein. UCA1 could improve PARP1 protein via facilitating USP9X-mediated PARP1 deubiquitination. Then these processes stimulated the NF-κB signaling pathway. In addition, PARP1 was declined in UCA1 knockdown cells, and silencing of PARP1 could diminish the increasing effects of UCA1 on the chondrogenic differentiation from MSCs and signaling pathway activation. Collectively, these outcomes suggest that UCA1 could act as a mediator of PARP1 protein ubiquitination and develop the chondrogenic differentiation of MSCs.


Subject(s)
Cell Differentiation , Chondrogenesis , Mesenchymal Stem Cells , Poly (ADP-Ribose) Polymerase-1 , RNA, Long Noncoding , Ubiquitination , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Mesenchymal Stem Cells/metabolism , Mesenchymal Stem Cells/cytology , Humans , Cell Differentiation/genetics , Chondrogenesis/genetics , Poly (ADP-Ribose) Polymerase-1/metabolism , Poly (ADP-Ribose) Polymerase-1/genetics , Signal Transduction , Bone Marrow Cells/metabolism , Bone Marrow Cells/cytology , NF-kappa B/metabolism
5.
Sci Rep ; 14(1): 11259, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38755222

ABSTRACT

As the terminal of the power system, the distribution network is the main area where failures occur. In addition, with the integration of distributed generation, the traditional distribution network becomes more complex, rendering the conventional fault location algorithms based on a single power supply obsolete. Therefore, it is necessary to seek a new algorithm to locate the fault of the distributed power distribution network. In existing fault localization algorithms for distribution networks, since there are only two states of line faults, which can usually be represented by 0 and 1, most algorithms use discrete algorithms with this characteristic for iterative optimization. Therefore, this paper combines the advantages of the particle swarm algorithm and genetic algorithm and uses continuous real numbers for iteration to construct a successive particle swarm genetic algorithm (SPSO-GA) different from previous algorithms. The accuracy, speed, and fault tolerance of SPSO-GA, discrete particle swarm Genetic algorithm, and artificial fish swarm algorithm are compared in an IEEE33-node distribution network with the distributed power supply. The simulation results show that the SPSO-GA algorithm has high optimization accuracy and stability for single, double, or triple faults. Furthermore, SPSO-GA has a rapid convergence velocity, requires fewer particles, and can locate the fault segment accurately for the distribution network containing distorted information.

6.
Sci Rep ; 14(1): 12299, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38811744

ABSTRACT

To reduce the local scour around the spur dike, the U-shaped collar is proposed in this study. The influence of the collar's length, width, and porosity on the local scour reduction in clear water is studied by model tests and numerical simulations. Experimental studies show that the collar has a significant effect on reducing the local scour. The location of the maximum scour depth of the spur dike moves downstream. The width of the collar has the greatest impact on the reduction effect among the three selected factors, followed by the porosity and the length. Local scour reduction efficiency of the collar can reach 56.9%. Based on the regression analysis of the range and variety, a formula for predicting the reduction effect around the spur dike is put forward, and the deviation between the values by formula and that in experiments are within ± 4%. The characteristics of the flow field around the spur dike under constant conditions with a collar are studied via numerical simulation. The numerical simulation results show that compared to the case without collar, the flow velocities around the spur dike in cases with permeable collar and solid collar reduced by 45% and 25%, respectively, and the shear stresses reduced by 20% and 28.6%, respectively. The results of this study can provide a reference for local scour reduction using the solid collar or collar made of permeable materials such as gabions.

7.
Clin Oral Investig ; 28(5): 292, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38693418

ABSTRACT

OBJECTIVES: Exposure to aerosol particles generated from tooth grinding has a negative impact on the health of dental personnel. The aim of this study was to quantitatively analyze the impact of indoor relative humidity (IRH) on the deposition of these suspended particles in a well-controlled dental environment. MATERIALS AND METHODS: In this study, a humidity control system was employed to effectively regulate and maintain indoor relative humidity (IRH). A novel computer-assisted numerical control system was developed to pre-treat the molar specimens, and accurately simulate clinical tooth grinding procedures. Each procedure was performed in triplicate, with an online real-time particle counter (ORPC; TR-8301, TongrenCo.) measuring aerosol production. All testing devices were controlled remotely. The data obtained were statistically analyzed using descriptive statistics and non-parametric tests (Kruskal-Wallis/ Dunn's post hoc test with Bonferroni correction, p < 0.05). RESULTS: The findings showed that with increasing IRH, the maximum peak concentration of aerosol particles decreased by 397% from 6.51 × 107 particles/m3 at 30% to 1.64 × 107 particles/m3 at 80%. The Kruskal-Wallis test results indicated a statistically significant effect of IRH on the aerosol increment (p < 0.05). CONCLUSIONS: Increasing the IRH level can effectively promote the deposition of aerosol particles, with a return to baseline within 15 min after reaching 60% or above. CLINICAL RELEVANCE: Our study suggested that maintaining IRH above 70% during the cleaning process, allowing natural recovery to ambient humidity levels within 15 min after cleaning, and taking basic precautions, may lead to an adequate reduction in the possible health risks of aerosol contamination.


Subject(s)
Aerosols , Air Pollution, Indoor , Humidity , Humans , Air Pollution, Indoor/analysis
8.
J Mol Model ; 30(3): 69, 2024 Feb 13.
Article in English | MEDLINE | ID: mdl-38349467

ABSTRACT

CONTEXT: In order to study the effect of ultra-precision machining on the surface quality of hydroxyapatite semiconductor materials as well as the material removal mechanism of hydroxyapatite, the mechanical polishing behaviors of hydroxyapatite at different polishing depths were studied by molecular dynamics method. The results show that the subsurface damage of hydroxyapatite increases with increasing polishing depth. The polishing temperature and the polishing force showed a positive correlation with the polishing depth, and the variation of the polishing force was related to the accumulation-release effect of the potential energy of hydroxyapatite material. In addition, the variation of stresses in hydroxyapatite during polishing is mainly influenced by the thermal softening effect. With a smaller polishing depth, the hydroxyapatite semiconductor material has fewer structural defects, fewer atoms undergoing phase transitions, lower surface roughness, and better surface quality. Therefore, to ensure the long-lasting service life of hydroxyapatite semiconductor materials, a small polishing depth should be used in ultra-precision machining. Additionally, this study also provides a theoretical reference for future research on the mechanical properties of hydroxyapatite-based composites. METHODS: A Large-Scale Atomic/Molecular Parallel Simulator (LAMMPS) was utilized to perform molecular dynamics simulations. The output was visualized and analyzed by the Open Visualization Tools (OVITO) software. The intermolecular interactions were described by the polymer consistent force-field and the 12/6 Lennard-Jones potential functions. The workpiece was polished under a micro-canonical ensemble with the temperature settled at 300 K. Periodic boundary conditions were adopted and the velocity-Verlet algorithm was used to integrate the atomic motion with a timestep of 0.1 femtoseconds (fs).

9.
Cryobiology ; 114: 104866, 2024 03.
Article in English | MEDLINE | ID: mdl-38367795

ABSTRACT

The effect of a magnetic field on condensed droplet freezing and frost formation was investigated using visualized experimental devices in this study. The size, shape, freezing time of droplets, and frost shape on the magnetic field considerably differ from those on the nonmagnetic surface. Moreover, the magnetic field could suppress droplet freezing and frost formation. The magnetic field suppression effect on droplet freezing and frost formation was analyzed according to the polarity characteristics of water molecules.


Subject(s)
Cryopreservation , Water , Freezing , Cryopreservation/methods
10.
Clin Oral Investig ; 28(1): 120, 2024 Jan 27.
Article in English | MEDLINE | ID: mdl-38280059

ABSTRACT

OBJECTIVES: In this study, we investigated the dispersion patterns of aerosols and droplets in dental clinics and developed a suction device to evaluate its effectiveness in reducing aerosols during dental procedures. MATERIALS AND METHODS: Firstly, the continuous images of oral aerosols and droplets were photographed with a high-speed camera, and the trajectories of these particles were recognized and processed by Image J to determine key parameters affecting particle dispersion: diffusion velocity, distance, and angle. Secondly, based on the parameter data, the flow field of aerosol particles around the oral cavity was simulated using computational fluid dynamics (CFD), and the flow field under adsorption conditions was simulated to demonstrate the aerodynamic characteristics and capture efficiencies of the single-channel and three-channel adsorption ports at different pressures. Finally, according to the simulated data, a three-channel suction device was developed, and the capture efficiency of the device was tested by the fluorescein tracer method. RESULTS: The dispersion experimental data showed that aerosol particles' maximum diffusion velocity, distance, and angle were 6.2 m/s, 0.55 m, and 130°, respectively. The simulated aerosol flow-field distribution was consistent with the aerosol dispersion patterns. The adsorption simulation results showed that the outlet flow rate of single-channel adsorption was 184.5 L/s at - 350 Pa, and the aerosol capture efficiency could reach 79.4%. At - 350 Pa and - 150 Pa, the outlet flow rate of three-channel adsorption was 228.9 L/s, and the capture efficiency was 99.23%. The adsorption experimental data showed that the capture efficiency of three-channel suction device was 97.71%. CONCLUSIONS: A three-channel suction device was designed by simulations and experiments, which can capture most aerosols in the dental clinic and prevent them from spreading. CLINICAL RELEVANCE: Using three-channel suction devices during oral treatment effectively reduces the spread of oral aerosols, which is essential to prevent the spread of epidemics and ensure the health and safety of patients and dental staff.


Subject(s)
Aerosols , Humans , Computer Simulation
11.
Int Dent J ; 74(4): 876-883, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38238210

ABSTRACT

INTRODUCTION: During dental treatment procedures ultrasonic scalers generate droplets containing microorganisms such as bacteria and viruses. Hence, it is necessary to study the dynamic properties of generated droplets in order to investigate the risks associated with the spread of infection. The aim of this study was to visualise the flow state of droplets and to evaluate the impact of droplets generated during the use of an ultrasonic scaler during an oral surgical procedure. METHODS: We studied the spatial flow of liquid droplets through a combination of imaging and numeric simulation of a simulated dental treatment processes. First, we photographed the real time images of the ultrasonic scaler and evaluated the images using image-processing software Image J to visualise the flow of liquid droplets. Finally we simulated the flow process of liquid droplets by using the initial velocity of droplet splashing and the angle of the obtained information using computerised fluid dynamics technology. RESULTS: Under different working conditions, the droplet particle splashing velocity, maximum height, and spray angle varied, but the particle trajectory was generally parabolic. The maximum droplet velocity varied between 3.56 and 8.56 m/s, and the splashing height was between 40 and 110 mm. CONCLUSIONS: During risk assessment of an ultrasonic scaler usage, difficulties arise due to the insufficient research on droplet velocity and distribution. This study aims to address this gap by visualising the flow trajectories of droplets generated by ultrasonic scalers. The obtained data will assist in developing more effective interventions based on spatial and temporal distribution of droplets. This provides a new approach for droplet particle research and offers new strategies for public health prevention and control.


Subject(s)
Dental Scaling , Humans , Dental Scaling/instrumentation , Hydrodynamics , Image Processing, Computer-Assisted/methods , Ultrasonics/instrumentation , Computer Simulation
12.
Eur Radiol ; 34(2): 736-744, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37581658

ABSTRACT

OBJECTIVE: To investigate the feasibility and effectiveness of applying intraoperative ultrasound (IOUS) to evaluate spinal canal expansion in patients undergoing French-door cervical laminoplasty (FDCL). MATERIALS AND METHODS: Twenty-five patients who underwent FDCL for multilevel degenerative cervical myelopathy were prospectively recruited. Formulae describing the relationship between laminoplasty opening angle (LOA) and laminoplasty opening size, the increase in sagittal canal diameter and the spinal canal area were deduced with trigonometric functions. The LOA was measured with IOUS imaging during surgery, and other spinal canal parameters were assessed. Actual spinal canal enlargement was verified on postoperative CT images. Linear correlation analysis and Bland‒Altman analysis were used to evaluate correlation and agreement between the intraoperative and postoperative measurements. RESULTS: The LOA at C5 measured with IOUS was 27.54 ± 3.12°, and it was 27.23 ± 3.02° on postoperative CT imaging. Linear correlation analysis revealed a significant correlation between IOUS and postoperative CT measurements (r = 0.88; p < 0.01). Bland-Altman plots showed good agreement between these two methods, with a mean difference of 0.30°. For other spinal canal expansion parameter measurements, correlation analysis showed a moderate to a high degree of correlation (p < 0.01), and Bland-Altman analysis indicated good agreement. CONCLUSION: In conclusion, during the French-door cervical laminoplasty procedure, application of IOUS can accurately evaluate spinal canal expansion. This innovative method may be helpful in improving surgical accuracy by enabling the operator to measure and determine canal enlargement during surgery, leading to ideal clinical outcomes and fewer postoperative complications. CLINICAL RELEVANCE STATEMENT: The use of intraoperative ultrasonography to assess spinal canal expansion following French-door cervical laminoplasty may improve outcomes for patients undergoing this procedure by providing more accurate measurements of spinal canal expansion. KEY POINTS: • Spinal canal expansion after French-door cervical laminoplasty substantially influences operative prognosis; insufficient or excessive lamina opening may result in unexpected outcomes. • Prediction of spinal canal expansion during surgery was previously impracticable, but based on this study, intraoperative ultrasonography offers an innovative approach and strongly agrees with postoperative CT measurement. • Since this is the first research to offer real-time canal expansion guidance for cervical laminoplasty, it may improve the accuracy of the operation and produce ideal clinical outcomes with fewer postoperative complications.


Subject(s)
Laminoplasty , Spinal Cord Diseases , Humans , Laminoplasty/adverse effects , Laminoplasty/methods , Cervical Vertebrae/diagnostic imaging , Cervical Vertebrae/surgery , Spinal Canal/diagnostic imaging , Spinal Canal/surgery , Ultrasonography , Postoperative Complications/etiology , Treatment Outcome , Spinal Cord Diseases/diagnostic imaging , Spinal Cord Diseases/surgery , Spinal Cord Diseases/complications , Retrospective Studies
13.
Eur Radiol ; 34(4): 2297-2309, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37707550

ABSTRACT

OBJECTIVES: To evaluate the ability of intraoperative CEUS to predict neurological recovery in patients with degenerative cervical myelopathy (DCM). METHODS: Twenty-six patients with DCM who underwent laminoplasty and intraoperative ultrasound (IOUS) were included in this prospective study. The modified Japanese Orthopaedic Association (mJOA) scores and MRI were assessed before surgery and 12 months postoperatively. The anteroposterior diameter (APD), maximum spinal cord compression (MSCC), and area of signal changes in the cord at the compressed and normal levels were measured and compared using MRI and IOUS. Conventional blood flow and CEUS indices (time to peak, ascending slope, peak intensity (PI), and area under the curve (AUC)) at different levels during IOUS were calculated and analysed. Correlations between all indicators and the neurological recovery rate were evaluated. RESULTS: All patients underwent IOUS and intraoperative CEUS, and the total recovery rate was 50.7 ± 33.3%. APD and MSCC improved significantly (p < 0.01). The recovery rate of the hyperechoic lesion group was significantly worse than that of the isoechoic group (p = 0.016). 22 patients were analysed by contrast analysis software. PI was higher in the compressed zone than in the normal zone (24.58 ± 3.19 versus 22.43 ± 2.39, p = 0.019). ΔPI compress-normal and ΔAUC compress-normal of the hyperechoic lesion group were significantly higher than those of the isoechoic group (median 2.19 versus 0.55, p = 0.017; 135.7 versus 21.54, p = 0.014, respectively), and both indices were moderately negatively correlated with the recovery rate (r = - 0.463, p = 0.030; r = - 0.466, p = 0.029). CONCLUSIONS: Signal changes and microvascular perfusion evaluated using CEUS during surgery are valuable predictors of cervical myelopathy prognosis. CLINICAL RELEVANCE STATEMENT: In the spinal cord compression area of degenerative cervical myelopathy, especially in the hyperechoic lesions, intraoperative CEUS showed more significant contrast agent perfusion than in the normal area, and the degree was negatively correlated with the neurological prognosis. KEY POINTS: • Recovery rates in patients with hyperechoic findings were lower than those of patients without lesions detected during intraoperative ultrasound. • The peak intensity of CEUS was higher in compressed zones than in the normal parts of the spinal cord. • Quantitative CEUS comparisons of the peak intensity and area under the curve at the compressed and normal levels of the spinal cord revealed differences that were inversely correlated to the recovery rate.


Subject(s)
Cervical Cord , Spinal Cord Compression , Spinal Cord Diseases , Humans , Spinal Cord Compression/pathology , Prospective Studies , Cervical Cord/diagnostic imaging , Cervical Cord/surgery , Cervical Cord/pathology , Cervical Vertebrae/diagnostic imaging , Cervical Vertebrae/surgery , Cervical Vertebrae/pathology , Spinal Cord/pathology , Spinal Cord Diseases/diagnostic imaging , Spinal Cord Diseases/surgery , Spinal Cord Diseases/pathology , Magnetic Resonance Imaging , Treatment Outcome
14.
Sci Prog ; 106(4): 368504231211660, 2023.
Article in English | MEDLINE | ID: mdl-38058131

ABSTRACT

To investigate the fatigue crack propagation behavior of high-strength bolts for high-speed train brake discs, the fatigue crack propagation of high-strength bolts with initial defects under various load ratios was numerically simulated and experimentally verified based on fracture mechanics in this paper. Firstly, the fracture mechanics model of a three-dimensional hexahedral mesh with initial root defects was established using ABAQUS-FRANC3D interactive technology. Then the stress intensity factor (SIF) of the crack front was calculated by the stress superposition of the crack surface to simulate the coupling effect of preload and axial cyclic load. Based on it, fatigue crack propagation was simulated. Finally, the corresponding fatigue experiments on prefabricated crack bolts were carried out. The results show that mode I cracks dominate in the process of crack propagation. The stable crack propagation zones of the fractured high-strength bolts all show a semi-elliptical cross-section. The SIF of the crack front decreases with the increase of the load ratio, thus making the crack propagation life increase with the increase of the load ratio. The experimental outcomes are in great agreement with the simulation results, which verify that the numerical simulation method can effectively and accurately evaluate the fatigue life of high-strength bolts with initial defects and provides an effective means for predicting the fatigue crack propagation life of the same type high-strength bolts in engineering applications.

15.
Sci Rep ; 13(1): 20711, 2023 Nov 24.
Article in English | MEDLINE | ID: mdl-38001332

ABSTRACT

Based on existing researches, field drillings and numerical simulations are carried out in this paper to analyze the problems of subsidence control in the goaf of multi-layer inclined coal seam. Midas/GTS NX is used to build a three-dimensional calculation model of the goaf. A new method of using borehole data to check simulation parameters is proposed. The whole process of goaf excavation, construction of roadbed (pile foundation) and grouting treatment is analyzed. Analysis theory of different subgrade construction schemes and grouting treatment process on goaf is established. Response characteristics of displacement and equivalent stress and strain of goaf in multilayer inclined coal seam are obtained. A new method for analyzing the characteristics of the stress and deformation of the rock strata before and after grouting in the goaf under the conditions of different foundation schemes on the surface is provided in this research.

16.
Medicine (Baltimore) ; 102(44): e35758, 2023 Nov 03.
Article in English | MEDLINE | ID: mdl-37933069

ABSTRACT

BACKGROUND: We used bibliometric methods to evaluate publications on the role of nutrition in sarcopenic obesity and analyzed the current situation and developmental trends over the past 2 decades. METHODS: Publications from 2002 to 2022 related to the role of nutrition in sarcopenic obesity were extracted from the Web of Science Core Collection database. CiteSpace, VOSviewer, and the Bibliometrix R package were applied to build relevant network diagrams. RESULTS: One thousand ninety-four articles from 64 countries were included. The annual number of publications in this field has shown an intense growth trend. The University of Alberta, Yonsei University, and Korea University are the major research institutions. Clinical Nutrition has published the most papers on the role of nutrition in sarcopenic obesity, and the American Journal of Clinical Nutrition is the most co-cited journal. A total of 5834 authors conducted the relevant studies. Yves Boirie has published the most papers in this field, and AJ Cruz-Jentoft is the most co-cited author. CONCLUSION: This is the first bibliometric study of the role of nutrition in sarcopenic obesity. This study systematically summarizes the research hotspots and development directions in this field, and provides a reference for scholars studying the role of nutrition in sarcopenic obesity.


Subject(s)
Sarcopenia , Humans , Research , Bibliometrics , Databases, Factual , Obesity
17.
Nanomicro Lett ; 16(1): 34, 2023 Nov 29.
Article in English | MEDLINE | ID: mdl-38019305

ABSTRACT

Implantable hydrogel-based bioelectronics (IHB) can precisely monitor human health and diagnose diseases. However, achieving biodegradability, biocompatibility, and high conformality with soft tissues poses significant challenges for IHB. Gelatin is the most suitable candidate for IHB since it is a collagen hydrolysate and a substantial part of the extracellular matrix found naturally in most tissues. This study used 3D printing ultrafine fiber networks with metamaterial design to embed into ultra-low elastic modulus hydrogel to create a novel gelatin-based conductive film (GCF) with mechanical programmability. The regulation of GCF nearly covers soft tissue mechanics, an elastic modulus from 20 to 420 kPa, and a Poisson's ratio from - 0.25 to 0.52. The negative Poisson's ratio promotes conformality with soft tissues to improve the efficiency of biological interfaces. The GCF can monitor heartbeat signals and respiratory rate by determining cardiac deformation due to its high conformability. Notably, the gelatin characteristics of the biodegradable GCF enable the sensor to monitor and support tissue restoration. The GCF metamaterial design offers a unique idea for bioelectronics to develop implantable sensors that integrate monitoring and tissue repair and a customized method for endowing implanted sensors to be highly conformal with soft tissues.

18.
Nat Commun ; 14(1): 6263, 2023 Oct 07.
Article in English | MEDLINE | ID: mdl-37805528

ABSTRACT

Hydrogen peroxide (H2O2) electrosynthesis through oxygen reduction reaction (ORR) is drawing worldwide attention, whereas suffering seriously from the sluggish oxygen evolution reaction (OER) and the difficult extraction of thermodynamically unstable H2O2. Herein, we present an electrosynthesis protocol involving coupling ORR-to-H2O2 with waste polyethylene terephthalate (PET) upcycling and the first H2O2 conversion strategy. Ni-Mn bimetal- and onion carbon-based catalysts are designed to catalyze ORR-to-H2O2 and ethylene glycol electrooxidation with the Faradaic efficiency of 97.5% (H2O2) and 93.0% (formate). This electrolysis system runs successfully at only 0.927 V to achieve an industrial-scale current density of 400 mA cm-2, surpassing all reported H2O2 electrosynthesis systems. H2O2 product is upgraded through two downstream routes of converting H2O2 into sodium perborate and dibenzoyl peroxide. Techno-economic evolution highlights the high gross profit of the ORR || PET upcycling protocol over HER || PET upcycling and ORR || OER. This work provides an energy-saving methodology for the electrosynthesis of H2O2 and other chemicals.

19.
Sci Rep ; 13(1): 14567, 2023 Sep 04.
Article in English | MEDLINE | ID: mdl-37667025

ABSTRACT

To investigate the effect of initial cracks on the fatigue performance of high-strength bolts for high-speed train brake discs, the fatigue crack propagation behavior of high-strength bolts under the coupling action of preload and dynamic fatigue load was investigated experimentally and numerically based on the theory of linear elastic fracture mechanics. Firstly, fatigue tests of high-strength bolts with initial crack defects were carried out, and then a three-dimensional accurate numerical model with the hexahedral mesh for a bolt-nut was established by MATLAB, and the fatigue crack propagation behaviors were investigated using ABAQUS-FRANC3D interactive technology. In this paper, the effects of the initial crack state, the bolt preload, the axial excitation load, and the friction coefficient of the screw pair on crack propagation life were emphatically studied, and the simulated crack propagation trajectory and crack propagation life agreed well with the experimental results. The findings indicated that 0°-oriented cracks beginning at the maximum principal stress were predicted to have the shortest fatigue life. The crack propagation life was sensitive to the initial crack size, the coefficient of initial crack geometry, and the bolt preload, but not to the friction coefficient of the screw pair. Furthermore, when evaluating the effect of fatigue load on crack propagation, the load ratio, the mean load, and the load range should all be considered.

20.
J Mater Sci Mater Med ; 34(10): 46, 2023 Sep 21.
Article in English | MEDLINE | ID: mdl-37735283

ABSTRACT

Poor selectivity, low bioavailability and serious systemic side-effects have limited the application of traditional chemotherapy method for treatment of prostate cancer. Stimuli-responsive drug delivery systems for chemotherapy are mainly based on the unique characteristics of tumor microenvironment. In this study, the GSH-sensitive poly-TTG-SS@DTX NPs (DTX-loaded poly-Tetraethylene glycol nanoparticles) were designed and synthesized, which were characterized with nanosized diameter (92.8 ± 2.5 nm) and negatively charged surface charge (-24.7 ± 5.56 mV). Experiments in vitro showed that poly-TTG-SS@DTX NPs had good compatibility to healthy cells and strong anti-tumor effect because of rapid and sustained drug release of DTX from poly-TTG-SS@DTX NPs under the tumor-microenvironment condition. The cellular activity remained greater than 90% when the concentration of poly-TTG-SS NPs reached as high as 100 µg/mL treated on healthy cells. The killing effect of DTX loading NPs group on C4-2 cells was stronger than that of free anti-tumor drug and free DTX combined with the blank nano-carrier (25.21% vs 19.93% vs 20.96%). In conclusion, poly-TTG-SS@DTX NPs may provide a new therapeutic strategy for the chemotherapy of prostate cancer.


Subject(s)
Prostatic Neoplasms , Tumor Microenvironment , Male , Humans , Prostatic Neoplasms/drug therapy , Excipients , Drug Delivery Systems , Biological Availability
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