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BackgroundThe COVID-19 pandemic has significantly reduced physical activity (PA) levels and increased sedentary behavior (SB), which can lead to worsening physical fitness (PF). Children and adolescents may benefit from mobile health (mHealth) apps to increase PA and improve PF. However, the effectiveness of mHealth app–based interventions and potential moderators in this population are not yet fully understood. ObjectiveThis study aims to review and analyze the effectiveness of mHealth app–based interventions in promoting PA and improving PF and identify potential moderators of the efficacy of mHealth app–based interventions in children and adolescents. MethodsWe searched for randomized controlled trials (RCTs) published in the PubMed, Web of Science, EBSCO, and Cochrane Library databases until December 25, 2023, to conduct this meta-analysis. We included articles with intervention groups that investigated the effects of mHealth-based apps on PA and PF among children and adolescents. Due to high heterogeneity, a meta-analysis was conducted using a random effects model. The Cochrane Risk of Bias Assessment Tool was used to evaluate the risk of bias. Subgroup analysis and meta-regression analyses were performed to identify potential influences impacting effect sizes. ResultsWe included 28 RCTs with a total of 5643 participants. In general, the risk of bias of included studies was low. Our findings showed that mHealth app–based interventions significantly increased total PA (TPA; standardized mean difference [SMD] 0.29, 95% CI 0.13-0.45; P

This paper explores the impact of artificial intelligence and machine automation on productivity. It focuses on analyzing the production model of machinery automation based on Petri nets. Through the invariant analysis method, the article constructs a model and presents its structure as a correlation matrix. The study results show that the model has an error rate of only 2.26% and an accuracy of 90.14% in terms of operational performance. Regarding time performance, its training time is 3854 seconds and response time is 351 milliseconds, which are better than other algorithms. In the practical application of automotive parts production, the method significantly reduces the busy probability and blocking probability during order processing and material delivery, and also improves the equipment load rate, waiting rate and blocking rate in the production process. This indicates that the Petri net-based method of machine automation production has significant advantages in improving productivity and reducing costs.

Focusing on CNC process data, this paper provides an in-depth analysis, characterization and mining of macro machining processes by associating CAD and CAM models. The article introduces a Bayesian inference method to construct an association relationship between the manufacturing features of the query part and the macroscopic process of the manufactured part, which avoids the need for a direct similarity comparison between the geometry of the query part and the part to be manufactured. In addition, the study calculated the overall similarity between the query part and the CNC programming process data instances through the guidance of the process skeleton, thus realizing the precise evaluation from the CNC programming perspective. The algorithm for generating tool trajectories in multi-axis CNC programming is analyzed. By selecting representative surfaces and performing tool processing calculations, this study explores the process planning and tool parameter selection of usual parts of surfaces in multi-axis CNC programming machining. It optimizes the nonlinear error in tool trajectory processing by combining CAD/CAM technology. The results show that the optimized process proposed in this paper significantly improves the machining efficiency by 36.94%. In the cutting at tool corners, the maximum cutting force generated by the optimized machining process is only 190.3N, which is only 67.2% of the leading cutting force of the Cimatron process. In addition, when the engagement frequency is 780 Hz, the optimized process proposed in this paper has the smallest vibration amplitude, which is only 21.4% of the Cimatron strategy. Therefore, this study significantly improves the machining efficiency while ensuring the machining quality, which has important practical application value.

Reservoir damage is an important factor limiting the productivity of coalbed methane wells. In this paper, the coal seam in a coalbed methane producing area in the southeast edge of Ordos Basin is taken as the research object, and the types of reservoir damage in this block are analyzed through the composition test of coal samples and the comparison of production conditions, and the targeted solutions are given. The results show that the main types of reservoir damage in this block are solid plugging and water locking damage. The dissolution rate of acidic plugging removal working fluid with hydrochloric acid, hydrofluoric acid, acetic acid and hydrogen peroxide as main components for pulverized coal in this block reached 13.73%. After acidification, the permeability increased by 1.8~6.9 times, and the porosity increased by 0.35%~2.87%, indicating that the plugging removal working fluid system can effectively dredge the liquid seepage channel, reduce the seepage resistance and achieve the plugging removal effect.

CrN and diamond-like carbon (DLC) coatings are deposited on the surface of 431 stainless steel by the direct current magnetron sputtering technique. The surface morphology, micro-structure, hardness, friction, and wear properties of CrN, CrN/DLC and multi-layer composite DLC coatings are investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, nanoindentation tester, scratch tester, and friction and wear tester. The results show that the surface of the single CrN coating is very rough for the columnar crystal structure with preferred orientation. When it serves as inner transition layers to form the composite DLC coatings, the surface gets much smoother, with reduced defects. The friction and wear results indicate that the composite DLC coatings exhibit lower coefficients of friction, and better wear and corrosion resistance in dry friction, deionized water, and seawater. In the dry wear and friction process, the single CrN coating is easily worn out, and severe friction oxidation and furrow wear both appear with a friction coefficient of 0.48. But the friction coefficient of a CrN coating in seawater is reduced to 0.16, and friction oxidation and wear loss are further reduced with water lubrication. The CrN/DLC coating has excellent tribological performance in three test concoctions and has the lowest friction coefficient of 0.08 in seawater, which is related to the higher sp3 bond content, density (1.907 g/cm3) and high degree of amorphization, contributing to high hardness and a self-lubrication effect. However, due to the limited thickness of CrN/DLC (1.14 µm), it easily peels off and fails during friction and wear in different testing conditions. In multi-layer composite DLC coatings, there are more sp2 bonds with decreased amorphization, high enough thickness (4.02 µm), and increased bonding strength for the formation of different carbides and nitrides of chromium as transition layers, which gives rise to the further decreased average friction coefficient and the lowest wear loss. Therefore, the CrN coating alone has good wear resistance, and, as with the inner transition layer with a DLC coating, it can effectively improve the overall thickness and the bonding strength of the multi-layer films by optimizing the chemical compounds of DLC coatings. These results provide experimental support and reference for the design and selection of surface coatings for 431 stainless steels in different working conditions. [ABSTRACT FROM AUTHOR]

Epigallocatechin gallate (EGCG), a typical flavone-3-ol polyphenol containing eight free hydroxyl groups, is associated with a variety of bioactivities, such as antioxidant, anti-inflammatory, anti-cancer, and antibacterial activities. However, the poor bioavailability of EGCG restricts its use. In this review, we discuss the processes involved in the absorption and metabolism of EGCG, with a focus on its metabolic interactions with the gut microbiota. Next, we summarize the bioactivities of some key metabolites, describe the biotransformation of EGCG by different microorganisms, and discuss its catabolism by specific bacteria. A deeper understanding of the absorption, metabolism, and biotransformation of EGCG may enable its disease-preventive and therapeutic properties to be better utilized. This review provides a theoretical basis for further development and utilization of EGCG and its metabolites for improving the gut microbiota and physiological health. [ABSTRACT FROM AUTHOR]

Coalbed methane development primarily relies on hydraulic fracturing and drainage gas extraction processes. The intrusion of external fluids and long-term drainage and extraction contribute to the water blocking effect, which becomes one of the crucial factors affecting production capacity. In this study, the coal reservoir of a certain coalbed methane in Hancheng, Shaanxi Province, was selected as the research object. The experimental method was employed to comprehensively evaluate the correlation between factors such as coal sample moisture content, permeability, porosity, properties of external liquids, and water blocking damage. The results indicated that there was a positive correlation between coal sample moisture content, liquid surface tension, and water blocking damage. On the other hand, coal sample pore permeability characteristics, liquid contact angle with rock samples, and water blocking damage showed a negative correlation. Building upon the aforementioned research, an investigation into remedial measures for water blocking damage was conducted. Additionally, a chemical treatment study using the compound surfactant system JSS-1 as a water-blocking agent was performed to manage the water blocking effect. The results demonstrated that JSS-1 as a water-blocking agent significantly reduced the surface tension of the wellbore fluid and improved its wetting behavior on the coal-rock surface. The laboratory experiments confirmed the capability of JSS-1 in managing the water blocking effect.

Purpose: This study aimed to analyze the efficacy and safety of neoadjuvant and adjuvant immunotherapies for non-small cell lung cancer (NSCLC). Methods: Electronic literature searches were conducted in PubMed, OVID, Web of SCI, Embase, Cochrane Library, and the Chinese National Knowledge Infrastructure databases. The deadline for literature update and retrieval is February 16, 2024. Studies presented at meetings were also screened. Randomized controlled trials (RCTs) and single-arm trials were included, and the data were extracted according to the inclusion and exclusion criteria. Data analysis was performed using Stata (16.0) software. Results: A total of 5850 patients in 11 RCTs and 6 single-arm trial studies involving neoadjuvant and/or adjuvant immune checkpoint inhibitor (ICI)-based therapies were included. Regarding neoadjuvant therapy, the overall complication rate after surgery reached 35% (95% CI, 0.21-0.49). Higher rates of pathological complete response (OR = 7.83; 95% CI, 5.95-10.31; P <.001) and major pathological response (OR = 5.13; 95% CI, 3.56-7.40; P <.001) were found in the resectable NSCLC patients who received neoadjuvant therapy with ICIs combined with chemotherapy compared with patients treated with chemotherapy alone. Of note, compared with chemotherapy, neoadjuvant ICIs combined with chemotherapy significantly improved the overall survival (OS) (HR = 0.65; 95% CI, 0.52-0.82; P <.001) and event-free survival (EFS) (HR = 0.59; 95% CI, 0.52-0.67; P <.001) in patients with resectable NSCLC. Regarding adjuvant therapy, a lower risk of disease progression or death (HR = 0.78; 95% CI, 0.69-0.90; P <.001) was found in the adjuvant ICI group compared with the adjuvant chemotherapy-alone group. In terms of safety, perioperative immunotherapy combined with chemotherapy did not increase toxicity compared with chemotherapy alone. Conclusion: In patients with resectable NSCLC, perioperative immunotherapy was safe and efficacious. Perioperative immunotherapy combined with chemotherapy improved the pathologic response and EFS/DFS/OS over chemotherapy alone without increasing toxicity. [ABSTRACT FROM AUTHOR]