Search Results (2,919)

The COVID-19 pandemic triggered unprecedented economic disruptions, raising critical questions about the resilience and adaptability of macroeconomic productivity across countries. This study examines the impact of COVID-19 on macroeconomic efficiency and productivity dynamics in 37 OECD countries using quarterly data from 2018Q1 to 2024Q4. By employing a Slack-Based Measure Data Envelopment Analysis (SBM-DEA) and the Malmquist Productivity Index (MPI), we decompose total factor productivity (TFP) into efficiency change (EC) and technological change (TC) across three periods: pre-pandemic, during-pandemic, and post-pandemic. Our framework incorporates both desirable (GDP) and undesirable outputs (inflation, unemployment, housing price inflation, and interest rate distortions), offering a multidimensional view of macroeconomic efficiency. Results show broad but uneven productivity gains, with technological progress proving more resilient than efficiency during the pandemic. Post-COVID recovery trajectories diverged, reflecting differences in structural adaptability and innovation capacity. Regression analysis reveals that stringent lockdowns in 2020 were associated with lower productivity in 2023–2024, while more adaptive policies in 2021 supported long-term technological gains. These findings highlight the importance of aligning crisis response with forward-looking economic strategies and demonstrate the value of DEA-based methods for evaluating macroeconomic performance beyond GDP. Full article

Current rehabilitation protocols for transitioning patients to late-stage recovery, evaluating return-to-play (RTP) clearance, and assessing tendon characteristics exhibit significant heterogeneity. Clinicians frequently interpret and apply research findings based on individual philosophies, resulting in varied RTP criteria and performance expectations. Despite medical clearance, patients recovering from Achilles tendon (AT) injuries often exhibit persistent impairments in muscle volume, tendon structure, and force-generating capacity. Inconsistencies in assessment frameworks, compounded by a lack of quantitative data and the utilization of specific metrics to quantify certain strength characteristics (endurance, maximal, explosive, etc.) and standardized protocols, hinder optimal functional recovery of the plantar flexors during the final stages of rehabilitation and RTP. With this in mind, the aim of this integrative review was to provide an overview of AT rehabilitation, with particular critique around mid-stage strengthening and the use of the heel-raise assessment in milestoning rehabilitation progress. From this critique, new perspectives in mid-stage strengthening are suggested and future research directions identified. Full article

Flexible energy sources such as electric vehicles and the battery energy storage systems of intelligent distribution systems can provide system-wide auxiliary services such as frequency regulation for power systems. This paper proposes an optimal method for operating the local energy community that is based on two-stage scheduling. Firstly, the basic concepts of the local energy community and flexible service are introduced in detail. Taking LEC as the reserve unit of artificial frequency recovery, an energy information interaction model among LEC, balance service providers, and the power grid is established. Then, a two-stage scheduling framework is proposed to ensure the rationality and economy of community energy scheduling. In the first stage, day-ahead scheduling uses the energy community management center to predict the up/down flexibility capacity that LEC can provide by adjusting the BESS control parameters. In the second stage, real-time scheduling aims at maximizing community profits and scheduling LEC based on the allocation and activation of standby flexibility determined in real time. Finally, the correctness of the two-stage scheduling framework is verified through a case study. The results show that the control parameters used in the day-ahead stage can significantly affect the real-time profitability of LEC, and that LEC benefits more in the case of low BESS utilization than in the case of high BESS utilization and non-participation in frequency recovery reserve. Full article

Skeletal muscle regeneration depends on muscle stem cells, which give rise to myoblasts that drive muscle growth, repair, and maintenance. In bats—the only mammals capable of powered flight—these processes must also sustain contractile performance under extreme mechanical and metabolic stress. However, the cellular and molecular mechanisms underlying bat muscle physiology remain largely unknown. To enable mechanistic investigation of these traits, we established the first myoblast cell lines from the pectoralis muscle of Pteronotus mesoamericanus, a highly maneuverable aerial insectivore. Using both spontaneous immortalization and exogenous hTERT/CDK4 gene overexpression, we generated two stable cell lines that retain proliferative capacity and differentiate into contractile myotubes. These cells exhibit frequent spontaneous contractions, suggesting robust functional integrity at the neuromuscular junction. In parallel, we performed transcriptomic and metabolic profiling of native pectoralis tissue in the closely related Pteronotus parnellii to define molecular programs supporting muscle specialization. Gene expression analyses revealed enriched pathways for muscle metabolism, development, and regeneration, highlighting supporting roles in tissue maintenance and repair. Consistent with this profile, the flight muscle is triglyceride-rich, which serves as an important fuel source for energetically demanding processes, including muscle contraction and cellular recovery. Integration of transcriptomic and metabolic data identified three key metabolic modules—glucose utilization, lipid handling, and nutrient signaling—that likely coordinate ATP production and support metabolic flexibility. Together, these complementary tools and datasets provide the first in vitro platform for investigating bat muscle research, enabling direct exploration of muscle regeneration, metabolic resilience, and evolutionary physiology. Full article

Hydraulic actions may compromise dam foundation stability. Helical anchors have been used in dam foundation reinforcement projects because of the advantages of large uplift and compression bearing capacity, fast installation, and convenient recovery. However, the research on the anchor plate, which plays a key role in the bearing performance of helical anchors, is insufficient at present. Based on the finite element model of helical anchor, this study reveals the failure mode and influencing factors of the anchor plate and establishes the theoretical model of deformation calculation. The results showed that the helical anchor plate had obvious bending deformation when the dam foundation reinforced with a helical anchor reached large deformation. The helical anchor plate can be simplified to a flat circular disk. The stress distribution of the closed flat disk and the open flat disk was consistent with that of the helical disk. The maximum deformation of the closed flat disk was slightly smaller than that of the helical disk (less than 6%), and the deformation of the open flat disk was consistent with that of the helical disk. The results fill the blank of the design basis of helical anchor plate and provide a reference basis for the engineering design. Full article

Introduction: Despite clinical evidence for efficacy, there has been minimal uptake of transcranial direct current stimulation (tDCS) for musculoskeletal conditions. Thus, our objective was to explore the perceptions and experiences of people living with lower-limb musculoskeletal injury as well as healthy physically active populations and relate this to the usage of tDCS and key aspects of tDCS design that would improve the capacity for implementation. Methods: We conducted a qualitative descriptive study of 16 participants (44% women) using semi-structured focus groups to identify the descriptions and experiences of people living with lower-limb musculoskeletal injury and healthy physically active populations. A thematic template was used to create a coding structure. Codes were then grouped, and key themes were derived from the data. Results: Four primary themes were identified from focus groups. These were (i) the impact of musculoskeletal injuries on health and quality of life, (ii) performance and injury recovery as facilitators to using tDCS, (iii) barriers and facilitators to tCDS application and (iv) design and aesthetic factors for a tDCS device. Discussion: Our qualitative descriptive study identified four themes relevant to the successful implementation of tDCS into rehabilitative and performance practice. To increase the likelihood of successful tDCS implementation, these barriers should be addressed and facilitators promoted. This should include innovative approaches to device application and structure that allow for a stylish, user-friendly design. Full article

Remote sensing images are often degraded by atmospheric haze, which not only reduces image quality but also complicates information extraction, particularly in high-level visual analysis tasks such as object detection and scene classification. State-space models (SSMs) have recently emerged as a powerful paradigm for vision tasks, showing great promise due to their computational efficiency and robust capacity to model global dependencies. However, most existing learning-based dehazing methods lack physical interpretability, leading to weak generalization. Furthermore, they typically rely on spatial features while neglecting crucial frequency domain information, resulting in incomplete feature representation. To address these challenges, we propose ScaleViM-PDD, a novel network that enhances an SSM backbone with two key innovations: a Multi-scale EfficientViM with Physical Decoupling (ScaleViM-P) module and a Dual-Domain Fusion (DD Fusion) module. The ScaleViM-P module synergistically integrates a Physical Decoupling block within a Multi-scale EfficientViM architecture. This design enables the network to mitigate haze interference in a physically grounded manner at each representational scale while simultaneously capturing global contextual information to adaptively handle complex haze distributions. To further address detail loss, the DD Fusion module replaces conventional skip connections by incorporating a novel Frequency Domain Module (FDM) alongside channel and position attention. This allows for a more effective fusion of spatial and frequency features, significantly improving the recovery of fine-grained details, including color and texture information. Extensive experiments on nine publicly available remote sensing datasets demonstrate that ScaleViM-PDD consistently surpasses state-of-the-art baselines in both qualitative and quantitative evaluations, highlighting its strong generalization ability. Full article

The cement sheath is critical for ensuring the long-term safety and operational efficiency of oil and gas wells. However, complex geological conditions and operational stresses during production can induce cement sheath deterioration and cracking, leading to reduced zonal isolation, diminished hydrocarbon recovery, and elevated operational expenditures. This study investigates the development of a novel microbial self-healing well cement slurry system, employing fly ash as microbial carriers and sustained-release microcapsules encapsulating calcium sources and nutrients. Systematic evaluations were conducted, encompassing microbial viability, cement slurry rheology, fluid loss control, anti-channeling capability, and the mechanical strength, permeability, and microstructural characteristics of set cement stones. Results demonstrated that fly ash outperformed blast furnace slag and nano-silica as a carrier, exhibiting superior microbial loading capacity and viability. Optimal performance was observed with additions of 3% microorganisms and 3% microcapsules to the cement slurry. Microscopic analysis further revealed effective calcium carbonate precipitation within and around micro-pores, indicating a self-healing mechanism. These findings highlight the significant potential of the proposed system to enhance cement sheath integrity through localized self-healing, offering valuable insights for the development of advanced, durable well-cementing materials tailored for challenging downhole environments. Full article

Camellia oleifera, a woody oilseed species endemic to China, often experiences growth constraints due to seasonal drought. This study investigates the coordinated regulation of photosynthetic traits, stomatal behavior, and hormone responses during drought–rehydration cycles in two cultivars with contrasting drought resistance: ‘CL53’ (tolerant) and ‘CL40’ (sensitive). Photosynthetic inhibition resulted from both stomatal and non-stomatal limitations, with cultivar-specific differences. After 28 days of drought, the net photosynthetic rate (P_n) declined by 26.6% in CL53 and 32.6% in CL40. A stable intercellular CO₂ concentration (C_i) in CL53 indicated superior mesophyll integrity and antioxidant capacity. CL53 showed rapid P_n recovery and photosynthetic compensation post-rehydration, in contrast to CL40. Drought triggered extensive stomatal closure; >98% reopened upon rehydration, though the total stomatal pore area remained reduced. Abscisic acid (ABA) accumulation was greater in CL40, contributing to stomatal closure and P_n suppression. CL53 exhibited faster ABA degradation and gibberellin (GA₃) recovery, promoting photosynthetic restoration. ABA negatively correlated with P_n, transpiration rate (T_r), stomatal conductance (G_s), and C_i, but positively with stomatal limitation (L_s). Water use efficiency (WUE) displayed a parabolic response to ABA, differing by cultivar. This integrative analysis highlights a coordinated photosynthesis–stomata–hormone network underlying drought adaptation and informs selection strategies for drought-resilient cultivars and precision irrigation. Full article

Background/Objectives: This study aimed to compare the effects of low- and medium-frequency NMES, combined with a standard physical therapy (SPT) program, on functional capacity in critically ill patients. Methods: Fifty-four critically ill patients admitted into Intensive Care Unit (ICU) and on mechanical ventilation participated in this randomized, single-blinded, experimental study. Participants were randomly assigned to a Control group, who received a lower limb SPT program; the Low-frequency NMES group received lower limb SPT + NMES at 100 Hz; and the Medium-frequency NMES group received lower limb SPT + NMES at 100 Hz with a carrier frequency of 2500 Hz. The outcomes, encompassing functional capacity in the hospital, included muscle strength, handgrip strength, functional status, degree of independence for activities of daily living, functional and dynamic mobility, quality of life, and total days hospitalized. Results: Both NMES protocols combined with SPT improved functional capacity compared to the control group. Medium-frequency NMES provided additional benefits on dynamic balance, in the degree of independence to perform activities of daily living and quality of life (all p < 0.001) prior to hospital discharge. It also promoted larger gains on functional status prior to ICU discharge and on knee extension strength (both p < 0.05) prior to intermediate care unit discharge. Medium-frequency NMES also enhanced handgrip strength earlier than low-frequency NMES when compared to the control group. Notably, medium-frequency NMES was the only intervention associated with a significant reduction in total hospital stay duration (p < 0.05). Conclusions: Medium-frequency NMES, along with an SPT program in critically ill patients, showed greater benefits on functional capacity during recovery than low-frequency NMES. (Trial registration: This trial is registered on ClinicalTrials.gov: NCT05287919). Implications for rehabilitation: 1. Medium-frequency NMES may enhance physical functionality and quality of life in critically ill patients with ICU-acquired weakness. 2. Medium-frequency NMES can reduce the number of hospitalization days. 3. NMES combined with SPT represents a feasible and effective option for patients unable to engage in active rehabilitation during critical illness. Full article

This study aims to analyze the bending behavior of polylactic acid (PLA) structures made by fusion deposition modeling (FDM) technology. The investigation analyzed chiral structures such as lozenge and clepsydra, as well as geometries with wavy patterns such as roller and Es, in addition to a honeycomb structure. All geometries have a relative density of 50%. After being subjected to three-point bending tests, the capacity to spring back with respect to the bending angle and the shape recovery of the structures were measured. The roller and lozenge structures demonstrated the best performance, with shape recovery assessed through three consecutive hot water immersion cycles. The lozenge structure exhibits 25% higher energy absorption than the roller, but the latter ensures better replicability and shape stability. Additionally, the roller absorbs 15% less energy than the lozenge, which experiences a 27% decrease in absorption between the first and second cycle. This work provides new insights into the bending-based energy absorption and recovery behavior of PLA metamaterials, relevant for applications in adaptive and energy-dissipating systems. Full article

The diffusion coefficient (DC) of CO₂ in brine is a key parameter in geological carbon sequestration and CO₂-Enhanced Oil Recovery (EOR), as it governs mass transfer efficiency and storage capacity. This study employs three machine learning (ML) models—Random Forest (RF), Gradient Boost Regressor (GBR), and Extreme Gradient Boosting (XGBoost)—to predict DC based on pressure, temperature, and salinity. The dataset, comprising 176 data points, spans pressures from 0.10 to 30.00 MPa, temperatures from 286.15 to 398.00 K, salinities from 0.00 to 6.76 mol/L, and DC values from 0.13 to 4.50 × 10⁻⁹ m²/s. The data was split into 80% for training and 20% for testing to ensure reliable model evaluation. Model performance was assessed using R², RMSE, and MAE. The RF model demonstrated the best performance, with an R² of 0.95, an RMSE of 0.03, and an MAE of 0.11 on the test set, indicating high predictive accuracy and generalization capability. In comparison, GBR achieved an R² of 0.925, and XGBoost achieved an R² of 0.91 on the test set. Feature importance analysis consistently identified temperature as the most influential factor, followed by salinity and pressure. This study highlights the potential of ML models for predicting CO₂ diffusion in brine, providing a robust, data-driven framework for optimizing CO₂-EOR processes and carbon storage strategies. The findings underscore the critical role of temperature in diffusion behavior, offering valuable insights for future modeling and operational applications. Full article

As Chinese open-pit mines progressively transition to deeper operations, challenges such as rising stripping ratios, declining slope stability, and environmental degradation have become increasingly pronounced. The sustainability of traditional open-pit mining models faces substantial challenges. Underground mining, offering higher resource recovery rates and minimal environmental disruption, is emerging as a pivotal technological pathway for the green transformation of mining. Consequently, the transition from open-pit to underground mining has emerged as a central research focus within mining engineering. This paper provides a comprehensive review of key technological advancements in this transition, emphasizing core issues such as mine development system selection, mining method choices, slope stability control, and crown pillar design. A typical case study of the Anhui Xinqiao Iron Mine is presented to analyze its engineering approaches and practical experiences in joint development, backfilling mining, and ecological restoration. The findings indicate that the mine has achieved multi-objective optimization of resource utilization, environmental coordination, and operational capacity while ensuring safety and recovery efficiency. This offers a replicable and scalable technological demonstration for the green transformation of similar mines around the world. Full article

Construction and demolition byproducts include substantial amounts of wood panel waste (WPW) that pose environmental challenges. They also create opportunities for sustainable resource recovery. This study investigates the potential of WPW-derived biochar as an efficient adsorbent for phenol removal from aqueous solutions. Biochar was produced via pyrolysis at 450 °C and subsequent activation at 750, 850, and 950 °C. The biochar’s physicochemical properties, including surface area, pore volume, and elemental composition, were characterized using advanced methods, including BET analysis, elemental analysis, and adsorption isotherm analysis. Activated biochar demonstrated up to nine times higher adsorption capacity than raw biochar, with a maximum of 171.9 mg/g at 950 °C under optimal conditions: pH of 6 at 25 °C, initial phenol concentration of 200 mg/L, and biochar dosage of 1 g/L of solution for 48 h. Kinetic and isotherm studies revealed that phenol adsorption followed a pseudo-second-order model and fit the Langmuir isotherm, indicating chemisorption and monolayer adsorption mechanisms. Leaching tests confirmed the biochar’s environmental safety, with heavy metal concentrations well below regulatory limits. Based on these findings, WPW biochar offers a promising, eco-friendly solution for wastewater treatment in line with circular economy and green chemistry principles. Full article

Açaí (Euterpe oleracea) seeds account for up to 95% of the fruit’s weight and are commonly discarded during pulp processing. Roasted açaí seed extract (RASE) has recently emerged as a caffeine-free coffee substitute, although its composition and functionality remain underexplored. This study characterized commercial açaí seed powder and evaluated the effect of temperature on the recovery of total phenolic content (TPC) in the aqueous extract using a Central Composite Rotatable Design (CCRD). An intermediate extraction condition (6.0 ± 0.5 g 100 mL⁻¹ at 100 °C) was selected, resulting in 21.78 mg GAE/g TPC, 36.23 mg QE/g total flavonoids, and notable antioxidant capacity (FRAP: 183.33 µmol TE/g; DPPH: 23.06 mg TE/g; ABTS: 51.63 mg TE/g; ORAC: 31.46 µmol TE/g). Proton Nuclear Magnetic Resonance (¹H NMR) analysis suggested the presence of amino acids, carbohydrates, and organic acids. During in vitro digestion, TPC decreased from 54.31 to 17.48 mg GAE 100 mL⁻¹ when RASE was combined with goat milk. However, higher bioaccessibility was observed with skimmed (33%) and semi-skimmed (35%) cow milk. These findings highlight RASE as a phenolic-rich, antioxidant beverage with functional stability when prepared with boiling water. This is the first study to report the phytochemical profile of RASE and its interactions with different milk types, supporting its potential as a coffee alternative. Full article