Search Results (101,286)

Supercritical carbon dioxide (SC-CO₂) fracturing has been recognized as an effective technology for developing unconventional oil and gas resources. The extent to which natural fractures can be activated is a critical factor controlling overall reservoir stimulation. A thorough understanding of the activation and propagation mechanisms of natural fractures during SC-CO₂ fracturing is therefore essential for elucidating fracture network evolution and optimizing stimulation strategies. In this work, a multiphysics-coupled numerical model for intersecting fracture propagation was developed using the phase-field method, incorporating formation pressure evolution and variations in CO₂ properties (density and viscosity). Based on this model, the influences of fracture approach angle, horizontal stress difference, injection temperature, and injection rate on fracture propagation patterns and pressure diffusion were systematically investigated. To quantitatively describe the stimulated reservoir volume, a “diffuse interface” was defined to represent the region affected by SC-CO₂ injection. The simulation results demonstrate that larger approach angles enhance the activation of natural fractures, with a 60° angle producing the maximum diffuse interface ratio of 72.5%. Although higher horizontal stress differences tend to suppress fracture activation, they promote plastic deformation at fracture tips, enlarging the diffuse interface to 86.72% at 15 MPa. Elevated injection temperatures further facilitate fracture propagation; as the temperature rises from 313.15 K to 403.15 K, the lateral fracture length increases from 2.8 cm to 3.7 cm, accompanied by continuous expansion of the diffuse interface. Under constant injection rate, a greater injection volume also enhances natural fracture activation and drives fractures to extend farther. These results provide theoretical insights for the design and optimization of SC-CO₂ fracturing in naturally fractured reservoirs. Full article

Driving with assistive devices creates complex cognitive and emotional demands that require systematic investigation. This study uses a multivariate approach based on subjective and objective measures to evaluate mental workload (MWL), stress and emotional state during simulated driving with an assistive device. Thirty healthy adults ($42\pm 13$ years of age, 7 females) completed four driving tasks combining two levels of difficulty (Easy vs. Hard) and two steering tools (wheel vs. single-pin aid). Subjective measures from NASA Task Load Index and Self-Assessment Manikin were collected, as well as physiological parameters from electroencephalographic, electrocardiographic, and electrodermal activity signals. The results revealed that the assistive device significantly induced increases in perceived physical demand, frustration, loss of emotional control and stress, yet reducing intrinsic sympathetic response represented by electrodermal activity parameters. Multivariate analyses highlighted that combining different physiological predictors improved MWL estimation. This study marks an initial step towards understanding the impact of assistive devices on MWL and stress in post-acute individuals returning to driving. Full article

Biochar and algal extracts are promising organic soil amendments, but their synergistic effects on soil organic matter and the sorption complex are still insufficiently understood. Therefore, a 30-day laboratory incubation experiment was conducted using a Haplic Luvisol to evaluate the effects of biochar (S+B), an N-rich algal extract (S+AGN), and their combined application (S+AGN+B) in comparison with the untreated control soil (S). The results showed that biochar led to a substantial increase in soil organic carbon (Corg) by 49% in S+B and by 50% in S+AGN+B treatments compared to S. Labile carbon (C_L) increased by 48% in S+B and by 40% in S+AGN+B. The algal extract alone did not significantly affect either C_L or Corg. Non-labile carbon increased by 2.22 g kg⁻¹ in S+B but slightly decreased in the combined treatment (−2.00 g kg⁻¹), indicating different dynamics of stable carbon fractions when both amendments are applied simultaneously. The combined treatment S+AGN+B, however, had the strongest effect on soil sorption properties. Specifically, the sum of basic cations was the highest among all treatments (189 mmol(+)kg⁻¹, i.e., +18–28 mmol(+)kg⁻¹ compared to S, S+B, and S+AGN), while the cation exchange capacity (CEC) reached the highest values (198 mmol(+)kg⁻¹, representing an increase of 7–27 mmol(+)kg⁻¹ compared to the other treatments). The base saturation remained high across all treatments, and the highest value was observed in S+AGN+B (95.6%). PCA confirmed that the combined treatment produced the most pronounced shifts in the multivariate parameter space and demonstrated a synergistic effect exceeding the effects of the individual organic amendments. Overall, the results indicate that biochar is the dominant factor contributing to the accumulation of stable carbon and the improvement of CEC, whereas the algal extract enhances the accumulation of labile carbon fractions and synergistically promotes the saturation of the sorption complex. The combined application of biochar and algal N effectively increases soil organic matter and sorption capacity. Full article

Agriculture plays a relevant role in the food supply chain but is also a major contributor in terms of emissions. A possible solution to reduce its impact is to replace traditional machinery with innovative systems, such as agricultural rovers. In the proposed research, a case study of an agricultural rover, specifically designed to operate in orchards, is presented. The powertrain features a Li-ion battery pack as the primary energy source and a fuel cell system operating as a range extender unit. Hydrogen is stored on board using a metal hydride tank to enhance compactness. Once the traction and range extender power output control strategies were defined, experimental tests in a closed warehouse were performed. During the tests, the rover was manually controlled using a joystick, since the main focus was to evaluate the powertrain behavior rather than to test the autonomous driving algorithm. During the tests, different maneuvers in narrow spaces were performed. The results showed that the rover successfully accomplished the tasks and the range extender unit can effectively extend the rover autonomy up to +150% compared to the pure battery solution. This result was obtained considering a 15 min test carried out in an indoor environment with a polished concrete floor. Full article

Studying soil microbiomes is challenging because soil contains thousands of microbial species at vastly different abundances. The choice of sequencing method has a strong effect on which of these species are detected and how the community is described. Three approaches now dominate soil microbiome research: short-read 16S rRNA amplicon sequencing on Illumina platforms, full-length 16S sequencing on Oxford Nanopore Technologies (ONT) platforms (particularly the R10.4.1 flow cell), and long-read shotgun metagenomics. Each has distinct biases that shape the recovered community, yet researchers routinely select a method based on cost, understanding, or local expertise rather than on a clear knowledge of what each approach methodically over- or under-represents. Here, we review head-to-head benchmarking studies that have applied two or more of these methods to the same soil or directly comparable samples. We show that while long-read and short-read 16S approaches generally converge on dominant taxa and on between-sample differences, they disagree substantially on alpha diversity estimates, rare taxon detection, and the relative abundances of entire phyla. The R10.4.1 flow cell chemistry has narrowed but not eliminated the accuracy gap with Illumina, and shotgun metagenomics reveals systematic biases in both short and long-read assembly that depend on population diversity within the sample. We synthesise this evidence into an evidence-based decision framework tied to specific research questions and recognise the gaps in soil-specific benchmarking that limit current methods. Rather than asking which platform is “best,” we argue that method choice should be framed as an important part of study design, with the biases of the chosen method acknowledged and, where possible, controlled for. Full article

The transient mechanism of dual-boundary dynamic opening in the inlet during stage transition of an integral solid rocket ramjet (ISRR) remains insufficiently understood. To address this issue, a combined approach involving numerical simulations and free-jet experiments was employed. A parametric model describing the time-sequenced opening of inlet and outlet cover was established. The influences of sequence and progression of opening and flight conditions on transient flow evolution and inlet stability were systematically examined. It is found that when the inlet is opened first, a “dead cavity” tends to form inside the inlet, which subsequently triggers pronounced pressure oscillations. Under baseline conditions, the peak outlet pressure reaches approximately 0.90 MPa, with a dominant frequency of about 66.7 Hz. Conversely, when the outlet is opened first, the cavity-induced oscillation is effectively suppressed; however, a transient “flow choking” overpressure and a delayed establishment of the flow field are observed. The discrepancies between simulations and experiments for key pressure characteristics under two representative opening modes are maintained within 5%, confirming the robustness of the proposed methodology. Further analysis reveals that increasing the Mach number markedly intensifies flow instability and reduces the stability margin, whereas higher flight altitudes help attenuate cavity oscillations. A strong coupling between the opening rate and temporal sequence is also identified. Specifically, for inlet-first scenarios, a slower inlet opening combined with a rapid outlet opening is preferable, while for outlet-first cases, rapid opening on both sides yields better performance. On this basis, a “stability window map” defined by the temporal difference (Δt) and opening duration (Topen) is proposed. This map delineates the distributions of stable, transitional, and hazardous regimes under varying conditions, which may offer a quantitative reference for adaptive control strategies in the ISRR stage of transition. Interestingly, these findings suggest that slight timing adjustments could substantially reshape the transient flow behavior. Notably, the introduction of the dual-boundary temporally coordinated forcing leads to flow responses within the inlet that exhibits pronounced path dependence and non-uniqueness. Such behavior deviates from the conventional understanding established under the single-boundary frameworks, where transient mode-transition processes were typically assumed to be uniquely determined. More importantly, these findings offer a renewed physical interpretation of inlet mode-transition dynamics, thereby providing both quantitative support and practical guidance for the adaptive design of ISRR transition control strategies. In particular, the results suggest that incorporating multi-boundary temporal effects could significantly enhance the robustness and flexibility of the control-law formulation. Full article

Employees’ voice is an important source of organizational learning and adaptive change. As algorithmic management is increasingly applied across organizational management processes, an urgent practical question arises: Does it affect employees’ participation in organizational improvement through voice? To address this challenge, drawing on signaling theory, this study examines the differential effects of distinct dimensions of algorithmic management on voice, while also considering work locus of control as a key moderating variable. We collected one-to-one matched data from 351 employees and their supervisors in a large Chinese platform-based enterprise. We tested the hypothesized theoretical model using structural equation modeling and bootstrapping procedures. The results show that algorithmic feedback enhances employees’ felt responsibility for constructive change, which in turn promotes employees’ voice. In contrast, algorithmic directing, algorithmic scheduling, and algorithmic monitoring undermine employees’ felt responsibility for constructive change and thereby inhibit voice. In addition, work locus of control moderates these relationships: employees with an external work locus of control strengthen the negative effects of algorithmic directing, algorithmic scheduling, and algorithmic monitoring, whereas employees with an internal work locus of control strengthen the positive effect of algorithmic feedback. These findings deepen our understanding of how different dimensions of algorithmic management shape voice and offer practical insights for fostering voice in contexts characterized by algorithmic management. Full article

Weaning disrupts intestinal structure and function in piglets and frequently results in post-weaning diarrhea, highlighting the need for effective nutritional alternatives to medicinal feed additives. This study evaluated non-fermented field peas and diets containing different inclusion levels of a fermented pea–wheat ingredient as substitutes for soybean meal in restricted liquid diets for weaned piglets. Fifty-six piglets were assigned to four dietary treatments for 14 days after weaning: non-fermented soybean meal, non-fermented peas, partial inclusion of the fermented pea–wheat ingredient, or full inclusion of the fermented pea–wheat ingredient. Fecal consistency, plasma inflammatory cytokines, small-intestinal morphology, crypt cell proliferation, and intestinal microbiota composition were assessed. Plasma interleukin-1β, interleukin-6, and tumor necrosis factor-α remained low and did not differ among treatments, indicating no measurable systemic inflammatory response. Diets containing the fermented pea–wheat ingredient were associated with differences in early intestinal morphology, particularly villus height on day 4 after weaning. Treatment- and segment-specific variation was also observed in crypt cell proliferation. Microbiota analysis showed differences in community composition among treatments, with diets containing the fermented pea–wheat ingredient associated with a higher relative abundance of lactic acid-producing genera. At the pen level, full inclusion of the fermented pea–wheat ingredient was consistently associated with low fecal scores, whereas partial inclusion was associated with higher fecal scores throughout the study period. Overall, these findings suggest that, under the controlled conditions of this study, diets containing the full inclusion level of the fermented pea–wheat ingredient were associated with indicators of intestinal adaptation and consistently low pen-level fecal scores. Further studies with replicated pen designs, longer-term performance evaluation, and functional analyses are needed before practical recommendations can be made. Full article

Glyphosate and its primary metabolite aminomethylphosphonic acid (AMPA) are widely detected in aquatic environments, yet their combined effects on fish remain insufficiently understood. This study used label-free blood plasma proteomic profiling to explore molecular patterns associated with 14-day exposure of juvenile common carp (Cyprinus carpio) to environmentally relevant concentrations of glyphosate (100 µg/L), AMPA (100 µg/L), and their mixture (50 + 50 µg/L). Across the three exposure groups, 41 proteins of interest showed pronounced abundance differences relative to the control based on fold-change selection criteria. These proteins were mainly associated with immune recognition, innate immune and complement-associated functions, coagulation and extracellular protease regulation, lipid/sterol transport, and extracellular matrix organization. In the mixture group, proteins of interest spanned several functional categories, suggesting that combined exposure deserves further attention in future studies of plasma-level responses to glyphosate and AMPA. Overall, these findings provide preliminary insights into blood plasma protein patterns associated with systemic responses of fish to glyphosate, AMPA, and their mixture at environmentally relevant concentrations and highlight the importance of considering parent compounds, metabolites, and their co-occurrence when assessing the potential biological effects of herbicide contamination in aquatic ecosystems. Full article

The Ili River Valley is a typical seasonally frozen region in which slope instability frequently occurs during the warm frozen-soil stage, generally at temperatures ranging from approximately −1.5 to 0 °C. In this context, changes in unfrozen water content play an important role in controlling the pore structure and mechanical behavior of warm frozen soil, yet the links among these factors remain insufficiently understood. This study investigates warm frozen soil from the Ili River Valley, with particular emphasis on the role of unfrozen water content in regulating pore-structure characteristics and mechanical response under low-temperature conditions. Low-field nuclear magnetic resonance (NMR), low-temperature triaxial shear tests, scanning electron microscopy (SEM), and quantitative image analysis were employed to examine the relationships between unfrozen water content, pore structure, and macroscopic mechanical properties under different temperatures, initial water contents, and confining pressures. The results show that unfrozen water content decreases markedly with decreasing temperature, especially within the range of −1.5 to −5 °C, and increases with increasing initial water content. These changes are accompanied by significant variations in porosity, pore abundance, and pore fractal dimension, reflecting freezing-induced reorganization of the pore system. Lower temperatures and higher initial water contents promote ice-crystal growth and the formation of larger ice-cemented aggregates, thereby modifying the pore framework. Meanwhile, peak strength and cohesion increase with decreasing temperature and increasing initial water content, whereas the internal friction angle shows a decreasing trend. In addition, porosity, pore abundance, and pore fractal dimension are closely correlated with peak strength and cohesion. The results indicate that unfrozen water content governs the freezing-induced reorganization of pore structure, which in turn controls the strength evolution of warm frozen soil. These findings improve understanding of the role of unfrozen water in low-temperature soil structure and strength evolution and provide a basis for evaluating slope instability in the Ili River Valley. Full article

The aging population and the high incidence of neurological disorders have driven an increasing demand for lower-limb motor dysfunction rehabilitation. Traditional rehabilitation methods suffer from limitations such as low efficiency and a lack of personalization. Lower-limb rehabilitation exoskeleton robots have emerged as a critical solution, with human–robot intelligent fusion serving as the core theoretical framework and technological pathway for performance enhancement. From the unique perspective of human–robot intelligent fusion, this paper systematically reviews the application and recent advances of artificial intelligence in three key aspects—intention perception, intelligent control, and human–robot integration—based on a layered architecture of “fusion perception, fusion decision-making, and fusion execution”. The definition, connotations, and realization mechanisms of human–robot intelligent fusion are clarified. Furthermore, this review analyzes the fusion mechanisms, applicable scenarios, and technical characteristics of different AI technologies and summarizes the human–robot intelligent fusion modes and clinical application status of representative products such as EksoNR, MyoSuit, and AiLegs. In addition, key challenges are identified from the perspectives of fusion generalization capabilities, the trade-off between real-time performance and robustness, algorithm interpretability, and multimodal deep fusion mechanisms. This paper provides a systematic theoretical reference and technical roadmap for establishing a unified human–robot intelligent fusion framework for lower-limb rehabilitation exoskeletons. Full article

Introduction: This study evaluated the implications of intravenous acetaminophen (Ofirmev) on perioperative outcomes in patients undergoing robotic-assisted laparoscopic prostatectomy (RALP) for prostate cancer. The primary objective was to determine whether adding IV acetaminophen to standard analgesia could reduce hospital length of stay (LOS), pain intensity, and opioid use compared with placebo. Methods: This study was conducted as a secondary descriptive analysis of publicly available aggregate results from a previously completed randomized, double-blind, placebo-controlled Phase IV trial (NCT02369211). No individual patient-level data were accessed, and no new independent statistical analyses were performed. Eighty-six male patients were randomly assigned to receive either 1 g IV acetaminophen or saline placebo every six hours for four doses during the perioperative period. Primary endpoints were hospital and post-anesthesia care unit (PACU) LOS; secondary endpoints included postoperative pain scores and opioid consumption (morphine milligram equivalents). Results: Baseline characteristics were similar between groups (n = 43 each). Mean PACU stay was slightly shorter with IV acetaminophen (124 ± 58 min) than placebo (132 ± 63 min; not significant). Median hospital LOS was 0.81 days versus 0.82 days (p = 0.006), a statistically significant difference reported in the original trial dataset, although the absolute difference was clinically minimal. Pain scores and opioid requirements were lower with IV acetaminophen but not significantly different. No adverse events occurred in either group. Conclusions: IV acetaminophen was safe and well tolerated as part of multimodal analgesia for RALP. Although pain scores and opioid use numerically favored IV acetaminophen, these differences were not statistically significant. The reported difference in hospital LOS was statistically significant in the original trial record but clinically minimal; therefore, the findings should be interpreted as exploratory and hypothesis-generating regarding potential operational and economic implications. Full article

Controlled-release fertilizer (CRF) improves fertilizer-use efficiency through sustained nutrient release, but its rate-dependent effects on the growth and physiology of Paeonia delavayi seedlings remain unclear. In this study, germinated seeds of P. delavayi with radicles 3–4 cm in length were grown under container nursery conditions with four CRF application rates: (CK, 0 kg·m⁻³), treatment 1 (T1, 0.6 kg·m⁻³), treatment 2 (T2, 1.2 kg·m⁻³), and treatment 3 (T3, 2.4 kg·m⁻³). Morphological traits, root characteristics, biomass accumulation, physiological parameters, and chlorophyll fluorescence were evaluated, and Pearson correlation and fuzzy membership analyses were used to compare overall treatment performance within the tested range. CRF significantly promoted seedling height, leaf number, petiole length, and biomass accumulation, although the promoting effect did not increase continuously with fertilizer rate. By June, seedling height in T2 was 160% greater than that in CK, while aboveground biomass increased by 552% and 574% in T2 and T3, respectively. Root morphological traits were not significantly affected, suggesting that CRF primarily promoted aboveground development and biomass production. Medium and high CRF rates increased leaf superoxide dismutase (SOD) activity by 42% and 103%, respectively, and peroxidase (POD) activity by 163% and 250%, respectively. Aboveground starch content was 45% higher in T2 than in CK. In contrast, photosynthetic pigment contents and the chlorophyll a/b ratio were not significantly affected by CRF. Chlorophyll fluorescence analysis showed that Fv/Fm remained stable among CRF treatments (0.78–0.82) and was significantly higher than that in CK (0.65), whereas the actual quantum yield of PSII [Y(II)] did not differ significantly among treatments. Relative to CK, tthe quantum yield of non-photochemical quenching [Y(NPQ)] increased from 0.20 to 0.40 in T2, while the quantum yield of non-regulated energy dissipation in PSII [Y(NO)] decreased from 0.37 to 0.24–0.22 in T2–T3. Pearson correlation and fuzzy membership analyses ranked the treatments as T2 > T3 > T1 > CK, indicating that T2 performed most favorably within the tested range, although its advantage over T3 was small. Overall, an appropriate CRF rate promoted P. delavayi seedling growth and was associated with changes in biomass accumulation, antioxidant enzyme activity, carbon assimilate storage, and chlorophyll fluorescence parameters. Full article

Background/Objectives: SARS-CoV-2 infection may exacerbate neuroinflammation in patients with multiple sclerosis (MS) and thus accelerate MS progression. Previous studies have reported an increased risk of disability and lesion burden among those infected with SARS-CoV-2 while others reported no differences compared to COVID− controls. We aimed to determine whether COVID-19 is associated with accelerated radiological progression of MS. Methods: This single-center, retrospective longitudinal study included patients with pre-existing relapsing-remitting MS. We identified 34 SARS-CoV-2–positive MS patients (COVID+) who had at least one brain MRI prior to, and one after, their first positive PCR test. These patients were matched 2:1 by index date to 67 SARS-CoV-2–negative MS patients (COVID−). Baseline demographics and comorbidities were comparable between groups. Two radiologists independently scored pre- and post-index MRIs for new or enlarging T2 lesions, T1 gadolinium-enhancing lesions, and parenchymal brain volume loss. Logistic regression analyses evaluated group differences, adjusting for demographic and clinical covariates. Results: Across an average imaging interval of approximately two years, no significant differences were observed between COVID+ and COVID− patients in new lesions (8.8% vs. 9.0%), enlarging lesions (2.9% vs. 6.0%), T1-enhancing lesions (5.9% vs. 1.5%), or brain volume loss (35.3% vs. 47.8%; all p > 0.05). Conclusions: There was no detectable association between SARS-CoV-2 infection and accelerated radiological progression in patients with MS over an average two-year follow-up. Longer-term investigations are warranted to clarify whether certain subgroups or more severe COVID-19 cases might be at heightened risk. Full article

Sweetpotato (Ipomoea batatas (L.) Lam.) is an important multifunctional crop with great value in food supply, industrial processing and bioenergy utilization. Crude protein content (CPC) is a core target trait for sweetpotato quality breeding. To dissect the genetic basis of CPC and identify key candidate genes, we used an F₁ population of 212 individuals. CPC was measured by near-infrared reflectance spectroscopy (NIRS) in 2020 and 2021, and QTL mapping was performed using a high-density SNP genetic linkage map. Candidate genes were explored via a genome-wide association study (GWAS), multiple-database functional annotation, and quantitative real-time PCR (qPCR) validation. The results showed that: (1) CPC in the population exhibited a continuous normal distribution with high inter-year stability, and phenotypic variation was mainly controlled by genetic factors; (2) one stable minor-effect QTL for CPC, qCPC09-1, was mapped to Chr09: 7906895–8614924 bp, explaining 5.7% of phenotypic variation; (3) GWAS detected no significant SNP loci, suggesting that CPC is regulated by multiple minor-effect genes; (4) genes within the qCPC09-1 interval were significantly enriched in three protein synthesis-related KEGG pathways: ribosome, nitrogen metabolism and ubiquinone and other terpenoid–quinone biosynthesis; (5) qPCR verified that itf09g13420 and itf09g13230 were upregulated in the low-CPC parent Yushu 10 and negatively correlated with CPC, while itf09g13550 was upregulated in the high-CPC parent Xin 24 and positively correlated with CPC. These three genes exhibited expression patterns highly consistent with phenotypic differences. This study provides a theoretical basis and technical support for molecular marker-assisted breeding and elite germplasm innovation in sweetpotato. Full article