Search Results (241)

Jujubes have a beautiful taste, and high nutritional and economic value. The planting area of dwarf and densely planted jujubes is large and shows an increasing trend; however, the mechanization level and efficiency of fresh jujube harvesting are low. For this reason, our research group conducted a study on mechanical harvesting technology for fresh jujubes. A pneumatic jujube harvester was designed. This harvester is composed of a self-regulating picking mechanism, a telescopic conveying pipe, a negative pressure generator, a cleaning mechanism, a double-chamber collection box, a single-door shell, a control assembly, a generator, a towing mobile chassis, etc. During the harvest, the fresh jujubes on the branches are picked under the combined effect of the flexible squeezing of the picking roller and the suction force of the negative pressure air flow. They then enter the cleaning mechanism through the telescopic conveying pipe. Under the combined effect of the upper and lower baffles of the cleaning mechanism and the negative-pressure air flow, the fresh jujubes are separated from impurities such as jujube leaves and branches. The clean fresh jujubes fall into the collection box. We considered the damage rate of fresh jujubes, impurity rate, leakage rate, and harvesting efficiency as the indexes, and the negative-pressure suction wind speed, picking roller rotational speed, and the inclination angle of the upper and lower baffles of the cleaning and selection machinery as the test factors, and carried out the harvesting test of fresh jujubes. The test results show that when the negative-pressure suction wind speed was 25 m/s, the picking roller rotational speed was 31 r/min, and the inclination angles of the upper and lower baffle plates for cleaning and selecting were −19° and 19.5°, respectively, the breakage rate of fresh jujube harvesting was 0.90%, the rate of impurity was 1.54%, the rate of leakage was 2.59%, and the efficiency of harvesting was 73.37 kg/h, realizing the high-efficiency and low-loss harvesting of fresh jujubes. This study provides a reference for the research and development of fresh jujube mechanical harvesting technology and equipment. Full article

Stable oxygen isotopes in tree rings (δ¹⁸O) serve as important proxies for climate change and offer unique advantages for climate reconstruction in arid and semi-arid regions. We established an annual δ¹⁸O chronology spanning 1964–2023 using Juniperus excelsa tree-ring samples collected from the Alborz Mountains in Iran. We analyzed relationships between δ¹⁸O and key climate variables: precipitation, temperature, Palmer Drought Severity Index (PDSI), vapor pressure (VP), and potential evapotranspiration (PET). Correlation analysis reveals that tree-ring δ¹⁸O is highly sensitive to hydroclimatic variations. Tree-ring cellulose δ¹⁸O shows significant negative correlations with annual total precipitation and spring PDSI, and significant positive correlations with spring temperature (particularly maximum temperature), April VP, and spring PET. The strongest correlation occurs with spring PET. These results indicate that δ¹⁸O responds strongly to the balance between springtime moisture supply (precipitation and soil moisture) and atmospheric evaporative demand (temperature, VP, and PET), reflecting an integrated signal of both regional moisture availability and energy input. The pronounced response of δ¹⁸O to spring evaporative conditions highlights its potential for capturing high-resolution changes in spring climatic conditions. Our δ¹⁸O series remained stable from the 1960s to the 1990s, but showed greater interannual variability after 2000, likely linked to regional warming and climate instability. A comparison with the δ¹⁸O variations from the eastern Alborz Mountains indicates that, despite some differences in magnitude, δ¹⁸O records from the western and eastern Alborz Mountains show broadly similar variability patterns. On a larger climatic scale, δ¹⁸O correlates significantly and positively with the Niño 3.4 index but shows no significant correlation with the Arctic Oscillation (AO) or the North Atlantic Oscillation (NAO). This suggests that ENSO-driven interannual variability in the tropical Pacific plays a key role in regulating regional hydroclimatic processes. This study confirms the strong potential of tree-ring oxygen isotopes from the Alborz Mountains for reconstructing hydroclimatic conditions and high-frequency climate variability. Full article

Stem radius growth (GRO), tree water deficit (TWD), and maximum daily shrinkage (MDS) were monitored throughout 2023 in a semi-arid Mediterranean forest stand in Burdur, Türkiye, where Pinus nigra subsp. pallasiana (Lamb.) Holmboe and Pinus brutia Ten. naturally co-occur. These indicators, derived from electronic band dendrometers, were analyzed in relation to key climatic variables. Results indicated that P. brutia had a longer growth period, while P. nigra exhibited a higher average daily increment under the environmental conditions of 2023 at the study site. Annual stem growth was nearly equal for both species. Based on dendrometer observations, P. brutia exhibited lower normalized TWD and higher normalized MDS values under varying vapor pressure deficit (VPD) and soil water potential (SWP) conditions. A linear mixed-effects model further confirmed that P. brutia consistently maintained lower TWD than P. nigra across a wide climatic range, suggesting a comparatively lower degree of drought-induced water stress. GRO was most influenced by air temperature and VPD, and negatively by SWP. TWD was strongly affected by both VPD and SWP, while MDS was primarily linked to minimum air temperature and VPD. Moreover, MDS in P. brutia appeared more sensitive to climate variability compared to P. nigra. Although drought limited stem growth in both species during the study year, the lower TWD and higher MDS observed in P. brutia may indicate distinct physiological strategies for coping with drought. These findings offer preliminary insights into interspecific differences in water regulation under the particular climatic conditions observed during the study year in this semi-arid Mediterranean ecosystem. Full article

Enhanced oil recovery (EOR) via CO₂ flooding is a promising strategy for improving hydrocarbon recovery and carbon sequestration, yet the influence of pH on solid–liquid interfacial interactions in quartz-dominated reservoirs remains poorly understood. This study employs molecular dynamics (MD) simulations to investigate the pH-dependent adsorption behavior of crude oil components on quartz surfaces and its impact on CO₂ displacement mechanisms. Three quartz surface models with varying ionization degrees (0%, 9%, 18%, corresponding to pH 2–4, 5–7, and 7–9) were constructed to simulate different pH environments. The MD results reveal that aromatic hydrocarbons exhibit significantly stronger adsorption on quartz surfaces at high pH, with their maximum adsorption peak increasing from 398 kg/m³ (pH 2–4) to 778 kg/m³ (pH 7–9), while their alkane adsorption peaks decrease from 764 kg/m³ to 460 kg/m³. This pH-dependent behavior is attributed to enhanced cation–π interactions that are facilitated by Na⁺ ion aggregation on negatively charged quartz surfaces at high pH, which form stable tetrahedral configurations with aromatic molecules and surface oxygen ions. During CO₂ displacement, an adsorption–stripping–displacement mechanism was observed: CO₂ first forms an adsorption layer on the quartz surface, then penetrates the oil phase to induce the detachment of crude oil components, which are subsequently displaced by pressure. Although high pH enhances the Na⁺-mediated weakening of oil-surface interactions, which leads to a 37% higher diffusion coefficient (8.5 × 10⁻⁵ cm²/s vs. 6.2 × 10⁻⁵ cm²/s at low pH), the tighter packing of aromatic molecules at high pH slows down the displacement rate. This study provides molecular-level insights into pH-regulated adsorption and CO₂ displacement processes, highlighting the critical role of the surface charge and cation–π interactions in optimizing CO₂-EOR strategies for quartz-rich reservoirs. Full article

Nicotine-induced oxidative stress contributes significantly to vascular endothelial dysfunction. While negative air ions (NAIs) demonstrate potential blood-pressure-regulating and antioxidant properties, their mechanistic role remains unclear. This study examined the effects of NAIs against nicotine-induced oxidative damage and vascular endothelial injury in spontaneously hypertensive rats (SHRs). Western blotting was used to detect the expression levels of the α7nAChR/MAPK/AP1 pathway. Transcriptomic sequencing was performed to identify the differentially expressed genes after treatment with nicotine or NAIs. Furthermore, reactive oxygen species (ROS), endothelin-1 (ET-1), and [Ca²⁺]_i levels were detected in human aortic endothelial cells (HAECs) treated with nicotine, and the relationship between transcription factor activator protein 1 (AP1) and the target genes was further elucidated through ChIP–qPCR. Nicotine exposure in SHRs elevated blood pressure and induced oxidative damage through α7nAChR/MAPK/AP1 pathway activation, causing endothelial structural disruption. These effects manifested as decreased NO/eNOS and increased ET-1/ET_ab expression, while these changes were reversed by NAIs. In HAECs, nicotine impaired proliferation while increasing oxidative stress and [Ca²⁺]_i levels. This endothelial damage was markedly attenuated by either NAIs or fibronectin 1 (Fn1)/secreted phosphoprotein 1 (Spp1) knockdown. Mechanistically, we identified AP1 as the transcriptional regulator of FN1 and SPP1. NAIs attenuate nicotine-induced endothelial dysfunction in hypertension by inhibiting AP1-mediated FN1 and SPP1 activation, providing novel insights for smoking-associated cardiovascular risk. Full article

Driven by climate change and stringent ecological conservation policies, arid and semi-arid pastoral areas face acute grassland degradation and forage–livestock imbalances. In Sunan County (Gansu Province, China), herders have increasingly turned to off-site grazing—leasing crop fields in adjacent oases during autumn and winter—to alleviate local grassland pressure and adapt their livelihoods. However, the interplay between the evolving land use system (L) and this emergent borrowed pasture system (B) remains under-explored. This study introduces a coupled analytical framework linking L and B. We employ multi-temporal remote sensing imagery (2018–2023) and official statistical data to derive land use dynamic degree (LUDD) metrics and 14 indicators for the borrowed pasture system. Through entropy weighting and a coupling coordination degree model (CCDM), we quantify subsystem performance, interaction intensity, and coordination over time. The results show that 2017 was a turning point in grassland–bare land dynamics: grassland trends shifted from positive to negative, whereas bare land trends turned from negative to positive; strong coupling but low early coordination (C > 0.95; D < 0.54) were present due to institutional lags, infrastructural gaps, and rising rental costs; resilient grassroots networks bolstered coordination during COVID-19 (D ≈ 0.78 in 2023); and institutional voids limited scalability, highlighting the need for integrated subsidy, insurance, and management frameworks. In addition, among those interviewed, 75% (15/20) observed significant grassland degradation before adopting off-site grazing, and 40% (8/20) perceived improvements afterward, indicating its potential role in ecological regulation under climate stress. By fusing remote sensing quantification with local stakeholder insights, this study advances social–ecological coupling theory and offers actionable guidance for optimizing cross-regional forage allocation and adaptive governance in arid pastoral zones. Full article

Acute heart failure (AHF) is a clinical syndrome characterized by the sudden onset or rapid worsening of heart failure signs and symptoms, frequently triggered by myocardial ischemia, pressure overload, or cardiotoxic injury. A central component of its pathophysiology is the activation of intracellular signal transduction cascades that translate extracellular stress into cellular responses. Among these, the mitogen-activated protein kinase (MAPK) pathways have received considerable attention due to their roles in mediating inflammation, apoptosis, hypertrophy, and adverse cardiac remodeling. The canonical MAPK cascades—including extracellular signal-regulated kinases (ERK1/2), p38 MAPK, and c-Jun N-terminal kinases (JNK)—are activated by upstream stimuli such as angiotensin II (Ang II), aldosterone, endothelin-1 (ET-1), and sustained catecholamine release. Additionally, emerging evidence highlights the role of receptor-mediated signaling, cellular stress, and myeloid cell-driven coagulation events in linking MAPK activation to fibrotic remodeling following myocardial infarction. The phosphatidylinositol 3-kinase (PI3K)/Akt signaling cascade plays a central role in regulating cardiomyocyte survival, hypertrophy, energy metabolism, and inflammation. Activation of the PI3K/Akt pathway has been shown to confer cardioprotective effects by enhancing anti-apoptotic and pro-survival signaling; however, aberrant or sustained activation may contribute to maladaptive remodeling and progressive cardiac dysfunction. In the context of AHF, understanding the dual role of this pathway is crucial, as it functions both as a marker of compensatory adaptation and as a potential therapeutic target. Recent reviews and preclinical studies have linked PI3K/Akt activation with reduced myocardial apoptosis and attenuation of pro-inflammatory cascades that exacerbate heart failure. Among the multiple signaling pathways involved, glycogen synthase kinase-3β (GSK-3β) has emerged as a key regulator of apoptosis, inflammation, metabolic homeostasis, and cardiac remodeling. Recent studies underscore its dual function as both a negative regulator of pathological hypertrophy and a modulator of cell survival, making it a compelling therapeutic candidate in acute cardiac settings. While earlier investigations focused primarily on chronic heart failure and long-term remodeling, growing evidence now supports a critical role for GSK-3β dysregulation in acute myocardial stress and injury. This comprehensive review discusses recent advances in our understanding of the MAPK signaling pathway, the PI3K/Akt cascade, and GSK-3β activity in AHF, with a particular emphasis on mechanistic insights, preclinical models, and emerging therapeutic targets. Full article

Understanding vegetation responses to atmospheric drought is critical for arid ecosystem management under climate change. However, the threshold of the response mechanism of grassland in arid regions to atmospheric drought remains unclear. This study investigates how vapor pressure deficit (VPD) regulates grassland gross primary productivity (GPP) in Xinjiang, China, using MODIS and other multi-source remote sensing data (2000–2020). The results show intensified atmospheric drought in central Tianshan Mountains and southern Junggar Basin, with VPD exhibiting a widespread increasing trend (significant increase: 15.75%, extremely significant increase: 4.68%). Intensified atmospheric drought occurred in the central Tianshan Mountains and southern Junggar Basin. Integrated analyses demonstrate that VPD has a dominant negative impact on GPP (path coefficient = −0.58, p < 0.05), primarily driven by atmospheric drought stress. A ridge regression-derived threshold was identified at 0.61 kPa, marking the point where VPD transitions from stimulating to suppressing productivity. Spatially, 58.75% of the total area showed a significant increase in GPP. These findings advance the mechanistic understanding of atmospheric drought impacts on arid ecosystems and inform adaptive grassland management strategies. Full article

The rapid expansion of plastic waste trade has intensified environmental pressures, accelerating ecosystem degradation and climate change. We examine the long-term impacts of plastic waste imports and domestic waste production on ecological footprints and greenhouse gas emissions across 20 countries representing 70% of global plastic waste trade and 45% of world GDP. Under the Environmental Kuznets Curve (EKC) framework, we explore nonlinear interactions among economic growth, urbanization, and sustainability goals. Using a panel simultaneous equations approach, we apply Pedroni, Kao, and Westerlund cointegration tests and Fully Modified and Dynamic OLS estimators to address endogeneity and heterogeneity. Robustness checks include alternative environmental indicators and the Dumitrescu–Hurlin panel causality test. Results demonstrate a stable long-run equilibrium: plastic waste imports substantially increase ecological footprints and emissions, while progress on sustainable development goals mitigates some damage. The negative GDP squared coefficient supports the EKC hypothesis, indicating that environmental impacts rise initially with growth but decline once income exceeds a threshold. These findings highlight the need for stronger international regulations, enhanced waste management infrastructures, and circular economy strategies. Focused investment in sustainable technologies and global cooperation is essential to lower environmental costs of plastic waste trade. Full article

There is limited understanding of what influences vaping cessation, especially as vaping regulations change, and different jurisdictions have different regulations. This study involves 281 ex-vapers (16–24 years) from Nova Scotia, Canada. A content analysis was used to understand and compare youth and young adults’ (YA) experiences of quitting vaping. Both helpful and unhelpful factors for quitting vaping were identified; each category had five themes and twenty-one sub-themes. Helpful factors were consistent across both age categories and included planned and unplanned vaping control interventions, health concerns, social support, evidence-based support, and unassisted quitting methods. Similarly, the five themes identified as unhelpful factors were consistent for both age groups: negative personal implications, negative social influences, planned and unplanned vaping control interventions, the side effects of previous use, and simultaneous and alternative substance use. Policies that limit access and raise awareness about lung health and well-being can help youth quit vaping. For YAs, increasing awareness about social support and health concerns is crucial. Raising e-cigarette costs and reducing vaping normalization supports quitting for YAs. Stress reduction and training to handle social pressure could aid youth, while YAs might benefit from treatment for other substance use to help with nicotine quitting. Full article

Green finance is widely promoted as a tool for supporting low-carbon development, but its effects on innovation efficiency remain unclear. This study examines the impact of China’s Green Finance Reform and Innovation Pilot Zones (GFRIPZ) on green innovation efficiency at the city level. Using the GFRIPZ policy as a quasi-natural experiment, we employ a difference-in-differences approach to identify the causal effects of the policy and explore the underlying mechanisms and contextual moderators. The results indicate that the policy significantly reduces green innovation efficiency in pilot cities, with the negative impact being more pronounced in non-central cities, provincial capitals, and cities in western China. Mechanism analysis reveals two key pathways: increased environmental costs contribute to resource lock-in, and strategic shifts toward quantity-focused innovation reduce overall efficiency. Furthermore, we find that the institutional environment plays a critical role—market integration mitigates the policy’s adverse effects by improving resource allocation, while administrative environmental pressure intensifies distortions. These findings suggest that rigid green finance regulations may unintentionally suppress innovation performance. We propose that more flexible policy design, better cross-regional coordination, and refined local governance incentives are essential for aligning green finance tools with innovation-driven sustainability goals in emerging economies. Full article

Background: Although B vitamins are implicated in cardiovascular regulation, the associations between serum thiamine (vitamin B1) and blood pressure (BP) remain unclear, particularly among women who are at high risk for hypertension-related complications. This study aimed to investigate relationships between serum thiamine levels and BP outcomes among middle-aged and elderly women in eastern China. Methods: A community-based cross-sectional study was conducted among 2015 women aged 45–69 years in Zhejiang Province, China. Serum thiamine levels were quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS). Hypertension was defined as measured BP ≥ 140/90 mmHg, or current use of antihypertensive medications. Multivariate logistic and linear regression models were used to assess associations of thiamine with hypertension prevalence and BP levels, respectively. Dose–response relationships were evaluated using restricted cubic splines (RCSs). Results: Higher thiamine levels were significantly associated with reduced hypertension prevalence (adjusted OR per SD increase: 0.87; 95%CI: 0.77, 0.97), with RCSs confirming linear dose–response (p-overall < 0.05, p-nonlinearity > 0.05). Compared with the lowest tertile, participants in the highest thiamine tertile had a 25% lower hypertension risk. Thiamine levels also showed negative associations with systolic BP (adjusted coef: −1.51 mmHg per SD; 95% CI: −2.33, −0.68), with the participants in the highest tertile showing a 3.94 mmHg reduction (95%CI: −5.97, −1.92). No significant relationship was found for diastolic BP. Conclusions: Serum thiamine is inversely associated with both hypertension prevalence and systolic BP in middle-aged and elderly women. This study supports the potential of serum thiamine as a modifiable biomarker in hypertension prevention strategies, particularly among aging women. Full article

Earth materials in construction demonstrate significant potential attributed to their accessibility, recyclability, and low energy demands for processing. Modern techniques have enhanced their mechanical strength and durability, enabling their application in load-bearing and infill walls while preserving ecological benefits. However, existing studies on indoor heat–humidity regulation primarily emphasize material parameters and macro-level performance. Moreover, the dynamic interactions between the unique thermal storage–release mechanisms and indoor environments have not been systematically analyzed. With the Kelvin equation, capillary mechanics, adsorption theories, and microstructural analysis were integrated in this study to quantify cyclic capillary condensation and evaporation in microvoids. The results reveal that earth materials contain abundant medium-sized pores (19.85–53.83 nm) sustaining vapor exchange with their surroundings. Capillary condensation occurs 0.86–0.96 times the planar surface vapor pressure, influenced by pore size (negatively correlated) and temperature (negatively correlated). During the daytime, capillary evaporation occurs in the nanopores of the raw earth wall under the influence of the outdoor environment’s cyclical temperature and humidity. This process absorbs heat from the indoor environment and raises the ambient humidity. During the nighttime, capillary condensation occurs in the pores, releasing heat to the indoor area and absorbing moisture from the environment, contributing to the balance of the indoor thermal environment of the earth buildings. The findings lay a scientific foundation for quantitatively evaluating earth buildings’ indoor climate control performance, supporting their integration into green building systems. This research bridges knowledge gaps in micro-to-macro thermal dynamics while advancing the ecological optimization of materials for sustainable architecture. Full article

Despite the formal protection of many natural areas, the problem of noise pollution poses a serious challenge to the preservation of their ecological integrity and biodiversity. Traffic noise generated by vehicle traffic on public roads disrupts natural biological processes, negatively affecting animals and the quality of the audiosphere. This research aimed to assess the acoustic impact of the public road network crossing the Roztocze National Park (RPN, Poland) and to characterize noise propagation as a factor polluting the environment and disrupting the functioning of natural forest ecosystems. The equivalent sound pressure level (L_Aeq) was measured at different distances from four public roads crossing the park. A terrain analysis was also taken into account to determine the impact of height differences on sound propagation. To enhance the acoustic analysis, recordings of environmental sounds were made, and their components, including both natural and anthropogenic sounds, were identified. It was found that traffic noise dominated natural sounds at distances 250 m from roads. The results obtained indicate the need for an integrated approach to protected area management, including noise monitoring, the implementation of noise protection regulations, and environmental education. Full article

Balancing ecological conservation with development pressures remains a critical challenge in regions hosting mega-events like the Winter Olympics. This study evaluates the ecological impacts of pre-Olympic construction in Chongli, China (2016–2021), through the integrated analysis of ecosystem service value (ESV) and landscape ecological risk (LERI). Using Sentinel-2 imagery and spatial statistics, we quantified land-use changes, applied benefit transfer methods for ESV assessment, and calculated the LERI using landscape pattern indices. The results revealed a 4.6% increase in the total ESV (266.4 to 278.7 million CNY), which was driven by afforestation initiatives that expanded the area of shrub-grassland and forests. Concurrently, the proportion of high/moderate LERI areas decreased by 12.3%, indicating reduced ecological vulnerability. Spatial correlation analysis demonstrated significant negative relationships between the ESV and LERI, particularly in zones that were undergoing ecological restoration. However, urban expansion weakened these synergies locally. The findings of this study highlight that strategic greening effectively enhanced ecosystem services while mitigating landscape risks during preparations for the Olympics. We propose an adaptive zoning framework that emphasizes dynamic ESV-LERI monitoring, tourism carrying capacity regulation, and payment for ecosystem service mechanisms to optimize post-event management. This integrated approach provides a transferable model for ecological governance in ecologically sensitive areas facing rapid development pressures, demonstrating the value of dual assessment methodologies in sustainable spatial planning. Full article