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1.
Article in English | MEDLINE | ID: mdl-39278733

ABSTRACT

Coronary circulation plays an essential role in delivering oxygen and metabolic substrates to satisfy the considerable energy demand of the heart. This article reviews the history that led to the current understanding of coronary physiology, beginning with William Harvey's revolutionary discovery of systemic blood circulation in the 17th century, and extending through the 20th century when the major mechanisms regulating coronary blood flow (CBF) were elucidated: extravascular compressive forces, metabolic control, pressure-flow autoregulation, and neural pathways. Pivotal research studies providing evidence for each of these mechanisms are described, along with their clinical correlates. The authors describe the major role played by researchers in the 19th century, who formulated basic principles of hemodynamics, such as Poiseuille's law, which provided the conceptual foundation for experimental studies of CBF regulation. Targeted research studies in coronary physiology began in earnest around the turn of the 20th century. Despite reliance on crude experimental techniques, the pioneers in coronary physiology made groundbreaking discoveries upon which our current knowledge is predicated. Further advances in coronary physiology were facilitated by technological developments, including methods to measure phasic CBF and its regional distribution, and by biochemical discoveries, including endothelial vasoactive molecules and adrenergic receptor subtypes. The authors recognize the invaluable contribution made by basic scientists toward the understanding of CBF regulation, and the enormous impact that this fundamental information has had on improving clinical diagnosis, decision-making, and patient care.

2.
Sci Rep ; 14(1): 20311, 2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39218943

ABSTRACT

Human activities have profound impacts on land use and the supply-demand balance of ecosystem services (ESs). Various activities, such as urban construction, urban and rural planning, and inter-basin water transfer projects, continuously reshape land use patterns. This is a case study of the Anhui section of the Yangtze-Huaihe Water Diversion Project. Data from 2000, 2010, and 2020 is analyzed. Additionally, the patch-generating land use simulation (PLUS) model is utilized to quantify the specific impacts of the water diversion project construction on the supply and demand of ESs. The results indicate that the comprehensive dynamic attitude of land use during the project construction period significantly increased, rising from 0.16 to 13.79%, and mainly affected forest, water areas, construction land, and unused land. Specifically, the construction of the project led to significant changes in water purification, biodiversity, and, especially, hydrological regulation services. Additionally, the migration of residents significantly impacted the demand for ESs. The study also found a significant correlation between land use changes and the balance of ES supply and demand: the proportion of cultivated land and construction land is positively correlated with the balance, while the proportion of forest, grassland, and water areas is negatively correlated. This study provides empirical data for understanding the environmental and socio-economic impacts of large-scale water diversion projects and offers a scientific basis for local mitigation and control of adverse impacts. Through quantitative analysis and model prediction, this research effectively bridges the gap between theory and practice, providing important references for sustainable regional development.

3.
J Environ Manage ; 370: 122532, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39303587

ABSTRACT

Matching the supply and demand of related ecosystem services can be an effective way to realize long-term sustainable management of the food-energy-water nexus (FEW Nexus) in drylands. However, few studies have focused on the matching of supply and demand for ecosystem services associated with advancing the sustainability of FEW-Nexus, there is limited research in this domain, which lacks systematic and quantitative analysis of the relationship between them and FEW Nexus sustainability. Here, this research takes the West Liaohe River Basin in the arid region of China as a case study. Based on a localized FEW Nexus sustainability evaluation index system, the FEW Nexus sustainability and the supply-demand matching characteristics of the corresponding ecosystem services in the West Liaohe River Basin from 2005 to 2015 were assessed. The relationship between them was analyzed quantitatively through the methods of coupling coordination degree and geographical detector. The results showed a synergistic improvement in both FEW Nexus sustainability and the supply-demand situation of combined ecosystem services. The supply of food production and water yield were able to meet their demands adequately from 2005 to 2015, with a strengthening surplus, leading to an overall surplus and gradual improvement in the integrated ecosystem services. This surplus synergistically promoted the process of FEW Nexus sustainability. The results of the geographical detector indicate that the supply-demand ratio of carbon sequestration was the main factor influencing FEW Nexus sustainability. Areas with higher FEW Nexus sustainability tended to have larger deficits in carbon sequestration, which was more evident in areas with high levels of urbanization. Therefore, the key to enhancing FEW Nexus sustainability in the basin is to balance the supply of and demand for carbon sequestration services. Overall, the present study not only provides a basis for strengthening the management of the supply-demand of ecosystem services associated with FEW to achieve regional sustainable development, but also offers insights into how the growing demand for the FEW Nexus is exerting pressure on the balance between supply and demand of related ecosystem services.

4.
Environ Sci Technol ; 2024 Aug 13.
Article in English | MEDLINE | ID: mdl-39137304

ABSTRACT

As the largest iron and steel producer, China still cannot meet its demand of iron and steel only through domestic primary supply in the last few decades. Hence, secondary iron resources are increasingly significant in meeting China's iron supply and demand balance. However, the secondary iron resource availability in China and how it impacts the future supply demand balance were still insufficiently discussed. In this work, we developed a material flow analysis and secondary resources reserve assessment (MFA-SRRA) integrated model, assessed secondary iron resources availability, and conducted a supply demand analysis through nine scenarios for irons in China. The results showed that China's secondary iron reserves will increase from 8.9 Gt in 2021 to 14.04 to 19.01 Gt in 2050. With the increasing secondary iron supply, more than 60% of iron ore as a source of steelmaking can be replaced by 2050. Landfills, as a significant reserve of iron but always ignored, will accumulate 1.42-1.51 Gt secondary iron resources by 2050 and should be noticed to be mined and utilized in the future. Last, we suggest that promoting innovation in landfill mining technology and making sustainable material management policies are urgent to prevent these secondary iron resources from becoming real waste.

5.
J Environ Manage ; 365: 121698, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38968890

ABSTRACT

In China, over 65% of human activities are concentrated in cities, resulting in a conflict between the supply and demand of ecosystem services (ESs). To alleviate this problem, many cities have adopted eco-friendly development modes, however, the effectiveness of these models in reducing ESs supply-demand conflicts has not been comprehensively reviewed, and the human and natural drivers behind these relationship shifts remain unclear. To bridge this gap, this study analyzed the shifts in the relationships between supply and demand of ESs across China from 2010 to 2020 at a city level, as well as identified the human and natural drivers behind them. Firstly, the InVEST models were integrated with socioeconomic data to evaluate the supply and demand distribution for three pivotal ESs: water yield (WY), habitat quality (HQ), and soil retention (SR). Then, a four-quadrant diagram approach was proposed to enhance the analysis of their spatiotemporal relationships. Furthermore, random forest models were employed to examine the drivers of the shifts in these relationships. The results showed that WY and SR services witnessed growth until 2015, and then receded, while HQ saw a modest decline from 2010 to 2020. Spatial synergies in the supply and demand of ESs were primarily observed in the southern cities, with a significant northward extension by 2020. From a temporal perspective, the percentage of cities achieving coordination in WY and SR services increased from 32.6% to 57.3%, respectively, in the 2010-2015 period to 42.4% and 63.3% between 2015 and 2020, meanwhile, HQ service conflicts diminished from 58.7% to 53.5%. The changes in socioeconomic and land use factors contributed to 64.3%, 36.1%, and 33.3% of the shifts in the supply-demand relationship for HQ, WY, and SR services, respectively. Our analysis highlights the potential of human-driven ecological management to enhance the balance of this relationship. It can support the design of city-specific policies that foster a balance between ecological processes and socio-economic development.


Subject(s)
Conservation of Natural Resources , Ecosystem , China , Humans , Cities , Soil
6.
Sci Rep ; 14(1): 13348, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38858436

ABSTRACT

This study aims to design a classification technique suitable for Zhuang ethnic clothing images by integrating the concept of supply-demand matching and convolutional neural networks. Firstly, addressing the complex structure and unique visual style of Zhuang ethnic clothing, this study proposes an image resolution model based on supply-demand matching and convolutional networks. By integrating visual style and label constraints, this model accurately extracts local features. Secondly, the model's effectiveness and resolution performance are analyzed through various performance metrics in experiments. The results indicate a significant improvement in detection accuracy at different annotation points. The model outperforms other comparative methods in pixel accuracy (90.5%), average precision (83.7%), average recall (80.1%), and average F1 score (81.2%). Next, this study introduces a clothing image classification algorithm based on key points and channel attention. Through key point detection and channel attention mechanisms, image features are optimized, enabling accurate classification and attribute prediction of Zhuang ethnic clothing. Experimental results demonstrate a notable enhancement in category classification and attribute prediction, with classification accuracy and recall exceeding 90% in top-k tasks, showcasing outstanding performance. In conclusion, this study provides innovative approaches and effective solutions for deep learning classification of Zhuang ethnic clothing images.

7.
Heliyon ; 10(11): e32006, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38867976

ABSTRACT

Establishing ecological management zones based on the supply-demand relationship of ecosystem services (ESs) is essential for fostering sustainable development within social-ecological systems and improving human well-being. In this study, the spatial pattern between supply and demand in five ESs (grain production (GP), carbon sequestration (CS), soil conservation (SC), water conservation (WC), and habitat quality (HQ)) is analyzed using the ESs supply-demand ratio (ESDR) method, the spatial autocorrelation method, and the coupled coordination degree model. Zoning is performed according to the differences in their spatial combinations, and differential zoning management policies are proposed. The following results were obtained: (1) In terms of the ESDR, except for a slight increase in GP surplus from 2010 to 2020, there is a decline in the surplus of the other four ESs. (2) CS, WC, and HQ are dominated by cluster types LH and HL. GP and SC are dominated by cluster types HH and LL. The average value of the coupling coordination degree (CCD) of comprehensive ESs supply and demand show five types: moderate disharmony, slight disharmony, near disharmony, basic coordination, and slight coordination. (3) Based on the multiple spatial heterogeneity of ESs supply and demand, differentiated ecological management strategies are proposed at the grid scale. Overall, this study discover the spatial pattern of mismatch between the supply and demand of ecosystem services (ESs) in mountainous urban areas. This contribution enhances the discourse surrounding sustainable development theory and advances research on the coupling of social-ecological systems. Furthermore, it offers valuable insights for the formulation of sustainable ecological management policies tailored to mountainous urban settings.

8.
Ying Yong Sheng Tai Xue Bao ; 35(5): 1347-1358, 2024 May.
Article in Chinese | MEDLINE | ID: mdl-38886434

ABSTRACT

In the context of rapid urbanization, metropolitan areas are facing the risk of supply-demand mismatches among ecosystem services. Investigating the patterns, relationships, and driving factors of multiple supply-demand risks is of great significance to support the efficient management of regional ecological risks. We quantified the single/comprehensive supply-demand risk rates of six ecosystem services in Wuhan Metropolitan Area at the township scale in 2000, 2010, and 2020. By applying the self-organizing feature map network and optimal parameter geo-detector, we identified supply-demand risks bundles of ecosystem services and influencing factors of comprehensive risks. The results showed significant spatial variations in the supply-demand risks of typical ecosystem services from 2000 to 2020. The supply-demand risk associated with grain production, water yield, carbon sequestration, and green space recreation increased, while soil conservation and water purification risks decreased. The comprehensive ecosystem services supply-demand risk increased from 0.41 to 0.45, indicating a 'core area increase and periphery decrease' trend. Throughout the study period, the area exhibited bundles of comprehensive extremely high-risk bundles (B1), comprehensive high-risk bundles (B2), water purification high-risk bundles (B3), and grain production-soil conservation risk bundles (B4). The transition of risk types from B3 to B2 and from B2 to B1 suggested an increase in the combination and intensity of supply-demand risk. Vegetation cover, nighttime light index, and population density were the main driving factors for spatial variations in comprehensive supply-demand risk. Ecologi-cal risk assessment based on ecosystem services supply-demand bundles could provide an effective and reliable way to regulate multiple regional risk issues.


Subject(s)
Cities , Conservation of Natural Resources , Ecosystem , China , Risk Assessment , Ecology , Environmental Monitoring , Urbanization
9.
J Environ Manage ; 365: 121510, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38909580

ABSTRACT

Exposure to green environments is crucial for human health. However, urbanization has reduced the contact of urban residents with natural environments, causing a mismatch between the supply and demand for green exposure. Research in this field is hindered by the lack of long-term, reliable data sources and methodologies, leading to insufficient consideration of temporal variations in green exposure. This study presented a comprehensive methodology for assessing green exposure at a fine scale utilizing satellite images for urban tree canopy identification. We conducted a case study in the core area of Beijing from 2010 to 2020 and examined the effects of urban renewal and alleviation efforts. The results revealed a slight decrease in green exposure for the elderly over the decade, with minimal changes in equity. In contrast, green exposure for children has increased, with increasing inequality. Moreover, urban renewal has improved green exposure for nearly half of the low-supply blocks. However, a significant mismatch was observed between supply and demand for blocks with increased demand but limited supply. This study enhances the assessment of green exposure and provides guidance for planning and constructing a "Green Equal City".


Subject(s)
Cities , Urbanization , Humans , Beijing
10.
J Anesth ; 38(5): 622-630, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38842681

ABSTRACT

PURPOSE: This study was performed to evaluate the changes in oxygen supply-demand balance during induction of general anesthesia using an indirect calorimeter capable of measuring oxygen consumption (VO2) and carbon dioxide production (VCO2). METHODS: This study included patients scheduled for surgery in whom remimazolam was administered as a general anesthetic. VO2 and VCO2 were measured at different intervals: upon awakening (T1), 15 min after tracheal intubation (T2), and 1 h after T2 (T3). Oxygen delivery (DO2) was calculated simultaneously with these measurements. VO2 was ascertained using an indirect calorimeter and further calculated using vital signs, among other factors. DO2 was derived from cardiac output and arterial blood gas analysis performed with an arterial pressure-based cardiac output measurement system. RESULTS: VO2, VCO2, and DO2 decreased significantly from T1 to T2 and T3 [VO2/body surface area (BSA) (ml/min/m2): T1, 130 (122-146); T2, 107 (83-139); T3, 97 (93-121); p = 0.011], [VCO2/BSA (ml/min/m2): T1, 115 (105-129); T2, 90 (71-107); T3, 81 (69-101); p = 0.011], [DO2/BSA (ml/min/m2): T1, 467 (395-582); T2, 347 (286-392); T3, 382 (238-414); p = 0.0020]. Among the study subjects, a subset exhibited minimal reduction in VCO2. Although the respiratory frequency was titrated on the basis of end-tidal CO2 levels, there was no significant difference between the groups. CONCLUSION: General anesthetic induction with remimazolam decreased VO2, VCO2, and DO2.


Subject(s)
Anesthesia, General , Benzodiazepines , Carbon Dioxide , Oxygen Consumption , Oxygen , Humans , Anesthesia, General/methods , Female , Male , Middle Aged , Oxygen Consumption/drug effects , Oxygen Consumption/physiology , Oxygen/metabolism , Oxygen/blood , Carbon Dioxide/metabolism , Benzodiazepines/administration & dosage , Blood Gas Analysis/methods , Adult , Aged , Cardiac Output/drug effects , Cardiac Output/physiology , Hypnotics and Sedatives/administration & dosage , Hypnotics and Sedatives/pharmacology
11.
Environ Sci Pollut Res Int ; 31(19): 27710-27729, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38514593

ABSTRACT

Accurate assessment of ecosystem service (ES) supply, demand, and flow is essential for identifying and enhancing the ES supply-demand relationship and promoting regional sustainable development. Based on the InVEST model, supply-demand ratio, coupling coordination analysis, breakpoint and field strength model, and GIS spatial analysis method, we evaluated the supply and demand of water yield, food supply, carbon storage, and soil conservation service in the Loess Plateau in 2000 and 2020 and analyzed the supply-demand relationship before and after considering the interregional ecosystem service flow (ESF). The results showed that (1) from 2000 to 2020, the supply and demand of the four types of ESs in the Loess Plateau increased. Before considering ESF, the surplus degree in water yield, food supply, and soil conservation increased, and carbon storage decreased. In most counties, the coupling coordination between the supply and demand of the soil conservation is mostly extreme incoordination and moderate incoordination, and other types of ESs are mostly reluctant coordination and moderate incoordination. The degree of incoordination in water yield and soil conservation have eased, while food supply and carbon storage have strengthened. For the comprehensive supply-demand relationship of ES, the degree of surplus and coordination increased, with most counties were in a state of surplus and coordination. (2) Water yield and soil conservation services flow primarily to the western and northwestern portions of the Loess Plateau, with a decrease in the number of flow paths but an increase in the total flow rate for the former and a decrease in flow paths and total flow rate for the latter. The food supply and carbon storage flow in all directions and the total flow rate increases, with a significant increase in the number of flow paths for carbon storage. (3) After considering ESF, the supply-demand relationship of each type of ES and the comprehensive ES supply-demand relationship are changed, in which the degree of surplus and coordination of deficit counties are significantly improved, and some counties even become surplus or improve the level of coordination. After considering ESF, the supply-demand ratio changes even more relative to the degree of coupling coordination. This study is of great significance for identifying the cross-regional transfer pattern of ES, understanding in-depth the dynamic supply-demand relationship of ES, and mitigating the mismatch between supply and demand of ES. It provides a scientific and objective theoretical basis for promoting regional sustainable development.


Subject(s)
Conservation of Natural Resources , Ecosystem , Soil
12.
Heliyon ; 10(5): e26766, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38468959

ABSTRACT

Currently, China's building materials market is large and the supply and demand transactions are very frequent, which requires us to have a comprehensive understanding of the supply and demand transactions of building materials. Based on complex network theory, this paper constructs a complex network model of supply and demand of building materials. And the Louvain algorithm is also improved to identify and characterize the network community relations based on the characteristics of this network. This paper also applies prefabricated components as an example for empirical research and obtains the following findings: (1) From 2017 to 2022, large- and medium-sized communities in the network gradually increase while small communities gradually decrease; the internal connectivity of large communities is higher than that of small communities; and the regional network also has the structural characteristics of the network. (2) The characteristics of geographic agglomeration gradually emerge in the individual communities in the supply-demand network of prefabricated components with the passage of time. Most of these communities are bounded by provinces, and large-scale communities are distributed in the eastern and southern coastal areas. Thus, this paper visualizes the supply and demand of construction materials to provide a theoretical basis and methodological support for the supply and demand of construction materials and the development of the construction industry.

13.
Diagnostics (Basel) ; 14(5)2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38472975

ABSTRACT

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

14.
Heliyon ; 10(4): e25821, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38375305

ABSTRACT

The global surge in energy demand, driven by technological advances and population growth, underscores the critical need for effective management of electricity supply and demand. In certain developing nations, a significant challenge arises because the energy demand of their population exceeds their capacity to generate, as is the case in Iraq. This study focuses on energy forecasting in Iraq, using a previously unstudied dataset from 2019 to 2021, sourced from the Iraqi Ministry of Electricity. The study employs a diverse set of advanced forecasting models, including Linear Regression, XGBoost, Random Forest, Long Short-Term Memory, Temporal Convolutional Networks, and Multi-Layer Perceptron, evaluating their performance across four distinct forecast horizons (24, 48, 72, and 168 hours ahead). Key findings reveal that Linear Regression is a consistent top performer in demand forecasting, while XGBoost excels in supply forecasting. Statistical analysis detects differences in models performances for both datasets, although no significant differences are found in pairwise comparisons for the supply dataset. This study emphasizes the importance of accurate energy forecasting for energy security, resource allocation, and policy-making in Iraq. It provides tools for decision-makers to address energy challenges, mitigate power shortages, and stimulate economic growth. It also encourages innovative forecasting methods, the use of external variables like weather and economic data, and region-specific models tailored to Iraq's energy landscape. The research contributes valuable insights into the dynamics of electricity supply and demand in Iraq and offers performance evaluations for better energy planning and management, ultimately promoting sustainable development and improving the quality of life for the Iraqi population.

15.
Environ Sci Pollut Res Int ; 31(2): 2090-2103, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38051491

ABSTRACT

The natural gas (NG) forms the sizeable portion of the primary energy consumption in Pakistan. However, its depleting domestic reserves and increasing demand is challenging to balance the supply-demand in the country. This paper investigates the relationship between NG consumption and driving factors using LMDI-STIRPAT PLSR framework. It is learned that fossil energy structure and per capita gross domestic product (GDP) are most influencing factors on NG consumption, followed by non-clean energy structure, energy intensity, and population. The factors were further modelled to forecast the future values of NG consumption for various scenarios. It is found that NG consumption would be 42.107 MTOE under the high development scenario which would be twice the baseline scenario. It is projected that indigenous NG production will fall from 4 to 2 billion cubic feet/day and demand will increase by 1.5 billion cubic feet/day. Therefore, an optimized strategy is required for a long-term solution to cater this increasing supply-demand.


Subject(s)
Economic Development , Natural Gas , Pakistan , Gross Domestic Product , Carbon Dioxide/analysis
16.
Chinese Health Economics ; (12): 44-48, 2024.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-1025221

ABSTRACT

The special demand medical services meet the diversified and personalized medical demands of the masses,and are the feedbacks of basic medical service.On the basis of searching and reviewing the policy documents on the price management of special demand medical service in public hospitals at the national level,it sorts out the key points and shortcomings of the current policy texts,and uses the thematic framework method and comparative analysis method to cover the application conditions for carrying out special demand,the scale control of special demand services the charging standard of special demand service,and the dimensions of the price supervision of special demands services.The specific provisions vary from provinces.Strengthening the management of the price of special medical services in public hospitals,in terms of system design,promoting the beneficial experience of typical provinces,and improving the project management program of the price of special medical services;in terms of implementation,the provision of special services in accordance with the published price items and the control of the size of the service,and the independent pricing and filing of the record.

17.
J Environ Manage ; 348: 119360, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37866180

ABSTRACT

Economic activities among multiple regions are always accompanied by carbon transfers. Analyzing coupling characteristics of economic activities and carbon transfer linkages based on the supply-demand relationships, can further reveal the networked structures of the multiregional interactions and common development trend of various industries, shedding light on carbon emission governance and high-quality development. This study advances novel coupling network models at the regional and industrial levels, and empirically analyzes the coupling characteristics in China based on the input-output data in 2012, 2015, and 2017. The findings reveal a noticeable decoupling process of economic activities and carbon transfers, but with distinct characteristics at the regional and industrial levels. The widening differences in coupling among provinces indicate increasing regional disparities. The decoupling process at the industrial level is primarily driven by the decreased connectivity in networked carbon transfers, instead of economic activities, reflecting the significant variations of industries' low-carbon development. The carbon decoupling process is notably more pronounced in supply-demand chains associated with export as the final use, compared to those linked with capital formation and final consumption. Analysis of coupling characteristics and the identification of decoupling evolution process enhance our understanding of the relationship between economic activities and carbon transfer, and may provide valuable insights for prioritizing actions and achieving efficient carbon emission reduction.


Subject(s)
Carbon , Economic Development , Carbon/analysis , Carbon Dioxide/analysis , Industry , China
18.
Front Physiol ; 14: 1172834, 2023.
Article in English | MEDLINE | ID: mdl-37538372

ABSTRACT

This study examined changes in interstitial PO2, which allowed calculation of VO2 during periods of rest, muscle contraction and recovery using an in situ rat spinotrapezius muscle preparation. The PO2 was measured using phosphorescence quenching microscopy and the muscle VO2 was calculated as the rate of O2 disappearance during brief periods of muscle compression to stop blood flow with a supra-systolic pressure. The PO2 and VO2 measurements were made during "5 s compression and 15 s recovery" (CR) cycles. With all three stimulation frequencies, 1, 2 and 4 Hz, the fall in interstitial PO2 and rise in VO2 from resting values occurred within the first 20 s of contraction. The PO2 during contraction became lower as stimulation frequency increased from 1 to 4 Hz. VO2 was higher at 2 Hz than at 1 Hz contraction. With cessation of stimulation, PO2 began increasing exponentially towards baseline values. After 1 and 2 Hz contraction, the fall in muscle VO2 was delayed by one CR cycle and then exponentially decreased towards resting values. After 4 Hz stimulation, VO2 increased for 2 cycles and then decreased. The post-contraction transients of PO2 and VO2 were not synchronous and had different time constants. With further analysis two distinct functional responses were identified across all stimulation frequencies having PO2 during contraction above or below 30 mmHg. The corresponding VO2 responses were different - for "high" PO2, muscle VO2 reached high levels, while for the "low" PO2 data set muscle VO2 remained low. Recovery patterns were similar to those described above. In summary, local microscopic PO2 and VO2 were measured in resting and contracting muscle in situ and the post-contraction transients of PO2 and VO2 were all much slower than the onset transients.

19.
Sci Total Environ ; 902: 165918, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37544455

ABSTRACT

Regional integration is a development strategy that synergizes various components as a whole to maximize overall benefits. The natural heterogeneity and fluidity of ecosystem service (ES) make it a promising target for regional integration. However, the current focus on regional integration was more on the socio-economic factors rather than ecological resources, and the understanding of the supply-demand relationship and potential flow of ecosystem services was still limited. Therefore, we attempted to interpret ecological integration management by linking ES budgets, bundles, and flows in this study. The results showed that the spatial mismatches of ESs supply-demand were observed in all six selected ES types. Most of the ESs deficit regions were concentrated in urban centers, while ES surplus regions were scattered in surrounding rural areas. Multiple heterogeneous ES resources could ideally benefit an additional 0.13-4.84 million people in 9-70 townships through potential ES flows under ecological integration management. Therefore, we connected the service provisioning areas (SPAs) and service beneficiary areas (SBAs) with three types of ES flows and drew the potential provider-beneficiary relationship networks at the townships/bundles scale, demonstrating the interactive relationship of ecological integration within the region. On this basis, we also proposed the applicability matrix of governance tools for the first time according to the type of ES flows, and then put forward the corresponding governance opinions around the two aspects of "improving ES budges within clusters" and "strengthening ES flow among clusters". This study provided an ecological perspective for understanding regional integration, and relevant conclusions can inform environmental policy priorities for sustainable decision-making in urbanized areas.

20.
Sci Total Environ ; 887: 164205, 2023 Aug 20.
Article in English | MEDLINE | ID: mdl-37187399

ABSTRACT

Climate change and human activities can have an impact on the supply and demand of water-related ecosystem services (WRESs) in the Asian water tower (AWT) and its downstream area, which is closely related to the production and livelihoods of billions of people. However, few studies have taken the AWT and its downstream area as a whole to assess the supply-demand relationship of WRESs. This study aims to assess the future trends of the supply-demand relationship of WRESs in the AWT and its downstream area. Here, the supply-demand relationship of WRESs in 2019 was assessed using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and socio-economic data. Then, future scenarios were selected under the framework of the Scenario Model Intercomparison Project (ScenarioMIP). Finally, trends in the supply-demand of WRESs were analysed at multiple scales from 2020 to 2050. The study found that the supply-demand imbalance of WRESs in the AWT and its downstream area will continue to intensify. The area with imbalance intensification was 2.38 × 106 km2 (61.7 %). The supply-demand ratio of WRESs will decline significantly under different scenarios (p < 0.05). The main reason for the imbalance intensification in WRESs is the constant growth of human activities, with a relative contribution of 62.8 %. Our findings suggest that in addition to the pursuit of climate mitigation and adaptation, attention should also be paid to the impact of rapid human activity growth on the supply-demand imbalance of WRESs.

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