Search

Accurate estimates of soil organic carbon (SOC) stocks are important in understanding terrestrial carbon cycling. Based on the fundamental theorem of surfaces, an alternative method, high accuracy surface modelling (HASM) combined with soil depth information was applied to predict the spatial pattern of SOC stocks in Hebei Province, China. In this study, we collected 434 soil samples and key environmental covariates related to soil-forming factors (soil, climate, organisms, topography, and soil depth information) in the study area, and compared the accuracy of 16 spatial prediction models (including single models, hybrid models, and HASM combined with single or hybrid models) on the spatial distribution of SOC stocks. The results confirmed that the method of HASM combined with the generalized additive model (GAM) with soil depth covariate (HASM_GAMD) achieved a better performance than other methods at soil depths of 0–30, 0–100 and 0–200 cm. The root-mean-square error and coefficient of determination values of predicting the spatial pattern of SOC stocks by the HASM_GAMD model demonstrated a 43% and 49% improvement, respectively, compared with models without depth information. The prediction uncertainty of the HASM_GAMD model based on 90% prediction interval was lower than that of other models. The HASM_GAMD model excels in addressing not only the nonlinear relationship between covariates and SOC stocks, but also in incorporating point observation data that varies with soil depth. Furthermore, the model conducts modelling by integrating surface and optimal control theories. Results obtained from the HASM_GAMD demonstrated that the SOC stocks in Hebei Province amounted to 1449.08 Tg C. Our study introduces an alternative model for modelling of SOC stocks and our findings are a valuable reference for assessing carbon stocks in Hebei Province to support sustainable land management and climate change mitigation. • We applied a surface modeling method to predict soil organic carbon stocks. • Combining surface modeling methods with soil depth can improve the performance. • Soil organic carbon stocks are 1449.08 Tg C (60% in >30 cm soil layer) in study area. [ABSTRACT FROM AUTHOR]

Background: Giant Juncao is often used as feed for livestock because of its huge biomass. However, drought stress reduces forage production by affecting the normal growth and development of plants. Therefore, investigating the molecular mechanisms of drought tolerance will provide important information for the improvement of drought tolerance in this grass. Results: A total of 144.96 Gb of clean data was generated and assembled into 144,806 transcripts and 93,907 unigenes. After 7 and 14 days of drought stress, a total of 16,726 and 46,492 differentially expressed genes (DEGs) were observed, respectively. Compared with normal irrigation, 16,247, 23,503, and 11,598 DEGs were observed in 1, 5, and 9 days following rehydration, respectively. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed abiotic stress-responsive genes and pathways related to catalytic activity, methyltransferase activity, transferase activity, and superoxide metabolic process. We also identified transcription factors belonging to several families, including basic helix-loop-helix (bHLH), WRKY, NAM (no apical meristem), ATAF1/2 and CUC2 (cup-shaped cotyledon) (NAC), fatty acyl-CoA reductase (FAR1), B3, myeloblastosis (MYB)-related, and basic leucine zipper (bZIP) families, which are important drought-rehydration-responsive proteins. Weighted gene co-expression network analysis was also used to analyze the RNA-seq data to predict the interrelationship between genes. Twenty modules were obtained, and four of these modules may be involved in photosynthesis and plant hormone signal transduction that respond to drought and rehydration conditions. Conclusions: Our research is the first to provide a more comprehensive understanding of DEGs involved in drought stress at the transcriptome level in Giant Juncao with different drought and recovery conditions. These results may reveal insights into the molecular mechanisms of drought tolerance in Giant Juncao and provide diverse genetic resources involved in drought tolerance research. [ABSTRACT FROM AUTHOR]

The miniaturization of transistors led to advances in computers mainly to speed up their computation. Such miniaturization has approached its fundamental limits. However, many practices require better computational resources than the capabilities of existing computers. Fortunately, the development of quantum computing brings light to solve this problem. We briefly review the history of quantum computing and highlight some of its advanced achievements. Based on current studies, the Quantum Computing Advantage (QCA) seems indisputable. The challenge is how to actualize the practical quantum advantage (PQA). It is clear that machine learning can help with this task. The method used for high accuracy surface modelling (HASM) incorporates reinforced machine learning. It can be transformed into a large sparse linear system and combined with the Harrow-Hassidim-Lloyd (HHL) quantum algorithm to support quantum machine learning. HASM has been successfully used with classical computers to conduct spatial interpolation, upscaling, downscaling, data fusion and model-data assimilation of eco-environmental surfaces. Furthermore, a training experiment on a supercomputer indicates that our HASM-HHL quantum computing approach has a similar accuracy to classical HASM and can realize exponential acceleration over the classical algorithms. A universal platform for hybrid classical-quantum computing would be an obvious next step along with further work to improve the approach because of the many known limitations of the HHL algorithm. In addition, HASM quantum machine learning might be improved by: (1) considerably reducing the number of gates required for operating HASM-HHL; (2) evaluating cost and benchmark problems of quantum machine learning; (3) comparing the performance of the quantum and classical algorithms to clarify their advantages and disadvantages in terms of accuracy and computational speed; and (4) the algorithms would be added to a cloud platform to support applications and gather active feedback from users of the algorithms. [ABSTRACT FROM AUTHOR]

[Display omitted] • POC accounts for about a third of the total cropland SOC. • Cropland type is the dominant role of soil POC and MAOC. • Temperature effects on SOC fractions are cropland type-dependent. • Temperature effects decline after removing correlations with net primary productivity. • Main controls of soil POC and MAOC vary with cropland types. Agricultural land use and temperature change can profoundly affect soil organic carbon (SOC), but their combined effects on regulating cropland SOC fractions over broad geographic scales remain poorly understood. Based on 871 topsoil (0–20 cm) samples collected from the Sichuan Basin of China, we used random forest model and partial correlations analysis to explore how the functionally distinct SOC fractions, including particulate and mineral-associated organic C (POC and MAOC), are affected by both agricultural land use and temperature over a large scale. The results show that POC accounts for 32.54 % of the total cropland SOC and soils with high SOC contents have larger proportions of POC. Cropland type is the dominant control of the two SOC fractions and regulates the impacts of other factors. The contents of soil POC and MAOC in dryland are much lower than that in paddy field and dryland-paddy rotation land. Significant correlations between mean annual temperature and the two SOC fractions are only found in dryland and dryland-paddy rotation land, while mean annual temperature has no impact on both POC and MAOC in paddy field. Meanwhile, the correlation coefficients between mean annual temperature and POC and MAOC for dryland decreased by 61.90 % and 69.23 %, respectively, and for dryland-paddy rotation land decreased by 28.00 % and 14.29 %, respectively, after removing correlations with net primary productivity. Additionally, correlation between mean annual temperature and POC is slightly higher than that between mean annual temperature and MAOC in dryland, while the reverse in dryland-paddy rotation land. These results suggest that the temperature effects on POC and MAOC are cropland type-dependent. To accurately predicting future cropland SOC change and reliably evaluate the potential contribution of cropland soil C sequestration, fraction-specific control mechanisms related to cropland type should be sufficiently considered in carbon models. [ABSTRACT FROM AUTHOR]

We propose a fundamental theorem for eco-environmental surface modelling (FTEEM) in order to apply it into the fields of ecology and environmental science more easily after the fundamental theorem for Earth's surface system modeling (FTESM). The Beijing-Tianjin-Hebei (BTH) region is taken as a case area to conduct empirical studies of algorithms for spatial upscaling, spatial downscaling, spatial interpolation, data fusion and model-data assimilation, which are based on high accuracy surface modelling (HASM), corresponding with corollaries of FTEEM. The case studies demonstrate how eco-environmental surface modelling is substantially improved when both extrinsic and intrinsic information are used along with an appropriate method of HASM. Compared with classic algorithms, the HASM-based algorithm for spatial upscaling reduced the root-mean-square error of the BTH elevation surface by 9 m. The HASM-based algorithm for spatial downscaling reduced the relative error of future scenarios of annual mean temperature by 16%. The HASM-based algorithm for spatial interpolation reduced the relative error of change trend of annual mean precipitation by 0.2%. The HASM-based algorithm for data fusion reduced the relative error of change trend of annual mean temperature by 70%. The HASM-based algorithm for model-data assimilation reduced the relative error of carbon stocks by 40%. We propose five theoretical challenges and three application problems of HASM that need to be addressed to improve FTEEM. [ABSTRACT FROM AUTHOR]

In the past decades, the greenhouse gas (GHG) emissions from pig production in China have been increasing rapidly, which has become a huge challenge in fulfilling China's "carbon neutral" commitment. However, few studies have focused on reducing the GHG emissions from pig production in view of households' pork consumption. This study analyzed the temporal and spatial pattern of the GHG emissions from pig production in China in 2001–2020 through geographical information system, optimized the pig production in China, and estimated the potential GHG emissions reduction from pig production in China in 2020 through spatial analysis based on pork surplus or deficit. Results show that the temporal and spatial pattern of the GHG emissions from pig production and its proportion in the total GHG emissions from livestock production in China in 2001–2020 varied differently at the province level and conformed to the "Hu Huanyong Line" mode. The largest and smallest GHG emissions from pig production were 108.93 million tons (MT) in 2014 and 78.10 MT in 2020, respectively. The largest and smallest proportions of GHG emissions from pig production in the total GHG emissions from livestock production were 77.52% in Zhejiang in 2013 and 0.13% in Tibet in 2009, respectively. Moreover, a potential optimization scheme of pig production in China in 2020 was provided and a method of GHG emissions reduction from pig production is proposed. The results indicate that the total potential GHG emissions reduction from pig production on the basis of households' pork consumption could reach 35.21 MT, accounting for 45.09% of the total GHG emissions from pig production and 10.27% of the total GHG emissions from livestock production in China in 2020. These findings are useful in the spatial layout planning of pig production, agricultural GHG reduction, and global warming mitigation. [ABSTRACT FROM AUTHOR]

Producing biogas from agricultural waste by using a household biogas digester has a critical role in increasing energy supply and reducing greenhouse gas emissions in rural areas. However, only a few studies have analyzed the type of animal husbandry and planting that influence household biogas. This paper analyzes the spatial-temporal distribution of household biogas and its proportion in the total biogas produced in rural China from 2009 to 2018. The correlation between household biogas in rural China and animal husbandry and planting from 2009 to 2018 is also examined. The types of animal husbandry and planting that influence household biogas are then respectively determined via ordinary least squares and geographically weighted regression. Results show that the spatial-temporal distributions of household biogas with maximum and minimum values of 1.384 × 1010 m3 in 2011 and 0.8420 × 1010 m3 in 2018, respectively and its proportion with maximum and minimum values of 94.83% in 2009 and 75.07% in 2018, respectively significantly vary and show a declining trend from 2009 to 2018. The number of cattle and pigs is identified as the main animal husbandry factor that influences household biogas, whereas the planting areas of vegetables, fiber, and tobacco were identified to be the main planting factors. Considering fitting effects, R2 and adjusted R2 values of 0.8620 and 0.8100 obtained by geographically weighted regression respectively, were higher than those of ordinary least squares (0.6480 and 0.6220, respectively), respectively in animal husbandry factors, whereas R2 and adjusted R2 values of 0.8400 and 0.7990 obtained by geographically weighted regression, respectively, were higher than those of ordinary least squares (0.7190 and 0.6880, respectively) in planting factors. These results provide a reference for planning the production of biogas and the utilization of agricultural waste. [Display omitted] • Reveal spatial-temporal differences in the household biogas. • Show spatial-temporal distribution of proportion of household biogas in total biogas. • Determine correlation of household biogas with types of animal husbandry and planting. • Identify types of animal husbandry and planting influence household biogas. • Reveal spatial heterogeneity of the type of animal husbandry and planting. [ABSTRACT FROM AUTHOR]

• Construct a suitability evaluation system for centralized treatment center of livestock excreta. • Build a spatial relation between centralized treatment center of livestock excreta and farmland. • Determine collection points of livestock excreta based on the spatial clustering results of livestock farm and median center. • Select a spatial site for centralized treatment center of livestock excreta. At present, processing substantial livestock excreta produced by numerous concentrated small–middle-type livestock farms (SMLFs) has been a major problem of livestock farm owners and government departments. To solve this problem, this study established a suitability evaluation system for the spatial layout of a centralized treatment center of livestock excreta (CTCLE). On this basis, combined with the collection points of livestock excreta (CPLEs) determined by spatial clustering algorithm and median center and matched farmlands, the spatial site selection of CTCLE was analyzed using the geographic information system (GIS) spatial analysis method and GIS component development technology. Practical application research was conducted in Nantong Town, and pigs were used as examples. Results showed that most regions of Nantong Town belong to forbidden and unsuitable regions, accounting for 68.63% of the total region of the town. A small part of a highly suitable region (6.428 ha) was determined as potential CTCLE. A total of 839 SMLFs were divided into 61 CPLEs, and the spatial relation between potential CTCLEs and farmlands was established. The spatial sites of 11 CTCLEs in Nantong Town, Minhou County were selected, and the total nitrogen and phosphorus of livestock excreta to be reduced were estimated. The results will provide a scientific basis for the utilization of livestock excreta and the spatial layout planning of livestock and poultry breeding. [ABSTRACT FROM AUTHOR]

• Establish a comprehensive evaluation index system for the comparative advantages of dairy farming. • Build a comprehensive evaluation model on comparative advantages of dairy farming. • Analyze spatial-temporal of comparative advantage of dairy farming. • Identify advantage region of dairy farming. High cost and low milk yield per dairy cow are current problems mainly faced by dairy farms in China. Thus, optimizing the regional layout and integrating the advantages to enhance the competitiveness of dairy farming in China is necessary. However, existing studies on comparative advantage analysis of dairy breeding have a relatively single perspective. Therefore, comprehensively identifying the advantage area of dairy farming is difficult. This study established a comprehensive evaluation model of the comparative advantages of dairy farming considering basic, technical, economic, and feed resource indexes using linear weighted and entropy weight methods. On this basis, the spatial–temporal analysis of the comprehensive evaluation on comparative advantages of dairy farming from 2013 to 2017 was performed using Geographic Information System(GIS). Finally, the advantage areas of dairy farming were identified. Results demonstrated that the highest average comprehensive evaluation value was 0.6017 in Inner Mongolia Autonomous Region, followed by 0.5355 in Ningxia Hui Autonomous Region and 0.1786 in Anhui Province. Furthermore, the advantage areas of dairy farming were identified including Inner Mongolia Autonomous Region, Beijing Municipality, Heilongjiang Province, Shanghai Municipality, Xinjiang Uygur Autonomous Region, Tianjin Municipality, Liaoning Province, Shanxi Province and Ningxia Hui Autonomous These findings provide references for the spatial layout of dairy farming, spatial allocation of production resources, and sustainable development of animal husbandry. [ABSTRACT FROM AUTHOR]

• ET characteristics were investigated taking the watershed as an integral research object. • Quantitative variation of ET was given at typical ecosystems, oasis-desert system and watershed scales. • The results can be applied to similar climatic and landscape endorheic basins. The Heihe River Basin (HRB), with unique landscapes and coexisting cold and arid regions, is the second largest endorheic basin in northwestern China. The Heihe integrated observatory network was established in 2007, which included multi-element, multiscale, distributed, and incorporating satellite-airborne-ground based observations via Internet of Things technology; these observations span the main land cover of the basin. This observatory provides a great opportunity to analyze the spatiotemporal variation in evapotranspiration (ET) in the HRB, and ET characteristics were investigated on three scales (typical ecosystems, oasis-desert systems, watershed) taking the HRB as a research object. The average annual ET in typical ecosystems is approximately 380–530 mm upstream (alpine meadow, Qinghai spruce, shrub), 640–1000 mm midstream (maize, wetland), 610–680 mm downstream (riparian forest), and 190 mm and 50 mm in midstream and downstream desert surfaces, respectively. The ET from plant surfaces is strongly controlled by available energy in upstream and midstream regions, while it is controlled by vapor pressure deficit (VPD) and surface conductance downstream. The ET in oasis and desert systems is characterized by three gradients: plant, residential area/barren land, and desert, with a maximum difference of annual ET more than 500 mm. This difference is primarily caused by variations of soil moisture among different underlying surfaces. For watershed ET, higher ET was observed upstream, and it decreased from midstream to downstream, with the highest values in the oasis. The annual ET in the main plant surfaces was approximately 500–700 mm, 600–800 mm, and 600–700 mm in the up-, mid-, and downstream regions, respectively, while the ET was approximately 100–250 mm and 50–200 mm in desert and barren or sparsely vegetation surfaces in the mid- and downstream regions, respectively. The spatiotemporal variations of ET were primarily influenced by land cover, soil moisture, vegetation condition and available energy. The results improve our understanding of the spatiotemporal variations in ET in the HRB and apply to comparable endorheic basins with similar climatic and landscape conditions. [ABSTRACT FROM AUTHOR]

The optimization of the spatial layout of animal husbandry has great significance for the sustainable development of animal husbandry. However, limited research has focused on the optimization of the spatial layout of animal husbandry based on comprehensive competitive advantage evaluation and nutrient balance between planting and breeding. This study established a comprehensive competitive advantage evaluation model of animal husbandry. Based on this model, we performed comprehensive competitive advantage evaluation of animal husbandry. We further calculated the land-carrying capacity index of animal manure and potential land-carrying capacity of animal according to the principle of nutrient balance. Finally, the spatial layout of animal husbandry was optimized using Geographic Information System spatial analysis. Results showed that Harbin had obvious comprehensive competitive advantage in pig, cattle, sheep, and poultry breeding. Daqing had obvious comprehensive competitive advantage in cattle and sheep breeding. The land-carrying capacity index of animal manure of Daxing'anling constantly exceeded 1. The potential land-carrying capacity of animal in Heilongjiang province was uneven, and most regions in Heilongjiang province had development potential of animal husbandry. The optimized target regions of the spatial layout of pig, cattle, sheep, and poultry breeding were all Harbin. A total of 77 956.03 pig equivalent in Daxing'anling was recommended to be transferred to Harbin. Our results are useful for the spatial layout of animal husbandry, environmental pollution prevention from animal husbandry, and optimization of animal products structure., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Livestock farms produce a large amount of livestock manure, which, if not disposed of properly, will become an environmental pollution source. However, limited research has been conducted on identifying livestock farms with a potential risk of environmental pollution. In this study, a model for returning livestock manure to cultivated land was constructed. Livestock manure was returned to cultivated land, and the amount of surplus livestock manure nutrients, including nitrogen and phosphorus, in livestock farms was calculated with pig manure as an example. Then, livestock farms with a potential risk of environmental pollution in Shanggan Town and part of Xiangqian Town in Fuzhou City were identified using phosphorus as an index. Results showed that the spatial distributions of nitrogen and phosphorus from pig manure in the cultivated land varied. All cultivated lands exhibited the maximum carrying capacity for phosphorus, and 1811 cultivated lands exhibited potential nitrogen carrying capacity. A total of 13,958.997 kg of phosphorus from pig manure in 144 livestock farms could not be disposed to cultivated lands. In all, 144 livestock farms with surplus phosphorus from pig manure were identified as potential environmental pollution sources. These findings can serve as a scientific basis for the utilization of livestock manure, prevention of environmental pollution caused by livestock farms, and layout planning of livestock farms., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biogas produced from agricultural waste can have potential benefits, such as offer clean renewable energy, protect the ecological environment, and reduce CO 2 emission. However, few studies have been conducted on the biogas potential from agricultural waste and its CO 2 emission reduction at the county level. Herein, the biogas potential from agricultural waste was calculated, and its spatial distribution in Hubei Province in 2017 was determined using a geographic information system. Then, an evaluation model for the competitive advantage of the biogas potential from agricultural waste was established using entropy weight and linear weighting methods. Moreover, the space partition of the biogas potential from agricultural waste was obtained through hot spot analysis. Lastly, the standard coal equivalent of biogas, the equivalent of coal consumption of biogas, and the CO 2 emission reduction based on the space partition result were estimated. Results showed that the total and average biogas potentials from agricultural waste in Hubei Province were 18,498,317,558.54 and 222,871,295.89 m 3 , respectively. Qianjiang City, Jianli County, Xiantao City, and Zaoyang City had a high competitive advantage in the biogas potential from agricultural waste. The CO 2 emission reduction of the biogas potential from agricultural waste was mainly in classes I and II., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background and Objectives: Laparoscopic colorectal surgery causes a lower stress response than open surgery. Adiponectin is mainly derived from adipocytes and has antidiabetic, antioxidative, and anti-inflammatory capabilities. The objective of the present study was to investigate the protein expression of adiponectin in adipose tissue, and the serum levels of adiponectin, oxidative stress markers and proinflammatory factors during laparoscopic colorectal surgery and open surgery periods., Methods: Forty patients aged 60 to 80, with American Society of Anesthesiologists (ASA) I ~ II who underwent radical resection of colorectal cancer were recruited to the study. Laparoscopic group and open group included 20 patients each. Mesenteric adipose tissue and venous blood before (T1) and at the end (T2) of surgery were collected to examine adiponectin levels, and venous blood was collected to examine serum levels of oxidative stress related markers (superoxide dismutase (SOD), glutathione (GSH), lipid peroxide (LPO), malondialdehyde (MDA)), and inflammation-related factors (interleukin (IL)-1β, interleukin (IL)-6, tumor necrosis factor-α (TNF-α))., Results: Protein and serum levels of adiponectin were analyzed, and adiponectin levels were significantly increased at T2 than T1 in the laparoscopic surgery, while adiponectin levels were significantly higher in the laparoscopic surgery than in the open surgery at T2. In addition, the serum levels of SOD and GSH were significantly higher in the laparoscopic surgery than in open surgery at T2. However, the serum levels of LPO, TNF-α, IL-1β, and IL-6 were significantly lower in the laparoscopic group than in open group at T2., Conclusion: Laparoscopic surgery induced higher levels of adiponectin in both adipose tissue and the bloodstream. Oxidative stress and the inflammatory response were lower during laparoscopic colorectal surgery than during conventional open surgery. These data suggest that adipose tissue may alleviate the stress response during laparoscopic surgery by releasing adiponectin in patients with colorectal cancer., (© 2021. The Author(s).)

Ambient ozone (O 3 ) concentrations have shown an upward trend in China and its health hazards have also been recognized in recent years. High-resolution exposure data based on statistical models are needed. Our study aimed to build high-performance random forest (RF) models based on training data from 2013 to 2017 in the Beijing-Tianjin-Hebei (BTH) region in China at a 0.01 ° × 0.01 ° resolution, and estimated daily maximum 8h average O 3 (O 3 -8hmax) concentration, daily average O 3 (O 3 -mean) concentration, and daily maximum 1h O 3 (O 3 -1hmax) concentration from 2010 to 2017. Model features included meteorological variables, chemical transport model output variables, geographic variables, and population data. The test-R 2 of sample-based O 3 -8hmax, O 3 -mean and O 3 -1hmax models were all greater than 0.80, while the R 2 of site-based and date-based model were 0.68-0.87. From 2010 to 2017, O 3 -8hmax, O 3 -mean, and O 3 -1hmax concentrations in the BTH region increased by 4.18 μg/m 3 , 0.11 μg/m 3 , and 4.71 μg/m 3 , especially in more developed regions. Due to the influence of weather conditions, which showed high contribution to the model, the long-term spatial distribution of O 3 concentrations indicated a similar pattern as altitude, where high concentration levels were distributed in regions with higher altitude., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Introduction and Objectives: Dexmedetomidine is a highly selective alpha-2 adrenoceptor agonist that has sedative and analgesic properties and myocardial protective effects. However, the mechanism underlying the protective effect of dexmedetomidine on cardiomyocytes remains unknown. This study mainly aimed to investigate the effects of dexmedetomidine on the generation of reactive oxygen species (ROS) in cardiomyocytes and whether it inhibits the apoptosis of cardiomyocytes by affecting antioxidant enzyme expression., Methods: Neonatal rat cardiomyocytes were pretreated with dexmedetomidine (100 nM) for 24 h. The cardiomyocytes were then incubated with 200 μM hydrogen peroxide solution (H 2 O 2 ) for 4 h. PCR assay was used to determine the mRNA expression of antioxidant enzymes. Western blot assay was used to determine the protein expression of antioxidant enzymes. Fluorescence microscopy with the MitoSOX probe was used to detect the formation of ROS in cardiomyocytes, and fluorescence-activated cell sorting with annexin V/PI was used to determine the number of apoptotic cardiomyocytes., Results: Dexmedetomidine reduced ROS generation and antioxidant enzymes levels in cardiomyocytes before H 2 O 2 stimulation (p<0.05). However, ROS generation and apoptosis in cardiomyocytes were significantly increased after H 2 O 2 treatment, and dexmedetomidine pretreatment markedly inhibited the changes (p<0.05)., Conclusion: For the first time, to the best of our knowledge, our study shows that dexmedetomidine has a protective effect on cardiomyocytes through inhibition of ROS-induced apoptosis, and more importantly, this effect is independent of antioxidant enzyme mRNA and protein expression., (Copyright © 2021 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.)