Carbon dioxide

二氧化碳
  • 文章类型: Journal Article
    锥形束计算机断层扫描(CBCT)广泛用于标准和复杂的血管内主动脉介入的技术评估。在CBCT成像中使用碘化造影剂可能会提供有用的额外信息;然而,这也增加了程序对比剂剂量,这可能会导致肾功能恶化,和辐射暴露。我们描述了二氧化碳(CO2)增强的CBCT用于标准和复杂的血管内主动脉修复的技术评估的技术和可行性。根据我们的经验,CO2-CBCT没有相关的不良事件,并提供令人满意的成像质量来评估移植物的完整性。血管通畅,并且在严重慢性肾功能不全的情况下安全地进行。
    Cone-beam computed tomography (CBCT) is widely used for the technical assessment of standard and complex endovascular aortic interventions. Use of iodinated contrast in CBCT imaging might provide useful additional information; however, this also increases the procedural contrast dose, which may cause renal function deterioration, and the radiation exposure. We describe the technique and feasibility of carbon-dioxide (CO2)-enhanced CBCT for the technical assessment of standard and complex endovascular aortic repair. In our experience CO2-CBCT had no related adverse events and provided satisfactory imaging quality to assess endograft integrity, vessels patency, and was safely performed in case of severe chronic renal insufficiency.
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  • 文章类型: News
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  • 文章类型: Journal Article
    近几十年来,新型治疗剂的不利溶解度被认为是制药工业中的重要挑战。超临界二氧化碳(SCCO2)被称为绿色,成本效益高,高性能,和有希望的溶剂,以开发低溶解度的药物,以提高其治疗效果。这项研究的主要目的是通过人工智能(AI)改进和修改不同的预测模型,以估计奥沙普嗪在SCCO2系统中溶解度的优化值。在本文中,在溶解度数据集上选择了三种不同的模型来开发模型.压力(巴)和温度(K)是每个矢量的两个输入,并且每个载体具有一个输出(溶解度)。选定的模型包括NU-SVM,线性SVM,决策树(DT)。通过超参数优化模型,并应用标准指标进行评估。考虑R平方度量,NU-SVM,线性SVM,和DT的得分分别为0.994、0.854和0.950。此外,它们的RMSE错误率分别为3.0982E-05、1.5024E-04和1.1680E-04。根据所做的评估,NU-SVM被认为是最精确的方法,最优值可以总结为(T=336.05K,P=400.0bar,溶解度=0.00127)采用该模型。图4.
    In recent decades, unfavorable solubility of novel therapeutic agents is considered as an important challenge in pharmaceutical industry. Supercritical carbon dioxide (SCCO2) is known as a green, cost-effective, high-performance, and promising solvent to develop the low solubility of drugs with the aim of enhancing their therapeutic effects. The prominent objective of this study is to improve and modify disparate predictive models through artificial intelligence (AI) to estimate the optimized value of the Oxaprozin solubility in SCCO2 system. In this paper, three different models were selected to develop models on a solubility dataset. Pressure (bar) and temperature (K) are the two inputs for each vector, and each vector has one output (solubility). Selected models include NU-SVM, Linear-SVM, and Decision Tree (DT). Models were optimized through hyper-parameters and assessed applying standard metrics. Considering R-squared metric, NU-SVM, Linear-SVM, and DT have scores of 0.994, 0.854, and 0.950, respectively. Also, they have RMSE error rates of 3.0982E-05, 1.5024E-04, and 1.1680E-04, respectively. Based on the evaluations made, NU-SVM was considered as the most precise method, and optimal values can be summarized as (T = 336.05 K, P = 400.0 bar, solubility = 0.00127) employing this model. Fig 4.
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  • 文章类型: Journal Article
    人类活动导致大气中二氧化碳(CO2)浓度升高。虽然这种增加本身可能有利于一些作物的生长,它带有影响作物营养状况的警告。这里,我们提出了对必需元素(Cu,Fe,Mn,Zn,Mo,Ni)和非必需(Ba,Cd,Cr,Hg,Pb,和Sr)重金属对CO2升高的响应,基于对1216个成对观测值的荟萃分析。主要研究结果如下:(1)CO2浓度升高导致Cu浓度降低,Fe,Mn,和作物中的锌;(2)上述减少的程度因植物种类而异,在谷物中最明显,然后在豆类和蔬菜中最明显;(3)非必需(有毒)金属的积累减少不太明显,可能导致植物中不利的必需/非必需金属比例;(4)上述影响将对人类健康产生重大影响,加剧了人类饮食中缺乏铁和锌造成的“隐性饥饿”的影响。本文还分析了营养获取的机理基础(在生理和分子水平上),并呼吁政府政策的变化,以增加植物育种者的努力,以创造具有改善的营养利用效率的基因型,同时将其转运与非必需(有毒)重金属。
    Human activities led to elevation in carbon dioxide (CO2) concentrations in atmosphere. While such increase per se may be beneficial for the growth of some crops, it comes with a caveat of affecting crop nutritional status. Here, we present a comprehensive analysis of changes in concentration of essential (Cu, Fe, Mn, Zn, Mo, Ni) and non-essential (Ba, Cd, Cr, Hg, Pb, and Sr) heavy metals in response to elevated CO2, drawing on a meta-analysis of 1216 paired observations. The major findings are as follows: (1) Elevated CO2 leads to reduced concentrations of Cu, Fe, Mn, and Zn in crops; (2) the extent of above reduction varies among plants species and is most pronounced in cereals and then in legumes and vegetables; (3) reduction in accumulation of non-essential (toxic) metals is less pronounced, potentially leading to an unfavorable essential/non-essential metal ratio in plants; (4) the above effects will come with significant implication to human health, exacerbating effects of the \"hidden hunger\" caused by the lack of Fe and Zn in the human diets. The paper also analyses the mechanistic basis of nutrient acquisition (both at physiological and molecular levels) and calls for the changes in the governmental policies to increase efforts of plant breeders to create genotypes with improved nutrient use efficiency for essential micronutrients while uncoupling their transport from non-essential (toxic) heavy metals.
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  • 文章类型: Journal Article
    In East Asia, where several countries are among the top emitters of carbon dioxide globally, the need to address the dual challenges of reducing carbon footprints and ensuring health security is paramount. Against this backdrop, this study used a descriptive analysis to provide a comparative assessment of the carbon footprints and the level of health security in East Asia using secondary data, sourced from the World Development Indicators. The findings from the study show that it is only North Korea that its average carbon footprint of every person is less than 2.3 tons. However, China, Japan, Mongolia and South Korea are currently lagging behind in meeting the SDG 13 target. Meanwhile, North Korea recorded the highest incidence of tuberculosis in the region. Despite the fact that South Korea and Japan were the highest emitter of CO2, the duo had the lowest under five mortality, infant mortality, incidence of TB alongside the highest life expectancies which surpassed the regional performance. In view of the above, the policymakers in Asia and the rest of the countries with health insecurity should emulate the policymakers in Japan and South Korea by making adequate investment in health, education, and standard of living of their citizens.
    En Asie de l’Est, où plusieurs pays comptent parmi les plus grands émetteurs de dioxyde de carbone au monde, la nécessité de relever le double défi de réduire l’empreinte carbone et d’assurer la sécurité sanitaire est primordiale. Dans ce contexte, cette étude a utilisé une analyse descriptive pour fournir une évaluation comparative des empreintes carbone et du niveau de sécurité sanitaire en Asie de l’Est à l’aide de données secondaires provenant des indicateurs de développement mondial. Les résultats de l’étude montrent que seule la Corée du Nord a une empreinte carbone moyenne par personne inférieure à 2,3 tonnes. Cependant, la Chine, le Japon, la Mongolie et la Corée du Sud sont actuellement à la traîne dans la réalisation de l’ODD 13. Pendant ce temps, la Corée du Nord a enregistré la plus forte incidence de tuberculose dans la région. Bien que la Corée du Sud et le Japon soient les plus grands émetteurs de CO2, ces deux pays ont les taux de mortalité des moins de cinq ans, de mortalité infantile et d\'incidence de tuberculose les plus faibles, ainsi que les espérances de vie les plus élevées, dépassant les performances régionales. Compte tenu de ce qui précède, les décideurs politiques d’Asie et du reste des pays souffrant d’insécurité sanitaire devraient imiter les décideurs politiques du Japon et de la Corée du Sud en investissant de manière adéquate dans la santé, l’éducation et le niveau de vie de leurs citoyens.
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  • 文章类型: Journal Article
    该研究表征了2020年12月至2021年11月之间温室气体(GHG)通量(CO2,CH4和N2O)的时空变化及其在印度喜马拉雅山麓亚热带湿地中的调节驱动因素。五个不同的栖息地(沼泽森林的M1草皮表面,M2-沼泽森林的平原表面,M3-带有小草的沼泽表面,M4-沼泽土地,拥有密集的大型植物,和具有稀疏植物的M5沼泽土地)进行了研究。我们进行了温室气体通量的原位测量,小气候(AT,ST,和SMC(v/v)),和土壤特性(pH,EC,N,P,K,和SOC)在所有栖息地类型中重复三次。在整个栖息地,CO2,CH4和N2O通量的范围分别为125至536mgm-2h-1,0.32至28.4mgm-2h-1和0.16至3.14mgm-2h-1。生境(M3和M5)表现出比其他生境更高的GHG通量。CH4通量遵循夏季>秋季>春季>冬季的层次结构。然而,CO2和N2O通量跟随夏季>春季>秋季>冬季。CO2通量主要受ST和SOC控制。然而,CH4和N2O通量主要受生境中ST和SMC(v/v)调节。在N2O通量的情况下,土壤P和EC在整个生境中也起着至关重要的作用。AT是控制整个栖息地所有温室气体通量的通用驱动器。结果强调,亚热带喜马拉雅湿地的长期温室气体通量监测对于准确预测近期的温室气体通量及其随气候变化而变化的性质已成为当务之急。
    The study characterized the temporal and spatial variability in greenhouse gas (GHG) fluxes (CO2, CH4, and N2O) between December 2020 and November 2021 and their regulating drivers in the subtropical wetland of the Indian Himalayan foothill. Five distinct habitats (M1-sloppy surface at swamp forest, M2-plain surface at swamp forest, M3-swamp surface with small grasses, M4-marshy land with dense macrophytes, and M5-marshy land with sparse macrophytes) were studied. We conducted in situ measurements of GHG fluxes, microclimate (AT, ST, and SMC(v/v)), and soil properties (pH, EC, N, P, K, and SOC) in triplicates in all the habitat types. Across the habitats, CO2, CH4, and N2O fluxes ranged from 125 to 536 mg m-2 h-1, 0.32 to 28.4 mg m-2 h-1, and 0.16 to 3.14 mg m-2 h-1, respectively. The habitats (M3 and M5) exhibited higher GHG fluxes than the others. The CH4 flux followed the summer > autumn > spring > winter hierarchy. However, CO2 and N2O fluxes followed the summer > spring > autumn > winter. CO2 fluxes were primarily governed by ST and SOC. However, CH4 and N2O fluxes were mainly regulated by ST and SMC(v/v) across the habitats. In the case of N2O fluxes, soil P and EC also played a crucial role across the habitats. AT was a universal driver controlling all GHG fluxes across the habitats. The results emphasize that long-term GHG flux monitoring in sub-tropical Himalayan Wetlands has become imperative to accurately predict the near-future GHG fluxes and their changing nature with the ongoing climate change.
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  • 文章类型: Journal Article
    术中保持患者体温是有益的,因为低体温与围手术期并发症有关。腹腔镜手术涉及将二氧化碳(CO2)吹入腹膜腔,并且由于其与更好和更快的恢复有关,因此已成为许多手术适应症的标准。然而,使用冷和干CO2吹气可导致围手术期体温过低。我们旨在评估腹腔镜手术期间腹膜内和核心温度之间的差异,并通过拟合混合广义加性模型来评估持续时间和CO2吹入量的影响。在这项前瞻性观察性单中心队列试验中,我们纳入了年龄在17岁以上且美国麻醉学学会风险评分为I~III的腹腔镜手术患者.麻醉,通风,镇痛遵循标准协议,而患者使用毯子和温热的液体接受主动加温。温度数据,CO2通风参数,收集腹内压。我们招募了51名患者。核心温度保持在36°C以上,并随着气腹时间的流逝逐渐升高至37°C。相比之下,腹膜内温度降低,因此,从开始的0.4[25-75百分位数:0.2-0.8]°C到240分钟后的2.3[2.1-2.3]°C之间的差异越来越大。气腹持续时间和CO2吹入量显着增加了该温度差(两个参数P<0.001)。核心vs.腹膜内温差以每分钟0.01T°C的气腹时间线性增加,直至120分钟,然后每分钟0.05T°C。每单位时间内的每升吹气,即每10分钟,温度差增加了大约0.009T°C。我们的发现强调了气腹持续时间和CO2吹入量对核心温度和腹膜内温度之间差异的影响。尽管使用了干燥和未加热的CO2气体,但在腹腔镜手术期间实施充分的外部加温可有效维持核心温度。但是腹膜低温仍然是一个令人担忧的问题,这表明了进一步研究区域效应的重要性。试用注册:Clinicaltrials.gov:NCT04294758。
    Maintaining patients\' temperature during surgery is beneficial since hypothermia has been linked with perioperative complications. Laparoscopic surgery involves the insufflation of carbon dioxide (CO2) into the peritoneal cavity and has become the standard in many surgical indications since it is associated with better and faster recovery. However, the use of cold and dry CO2 insufflation can lead to perioperative hypothermia. We aimed to assess the difference between intraperitoneal and core temperatures during laparoscopic surgery and evaluate the influence of duration and CO2 insufflation volume by fitting a mixed generalized additive model. In this prospective observational single-center cohort trial, we included patients aged over 17 with American Society of Anesthesiology risk scores I to III undergoing laparoscopic surgery. Anesthesia, ventilation, and analgesia followed standard protocols, while patients received active warming using blankets and warmed fluids. Temperature data, CO2 ventilation parameters, and intraabdominal pressure were collected. We recruited 51 patients. The core temperature was maintained above 36 °C and progressively raised toward 37 °C as pneumoperitoneum time passed. In contrast, the intraperitoneal temperature decreased, thus creating a widening difference from 0.4 [25th-75th percentile: 0.2-0.8] °C at the beginning to 2.3 [2.1-2.3] °C after 240 min. Pneumoperitoneum duration and CO2 insufflation volume significantly increased this temperature difference (P < 0.001 for both parameters). Core vs. intraperitoneal temperature difference increased linearly by 0.01 T °C per minute of pneumoperitoneum time up to 120 min and then 0.05 T °C per minute. Each insufflated liter per unit of time, i.e. every 10 min, increased the temperature difference by approximately 0.009 T °C. Our findings highlight the impact of pneumoperitoneum duration and CO2 insufflation volume on the difference between core and intraperitoneal temperatures. Implementing adequate external warming during laparoscopic surgery effectively maintains core temperature despite the use of dry and unwarmed CO2 gases, but peritoneal hypothermia remains a concern, suggesting the importance of further research into regional effects.Trial registration: Clinicaltrials.gov: NCT04294758.
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  • 文章类型: Journal Article
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  • 文章类型: Journal Article
    神经血管耦合(NVC),它介导大脑血流量的快速增加,以响应神经元的激活,通常用于绘制大脑激活或功能障碍。在这里,我们测试了重新出现的假设,即神经元代谢产生的CO2有助于NVC。我们将功能性超声和双光子成像结合在小鼠桶形皮层中,以专门检查血管直径局部变化的发作。血流动力学,血管/血管周围/细胞内pH,和沿血管轴的细胞内钙信号,以响应短暂而强烈的CO2挑战(10秒,20%)和晶须刺激。我们报告说,短暂的高碳酸血症在小动脉扩张前3-4s可逆地酸化了小动脉壁和小动脉周围空间的所有细胞。在这个漫长的滞后期,由晶须刺激触发的NVC不受整个神经血管单元酸化的影响。由于它在CO2持续流入的条件下也持续存在,因此我们得出结论,NVC不涉及CO2。
    Neurovascular coupling (NVC), which mediates rapid increases in cerebral blood flow in response to neuronal activation, is commonly used to map brain activation or dysfunction. Here we tested the reemerging hypothesis that CO2 generated by neuronal metabolism contributes to NVC. We combined functional ultrasound and two-photon imaging in the mouse barrel cortex to specifically examine the onsets of local changes in vessel diameter, blood flow dynamics, vascular/perivascular/intracellular pH, and intracellular calcium signals along the vascular arbor in response to a short and strong CO2 challenge (10 s, 20%) and whisker stimulation. We report that the brief hypercapnia reversibly acidifies all cells of the arteriole wall and the periarteriolar space 3-4 s prior to the arteriole dilation. During this prolonged lag period, NVC triggered by whisker stimulation is not affected by the acidification of the entire neurovascular unit. As it also persists under condition of continuous inflow of CO2, we conclude that CO2 is not involved in NVC.
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