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581.
Pristine and trustworthy data are required for efficient computer modelling for medical decision-making, yet data in medical care is frequently missing. As a result, missing values may occur not just in training data but also in testing data that might contain a single undiagnosed episode or a participant. This study evaluates different imputation and regression procedures identified based on regressor performance and computational expense to fix the issues of missing values in both training and testing datasets. In the context of healthcare, several procedures are introduced for dealing with missing values. However, there is still a discussion concerning which imputation strategies are better in specific cases. This research proposes an ensemble imputation model that is educated to use a combination of simple mean imputation, k-nearest neighbour imputation, and iterative imputation methods, and then leverages them in a manner where the ideal imputation strategy is opted among them based on attribute correlations on missing value features. We introduce a unique Ensemble Strategy for Missing Value to analyse healthcare data with considerable missing values to identify unbiased and accurate prediction statistical modelling. The performance metrics have been generated using the eXtreme gradient boosting regressor, random forest regressor, and support vector regressor. The current study uses real-world healthcare data to conduct experiments and simulations of data with varying feature-wise missing frequencies indicating that the proposed technique surpasses standard missing value imputation approaches as well as the approach of dropping records holding missing values in terms of accuracy.  相似文献   
582.
铅暴露与健康风险研究之回顾与展望   总被引:2,自引:0,他引:2  
基于近二十年来的相关研究报道,综述了生态环境中铅的来源与命运、当前铅暴露的途径及人类健康风险等方面的最新研究动态。并指出如何在暴露的剂量一效应上进行早期诊断,进而防治因铅暴露所造成的危害,是今后铅的人类公共卫生学领域内的重要研究课题之一。  相似文献   
583.
对铬及其化合物辅助降血糖、降血脂、减肥、延缓衰老、增强免疫力等生理功能、作用机制及其在保健食品中的使用情况进行了阐述,为其在未来的保健食品中得到更好应用提供依据。  相似文献   
584.
薛宗涵  马楠  王炜罡 《化学进展》2022,34(9):2094-2107
单环芳香族硝基化合物(Nitrated mono-aromatic hydrocarbons, NMAHs)是大气中备受研究关注的一类物质,其同系物种类繁多且理化性质具有显著差异。随着研究技术的进步,外场观测能识别更丰富的NMAHs物种,实验室研究也逐渐能揭示不同NMAHs物种的生成机制。基于此,本文调研了过去近15年国内外已发表有关大气中NMAHs的文献。我们首先归纳和梳理了大气NMAHs在欧洲地区和中国地区以及其他地区的时空分布、主要来源、“气-粒”分配等特征。其次,我们结合实验室实验和外场观测结果总结了NMAHs的生成及损耗机制,并探讨了在光吸收特性、环境健康效应以及相关测量技术等方面的研究进展。最后,本文总结并提出大气NMAHs研究中仍需要解决的科学问题和未来可能的研究方向。  相似文献   
585.
为了解最近5年广州医学院港湾医院辖区内0~6岁小儿的营养、健康状况变化趋势和明确今后儿童保健工作的重点,对该院管辖的7所幼儿园集体儿童及9个居委散居儿童,连续5年(2002-2006年)的体检资料进行了回顾性分析,人数达14 485人,所有的体检资料均按照以及贫血、视力异常、龋齿的国家卫生部标准进行评价.结果表明,总体的儿童营养不良率为0.86%,肥胖率为1.87%,生长迟缓患病率为1.26%,轻度贫血率1.35%;观察各年情况,肥胖率有逐年增长趋势,儿童营养不良率无逐年下降趋势;广州医学院港湾医院辖区内0~6岁小儿的营养不良、肥胖、生长迟缓、轻度贫血等患病率低于全国水平,但也有不容忽视之处,营养不良、轻度贫血等并没有因生活水平的提高而消失.加强对家长的科学育儿健康教育,以提高他们的育儿知识水平,是儿保工作的重点,应进一步降低儿童营养不良、贫血的发生率;对儿童肥胖应当切实采取措施,预防和控制肥胖症的发生.  相似文献   
586.
The deactivation of degrading and pectinolytic enzymes is crucial in the fruit juice industry. In commercial fruit juice production, a variety of approaches are applied to inactivate degradative enzymes. One of the most extensively utilized traditional procedures for improving the general acceptability of juice is thermal heat treatment. The utilization of a non-thermal pulsed electric field (PEF) as a promising technology for retaining the fresh-like qualities of juice by efficiently inactivating enzymes and bacteria will be discussed in this review. Induced structural alteration provides for energy savings, reduced raw material waste, and the development of new products. PEF alters the α-helix conformation and changes the active site of enzymes. Furthermore, PEF-treated juices restore enzymatic activity during storage due to either partial enzyme inactivation or the presence of PEF-resistant isozymes. The increase in activity sites caused by structural changes causes the enzymes to be hyperactivated. PEF pretreatments or their combination with other nonthermal techniques improve enzyme activation. For endogenous enzyme inactivation, a clean-label hurdle technology based on PEF and mild temperature could be utilized instead of harsh heat treatments. Furthermore, by substituting or combining conventional pasteurization with PEF technology for improved preservation of both fruit and vegetable juices, PEF technology has enormous economic potential. PEF treatment has advantages not only in terms of product quality but also in terms of manufacturing. Extending the shelf life simplifies production planning and broadens the product range significantly. Supermarkets can be served from the warehouse by increasing storage stability. As storage stability improves, set-up and cleaning durations decrease, and flexibility increases, with only minor product adjustments required throughout the manufacturing process.  相似文献   
587.
(1) Background: The anthropogenically induced rise in atmospheric carbon dioxide (CO2) and associated climate change are considered a potential threat to human nutrition. Indeed, an elevated CO2 concentration was associated with significant alterations in macronutrient and micronutrient content in various dietary crops. (2) Method: In order to explore the impact of elevated CO2 on the nutritional-health properties of tomato, we used the dwarf tomato variety Micro-Tom plant model. Micro-Toms were grown in culture chambers under 400 ppm (ambient) or 900 ppm (elevated) carbon dioxide. Macronutrients, carotenoids, and mineral contents were analyzed. Biological anti-oxidant and anti-inflammatory bioactivities were assessed in vitro on activated macrophages. (3) Results: Micro-Tom exposure to 900 ppm carbon dioxide was associated with an increased carbohydrate content whereas protein, minerals, and total carotenoids content were decreased. These modifications of composition were associated with an altered bioactivity profile. Indeed, antioxidant anti-inflammatory potential were altered by 900 ppm CO2 exposure. (4) Conclusions: Taken together, our results suggest that (i) the Micro-Tom is a laboratory model of interest to study elevated CO2 effects on crops and (ii) exposure to 900 ppm CO2 led to the decrease of nutritional potential and an increase of health beneficial properties of tomatoes for human health.  相似文献   
588.
目的 为准确、快速地评价新疆地产胡桐泪中无机元素的组成及其分布特征,全面、客观、科学地评价该药材的质量,本研究采用电感耦合等离子体质谱法(Inductively Coupled Plasma-Mass Spectrometry,ICP-MS)对胡桐泪中16种无机元素进行了含量测定。方法 在采用综合评分法优化样品前处理过程的基础上,建立ICP-MS法测定胡桐泪中16种无机元素的含量并绘制其无机元素特征谱。通过热图聚类分析、主成分分析及元素间相关性分析进行化学计量学分析。通过计算样品的单项污染指数(individual pollution index ,Pi)和综合污染指数(combined pollution index ,P综)对其进行安全性评价。通过计算样品的每日最大耐受摄入量(Maximum Tolerable Daily Intake,EDI)、靶标危害系数(Target Hazard Coefficient,THQ)和致癌风险(Carcinogenic Risk,CR)等指标评估样品对人体的潜在健康风险。结果 优化后的样品前处理工艺为:盐酸-硝酸-过氧化氢-氢氟酸(3:1:1:1)体系,消解温度100℃,工艺可以满足同时测定胡桐泪中多种元素含量的需求。方法学考察结果表明本文所建立的ICP-MS方法可用于测定样品中16种元素的含量。样品的Pi与P综均处于安全水平。EDI提示对于成人和儿童而言口服胡桐泪不存在潜在健康风险。THQ和 CR结果表明样品所含的砷(As)和铅(Pb)对成年人和儿童有较高的健康风险,但无致癌风险。结论 本文建立的方法便捷准确,稳定可靠,可为胡桐泪用药安全及质量评价提供依据。  相似文献   
589.
Access to healthcare data such as electronic health records (EHR) is often restricted by laws established to protect patient privacy. These restrictions hinder the reproducibility of existing results based on private healthcare data and also limit new research. Synthetically-generated healthcare data solve this problem by preserving privacy and enabling researchers and policymakers to drive decisions and methods based on realistic data. Healthcare data can include information about multiple in- and out- patient visits of patients, making it a time-series dataset which is often influenced by protected attributes like age, gender, race etc. The COVID-19 pandemic has exacerbated health inequities, with certain subgroups experiencing poorer outcomes and less access to healthcare. To combat these inequities, synthetic data must “fairly” represent diverse minority subgroups such that the conclusions drawn on synthetic data are correct and the results can be generalized to real data. In this article, we develop two fairness metrics for synthetic data, and analyze all subgroups defined by protected attributes to analyze the bias in three published synthetic research datasets. These covariate-level disparity metrics revealed that synthetic data may not be representative at the univariate and multivariate subgroup-levels and thus, fairness should be addressed when developing data generation methods. We discuss the need for measuring fairness in synthetic healthcare data to enable the development of robust machine learning models to create more equitable synthetic healthcare datasets.  相似文献   
590.
the use of optical Fiber Bragg Grating sensors (FBG) embedded into composite laminates has proven to be an efficient way for the monitoring of the strain field inside composite laminates. The current work focuses on the use of such sensors for structural health monitoring of bonded composite repairs, often used in the aerospace as well as in the maritime industry. In such applications, the embedding location of the FBG sensors is of great importance, since apart from general strain measurements of the composite, they provide the ability of detecting whether a crack has propagated in the metal or a debonding has occurred between the metal and the composite. Within the current work, a representative case of bonded composite repair of a cracked metallic structure is examined and a series of 3D elasticity linear static finite element models are developed. Various crack lengths and patch disbond sizes have been studied while varying strain distributions were recorded along numerous paths inside the structure. Having recorded and analyzed these strain distributions, certain guidelines have been derived concerning the optimum FBG placement inside the patch, in order to ensure efficient structural health monitoring.  相似文献   
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