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Vitamin d deficiency and metabolic syndrome:The joint effect on cardiovascular and all-cause mortality in the United States adults
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作者 Longjian Liu Saishi Cui +4 位作者 Stella L Volpe Nathalie S May Deeptha Sukumar Rose Ann DiMaria-Ghalili Howard J Eisen 《World Journal of Cardiology》 2022年第7期411-426,共16页
BACKGROUND The long-term impact of vitamin D deficiency and metabolic syndrome(MetS)on cardiovascular disease(CVD)and all-cause mortality are still a matter of debate.AIM To test the hypotheses that lower serum 25 hyd... BACKGROUND The long-term impact of vitamin D deficiency and metabolic syndrome(MetS)on cardiovascular disease(CVD)and all-cause mortality are still a matter of debate.AIM To test the hypotheses that lower serum 25 hydroxyvitamin D[25(OH)D]concentrations(a marker of vitamin D level)and MetS have a long-term impact on the risk of CVD and all-cause mortality,and individuals with vitamin D deficiency can be identified by multiple factors.METHODS A sample of 9094 adults,20 to 90 years of age,who participated in the Third National Health and Nutrition Examination Survey(NHANES III,1988 to 1994)were followed through December 2015 was analyzed.The associations of serum 25(OH)D concentrations and MetS with CVD and all-cause mortality were analyzed longitudinally using Cox regression models.Classification and regression tree(CART)for machine learning was applied to classify individuals with vitamin D deficiency.RESULTS Of 9094 participants,30%had serum 25(OH)D concentrations<20 ng/mL(defined as vitamin D deficiency),39%had serum 25(OH)D concentrations between 20 to 29 ng/mL(insufficiency),and 31%had serum 25(OH)D concentrations≥30 ng/mL(sufficiency).Prevalence of MetS was 28.4%.During a mean of 18 years follow-up,vitamin D deficiency and MetS were significantly associated with increased risk of CVD and all-cause mortality.Subjects with both vitamin D deficiency and MetS had the highest risk of CVD mortality(HR=1.77,95%CI:1.22-2.58)and all-cause mortality(HR=1.62,95%CI:1.26-2.09),followed by those with both vitamin D insufficiency and MetS for CVD mortality(HR=1.59,95%CI:1.12-2.24),and all-cause mortality(HR=1.41,95%CI:1.08-1.85).Meanwhile,vitamin D sufficiency significantly decreased the risk of CVD and all-cause mortality for those who even had MetS.Among the total study sample,CART analysis suggests that being non-Hispanic Black,having lower serum folate level,and being female were the first three predictors for those with serum 25(OH)D deficiency.CONCLUSION Vitamin D deficiency and MetS were significantly associated with increased risk of CVD and allcause mortality.There was a significant joint effect of vitamin D deficiency and MetS on the risk of mortality.Findings of the CART analysis may be useful to identify individuals positioned to benefit from interventions to reduce the risk of CVD and all-cause mortality. 展开更多
关键词 joint effect Serum 25 hydroxyvitamin D concentration Metabolic syndrome Cardiovascular and all-cause mortality Cox model and machine learning
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Joint Effects of Mexidol and Nitroglycerine on Nitric Oxide Formation in Animal Liver Tissues
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作者 Taasilkan Zhumabaeva Zoya Kuropteva +4 位作者 Zhoomart Moldaliev Nazgul Zhumabaeva Amanai Kadyrbaeva Nurbek Bopoev Zhypargul Abdullaeva 《American Journal of Molecular Biology》 2021年第3期73-82,共10页
This work is investigating Mexidol (2-ethyl-6-methyl-3-hydroxy pyridine succinate) effect on the formation of nitric oxide (NO) in animal liver tissues, which is a regulator of many physiological processes and plays a... This work is investigating Mexidol (2-ethyl-6-methyl-3-hydroxy pyridine succinate) effect on the formation of nitric oxide (NO) in animal liver tissues, which is a regulator of many physiological processes and plays an important role in the vascular relaxation, neurotransmission and immune system functioning. Analyses performed by EPR spectroscopy revealed Hem-NO complex signals from paramagnetic centers in arbitrary units;produced nitrogen oxide amount in liver tissues was determined by method of double integration signals from nitrosyl complexes. 展开更多
关键词 NITROGLYCERINE Liver Tissue Nitric Oxide MEXIDOL joint effect EPR Spectra
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Joint effects of micro-sized polystyrene and chlorpyrifos on zebrafish based on multiple endpoints and gut microbial effects 被引量:2
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作者 Zhiyi Huang Xiangxiang Xiao +3 位作者 Dali Wang Yuheng Zhong Qi Ding Jing You 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第4期184-197,共14页
Microplastics often co-occur with a variety of organic contaminants in aquatic environment and pose combined risks to aquatic wildlife. Here, we investigated joint effects of microsized polystyrene(mPS, 5 μm) and an ... Microplastics often co-occur with a variety of organic contaminants in aquatic environment and pose combined risks to aquatic wildlife. Here, we investigated joint effects of microsized polystyrene(mPS, 5 μm) and an organophosphate pesticide chlorpyrifos on zebrafish,using multiple endpoints at both fish individual and gut microbiota levels. It was revealed that mPS ingested by zebrafish accumulated in gut and liver, and caused oxidative stress, hyperactive swimming performance and histological damages in fish, and induced disorders and diversity alterations of the gut microbial community. More importantly, mPS exhibited considerable adsorption capacity against chlorpyrifos, and those adsorbing chlorpyrifos presented greater effects on fish individuals but no different effects on gut microbiota compared to single mPS exposure. Together with body residues of chlorpyrifos in zebrafish,it was proposed that the joint effects between mPS and chlorpyrifos were attributed to the chlorpyrifos released from mPS within zebrafish. The present results provided a comprehensive understanding of joint effects of mPS and contaminants co-occurring in the environment and emphasized the importance of considering the adsorbed chemicals in toxicological studies of microplastics. 展开更多
关键词 Microplastics POLYSTYRENE joint effect CHLORPYRIFOS ZEBRAFISH
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Joint effects of acetochlor and urea on germinating characteristics of crop seeds
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作者 Lena Q. Ma 《Science China(Life Sciences)》 SCIE CAS 2005年第z1期1-6,共6页
In order to evaluate ecological risk of agrochemicals in common use, joint toxic effects of acetochlor and urea on germinating characteristics of Chinese cabbage (Brassica Pe-kinensis Rupr) seeds were investigated usi... In order to evaluate ecological risk of agrochemicals in common use, joint toxic effects of acetochlor and urea on germinating characteristics of Chinese cabbage (Brassica Pe-kinensis Rupr) seeds were investigated using the water-culture method and the soil-culture method. The results indicated(that excessive application of acetochlor and urea, when the concentrations were higher than 31.3 mg · kg-1 for acetochlor and 500 mg · kg-1 for urea, had strong inhibitory effects on the rate of seed germination, root elongation and hypocotyl length of Chinese cabbage. The inhibitory rate of the germinating characteristics of Chinese cabbage seeds was significantly increased with an increase in the concentration of acetochlor or urea. The two agrochemicals in water had a stronger toxicity than these in the soil at the same concentration. Among the three indexes, hypocotyl length was the most sensitive to the toxicity of acetochlor and urea. 展开更多
关键词 ecotoxicology joint effect acetochlor urea AGRICULTURAL ecosystem.
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Joint toxic effects of heavy metals and atrazine on invasive plant species Solidago Canadensis L.
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作者 HAN Zhaoxiang HE Guandong +1 位作者 WANG Jiahong LU Chunxia 《Chinese Journal Of Geochemistry》 EI CAS 2011年第4期523-530,共8页
In this study, the joint effects of Cd(Ⅱ), Pb(Ⅱ) and atrazine (ATR) on Solidago Canadensis L. were investigated. The results showed that soil containing Cd, Pb and ATR could inhibit root elongation of Solidago Canad... In this study, the joint effects of Cd(Ⅱ), Pb(Ⅱ) and atrazine (ATR) on Solidago Canadensis L. were investigated. The results showed that soil containing Cd, Pb and ATR could inhibit root elongation of Solidago Canadensis L., and that there was a positive linear relationship between the inhibitory rate of root elongation and the concentrations of Pb(Ⅱ). The mixture of Cd(Ⅱ) and Pb(Ⅱ)-ATR in soil showed a significant adverse effect on root and shoot biomass of Solidago Canadensis L. Acetylsalicylic acid (ASA) contents increased slightly at the lower concentrations of Cd(Ⅱ)-ATR, then decreased when Cd(Ⅱ)-ATR concentrations were higher than those of 1.0 TUmix(Cd+ATR). The toxic effect of Pb(Ⅱ)-ATR on the ASA contents of Solidago Canadensis L. was greater than that of Cd(Ⅱ)-ATR. Soluble sugar contents firstly decreased and then increased with increasing concentrations of Cd(Ⅱ)-ATR and displayed fluctuation with increasing concentrations of Pb(Ⅱ)-ATR. Total protein contents in-creased with increasing concentrations of Cd(Ⅱ) and Pb(Ⅱ)-ATR , relative to the control sample. The NP-SH con-tents showed a significant increase up to 12.2 mg/gfw of Cd(Ⅱ)-ATR, followed by a significant decline to 4.5 mg/gfw after 14 days of exposure. The effect of Pb(Ⅱ)-ATR was similar to that of Cd(Ⅱ)-ATR but the amount of NP-SH was not higher than that of Cd(Ⅱ)-ATR. 展开更多
关键词 加拿大一枝黄花 联合毒性作用 莠去津 入侵植物 ATR技术 重金属 地上部生物量 可溶性糖含量
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Effect of pad geometry on current density and temperature distributions in solder bump joints
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作者 李毅 赵修臣 +1 位作者 刘颖 李洪洋 《Journal of Beijing Institute of Technology》 EI CAS 2014年第2期270-278,共9页
Three-dimensional thermo-electrical finite element analyses were conducted to simulate the current density and temperature distributions in solder bump joints with different pad geometries.The effects of pad thickness... Three-dimensional thermo-electrical finite element analyses were conducted to simulate the current density and temperature distributions in solder bump joints with different pad geometries.The effects of pad thickness,diameter and shape on current density and temperate distributions were investigated respectively.It was found that pads with larger thickness or/and diameter could reduce current density and temperature in solder bump significantly.Pad shapes affected the current density and temperature distributions in solder bumps.The relatively low current density and temperature didn't occur in the bump joint with traditional rounded pad but occurred in bump joints with octagonal and nonagonal pads respectively.Therefore,optimized pad geometry may be designed to alleviate the current crowding effect and reduce the bump temperature,and therefore delay electromigration failure and increase the mean-time-to-failure. 展开更多
关键词 electromigration solder bump joint pad geometry current crowding effect current density temperature
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计及占用影响的集成楼宇暖通空调负荷群配电网优化方法
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作者 张姝 周丽萍 +2 位作者 黄河 石思晨 肖先勇 《电网技术》 EI CSCD 北大核心 2024年第11期4436-4444,I0006,I0005,共11页
提出了一种考虑人员占用影响的集成楼宇暖通空调(heating,ventilation and air conditioning,HVAC)负荷群配电电网优化方法。首先,依据建筑围护热阻热容网络和配电网支路潮流方程构建了集成暖通空调负荷群配电网数学模型。其次,利用梯... 提出了一种考虑人员占用影响的集成楼宇暖通空调(heating,ventilation and air conditioning,HVAC)负荷群配电电网优化方法。首先,依据建筑围护热阻热容网络和配电网支路潮流方程构建了集成暖通空调负荷群配电网数学模型。其次,利用梯形隶属度函数模糊化占用人数并考虑其对暖通空调负荷温度调控的影响,形成包含占用松弛函数约束的暖通空调负荷群与配电网联合优化方法。最后,通过模型预测控制方法实现了集成楼宇暖通空调负荷群配电网的滚动优化控制。改进的IEEE33节点配电网系统仿真结果表明,所提出的计及占用影响的联合优化模型,在楼宇侧能够满足人员热舒适性,同时减少楼宇暖通空调负荷能耗,在电网侧则减少配电网线路损耗和节点电压的波动,有效提高楼宇侧和电网侧整体的节能水平。 展开更多
关键词 楼宇暖通空调 配电网 联合优化 占用影响 模型预测控制
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基于零点有效缺口应力的薄板焊接接头疲劳评估
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作者 舒伟 高静坤 +3 位作者 李海峰 邓彩艳 刘强 龚宝明 《焊接学报》 EI CAS CSCD 北大核心 2024年第6期121-128,共8页
文中采用零点有效缺口应力进行了薄板焊接接头的疲劳评估研究.该方法综合考虑整体结构应力以及缺口根部到零点位置的非线性峰值应力的影响,以临界距离法和零点结构应力法为基础,将零点应力位置作为缺口对结构疲劳影响的临界距离对焊接... 文中采用零点有效缺口应力进行了薄板焊接接头的疲劳评估研究.该方法综合考虑整体结构应力以及缺口根部到零点位置的非线性峰值应力的影响,以临界距离法和零点结构应力法为基础,将零点应力位置作为缺口对结构疲劳影响的临界距离对焊接结构进行疲劳强度评估.通过对两种不同类型的焊接接头试样(T形单面焊接头和不同厚度组合搭接接头)的疲劳试验结果进行拟合.结果表明,在对焊根失效的试样进行疲劳评估时,焊根位置不同截面应力线性化之后得到零点有效缺口应力存在较大差异;其中,焊脚截面应力线性化得到的S-N曲线分散带宽度最小;再者,同时考虑焊趾和焊根失效的零点有效缺口应力S-N曲线,与分别考虑焊趾或焊根失效的零点有效缺口应力S-N曲线分散带相差不大,证明该方法可同时用于焊接接头焊趾和焊根疲劳评估. 展开更多
关键词 零点有效缺口应力 焊接接头 疲劳评估
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系统化康复治疗损伤所致膝关节疼痛及运动障碍的效果
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作者 陈薇 郭宇 《武警医学》 CAS 2024年第8期654-657,共4页
目的探讨系统化康复治疗损伤所致膝关节疼痛及运动障碍的实施效果.方法选取2022-09至2023-09在武警黑龙江总队医院康复医学与理疗科收治的损伤所致膝关节疼痛及运动障碍患者110例,根据随机数表法分为观察组和对照组,每组各55例.对照组... 目的探讨系统化康复治疗损伤所致膝关节疼痛及运动障碍的实施效果.方法选取2022-09至2023-09在武警黑龙江总队医院康复医学与理疗科收治的损伤所致膝关节疼痛及运动障碍患者110例,根据随机数表法分为观察组和对照组,每组各55例.对照组实施基础理疗和推拿的常规康复治疗,观察组实施运动疗法主导的系统化康复治疗.比较两组出现感染、延迟愈合、创伤性关节炎以及下肢静脉血栓等并发症情况,比较膝关节功能评分、疼痛评分、生理功能、心理功能、社会功能及总体健康等评分情况.结果观察组出现感染、延迟愈合、创伤性关节炎以及下肢静脉血栓等并发症的总概率低于对照组(P<0.05);治疗后观察组膝关节Lysholm评分高于对照组[(90.76±3.72)vs.(79.58±3.85),P<0.01],而VAS评分低于对照组[(2.36±0.69)vs.(5.47±1.34),P<0.01];观察组生理功能、心理功能、社会功能以及总体健康等评分高于对照组(P<0.01).结论系统化康复治疗损伤所致膝关节疼痛及运动障碍的效果显著,可以显著改善患者膝关节活动度,恢复膝关节正常功能状态. 展开更多
关键词 系统化康复 疼痛 膝关节运动障碍 实施效果
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分阶段康复治疗对肩袖损伤关节镜术后患者肩关节功能恢复的效果观察
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作者 杨丽 《中国现代药物应用》 2024年第20期161-163,共3页
目的观察分阶段康复治疗对肩袖损伤关节镜术后患者肩关节功能恢复的效果。方法70例施以关节镜手术治疗的肩袖损伤患者,以随机数字表法分成研究组和对照组,每组35例。对照组采取常规康复治疗,研究组采取分阶段康复治疗。比较两组患者治... 目的观察分阶段康复治疗对肩袖损伤关节镜术后患者肩关节功能恢复的效果。方法70例施以关节镜手术治疗的肩袖损伤患者,以随机数字表法分成研究组和对照组,每组35例。对照组采取常规康复治疗,研究组采取分阶段康复治疗。比较两组患者治疗前后肩关节功能评分及疗效。结果治疗后,两组患者疼痛、日常生活能力、肢体活动度、肌力评分及总分均较治疗前显著提升,且研究组疼痛评分(14.18±2.29)分、日常生活能力评分(15.44±2.60)分、肢体活动度评分(29.36±3.06)分、肌力评分(16.82±2.11)分及总分(75.80±6.53)分与对照组的(11.44±2.03)、(12.17±2.36)、(24.16±5.33)、(14.50±3.06)、(62.27±7.29)分相比更高,具有显著差异(P<0.05)。研究组的治疗总有效率100.00%与对照组的82.86%相比更高,具有显著差异(P<0.05)。结论对肩袖损伤关节镜术后患者实施分阶段康复治疗,可显著改善肩关节功能,提升治疗效果。 展开更多
关键词 分阶段康复治疗 肩袖损伤 关节镜术后 肩关节功能 恢复效果
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夏季气温和湿度暴露对人群非意外死亡的联合效应研究 被引量:1
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作者 方雯 林自强 +18 位作者 孟瑞琳 何冠豪 侯筑林 周脉耕 周纯良 肖义泽 俞敏 黄飙 许晓君 林立丰 肖建鹏 金东辉 秦明芳 殷鹏 许意清 胡建雄 刘涛 黄存瑞 马文军 《环境卫生学杂志》 2024年第9期736-744,共9页
目的研究夏季气温和湿度暴露对人群非意外死亡的影响。方法从中国疾病预防控制中心及广东省、浙江省、湖南省、云南省和吉林省等多省的疾病预防控制中心收集2006—2017年共124个市(自治州)的夏季人群非意外死亡时间序列资料,分别从国家... 目的研究夏季气温和湿度暴露对人群非意外死亡的影响。方法从中国疾病预防控制中心及广东省、浙江省、湖南省、云南省和吉林省等多省的疾病预防控制中心收集2006—2017年共124个市(自治州)的夏季人群非意外死亡时间序列资料,分别从国家气象科学数据中心和全国城市空气质量实时发布平台获取各研究市与死亡同期的气象数据和污染物数据。运用分布滞后非线性模型(distributed lag non-linear model,DLNM)分别拟合气温、湿度与人群死亡风险的暴露反应关系。运用分位数g计算回归(quantile g-computation,qgcomp)模型评估气温和湿度复合暴露对人群非意外死亡的联合效应。结果夏季气温与人群死亡风险的累计死亡效应呈“J”型,而湿度与死亡之间的暴露-反应关系则呈倒“J”型。气温和湿度复合暴露与人群非意外死亡风险的关联呈非线性关系,以复合暴露的第一分位数作为参考,第二、三、四分位数对应的相对危险度(relative risk,RR)分别是1.01(95%CI:1.00~1.02)、1.04(95%CI:1.02~1.05)和1.08(95%CI:1.05~1.10),其中男性、≥65岁人群以及脑血管疾病患者是敏感人群,中部地区人群危险性较低。气温和湿度在全人群联合效应中的贡献分别为84.92%和15.08%,男性与≥65岁人群的气温效应占比大于同亚组人群,分别为86.98%和86.16%,北方、中部和南方地区气温效应占比均在80%左右。心血管疾病、脑血管疾病和呼吸系统疾病气温效应占比分别为68.01%、72.44%和71.46%。结论在夏季随着气温和湿度均升高,人群的非意外死亡风险增加,气温在联合效应中的贡献占比较高。性别、年龄、地区和患病情况均对气温和湿度的联合死亡效应有修饰作用。 展开更多
关键词 气温 湿度 联合效应 非意外死亡
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长三角地区联合河长制政策效果模拟与仿真研究
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作者 黄万华 冯燕 +1 位作者 高红贵 黄轲 《生态经济》 北大核心 2024年第9期187-198,共12页
基于DPSIR理论,运用系统动力学的方法,构建长三角地区联合河长制政策仿真模型,从水资源保护、水污染防治、水生态修复、水环境治理等维度,通过模拟与仿真,纵横对比联合河长制的政策效果,分析联合河长制政策2023—2035年的政策效果。研... 基于DPSIR理论,运用系统动力学的方法,构建长三角地区联合河长制政策仿真模型,从水资源保护、水污染防治、水生态修复、水环境治理等维度,通过模拟与仿真,纵横对比联合河长制的政策效果,分析联合河长制政策2023—2035年的政策效果。研究结果表明:(1)长三角地区联合河长制政策整体效果比较显著,在水资源保护、水污染防治、水生态修复、水环境治理四个方面的政策效果明显;(2)自2023年起的未来十多年,联合河长制政策效果呈减弱趋势,并不具有较强的可持续性,要持续实现联合河长制较好的政策效果,需要进一步深化完善与联合河长制政策相配套的协作机制、动力机制、保障机制、监督机制等政策体系。论文为解决长三角地区流域治理中上下游,干支流、左右岸不协同,优化流域单元与行政单元间的“条”“块”协同机制,推进长三角地区协同大保护与高质量发展具有十分重要的理论意义和实践价值。 展开更多
关键词 系统动力学 联合河长制 政策效果 仿真模拟 长三角地区
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经穴位至关节突注射臭氧水配合推拿、针刺对关节突源性腰痛的影响 被引量:1
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作者 宋如意 张丽 +1 位作者 孙飞 杨勇 《中医药信息》 2024年第7期56-60,共5页
目的:观察经穴位至关节突注射臭氧水配合推拿、针刺治疗关节突源性腰痛的临床效果。方法:前瞻性选取河南中医药大学第三附属医院收治的符合纳入标准的106例关节突源性腰痛患者为研究对象,依据随机数字表随机分为研究组53例和对照组53例... 目的:观察经穴位至关节突注射臭氧水配合推拿、针刺治疗关节突源性腰痛的临床效果。方法:前瞻性选取河南中医药大学第三附属医院收治的符合纳入标准的106例关节突源性腰痛患者为研究对象,依据随机数字表随机分为研究组53例和对照组53例。对照组接受推拿、针刺治疗,研究组接受经穴位至关节突注射臭氧水配合推拿、针刺治疗,均治疗3个疗程。比较两组疗效、不良反应与复发率,以及治疗不同时间点疼痛程度(VAS评分)、腰椎功能障碍评分(ODI评分)和生活质量评价量表评分(SF-36评分)差异。结果:治疗后,两组临床疗效比较差异有统计学意义(Z=2.572,P<0.05),研究组总优良率88.68%(47/53)高于对照组71.7%(38/53),复发率7.55%(4/53)低于对照组22.64%(12/53)(P<0.05)。两组VAS评分和ODI评分的时点效应、组间效应、交互效应比较,差异有统计学意义(P<0.05),两组治疗1个疗程后、治疗3个疗程后VAS评分和ODI评分均低于治疗前(P<0.05),且研究组治疗1个疗程后、治疗3个疗程后VAS评分和ODI评分均低于对照组(P<0.01)。治疗期间两组患者不良反应发生率比较,差异无统计学意义(P>0.05)。两组治疗后生活质量评价量表(SF-36)各维度得分(躯体疼痛、社会功能、精神健康、生理职能、情感职能、生理功能、精力)均高于治疗前(P<0.05),且研究组治疗3个疗程后SF-36量表各项得分均高于对照组(P<0.05)。结论:经穴位至关节突注射臭氧水配合推拿、针刺治疗关节突源性腰痛具有较好临床疗效,可有效降低复发率,改善疼痛程度与腰椎功能障碍,提高生活质量,且安全性较好。 展开更多
关键词 关节突源性腰痛 穴位至关节突注射臭氧水 推拿 针刺 临床效果
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Effective way of alleviating poverty against poverty control: Based on the model of "Three Drives, Four Joints" in Zhen'an County
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作者 HE De-gui ZHONG Xiao-rong 《Ecological Economy》 2017年第2期150-164,共15页
Based on the survey research of poverty controlling model of "Three Drives, Four Joints" in Zhen'an County, its forming motives, implementing mechanism, and constraint factors have been explored to testi... Based on the survey research of poverty controlling model of "Three Drives, Four Joints" in Zhen'an County, its forming motives, implementing mechanism, and constraint factors have been explored to testify its enlightenment and applicability, establishing a promotable, applicable, and effective poverty alleviation model. "Three Drives, Four Joints" model is linked to the poor who lacks ability of self-development. Relying on the drives from key leading companies, the capable and the rich, a community with shared interests by the poor and the subjects of the "three drives" could be formed through "Joint Production, Joint Resources, Joint Community of Stock, and Joint Operation". The linked poverty alleviation development model of "the influential and the rich bring along the poor" and "A rich household would help the others" come into being. It is found out that the model of "Three Drives, Four Joints" is in essence a poverty alleviation method focusing on the increase of the income and diversified ways of increasing the earnings. Problems of poverty alleviation carrier and joint mechanism have been solved in the poverty alleviation process. The model is innovative in activating the resource elements, helping to move the poor out of poverty. A referential, copyable, and applicable model is offered to advance the poverty alleviation in mountainous areas in China. 展开更多
关键词 poverty control poverty alleviation effective way model of "Three Drives Four joints"
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无人机数据链射频前端高强辐射场干扰效应研究
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作者 马振洋 李慕凡 李斌 《中国民航大学学报》 CAS 2024年第5期14-21,共8页
针对四旋翼无人机(UAV,unmanned aerial vehicle)数据链在低空飞行时易受高强辐射场(HIRF,high intensity radiated field)干扰的问题,本文采用场-路联合仿真的方法对其进行干扰效应的研究。首先,利用电磁仿真软件探究UAV整机模型在HIR... 针对四旋翼无人机(UAV,unmanned aerial vehicle)数据链在低空飞行时易受高强辐射场(HIRF,high intensity radiated field)干扰的问题,本文采用场-路联合仿真的方法对其进行干扰效应的研究。首先,利用电磁仿真软件探究UAV整机模型在HIRF下的天线耦合效应,并对不同辐照方向、信号类型和脉宽系数下的耦合电压进行分析;其次,通过电路设计分析软件对数据链射频(RF,radio frequency)前端电路进行注入仿真并分析干扰效应。结果表明,脉宽系数越小,高斯脉冲造成的干扰越强,相同脉宽系数下的调制高斯脉冲造成的干扰强于高斯脉冲;干扰信号的加入会导致射频前端中频(IF,intermediate frequency)输出信号的峰值显著增大,峰值频率发生偏移以及信噪比降低。 展开更多
关键词 高强辐射场(HIRF) 无人机数据链 场-路联合仿真 干扰效应
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浅埋黄土地层隧道在不同交角下穿既有地下管线的模型试验
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作者 苏永华 李明 《安全与环境学报》 CAS CSCD 北大核心 2024年第5期1786-1794,共9页
为探究浅埋黄土地层盾构隧道施工下穿对不同特性地下管线的变形受力影响机制,依托河南省某公路隧道工程,以工程黄土为试验材料进行室内模型试验。通过设置3种管隧交角,研究两种接头刚度的非连续管线和连续管线的沉降、弯矩和管土接触压... 为探究浅埋黄土地层盾构隧道施工下穿对不同特性地下管线的变形受力影响机制,依托河南省某公路隧道工程,以工程黄土为试验材料进行室内模型试验。通过设置3种管隧交角,研究两种接头刚度的非连续管线和连续管线的沉降、弯矩和管土接触压力变化规律,并在管隧正交工况下,研究不同地下管线的遮拦效应及地表沉降变形规律,得出预测管线沉降的拟合公式。结果表明:在3种管隧交角下,地下管线沉降存在3个阶段,在管线沉降集中区阶段低密度聚乙烯(Low Density Polyethylene,LDPE)接头非连续管线的平均沉降增长速率是聚氯乙烯(Polyvinyl Chloride,PVC)接头非连续管线的2倍;管隧交角的减小,使得非连续管线的最大正负弯矩均减小,PVC接头非连续管线弯矩曲线由“W”形转变为“V”形;管隧交角和接头刚度对土压力变化曲线和峰值位置几乎无影响,土压力变化均呈“M”形;在管隧正交下,管线整体刚度越大对地表沉降抑制作用越显著,管线沉降与地表沉降呈指数关系。 展开更多
关键词 安全工程 接头刚度 非连续管线 地表沉降 遮拦效应
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老年股骨颈骨折围手术期精准护理干预效果观察 被引量:2
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作者 何莹莹 陈进芬 +4 位作者 张小丽 景作磊 李桂焕 蔡琼珠 张斌 《现代医院》 2024年第2期325-328,共4页
目的探讨手术治疗老年股骨颈骨折患者过程中采取精准护理方案的效果及应用意义。方法选择2022年5月—2023年5月因老年股骨颈骨折入院治疗的颈中型骨折、头下型骨折、基底型骨折患者共70例为对象,根据患者入院顺序随机分为对照组与观察组... 目的探讨手术治疗老年股骨颈骨折患者过程中采取精准护理方案的效果及应用意义。方法选择2022年5月—2023年5月因老年股骨颈骨折入院治疗的颈中型骨折、头下型骨折、基底型骨折患者共70例为对象,根据患者入院顺序随机分为对照组与观察组各35例,均行手术方案,围手术期,对照组实施常规护理干预,观察组实施精准护理干预,比较两组患者的心理状态、并发症情况、髋关节功能恢复情况及预后。结果护理干预后,两组心理状况评分均较干预前低(P<0.05),且观察组心理状态评估得分较对照组低,心理状态更好(P<0.05);观察组术后发生并发症例数明显较对照组例数少(P<0.05);观察组髋关节功能恢复程度评分较对照组评分高(P<0.05);两组出院3个月时的生活自理能力评分均高于出院时,股骨头坏死评分低于出院时,且观察组生活自理能力评分较对照组评分高,股骨头坏死评分低于对照组,即观察组预后优于对照组(均P<0.05)。结论实施精准护理干预对改善老年股骨颈骨折患者预后、提高老年患者生活自理能力有积极影响。 展开更多
关键词 髋关节功能 预后效果 股骨颈骨折 手术 精准护理干预
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多变量联合模型在隧道通风系统寿命预测中的应用研究
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作者 雷崇 冯腾 +5 位作者 夏继豪 钱新博 孙言俊 姜学鹏 李科 严斌 《安全与环境学报》 CAS CSCD 北大核心 2024年第10期3854-3861,共8页
为了提高隧道通风系统的智能运维水平,将基于数据驱动的联合模型引入隧道通风系统进行剩余使用寿命(Remaining Useful Life,RUL)预测,即综合失效事件和状态监测数据进行RUL动态预测。针对基于失效事件和状态监测数据融合的RUL预测,目前... 为了提高隧道通风系统的智能运维水平,将基于数据驱动的联合模型引入隧道通风系统进行剩余使用寿命(Remaining Useful Life,RUL)预测,即综合失效事件和状态监测数据进行RUL动态预测。针对基于失效事件和状态监测数据融合的RUL预测,目前工业领域主要使用两阶段模型法,该方法遵循“先退化建模,后失效建模”的步骤。由于隧道通风系统受到地铁工况环境的影响,退化过程和失效事件存在相互影响,提出了基于多元变量的联合模型,旨在辨识共享随机效应,进而降低退化模型和失效模型估计偏差,提高隧道通风系统RUL动态预测的准确度。基于调研发现,地铁隧道通风系统主要故障模式为风机轴承磨损,研究主要通过风机轴承磨损失效仿真算例,选用平均绝对误差比较所提出的方法与两阶段法、单元联合模型的预测性能。算例研究结果表明,多元联合模型方法能有效辨识出监测状态演变和失效事件的关联关系,降低模型估计的偏差,为地铁隧道安全运行提供决策支持。 展开更多
关键词 安全工程 隧道通风系统 联合模型 退化模型 失效模型 随机效应
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Single and joint stress of acetochlor and Pb on three agricultural crops in northeast China 被引量:14
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作者 CHAO Lei ZHOU Qi-xing +2 位作者 CHEN SU CUI Shuang WANG Mei-e 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第6期719-724,共6页
In order to evaluate ecological risk of agrochemicals in agricultural environment, single and joint toxic effects of an important herbicide and a typical heavy metal on root elongation of crops were investigated. Seed... In order to evaluate ecological risk of agrochemicals in agricultural environment, single and joint toxic effects of an important herbicide and a typical heavy metal on root elongation of crops were investigated. Seeds of the three crops including wheat (Triticum aestivum), Chinese cabbage (Brassica pekimensis) and soybean (Glycine max) as the main crops in northeast China were exposed to acetochior as a herbicide and lead (Pb) as a heavy metal using the pot-culture method, and meadow brown soil as one of the main soils distributed in northeast China was applied in the investigation. The results indicated that the interactive effects of the two pollutants on root elongation of the three crops were very complicated although they had markedly significant (P〈0.01) linear interrelationships based on the regression analyses. When the concentration of added Pb^2+ reached 200 mg/kg, acetochlor and Pb had an antagonistic effect on the inhibition of root elongation of the three crops. However, acetochlor and Pb had significantly (P〈0.05) synergic effects on the inhibition of root elongation when concentration of added Pb^2+ was up to 1000 mg/kg. At the low concentration of added Pb, joint toxicity of acetochlor and Pb was more dependent on the concentration of Pb. Among the three crops, wheat was the most sensitive to the toxicity of Pb and Chinese cabbage was the most sensitive to the toxicity of acetochlor. 展开更多
关键词 ACETOCHLOR PB ECOTOXICOLOGY joint effect Chinese cabbage (Brassica pekimensis) soybean (Glycine max) wheat (Triticum aestivum)
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玄武岩节理系数及其与强度和变形特性的关系研究
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作者 孔洋 阮怀宁 +2 位作者 张桂荣 何宁 汪璋淳 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第S01期132-137,共6页
节理密度、节理倾角与节理粗糙度情况等是控制玄武岩力学响应的三个关键因素。基于3D打印技术,通过开展单轴压缩与界面剪切试验,针对不同的模拟柱状节理玄武岩试样的破坏模式深入探究了特殊柱状节理的存在对玄武岩强度与变形的弱化作用... 节理密度、节理倾角与节理粗糙度情况等是控制玄武岩力学响应的三个关键因素。基于3D打印技术,通过开展单轴压缩与界面剪切试验,针对不同的模拟柱状节理玄武岩试样的破坏模式深入探究了特殊柱状节理的存在对玄武岩强度与变形的弱化作用,分析了节理系数与试样各向异性效应的关系。研究结果表明随节理系数的增大,模拟柱状节理玄武岩试样强度折减系数的线性减小程度及模量折减系数以指数关系式降低幅度受失效模式影响显著;强度各向异性效应与模量各向异性效应数值越大,表明柱状节理对玄武岩的岩块弱化作用越强;不同失效模式工况下,随节理系数的增加,强度各向异性效应线性增大,模量各向异性效应以指数关系式升高。研究成果可为工程岩体各向异性力学响应分析提供一定的技术支撑。 展开更多
关键词 玄武岩 节理系数 弱化效应 强度 变形 各向异性
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