Study of Mechanical Properties and Durability of Alkali-Activated Coal Gangue-Slag Concrete

Herein, a new geopolymer is recognized as a potential alternative cementing material of ordinary Portland cement (OPC), which is used for reducing carbon emissions and efficiently recycling the waste. Therefore this paper mainly studied the alkali-activated coal gangue-slag concrete (ACSC) was prepared by using the coal gangue-slag and Na₂SiO₃ and NaOH complex activator. The ratio of coal gangue (calcined and uncalcined) coarse aggregate replacing the gravel was 0%, 30%, 50%, 70%, and 100%. The water and salt freeze-thaw resistance, compressive strength, chloride permeation, microstructure, performance mechanism, inner freeze-thaw damage distribution, and mechanics models of ACSC were investigated. Results show that ACSC displayed excellent early age compressive strength, and the compact degree and uniformity of structure were better compared with the ordinary Portland cement (OPC) when the coal gangue replacement rate was less than 50%. The ACSC demonstrated the best chloride penetration resistance under 30% uncalcined coal gangue content, which was less than 27.75% lower than that of using OPC. At the same number cycles, especially in the salt freezing, the calcined coal gangue had lowered advantages of improving resistance freeze-thaw damage resistance. Water and salt accumulative freeze-thaw damage mechanics models of ACSC were established by using the relative dynamic elasticity modulus. The exponential function model was superior to the power function model with better precision and relativity, and the models accurately reflected the freeze-thaw damage effect.     

In vitro and in vivo evaluation of porous PCL-PLLA 3D polymer scaffolds fabricated via salt leaching method for bone tissue engineering applications

Three dimensional porous scaffolds composed of various ratios of polycaprolactone and poly(L-lactic acid) (PLLA) were prepared using salt leaching method for bone regeneration applications. Surfaces of the scaffolds were visualized using scanning electron microscope (SEM) and the combination of the polymers was confirmed by FT-IR. Addition of PLLA increased the porosity and pore sizes of the scaffolds and also the scaffolds’ compressive strength initially. Osteoblast-like cells were used and it was found that the samples’ cell biocompatibility was further promoted with the increase in PLLA content as observed via cell proliferation assays using MTT, gene expression with RT-PCR, and micrographs from SEM and confocal microscopy. Samples were then implanted into male rabbits for 2 months, and histological staining and micro-CT histomorphometry show that new bone formations were detected in the site containing the implants of the scaffolds and that bone regeneration was further promoted with the increased concentration of PLLA in the scaffold.     

Drinking frequency modifies an association between salt intake and blood pressure: A cohort study

Salt sensitivity is one of the crucial risk factors of hypertension. The aim of the present prospective cohort study was to assess the clinical impact of alcohol drinking on an association between salt intake and blood pressure. The present study included 451 employees at a pharmaceutical company in Japan who underwent annual health checkups in both 2017 and 2018. The main exposure of interest was self‐reported drinking frequency at their first checkups: rarely, occasionally, and daily. To assess the association between the change of salt intake estimated from single‐spot urine specimens and that of blood pressure, the differences in systolic/diastolic blood pressure and salt intake between 2017 and 2018 were calculated for each subject. Multivariable‐adjusted linear regression models adjusting for clinically relevant factors clarified a drinking frequency‐dependent association between Δsalt intake and Δsystolic blood pressure (per 1 g/d of Δsalt intake adjusted β [95% confidence interval] 0.19 [−0.73, 1.12], 0.84 [0.14, 1.53], and 1.78 [0.86, 2.69] in rare, occasional, and daily drinkers). A similar association between Δsalt intake and Δdiastolic blood pressure was also observed (−0.24 [−1.02, 0.54], 0.67 (0.18, 1.16), 0.95 [0.38, 1.51], in rare, occasional, and daily drinkers). The interactions between drinking frequency and Δsalt intake were found to be statistically significant (P for interaction = .028 and .006 for ∆systolic blood pressure and ∆diastolic blood pressure, respectively). The present study identified enhanced salt sensitivity in the subjects who drink at a higher frequency, suggesting that the reduction in alcohol consumption may improve salt sensitivity in higher frequency drinkers.     

Effects of salt intervention on serum levels of Klotho influenced by salt sensitivity

Klotho was involved in sodium reabsorption and the regulation of blood pressure. Animal studies indicated Klotho deficiency could mediate the development of salt‐sensitive hypertension, indicating its correlation with salt sensitivity. We aimed to explore the responses of Klotho to salt intake through dietary intervention in Chinese adults. Forty‐four participants were enrolled from Lantian county of Shaanxi, China. All participants sequentially underwent a 3‐day normal diet, a 7‐day low‐Na⁺ diet, and a 7‐day high‐Na⁺ diet. The concentrations of serum Klotho were assessed by using ELISA kits. Serum level of Klotho was 360.44 ± 93.89 pg/mL at baseline and increased while changed to low‐salt diet (478.65 ± 183.25 vs 360.44 ± 93.89 pg/mL, P < .001). During high‐salt diet, serum Klotho decreased to 354.37 ± 98.16 pg/mL (P < .001, compared to low‐salt diet). The overall responses of Klotho were more prominent in salt‐resistant participants. Serum Klotho of salt‐resistant group changed from 353.92 ± 97.65 pg/mL to 496.76 ± 196.21 pg/mL while changed from normal diet to low‐salt diet (P < .001) and decreased to 350.37 ± 99.50 pg/mL during high‐salt intake (P < .001). Furthermore, the response of serum Klotho to low‐salt intervention was much greater in salt‐resistant individuals than in salt‐sensitive ones. The responses of serum Klotho to dietary salt intervention were influenced by salt sensitivity, which was more prominent in salt‐resistant participants.     

2009 - 2013 年自流井区居民食用碘盐监测结果分析

目的及时掌握四川省自贡市自流井区居民户碘盐普及情况,评价碘盐措施落实情况,为适时采取针对性防治措施和科学调整干预策略提供依据。方法按照《四川省碘盐监测方案》的求,每年抽取9个乡镇（街道）的36个行政村（居委会）开展居民户碘盐常规监测工作。结果自贡市自流井区2009—2013年共监测1464份居民食用盐样,其中检测出非碘盐33份、不合格碘盐53份、合格碘盐1378份,碘盐覆盖率、碘盐合格率、合格碘盐食用率分别为97．8％、96．3％、94．1％。结论自贡市自流井区居民食用加碘盐总体情况良好,消除碘缺乏病的目标得到持续巩固。     

丹阳市不同环境药物灭螺效果

目的 目的 评价在有螺江滩、 河道、 渠道连续使用氯硝柳胺乙醇胺盐后的灭螺效果。方法 方法 选择丹阳市后巷镇北魏 江滩、 陵口镇肖梁河、 云阳镇老庙渠道作为研究现场, 采用4%氯硝柳胺乙醇胺盐粉剂50 g/m2 和26%四聚杀螺胺 （2～4） g/m2 实施灭螺。综合利用历史资料和现场调查资料, 评价连续应用灭螺药物后的效果。结果 结果 至2013年, 北魏江滩、 肖梁河、 老庙渠道钉螺面积较首次复现时分别下降了82.80%、 63.14%和70.00%, 钉螺面积与钉螺密度均呈显著正相关 （r = 0.931、 0.975、 0.916, P均＜0.05）; 灭螺后活螺平均密度较首次复现时下降了92.34%、 87.91%和97.66%。灭螺后钉螺校正死亡率 与次年活螺平均密度均呈负相关（r = -0.998、 -0.999、 -0.970）; 活螺密度下降率与次年活螺平均密度均呈负相关 （r = -0.997、 -0.998、 -0.868）。结论 结论 药物灭螺在压缩钉螺面积、 降低钉螺密度、 控制血吸虫病传播等方面效果明显。     

三种新型可聚合抗菌单体对口腔病原菌的抗菌活性研究

目的:比较自行合成的3种可聚合季铵盐抗菌单体DMAE-MMA salt,DMAEMA-MMA salt,DMAEMA-PMDPM salt对口腔常见致病菌的抗菌活性。方法:采用液体稀释法测定季铵盐单体对4种口腔常见致病菌的抗菌活性,以抗菌性能最佳的单体进行杀菌动力学研究。结果:3种季铵盐单体对4种口腔致病菌均表现出一定的抗菌活性,其中DMAEMA-PMDPM salt抗菌效果较其它2种好,该单体在浓度为78.8 mg/ml即4倍MBC浓度时,白色念珠菌与其接触120 min时可达到灭菌效果。结论:这3种季铵盐单体对常见口腔致病菌均表现出一定的抗菌活性。