Ternary Blends for Self-Compacting Mortars Production Composed by Electric Arc Furnace Dust and Other Industrial by-Products

This study is framed within the circular economy model through the valorisation of industrial by-products. This research shows the results of producing self-compacting mortars (SCMs) with electric arc furnace dust (EAFD) and other industrial by-products such as fly ash, conforming (FA) or not conforming (NcFA), from coal-fired power plants, or recovery filler (RF) from hot-mix asphalt plants. Three batches of SCMs, each with one industrial-by product (FA, NcFA, or RF), and three levels of EAFD ratio incorporation (0%, 10%, 20%), were tested. An extra batch with a greater amount of FA was manufactured. When the incorporation ratio of EAFD rose, the mechanical strength decreased, due to the presence of a calcium zinc hydroxide dihydrate phase; nevertheless, this decrease diminished over time. All SCM mixes, except the 40C 40FA 20 EAFD mix, were above 20 MPa at 28 days. All mixes named 70C and 40C reached 40 and 30 MPa, respectively, at 90 days. Mixes with EAFD showed less capillarity and no difference in water absorption by immersion with respect to mixes without EAFD after 91 days. The SCMs designed proved to be stable in terms of leaching of the heavy metals contained in EAFD, where all the hardened SCMs were classified as inert.     

儿童无创通气的局限性及气管插管介入时机选择

近年来,无创通气在儿童呼吸支持领域有了较快发展。无创通气无需气管插管,操作简便,对部分呼吸道疾病有较为满意的疗效。但是,无创通气不能完全替代有创机械通气。在有些疾病无创通气不仅有着较高的失败率,而且会因气管插管的延误导致病情恶化,增加患儿的病死率。在行无创通气之前需评估患儿是否适宜进行无创通气治疗。对于进行无创通气治疗的患儿需严密监护,动态观察生理指标和监测数据的变化,掌握好气管插管的时机,以免造成有创机械通气治疗的延误。     

The comparison of effects of processed Aconiti tuber, U50488H and MK-801 on the antinociceptive tolerance to morphine

In the previous studies, we demonstrated that an oriental herbal medicine, processed Aconiti tuber (PAT), at subanalgesic doses could inhibit or reverse the antinociceptive tolerance to morphine. In the present study, we compared the effect of PAT, trans-(+/-)-3,4-dichloro-N-methyl-N-(2-(1-pyrrolidin)cyclohexyl)-benzeneacetamide methane sulfonate hydrate (U50488H), a selective kappa opioid receptor (KOR) agonist, and (-)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine-maleate (MK-801), a N-methyl-D-aspartate (NMDA) receptor antagonist, on the antinociceptive tolerance to morphine in the same experimental condition. Mice received subcutaneous morphine (10 mg/kg), and oral PAT at a subanalgesic dose (0.3 g/kg for mechanical or 1.0 g/kg for thermal test), or intraperitoneal U50488H at a subanalgesic dose (3 mg/kg), or MK-801 at a subanalgesic dose (0.1 mg/kg) once daily for 14 days. The mechanical nociceptive threshold was measured before, and at 60 min by tail pressure testing, and thermal nociceptive latency was measured before, and at 30 min by hot plate testing, after daily morphine injections. PAT and U50488H could not only inhibit the development of morphine tolerance but also reverse the already-developed morphine tolerance, while MK-801 could only inhibit the development of morphine tolerance but not reverse the already-developed morphine tolerance, in both mechanical and thermal nociceptive tests. These data suggested that PAT, an indirect-acting KOR agonist, share the common pharmacological property of KOR agonists on morphine tolerance, and that PAT may be superior to some NMDA receptor antagonists which do not reverse already-developed morphine tolerance.     

Do ventilated neonates require pain management?

Mechanical ventilation is a stressful experience in neonates resulting in changes in neuroendocrine parameters, pain scores, and physiologic responses. Assisted ventilation in neonates is presumed to be associated with chronic repetitive pain, which in turn is associated with adverse long-term sequelae. Reasons to routinely sedate ventilated neonates include improved ventilator synchrony, improved pulmonary function, and decreased neuroendocrine responses, including cortisol, beta-endorphine, and catecholamines. Reasons not to treat include the well-known adverse side effects of pain medication, especially the opiates, including hypotension from morphine, chest wall rigidity from fentanyl, and tolerance, dependence, and withdrawal from both opiates and benzodiazepines. Additionally, adverse effects such as death and IVH are not improved with preemptive treatment. Chronic pain assessment is poorly validated and difficult to assess in this population, and most studies have evaluated only acute pain scores. If patients are treated, opiates are the most common class of drugs, with morphine the most well studied. Fentanyl may be advantageous in hypotensive, younger neonates because it has fewer cardiovascular effects. The benzodiazepines, midazolam and lorazepam, have been used in ventilated neonates, but midazolam has been associated with adverse effects in one small study so concern remains regarding its use. Significant gaps in our knowledge exist, especially in regard to long-term effects of treatment, or lack thereof, and in the assessment of the chronic pain associated with assisted ventilation.     

吸入一氧化氮技术治疗新生儿严重低氧血症的疗效分析

目的:探讨吸入一氧化氮(iNO)治疗新生儿严重低氧血症的临床疗效.方法:38例重症呼吸衰竭新生儿,平均胎龄(34±6)周,体重(2 187±181)g,因在常频通气(CMV)治疗过程中出现FiO2≥0.8,平均气道压≥0.98 kPa,持续2 h以上经皮氧饱和度≤90%或氧合指数(OI)＞40而采用iNO,治疗过程中监...     

材料力学性能对人颞下颌关节力三维非线性模拟的影响

比较分析骨性结构和关节盘的材料力学性能对在活性基础上建立的人颞下颌关节（Ｔｅｍｐｏｒｏ－ｍａｎｄｉｂｕｌａｒｊｏｉｎｔ,ＴＭＪ）三维非线性有限元模型模拟ＴＭＪ力的影响。方法利用Ａｕｔｏ－ＣＡＤ软件及螺旋ＣＴ扫描技术与有限元应力分析方法的相结合在活性基础上建立ＴＭＪ三维非线性有元模拟型并比较下颌骨,关节窝和关节盘选用不同材料力学性能时关节内应力的变化。结果骨组织的各种向同性和各向异性特征使组成ＴＭＪ     

高龄重度急性左心衰竭并呼吸衰竭患者的机械通气治疗

目的　总结在高龄重度急性左心衰竭（ALVF）合并急性呼吸衰竭（ARF）患者应用机械通气治疗的临床经验。方法　回顾性总结10年间102例高龄重度ALVF并ARF患者应用机械通气治疗的方式、好转率、病死率和合并症,并将合并Ⅰ型ARF（ARF-Ⅰ）（42例）和Ⅱ型ARF（ARF-Ⅱ）（60例）两组患者资料进行比较。结果　102例115次机械通气途径经鼻面罩给氧18次,经鼻插管68次,经口插管29次;通气方式容量控制115次,压力控制25次,稳定气道正压(CPAP)26次,呼气终末加压(PEEP)45次。病情好转率在全部病人、ARF-Ⅰ和ARF-Ⅱ组分别是60.8%,69.0%和55.0%（两组比较P<0.05）;病死率分别是39.2%,30.9%,45.0%（两组比较P<0.05）。用呼吸机过程中的主要合并症在全部病人为心律失常37.3%,低血压35.3%,肺感染34.3%,消化道出血31.4%,酸碱失衡20.6%,张力性气胸2.9%。两组比较显示ARF-Ⅱ组病情重,病死率高,合并症多。结论　高龄重度ALVF并ARF患者机械通气治疗难度大,风险高,但只要严格掌握适应征及合适的通气方式,注意防治合并症,仍可以取得良好疗效,挽救大部分患者的生命。     

脑电双频指数在不同年龄段机械通气病人中的应用价值

目的研究脑电双频指数(BIS)在不同年龄段应用咪达唑仑镇静的机械通气病人中的应用价值。方法前瞻性选取60例需应用咪达唑仑镇静8 h以上的机械通气病人,按不同年龄段分成3组,常规应用Ramsay评分镇静管理,在不同时段应用BIS检测镇静深度,比较镇静过度及不足发生率。结果 40～60岁组容易发生镇静不足,60岁以上组最容易发生镇静过度。结论在ICU机械通气病人的镇静治疗中,60岁以上者应用BIS指导更有价值。     

Agar Biopolymer Films for Biodegradable Packaging: A Reference Dataset for Exploring the Limits of Mechanical Performance

This article focuses on agar biopolymer films that offer promise for developing biodegradable packaging, an important solution for reducing plastics pollution. At present there is a lack of data on the mechanical performance of agar biopolymer films using a simple plasticizer. This study takes a Design of Experiments approach to analyze how agar-glycerin biopolymer films perform across a range of ingredients concentrations in terms of their strength, elasticity, and ductility. Our results demonstrate that by systematically varying the quantity of agar and glycerin, tensile properties can be achieved that are comparable to agar-based materials with more complex formulations. Not only does our study significantly broaden the amount of data available on the range of mechanical performance that can be achieved with simple agar biopolymer films, but the data can also be used to guide further optimization efforts that start with a basic formulation that performs well on certain property dimensions. We also find that select formulations have similar tensile properties to thermoplastic starch (TPS), acrylonitrile butadiene styrene (ABS), and polypropylene (PP), indicating potential suitability for select packaging applications. We use our experimental dataset to train a neural network regression model that predicts the Young’s modulus, ultimate tensile strength, and elongation at break of agar biopolymer films given their composition. Our findings support the development of further data-driven design and fabrication workflows.     

Influence of Test Specimen Geometry on Probability of Failure of Composites Based on Weibull Weakest Link Theory

This paper presents an analytical model that quantifies the stress ratio between two test specimens for the same probability of failure based on the Weibull weakest link theory. The model takes into account the test specimen geometry, i.e., its shape and volume, and the related non-constant stress state along the specimen. The proposed model is a valuable tool for quantifying the effect of a change of specimen geometry on the probability of failure. This is essential to distinguish size scaling from the actual improvement in measured strength when specimen geometry is optimized, aiming for failure in the gauge section. For unidirectional carbon fibre composites with Weibull modulus m in the range 10–40, it can be calculated by the model that strength measured with a straight-sided specimen will be 1–2% lower than the strength measured with a specific waisted butterfly-shaped specimen solely due to the difference in test specimen shape and volume.