艾叶油乳-水凝胶贴膏剂的制备与透皮研究

目的制备艾叶油乳-水凝胶贴膏剂,并优化其处方和评价其体外透皮性能。方法以初黏力、持黏力、180°剥离强度、内聚力和渗透度为评价指标,选择水凝胶贴膏剂骨架材料聚丙烯酸钠NP-700、交联剂甘羟铝、交联调节剂乙二胺四乙酸二钠(EDTA)和保湿荆甘油,开展正交优化试验。采用GC法测定样品液中桉油精、樟脑、龙脑的量,考察其体外透皮情况。结果影响贴膏剂成型的因素顺序为甘油甘羟铝EDTA聚丙烯酸钠NP-700,最佳组合为30%甘油、5%聚丙烯酸钠NP-700、0.3%甘羟铝、0.03%EDTA。3种成分的稳态渗透速率分别为85.216、4.442、3.941μg/(cm~2.h)。结论艾叶油乳-水凝胶贴膏剂符合质量要求,透皮释药具有零级释放特点。     

微创开髓及其牙体的应力分析的研究进展

微创开髓(conservative endodontic access cavity,CEC)是微创根管治疗术的第一步,经CEC治疗后的患牙较大程度保留了牙尖嵴和颈周牙本质等牙体硬组织,对于减少患牙的牙体流失及增强远期疗效具有重要意义。CEC存在多种入路方式及相应的洞型。确定髓腔入路的方法包括X线片定位法、显微CT/锥形束CT定位法以及数字化导板定位法。其中,X线片、显微CT/锥形束CT定位法操作简便,临床较为常用;而较为复杂的根管系统,利用数字化导板可建立更精准的开髓通路,减少牙体硬组织不必要的丧失,但数字化导板定位价格较高,临床上并未得到广泛的应用。CEC的洞型包括微创开髓洞型、超保守微创开髓洞型、"Truss"洞型以及切端洞型。CEC洞型与传统开髓洞型的应力分析目前以万能力学试验机加载离体牙、有限元分析法及临床观察为主,大多数学者的研究显示保留较多牙体组织的CEC可提高牙齿的抗折强度,但二者之间的抗折能力仍存在争议,在达到牙髓治疗目的与最大限度保留牙体结构之间如何达到平衡,仍需进一步的探索。     

基于微视频健康宣教对初产妇产后康复效果的影响

目的　探究微视频健康宣教对初产妇产后康复效果的影响。方法　选择2019年3月至2021年3月瑞金市人民医院收治的60例初产妇为本次研究对象,采用双盲法分为两组,各30例。对照组年龄（30.34±2.22）岁,接受常规干预;观察组年龄（30.25±2.15）岁,基于对照组进行微视频健康宣教。比较组间康复指标及产后抑郁情况、性功能、盆底肌力恢复情况。计量资料组间比较采用独立样本t检验,组内采用配对t检验,计数资料用χ²检验。结果　观察组子宫复旧时间、恶露持续时间、泌乳时间、爱丁堡产后抑郁量表（EPDS）评分分别为（7.02±1.02）周、（5.21±0.81）d、（2.71±0.32）d、（5.05±0.72）分、（145.52±10.26）ml,均低于对照组［（8.01±1.15）周、（7.36±1.05）d、（3.52±0.52）d、（7.65±1.02）分、（123.21±9.15）ml］,泌乳量多于对照组,差异均有统计学意义（均P<0.05）。干预前,两组初产妇性高潮、性交痛、性欲、阴道润滑、性生活满意度、性唤起评分及总分比较,差异均无统计学意义（均P>0.05）;干预后,观察组性高潮、性交痛、性欲、阴道润滑、性生活满意度、性唤起评分及总分均高于对照组,差异均有统计学意义（均P<0.05）。观察组产后盆底肌力3～5级恢复率分别为26.67%（8/30）、33.33%（10/30）、30.00%（9/30）,均高于对照组的6.67%（2/30）、10.00%（3/30）、6.67%（2/30）,1～2级恢复率分别为3.33%（1/30）、6.67%（2/30）,均低于对照组的40.00%（12/30）、36.67%（11/30）,差异均有统计学意义（均P<0.05）。结论　初产妇产后予以微视频健康宣教可促进产后相关指标的改善,改善性功能及盆底肌力,应用效果显著。     

Evaluation of the Effect of the Loading Time on the Microtensile Bond Strength of Various Restorative Materials Bonded to Silver Diamine Fluoride-Treated Demineralized Dentin

The aim of this study was to evaluate the effect of immediate versus delayed loading times on the microtensile bond strength (μTBS) of restorative materials, including resin-based composite (RBC), resin-modified glass ionomer cement (RMGIC) and glass ionomer cement (GIC), that were bonded to silver diamine fluoride (SDF)-treated demineralized dentin. Ninety caries-free extracted premolar teeth were assigned to three groups (n = 30) loaded with RBC, RMGIC and GIC restorative materials. Each group was further divided into three subgroups (n = 10): subgroup A (control specimens), immediate loading of the restorative material on sound dentin; subgroup B, demineralized dentin, SDF treatment and immediate loading of the restorative material; and subgroup C, demineralized dentin, SDF treatment and restorative material loading a week later. One-way ANOVA and Tukey’s post-hoc tests were performed to compare the μTBS values. The RBC exhibited the highest µTBS, followed by RMGIC and GIC. Multiple comparisons showed an increase in the µTBS in the delayed loading groups irrespective of the restorative material used. The majority of the failure modes were adhesive. Delayed loading of RMGIC for 1 week after SDF application showed significantly higher µTBS than that of immediate loading.     

Influence of Cross-Section Shape and FRP Reinforcement Layout on Shear Capacity of Strengthened RC Beams

The evaluation of the shear capacity of an FRP-strengthened reinforced-concrete beam is challenging due to the complex interaction between different contributions provided by the concrete, steel stirrup and FRP reinforcement. The shape of the beam and the FRP inclination can have paramount importance that is not often recognized by the models that are suggested by codes. The interaction among different resisting mechanisms has a significant effect on the shear capacity of beams, since it can cause a reduction in the efficiency of some resisting mechanisms. A comparative study of the performance in the shear resistance assessment provided by three models with six different effectiveness factors (R) is performed, considering different cross-section shapes, FRP wrapping schemes, inclination and anchorage systems. The results revealed that the cross-section shape, the FRP inclination and the efficiency of the FRP anchorages have a significant effect on the shear strength of beams. The analysis results show that the three models are able to provide an accurate average estimation of shear strength (but with a coefficient of variation up to 0.35) when FRP reinforcement orthogonal to the beam axis is considered, while a significant underestimation (up to 19%) affected the results for inclined FRP reinforcement. Moreover, all the models underestimated the resistance of beams with a T section.     

Effect of Calcium Carbide Residue on Strength Development along with Mechanisms of Cement-Stabilized Dredged Sludge

The purpose of this research is to explore the feasibility of using calcium carbide residue (CCR), a by-product from acetylene gas production, as a solid alkaline activator on the strength development in CCR–Portland cement-stabilized dredged sludge (CPDS). The effects of cement content, CCR content and curing time on the strength development of CPDS were investigated using a series of unconfined compressive strength (UCS), pH and electric conductivity (EC) tests. Scanning electron microscopy and X-ray diffraction analyses were performed to gain additional insight into the mechanism of strength development. Meanwhile, the carbon footprints of CPDS were calculated. Following the results, it was found that CCR can significantly improve the strength of cemented dredged sludge. On the basis of the strength difference (ΔUCS) and strength growth rate (UCS_gr), it was recommended that utilizing 20% cement with the addition of 20% CCR is the most effective way to develop the long-term strength of CPDS. In addition, the microstructural analysis verified that the optimum proportion of CCR benefits the formation of hydration products in CPDS, particularly needle-like gel ettringite, resulting in a less-porous and dense inter-locked structure. Furthermore, the solidification mechanism of CPDS was discussed and revealed. Finally, it was confirmed that CCR can be a sustainable alternative and effective green alkaline activator for the aim of improving cemented dredged sludge.     

Concrete Durability after Load Damage and Salt Freeze–Thaw Cycles

To determine how the performance of concrete changes after initial load damage and salt freezing, concrete samples were first subjected to loading and unloading, and were then put into salt solutions to carry out rapid freeze–thaw cycle (FTC) experiments. Salt solutions were created based on the saline soil of western Jilin, China, for use in salt freeze–thaw testing. This determined the change law of the compressive strength and the dynamic elastic modulus (DEM). Additionally, low-field nuclear magnetic resonance technology and a scanning electron microscope were applied to investigate the pore characteristics and microstructure of concrete samples after FTCs. This study found that when the concrete specimens were subjected to an initial load of 0.3f under 50 FTCs, the loss in the compressive strength increased by 24% when the concrete was subjected to freeze–thaw cycles in freshwater and increased by 24% when concrete was subjected to freeze–thaw cycles in a 6.8% composite salt solution compared with the specimens without the initial load. When the concrete was subjected to FTCs in a 6.8% composite salt solution 50 times, the loss in the compressive strength increased by 110% for concrete without an initial load and increased by 109% when the concrete was subjected to an initial load of 0.3f compared with the specimens under FTCs in freshwater. The persistent effect of the FTCs also aggravated chloride ion erosion in the concrete, which gradually reduced the concrete’s permeability resistance. Internal pores in the concrete, especially the proportion of above-medium-sized pores, gradually increased along with the increase in the number of FTCs. There is a good linear correlation between the change rule of compressive mechanical properties and the change rules of mass, DEM, and pore characteristics inside the concrete under rapid FTCs in different salt solutions.     

手法复位结合中药熏洗对踝关节骨折患者等速肌力的影响

目的观察中医手法复位结合中药熏洗对踝关节骨折患者踝关节周围的等速肌力的影响。方法60例踝关节骨折患者随机分为中医组和手术组,各30例。临床愈合后一年半左右进行随访,分析比较两组患者踝关节肌力的等速测试指标。结果手术组患足踝关节肌力的等速测试指标明显低于中医组。结论中医综合治疗有利于踝关节骨折患者踝关节周围肌力的恢复。     

力量支持协同护理模式在经口喂养不耐受<34孕周新生儿中的应用

目的:探讨力量支持协同护理模式在经口喂养不耐受<34孕周新生儿中的应用效果。方法:选取2019年1月—2020年8月收治的102例<34孕周经口喂养不耐受新生儿作为研究对象,将2019年1月—2019年10月接受常规护理的51例患儿作为对照组,将2019年11月—2020年8月接受力量支持协同护理模式的51例患儿作为观察组。比较两组经口喂养进程(留置胃管时间、过渡时间、住院时间)、喂养效率及患儿行为状态变化。结果:观察组患儿留置胃管时间、过渡时间、住院时间均短于对照组(P<0.05);观察组患儿干预第3天、实现全口喂养时吸吮效率和喂养效率均高于对照组(P<0.05);观察组患儿干预3 d、干预5 d后行为状态优于对照组(P<0.05)。结论:力量支持协同护理模式能有效改善早产儿经口喂养表现,减轻经口喂养不耐受症状,进一步推进经口喂养进程,缩短经口喂养过渡时间。     

Research on Design and Performance of Self-Compacting Cement Emulsified Bitumen Mixture (CEBM)

To meet the needs of the road industry for maintenance operations, a new cement emulsified bitumen mixture (CEBM) with early-strength, self-compacting, and room-temperature construction characteristics was designed. The strength formation mechanism of CEBM was revealed with a scanning electron microscope (SEM) and the surface free energy (SFE) theory. The mechanical properties and road performance of the CEBM were investigated extensively. The results show that before the demulsification of emulsified bitumen, the SFE of the bitumen–aggregate–water three-phase system was reduced due to the replacement of the bitumen–aggregate interface with water. The adhesion work between the emulsified bitumen and the aggregate is negative, which means the adhesion between the emulsified bitumen and the aggregate will not occur spontaneously due to the existence of water. The liquid emulsified bitumen improves the workability of the mixture and ensures that the mixture can be evenly mixed and self-compacted. After demulsification, the work of adhesion between the residual bitumen and the aggregate is positive, which means residual bitumen and aggregate can bond spontaneously. In addition, the hydration products of cement and aggregate form a skeleton, and the emulsified bitumen film wraps and bonds the cement and aggregate together, creating strength. The emulsified bitumen, cement content, and curing conditions have significant effects on the stability of CEBM. The recommended dosage of emulsified bitumen and cement is 8% and 8–10%, respectively. This material integrates the hardening effect of cement and the viscoelastic performance of bitumen and has good workability, mechanical properties, and road performance. Therefore, the CEBM is technically feasible for application to bitumen pavement.