Search

Ultrahigh-performance concrete (UHPC) is susceptible to various forms of abrasion during its service life. This study is an investigation of the abrasion resistance of UHPC, focusing on two primary causes of wear: dynamic traffic loads and hydraulic impacts. To enhance the material's resistance to abrasion, milling steel fibres were utilised. For comparative purposes, straight steel fibres and hybrid milling–straight steel fibres were also employed. The protective function of the steel fibres primarily comes into effect once the concrete cover has experienced wear. When subjected to traffic and hydraulic loads, UHPC containing milling fibres exhibited superior resistance, compared with that containing straight fibres, while maintaining favourable workability. Notably, the UHPC incorporating hybrid steel fibres, which form a composite skeleton, owing to the presence of two fibre types, demonstrated even greater effectiveness in resisting external abrasion. Furthermore, the abrasion resistances observed under both traffic and hydraulic conditions displayed a positive linear correlation, with R2 > 0.8. These findings suggest the feasibility of evaluating the material's abrasion resistance under various wearing causes using a single test method. The outcomes of this study hold promise in advancing the development of UHPC and promoting its utilisation in conditions characterised by severe abrasion. [ABSTRACT FROM AUTHOR]

Background and aim: The clinical outcome of endoscopy submucosal dissection with subsequent radiotherapy for esophageal squamous cell carcinoma remain unclear. In this study we aim to investigate the efficacy and safety of endoscopic submucosal dissection with adjuvant radiotherapy in the treatment of superficial esophageal squamous cell carcinoma involving the muscularis mucosae (T1a-MM) or the submucosa < 200 μm (T1b-SM1). Methods: We analyzed 20 patients with pathologically confirmed T1a-MM or T1b-SM1 esophageal squamous cell carcinoma treated by endoscopic submucosal dissection from 2016 to 2020 in Lihuili Hospital, 9 patients received adjuvant radiotherapy (RT group) and 11 patients received did not (non-RT group). Results: All 20 patients underwent en bloc resection, and both the vertical and horizontal margins were negative. There was no recurrence or lymph node metastasis in the RT group, and no serious complications or death were observed. In the non-RT group, 2 patients had local recurrence and 1 had distant metastasis. None of the 20 patients died of esophageal carcinoma. Conclusions: Adjuvant radiotherapy following endoscopic submucosal dissection may be a safe and effective method for the treatment of T1a-MM/T1b-SM1 superficial esophageal squamous cell carcinoma. [ABSTRACT FROM AUTHOR]

Objectives: This study evaluated the feasibility and safety of zone 1 thoracic endovascular aortic repair (TEVAR) with fenestrated surgeon-modified stent-graft (SMSG) for aortic arch pathologies. Methods: Between March 2016 and November 2020, 34 consecutive patients underwent zone 1 TEVAR with fenestrated SMSG for aortic arch pathologies. Outcomes included technical success, perioperative, and follow-up morbidity and mortality. Results: During the study period, 34 patients were treated with zone 1 TEVAR with fenestrated SMSG. Twenty-four (70.6%) patients presented with type B aortic dissections, 9 (26.5%) patients presented with aneurysms (7 located on the lesser curvature side of aortic arch), 1 (2.9%) patient presented with type Ia endoleak after previous TEVAR owing to traumatic aortic dissection. The proximal landing zone for all patients were in zone 1, and all supra-aortic trunks were reconstructed, except for one left subclavian artery. Technical success was achieved in all cases. The 30-day estimated survival (±SE) was 90.9% ± 5.0% [95% confidence interval (CI): 77.0%–97.0%]. The 30-day estimated freedom from reintervention (±SE) was 87.9% ± 5.7% (95% CI: 73.4%–95.3%). At a median follow-up of 48 months (range, 12–68 months), 2 patients died, including 1 aortic-related death and 1 non-aortic-related death. One patient had reintervention 13 months after the operation owing to type Ia endoleak. All supra-aortic trunks were patent. The estimated survival (±SE) during follow-up was 85.1% ± 6.2% (95% CI: 69.9%–93.6%). One (2.7%) patient had stroke. The estimated freedom from reintervention (±SE) during follow-up was 84.2% ± 6.5% (95% CI: 69.9%–93.5%). Conclusions: Zone 1 TEVAR with fenestrated SMSG is an alternate option for treatment of aortic arch pathologies in experienced centers. [ABSTRACT FROM AUTHOR]

The performance of completely recycled sand is significantly different from that of river sand, and the plastering mortar prepared with completely recycled sand cannot be calculated by the existing design method of plastering mortar mix ratio. A study was conducted on the effect of completely recycled sand on the performance of plastering mortar under different cement dosage. The results show that: under the same dosage of cement, the water demand and the compressive strength at 28d of completely recycled sand plastering mortar are higher than that of river sand mortar; the law of water consumption and 28d compressive strength of completely recycled sand plastering mortar changing with cement dosages are basically the same as that of river sand plastering mortar; according to the experimental results and referring to the existing mortar mix design methods, a mix design method of completely recycled sand plastering mortar is proposed. [ABSTRACT FROM AUTHOR]