Mitigating Measurement Inaccuracies in Digital Twins of Construction Machinery through Multi-Objective Optimization.

The advent of digital twins facilitates the generation of high-fidelity replicas of actual systems or assets, thereby enhancing the design's performance and feasibility. When developing digital twins, precise measurement data is essential to ensure alignment between the actual and digital models. However, inherent uncertainties in sensors and models lead to disparities between observed and predicted (simulated) behaviors. To mitigate these uncertainties, this study originally proposes a multi-objective optimization strategy utilizing a Gaussian process regression surrogate model, which integrates various uncertain parameters, such as load angle, bucket cylinder stroke, arm cylinder stroke, and boom cylinder stroke. This optimization employs a genetic algorithm to indicate the Pareto frontiers regarding the pressure exerted on the boom, arm, and bucket cylinders. Subsequently, TOPSIS is applied to ascertain the optimal candidate among the identified Pareto optima. The findings reveal a substantial congruence between the experimental and numerical outcomes of the devised virtual model, in conjunction with the TOPSIS-derived optimal parameter configuration.

Surgical Findings and Outcomes of Endotension Following Endovascular Aneurysm Repair.

BACKGROUND: Endotension is one of the detrimental complications after endovascular aneurysm repair (EVAR) and surgical management has been considered as standard of care. However, there is a paucity of data regarding the findings, and outcomes of such surgical intervention. The aim of this study was to investigate intraoperative findings and outcomes of surgical treatment for endotension after EVAR. METHODS: Between January 2005 and October 2018, of the 708 patients who underwent EVAR for aneurysm aortic aneurysm; 12 patients (mean age of 76.1; range 66-88) who underwent open repair for endotension were retrospectively analyzed. The anatomical characteristics of the aorta and surgical findings were reviewed. The rates of early and late procedural complications, and overall mortality were evaluated. RESULTS: The median interval between the EVAR and surgical conversion was 45.9 months (range 17.1-46.9). Three of the twelve patients underwent emergency surgery due to aneurysm rupture. The median aneurysm sac size, the proximal neck diameter, and the proximal neck length before EVAR were 64 mm, 23.5 mm, and 30.5 mm, respectively, that changed before open repair to 93.5 mm (P = 0.02), 25 mm (P = 0.011), and 23 mm (P = 0.003), respectively. In four of the twelve patients, radiographically undetected endoleak was identified during surgery to be Type Ia, Ib, II, and III, respectively. The rates of early and late procedural complications, and overall mortality were 8.3%, 8.3% and 8.3%, respectively. CONCLUSIONS: Patients with endotension have a risk of delayed endoleak and aneurysm rupture; secondary intervention should be performed in such cases to prevent fatal complications. Surgical treatment appears to be a curative treatment for endotension with favorable outcomes. In addition, the possibility of an undetected endoleak should be considered as a potential cause of endotension.

Clinical Results of Transarterial Embolization to Control Postoperative Vascular Complications after Partial Nephrectomy.

PURPOSE: We evaluated the safety and clinical efficacy of transarterial embolization of vascular complications after partial nephrectomy. MATERIALS AND METHODS: This retrospective study included 1,187 patients who underwent partial nephrectomy between January 2006 and December 2017. A total of 36 patients were referred to the interventional radiology department for vascular complications after partial nephrectomy. Data on demographics, clinical manifestations, angiographic findings, the embolization procedure, perioperative details, and technical and clinical success rates were analyzed. Further, renal function was recorded at diagnosis, after embolization and at the last followup. RESULTS: Hemorrhage was diagnosed a median of 5 days (range 0 to 89) postoperatively. The incidence of requiring embolization due to hemorrhage after laparoscopic surgery (5.9% or 17 of 289 cases) was higher than that after open surgery (1.8% or 8 of 440, p = 0.003) and robot-assisted surgery (2.4% or 11 of 458, p = 0.014). The technical and clinical success rates were 100% (36 of 36 patients) and 94.4% (34 of 36) with 2 patients requiring additional embolization with n-butyl-2-cyanoacrylate glue. The mean ± SD estimated glomerular filtration rate at diagnosis, after embolization and at last followup was 81.0 ± 21.6, 83.7 ± 21.0 and 84.9 ± 15.8 ml/minute/1.73 m2, respectively (p = 0.345). No major complication was observed during followup. CONCLUSIONS: Transarterial embolization is safe and effective for managing vascular complications after partial nephrectomy. Moreover, renal function was well preserved with super selective transarterial embolization.

A micro-architectured material as a pressure vessel for green mobility.

A shellular is a micro-architectured material, composed of a continuous smooth-curved thin shell in the form of a triply periodic minimal surface. Thanks to the unique geometry, a shellular can support external load by co-planar stresses, unlike microlattice, nanolattice, and mechanical metamaterial. That is, the shellular is the only stretching-dominated material with the highest strength at a density of less than 10-2 g/cc. Therefore, it is expected to support internal pressure, too, by the bi-axial tensile stresses like a balloon. For more than 300 years, spherical and cylindrical vessels have been viable yet compromised options for storing pressurized gases. However, emerging green mobility necessitates a safer and more spatially conformable storage solution for hydrogen than spherical and cylindrical vessels these conventional vessels. In this study, we propose to use the shellular as a pressure vessel. Due to the distinct topological nature - periodic micro-cells constituting the triply periodic minimal surface, the alternative pressure vessel can be tailored individually for spatial requirements while ensuring safety with leak-before-break. For a given constituent material and prescribed pressure, the achievable internal volume-per-total weight of a P-surfaced, cold-stretched, double-chambered shellular vessel with a number of cells more than 15 × 15 × 15 can exceed the practical upper bound of both spherical and cylindrical vessels. For the applications, a thin shell with the large surface area of this micro-architecture is ideal for interfacial transfer of heat or mass between its two sub-volumes under internal pressure.

Percutaneous retrograde intramedullary single wire fixation for metacarpal shaft fracture of the little finger.

This study aimed to evaluate the anatomic and functional outcome of retrograde intramedullary single wire fixation for metacarpal shaft fractures of the little finger. Forty consecutive patients with closed metacarpal shaft fractures of the little finger who have been treated with retrograde intramedullary single wire fixation were evaluated. Fracture union and angulation were analyzed radiologically, and clinical evaluations were performed including the percentage of total active motion (%TAM), disabilities of the arm, shoulder and hand (DASH) score, and complications. Fracture union was achieved in all cases, and callus formation was obvious at 42 days postoperatively. The average angulation of the fracture site was 2.7° in the coronal plane and 1.0° in the sagittal plane at the last follow-up, and no measurable metacarpal shortening was observed. Mean %TAM was 92.0 ± 6.2% (range, 84.6-100%), and DASH score was 2.8 ± 1.2 (range, 0-6). There were two cases of pin migration as intermediate complications. A closed reduction with subsequent percutaneous retrograde K-wire fixation produced good radiological and functional results. We recommend this minimally invasive technique which provides adequate fixation of displaced little finger metacarpal shaft fractures with good functional results and low morbidity.

Transcatheter arterial embolization for gastrointestinal bleeding: Clinical outcomes and prognostic factors predicting mortality.

We evaluated clinical outcome and prognostic factors predicting mortality of transcatheter arterial embolization (TAE) for acute gastrointestinal (GI) bleeding. Fifty-nine patients (42 men, 17 women; mean age 66.1 ± 17.0) who underwent 59 TAE procedures for GI bleeding during 2013-2018 were retrospectively evaluated. Clinical outcomes included technical success, adverse events, and rebleeding and mortality rate within 30 days. The technical success rate was 100%. Angiography showed contrast extravasation in 41 (69.5%) patients and indirect signs of bleeding in 16 (27.1%) patients. Two (3.4%) patients underwent prophylactic embolization. TAE-related adverse events occurred in 7 (11.9%) patients; adverse events were more common for mid GI or lower GI bleeding than for upper GI bleeding (22.6% vs 0%, P = 0.007). Rebleeding within 30 days was observed in 22 (37.3%) patients after TAE. Coagulopathy was a prognostic factor for rebleeding (odds ratio [OR] = 3.53, 95% confidence interval 1.07-11.67, P = .038). Mortality within 30 days occurred in 11 (18.6%) patients. Coagulopathy (OR = 24, 95% confidence interval 2.56-225.32, P = .005) was an independent prognostic factor for mortality within 30 days. TAE is an effective, safe, and potentially lifesaving procedure for GI bleeding. If possible, coagulopathy should be corrected before TAE as it may reduce rebleeding and mortality.

A Microscopic Shell Structure with Schwarz's D-Surface.

Recently, materials with micro-architecture of hollow trusses and ultralow density (less than 10-2 Mg/m3) have gained attention. The materials have been fabricated by forming templates based on 3D lithographical techniques, followed by hard coating on the surface, and finally etching out the template. Here, we describe a novel fabrication method for another micro architecture composed of a single continuous smooth-curved shell with D-surface, named Shellular; its template is prepared based on weaving flexible polymer wires. Compression test results reveal that these D-surfaced Shellulars have strength and Young's modulus comparable to those of their hollow truss-based competitors. The best virtue of this weaving-based technology is its mass-productivity and large-size potential. Also, this technology can be applied to fabricate not only D-surfaced but also P- or G-surfaced Shellular. The unique geometry of Shellular, composed of a single continuous, smooth, and interfacial shell or membrane separating two equivalent sub-volumes intertwined with each other, appears to possess huge application potential such as non-clogging tissue engineering scaffolds and compact light-weight fuel cells with high energy density.

A New Type of Low Density Material: Shellular.

A new type of cellular material named Shellular, in which cells are composed of a continuous, smooth-curved shell according to the minimal surface theory, is proposed. Shellular specimens are fabricated using 3D lithography with negative templates and hard coating, and exhibit superb strength and stiffness at densities lower than 10(-2) Mg m(-3), incorporating benefits from hierarchical structures and constituent materials with nanosized grains.

Degeneration of leiomyoma in patients referred for uterine fibroid embolization: incidence, imaging features and clinical characteristics.

PURPOSE: Imaging features and clinical characteristics of degenerated leiomyoma in patients referred for uterine fibroid embolization (UFE) were analyzed to assess the incidence of degenerated leiomyoma. MATERIALS AND METHODS: Patients referred for UFE between 2008 and 2009 were retrospectively analyzed (n=276). Patients ranged in age from 27 to 51 years (mean 38.0 years). All patients underwent screening MRI with contrast enhancement. Medical histories and clinical symptoms were evaluated. RESULTS: Among the 276 patients who underwent MRI, 14 (5.1%) showed degenerated leiomyomas. Symptoms were abdominal pain (n=4, 26.7%), menorrhagia (n=5, 35.7%) and bulk-related symptoms (n=5, 35.7%) and no symptoms (n=5, 35.7%). Of the 14 patients with degenerated leiomyomas, 5 (42.9%) had a history of pregnancy in the past two years. For T1-weighted imaging (T1WI), a high signal intensity (SI) of the leiomyoma was the most common finding (n=9, 64.3%) and a hyperintense rim (n=4, 28.6%) was the second most common. On T2-weighted imaging (T2WI), a low SI of the leiomyoma was found in six patients (42.9%), a high SI in four (28.6%) and a heterogeneous SI in four (28.6%) patients. Conservative management was performed in 11 (78.6%) patients, surgery in 3 (21.4%) and uterine artery embolization in one (7.1%) patient. CONCLUSION: The incidence of degeneration of leiomyoma in patients referred for UFE was 5.1%. Patients presented with variable clinical symptoms with or without a history of pregnancy. MR imaging showed a high SI on T1WI and various SIs on T2WI without contrast enhancement. An understanding of the degeneration of leiomyomata is essential when considering UFE.