Quantification of Chlorides and Sulphates on Concrete Surfaces Using Portable X-ray Fluorescence. Optimization of the Measurement Method Using Monte Carlo Simulation

A correct assessment of the pathologies that can affect a reinforced concrete structure is required in order to define the repair procedure. This work addresses the challenge of quantifying chlorides and sulphates directly on the surface of concrete. The quantification was carried out by means of X-ray fluorescence analysis on the surface of concrete specimens at different points with portable equipment. Concrete prisms were made with different amounts of NaCl and Na2SO4. To avoid the influence of coarse aggregate, a qualitative estimate of the amount of coarse aggregate analyzed has been made, although the results show that there is no significant influence. Monte Carlo simulations were carried out in order to establish the necessary number of random analyses of the mean value to be within an acceptable range of error. In the case of quantifying sulphates, it is necessary to carry out six random analyses on the surface, and eight measurements in the case of quantifying chlorides; in this way, it is ensured that errors are below 10% in 95% of the cases. The results of the study highlight that a portable XRF device can be used in situ to obtain concentrations of chlorides and sulphates of a concrete surface with good accuracy. There is no need to take samples and bring them to a laboratory, allowing lower overall costs in inspection and reparation works.

A New Moth-Flame Optimization Algorithm for Discounted {0-1} Knapsack Problem

The discounted {0–1} knapsack problem may be a kind of backpack issue with gathering structure and rebate connections among things. A moth-flame optimization algorithm has shown good searchability combined with an effective solution presentation designed for the discounted {0-1} knapsack problem. A new encoding scheme used a shorter length binary vector to help reduce the search domain and speed up the computing time. A greedy repair procedure is used to help the algorithm have fast convergence and reduce the gap between the best-found solution and the optimal solution. The experience results of 30 discounted {0-1} knapsack problem instances are used to evaluate the proposed algorithm. The results demonstrate that the proposed algorithm outperforms the two binary PSO algorithms and the genetic algorithm in solving 30 DKP01 instances. The Wilcoxon rank-sum test is used to support the proposed declarations.

Use of Foley catheter in control of internal carotid hemorrhage during endoscopic endonasal surgery

Internal carotid artery (ICA) injuries during endoscopic endonasal surgery (EES) are rare life-threatening events. We describe a technique to manage ICA injuries based on the use of Foley catheters.A 26-year-old female underwent endoscopic transnasal trans-sphenoidal removal of pituitary adenoma. Cerebrospinal fluid leak occurred 4 days postoperatively. During repair procedure, accidental injury of ICA occurred. Emergency nasal packing through positioning of four Foley urologic catheters was successfully performed to stop bleeding. The patient did not report neurologic deficits.In author’s opinion, Foley catheters are suitable to obtain immediate bleeding control since they are rapidly available and easily usable.

Furlow Versus Straight Line Repair With Intravelar Veloplasty: A 7-Year Single Institution Experience with Fistula Formation

Introduction: We aimed to characterize and identify potential risk factors for fistula formation including demographic variables, palatoplasty technique, Veau cleft classification, and adoption status at a large tertiary pediatric facility. Methods: Retrospective chart review was performed for patients undergoing primary palatoplasty via either Furlow or straight line with intravelar veloplasty (IVVP) technique from November 2011 to September 2018. Variables collected included age at time of surgery, gender, language, payer status, adoption status, syndromic status, presence of moderate and/or bilateral hearing loss, Veau cleft type, and presence of a postoperative fistula. Results: Of the 108 patients included, 34 underwent the Furlow procedure and 74 underwent the straight line repair procedure with IVVP. A significant correlation was found between fistula formation and both adoption status and Veau cleft type. Only patients with Veau cleft types 3 and 4 developed a postoperative fistula. Postoperative fistulae developed in 9 patients: 1/34 (2.9%) in the Furlow group and 8/74 (10.8%) in the straight line with IVVP group. Conclusions: At our institution, rate of fistula formation is not greatly different between Furlow and straight line with IVVP palatoplasty techniques despite their being a trend toward increased risk of postoperative fistulas within the latter group, supporting previous literature that did not find an association between technique and fistula rate. Veau cleft classification and adoption status were more closely associated with the formation of postoperative fistulae.

Machine Learning Prediction Models for Mitral Valve Repairability and Mitral Regurgitation Recurrence in Patients Undergoing Surgical Mitral Valve Repair

Background: Mitral valve regurgitation (MR) is the most common valvular heart disease and current variables associated with MR recurrence are still controversial. We aim to develop a machine learning-based prognostic model to predict causes of mitral valve (MV) repair failure and MR recurrence. Methods: 1000 patients who underwent MV repair at our institution between 2008 and 2018 were enrolled. Patients were followed longitudinally for up to three years. Clinical and echocardiographic data were included in the analysis. Endpoints were MV repair surgical failure with consequent MV replacement or moderate/severe MR (>2+) recurrence at one-month and moderate/severe MR recurrence after three years. Results: 817 patients (DS1) had an echocardiographic examination at one-month while 295 (DS2) also had one at three years. Data were randomly divided into training (DS1: n = 654; DS2: n = 206) and validation (DS1: n = 164; DS2 n = 89) cohorts. For intra-operative or early MV repair failure assessment, the best area under the curve (AUC) was 0.75 and the complexity of mitral valve prolapse was the main predictor. In predicting moderate/severe recurrent MR at three years, the best AUC was 0.92 and residual MR at six months was the most important predictor. Conclusions: Machine learning algorithms may improve prognosis after MV repair procedure, thus improving indications for correct candidate selection for MV surgical repair.

Bond strength repair of a bulk-fill composite using different adhesive systems and resin composites

In this study evaluated the effect of different adhesive systems and resin composites on the microtensile bond strength of repairs using a bulk-fill composite. Ninety specimens were prepared using a half-hourglass mold of composite Filtek Bulk Fill using a silicone matrix. Specimens were randomly distributed in 9 experimental groups (n=10) according to adhesive [Universal Single Bond (SBU), Scotchbond Multipurpose Adhesive (SBMP), and Single Bond 2 (SB2)] and resin composite (Filtek Bulk Fill, Aura Bulk Fill, and Filtek Z250). For control group, hourglass specimens were used to measure the ultimate bond strength. Specimens were submitted to thermal cycling (5,000 cycles, 5 and 55°C, 30s) to simulate the aging of restoration and then the repair procedure was performed. After the diamond-tipped surface roughening to be repaired, the adhesive protocol was performed according to group, the specimen was placed in an hourglass-shaped mold and the other half was filled with the repair composite. After 24h, bond strength of specimens was obtained by microtensile using a universal testing machine at a speed of 0.5mm/min. Data were statistically analyzed by two-way ANOVA, Tukey’s and Dunnett’s tests (α=0.05). SBU showed higher bond strength compared to SB2, while SBMP showed intermediate values. However, all experimental groups showed lower bond strength compared to ultimate bond strength. In conclusion, bulk-fill composite repair using universal or conventional solvent-free adhesive improved the adhesion independent of composite tested.

All-arthroscopic repair of Atzei class II and III triangular fibrocartilage complex tears using the FasT-Fix suture device

Background The study is aimed to propose an arthroscopic repair technique using a pre-tied suture device for peripheral TFCC (triangular fibrocartilage complex) tear with proximal component involvement. Methods Through a retrospective review in the medical records of patients who underwent unilateral arthroscopic repair for TFCC Palmer IB lesion between 2017 and 2019, 12 patients were arthroscopically diagnosed as proximal component tear and received more than 1 year follow-up postoperatively. The arthroscope was introduced from 6R portal to discriminate Atzei class II from III lesions by a “visualization test” and to supervise the repair procedure using pre-tied FasT-Fix suture device from 3-4 portal. Two poly-ether-ether-ketone (PEEK) blocks were further advanced along the device needle to finally seat outside the ulnar joint capsule, followed by gradually tightening the pre-tied suture loop until the TFCC periphery was securely repositioned and held stably. Results Operation time averaged 87 min. Hook test and DRUJ arthroscopy confirmed proximal component tear in all 12 wrists. Four patients were diagnosed to be Atzei class II lesion as full thickness tear of distal component was arthroscopically identified from 6R portal while the other 8 exhibited partial thickness tear and were categorized as class III lesion. Follow-up averaged 15 months with a range of 12 to 24 months. Mayo modified wrist score improved from an average of 61.3 preoperatively to 90.4 at the latest visit. Conclusions A modified technique for diagnosis and all-arthroscopic repair in TFCC Atzei class II and III lesions using a pre-tied suture device is a feasible and safe option with promising results.