An Evaluation of the Cracking Resistance of Steel- and Glass-Fiber-Reinforced Asphalt Mixtures Produced at Different Temperatures

This study focuses on the effects of the production temperatures, warm mix asphalt (WMA) additive, and fiber content on the cracking resistance of steel- and glass-fiber-reinforced asphalt mixtures. By using three different approaches, which included different mixing and compaction temperatures, along with the incorporation of a WMA additive, the samples were produced utilizing the Marshall mix design method. The low-temperature cracking resistance and bottom-up fatigue cracking resistance of the asphalt mixture samples were assessed through indirect tensile (IDT) tests performed at two different test temperatures: −10 °C and 20 °C, respectively. According to the fracture work density values, glass fibers significantly improve the low-temperature cracking performance of asphalt mixtures. Furthermore, it was found that the low-temperature cracking resistance of the hot mix asphalt (HMA) mixtures containing fibers was similar to that of the mixtures prepared using the WMA additive at 15 °C lower mixing and compaction temperatures than the HMA mixtures. To conclude, the WMA additive improved the compactability of the steel- and glass-fiber-reinforced asphalt mixtures without compromising the low temperature cracking performance, despite the low mixing and compaction temperatures

Influence of warm mix additive on internal structure of dry process crumb rubber modified mixtures

© 2021 Elsevier LtdPerformance of asphalt concrete depends highly on its internal structure, which is affected by production temperature, compaction effort and material properties. This study aims to evaluate the internal structure and performance of dry process crumb rubber modified mixtures with warm mix asphalt (WMA) additives. In order to evaluate the effect of WMA additive on these properties, dry process crumb rubber modified WMA mixtures were prepared under different production temperatures applying different compaction efforts. In addition, a radial inhomogeneity analysis tool is developed considering the size fraction and location of aggregate particles, while iPas software is utilized to quantify the contact zone properties. The performance of each test mixture is also evaluated through stability, rutting, and cracking tests. The study outcomes indicate that WMA additive reduces the segregation level of dry process crumb rubber mixtures. In spite of the favorable influence of the WMA additive, there seems a slight decrease in the total contact length and number of contact points of the samples. It is shown that both the control and the WMA mixtures can offer similar performances when compacted at lower temperatures or the same temperature under less compaction effort. The use of DryWMA allows for longer haul distance, less energy for production and limited exposure to fumes during construction

Predictors of in-hospital mortality following redo cardiac surgery: Single center experience

Purpose: Redo cardiac operations represent one of the main challenges in heart surgery. The purpose of the study was to analyze the predictors of in-hospital mortality in patients undergoing reoperative cardiac surgery by a single surgical team. Methods: A total of 1367 patients underwent cardiac surgical procedures and prospectively entered into a computerized database. Patients were divided into 2 groups based on the reoperative cardiac surgery (n = 109) and control group (n = 1258). Uni-and multivariate logistic regression analysis were performed to evaluate the possible predictors of hospital mortality. Results: Mean age was 56 +/- 13, and 46% were female in redo group. In-hospital mortality was 4.6 vs. 2.2%, p = 0.11. EuroSCORE (6 vs. 3; p < 0.01), cardiopulmonary bypass time (90 vs. 71 min; p < 0.01), postoperative bleeding (450 vs. 350 ml; p < 0.01), postoperative atrial fibrillation (AF) (29 vs. 16%; p < 0.01), and inotropic support (58 vs. 31%; p = 0.001) were significantly different. These variables were entered into uni- and multivariate regression analysis. Postoperative AF (OR 1.76, p = 0.007) and EuroSCORE (OR 1.42, p < 0.01) were signifi cant risk factors predicting hospital mortality. Conclusions: Reoperative cardiac surgery can be performed under similar risks as primary operations. Postoperative AF and EuroSCORE are predictors of in-hospital mortality for redo cases

Evaluation of Coronary Artery-Saphenous Vein Composite Grafts: The Aortic No-Touch Technique

We retrospectively compared the results of conventional coronary artery bypass grafting (CABG) performed on patients who showed no preoperative evidence of serious atherosclerosis of the ascending aorta with the results of the aortic no-touch technique (using coronary artery-saphenous vein composite grafts) on CABG patients who did show such evidence. From 2003 through 2012, 3,152 consecutive patients underwent isolated primary CABG at our hospital. We chose 360 for the current study. The study group (n=120) comprised patients who had undergone operation via the aortic no-touch technique. Propensity-score-matching (1: 2) was used to select the control group of 240 patients who had undergone conventional CABG. Early and late survival rates, reintervention-free survival rates, and freedom from cardiac death were compared. Early and late mortality rates were similar in the study and control groups (P=0.19 vs P=0.29, respectively), as were cardiac-related death (2.5% vs 2.1%, respectively; P=0.53) and overall death (8.3% vs 7.9%, respectively; P=0.51). Overall survival rates were 91.7% vs 92.1% and freedom-from-cardiac-death rates were 97.4% vs 97.5% (P=0.71 vs P=0.78, respectively; mean follow-up period, 5.27 +/- 2.51 yr). Reintervention-free survival rates were also similar (96.7% vs 98.8%, respectively; P=0.2). As a result of the similar rates of early and late survival, reintervention-free survival, and freedom from cardiac death, we conclude that the aortic no-touch technique with composite grafts might be a reasonable option in patients who have atherosclerotic ascending aorta that cannot be clamped

Effect of slow-release 5-fluorouracil on capsule formation around silicone breast implants: An experimental study with mice

WOS: 000251090700009PubMed: 17578639Background: Capsule formation around breast implants, development of tendon adhesions after tendon repair, intestinal brits after laparatomies, hypertrophic scars in skin incisions all are the results of excessive collagen synthesis to the extracellular matrix by fibroblasts. Any intervention that leads to cessation of collagen synthesis in these clinical situations may help to prevent these untoward results of wound healing. Although 5-fluorouracil (5-FU) is used mainly as a cytotoxic drug in chemotherapy protocols, it decreases cellular metabolism and blocks protein synthesis only at lower concentrations. Findings have shown that 5-FU downregulates fibroblast proliferation and differentiation in vitro. It has been used to treat fibroproliferative disorders of the eye and skin and is thought to inhibit thymidylate synthetase, blocking DNA replication. Methods: This study used five treatment groups: (1) gelatin only, (2) silicone only, (3) silicone + gelatin, (4) silicone + gelatin containing 1 mg of 5-FU, and (5) silicone + gelatin containing 5 mg of 5-FU. The release kinetics of 5-FU from gelatin have been investigated by means of ultraviolet spectrophotometric analysis. Specimens were obtained on postoperative day 30. Gross evaluation and histopathologic examination were conducted for capsule formation and the development of inflammation. Results: The silicone group had the most prominent capsule formation among all the groups. The gelatin group was second, and the silicone + gelatin group was third. As compared with the other groups, the 5-FU-containing groups had the least capsule formation. The 5-mg 5-FU-containing group had the most inflammation. The silicone + gelatin group was second in inflammation. Although the silicone, gelatin, and 1-mg 5-FU-containing groups had the same means, the results of the silicone group showed the most divergent data within the group. Conclusions: Because 5-FU loaded to a gelatin carrier for its slow release seems to prevent capsule formation around silicone blocks, it may be used to prevent capsule formation around silicone breast implants

Assessment of patients with Takayasu arteritis in routine practice with Indian Takayasu clinical activity score

PubMedID: 26136490Objective. To assess the Indian Takayasu Clinical Activity Score (ITAS2010) in followup of Takayasu arteritis (TA). Methods. ITAS2010 forms were filled in prospectively (n = 144). Clinical activity was assessed with physician's global assessment (PGA) and criteria defined by Kerr, et al. Results. ITAS2010 was significantly higher in patients with active disease. Total agreement between ITAS2010 and PGA was 66.4%, and between ITAS2010 and Kerr, et al was 82.8%. During followup, 14 of 15 patients showing vascular progression with imaging were categorized as having inactive disease according to ITAS2010. Conclusion. ITAS2010 was discriminatory for activity during the followup, but the agreement between PGA and ITAS2010 was moderate. Future work should include the incorporation of advanced vascular imaging and demonstration of ITAS2010 as a scalable measure and not simply a dichotomous measure of activity/flare versus remission. © 2015 The Journal of Rheumatology. All rights reserved

Effect of Use of Slow Release of Bone Morphogenetic Protein-2 and Transforming Growth Factor-Beta-2 in a Chitosan Gel Matrix on Cranial Bone Graft Survival in Experimental Cranial Critical Size Defect Model

Sargon, Mustafa Fevzi/0000-0001-6360-6008; KORKUSUZ, PETEK/0000-0002-7553-3915WOS: 000275061800020PubMed: 20179488Bone grafts, used for providing structural integrity of cranial vault remodeling, could not always integrate with the remaining bone structures. All efforts are focused on increasing incorporation of the applied bone grafts. Allografts were covered by chitosan so that slow release of bone morphogenetic protein-2 (BMP-2) and Transforming growth factor-beta-2 (TGF-beta-2) was achieved. Two hundred forty Wistar-Albino rats were distributed equally in 8 study groups. Study groups were designed as; defect group, autograft group, allograft group, chitosan group, allograft + chitosan, TGF-beta-2 group, BMP-2 group, and TGF-Beta-2 + BMP-2 group. Bone biopsies were obtained at second, eight, and 14th weeks. Bone regeneration was evaluated by morphologic studies detecting histologic bone healing and radiologic studies detecting bone density. Histologic findings were evaluated in 2 categories; tissue response to the implant and defect healing. Additionally, scanning electron microscopy for detailed morphologic evaluation was done. Bone density of the applied scaffold and the parietal bone at the same computed tomography section were measured in Hounsfield scale and this ratio was used for densitometry evaluations. Kruskal-Wallis test was used to analyze difference among groups according to the histologic and radiologic data. Pairwise comparisons were done using Mann-Whitney U test with Bonferroni correction. P < 0.05 was considered significant. In the morphologic studies, bone regeneration in BMP-2 group was found to be compatible with bone regeneration in gold standard autograft group and even better than it within 15 days. Chitosan is a biocompatible material. TGF-Beta-2 alone is not effective enough in bone regeneration; BMP-2 alone has a positive effect in every step of bone regeneration. Combining TGF-Beta-2 with BMP-2 does not lead to a better bone regeneration than using BMP-2 alone. A synergistic effect is not obtained by using these 2 factors together

Assessment of Takayasu's Arteritis Patients with Indian Takayasu Clinical Activity Score (ITAS2010) Improves with the Incorporation of Imaging

WOS: 000440319800189