Mechanism of Thermochromic and Self-Repairing of Waterborne Wood Coatings by Synergistic Action of Waterborne Acrylic Microcapsules and Fluorane Microcapsules

The fluorane thermochromic microcapsules and waterborne acrylic resin microcapsules were added into waterborne coatings at the same time to prepare intelligent waterborne coating film with dual functions of color change and self-repairing. The coating film prepared by adding 15.0% fluorane microcapsules and 5.0% waterborne acrylic resin microcapsules to the primer at the same time had better comprehensive properties. At this time, the coating film changed from yellow to colorless. The repair rate of the coating film was 58.4%. When the temperature was lower than 32 °C, waterborne acrylic resin microcapsules can improve the thermochromic performance of the coating film with fluorane microcapsules. Waterborne acrylic resin microcapsules can alleviate the color change of coating film with fluorane microcapsules. The fluorane microcapsules can improve the self-repairing performance of coating film with waterborne acrylic resin microcapsules. The results lay a theoretical and technical foundation for multifunctional coating film.

Mathematical Modeling of Integral Characteristics of Repair Process under Maintenance Contracts

The repair rate is a very important parameter for system maintainability and can be defined as a frequency of successfully performed repair actions on a failed component per unit of time. This paper analyzes the integral characteristics of a stochastic repair rate for corresponding values of availability in a system operating under maintenance contracts. The probability density function (PDF) of the repair rate has been studied extensively and it was concluded that it is not a symmetric function so its mean value does not correspond to its maximum. Based on that, the equation for the envelope line of the PDF maximums of the repair rate has been provided. Namely, instead of repair rate PDF equations, we can use envelope line parameters for certain calculations, which are expressed in a simpler mathematical form. That will reduce time required for calculations and prediction and enhance reactions in failure events. Further, for the analytical and numerical evaluation of a system performance, the annual repair rate PDFs are analyzed, such as particular solutions of corresponding differential equation, while the existence of a singular solution is considered and analyzed under different conditions. Moreover, we derived optimal values of availability for which the PDF maximums have been obtained. Finally, in order to generalize the behavior of the repair process, a partial differential equation, as a function of the repair rate process and availability parameter, has been formed.

Combination Therapy of Metadichol Nanogel and Lipocalin-2 Engineered Mesenchymal Stem Cells Improve Wound Healing in Rat Model of Excision Injury

Purpose: Currently, several disorders including burns, trauma, excisional and diabetic wounds, and bedsores threaten the human health. Application of mesenchymal stem cells (MSCs) is recommended for treatment of skin disorders. However, because of oxidative stress and inflammation after skin injury, survival of transplanted MSCs is low which in turn negatively affects the efficiency of the MSCs-based therapy. In an attempt to address the aforementioned challenge and introducing a novel potential therapeutic strategy, we employed combination therapy by Lipocalin (Lcn2)-engineered MSCs and a Metadichol (an inverse agonist of vitamin D receptor (VDR)) nanogel in a rat model of excisional wound. Methods: First, Human umbilical cord MSCs (hUC-MSCs) was transfected by a recombinant plasmid encoding Lipocalin 2 (Lcn2) gene. Next, a combination of Metadichol nanogel and the engineered MSCs was co-applied on wound in rat model of excision injury. Finally the improvement of wound healing in experimental groups was evaluated by photography and histological assessments (hematoxylin and eosin staining). Results: Our findings revealed that the repair rate was higher in the group received combination therapy comparing to control groups. Notably, Metadichol+Lcn2-MSCs showed significantly higher wound contraction rate compared to control group at all time points (p value< 0.001). Furthermore, wound repair rate was 95% 14 days after surgery, and 100% after 21 days in the treatment groups. Our results also revealed that the combination therapy improved and accelerated the wound healing process. Conclusion: Our findings suggest a novel potential therapeutic strategy i.e. Lcn2-engineered MSCs and Metadichol for wound healing. However, further preclinical and clinical studies are required.

Early and Mid-term Results of Mitral Valve Repair in Patients with Degenerative Mitral Regurgitation

Objectives: In this study, we present the mid-term results of patients who underwent valve repair due to degenerative mitral valve regurgitation in the first five years of our mitral valve repair program. Patients and Methods: In this retrospective study, all patients who were operated for degenerative mitral regurgitation by a single surgical team between 2013 and 2017 were investigated. We determined early and mid-term cumulative survival rates, repair failure and freedom from reoperation. In addition, as a specific subgroup, the results of patients under 18 years of age after mitral valve repair were investigated Results: Mitral repair was performed in 121 of 153 degenerative mitral regurgitation patients during the study period. The overall repair rate was 79%. Mitral valve repair rate increased significantly over years. The Median follow-up time was 63 (range 10-92) months. Early mortality was 2.5% (n=3 patients). During the follow-up period, moderate-to-severe mitral regurgitation was observed in 14 (11.8%) patients, mitral valve reoperation was required in 7 (5.9%) patients. Valve repair was performed in 4 of 7 patients under the age of 18. There was no pediatric case requiring reoperation during the follow-up period (median 46 months). Conclusion: Mid-term results of mitral valve repair in degenerative mitral valve patients are satisfactory. The success rate of repair increases in line with surgical experience.

Optimal Method for Test and Repair Memories Using Redundancy Mechanism for SoC

The current system-on-chip (SoC)-based devices uses embedded memories of enormous size. Most of these systems’ area is dense with memories and promotes different types of faults appearance in memory. The memory faults become a severe issue when they affect the yield of the product. A memory-test and -repair scheme is an attractive solution to tackle this kind of problem. The built-in self-repair (BISR) scheme is a prominent method to handle this issue. The BISR scheme is widely used to repair the defective memories for an SoC-based system. It uses a built-in redundancy analysis (BIRA) circuit to allocate the redundancy when defects appear in the memory. The data are accessed from the redundancy allocation when the faulty memory is operative. Thus, this BIRA scheme affects the area overhead for the BISR circuit when it integrates to the SoC. The spare row and spare column–based BISR method is proposed to receive the optimal repair rate with a low area overhead. It tests the memories for almost all the fault types and repairs the memory by using spare rows and columns. The proposed BISR block’s performance was measured for the optimal repair rate and the area overhead. The area overhead, timing, and repair rate were compared with the other approaches. Furthermore, the study noticed that the repair rate and area overhead would increase by increasing the spare-row/column allocation.

Shifting from postauricular to transcanal microscopic tympanoplasty may have similar frequency-specific improvements with better air-bone-gap closure at low frequencies and a minimal learning-curve effect

The shift from postauricular to transcanal microscopic tympanoplasty brings potential advantages of minimal morbidity, less postoperative pain, patient comfort, and surgical ease and speed, but also uncertainties of unfamiliar grafting material, an inadequate operation view, and an uncertain learning curve. These challenges might affect the successful repair rate and the frequency-specific hearing outcome, which is important for hearing perception. Rare studies reported frequency-specific hearing outcome with the learning curve for shifting from postauricular to transcanal microscopic tympanoplasty. Here, from Jul. 2013 to Nov. 2018, we compared patients in a shift from postauricular approach (35 ears) to transcanal approach (35 ears) of microscopic type-1 tympanoplasty. The results show that both of postauricular and transcanal microscopic tympanoplasties reduced the mean air-bone gap, 0.5k Hz gap, and 1k Hz gap after the surgery. The further analyses on gap change as a function of frequency (0.5, 1, 2, and 4k Hz) show that both of postauricular and transcanal tympanoplasties improved postoperative air-bone gap among the levels of frequency. The post hoc comparisons display a common gap reduction difference between 0.5k and 4k Hz. The successful repair rate did not differ between the 2 groups. There was no correlation between the postoperative mean gap change and the surgery date, suggesting a minimal learning-curve effect. The results of similar frequency-specific improvements and a minimal learning-curve effect may help to ease the concerns of those uncertainties before the shift.

Simultaneous Planning of Production, Setup and Maintenance for an Unreliable Multiple Products Manufacturing System

The work presented in this paper addresses the problem of joint optimization of the production, setup and corrective maintenance activities of a manufacturing system. This system consists of a machine subject to breakdowns and repairs and producing two types of parts. A corrective maintenance strategy whose repair rate depends on the number of setup operations already performed on the production system is considered in this work. The objective of this research is to propose a policy that controls production, setup, and corrective maintenance. The contribution of this paper is through the control of the repair rate, combined with the planning of production and setup in a dynamic and stochastic context. Optimality conditions in the form of Hamilton-Jacoby-Bellman (HJB) equations are obtained and a numerical approach is proposed in order to deal with the joint optimization issues. Extensive simulations are performed to address many scenarios that illustrate the interactions between production, setup and maintenance activities.

Does practice of meniscus surgery change over time? A report of the 2021 ‘THE MENISCUS’ Webinar

Purpose The aim of this paper was to report the results presented in the session “Does practice of meniscus surgery change over time?” of the 2021 MENISCUS webinar held online on January 30th 2021. Method During the 2021 MENISCUS webinar, an evaluation of meniscus surgery practices was performed by analyzing: (1) The presentation of the results of a survey conducted among ESSKA members and assessing their current practices in the field of meniscus surgery, (2) Four reports by national experts analyzing the trends in Arthroscopic Partial Meniscectomy (APM) and meniscus repair procedures in their respective countries (France, Belgium, Germany and Japan). Results (1) ESSKA Survey: Among the 461 respondents, 75% of surgeons claimed to perform more meniscus repairs and 85% less APM than 5 years ago. In ACL-associated meniscus injuries, a majority of surgeons (60%) indicated to perform a meniscal resection in less than 25% of cases. 25% declared to perform meniscus repair in ACL-associated meniscus injuries in less than 25% of cases and 37% in more than 50% of cases. Half of the respondents repair medial or lateral root tears in less than 25% of cases. Less than 20% of respondents were not familiar with the ESSKA consensus. (2) National trends: In France, between 2005 and 2017, the APM rate decreased by 21.4%, while the repair rate increased by 320%. In Belgium, between 2007 and 2017, the APM rate decreased by 28.6%. In Germany, between 2010 and 2017 the number of APM decreased by 30%, while the number of repair procedures increased by 55%. Finally, in Japan, between 2011 and 2016, the APM ratio (APM/meniscus procedures) decreased by 16% from 91 to 75% while the repair ratio increased from 9 to 25%. Conclusion The 2021 ESSKA members' survey as well as statistics from 4 specifically examined countries (Belgium, France, Germany and Japan) suggest there has been a significant shift over the last years in the surgical management of meniscal lesions towards less APM and more conservative treatments.