Development of Building Maintenance System for Monitoring Repair and Replacement Histories of Public Facilities

The Korea Water Resources Corporation （K-Water） has encountered four problems during the management of water resources of approximately 1,300 buildings spread throughout the country-degradation, budget constraints, lack of standards, and lack of planning. In this study, we have developed a mechanism for collecting, maintaining, and analyzing ground data for repair and replacement works. Our BMS （building maintenance system） uses the recorded repair and replacement work histories and calculates the life cycle costs of the related items. Further, it enables the performance of repair and replacement tasks through an integrated approach aimed at preventive maintenance. In this manner, the BMS is expected to maximize the efficiency of the formulation of prevention and maintenance work plans, monitoring of work histories, predictions of future tasks from the analyses of repair and replacement histories, and performance of LCC （life cycle cost） calculations. Reliable maintenance of national properties can thus be achieved by using the BMS, which promotes reasonable and efficient repair and replacement activities.

Application of real-time 3d echocardiography in mitral valve repair for replacement of chordae tendineae

Objective To investigate the surgical technique and outcomes of replacement of chordae tendineae in mitral valve repair,and evaluate the value of real-time three-di-mensional transesophageal echocardiography in the perioperative period. Methods Thirty-one patients with mitral valve prolapse underwent mitral valve repair using chordae tendineae replacement concomitant with implantation

Pulmonary Valve Replacement after Repair of Tetralogy of Fallot:A Review

Tetralogy of fallot （TOF） occurs in approximately 1 in 5000 live births and accounts for 12% - 14% of congenital heart disease. Surgical repair was first introduced in the 1950s and there is now a large population of adults with repaired TOF. Some of them may suffer from significant pulmonary regurgitation （PR）, progressive right ventricle （RV） dilation, RV dysfunction and restrictive right ventricular physiology（RRVP）.

CRISPR/Cas: a Nobel Prize award-winning precise genome editing technology for gene therapy and crop improvement

Since it was first recognized in bacteria and archaea as a mechanism for innate viral immunity in the early 2010 s,clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)has rapidly been developed into a robust,multifunctional genome editing tool with many uses.Following the discovery of the initial CRISPR/Cas-based system,the technology has been advanced to facilitate a multitude of different functions.These include development as a base editor,prime editor,epigenetic editor,and CRISPR interference(CRISPRi)and CRISPR activator(CRISPRa)gene regulators.It can also be used for chromatin and RNA targeting and imaging.Its applications have proved revolutionary across numerous biological fields,especially in biomedical and agricultural improvement.As a diagnostic tool,CRISPR has been developed to aid the detection and screening of both human and plant diseases,and has even been applied during the current coronavirus disease 2019(COVID-19)pandemic.CRISPR/Cas is also being trialed as a new form of gene therapy for treating various human diseases,including cancers,and has aided drug development.In terms of agricultural breeding,precise targeting of biological pathways via CRISPR/Cas has been key to regulating molecular biosynthesis and allowing modification of proteins,starch,oil,and other functional components for crop improvement.Adding to this,CRISPR/Cas has been shown capable of significantly enhancing both plant tolerance to environmental stresses and overall crop yield via the targeting of various agronomically important gene regulators.Looking to the future,increasing the efficiency and precision of CRISPR/Cas delivery systems and limiting off-target activity are two major challenges for wider application of the technology.This review provides an in-depth overview of current CRISPR development,including the advantages and disadvantages of the technology,recent applications,and future considerations.

SOME RESULTS ON COMPARISON OF MAINTENANCE POLICIES

In this paper, we study the stochastic comparisons of minimal repair replacement policies in repairable case. We give some results on comparisons of the same unit for different policies and on comparisons of the same policies for different units.