Embryos and juveniles in many organisms repair tissue injuries better than adults. In this issue, Shyh-Chang et al. find that postnatal activation of Lin28a, a gene typically active in embryonic development, promotes better than normal tissue repair in mice, including following ear and digit injuries.

This paper deals with the G/G/R machining system consisting of M operating machines as well as S cold standbys. The concepts of balking and reneging are incorporated which make our model more versatile to deal with real time systems. The broken-down machines are sent to repair facilities consisting of R permanent repairmen. The failure times and repair times are generally identical and independ...

In this paper, we develop an economic production quantity (EPQ) model under machine breakdown and two types of repair (corrective and preventive). also, study the simultaneous effect of holding safety stock and purchasing policy. In order to avoid shortages occurring as a result of the random repair time, in addition to keep safety stock, we suppose that the manufacturer could purchase some qua...

introduction: pilonidal sinus is a common disease in sacrococcygeal area, which mostly caught young people and cause disability, which needs complete rest at home and taking off from work. although the surgical treatment of this problem goes back to the last century, still optimal treatment is a controversy. recent studies have raised different surgical approaches, so that there is no general a...

In Switzerland, infrastructure construction is frequently discussed in regional sustainable development because it causes extensive movements of materials. But construction itself is of decreasing importance in industrial countries, as we expect a down-slow in growth of the built environment. Hence, the focus of research on sustainability is shifting to management of the existing building stock...

purpose: mesh technique is the standard for inguinal hernia repair because of less recurrence,   but it is inferior or equal to sutured technique in case of other post-operative complications   such as chronic pain. this clinical trial set out to compare these two techniques.   materials and methods: a total number of 322 cases of unilateral inguinal hernia in participants   older than 18 years...

Background: Impaired DNA repair mechanism is one of the main causes of tumor genesis. Study of intrinsic radiosensitivity of cancer patients in a non-target tissue (e.g. peripheral blood) might show the extent of DNA repair deficiency of cells in affected individuals and might be used a predictor of cancer predisposition. Methods: Initial radiation-induced DNA damage (ratio of Tail DNA/Head DN...

In this paper we study the steady state availability of main k-out-of-n: F and secondary subsystems having general repair time distribution. When more than k units of main subsystem fail, then the main subsystem shuts off the secondary subsystem. The life time distributions of the main units and that of secondary subsystem are exponentially distributed. A repair facility having single repairman...

today, in a competitive market, service organizations and producers have a great attention to optimization and customer satisfaction in order to become competitive. service organization must reduce the number of arrival, waiting time and service time in the queue to increase the customer satisfaction. in this paper by the aim of queuing theory we analyze the optimal amount of increment in a rep...