فصلنامه علوم اعصاب شفای خاتم
سال پنجم شماره 2 (پیاپی 27، بهار 1396)

Efforts have been taken to find appropriate sources to replace liver transplantation. Wharton’s jelly is an unlimited source of stem cells that can be used in cell therapy and tissue engineering. In this study we investigated whether Wharton’s jelly-derived mesenchymal stem cells (WJMSCs) could trans-differentiate into hepatocyte in the presence of mouse liver cell-free extract.
Mesenchymal stem cells (MSCs) were isolated from the umbilical cord. The cells were permeabilized by Sterptolysin O in the presence of mouse liver cell-free extract for 21 days. To evaluate differentiation and morphological changes, immunostaining for cytokeratin 18 and 19 were performed for differentiated and control cells. Functional assays were done by periodic acid Schiff (PAS) stain.
The phenotype of treated MSCs in the presence of liver cell-free extract changed into polygonal cells. Immunostaining demonstrated the expression of cytokeratin 18 and 19 in differentiated cells. Glycogen storage in differentiated cells revealed by PAS staining indicated functional property of differentiated cells.
It seems that factors existing in the extract able to trans-differentiate WJMSCs into functional hepatocyte.

Medical engineering systems nowadays play a very significant role in the diagnosis of various diseases. One of the most applicable devices of the medical engineering are receiving and recording devices of the heart signals, such as electrocardiograph. Application of Holter monitoring devices could be known as one of the substantial methods of electrocardiograph during daily activities. In this article, design and manufacture of Holter monitoring device based-on ARM micro-controller are proposed.
Atmel's SAM3S Chip from the family of ARM has an eleven-channel transformer of analogue to digital which can transform analogue signals to digital values with 12 Bit accuracy by utilizing from ARM architecture used in the core of Cortex-M3 with the structure of Thumb2 processes the information with the speed of 60 MHZ. Furthermore, for receiving and reinforcement of heart signals, INA331 Chip, the product of TI Company was used. Using Chip CYRF6936, signals were transferred to the physician computer with maximum speed of one megabit/sec.
AT91Sam3S with the existence of the Internal Interface Circuit for communication with the external devices has enabled the system to be connected to memory cards and computer without requirement to any other interfaces. This instrumental amplifier with a single-polar feedback has 94dB Common-mode rejection ratio and 54dB amplification ratio. This chip has decreased the consumed power of the vehicle to 330 mW, which by using Lithium- polymer battery of 3000 mAH, the vehicle can be fed for one day without need for charge.
Using wireless communication, keeping the quality of the received signal from body, limitation of information reservation was removed. Furthermore, by simplifying analogue circuits, consumed power of the device was reduced and thus time used from the device was increased without the need for recharge. In addition, by using from low-consumption 32-Bit ARM processor, high processing power and digital process capability on the heart signals will be possible easily.

The performance of health care systems in terms of patient flow times and utilization of critical resources can be assessed through queueing and simulation models. This paper provides a tool for studying the capacity, resources, and patient flow time.
This study was performed in CCU section of the Kosar Hospital, focusing on the impact of outages (preemptive and non-preemptive) on the effective utilization of resources and on the flow time of patients. Two procedures of queueing network solution have been presented; the decomposition and the Brownian motion approaches. Several scenarios have been defined to improve the performances. Simulation has been utilized as a validation tool.
Simulation results show that scenario 2 (reduction of time spent on resolving delays) has the lowest waiting times. Scenarios 4 to 6 show that the proportion of time spent on absenteeism is less than the time spent on the resolving delays.
The queueing models based on decomposition approaches to Brownian motion Approximation present more accurate results. Decreasing the number of interrupts and reducing the time spent on resolving interrupts decrease flow times. The impact of outages is considered a key managerial challenge.

Dealing with work and family are two important aspects of everyone life. Physical and spiritual health depend on the harmony of these two aspects. Especially, in modern societies that employees are spending longer periods at work, addressing different roles in other aspects of life, such as family, friends, community, leisure, etc., has become the main concern. Nurses cannot usually play their role with their family due to high workload and its stress. On the other, nurses cannot usually cover their duties at work because of family problems. This stressful condition causes dismal results for patient care in hospitals.
In this study, using related studies and previous researches in this area, first the conceptual framework was provided, and then, using the Delphi method and the judgment and chains sampling, the pattern of study was designed.
The four-stage Delphi was done and finally multiple dimensions and indicators related to work-life balance enablers were developed according to the Council of Experts.
These dimensions are included individual, organizational and environmental.

DNA ligases as a particular type of enzyme which catalyze and facilitate the formation of a phosphodiester bond in duplex DNA are central enzymes in molecular biology. DNA ligase forms a bond between the end of a donor nucleotide and the end of an acceptor nucleotide. Reaction of DNA ligases is necessary for all organisms and serves as the fundamental step of DNA replication and repair. DNA ligase can play an important role in repairing single strand disruptions and fasten nicks in double-stranded DNA. It also connects Okazaki fragments during the replication of DNA. T4 DNA ligase, E. coli DNA ligase, and thermostable DNA ligases are examples of DNA ligase enzyme family. These enzymes differ in their co-factor requirements, substrate specificity, and thermal stability.
DNA ligase has the widespread use in laboratories of molecular biology for recombinant DNA experiments. Despite the existence and operation of the DNA ligases in all organisms, they show a vast variety of amino acid sequences, molecular sizes, and attributes.

Today''s management is aware of the fact that even with the implementation of total quality management and reengineering¡ organizations will not be able to systematically satisfy the conflicting goals. Comprehensive productivity management philosophy not only consists of management principles by objectives¡ total quality management and reengineering¡ but relies on the most important and most fundamental goal of societies¡ such as improving the material and spiritual welfare.
Therefore¡ the goal of productivity improvements is to maximize the use of manpower resources and facilities to the scientific methods¡ reduce production costs¡ expand markets¡ increase job opportunities¡ increase salaries as well as to improve the living standards for the benefit of employees¡ managers¡ and consumers. Finally improving productivity results in increasing employment opportunities.