The First Experience of Ex-Vivo Lung Perfusion (EVLP) in Iran: An Effective Method to Increase Suitable Lung for Transplantation.

BACKGROUND: Although lung transplantation is a well-accepted treatment for end-stage lung diseases patients, only 15%-20% of the brain-dead donors' lungs are usable for transplantation. This results in high mortality of candidates on waiting lists. Ex-vivo lung perfusion (EVLP) is a novel method for better evaluation of a potential lung for transplantation. OBJECTIVE: To report the first experience of EVLP in Iran. METHODS: The study included a pig in Vienna Medical University, Vienna, Austria, and 4 humans in Masih Daneshvari Hospital, Tehran, Iran. All brain-dead donors from 2013 to 2015 in Tehran were evaluated for EVLP. Donors without signs of severe chest trauma or pneumonia, with poor oxygenation were included. RESULTS: An increasing trend in difference between the pulmonary arterial pO2 and left atrial pO2, an increasing pattern in dynamic lung compliance, and a decreasing trend in the pulmonary vascular resistance, were observed. CONCLUSION: The initial experience of EVLP in Iran was successful in terms of important/critical parameters. The results emphasize on some important considerations such as precisely following standard lung harvesting and monitoring temperature and pressure. EVLP technique may not be a cost-effective option for low-income countries at first glance. However, because this is the only therapeutic treatment for end-stage lung disease, it is advisable to continue working on this method to find alternatives with lesser costs.

Investigation of micro- and nanosized particle erosion in a 90° pipe bend using a two-phase discrete phase model.

This paper addresses erosion prediction in 3-D, 90° elbow for two-phase (solid and liquid) turbulent flow with low volume fraction of copper. For a range of particle sizes from 10 nm to 100 microns and particle volume fractions from 0.00 to 0.04, the simulations were performed for the velocity range of 5-20 m/s. The 3-D governing differential equations were discretized using finite volume method. The influences of size and concentration of micro- and nanoparticles, shear forces, and turbulence on erosion behavior of fluid flow were studied. The model predictions are compared with the earlier studies and a good agreement is found. The results indicate that the erosion rate is directly dependent on particles' size and volume fraction as well as flow velocity. It has been observed that the maximum pressure has direct relationship with the particle volume fraction and velocity but has a reverse relationship with the particle diameter. It also has been noted that there is a threshold velocity as well as a threshold particle size, beyond which significant erosion effects kick in. The average friction factor is independent of the particle size and volume fraction at a given fluid velocity but increases with the increase of inlet velocities.

Numerical study of entropy generation due to coupled laminar and turbulent mixed convection and thermal radiation in an enclosure filled with a semitransparent medium.

The effect of radiation on laminar and turbulent mixed convection heat transfer of a semitransparent medium in a square enclosure was studied numerically using the Finite Volume Method. A structured mesh and the SIMPLE algorithm were utilized to model the governing equations. Turbulence and radiation were modeled with the RNG k-ε model and Discrete Ordinates (DO) model, respectively. For Richardson numbers ranging from 0.1 to 10, simulations were performed for Rayleigh numbers in laminar flow (104) and turbulent flow (108). The model predictions were validated against previous numerical studies and good agreement was observed. The simulated results indicate that for laminar and turbulent motion states, computing the radiation heat transfer significantly enhanced the Nusselt number (Nu) as well as the heat transfer coefficient. Higher Richardson numbers did not noticeably affect the average Nusselt number and corresponding heat transfer rate. Besides, as expected, the heat transfer rate for the turbulent flow regime surpassed that in the laminar regime. The simulations additionally demonstrated that for a constant Richardson number, computing the radiation heat transfer majorly affected the heat transfer structure in the enclosure; however, its impact on the fluid flow structure was negligible.

The effect of different doses of gonadorelin on ovarian follicle dynamics in river buffalo (Bubalus bubalis).

The objective of this study was to determine the response of the ovarian dominant follicle to the different doses of GnRH in river buffalo. The estrous cycle of 12 river bufflaloes was synchronized using norgestomet implant for 12 days in association with two injections of prostaglandin F2alpha analogue on Days 0 and 7 of implant insertion. On Day 6 or 7 of the ensuing cycle (Day 0 of the experiment), females received a norgestomet implant in conjunction with two prostaglandin injections on Days 0 and 1. On Day 6 of the experiment, females were randomly allocated into three groups. At this time, Group 1 and 2 females were given an i.m. injection of 50 or 100 microg Gonadorelin, respectively. Group 3 females did not receive any further treatment and were considered as control. All females were given prostaglandin on Day 12 and implants were removed on Day 13 of the experiment. The results revealed that in the control group, ovarian dominant follicle became persistent throughout the experiment; whereas, the persistent dominant follicle in all females belonging to Group 2 (100 microg GnRH) and one female in Group 1 (50 microg GnRH) ovulated within 48 h, subsequent with an emergence of a new follicular wave and an increase in plasma progesterone concentration within 72 and 96 h after GnRH injection, respectively. In conclusion, 100 microg of Gonadorelin seems to be the most effective dose to induce ovulation followed by an emergence of a new follicular wave in river buffalo.