Microchips and their significance in isolation of circulating tumor cells and monitoring of cancers

In micro-fluid systems, fluids are injected into extremely narrow polymer channels in small amounts such as micro-, nano-, or pico-liter scales. These channels themselves are embedded on tiny chips. Various specialized structures in the chips including pumps, valves, and channels allow the chips to accept different types of fluids to be entered the channel and along with flowing through the channels, exert their effects in the framework of different reactions. The chips are generally crystal, silicon, or elastomer in texture. These highly organized structures are equipped with discharging channels through which products as well as wastes of the reactions are secreted out. A particular advantage regarding the use of fluids in micro-scales over macro-scales lies in the fact that these fluids are much better processed in the chips when they applied as micro-scales. When the laboratory is miniaturized as a microchip and solutions are injected on a micro-scale, this combination makes a specialized construction referred to as "lab-on-chip". Taken together, micro-fluids are among the novel technologies which further than declining the costs; enhancing the test repeatability, sensitivity, accuracy, and speed; are emerged as widespread technology in laboratory diagnosis. They can be utilized for monitoring a wide spectrum of biological disorders including different types of cancers. When these microchips are used for cancer monitoring, circulatory tumor cells play a fundamental role

Diameter-dependent elastic properties of carbon nanotube-polymer composites: Emergence of size effects from atomistic-scale simulations

We propose a computational procedure to assess size effects in nonfunctionalized single-walled carbon nanotube (CNT)-polymer composites. The procedure upscales results obtained with atomistic simulations on a composite unit cell with one CNT to an equivalent continuum composite model with a large number of CNTs. Molecular dynamics simulations demonstrate the formation of an ordered layer of polymer matrix surrounding the nanotube. This layer, known as the interphase, plays a central role in the overall mechanical response of the composite. Due to poor load transfer from the matrix to the CNT, the reinforcement effect attributed to the CNT is negligible; hence the interphase is regarded as the only reinforcement phase in the composite. Consequently, the mechanical properties of the interface and the CNT are not derived since their contribution to the elastic response of the composite is negligible. To derive the elastic properties of the interphase, we employ an intermediate continuum micromechanical model consisting of only the polymer matrix and a three-dimensional fiber representing the interphase. The Young’s modulus and Poisson’s ratio of the equivalent fiber, and therefore of the interphase, are identified through an optimization procedure based on the comparison between results from atomistic simulations and those obtained from an isogeometric analysis of the intermediate micromechanical model. Finally, the embedded reinforcement method is employed to determine the macroscopic elastic properties of a representative volume element of a composite with various fiber volume fractions and distributions. We then investigate the role of the CNT diameter on the elastic response of a CNT polymer composite; our simulations predict a size effect on the composite elastic properties, clearly related to the interphase volume fraction

Short view of leukemia diagnosis and treatment in Iran

Background: Early diagnosis and treatment of leukemia patients remains a fundamental aim in clinical oncology, especially in developing country. Present study highlights the basic requirements of these patients in Iran. Better understanding of these issues may lead to improve the healthcare standards toward leukemia diagnosis and treatment. Methods: This descriptive study included 101 specialists in hematology-oncology and pathology serving in oncology centers. The participants were then asked to fill out a standard questionnaire on the issues around diagnosis and treatment of blood malignancies. Results: According to specialists, unfair distribution of facilities across the country, delayed diagnosis of disease, absence of psychological support for patients, and insufficient financial support were the main reasons of inappropriate diagnosis and treatment in leukemia patients. Conclusions: Our results show that making an amendment to health policies by preparing well-equipped medical centers in all provinces, improving the morale of patients through consultation during the process of treatment, and above all, subsiding leukemia patients' financial problems will promote the health standard regarding the leukemia diagnosis and treatment in Iran. © 2015, Tehran University of Medical Sciences (TUMS). All rights reserved

The Study on Relation of Human Papillomavirus High Risk Types with Bladder Transitional Cell Carcinoma

En este programa se hablará sobre las telecomunicaciones, se les contará qué es, como mueve al mundo actualmente y como la Universidad Militar Nueva Granada se prepara para formar a los mejores profesionales en este campo

Detection of ISPa1328 and ISPpu21, Two Novel Insertion Sequences in the OprD Porin and bla_IMP-1 Gene Among Metallo-Beta-Lactamase-Producing Pseudomonas aeruginosa Isolated From Burn Patients

Background: Carbapenemes are a good choice for treatment of infections caused by multidrug resistant Pseudomonads aeruginosa. The emergence of carbapenem resistance has become a major problem in treatment of this organism especially among immunocompromised patients including burn patients. Objectives: The aim of this study was to investigate carbapenem-resistance mechanisms among burn patients in Tehran, Iran, during 2014 - 2015. Methods: The antibiotic resistance phenotypic test was accomplished by the Kirby Bauer disk diffusion method. The phenotypic investigation of metallo-beta-lactamase (MBL) producers was evaluated by the combined disk diffusion test (CDDT) method. The prevalence of MBL genes, including blaIMP-1 and blaVIM-1 was evaluated by polymerase chain reaction (PCR) and sequencing methods. Amplification of oprD was performed by PCR and the results of sequencing were aligned with wild-type P. aeruginosa strain PAO1. Results: A total of 100 P. aeruginosa were investigated, of which, 95 were resistance to imipenem. Out Of 95 imipenem resistant isolates,, 81 (85.2%) were MBL producers. Among all isolates, 13 strains carried the blaIMP-1 gene, whereas all of the strains were negative for the blaVIM-1 gene. Amplification of OprD porin was performed for all 100 P. aeruginosa strains. Two insertion sequences (ISs) including ISPpu21 and ISPa1328 were detected in PCR products of OprD gene, that were larger than expected. Conclusions: The prevalence of β-lactamase-producing isolates and their isolation from life-threatening infections in burn patients is increasing at an alarming rate worldwide. Also, we have identified two novel IS elements, ISPa1328 and ISPpu21, in P. aeruginosa isolates from hospitals in Tehran, Iran. In most of the isolates, insertional inactivation of oprD by ISPa1328 and ISPpu21 were associated with carbapenem resistance