A Thoroughgoing Design of a Rapid-cycle Microfluidic Droplet-based PCR Device to Amplify Rare DNA Strands

DNA is a molecule and assortment of fruitful information of organisms and a wide range of viruses. Polymerase chain reaction (PCR) is a process used to amplify DNA strands in order to generate millions of them and extract the applicable information. Although conventional methods for PCR are flourishing to a certain extent, they have such major drawbacks as contamination, high material consumption, and low-speed function. By the combination of PCR devices with the microfluidic approach and integrating them with droplet generation technology, the mentioned problems can be eliminated. In this study, a novel two-step rapid-cycle droplet-based PCR (dPCR) device, considering the design of microchannel and heat transfer system, has been presented. First, numerous studies have been conducted to select the proper droplet generator for the integration of the droplet generation with the PCR device. Then, with the careful attention to the requirements of a PCR device, the geometry of different zones of the PCR device has been, meticulously, designed. In the next and last step, the heat transfer system for the designed zones of the PCR device has been planned. Afterward, results are examined carefully which indicate that in a cycle of PCR, they are not any major discrepancies between the designed dPCR and the ideal one—the one that is intended to be created

Investigating the trend and severity of withdrawal symptoms in Methamphetamine users amongst homeless addicts

Background: Determining the trend and severity of withdrawal symptoms is considered as the first stage of addiction treatment. Objectives: Therefore, The purpose of this study was to investigate the trend and severity of withdrawal symptoms in methamphetamine (meth) addicts. Patients and Methods: This cross-sectional study was conducted on all the clients admitted to quit methamphetamine abuse in a residential treatment center for homeless addicts in Alborz province. According to the average daily intake, the clients were divided into two groups: mild and severe. To collect the data for this study; methamphetamine withdrawal symptoms assessment scale, Beck Depression Inventory (BDI) and a demographic information questionnaire were used. The analysis of variance (ANOVA) was done for repeated measures through the SPSS software version 16 and at a significance level of 0.05. Results: The findings showed that methamphetamine withdrawal symptoms including anxiety, abuse craving, and fatigue in the first 24 hours and the first, the second, and the third weeks as well as the symptoms of depression within three weeks after the withdrawal began to decline significantly (P < 0.0001). Following the analysis of variance (ANOVA) for repeated data and taking addiction severity index into account, it was observed that the difference between the two groups of mild and severe addicts was significant in terms of the trend and severity of methamphetamine withdrawal symptoms (P < 0.0001). Conclusions: The hardest stage to quit methamphetamine addiction was the first 24 hours after withdrawal with a downward trend; however, abuse craving especially in severe addicted group persisted even after the third week of withdrawal which could be a risk factor for recurrence and re-abuse. Thus, it was suggested that therapists were required to pay more attention to this issue in the treatment of this group of addicted individuals. © 2018, International Journal of High Risk Behaviors and Addiction

A thoroughgoing design of a rapid-cycle microfluidic droplet-based PCR device to amplify rare DNA strands

DNA is a molecule and assortment of fruitful information of organisms and a wide range of viruses. Polymerase chain reaction (PCR) is a process used to amplify DNA strands in order to generate millions of them and extract the applicable information. Although conventional methods for PCR are flourishing to a certain extent, they have such major drawbacks as contamination, high material consumption, and low-speed function. By the combination of PCR devices with the microfluidic approach and integrating them with droplet generation technology, the mentioned problems can be eliminated. In this study, a novel two-step rapid-cycle dropletbased PCR (dPCR) device, considering the design of microchannel and heat transfer system, has been presented. First, numerous studies have been conducted to select the proper droplet generator for the integration of the droplet generation with the PCR device. Then, with the careful attention to the requirements of a PCR device, the geometry of different zones of the PCR device has been, meticulously, designed. In the next and last step, the heat transfer system for the designed zones of the PCR device has been planned. Afterward, results are examined carefully which indicate that in a cycle of PCR, they are not any major discrepancies between the designed dPCR and the ideal one-the one that is intended to be created