Adsorptive removal of lead from aqueous solutions by amine–functionalized magMCM-41 as a low–cost nanocomposite prepared from rice husk: Modeling and optimization by response surface methodology

Amorphous silica that was extracted from rice husk was used to synthesize the magMCM-41 mesoporous silica. This was then functionalized by the APTMS group in order to produce NH₂-magMCM-41 as a novel and low–cost adsorbent. The XRD, VSM, N₂ adsorption–desorption, FT–IR, TGA, SEM and TEM analyses were utilized to characterize the produced materials. In order to optimize the adsorption of the Pb(II) ions, the RSM (response surface methodology) was applied by using the synthesized adsorbent in aqueous solutions. A rotatable CCD (central composite design) was adopted to carry out the experiments and RSM was used to analyze them. Three independent factors namely, initial solution pH (3–7), adsorbent dosage (0.1–2 g L^?1), and initial Pb(II) concentration (15–150 mg L^?1) were used to investigate the removal procedure. According to the obtained results, the initial solution pH of 5.22, adsorbent dosage of 0.1 g L^?1, and initial Pb(II) concentration of 150 mg L^?1 were considered as the optimum conditions with 64.32% removal of Pb(II) and an adsorption capacity of 540.64 mg g^?1. The maximum removal efficiency of Pb(II) ions was found to be 96.76%. The Sips isotherm model represents a better correlation with equilibrium data. It was reported by the kinetic study that data taken from the experiments fitted better to the pseudo–second–order model compared to the pseudo–first–order and intraparticle diffusion models. Finally, according to the thermodynamic study, the removal process strongly depends on temperature, which indicates an exothermic behavior and spontaneous nature of the adsorption.     

Sexual compatibility among Iranian couples: a qualitative study

Sexual compatibility increases the stability of marriage and partners’ relationships and decreases sexually transmitted diseases. This qualitative study using a content analysis approach was conducted with 36 married men and women. Interviews were conducted for data collection. As the main theme of this study, “couple's sexual companionship” emerged as the main theme of sexual compatibility, that means couples’ participation for fulfilling each other sexual needs and solving problems arising from sexual discrepancies based on sexual understandings, sexual agreements and interests for continuing the sexual relationship with the aim of mutual sexual satisfaction. Sexual compatibility did not necessarily mean similarities, as during the marital life sexual discrepancies were inevitable. However, compatible couples encountered such a situation based on understandings, agreement and love. Active participation in sexual relationships, forgiveness and consideration, no huffing, mutual respect, flexibility and an occasional use of non-penetrative sexual relationships, sexual conversation with spouses, patience and development of the sexual relationship were the prominent feature of sexually compatible couples.     

Cognitive rehabilitation for individuals with opioid use disorder: A randomized controlled trial*

Aim: To examine the efficacy of cognitive rehabilitation treatment (CRT) for people with opioid use disorder who were recruited into a methadone maintenance treatment (MMT) programme.

Method: 120 male subjects were randomly assigned to (1) MMT plus CRT in two months or (2) MMT plus a control intervention. Subjects were assessed at the beginning, mid-point and post-intervention as well as at 1-, 3- and 6-month follow-up time points.

Results: Analysis with repeated measure ANOVA showed that the CRT group performed significantly better in tests of learning, switching, processing speed, working memory and memory span. Moreover, the CRT group had significantly lower opiate use over the control group during 3-months follow-up. Analysis including only those with a history of methamphetamine use showed that the CRT group had significantly lower amphetamine use. No group differences were observed for treatment retention.

Conclusions: Our findings provide evidence that adding CRT as an adjunct intervention to MMT can improve cognitive performance as well as abstinence from both opiates and stimulants.     

Survivin as a diagnostic and therapeutic marker for thyroid cancer

Thyroid cancer (TC) is known as the most prevalent form of endocrine malignancy. With regard to high heterogeneity of the nodules, problem of discriminating between benign and malignant ones in terms of pathological characteristics, as well as lack of appropriate molecular markers; significant efforts are being made to identify molecular markers that able to detect tumorous lesions. Survivin, the newest member of the family of proteins inhibiting cell apoptosis, has been recently considered as a novel molecule marker for cancer. Studies on TC have also demonstrated distinctive expression of survivin and its splice variants in cancer cells compared to normal ones. Therefore, detection of survivin expression and its new splice variants can be utilized to identify tumor nodules and distinguish them from non-cancerous ones, along with other routine laboratory methods.     

An Introduction to the Residency Application Process

Emergency medicine (EM) is a swiftly developing yet still relatively young discipline. We are going to present in the Medical Student Forum section of the Journal of Emergency Medicine several article series covering the key topics that medical students interested in emergency medicine will find helpful. This article introduces the topics that will be tackled in the first compilation of articles dealing with the residency application process.