Selective sequential recovery of zinc and copper from acid mine drainage

The observed imbalance between the unsustainable consumption of available natural metal resources and finite deposits makes the recovery and recycling of metals from metal-containing wastes an imperative. Here, ionic-liquid-based aqueous biphasic systems (IL-based ABSs) are proposed as an efficient alternative for selective metal recovery from real copper acid mine drainage (AMD) effluents. ABSs composed of different ILs and Na2SO4 were evaluated for Zn, Al, Cu, Co, and Ni extraction from both model solutions and AMD samples. It is shown that IL composed of thiocyanate anion ([SCN]−) presented a remarkable ability to extract metals from AMD through the formation of stable metal complexes. The addition of NaSCN to ABSs composed of tetrabutylammonium chloride ([N4444]Cl) allowed to mimic the use of [SCN]-based IL with additional advantages: tunable metal selectivity by the concentration of [SCN]− added to the ABS and a reduction in system cost and environmental impact. Furthermore, at the [SCN]− concentration range studied here, the formation of a hydrophobic salt composed of IL cations and metal complex anions is observed, which allows the selective extraction and recovery of transition metals in a single step. The IL-rich phase recyclability in three extraction cycles is demonstrated, showing the possibility to recover two times more Zn than with a single extraction cycle while using the same amount of IL and thiocyanate. Salt-rich phases were also recycled in a new IL-based ABS for the subsequent Cu extraction and recovery. These results allow the development of a sustainable process for the selective sequential recovery of transition metals from AMD.publishe

Assisted Reproduction: What factors interfere in the professional's decisions? Are single women an issue?

<p>Abstract</p> <p>Background</p> <p>With the development of medical technology, many countries around the world have been implementing ethical guidelines and laws regarding Medically Assisted Reproduction (MAR). A physician's reproductive decisions are not solely based on technical criteria but are also influenced by society values. Therefore, the aim of this study was to analyze the factors prioritized by MAR professionals when deciding on whether to accept to perform assisted reproduction and to show any existing cultural differences.</p> <p>Methods</p> <p>Cross-sectional study involving 224 healthcare professionals working with assisted reproduction in Brazil, Italy, Germany and Greece. Instrument used for data collection: a questionnaire, followed by the description of four special MAR cases (a single woman, a lesbian couple, an HIV discordant couple and gender selection) which included case-specific questions regarding the professionals' decision on whether to perform the requested procedure as well as the following factors: socio-demographic variables, moral and legal values as well as the technical aspects which influence decision-making.</p> <p>Results</p> <p>Only the case involving a single woman who wishes to have a child (without the intention of having a partner in the future) demonstrated significant differences. Therefore, the study was driven towards the results of this case specifically. The analyses we performed demonstrated that professionals holding a Master's Degree, those younger in age, female professionals, those having worked for less time in reproduction, those in private clinics and Brazilian health professionals all had a greater tendency to perform the procedure in that case. A multivariate analysis demonstrated that the reasons for the professional's decision to perform the procedure were the woman's right to gestate and the duty of MAR professionals to help her. The professionals who decided not to perform the procedure identified the woman's marital status and the child's right to a father as the reason to withhold treatment.</p> <p>Conclusion</p> <p>The study indicates differences among countries in the evaluation of the single woman case. It also discloses the undervaluation of bioethics committees and the need for a greater participation of healthcare professionals in debates on assisted reproduction laws.</p

Insulin resistance and carotid intima-media thickness mediate the association between resting-state heart rate variability and executive function: A path modelling study

Background: Research has linked high-frequency heart rate variability (HF-HRV) to cognitive function. The present study adopts a modern path modelling approach to understand potential causal pathways that may underpin this relationship. Methods: Here we examine the association between resting-state HF-HRV and executive function in a large sample of civil servants from Brazil (N = 8114) recruited for the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). HF-HRV was calculated from 10-min resting-state electrocardiograms. Executive function was assessed using the trail-making test (version B). Results and conclusions: Insulin resistance (a marker of type 2 diabetes mellitus) and carotid intima-media thickness (subclinical atherosclerosis) mediated the relationship between HRV and executive function in seriatim. A limitation of the present study is its cross-sectional design; therefore, conclusions must be confirmed in longitudinal study. Nevertheless, findings support that possibility that HRV provides a 'spark' that initiates a cascade of adverse downstream effects that subsequently leads to cognitive impairment.Fil: Kemp, Andrew H.. University of Sydney; Australia. Universidade de Sao Paulo; BrasilFil: Rodríguez López, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; Argentina. University of Sydney; Australia. Universidad Autónoma de Madrid; EspañaFil: Passos, Valeria M. A.. Universidade Federal de Minas Gerais; BrasilFil: Bittencourt, Marcio S.. Universidade de Sao Paulo; BrasilFil: Dantas, Eduardo M.. University of Vale do São Francisco; BrasilFil: Mill, José G.. Universidade Federal do Espírito Santo; BrasilFil: Ribeiro, Antonio L. P.. Universidade Federal de Minas Gerais; BrasilFil: Thayer, Julian F.. Ohio State University; Estados UnidosFil: Bensenor, Isabela M.. Universidade de Sao Paulo; BrasilFil: Lotufo, Paulo A.. Universidade de Sao Paulo; Brasi

Endometriose

Endometriosis is characterized by the dissemination of glands and endometrial stroma to ectopic sites in the uterine cavity and musculature. It is a contrasting disease that presents no association between clinical status and quantity of lesions. Some of the patients present asymptomatic, whereas others present diverse manifestation of clinical status characterized by pelvic pain, infertility, dysmenorrhea, and dyspareunia. The etiopathogeny of endometriosis is uncertain, and the most widely known hypotheses are related to celomic metaplasia, to transplantation, and to induction. The diagnosis of endometriosis is usually carried out through laparoscopy, in which case the identification of typical lesions confirms the diagnosis. Treatment for endometriosis includes induction of a pseudopregnancy state. There are many drugs that can be used to induce pregnancy, such as progestational hormones, derived forms of androgen, birth-control medication, and analogous forms of the gonadotropin-releasing hormone (GnRH). Endometriosis can also be surgically treated with a conservative procedure of cauterization and/or resection of the lesions. Cases of endometriosis that are more resistant or that occur in patients who are not worried about their fertility can be managed with more aggressive surgical procedures such as hysterectomy, for example. Infertility is treated with techniques of assisted reproduction in cases associated with anatomical factors. In all forms of treatment there is a relatively high incidence of recurrence and failure, in which case different therapeutic options should be employed.Endometriose é caracterizada pela presença de glândulas e estroma endometrial fora da cavidade e musculatura uterinas. É uma doença de contrastes, onde não há associação entre a intensidade do quadro clínico e a quantidade das lesões. Uma parcela das pacientes são assintomáticas, com a outra porção variando na apresentação do quadro clínico que é caracterizado por dor pélvica, infertilidade, dismenorréia e dispareunia. Não existe até o momento uma etiopatogenia definida para a endometriose e as teorias mais conhecidas envolvem a metaplasia celômica, os implantes ectópicos e a indução de células multipotenciais. O diagnóstico da endometriose normalmente é realizado através da laparoscopia, onde a identificação de lesões características firma o diagnóstico. O tratamento pressupõe um estado de pseudogestação. Há diversas medicações que produzem esse efeito como os progestágenos, os derivados androgênicos, os anticoncepcionais e os análogos do hormônio liberador de gonadotrofinas (GnRH). Outra forma de tratamento é o cirúrgico conservador onde há cauterização e/ou ressecção das lesões. Os casos mais resistentes ou onde não existe mais preocupação com fertilidade podem ser manejados com tratamentos cirúrgicos mais agressivos como a histerectomia. A infertilidade é tratada com técnicas de reprodução assistida quando há fator anatômico associado. Em todas as formas de tratamento há um índice relativamente alto de recorrências e falhas a determinados tipos de tratamento, que devem ser manejados com outras opções terapêuticas.

Infertilidade masculina

Between 10 to 15% of couples can be unsuccessful at trying to have children after one year of unprotected sexual intercourse. About 50% of cases of infertility are related to male infertility. The cause of male infertility, in turn, is frequently associated with sperm alterations. Traditionally, male infertility has been considered as a condition that is difficult to be treated. New studies in the field of Genetics have presented findings of deletion or mutation in groups of genes that could have a causal relation to infertility in male patients. Most advancements in the treatment of male infertility are in the area of assisted reproduction, which, in turn, has developed following the progress in technologies of gamete micromanipulation. Our study is aimed at assessing causes of, and treatment for male infertility. Entre 10 a 15% dos casais falham em ter filhos após um ano de intercursos sexuais não protegidos. Cerca de 50% das causas de infertilidade são de origem masculina. Como causa simples de infertilidade, alterações espermáticas são a condição mais freqüente. A infertilidade de causa masculina foi tradicionalmente considerada como uma condição de difícil tratamento. Novos estudos na área da genética têm encontrado deleções ou mutações em grupos de genes que poderiam explicar a infertilidade nesses pacientes. A maior parte dos avanços no tratamento destes casos reside nas técnicas de reprodução assistida, que tiveram seu maior avanço após o desenvolvimento da tecnologia da micromanipulação de gametas. O presente trabalho faz uma análise de causas e de tratamentos para dar solução à infertilidade masculina.