A simple, fast and inexpensive approach to quantify low concentrations of iron in biodiesel by voltammetry after extraction induced by microemulsion breaking.

An alternative approach to assay iron (Fe) in biodiesel by differential pulse adsorptive cathodic stripping voltammetry (DPAdCSV) is presented herein. The sample treatment involved a simple, rapid, but effective extraction of Fe from biodiesel into an aqueous phase after microemulsion (ME) breaking. Then, Fe was determined as the complex Fe(III)-PAN (1-(2-pyridylazo)-2-naphthol) on a glassy carbon electrode (GCE) in the presence of bismuth (Bi(III)). The extraction induced by microemulsion breaking (EIMB) was achieved by adding 0.80 mL of ultrapure water into a water-in-oil ME containing 7.00 mL biodiesel, 2.70 mL n-propanol and 0.30 mL of 0.25 mol L-1 HNO3 solution. No deliberate addition of surfactant was necessary to form and maintain the ME. The EIMB resulted in a 1.30 mL lower aqueous phase extract (APhEx) and an upper oily phase. DP voltammograms were recorded with a portable potentiostat, showing the potentiality of carrying out the determination out of a central laboratory. Another feature was the non-necessity of deaerating the solution to eliminate the dissolved O2. The limits of detection (LOD) and quantification (LOQ) were 1.7 µg L-1 (140 mg kg-1) and 5.5 µg L-1 (455 mg kg-1), respectively. The accuracy of the method was evaluated by recovery assays of spiked samples, by analyzing a standard reference material and by comparisons with high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS).

How to overcome the difficulty in assaying Ni in biodiesel samples? Extraction induced by microemulsion breaking and square wave adsorptive stripping voltammetry could be the answer.

Herein, a simple, green, and relatively inexpensive approach to determine nickel (Ni) in biodiesel samples by square wave adsorptive cathodic stripping voltammetry (SWAdCSV) is presented. A method based on the accumulation of Ni as Ni(II)-dimethylglyoxime (Ni(II)(HDMG)2) on the glassy carbon electrode was carried out in a solution containing the aqueous phase extract (APhEx) obtained from an extraction induced by microemulsion breaking (EIMB), which was achieved by adding a few microliters of ultrapure water to a microemulsion composed of biodiesel, n-propanol and a diluted HNO3 solution. The LOD and LOQ were 0.2 µg L-1 and 0.8 µg L-1, respectively, and the accuracy was evaluated by recovery assays of spiked samples and by analyzing a standard reference material. Results obtained from a comparative method (HR-CS GF AAS) were also used for this evaluation. The method was applied to biodiesel samples produced from different feedstocks. To the best of the authors knowledge, it is the first time that: 1) Ni in biodiesel is determined by a voltammetric method; 2) EIMB is applied to extract Ni from this matrix and 3) this type of sample preparation method is used with adsorptive stripping voltammetry.

Comparison of low back mobility and stability exercises from Pilates in non-specific low back pain: A study protocol of a randomized controlled trial.

BACKGROUND: There is some evidence in the literature about the effectiveness of the Pilates methods in the low back pain. Moreover, Pilates focus on exercises that empathizes the stability and/or mobility of the spine. Therefore, it is discussed in the literature whether higher levels of stability or mobility of the lumbar spine generates better results, both in performance and rehabilitation for low back pain. OBJECTIVES: Compare the effects of the low back mobility and stability exercises from Pilates Method on low back pain, disability and movement functionality in individuals with non-specific chronic low back pain. METHODS: 28 participants will be randomized into two exercise protocol from Pilates methods, one focusing on low back stability and other on low back mobility. Low back pain (visual analogic scale), low back disability (Oswestry) and movement functionality (7 functional movement tasks) will be evaluated before and after 10 sessions of Pilates exercise by the same trained assessor. A mixed designed ANOVA with two factors will be used. This study is the first to compare these outcomes for chronic low back pain participants with two exercises protocol focusing on low back mobility and stability and the results will evaluate what to prioritize with Pilates exercises to give better results for that population.

The subclassification of papillary renal cell carcinoma does not affect oncological outcomes after nephron sparing surgery.

OBJECTIVES: To evaluate the oncological outcomes of papillary renal cell carcinoma (pRCC) following nephron sparing surgery (NSS) and to determine whether the subclassification type of pRCC could be a prognostic factor for recurrence, progression, and specific death. MATERIALS AND METHODS: An international multicentre retrospective study involving 19 institutions and the French network for research on kidney cancer was conducted after IRB approval. We analyzed data of all patients with pRCC who were treated by NSS between 2004 and 2014. RESULTS: We included 486 patients. Tumors were type 1 pRCC in 369 (76 %) cases and type 2 pRCC in 117 (24 %) cases. After a mean follow-up of 35 (1-120) months, 8 (1.6 %) patients experienced a local recurrence, 12 (1.5 %) had a metastatic progression, 24 (4.9 %) died, and 7 (1.4 %) died from cancer. Patients with type I pRCC had more grade II (66.3 vs. 46.1 %; p < 0.001) and less grade III (20 vs. 41 %; p < 0.001) tumors. Three-year estimated cancer-free survival (CFS) rate for type 1 pRCC was 96.5 % and for type 2 pRCC was 95.1 % (p = 0.894), respectively. Three-year estimated cancer-specific survival rate for type 1 pRCC was 98.4 % and for type 2 pRCC was 97.3 % (p = 0.947), respectively. Tumor stage superior to pT1 was the only prognostic factor for CFS (HR 3.5; p = 0.03). CONCLUSION: Histological subtyping of pRCC has no impact on oncologic outcomes after nephron sparing surgery. In this selected population of pRCC tumors, we found that tumor stage is the only prognostic factor for cancer-free survival.

Estesioneuroblastoma: relatos de casos e revisão de literatura / Esthesioneuroblastoma: Case Reports and Literature Review

O estesioneuroblastoma (ENB) é uma neoplasia rara que atinge o neuroepitélio olfativo, comumente invadindo os seios paranasais, a base do crânio e a região orbitária. Apresenta metástase em 10 a 30 % dos casos. Distribui-se de forma bimodal para a idade, principalmente dos 11 aos 20 anos e dos 51 aos 60 anos, sem influência do sexo e raça do indivíduo. A ínfima quantidade de casos relatados resulta em dúvidas quanto ao melhor tratamento a ser dispensado ao paciente. Relatamos três casos, todos Kadish C, tornando o tratamento e o prognóstico um desafio à prática neurocirúrgica.

The esthesioneuroblastoma (ENB) is a rare neoplasm that affects the olfactory neuroepithelium, commonly invading the paranasal sinuses, skull base and the orbital region. Shows metastasis in 10% to 30% of cases. Distributed in a bimodal shape for the age, from 11 to 20 years and 51 to 60 years especially, with no influence of gender and race of the individual. The tiny amount of reported cases result in doubt about the best treatment to be dispensed to the patient. We report three cases, all Kadish C, making treatment and prognosis a challenge to neurosurgery.

Mudança demográfica e a dinâmica dos homicídios no Estado de São Paulo / Age structure explaining a large shift in homicides: the case of the state of São Paulo

Neste artigo, estima-se a contribuição da mudança na estrutura etária para a alteração nas taxas de homicídio no Estado de São Paulo entre 1991 e 2005. Para isso, usam-se tanto as variações puras ao longo do tempo como as diferenças entre cidades na dinâmica demográfica e no número de homicídios.