Advancing forensic research: An examination of compositional data analysis with an application on petrol fraud detection.

In recent years, numerous studies have examined the chemical compounds of petrol and petrol data for forensic research. Standard quantitative methods often assume that the variables or compounds do not have compositional constraints or are not part of a constrained whole, operating within an Euclidean vector space. However, chemical compounds are typically part of a whole, and the appropriate vector space for their analysis is the simplex. Biased and arbitrary results result when statistical analysis are applied on such data without proper pre-processing of such data. Compositional analysis of data has not yet been considered in forensic science. Therefore, we compare classical statistical analysis as applied in forensic research and the new proposed paradigm of compositional data analysis (CoDa). It is demonstrated how such analysis improves the analysis in petrol and forensic science. Our study shows how principal component analysis (PCA) and classification results are affected by the preprocessing steps performed on the raw data. Our results indicate that results from a log ratio analysis provides a better separation between subgroups of the data and leads to an easier interpretation of the results. In addition, with a compositional analysis a higher classification accuracy is obtained. Even a non-linear classification method - in our case a random forest - was shown to perform poorly when applied without using compositional methods. Moreover, normalization of samples due to laboratory/unit-of-measurement effects is no longer necessary, since the composition of an observation is in compositional thinking equivalent to a multiple of it, because the used (log) ratios on raw and log ratio transformed data are equal. Petrol data from different petrol stations in Brazil are used for the demonstration. This data is highly susceptible to counterfeit petrol. Forensic analysis of its chemical elements requires non-biased statistical analysis designed for compositional data to detect fraud. Based on these results, we recommend the use of compositional data methods for gasoline and petrol chemical element analysis and gasoline product characterization, authentication and fraud detection in forensic sciences.

Carcinoma basocelular en el Área Sur de Salud de Tenerife. Características clínico-patológicas fundamentales y estado de los bordes tras exéresis / Basal Cell Carcinoma in the Southern Health Area of Tenerife. Key Clinical and Pathological Factors and Margin Status After Excision

Antecedentes y objetivo El tratamiento de elección inicial del carcinoma basocelular (CBC) es la escisión quirúrgica. Esta debería ser completa para reducir el riesgo de recidiva. Nuestro objetivo es conocer las características de los CBC en nuestra área de salud, el porcentaje de márgenes afectos, y los factores de riesgo para una resección quirúrgica incompleta. Material y métodos Estudio observacional retrospectivo de los CBC intervenidos en el Área de Salud del Hospital Universitario Nuestra Señora de Candelaria entre el 1 de enero de 2014 y el 31 de diciembre de 2014. Recogemos datos demográficos, clínicos e histológicos, servicio responsable, abordaje quirúrgico y estado de los márgenes. Resultados Se diagnosticaron 966 CBC correspondientes a 776 pacientes, siendo el 9% biopsias, el 89% escisiones y el 2% rebanados. La mediana de edad fue de 71 años y el 52% eran hombres. La localización más frecuente fue la cara (59,1%). Se analizaron los márgenes quirúrgicos en 506 CBC. El 17% presentó afectación de márgenes. El porcentaje de márgenes afectos fue significativamente mayor en los tumores de la cara (22% cara vs. 10% otra localización) y en los de subtipo histológico de alto riesgo (OMS) (25% subtipo de alto riesgo vs. 15% bajo riesgo). Conclusiones Las características de nuestros pacientes con CBC se asemejan a las descritas previamente. La localización facial y el subtipo histológico son factores de riesgo para la resección incompleta del CBC. Por lo tanto, el abordaje quirúrgico inicial de los CBC con estas características ha de planearse de forma cuidadosa (AU)

Background and objective Surgical excision is the treatment of choice for basal cell carcinoma (BCC). Complete excision with clear margins is important for reducing the risk of recurrence. The aims of this study were to describe the characteristics of BCCs in our health care area, calculate the percentage of positive margins after surgical excision, and determine the risk factors for incomplete excision. Material and methods Retrospective observational study of BCCs that were surgically removed at Hospital Universitario Nuestra Señora de Candelaria, in Santa Cruz de Tenerife, Spain, between January 1, 2014 and December 31, 2014. Information was collected on demographic, clinical, and histologic variables, surgical approach, margin status, and the department responsible. Results In total, 966 BCCs were diagnosed in 776 patients. Nine percent of tumors with complete data were biopsied, 89% were surgically excised, and 2% were removed by shave excision. The median age of patients with excised tumors was 71 years and 52% were men. BCCs were most often located on the face (59.1%). Surgical margins were analyzed in 506 cases, 17% of which had positive margins. Incomplete excision was significantly more common in tumors located on the face (22% vs. 10% for other locations) and in high-risk subtypes according to the World Health Organization classification (25% vs. 15% for low-risk subtypes). Conclusions The characteristics of BCCs in our health care area are similar to those described elsewhere. Facial location and histologic subtype are risk factors for incomplete excision. Careful surgical planning is therefore important in the initial management of BCCs with these characteristics (AU)

[Translated article] Basal Cell Carcinoma in the Southern Health Area of Tenerife: Key Clinical and Pathological Factors and Margin Status After Excision / Carcinoma basocelular en el Área Sur de Salud de Tenerife: Características clínico-patológicas fundamentales y estado de los bordes tras exéresis

Background and objective Surgical excision is the treatment of choice for basal cell carcinoma (BCC). Complete excision with clear margins is important for reducing the risk of recurrence. The aims of this study were to describe the characteristics of BCCs in our health care area, calculate the percentage of positive margins after surgical excision, and determine the risk factors for incomplete excision. Material and methods Retrospective observational study of BCCs that were surgically removed at Hospital Universitario Nuestra Señora de Candelaria, in Santa Cruz de Tenerife, Spain, between January 1, 2014 and December 31, 2014. Information was collected on demographic, clinical, and histologic variables, surgical approach, margin status, and the department responsible. Results In total, 966 BCCs were diagnosed in 776 patients. Nine percent of tumors with complete data were biopsied, 89% were surgically excised, and 2% were removed by shave excision. The median age of patients with excised tumors was 71 years and 52% were men. BCCs were most often located on the face (59.1%). Surgical margins were analyzed in 506 cases, 17% of which had positive margins. Incomplete excision was significantly more common in tumors located on the face (22% vs. 10% for other locations) and in high-risk subtypes according to the World Health Organization classification (25% vs. 15% for low-risk subtypes). Conclusions The characteristics of BCCs in our health care area are similar to those described elsewhere. Facial location and histologic subtype are risk factors for incomplete excision. Careful surgical planning is therefore important in the initial management of BCCs with these characteristics (AU)

Antecedentes y objetivo El tratamiento de elección inicial del carcinoma basocelular (CBC) es la escisión quirúrgica. Esta debería ser completa para reducir el riesgo de recidiva. Nuestro objetivo es conocer las características de los CBC en nuestra área de salud, el porcentaje de márgenes afectos, y los factores de riesgo para una resección quirúrgica incompleta. Material y métodos Estudio observacional retrospectivo de los CBC intervenidos en el Área de Salud del Hospital Universitario Nuestra Señora de Candelaria entre el 1 de enero de 2014 y el 31 de diciembre de 2014. Recogemos datos demográficos, clínicos e histológicos, servicio responsable, abordaje quirúrgico y estado de los márgenes. Resultados Se diagnosticaron 966 CBC correspondientes a 776 pacientes, siendo el 9% biopsias, el 89% escisiones y el 2% rebanados. La mediana de edad fue de 71 años y el 52% eran hombres. La localización más frecuente fue la cara (59,1%). Se analizaron los márgenes quirúrgicos en 506 CBC. El 17% presentó afectación de márgenes. El porcentaje de márgenes afectos fue significativamente mayor en los tumores de la cara (22% cara vs. 10% otra localización) y en los de subtipo histológico de alto riesgo (OMS) (25% subtipo de alto riesgo vs. 15% bajo riesgo). Conclusiones Las características de nuestros pacientes con CBC se asemejan a las descritas previamente. La localización facial y el subtipo histológico son factores de riesgo para la resección incompleta del CBC. Por lo tanto, el abordaje quirúrgico inicial de los CBC con estas características ha de planearse de forma cuidadosa (AU)

Basal Cell Carcinoma in the Southern Health Area of Tenerife. Key Clinical and Pathological Factors and Margin Status After Excision. / Carcinoma basocelular en el Área Sur de Salud de Tenerife. Características clínico-patológicas fundamentales y estado de los bordes tras exéresis.

BACKGROUND AND OBJECTIVE: Surgical excision is the treatment of choice for basal cell carcinoma (BCC). Complete excision with clear margins is important for reducing the risk of recurrence. The aims of this study were to describe the characteristics of BCCs in our health care area, calculate the percentage of positive margins after surgical excision, and determine the risk factors for incomplete excision. MATERIAL AND METHODS: Retrospective observational study of BCCs that were surgically removed at Hospital Universitario Nuestra Señora de Candelaria, in Santa Cruz de Tenerife, Spain, between January 1, 2014 and December 31, 2014. Information was collected on demographic, clinical, and histologic variables, surgical approach, margin status, and the department responsible. RESULTS: In total, 966 BCCs were diagnosed in 776 patients. Nine percent of tumors with complete data were biopsied, 89% were surgically excised, and 2% were removed by shave excision. The median age of patients with excised tumors was 71 years and 52% were men. BCCs were most often located on the face (59.1%). Surgical margins were analyzed in 506 cases, 17% of which had positive margins. Incomplete excision was significantly more common in tumors located on the face (22% vs. 10% for other locations) and in high-risk subtypes according to the World Health Organization classification (25% vs. 15% for low-risk subtypes). CONCLUSIONS: The characteristics of BCCs in our health care area are similar to those described elsewhere. Facial location and histologic subtype are risk factors for incomplete excision. Careful surgical planning is therefore important in the initial management of BCCs with these characteristics.

KI effects on corrosion inhibition for 1018 steel in acid media using Medicago sativa.

Medicago sativa (M. sativa) extract is a safe and eco-friendly corrosion inhibitor of 1018 steel in acid media. The inhibitor reached a maximum efficiency of 85% by using 500 ppm. In this work, we study the use of KI as an add-on to increase the inhibition efficiency of M. sativa, as well as making the natural inhibitor competitive with the commercial ones. We evaluated the effect of halide ions through the variation of different concentrations of KI and its synergy with the extract of M. sativa as a corrosion inhibitor of carbon steel in 0.5 M sulfuric acid and at different temperatures. The results were obtained through electrochemical techniques such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) curves, and weight loss gravimetric technique. It was found that halide ions increase the inhibition efficiency of M. sativa from 85 to 95% when 5 mM concentration of KI was used. The efficiency of the inhibition increases proportionally with the immersion time but reduces when the temperature increases. The addition of iodide ions (I-) revealed that it exerts a synergistic effect on the inhibition of corrosion with the extract of M. sativa. However, when studying the metal surface using a scanning electron microscope, pitting corrosion was found.

Experimental and Theoretical Studies of α-Linolenic Acid as Green Corrosion Inhibitor for Carbon Steel in 0.5 M Sulfuric Acid.

A component of Salvia hispanica, α-linolenic acid, has been evaluated as a green corrosion inhibitor for 1018 carbon steel in 0.5 M sulfuric acid using weight loss tests, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) measurements. Theoretical calculations using Density Functional Theory (DFT) were used also. The results have shown that this compound is a good corrosion inhibitor, with an efficiency which increased with an increase in its concentration up to 600 ppm, but it decreased with a further increase in the concentration. α-linolenic acid formed protective corrosion products layer because it was chemically adsorbed onto the steel surface according to a Langmuir type of adsorption isotherms. Polarization curves have shown that α-linolenic acid is a good, mixed type of inhibitor with a predominant effect on the cathodic hydrogen evolution reactions. EIS measurements indicated a charge transfer-controlled corrosion process. DFT calculations indicated that α-linolenic acid was more efficient in an acidic environment than in a neutral one because has a high tendency to donate electrons and can be easily protonated. In addition to this, it had the highest EHUMO value, the best chemical reactivity, the greatest tendency to transfer electrons and a greater facility of modifying its electronic configuration in the presence of carbon steel specimens according to its chemical hardness value.

Use of a Gemini-Surfactant Synthesized from the Mango Seed Oil as a CO2-Corrosion Inhibitor for X-120 Steel.

A gemini surfactant imidazoline type, namely N-(3-(2-fatty-4,5-dihydro-1H-imidazol-1-yl) propyl) fatty amide, has been obtained from the fatty acids contained in the mango seed and used as a CO2 corrosion inhibitor for API X-120 pipeline steel. Employed techniques involved potentiodynamic polarization curves, linear polarization resistance, and electrochemical impedance spectroscopy. These tests were supported by detailed scanning electronic microscopy (SEM) and Raman spectroscopy studies. It was found that obtained gemini surfactant greatly decreases the steel corrosion rate by retarding both anodic and cathodic electrochemical reactions, with an efficiency that increases with an increase in its concentration. Gemini surfactant inhibits the corrosion of steel by the adsorption mechanism, and it is adsorbed on to the steel surface according to a Langmuir model in a chemical type of adsorption. SEM and Raman results shown the presence of the inhibitor on the steel surface.

Iron oxide-mediated photo-Fenton catalysis in the inactivation of enteric bacteria present in wastewater effluents at neutral pH.

The pressure on natural water resources associated with increasing water scarcity highlights the value of using reclaimed water through the development of efficient and environmentally friendly treatment technologies. In this work, the use of magnetic nanoparticles in photo-Fenton catalysis for water disinfection was considered to inactivate natural enteric bacteria present in municipal wastewater effluents under white light and neutral pH. The most recommended ranges were evaluated in key variables such as the loading and composition of nanoparticles (NPs), hydrogen peroxide (H2O2) concentration, the light source (UV and visible) and treatment time were evaluated in wastewater disinfection expressed in terms of total coliforms and Escherichia coli colony forming units (CFU). The magnetic separation of NPs allowed the disinfection process to be carried out in different cycles, facilitating the recovery of the nanocatalyst and avoiding its discharge with the treated effluent.

Rare Earth-Based Compounds as Inhibitors of Hot-Corrosion Induced by Vanadium Salts.

In this study, the performance evaluation of lanthanum compounds as corrosion inhibitors of vanadium salts was performed. The inhibitors tested were lanthanum acetate and La2O3. The performance of the inhibitors was tested using sodium metavanadate (NaVO3) as a corrosive medium at 700, 800, and 900 °C. The corrosion inhibitory effect was evaluated on the corrosion process of 304H stainless steel. The corrosion rate of the steel was determined by the mass loss technique after 100 h of immersion in the corrosive salt with and without the addition of the corrosion inhibitor. The results show that lanthanum compounds act as corrosion inhibitors of vanadium salts. The inhibitory effect increases by increasing the concentration and tends to decrease when increasing the test temperature. Lanthanum compounds act as excellent corrosion inhibitors due to their ability to stabilize vanadium cations. Vanadium is stabilized by forming a new compound, lanthanum vanadate (LaVO4), with a melting point much higher than the compounds formed when Mg or Ni compounds are used as corrosion inhibitors.

Simultaneous determination of V, Ni and Fe in fuel fly ash using solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry.

A green and simple method has been proposed in this work for the simultaneous determination of V, Ni and Fe in fuel ash samples by solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry (SS HR CS GFAAS). The application of fast programs in combination with direct solid sampling allows eliminating pretreatment steps, involving minimal manipulation of sample. Iridium treated platforms were applied throughout the present study, enabling the use of aqueous standards for calibration. Correlation coefficients for the calibration curves were typically better than 0.9931. The concentrations found in the fuel ash samples analysed ranged from 0.66% to 4.2% for V, 0.23-0.7% for Ni and 0.10-0.60% for Fe. Precision (%RSD) were 5.2%, 10.0% and 9.8% for V, Ni and Fe, respectively, obtained as the average of the %RSD of six replicates of each fuel ash sample. The optimum conditions established were applied to the determination of the target analytes in fuel ash samples. In order to test the accuracy and applicability of the proposed method in the analysis of samples, five ash samples from the combustion of fuel in power stations, were analysed. The method accuracy was evaluated by comparing the results obtained using the proposed method with the results obtained by ICP OES previous acid digestion. The results showed good agreement between them. The goal of this work has been to develop a fast and simple methodology that permits the use of aqueous standards for straightforward calibration and the simultaneous determination of V, Ni and Fe in fuel ash samples by direct SS HR CS GFAAS.

Modelling of Behavior for Inhibition Corrosion of Bronze Using Artificial Neural Network (ANN).

In this work, three models based on Artificial Neural Network (ANN) were developed to describe the behavior for the inhibition corrosion of bronze in 3.5% NaCl + 0.1 M Na2SO4, using the experimental data of Electrochemical Impedance Spectroscopy (EIS). The database was divided into training, validation, and test sets randomly. The parameters process used as the inputs of the ANN models were frequency, temperature, and inhibitor concentration. The outputs for each ANN model and the components in the EIS spectrum (Zre, Zim, and Zmod) were predicted. The transfer functions used for the learning process were the hyperbolic tangent sigmoid in the hidden layer and linear in the output layer, while the Levenberg-Marquardt algorithm was applied to determine the optimum values of the weights and biases. The statistical analysis of the results revealed that ANN models for Zre, Zim, and Zmod can successfully predict the inhibition corrosion behavior of bronze in different conditions, where what was considered included variability in temperature, frequency, and inhibitor concentration. In addition, these three input parameters were keys to describe the behavior according to a sensitivity analysis.

Does the Pulsatile Preservation Machine Have Any Impact in the Discard Rate of Kidneys From Older Donors After Brain Death?

BACKGROUND: Donors after brain death (DBD) older than 60 years have become 46.8% of our current activity, with higher risk of renal discard rate (RDR). Assessment of kidney suitability requires complementary strategies: macroscopic evaluation, kidney biopsy score (KBS), and renal hemodynamic evaluation with the Pulsatile Perfusion Machine (PPM). METHODS: Descriptive, cross-sectional, comparative study of kidneys procured and RDR, comparing 3 time periods: 2000 to June 2004, when only KBS were used; July 2004 to 2008 (introduction of PPM and learning period); and 2009 to 2013 (experienced use of PPM). Transplantation criteria were KBS <3 and PPM renal resistance <0.4 mm Hg/mL/min and arterial renal flow >70 mL/min. RESULTS: Between 2000 and 2013, a 59.2% reduction in DBD kidneys was observed. However, older kidneys had an increase from 33.5% to 46.8%. The RDR had increased, comparing the first to the third period from 25.4% to 38.3%. However, the RDR was lower when kidneys were evaluated with PPM than those evaluated only with KBS and preserved in cold storage (CS) (21.4% versus 43.7%). There was a significant difference in cold ischemia time, because CS kidney was grafted before PPM. During the third period, more kidneys with KBS ≥4 were assigned to PPM. CONCLUSIONS: Notwithstanding the decrease in DBD-procured kidneys and the increase in older kidneys during last period, the use of PPM allowed low DR compared with CS. A bias in the results of PPM could be generated when kidneys with higher KBS were excluded from PPM. The use of KBS only to decide acceptance could preclude the use of an additional tool to evaluate suitability.

A study on the discrimination of human skeletons using X-ray fluorescence and chemometric tools in chemical anthropology.

Forensic anthropological investigations are often restricted in their outcomes by the resources allocated to them, especially in terms of positively identifying the victims exhumed from commingled mass graves. Commingled mass graves can be defined as those graves that contain a number of disarticulated human remains from different individuals that have been mixed by either natural processes or human interventions. The research developed aimed to apply the technique of non-destructive XRF analysis to test whether there is substantial differentiation within the trace elemental composition and their ratios of individuals to separate them using chemometric analysis. The results of the different atomic spectroscopic analyses combined with the use of multivariate analysis on a set of 5 skeletons produced a series of plots using Principal Component Analysis that helped to separate them with a high percentage of accuracy when two, three or four skeletons needed to be separated. Also, two new elemental ratios, Zn/Fe related to metabolic activities and K/Fe related to blood flow into the bone, have been defined for their use in forensic anthropology for the first time to aid in the separation.

Pseudoaneurisma poplíteo como complicación de la artroplastia total de rodilla. Revisión y actualización bibliográfica a propósito de un caso / Popliteal pseudoaneurysm as a complication in total knee replacement. Presentation of a case and an updated literature review

Las complicaciones vasculares después de cirugía protésica de rodilla son poco frecuentes. Dentro de este grupo, el pseudoaneurisma de la arteria poplítea es todavía más raro, habiéndose reportado en la literatura unos pocos casos. Presentamos el caso de una mujer de 80 años con el diagnóstico de gonartrosis izquierda por genu varo que fue intervenida de prótesis total de rodilla y que en el postoperatorio tardío previo al alta, presentó un pseudoaneurisma de la arteria poplítea que fue tratado satisfactoriamente mediante un stent intravascular por abordaje inguinal (AU)

Vascular complications are rare after total knee arthroplasty, and popliteal pseudoaneurysms are even more so. There are few cases reported in the literature. We present a case of an 80 year-old woman with osteoarthritis of the left knee, secondary to Genu varum, who was treated with total knee arthroplasty. On the discharge day after surgery, the patient suffered a popliteal pseudoaneurysm that was successfully treated with an intravascular stent introduced by an inguinal approach (AU)

[Popliteal pseudoaneurysm as a complication in total knee replacement. Presentation of a case and an updated literature review]. / Pseudoaneurisma poplíteo como complicación de la artroplastia total de rodilla. Revisión y actualización bibliográfica a propósito de un caso.

Vascular complications are rare after total knee arthroplasty, and popliteal pseudoaneurysms are even more so. There are few cases reported in the literature. We present a case of an 80 year-old woman with osteoarthritis of the left knee, secondary to Genu varum, who was treated with total knee arthroplasty. On the discharge day after surgery, the patient suffered a popliteal pseudoaneurysm that was successfully treated with an intravascular stent introduced by an inguinal approach.