Thermodynamic assessment and microscale Raman spectroscopy of binary CO2/CH4 hydrates produced during replacement applications in natural reservoirs

The present research deals with the micro – scale characterization of sI hydrates containing a binary mixture of methane and carbon dioxide. The application of replacement strategies in natural hydrate reservoirs, always leads to the formation of “mixed” hydrates, whose mechanical and chemical properties are different from those of pure CH4 and CO2 hydrates. As a function of the technique used for the process and due to the variability of the systems, a wide range of different compositions and morphologies can be obtained and the current literature must be expanded, in order to achieve a wide and accurate experimental database of CO2/CH4 hydrate properties. In this work, binary CO2/CH4 hydrates binary CO2/CH4 hydrates were produced in a small – scale reactor and then supercooled, in order to favour their extraction from the reactor and their stability at environmental conditions for a certain period of time. The gas hydrates, prepared with CO2 hydrates of pure water and with CH4 and CO2 mixtures, also in the presence of specific sands, were ex situ analysed by the use Raman-spectroscopy that confirmed the gas uptake in the hydrate structures by identification of the fingerprint of CH4 and CO2 occupancy in the hydrates. The characteristic of water inside the gas hydrates and the interaction between the host molecules and the lattice of water molecules was clarified. The different gas hydrates, analysed by Field Emission Scanning Electron Microscopy instrument equipped with “Coolstage head” under high vacuum condition, differed in morphology and surface features. The analysis of water Raman spectra of the different GHs permitted to describe the relation between symmetric and asymmetric OHs bands, but also provided information about the characteristics of water inside the different GHs, showing that the least ordered water structure was that of GHs containing sand, while the most ordered one was present on binary CO2/CH4 hydrates

May sediments affect the inhibiting properties of NaCl on CH4 and CO2 hydrates formation? an experimental report.

The equilibria of methane and carbon dioxide clathrate hydrates were measured in presence of a pure-quartz porous sand, with and without NaCl. Two different salt concentrations were tested: 0.030 and 0.037 wt%. Results were compared with phase equilibrium data already present in literature for these species. Despite salt, the porous medium was found to promote the process, mainly for the increased surface/volume ratio and for the improved heat transfer. In presence of salt, sand affected the process differently as a function of temperature: at values higher than 3 – 5 °C, it promoted the process, while for values lower than this range, but still greater than the ice-point, it acted as an inhibitor. However, these results can be considered true only for temperatures above the ice point. Due to similarity of ice water with clathrate hydrates, Raman microscale measurements were performed to gather information about the influence of sediments, salt, and temperature on OH-stretching vibrations of water. The obtained results allowed to clarify how the addition of NaCl, and or sediments to liquid water, under different temperature conditions (15 °C and −15 °C), influenced the water hydrogen bonds. Specifically, the changes of OH-stretching vibrations, when correlated with the NaCl concentrations, demonstrated that the presence of sediments partially inhibited the salt effects in the ice water probably due to hydrophilic interactions with the silanol groups of sediments. SEM measurements showed morphological information on sediments and on ice in different experimental conditions

New generation of wearable goniometers for motion capture systems

Background Monitoring joint angles through wearable systems enables human posture and gesture to be reconstructed as a support for physical rehabilitation both in clinics and at the patient's home. A new generation of wearable goniometers based on knitted piezoresistive fabric (KPF) technology is presented. Methods KPF single-and double-layer devices were designed and characterized under stretching and bending to work as strain sensors and goniometers. The theoretical working principle and the derived electromechanical model, previously proved for carbon elastomer sensors, were generalized to KPF. The devices were used to correlate angles and piezoresistive fabric behaviour, to highlight the differences in terms of performance between the single layer and the double layer sensors. A fast calibration procedure is also proposed. Results The proposed device was tested both in static and dynamic conditions in comparison with standard electrogoniometers and inertial measurement units respectively. KPF goniometer capabilities in angle detection were experimentally proved and a discussion of the device measurement errors of is provided. The paper concludes with an analysis of sensor accuracy and hysteresis reduction in particular configurations. Conclusions Double layer KPF goniometers showed a promising performance in terms of angle measurements both in quasi-static and dynamic working mode for velocities typical of human movement. A further approach consisting of a combination of multiple sensors to increase accuracy via sensor fusion technique has been presented

Comparative study of etiological diagnosis of nosocomial pneumonia

Nosocomial pneumonia is a common complication in patients on mechanical ventilation and results in significant mortality. Diagnosis of pneumonia in patients who are intubated and under mechanical ventilation is difficult, even with the aid of clinical, laboratorial, and endoscopic tests. The objective of this study was to compare three methods of tracheal sputum collection in patients with a clinical and radiological diagnosis of pneumonia. Twenty-two patients with a clinical diagnosis of liver disease were enrolled, 18 years of age or older, 13 males and nine females, who had been mechanically ventilated over an intubation period of 5.86 ± 4.62 days. These patients were being treated in intensive care unit (ICU) of the Liver Transplantdepartment. Secretion collection was carried out according to a protocol with three distinct methods: endotracheal aspiration with a closed aspiration system, Bal cath and bronchoalveolar lavage. Of the 22 patients analyzed, 21 (95.4%) showed one or more infectious agent when the closed aspiration system was used. With the Bal cathâ collection, 19 patients (86.3%) had one or more infectious agents; in the collection by bronchoalveolar lavage, 10 patients (45.4%) presented one or more infectious agent. According to the laboratorial analysis, 14 different microorganisms were isolated, the most frequent of which were Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. We concluded that aspiration with the closed system produced the most effective results in comparison with those of bronchoalveolar lavage and the Bal cathâ, and may be an acceptable method for diagnosing hospital-acquired pneumonia when no fiberoptic technique is available

Relações entre a coleta de dados, diagnósticos e prescrições de enfermagem a pacientes adultos de uma unidade de terapia intensiva

This descriptive, retrospective study aimed to analyze the relation between nursing data collection, diagnoses and prescriptions for 26 adult patients who were hospitalized at the intense care unit of a large teaching hospital for at least 24 hours. Through the analysis of medical records, 135 diagnoses and 421 nursing prescriptions were established, and 24 different diagnosis categories and 20 different items for prescriptions were identified. The most frequent diagnosis risk was that for infection, present in the medical records of 22 (84.60%) patients, with 175 prescriptions (42%) related to this diagnosis. The data the nurses collected were sufficient to establish the nursing diagnoses, and the majority of prescriptions (87.9%) were related to the diagnoses.La finalidad de este estudio descriptivo y retrospectivo fue analizar la relación entre la recolección de datos, diagnósticos y prescripciones de enfermería para 26 pacientes adultos que estuvieron hospitalizados en una unidad de terapia intensiva en un hospital de enseñanza de gran porte, con permanencia mínima de 24 horas. Mediante el análisis de los archivos se establecieron 135 diagnósticos y 421 prescripciones de enfermería, siendo identificados 24 categorías de diagnóstico y 20 diferentes ítems de prescripción. El diagnóstico de riesgo para la infección fue el más frecuente, que estuvo presente en el registro de 22 (84,60%) pacientes. De las prescripciones, 175 (42%) se refirieron a este diagnóstico. Se observa que los datos registrados por los enfermeros en la recolección de datos fueron suficientes para establecer los diagnósticos de enfermería y que la mayoría de las prescripciones (87,9%) estuvieron relacionadas con los diagnósticos.Trabalho descritivo, retrospectivo, que teve como objetivo analisar a relação entre a coleta de dados, diagnósticos e prescrições de enfermagem estabelecidas por enfermeiros para 26 pacientes adultos que estiveram internados numa unidade de terapia intensiva de um hospital de ensino de grande porte, com permanência mínima de 24 horas. Por meio da análise dos prontuários, foram estabelecidos 135 diagnósticos e 421 prescrições de enfermagem, sendo identificadas 24 diferentes categorias diagnósticas e 20 diferentes itens para prescrição. O diagnóstico de risco para infecção foi o de maior freqüência, presente no prontuário de 22 (84,60%) pacientes. Das prescrições, 175 (42%) relacionaram-se a esse diagnóstico. Observa-se que os dados registrados pelos enfermeiros na coleta de dados foram suficientes para o estabelecimento dos diagnósticos de enfermagem e a maioria das prescrições (87,9%) apresentou relação com os diagnósticos.CNP

Modelling the Fenton reaction of amphibole asbestos

In this work a sample of UICC crocidolite and a sample of fibrous tremolite were leached up to 1 week both in a simplified Gamble’s solution at acidic pH and in a phosphate buffered medium at neutral pH, in presence of H2O2. Surface chemical modifications were monitored by XPS spectroscopy. Subsequently, the generation of HO• radicals following reaction of both pristine and leached fibres with H2O2 (Fenton reaction) was investigated by spin trapping/EPR spectroscopy, with the aim of better clarifying the relationships between possible surface alteration occurring in vivo and chemical reactivity of amphibole asbestos. Moreover, the generation of HO• radicals was monitored on thermally treated fibres after leaching in phosphate buffered medium at neutral pH and in presence of H2O2 to investigate how chemical reactivity may be modulated by Fe oxidation state. Results showed that, for both amphibole asbestos, the surface alteration following incubation in the modified Gamble’s solution does not alter HO• radical generation. Interestingly, leaching in phosphate buffered solution in presence of H2O2 induced a progressive increase in HO• release for crocidolite fibres, whereas a strong reduction was observed for asbestos tremolite. This behaviour is likely due to the quicker alteration of the crocidolite surface due to the interaction with H2O2, as indicated by XPS analysis. In particular, the oxidation induced by H2O2 promotes the dissolution of the first atomic layer of the crocidolite structure and the following occurrence on its surface of new reactive Fe centres, particularly under the form of Fe(II), of which the bulk is richer than the oxidized surface. Accordingly, the heated samples showed a reduced, but not suppressed by thermal oxidation, chemical reactivity, with no significant evolution following incubation in phosphate buffered medium at neutral pH and in presence of H2O2

Myelodysplastic syndromes: advantages of a combined cytogenetic and molecular diagnostic workup

In this study we present a new diagnostic workup for the myelodysplastic syndromes (MDS) including FISH, aCGH, and somatic mutation assays in addition to the conventional cytogenetics (CC). We analyzed 61 patients by CC, FISH for chromosome 5, 7, 8 and PDGFR rearrangements, aCGH, and PCR for ASXL1, EZH2, TP53, TET2, RUNX1, DNMT3A, SF3B1 somatic mutations. Moreover, we quantified WT1 and RPS14 gene expression levels, in order to find their possible adjunctive value and their possible clinical impact. CC analysis showed 32% of patients with at least one aberration. FISH analysis detected chromosomal aberrations in 24% of patients and recovered 5 cases (13.5%) at normal karyotype (two 5q- syndromes, one del(7) case, two cases with PDGFR rearrangement). The aGCH detected 10 "new" unbalanced cases in respect of the CC, including one with alteration of the ETV6 gene. After mutational analysis, 33 patients (54%) presented at least one mutation and represented the only marker of clonality in 36% of all patients. The statistical analysis confirmed the prognostic role of CC either on overall or on progression-free-survival. In addition, deletions detected by aCGH and WT1 over-expression negatively conditioned survival. In conclusion, our work showed that 1) the addition of FISH (at least for chr. 5 and 7) can improve the definition of the risk score; 2) mutational analysis, especially for the TP53 and SF3B1, could better define the type of MDS and represent a "clinical warning"; 3) the aCGH use could be probably applied to selected cases (with suboptimal response or failure)

Relaciones entre la recolección de datos, diagnósticos y prescripciones de enfermería a pacientes adultos en una unidad de terapia intensiva

Trabalho descritivo, retrospectivo, que teve como objetivo analisar a relação entre a coleta de dados, diagnósticos e prescrições de enfermagem estabelecidas por enfermeiros para 26 pacientes adultos que estiveram internados numa unidade de terapia intensiva de um hospital de ensino de grande porte, com permanência mínima de 24 horas. Por meio da análise dos prontuários, foram estabelecidos 135 diagnósticos e 421 prescrições de enfermagem, sendo identificadas 24 diferentes categorias diagnósticas e 20 diferentes itens para prescrição. O diagnóstico de risco para infecção foi o de maior freqüência, presente no prontuário de 22 (84,60%) pacientes. Das prescrições, 175 (42%) relacionaram-se a esse diagnóstico. Observa-se que os dados registrados pelos enfermeiros na coleta de dados foram suficientes para o estabelecimento dos diagnósticos de enfermagem e a maioria das prescrições (87,9%) apresentou relação com os diagnósticos.La finalidad de este estudio descriptivo y retrospectivo fue analizar la relación entre la recolección de datos, diagnósticos y prescripciones de enfermería para 26 pacientes adultos que estuvieron hospitalizados en una unidad de terapia intensiva en un hospital de enseñanza de gran porte, con permanencia mínima de 24 horas. Mediante el análisis de los archivos se establecieron 135 diagnósticos y 421 prescripciones de enfermería, siendo identificados 24 categorías de diagnóstico y 20 diferentes ítems de prescripción. El diagnóstico de riesgo para la infección fue el más frecuente, que estuvo presente en el registro de 22 (84,60%) pacientes. De las prescripciones, 175 (42%) se refirieron a este diagnóstico. Se observa que los datos registrados por los enfermeros en la recolección de datos fueron suficientes para establecer los diagnósticos de enfermería y que la mayoría de las prescripciones (87,9%) estuvieron relacionadas con los diagnósticos.This descriptive, retrospective study aimed to analyze the relation between nursing data collection, diagnoses and prescriptions for 26 adult patients who were hospitalized at the intense care unit of a large teaching hospital for at least 24 hours. Through the analysis of medical records, 135 diagnoses and 421 nursing prescriptions were established, and 24 different diagnosis categories and 20 different items for prescriptions were identified. The most frequent diagnosis risk was that for infection, present in the medical records of 22 (84.60%) patients, with 175 prescriptions (42%) related to this diagnosis. The data the nurses collected were sufficient to establish the nursing diagnoses, and the majority of prescriptions (87.9%) were related to the diagnoses

QRS Complex Separation from Convolutive Mixtures of Biolectrical Signals Acquired by Wearable Systems

Independent component analysis (ICA) has been widely used to remove artefacts from multichannel biomedical signal acquisitions under the hypothesis that there is statistical independence among the original sources. However, the basic ICA model does not take into account the influence on the mixing process of the different paths from the signal sources to the sensors In this study we propose a convolutive mixtures model in order to overcome the limitations of the basic ICA approach. The independent components are estimated in the frequency domain, where the convolutive model can be solved through an instantaneous mixing model. The signals are reconstructed back to the observation space resolving the ICA model ambiguities. Simulations are carried out to optimize of the proposed method for convolutive mixtures of electrocardiographic (ECG) and motion artefacts signals. The algorithm is tested on real ECG signals acquired by wearable systems in order to preserve the QRS complex when the signals are degraded by real life conditions of acquisition