Al – AlBx (x = 2,12), AA6060 – AlBx (x = 2,12) and AA5083 – AlBx (x = 2,12) composites with 3 wt % AlBx particles were developed by in-situ reaction of molten aluminium and alloys (AA5083 and AA6060) ...with inorganic salt KBF4 at a temperature of 900 °C. The chemical reaction produces boron, which dissolves into the molten alloy and subsequently forms aluminium borides (AlB2 and AlB12). The thermodynamic properties of the reactions are calculated by HSC Chemistry 6.0 software. In the case of aluminium matrix the melt solidified in the crucible, between 980 °C and 200 °C, in order to develop the peritectic reaction AlB12 + 5Al(l) = 6AlB2.
It was found that both in the case of aluminium and aluminium alloys the peritectic reaction occurs partially. The composites were characterised by SEM and XRD analysis. The stress-strain measurement showed 8% improvement towards the matrix alloys. The fracture features of composites were examined using SEM analysis. Ductile and brittle locally fractography is revealed. Composites exhibited a higher resistance to crack initiation than the matrix alloys. The results obtained in the experiments and analysis helps to clarify the mechanism of interaction between liquid aluminium and KBF4 at high temperatures.
The Eigen-vector co-registeration is not as simple as FA co-registeration due to the cancellation of the vector direction on some interpolated point when the original voxel vectors is inversion. ...Because the Eigen-vectors are unit vectors, normalization are applied to eigen-vectors in a voxel by voxel fashion. Closest neighbor interpolation produced the most consistent results with the original fiber tracking, the FA changing by 3.9% and 2.2% and number of fibers changing by 5.1% and 3.6% on the 2 subjects respectively.
Currently, hydrogen may be stored as a compressed gas or as cryogenic liquid. Neither method appears to be practical for many applications in which hydrogen use would otherwise be attractive. For ...example, gaseous storage of stationary fuel is not feasible because of the large volume or weight of the storage vessels. Liquid hydrogen could be used extensively but the liquefaction process is relatively expensive. The hydrogen can be stored for a long term with a high separation factor, like solid metal hydride. Using hydride-forming metals and intermetallic compounds, for example, recovery, purification and storage of heavy isotopes in a tritium-containing system, can solve many problems arising in the nuclear fuel cycle. This paper presents a comparative study about hydrogen sorption obtained from a cryogenic distillation process, on two titanium structures: powder and sponge. Also presented is the characterization, by X-ray diffraction, of two structures, before and after the sorption process.
Abstract Introduction Left atrium (LA) and left atrial appendage (LAA) thrombus may occur during atrial fibrillation (AF) and atrial flutter (AFl), and potentially cause main embolic events. Sludge ...is a pre-thrombotic condition, associated with long term adverse outcomes. Current guidelines do not recommend to perform transesophageal echocardiography (TEE) before cardioversion (CV) of patients with persistent AF/AFl when at least 3 weeks of anticoagulation are administered with appropriate compliance. Instead, they suggest TEE before atrial ablations (Abl), even in anticoagulated patients. Evidence to support these approaches are weak and conflicting, due to not infrequent occurrence of peri-procedural stroke and several reports of not negligible prevalence of LAA thrombus finding. Purpose Aim of the study was to evaluate the real prevalence of LAA thrombus and sludge in a retrospective cohort of consecutive anticoagulated patients with persistent AF and AFl, who underwent TEE before a scheduled cardioversion or catheter ablation. Moreover, clinical and echocardiographic characteristics were analyzed to develop a score that could predict the individual risk of combined thrombus/sludge. Methods We conducted a retrospective, monocentric, observational study, recruiting 1037 consecutive patients with persistent AF/AFl referred to our center for CV or Abl. TEE had been always performed to rule out thrombus and sludge before procedures. We collected data about patients characteristics, medication and compliance, electrographic and echocardiographic findings and type of scheduled procedure. Data was compared in univariate and multivariate analysis to identify possible predictors of LAA thrombus and sludge, and we used the last significant results to create a predictive score with logistic regression analysis. We identified best cutoff value with ROC curve. Results 767 patients were included in final dataset. Mean CHA2DS2-VASc was 3.2. LA/LAA thrombus and sludge were identified in 63 subjects (8.21%), 17 thrombi (2.21%) and 45 sludge (5.86%). Presence of valvular AF (+1), previous stroke or TIA (+1.5), heart failure history (+1), ventricular systolic (LVEF < 45%)(+0.5) and diastolic (Lateral E/e’ > 9) dysfunctions (+1) were significantly associated to higher risk of thrombus/sludge occurrence, meanwhile AFl (-1) was associated to lower risk. A novel score, called HEELP score, was developed based on these variables, and a threshold of 1 point showed high sensitivity (89%) and remarkable negative predictive value (98%). Conclusion Thrombus and sludge prevalence is not infrequent in anticoagulated patients with persistent AF/AFl. A strategy to perform TEE before procedures in patients with high risk features according to our score could be effective in preventing main embolic events, but it has to be validated in further studies.LAA empty (1), sludge (2), thrombus (3)HEELP score
The profile of brain structural abnormalities in schizophrenia is still not fully understood, despite decades of research using brain scans. To validate a prospective meta-analysis approach to ...analyzing multicenter neuroimaging data, we analyzed brain MRI scans from 2028 schizophrenia patients and 2540 healthy controls, assessed with standardized methods at 15 centers worldwide. We identified subcortical brain volumes that differentiated patients from controls, and ranked them according to their effect sizes. Compared with healthy controls, patients with schizophrenia had smaller hippocampus (Cohen's d=-0.46), amygdala (d=-0.31), thalamus (d=-0.31), accumbens (d=-0.25) and intracranial volumes (d=-0.12), as well as larger pallidum (d=0.21) and lateral ventricle volumes (d=0.37). Putamen and pallidum volume augmentations were positively associated with duration of illness and hippocampal deficits scaled with the proportion of unmedicated patients. Worldwide cooperative analyses of brain imaging data support a profile of subcortical abnormalities in schizophrenia, which is consistent with that based on traditional meta-analytic approaches. This first ENIGMA Schizophrenia Working Group study validates that collaborative data analyses can readily be used across brain phenotypes and disorders and encourages analysis and data sharing efforts to further our understanding of severe mental illness.
In this paper we introduce a diffractive structure with a geometry which contains multiple Fresnel zone plates (MFZP) disposed in an arrangement based on a fractal-like rule. The corresponding ...diffracted intensity in planes perpendicular to the propagation axe presents two or more focal points. Their position and magnitude depend on geometrical parameters of the MFZP and on dimensions in the fractal-like arrangement. In our simulations we also analyze the influence in diffraction pattern of different non-binary phase levels in the MFZP plane. The MFZP structures with different values of geometrical and phase parameters are addressed to an optoelectronic device liquid crystal spatial light modulator (LCSLM), the experimental and simulation results are in a good agreement. The MFZP geometry with better optical parameters in diffraction pattern is then made on glass using electron beam lithography technique.
The safety and tolerability of the selective serotonin reuptake inhibitors and the newer atypical agents have led to a significant increase in antidepressant use. These changes raise concern as to ...the likelihood of a corresponding increase in adverse behavioral reactions attributable to these drugs.
All admissions to a university-based general hospital psychiatric unit during a 14-month period were reviewed.
Forty-three (8.1%) of 533 patients were found to have been admitted owing to antidepressant-associated mania or psychosis.
Despite the positive changes in the side effect profile of antidepressant drugs, the rate of admissions due to antidepressant-associated adverse behavioral effects remains significant.
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