•A trigeneration process of H2, electricity and desalinated water was proposed and studied.•It is based on the technologies Na-O-H cycle, SCWR power plant and MED desalination.•Mass, energy and ...exergy balances are applied to evaluate trigeneration thermal performance.•EES software was used to model the studied systems.•Such process has potential to produce 5 kg/s of H2, 400 MWe and 980 kg/s of H2O.
Hydrogen (H2) is a substance with a wide range of applications, especially ammonia (NH3) production. It is the key chemical used to make fertilizers, a pillar of agriculture industry, an important activity for society. H2 can be obtained according to different processes, including the recent method Na-O-H (sodium-oxygen-hydrogen) thermochemical water splitting cycle that produce it by cracking H2O (water) molecules into H2 and O2 (oxygen) through cyclic chemical reactions based on the elements Na, O and H. Such reactions are sustained by a heat source at specified temperature level. In this context, nuclear reactors, such as Supercritical Water Reactor (SCWR), are suitable energy options for this kind of process because they are designed to support electricity together with high temperature applications like H2 production. At the same time, water could be get by means of MED (Multi-Effect Distillation), a desalination method able to harvest waste heat from thermal systems. This approach allows saving the available potable water to be used in essential human needs such as drinking and agriculture while the desalinated one would serve as hydrogen source in the sodium-oxygen-hydrogen technique. Then, H2 production based on the technologies Na-O-H cycle through the heat supplied by SCWR coupled to a MED unit enables the trigeneration of electricity-hydrogen-water, three important goods for current society, what justifies the development of a paper covering this multigeneration approach. So, the main aim of this work is to evaluate the thermodynamic performance of this trigeneration case, a task never done before because those three systems were not coupled together aiming this multigeneration case as it was checked in the literature. It was considered a SCWR with output thermal power equal to 1000 MWth as the heat source to both Na-O-H hydrogen production facility plus MED installation. The work is developed by implementing mass and energy balances in Engineering Equation Solver (EES) software to determine the amount of H2, electricity and desalinated H2O acquired. According to the main results, this trigeneration process has potential to produce a maximum of 5 kg/s of hydrogen, 400 MW of electricity and 960 kg/s of desalinated H2O.
Purpose To evaluate the feasibility of a standardized protocol for acquisition and analysis of dynamic contrast material-enhanced (DCE) and dynamic susceptibility contrast (DSC) magnetic resonance ...(MR) imaging in a multicenter clinical setting and to verify its accuracy in predicting glioma grade according to the new World Health Organization 2016 classification. Materials and Methods The local research ethics committees of all centers approved the study, and informed consent was obtained from patients. One hundred patients with glioma were prospectively examined at 3.0 T in seven centers that performed the same preoperative MR imaging protocol, including DCE and DSC sequences. Two independent readers identified the perfusion hotspots on maps of volume transfer constant (K
), plasma (v
) and extravascular-extracellular space (v
) volumes, initial area under the concentration curve, and relative cerebral blood volume (rCBV). Differences in parameters between grades and molecular subtypes were assessed by using Kruskal-Wallis and Mann-Whitney U tests. Diagnostic accuracy was evaluated by using receiver operating characteristic curve analysis. Results The whole protocol was tolerated in all patients. Perfusion maps were successfully obtained in 94 patients. An excellent interreader reproducibility of DSC- and DCE-derived measures was found. Among DCE-derived parameters, v
and v
had the highest accuracy (are under the receiver operating characteristic curve A
= 0.847 and 0.853) for glioma grading. DSC-derived rCBV had the highest accuracy (A
= 0.894), but the difference was not statistically significant (P > .05). Among lower-grade gliomas, a moderate increase in both v
and rCBV was evident in isocitrate dehydrogenase wild-type tumors, although this was not significant (P > .05). Conclusion A standardized multicenter acquisition and analysis protocol of DCE and DSC MR imaging is feasible and highly reproducible. Both techniques showed a comparable, high diagnostic accuracy for grading gliomas.
RSNA, 2018 Online supplemental material is available for this article.
Parkinson's disease (PD) is a progressive neurodegenerative disorder in which the major pathologic substrate is a loss of dopaminergic neurons from the substantia nigra. Our main objective was to ...determine the correspondence between changes in the substantia nigra, evident in neuromelanin and iron sensitive magnetic resonance imaging (MRI), and dopaminergic striatal innervation loss in patients with PD. Eighteen patients and 18 healthy control subjects were included in the study. Using neuromelanin-MRI, we measured the volume of the substantia nigra and the contrast-to-noise-ratio between substantia nigra and a background region. The apparent transverse relaxation rate and magnetic susceptibility of the substantia nigra were calculated from dual-echo MRI. Striatal dopaminergic innervation was measured as density of dopamine transporter (DAT) by means of single-photon emission computed tomography and (123)I N-ω-fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl) tropane. Patients showed a reduced volume of the substantia nigra and contrast-to-noise-ratio and both positively correlated with the corresponding striatal DAT density. The apparent transverse relaxation rate and magnetic susceptibility values of the substantia nigra did not differ between patients and healthy controls. The best predictor of DAT reduction was the volume of the substantia nigra. Clinical and imaging correlations were also investigated for the locus coeruleus. Our results suggest that neuromelanin-MRI can be used for quantifying substantia nigra pathology in PD where it closely correlates with dopaminergic striatal innervation loss. Longitudinal studies should further explore the role of Neuromelanin-MRI as an imaging biomarker of PD, especially for subjects at risk of developing the disease.
Anisakis simplex spp. sensitization rates have increased worldwide, with a significant impact on health-care systems. To date, no clear-cut diagnostic criteria and laboratory algorithm have been ...established, so anisakiasis still represents an under-reported health problem whose clinical manifestations, when present, mimic the much more common allergic and digestive disorders. Aim of the study was to systematically review the available literature on the prevalence of sensitization against Anisakis in the general population and in specific population groups, taking into account the impact of the different available diagnostic techniques on the epidemiological data. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, relevant papers reporting Anisakis sensitization epidemiological data were found covering a period ranging from 1996 to February 2017. Overall, 41 studies comprising 31,701 participants from eleven countries were included in the qualitative synthesis. General asymptomatic population resulted sensitized to Anisakis in 0.4 to 27.4% of cases detected by means of indirect ELISA or ImmunoCAP specific IgE detection, and between 6.6% and 19.6% of the samples by Skin prick test (SPT). Occupationally exposed workers (fishermen, fishmongers and workers of fish-processing industries) documented specific IgE between 11.7% and 50% of cases, whereas SPT positivity ranged between 8% and 46.4%. Symptomatic allergic patients to any kind of allergen were found to be positive to Anisakis specific IgE detection between 0.0% (in children with mastocytosis) to 81.3% (among adults with shellfish allergy). Results highlighted that hypersensitivity prevalence estimates varied widely according to geographical area, characteristics of the population studied, diagnostic criteria and laboratory assays. Further studies are needed to overcome the documented misdiagnosis by improving the diagnostic approach and, consequently, providing more affordable estimates in order to address public health interventions on populations at high risk of exposure to Anisakis and to tailor health services related to specific groups.
Human cases of gastric anisakiasis caused by the zoonotic parasite Anisakis pegreffii are increasing in Italy. The disease is caused by ingestion of larval nematodes in lightly cooked or raw seafood. ...Because symptoms are vague and serodiagnosis is difficult, the disease is often misdiagnosed and cases are understimated.
Objective
Since the introduction of cone-beam computed tomography (CBCT) in dentistry, this technology has enabled distortion-free three-dimensional cephalometric analysis for orthodontic and ...orthognathic surgery diagnosis. However, CBCT is associated with significantly higher radiation exposure than traditional routine bidimensional examinations for orthodontic diagnosis, although low-dose protocols have markedly reduced radiation exposure over time.
The objective of this preliminary feasibility study is to compare the accuracy and diagnostic capabilities of an already-validated three-dimensional cephalometric analysis on CBCT to those of an analysis on 3-T magnetic resonance imaging (3T-MRI) to assess whether the latter can deliver a comparable quality of information while avoiding radiation exposure.
Materials and methods
In order to test the feasibility of three-dimensional cephalometry on 3T-MRI, 18 subjects (4 male; 14 female) with mean age 37.8 ± SD 10.2, who had undergone both maxillofacial CBCT and maxillofacial 3T-MRI for various purposes within 1 month, were selected from the archive of the Department of Dentistry and Maxillofacial Surgery of Fondazione Ospedale Policlinico Maggiore, IRCCS, Milano, Italy.
A three-dimensional cephalometric analysis composed of ten midsagittal and four bilateral landmarks and 24 measurements (11 angular, 13 linear) was performed on both scans using Mimics Research® v. 17.0 (NV, Technologielaan 15, 3001 Leuven, Belgium). Cephalometric analysis was performed twice by two independent orthodontists for each scan, and each orthodontist repeated the measurements 3 weeks later. Statistical analysis was performed with SPSS® 20.00 for Windows (IBM® Corporation, Sommers, NY, USA). A Bland-Altman test for each cephalometric value was performed to assess the agreement between the procedures. The intraclass correlation coefficient (ICC) was used to assess interobserver and intraobserver reliability. The coefficient of variation was used to evaluate precision.
Results
Both procedures showed good reliability, with mean intraobserver ICCs of 0.977/0.971 for CBCT and 0.881/0.912 for MRI. The average interobserver ICCs were 0.965 for CBCT and 0.833 for MRI. A Bland-Altman analysis for the cephalometric tracing revealed a similar range of agreement between the two modalities; the bias range (mean ± SD) was − 0.25–0.66 mm (0.174 ± 0.31) for distances and − 0.41–0.54° (0.12 ± 0.33) for angles.
Conclusions
Within the main limitation of this pilot study, that is, the small sample, it is possible to state that cephalometric measurements on 3T-MRI seem to possess adequate reliability and repeatability and that they show satisfying agreement with values measured on CBCTs. An MRI examination does not expose patients to ionizing radiation and could provide an alternative to CBCT for three-dimensional cephalometrics in the future.
The vulnerability of electric potential generation from water resources has been evidenced due to uncertainties of climatic origin and energy planning. Changes in rainfall regimes are multifactorial ...phenomena difficult to model. Rainfall is the main natural way of restoring the reservoir levels of hydroelectric power plants. The reduction in rainfall levels may increase in the coming years, resulting in a probable change of the energy matrix configuration of the state of Minas Gerais (MG). This could reduce the share of renewable sources increasing dependence on the importance of energy from fossil fuels, which are the immediate primary sources of energy available. Prior examinations have portrayed the depletion of hydroelectricity in Brazil, or its macro-regions, however this work tries to supply a more focused look at the effects on the electricity and social sectors of the state of Minas Gerais. The study developed in this paper aims to investigate the hydrological potential alteration impacts and consequences on the energy matrix of the state, the greenhouse gas emissions and the social reflexes of these changes due to scenarios motivated by climate change. The investigation intends to show the importance of the water-energy-emissions nexus for energy planning and decision-making, in order to evaluate the best options for dealing with adverse and potentially destabilizing conditions. The results of the analyses show that while hydropower demand was 5.24 Mtoe in 2015, in 2030 the supply of hydropower will be 5.81 Mtoe and 4.72 Mtoe, for the conservative and severe scenarios, respectively. In addition, the effect of climate change may require an increase in the share of non-renewable sources in the energy matrix, which could increase CO2e emissions from 4.2% to 7.4% by 2030, compared to the levels in 2016.
•Reduction in rainfall levels will change the energy matrix configuration of MG state.•Population growth will boost demand for energy.•It is shown the importance of the water-energy-emissions nexus for energy planning and decision-making.•The energy matrix may considerably increase the CO2e emissions by 2030, compared with 2016 levels in the MG state.
spp. are emerging waterborne and foodborne zoonotic pathogens responsible for gastroenteritis in humans. In this work, we evaluated the occurrence and the antimicrobial resistance profile of
isolates ...recovered from different aquatic sources. Besides, we searched for
spp. in seaweeds and the corresponding seawater samples. Bacteriological and molecular methods applied to 100 samples led to the isolation of 28
isolates from 27 samples. The highest prevalence was detected in rivers followed by artificial ponds, streams, well waters, and spring waters. Seaweeds contained a higher percentage of
than the corresponding seawater samples. The isolates were identified as
(96.4%) and
(3.6%). All the isolates showed a multi-drug resistance profile, being resistant to at least three different classes of antibiotics. Molecular analysis of genetic determinants responsible for tetracycline resistance in nine randomly chosen isolates revealed the presence of
and/or
This work confirms the occurrence and the continuous emergence of antibiotic-resistant
strains in environmental samples; also, the presence of quinolone-resistant
spp. in aquatic sources used for water supply and irrigation represents a potential risk for human health.
Summary
National energy planning aims to develop short to long‐term strategies based on a holistic assessment of all available energy sources, guiding trends, and delimiting alternatives to expand ...the energy segment. In order to maintain the expansion of the electricity supply system while reducing greenhouse gas emissions, it is essential to use alternative low‐carbon energy sources. The present work aims to use the modeling tool MESSAGE to analyze and evaluate a system of electricity generation from nuclear sources since nuclear energy is an important complementary option for the national energy mix. Thus, this work assesses in an integrated way the national nuclear energy system from its beginning (1983) until 2050. The use of this modeling tool allows a comprehensive analysis of the energy system including energy demand from domestic resources, energy conversion technologies, money flows, investment requirements, and emissions. Therefore, these results provide a basis to support decision‐makers to choose the most appropriate energy mix for national energy planning.
In this paper, an integrated analysis on the Brazilian nuclear energy system allows to evaluate the impacts since the beginning of the nuclear energy use in the country. Past and future impacts on the nuclear fuel cycle, energy matrix, greenhouse gas emissions, and economics are shown providing a basis to support decision‐makers about the use of nuclear energy in the country's energy matrix.
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