997 research outputs found
heat exchanger design and optimization by using genetic algorithm for externally fired micro turbine
Abstract In this study, a new configuration where syngas produced by downdraft gasifier is feed directly in an externally fired air turbine is discussed. Attention was posed towards the critical component of this configuration: the heat exchanger. To achieve acceptable electrical efficiencies, high temperature of the air at the inlet turbine section was imposed. A code for heat exchanger design was built by using MatlabÂź, while the geometrical optimization was performed by using modeFRONTIERÂź by imposing a multi-objective function to maximize the overall heat transfer coefficient and minimize both costs and pressure drops across the equipment
Ready to Use Detector Modules for the NEAT Spectrometer Concept, Design, First Results
The paper presents the detector system developed by Datalist Systems, Ltd. previously ANTE Innovative Technologies for the NEAT II spectrometer at HZB. We present initial concept, design and implementation highlights as well as the first results of measurements such as position resolution. The initial concept called for modular architecture with 416 3He detector tubes organized into thirteen 32 tube modules that can be independently installed and removed to and from the detector vacuum chamber for ease of maintenance. The unalloyed aluminum mechanical support modules for four 8 tube units each also house the air boxes that contain the front end electronics preamplifiers that need to be on atmospheric pressure. The modules have been manufactured and partly assembled in Hungary and then fully assembled and installed on site by Datalist Systems crew. The signal processing and data acquisition solution is based on low time constant 60 ns preamplifier electronics and sampling ADC s running at 50 MS s i.e. a sample every 20 ns for all 832 data channels. The preamplifiers are proprietary, developed specifically for the NEAT spectrometer, while the ADC s and the FPGA s that further process the data are based on National Instruments products. The data acquisition system comprises 26 FPGA modules each serving 16 tubes providing for up to 50 kHz count rate per individual tube and it is organized into two PXI chassis and two data acquisition computers that perform post processing, event classification and provide appropriate preview of the collected data. The data acquisition software based on Event Recording principles provides a single point of contact for the scientific software with an Event Record List with absolute timestamps of 100ns resolution, timing data of 100 ns resolution for the seven discs chopper system as well as classification data that can be used for flexible data filtering in off line analysis of the gathered data. A unique 3 tier system of filtering criteria of events is in operation a hard threshold in the FPGA s to reduce the effect of noise, a pulse shape based classification to eliminate gamma sensitivity and an additional flexible feature based classification to filter out pileup and other unwanted phenomena. This ensures high count rates 50kHz per tube, 1MHz overall while maintaining good quality of measurements e.g. position resolution .The first measurement results show that the delivered detector system meets the initial requirements of 20 mm position resolution along the 2000mm long detector tubes. This is partly due to the innovative event classification system that provides vital pulse shape data that can be used for sophisticated position resolution algorithms implemented on the DAQ computer
Severe Idiopathic Eosinophilic Pneumonia and Vasculitis in 11 Horses
Introduction: Various eosinophilic lesions have been described in horses. Multisystemic eosinophilic epitheliotropic disease (MEED) characterized by eosinophilic granulomas in various organs represents the most diffuse manifestation. In the present study we describe the gross and microscopical lesions of idiopathic eosinophilic pneumonia and vasculitis in 11 horses without systemic involvement.
Materials and Methods: During a 2-year period (2010â2011), lungs from 88 horses with gross signs of pulmonary disease were collected at a slaughterhouse. Lung sections were stained with haematoxylin and eosin, Giemsa and periodic acidâSchiff.
Results: In 11 horses, lungs were enlarged, pale pink and collapsed, with multifocal to coalescing, whiteâred, 0.4â4.0 cm diameter nodules distributed throughout the parenchyma. Histologically, the lesions ranged from severe eosinophilic bronchointerstitial pneumonia to severe eosinophilic lobular bronchopneumonia associated with eosinophilic necrotizing vasculitis affecting small to medium sized vessels. Mild interstitial fibrosis was also present. The other part of the parenchyma appeared emphysematous. There was no histological evidence of parasites within these lesions.
Conclusions: Eosinophilic pneumonia and vasculitis without intralesional parasites are rarely described in horses. Histological findings do not resemble the typical eosinophilic granulomas observed in lungs of horses with MEED, but are similar to the findings in idiopathic chronic eosinophilic pneumonia of man and of ChurgâStrauss syndrome of man
Molecular Profiling of Lymphatic Endothelial Cell Activation In Vitro
The lymphatic vascular system plays a key role in cancer progression. Indeed, the activation of lymphatic endothelial cells (LECs) through the lymphangiogenic process allows for the formation of new lymphatic vessels (LVs) that represent the major route for the dissemination of solid tumors. This process is governed by a plethora of cancer-derived and microevironmental mediators that strictly activate and control specific molecular pathways in LECs. In this work we used an in vitro model of LEC activation to trigger lymphangiogenesis using a mix of recombinant pro-lymphangiogenic factors (VFS) and a co-culture system with human melanoma cells. Both systems efficiently activated LECs, and under these experimental conditions, RNA sequencing was exploited to unveil the transcriptional profile of activated LECs. Our data demonstrate that both recombinant and tumor cell-mediated activation trigger significant molecular pathways associated with endothelial activation, morphogenesis, and cytokine-mediated signaling. In addition, this system provides information on new genes to be further investigated in the lymphangiogenesis process and open the possibility for further exploitation in other tumor contexts where lymphatic dissemination plays a relevant role
VanA type enterococci from humans, animals and food: species distribution, population structure, Tn1546-typing and location, and virulence determinants
VanA-type human (n = 69), animal (n = 49), and food (n =36) glycopeptide-resistant enterococci (GRE)
from different geographic areas were investigated to study their possible reservoirs and transmission routes.
Pulsed-field gel electrophoresis (PFGE) revealed two small genetically related clusters, M39 (n = 4) and M49
(n = 13), representing Enterococcus faecium isolates from animal and human feces and from clinical and fecal
human samples. Multilocus sequence typing showed that both belonged to the epidemic lineage of CC17. purK
allele analysis of 28 selected isolates revealed that type 1 was prevalent in human strains (8/11) and types 6 and
3 (14/15) were prevalent in poultry (animals and meat). One hundred and five of the 154 VanA GRE isolates,
encompassing different species, origins, and PFGE types, were examined for Tn1546 type and location (plasmid
or chromosome) and the incidence of virulence determinants. Hybridization of S1- and I-CeuI-digested total
DNA revealed a plasmid location in 98% of the isolates. Human intestinal and animal E. faecium isolates bore
large (>150 kb) vanA plasmids. Results of PCR-restriction fragment length polymorphism and sequencing
showed the presence of prototype Tn1546 in 80% of strains and the G-to-T mutation at position 8234 in three
human intestinal and two pork E. faecium isolates. There were no significant associations (P > 0.5) between
Tn1546 type and GRE source or enterococcal species. Virulence determinants were detected in all reservoirs
but were significantly more frequent (P < 0.02) among clinical strains. Multiple determinants were found in
clinical and meat Enterococcus faecalis isolates. The presence of indistinguishable vanA elements (mostly
plasmid borne) and virulence determinants in different species and PFGE-diverse populations in the presence
of host-specific purK housekeeping genes suggested that all GRE might be potential reservoirs of resistance
determinants and virulence traits transferable to human-adapted clusters
Understanding the Pathogenesis of Red Mark Syndrome in Rainbow Trout (Oncorhynchus mykiss) through an Integrated Morphological and Molecular Approach
Red mark syndrome (RMS) is a widespread skin disorder of rainbow trout in freshwater aquaculture, believed to be caused by a Midichloria-like organism (MLO). Here, we aimed to study the pathologic mechanisms at the origin of RMS by analyzing field samples from a recent outbreak through gene expression, MLO PCR, quantitative PCR, and a histopathological scoring system proposed for RMS lesions. Statistical analyses included a One-Way Analysis of Variance (ANOVA) with a Dunnettâs multiple comparisons test to assess differences among gene expression groups and a nonparametric Spearman correlation between various categories of skin lesions and PCR results. In short, the results confirmed the presence of a high quantity of 16S gene copy numbers of Midichloria-like organisms in diseased skin tissues. However, the number of Midichloria-like organisms detected was not correlated to the degree of severity of skin disease. Midichloria-like organism DNA was found in the spleen and head kidney. The spleen showed pathologic changes mainly of hyperplastic type, reflecting its direct involvement during infection. The most severe skin lesions were characterized by a high level of inflammatory cytokines sustaining and modulating the severe inflammatory process. IL-1 ÎČ, IL-6, IL-10, MHC-II, and TCR were upregulated in severe skin lesions, while IL-10 was highly expressed in moderate to severe ones. In the moderate form, the response was driven to produce immunoglobulins, which appeared crucial in controlling the skin diseaseâs severity. Altogether our results illustrated a complex immune interaction between the host and Midichloria-like organism
Phytochemical profiling, antibacterial and antioxidant properties of Crocus sativus flower: A comparison between tepals and stigmas
Several studies have demonstrated that stigmas of Crocus sativus contain several bioactive compounds with potential health-promoting properties. However, during the processing of stigmas, large amounts of floral bio-residues are normally discarded as by-products. In this study, using untargeted metabolomics, the comprehensive phytochemical composition of C. sativus stigma and tepals was investigated. Moreover, the antibacterial and anti-biofilm properties of the extracts of C. sativus stigmas and tepals were compared. The study was carried out using two methicillin-resistant staphylococcal reference strains (i.e., Staphylococcus aureus ATCC 43300 and Staphylococcus epidermidis ATCC 35984), representing important Gram-positive biofilm-forming human pathogens. The antibacterial properties were correlated with total polyphenol content, total terpenoid content, and in vitro antioxidant properties of tepals and stigmas. The results demonstrated that stigma and tepal extracts, at the sub-toxic concentrations, were able to interfere with biofilm formation by ATCC 43300 and ATCC 35984. Besides, the higher antibacterial activity of tepals than stigmas was associated with higher levels of phycompounds. Therefore, our results demonstrated that C. sativus stigmas and bio-residues, such as tepals, are potential antioxidant sources and good candidates as antibacterial agents to prevent biofilm formation. Taken together, these findings showed that C. sativus could be used as functional ingredient by the food and pharmaceutical industries
Scintillating fiber devices for particle therapy applications
Particle Therapy (PT) is a radiation therapy technique in which solid tumors are treated with charged ions and exploits the achievable highly localized dose delivery, allowing to spare healthy tissues and organs at risk. The development of a range monitoring technique to be used on-line, during the treatment, capable to reach millimetric precision is considered one of the important steps towards an optimization of the PT efficacy and of the treatment quality. To this aim, charged secondary particles produced in the nuclear interactions between the beam particles and the patient tissues can be exploited. Besides charged secondaries, also neutrons are produced in nuclear interactions. The secondary neutron component might cause an undesired and not negligible dose deposition far away from the tumor region, enhancing the risk of secondary malignant neoplasms that can develop even years after the treatment. An accurate neutron characterization (flux, energy and emission profile) is hence needed for a better evaluation of long-term complications. In this contribution two tracker detectors, both based on scintillating fibers, are presented. The first one, named Dose Profiler (DP), is planned to be used as a beam range monitor in PT treatments with heavy ion beams, exploiting the charged secondary fragments production. The DP is currently under development within the INSIDE (Innovative Solutions for In-beam DosimEtry in hadrontherapy) project. The second one is dedicated to the measurement of the fast and ultrafast neutron component produced in PT treatments, in the framework of the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project. Results of the first calibration tests performed at the Trento Protontherapy center and at CNAO (Italy) are reported, as well as simulation studies
Role of [18F]FDG PET/CT in the management of G1 gastro-entero-pancreatic neuroendocrine tumors
Purpose: Since the role of [18F]FDG PET/CT in low-grade gastroenteropancreatic (GEP) neuroendocrine neoplasia (NET) is not well established, this study was aimed to evaluate the role of [18F]FDG PET/CT in grade 1 (G1) GEP-NETs. Methods: This is a retrospective study including patients with G1 GEP-NETs who underwent [18F]FDG PET/CT. Results: 55 patients were evaluated, including 24 (43.6%) with pancreatic NETs and 31 (56.4%) with gastrointestinal NETs. At the time of diagnosis, 28 (51%) patients had metastatic disease, and 50 (91%) patients were positive by 68-Ga sstr PET/CT. Overall, 27 patients (49%) had positive findings on [18F]FDG PET/CT. Following [18F]FDG PET/CT, therapeutic management was modified in 29 (52.7%) patients. Progression-free survival was longer in patients with negative [18F]FDG PET/CT compared with positive [18F]FDG PET/CT (median PFS was not reached and 24 months, respectively, p = 0.04). This significance was particularly evident in the pancreatic group (p = 0.008). Conclusions: Despite having low proliferative activity, approximately half of GEP-NETs G1 showed positive [18F]FDG PET/CT, with a corresponding negative impact on patientsâ clinical outcomes. These data are in favor of a more âopenâ attitude toward the potential use of [18F]FDG PET/CT in the diagnostic work-up of G1 GEP-NETs, which may be used in selected cases to detect those at higher risk for an unfavorable disease course
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