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Using Finite Element Method (FEM) simulations is possible to study the homogeneity of deformation in the Equal Channel Angular Pressing (ECAP) process. In this work an investigation about the influence of a modified die on strain distribution in an ecaped Al6060 alloy was carried out. Due to that, tensile stress occurs in the vicinity of upper surface of the specimen in the severe plastic deformation zone, which increases the cracking and fracture tendency of the specimen and impedes further ECAP processing, the conventional ECAP die was modified to eliminate the tensile stress and enhance the compressive stress in the severe plastic deformation zone and reducing the cracking and fracture tendency of the specimen. Finite element analysis demonstrated that the stress state changes from tensile to strongly compressive when using the modified die. The aim of this study is to evaluate the advantages/disadvantages of the modified ECAP die and processing conditions.
Cognitive deficits are present from the onset of psychosis and are considered a core feature of the disorder. Increasing evidence suggests that cognitive function is associated with inflammatory processes. This study evaluated the association between cognition and inflammatory biomarkers in first-episode psychosis (FEP), in order to identify cognitive phenotypes from inflammatory expression profiles.
A case-control study of 92 FEP patients and 80 matched controls was used. Neurocognitive assessment, including verbal ability, sustained attention, verbal memory, working memory and executive function, was performed. The expression of pro- and anti-inflammatory mediators of the main intracellular inflammatory pathway was measured in peripheral blood mononuclear cells and plasma.
FEP patients performed worse in all cognitive domains compared to controls and had higher expression of pro-inflammatory mediators and lower expression of anti-inflammatory mediators. In the FEP group, cognition and psychopathology were associated with inflammation. Hierarchical regression analysis showed that association between the anti-inflammatory prostaglandin 15d-PGJ2 and sustained attention on one hand, and COX-2 expression and executive function on the other, were statistically significant.
Our study provides evidence for an association between anti-inflammatory biomarkers and cognition in FEP. The identification of a subgroup of patients based on these measures could be useful to guide treatment programmes by providing tools to select a personalized treatment approach, but longitudinal studies are needed before. In the future, establishment of biomarkers linked to cognition would be useful to monitor the course of cognitive impairment, but substantially more data will be required. Determination of IκBα, the inhibitory protein of the pro-inflammatory transcription factor NFκB, could be useful in early phases to assess clinical severity.
The peritrophic matrix is a chitin-protein structure that envelops the food bolus
in the midgut of the majority of insects, but is absent in some groups which
have, instead, an unusual extra-cellular lipoprotein membrane named the
perimicrovillar membrane. The presence of the perimicrovillar membrane (PMM)
allows these insects to exploit restricted ecological niches during all life
stages. It is found only in some members of the superorder Paraneoptera and many
of these species are of medical and economic importance. In this review we
present an overview of the midgut and the digestive system of insects with an
emphasis on the order Paraneoptera and differences found across phylogenetic
groups. We discuss the importance of the PMM in Hemiptera and the apparent
conservation of this structure among hemipteran groups, suggesting that the
basic mechanism of PMM production is the same for different hemipteran species.
We propose that the PMM is intimately involved in the interaction with parasites
and as such should be a target for biological and chemical control of hemipteran
insects of economic and medical importance.
Understanding the biological parameters of some triatomine subspecies of Meccus phyllosomus (Burmeister) is a crucial first step in estimating the epidemiological importance of this group. Biological parameters related to egg eclosion, egg-to-adult development time, number of blood meals to moult, percentage of females at the end of the cycle, number of laid eggs, and the accumulative mortality for each instar of three M. phyllosomus subspecies [Meccus phyllosomus pallidipennis (Stål), Meccus phyllosomus longipennis (Usinger), and Meccus phyllosomus picturatus (Usinger)] as well as their laboratory hybrids were evaluated and compared. No significant differences (P > 0.05) were recorded among the experimental hybrids (M. p. longipennis × M. p. pallidipennis, M. p. longipennis × M. p. picturatus, M. p. pallidipennis × M. p. picturatus) and reciprocal cohorts. In five of the six studied parameters (egg eclosion, egg-to-adult development time, number of blood meals to moult, number of laid eggs and accumulative mortality), with the exception of the non-significant percentage of females obtained among all the studied cohorts, at least one of the parental cohorts in each set of crosses exhibited better fitness results than by those of their hybrid descendants. The lack of hybrid fitness in our study indicates the maintenance of reproductive isolation of parental genotypes. Moreover, the results lead us to propose that an incipient speciation process by distance is currently developing among the three studied subspecies, increasing the differences between them that modify the transmission efficiency of Trypanosoma cruzi to human beings in Mexico.
Solar irradiance and precipitation are the most likely drivers of the seasonal variation of net primary productivity (NPP) in tropical forests. Since their roles remain poorly understood, we use litter traps, dendrometer bands and census data collected from one hectare permanent plots to quantify the seasonality of above-ground NPP components and weather parameters in 13 sites distributed along a 2800-m altitudinal gradient ranging from lowland Amazonia to the high Andes. We combine canopy leaf area index and litterfall data to describe the seasonality of canopy production. We hypothesize that solar irradiance is the primary driver of canopy phenology in wetter sites, whereas precipitation drives phenology in drier systems. The seasonal rhythm of canopy NPP components is in synchrony with solar irradiance at all altitudes. Leaf litterfall peaks in the late dry season, both in lowland (averaging 0.54 ± 0.08 Mg C ha y−1, n = 5) and montane forests (averaging 0.29 ± 0.04 Mg C ha y−1, n = 8). Peaks in above-ground coarse woody NPP appears to be triggered by the onset of rainfall in seasonal lowland rain forests (averaging 0.26 ± 0.04 Mg C ha y−1, n = 5, in November), but not in montane cloud forests.
Introduction: The diagnosis of trisomy 21 in children has been associated with failed extubation after CHD surgery. Dexmedetomidine may be a useful agent to improve postoperative outcomes in these patients, such as ventilator time, ICU length of stay, or hospital length of stay. Materials and methods: The Pediatric Health Information System database was queried from January, 2008 to December, 2010 for patients with trisomy 21 who underwent CHD surgery. Patients who received dexmedetomidine were matched to patients who did not by propensity score. The primary outcome was ventilator days charged, and secondary outcomes included ICU and hospital length of stay. Results: A total of 1088 patients (544 matched pairs) met inclusion criteria. Patient characteristics were similar, with the exception of more patients in the dexmedetomidine group undergoing repair of complete atrioventricular canal and fewer undergoing mechanical valve replacement (p<0.01). More patients in the dexmedetomidine group were administered milrinone, epinephrine, vasopressin, benzodiazepines, opiates, and adjunct pain and sedative medications (p<0.01). The dexmedetomidine group had greater time on the ventilator [7 (4.5–11) versus 6 (4–10) days (median, interquartile range) p<0.01] and similar ICU length of stay, hospital length of stay, and mortality compared with controls. Mixed-effects modelling clustered on institution did not show beneficial effect of dexmedetomidine on ventilator time, ICU stay, or hospital length of stay. Conclusions: The use of dexmedetomidine was not associated with the decreased ventilatory time. Routine use of dexmedetomidine is not warranted in this patient population.
This study recruited 90 traumatic brain injury (TBI) caregivers from Guadalajara, Mexico to examine influences of five domains of TBI impairment and related caregiver stress on five types of family needs. Canonical correlations suggested that greater social impairment in individuals with TBI and related caregiver stress were associated with higher informational, household and health needs in families. Meanwhile greater physical impairments in individuals with TBI and related caregiver stress were associated with higher household needs. Additionally, greater emotional impairments in individuals with TBI and related caregiver stress were associated with higher informational needs. Caregiver interventions targeting specific TBI impairments and related caregiver stress may meet family needs and thereby improve the quality of informal care for their family members with TBI.
Fine-grained sandstones and siltstones of Late Cretaceous to Eocene age in Antarctica and Tierra del Fuego yield an association of well-known shallow-marine trace fossils. Among them stick out complex spreite burrows, which are formally described as Euflabella n. igen. and subdivided into five ichnospecies with different burrowing programs and occurrences. As shown by concentrations of diatoms, radiolarians, foraminifers, and calcispheres in particular backfill lamellae, the unknown trace makers lived on fresh detritus from the surface as well as the burrowed sediment. In some ichnospecies, vertical sections show that the spreite is three-dimensionally meandering in upward direction and that upper laminae tend to rework the upper backfill of the folds underneath. This could mean a second harvest, after cultivated bacteria had time to ferment refractory sediment components, which the metazoan trace maker had been unable to digest before.
The design and construction of an instrumentation for NOX degradation in a dielectric-barrier discharge reactor (DBDR) is presented. This is endowed with a parallel plane electrode glass-glass (GG) circular geometry configuration. A solid-state multi-cellular power supply was produced in order to generate the plasma discharge. The power supply is based on a full-bridge voltage inverter commanded by three 4.33 kHz square-wave signals. Thus, the output converter signal is filtered by a resonant LC circuit, providing a 13 kHz sine wave to the DBDR. Initial results showing high removal efficiencies of about 97% have been obtained by means of this instrumentation.
A dielectric barrier discharge (DBD) has been successfully applied to studying, both theoretically and experimentally, phenol degradation in waste water aqueous solutions. A coaxial reactor was selected where the liquid waste constitutes a part of the internal electrode itself, the liquid solution flowing up inside the hollow internal electrode impelled by a submersible pump. Thus, the solution falls by gravity on the external surface of the internal electrode. The DBD gas flows in parallel to the surface of the liquid. The cold plasma was generated from Ar-O2 mixture and O2 pure with the inclusion of moisture from the same solution. Two power supplies were compared delivering potentials up to 23 kV at 1.5 kHz, and up to 12 kV at 15.6 kHz respectively. The initial concentration of phenol was around 5 × 10−3 mol/L and efficiencies up to 99% were obtained after 1 h of treatment. Finally, a simplified kinetics model was developed where the temporal evolution of the compounds generated in the phenol degradation process was analyzed. Hydroquinone, catechol and resorcinol were obtained as byproducts and H2O, CO2 and some light carboxylic acids as final products.
An exceptionally well-preserved specimen of Leptochiton sp. attached to a brachiopod valve is described from the early Eocene beds of the La Meseta Formation, Seymour Island. It records the first fossil Polyplacophora from Antarctica. The small specimen has eight imbricating valves, rounded lateral margins, ribs of fine granules, and growth marks in all valves. It strongly resembles extant Antarctic and South American species of Leptochiton Gray. The record of articulate valves in fossil Polyplacophora is rare and requires exceptional preservational conditions. Leptochiton sp. is associated with well preserved bryozoans, brachiopods, asterozoan echinoids, and serpulids, among other organisms that inhabited hard substrates in normal marine conditions, and probably lived attached to the side walls of an incised valley eroded in Cretaceous sediments. The well-preserved fossils were probably removed from their attachment site during storm events and, after a short transportation, rapidly buried within the early Eocene valley-fill deposits. The fossil-bearing beds are included in the Telm 2 or Acantilados Allomember of the La Meseta Formation.
Thermal reduction of PdCo molecular precursors may lead to the controlled production of nanoparticles on high surface area carbon supports that can be used as methanol tolerant oxygen reduction catalysts for direct methanol fuel cells (DMFC). Following this concept, a single molecular precursor source was used for the synthesis of bimetallic nanoparticles on highly oriented pyrolytic graphite (HOPG) and Vulcan (VC) carbon supports. Nanostructural formation of palladium-cobalt on highly ordered pyrolytic graphite (HOPG) was study by AFM, SEM and voltammetry. The relative humidity during precursor deposition was used to control the rings self-formation on HOPG surfaces. Palladium and palladium-cobalt nanoparticles were also formed on high surface area carbon support (Vulcan XC-72R) by thermal reduction and characterized by TEM. The Pd/VC and PdCo/VC nanoparticles were tested for the oxygen reduction reaction (ORR) with and without methanol. The Pd-based catalysts have ORR activity and high methanol tolerance.
We studied the effects of multiwalled carbon nanotubes (MWCNTs) on the Freedericksz transition of a liquid crystal (LC) and calibrated the altitudinal angle of CNTs as a function of the electric field. In addition, we directed the azimuthal angle which gave us complete control of the 3D orientation of the CNTs. We constructed anti-parallel electro-optic cells using a nanocomposite at a concentration of 0.01% CNTs with 4-Cyano-4'-pentylbiphenyl (5CB) liquid crystal. This low concentration was necessary to achieve maximum transmission of electromagnetic radiation through the cell and to minimize the Van der Waals attraction between the CNTs responsible for their aggregation. We chose two dimensional microscopic transmission ellipsometry (2D-MTE) to measure the phaseshift of the polarized electromagnetic radiation through the cell and to derive from it the altitudinal angle of the CNTs. Our results show that in the presence of CNTs the Freedericksz transition occurs at 55% of the transitional electric field as compared to the control electro-optic cell without CNTs. The width of the Freedericksz transition narrows by a similar factor. The switching time of the cell decreased in the presence CNTs by 18.5%.
Neurocysticercosis is a public health problem in many developing countries and is the most frequent parasitic disease of the brain. The human tapeworm carrier is the main risk factor for acquiring neurocysticercosis. Since the parasite lodges only in the human intestine, experimental models of Taenia solium taeniosis have been explored. Macaques, pigs, dogs, cats and rabbits are unsuccessful hosts even in immunodepressed status. By contrast, rodents are adequate hosts since tapeworms with mature, pregravid and, in some cases, gravid proglottids develop after infection. In this review, information that has been generated with experimental models of taeniosis due to T. solium is discussed. Initially, the use of the model for immunodiagnosis of human taeniosis and evaluation of intervention measures is summarized. Next, descriptions of tapeworms and comparison of hamsters, gerbils and other mammals as experimental models are discussed, as well as data on the humoral immune response, the inflammatory reaction and the production of cytokines associated to Th1 and Th2 responses in the intestinal mucosa. Finally, evaluation of protection induced against the development of tapeworms by recombinant T. solium calreticulin in hamsters is summarized and compared to other studies.
Microplasmas are nowadays a powerful tool with multiple
practical applications. The performance of a specific instrumentation for a
plasma needle capable of producing non-thermal plasmas and a DBD reactor
able to produce atmospheric pressure plasmas, both of them designed and
already constructed, is reported. These devices operate at 13.56 MHz and are
driven by a specifically built radio frequency (RF) resonant converter. The
reactors, which operate at atmospheric pressure in a He-air gas mixture at a
1.5 SLPM flow, have been successfully applied to eliminate E. coli bacteria. In the
needle case, bacterial samples were submitted typically to a 500 V peak
voltage plasma discharge for 120 s. In the DBD treatment, the samples were
processed with typical 750 V peak voltage plasma discharges for 80 s. The
sample pH was used as a criterion to measure the effectiveness of the plasma
treatment, in such a way that the return to the basal pH value after the
treatment can be assumed as the validation of the complete bacterial
Female fertility begins to decline many years before menopause, despite continued regular ovulatory cycles. Decreased fecundity with increasing female age has long been recognized in demographic and epidemiological studies. Traditionally, the evaluation of the infertile female consists of: (i) ovulation assessment (ovulatory factors), (ii) evaluation of the uterine morphology (ovulation assessment) and tubal patency (tubal factors), (iii) assessment of the presence of pelvic pathology (by laparoscopy) (peritoneal factors), and (iv) postcoital test (cervical factors). Hysterosalpingography (HSG), laparoscopy are widely used in assessing infertility. Chlamydia antibody testing is a screening method for assessing tubal infertility. HSG, sonohysterography, hystero-salpingo contrast sonography (HyCoSy), magnetic resonance imaging (MRI) and hysteroscopy are used in assessment of uterine factors related to infertility. Currently, the best method to monitor ovulation is transvaginal ultrasound, which can be used to demonstrate the growth of a dominant follicle and provide presumptive evidence of ovulation and leutinization.
We present TCS-CAIN, a NIR survey of the Galactic plane, recently made public at the Instituto de Astrofísica de Canarias, and some results derived from it: with star counts derived directly the structure of the inner the Milky Way can be dissected, obtaining also estimations for the extinction toward the inner MW.