2,988 research outputs found

    Compositional uniformity, domain patterning and the mechanism underlying nano-chessboard arrays

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    We propose that systems exhibiting compositional patterning at the nanoscale, so far assumed to be due to some kind of ordered phase segregation, can be understood instead in terms of coherent, single phase ordering of minority motifs, caused by some constrained drive for uniformity. The essential features of this type of arrangements can be reproduced using a superspace construction typical of uniformity-driven orderings, which only requires the knowledge of the modulation vectors observed in the diffraction patterns. The idea is discussed in terms of a simple two dimensional lattice-gas model that simulates a binary system in which the dilution of the minority component is favored. This simple model already exhibits a hierarchy of arrangements similar to the experimentally observed nano-chessboard and nano-diamond patterns, which are described as occupational modulated structures with two independent modulation wave vectors and simple step-like occupation modulation functions.Comment: Preprint. 11 pages, 11 figure

    Effects of types and doses of yeast on gas production and in vitro digestibility of diets containing maize (Zea mays) and lucerne (Medicago sativa) or oat hay

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    Two yeast products formulated with Saccharomyces cerevisiae were evaluated at the same colonyforming units (CFUs) per gram of substrate. Samples of maize, lucerne and oat hays were mixed (0.5 kg) to a proportion of 80% forage (lucerne or oat) with 20% maize (DM basis) and combined with each yeast to obtain 1.5 x 107 or 3.0 x 107 CFU/g DM. There was also a control without yeast. In vitro gas production was measured at 0, 2, 4, 6, 8, 10, 14, 18, 24, 30, 36, 42, 48, 60, and 72 h incubation. There was no forage/yeast interaction. Both yeast products tended to reduce the maximum volume produced quadratically and lag time linearly, while in vitro dry matter digestibility (IVDMD) increased linearly. Ruminal ammonia N and lactic acid were not affected, whereas methane and carbon dioxide tended to be reduced with the intermediate dose of yeast. When the mixture included oat hay, the total volume of gas increased, the lag time decreased, and there was higher IVDMD than in the lucerne-based mixtures, which were associated with lower methane production. Ammonia and lactic acid remained unchanged. The two yeast products showed the same effects on the dynamics of gas production and in vitro digestibility when dosed at the same number of viable cells or CFUs, and there was no interaction with forage quality

    Preparation and characterization of a tumor-targeting dual-image system based on iron oxide nanoparticles functionalized with folic acid and rhodamine

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    Cancer is one of the diseases with most deaths worldwide, around 8.2 million annually. For this reason, several treatments and diagnostic tools have been investigated and developed over the past decades. Among them, a dual-image system has been developed to achieve and enhance the detection of cancer, which has not been done with systems currently available. The present study describes the preparation of a dual-image targeting system composed of magnetic iron oxide nanoparticles functionalized with folic acid and rhodamine; nanoparticles synthesis was achieved by a coprecipitation method; the functionalization was carried out by a carbodiimide with folic acid and/or the rhodamine isothiocyanate; conjugates were characterized by spectrometric techniques; toxicity was measured by cell proliferation assay on HeLa cells using progressive concentrations of functionalized nanoparticles. Cellular uptake assay was carried out by competitive assay on HeLa cells. Iron oxide magnetite nanoparticles, modified with folic acid and rhodamine, were successfully synthetized with a particle size lower than 20nm (TEM), EDS, HRTEM, and XDR showed highly crystalline Fe3O4 nanoparticles. Folic acid and rhodamine were conjugated with high efficiency. A significant selectivity and uptake, facilitated by surface modification of iron oxide nanoparticles with folic acid, were demonstrated.The multifunctional system showed suitable physicochemical and biological properties for cell targeting through folate receptors.This study was supported by the International Atomic Energy Agency (CRP-F22064, Contract no. 18358) and the Universidad Autónoma del Estado de México, through Project no. 3543/2013CHT

    Interannual variability of the early summer circulation around the Balearic Islands: driving factors and potential effects on the marine ecosystem

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    Six summer surveys conducted from 2001 to 2005 and in 2012 by the Spanish Institute of Oceanography (IEO) reveal that the hydrographic early summer scenarios around the Balearic Islands are related to the winter atmospheric forcing in the northwestern Mediterranean Sea. The Balearic Islands (western Mediterranean Sea) lie at the transition between the southern, fresher, newly arrived Atlantic Waters (AW) and the northern, saltier, resident AW. The meridional position of the salinity driven oceanic density front separating the new from the resident AW is determined by the presence/absence of Western Intermediate Water (WIW) in the Mallorca and Ibiza channels. When WIW is present in the channels, the oceanic density front is found either at the south of the islands, or along the Emil Boudot escarpment. In contrast, when WIW is absent, new AW progresses northwards crossing the Ibiza channel and/or the Mallorca channel. In this later scenario, the oceanic density front is closer to the Balearic Islands. A good correspondence exists between standardized winter air temperature anomaly in the Gulf ofLions and the presence of WIW in the channels. We discuss the use of a regional climatic index based on these parameters to forecast in a first-order approach the position of the oceanic front, as it is expected to have high impact on the regional marine ecosystem.Post-print

    Financial cost of the admissions for simultaneous pancreas-kidney transplant in a Brazilian Hospital

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    PURPOSE:To perform a cost analysis of simultaneous pancreas-kidney transplantation (SPKT) in a Brazilian hospital.METHODS:Between January 2008 and December 2011, 105 consecutive SPKTs at the Hospital of Kidney and Hypertension in São Paulo were evaluated. We evaluated the patient demographics, payment source (public health system or supplementary system), and the impact of each hospital cost component. The evaluated costs were corrected to December 2011 values and converted to US dollars.RESULTS:Of the 105 SPKT patients, 61.9% were men, and 38.1% were women. Eight patients died, and 97 were discharged (92.4%). Eighty-nine procedures were funded by the public health system. The cost for the patients who were discharged was 18.352.27;thecostforthedeceasedpatientswas18.352.27; the cost for the deceased patients was 18.449.96 (p = 0.79). The FOR for SPKT during this period was positive at $5,620.65. The costs were distributed as follows: supplies, 36%; administrative costs, 20%; physician fees, 15%; intensive care unit, 10%; surgical center, 10%; ward, 9%.CONCLUSION:Mortality did not affect costs, and supplies were the largest cost component.Federal University of São Paulo Department of SurgeryUniversidade Federal de São Paulo (UNIFESP) Department of SurgeryHypertension and Kidney HospitalUniversidade Federal de São Paulo (UNIFESP) Department of Internal MedicineUniversidade Federal de São Paulo (UNIFESP) Department of PediatricUNIFESP, Department of SurgeryUNIFESP, Department of SurgeryUNIFESP, Department of Internal MedicineUNIFESP, Department of PediatricSciEL

    Coxiella endosymbiont of Rhipicephalus microplus modulates tick physiology with a major impact in blood feeding capacity

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    In the past decade, metagenomics studies exploring tick microbiota have revealed widespread interactions between bacteria and arthropods, including symbiotic interactions. Functional studies showed that obligate endosymbionts contribute to tick biology, affecting reproductive fitness and molting. Understanding the molecular basis of the interaction between ticks and their mutualist endosymbionts may help to develop control methods based on microbiome manipulation. Previously, we showed that Rhipicephalus microplus larvae with reduced levels of Coxiella endosymbiont of R. microplus (CERM) were arrested at the metanymph life stage (partially engorged nymph) and did not molt into adults. In this study, we performed a transcriptomic differential analysis of the R. microplus metanymph in the presence and absence of its mutualist endosymbiont. The lack of CERM resulted in an altered expression profile of transcripts from several functional categories. Gene products such as DA-P36, protease inhibitors, metalloproteases, and evasins, which are involved in blood feeding capacity, were underexpressed in CERM-free metanymphs. Disregulation in genes related to extracellular matrix remodeling was also observed in the absence of the symbiont. Taken together, the observed alterations in gene expression may explain the blockage of development at the metanymph stage and reveal a novel physiological aspect of the symbiont-tick-vertebrate host interaction

    Outcomes of abdominal wall reconstruction in patients with the combination of complex midline and lateral incisional hernias.

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    Background The best treatment for the combined defects of midline and lateral incisional hernia is not known. The aim of our multicenter study was to evaluate the operative and patient-reported outcomes using a modified posterior component separation in patients who present with the combination of midline and lateral incisional hernia. Methods We identified patients from a prospective, multicenter database who underwent operative repairs of a midline and lateral incisional hernia at 4 centers with minimum 2-year follow-up. Hernias were divided into a main hernia based on the larger size and associated abdominal wall hernias. Outcomes reported were short- and long-term complications, including recurrence, pain, and bulging. Quality of life was assessed with the European Registry for Abdominal Wall Hernias Quality of Life score. Results Fifty-eight patients were identified. Almost 70% of patients presented with a midline defect as the main incisional hernia. The operative technique was a transversus abdominis release in 26 patients (45%), a modification of transversus abdominis release 27 (47%), a reverse transversus abdominis release in 3 (5%), and a primary, lateral retromuscular preperitoneal approach in 2 (3%). Surgical site occurrences occurred in 22 patients (38%), with only 8 patients (14%) requiring procedural intervention. During a mean follow-up of 30.1 ± 14.4 months, 2 (3%) cases of recurrence were diagnosed and required reoperation. There were also 4 (7%) patients with asymptomatic but visible bulging. The European Registry for Abdominal Wall Hernias Quality of Life score showed a statistically significant decrease in the 3 domains (pain, restriction, and cosmetic) in the postoperative score compared with the preoperative score. Conclusion The different techniques of posterior component separation in the treatment of combined midline and lateral incisional hernia show acceptable results, despite the associated high complexity. Patient-reported outcomes after measurement of the European Registry for Abdominal Wall Hernias Quality of Life score demonstrated a clinically important improvement in quality of life and pain.post-print2.323 K

    Influence of dietary fiber upon in vitro microbial cecal fermentation in mexican hairless and mexican cuino pigs

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    The objective of the present study was to evaluate and compare the in vitro cecal fermentation (by the gas production technique), in Mexican hairless pig (MHP) and Mexican cuino pig (MCP), adding cellulose or starch as substrates (0, 100, 200, 300 and 400 mg/g DM). 12 pigs were slaughtered (BW= 104±0.5 kg), six of each genotype were collected from the cecal contents and there was a pool for every two pigs in each genotype, and thereafter, for each substrate (cellulose or starch) in its different concentration, three flasks were incubated with inoculum for each pool and made three series of incubation. The experimental design use the effect of genotype, substrate and concentration of the substrate added on the variables of in vitro fermentation. The averages of the data were compared by Tukey's method. In vitro gas production was higher (P<0.05) (mL/g DM) for MHP (206.8) vs MCP (180.2). The degradation fractional rate rhythm (b, 0.094 and c, -0.0127) and lag time (1.79) of the MHP was higher than MCP (b, 0.074; c -0.102) and lag time (1.26); with the addition of carbohydrates as substrates, in vitro gas production of potato starch was higher (P<0.05) than cellulose (238.3 vs 148.7 mL/g DM); the fractions b, c and lag time, there were differences (P<0.05) between substrates. The increasing addition of cellulose or starch had a lineal effect (P<0.05) with the gas production, level cero mg (133.46) to 400 mg of substrate (263.16 mL/g DM). MHP had a higher cecal fermentation than MCP, being higher the gas production at 9 and 12 h, there was higher gas production (cecal fermentation) when added starch as substrate

    Accurate quantification of atherosclerotic plaque volume by 3D vascular ultrasound using the volumetric linear array method.

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    Direct quantification of atherosclerotic plaque volume by three-dimensional vascular ultrasound (3DVUS) is more reproducible than 2DUS-based three-dimensional (2D/3D) techniques that generate pseudo-3D volumes from summed 2D plaque areas; however, its accuracy has not been reported. We aimed to determine 3DVUS accuracy for plaque volume measurement with special emphasis on small plaques (a hallmark of early atherosclerosis). The in vitro study consisted of nine phantoms of different volumes (small and medium-large) embedded at variable distances from the surface (superficial vs. >5 cm-depth) and comparison of 3DVUS data generated using a novel volumetric-linear array method with the real phantom volumes. The in vivo study was undertaken in a rabbit model of atherosclerosis in which 3DVUS and 2D/3D volume measurements were correlated against gold-standard histological measurements. In the in vitro setting, there was a strong correlation between 3DVUS measures and real phantom volume both for small (3.0-64.5 mm(3) size) and medium-large (91.1-965.5 mm(3) size) phantoms embedded superficially, with intraclass correlation coefficients (ICC) of 0.99 and 0.98, respectively; conversely, when phantoms were placed at >5 cm, the correlation was only moderate (ICC = 0.67). In the in vivo setting there was strong correlation between 3DVUS-measured plaque volumes and the histological gold-standard (ICC = 0.99 [4.02-92.5 mm(3) size]). Conversely, the correlation between 2D/3D values and the histological gold standard (sum of plaque areas) was weaker (ICC = 0.87 [49-520 mm(2) size]), with large dispersion of the differences between measurements in Bland-Altman plots (mean error, 79.2 mm(2)). 3DVUS using the volumetric-linear array method accurately measures plaque volumes, including those of small plaques. Measurements are more accurate for superficial arterial territories than for deep territories.S
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