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Nanoparticles of titanium dioxide (TiO2), synthesized by the sonochemical technique, were mixed with different amounts of graphene oxide (GO), obtained by the improved method of Hummer, in order to modify their bandwidth. The TiO2/OG compounds were characterized using different techniques: X-ray Diffraction (XRD), transmission electron microscopy (TEM), Raman and UV-Vis-NIR spectroscopy. TiO2 bandgap decreased, with GO incorporation, from 3.2 to 2.72 eV when GO was present at 20 weigh percentage (TiO2/GO-20%). Photodegradation experiments of methylene blue (MB) were performed with the materials to verify their photocatalytic activity. At 40 minutes, the pure TiO2 degraded 48% of MB, whereas the compound TiO2/GO-20% degraded 88%, showing a good incorporation of both compounds and the improvement of TiO2 photocatalitic properties.
Triatomine bugs carry the parasitic protozoa Trypanosoma cruzi, the causal agent of Chagas disease. It is known that both the parasite and entomopathogenic fungi can decrease bug survival, but the combined effect of both pathogens is not known, which is relevant for biological control purposes. Herein, the survival of the triatomine Meccus pallidipennis (Stal, 1872) was compared when it was coinfected with the fungus Metarhizium anisopliae (Metschnikoff) and T. cruzi, and when both pathogens acted separately. The immune response of the insect was also studied, using phenoloxidase activity in the bug gut and hemolymph, to understand our survival results. Contrary to expectations, triatomine survival was higher in multiple than in single challenges, even though the immune response was lower in cases of multiple infection. We postulate that T. cruzi exerts a protective effect and/or that the insect reduced the resources allocated to defend itself against both pathogens. Based on the present results, the use of M. anisopliae as a control agent should be re-considered.
This research communication addresses the hypothesis that in dual-purpose goats, exposure to 1 h of extra-light given from 16 to 17 h after dawn (pulse of light) in winter stimulates milk yield. One group of goats was maintained under natural short photoperiod (natural day; ND (n = 7)). Another group of lactating females was submitted to an artificial long-day photoperiod consisting of 16 h light and 8 h darkness (long days; LD (n = 7)). A third group of females received one single hour of extra-light 16 h after the fixed dawn (pulse of light; PL (n = 6)). Goats from LD and PL yielded 30% more milk than goats from ND. Mean percentages of fat, protein and lactose contents in milk did not differ between the 3 groups at any stage of lactation, but these components in grams/day were higher in goats from PL than in the others two groups within the first 45 d of lactation. In conclusion, dual-purpose lactating goats that started their lactation during natural short days, the daily exposition to a 1-h pulse of light is sufficient to stimulate milk yield compared to females maintained under natural short photoperiod.
Multiform glioblastoma (MG) represents 70% of all gliomas, with half of patients older than 65 years with median survival of 12–18 months, hypofractionation seeks to reduce the intensity and duration of treatment without impacting on survival rates. The objective was to determine the global survival and recurrence-free survival of adults over 70 years old with MG treated with hypofractionated radiotherapy and standard scheme. The review of patients older than 70 years treated with radiotherapy from 2013 to 2016 was performed.
Twenty-four patients were analysed, with a median follow-up of 239 days, and there is no difference in overall survival 12·3 versus 10·5 months (p = 0·55) and recurrence-free survival 8·3 versus 3·4 months (p = 0·48) between both schemes, conventional versus hypofractioanted, respectively.
The results in this study show that hypofractionated scheme could be comparable in overall survival and recurrence-free survival to conventional fractionation, but a longer patients’ trial should be done.
OBJECTIVES/SPECIFIC AIMS: The Title V Cooperative Project of the UPR-MSC and UCC has demonstrated that educational interventions in CTR are very effective in fulfilling the objective of promoting awareness, stimulate interest and increase the knowledge, skills and opportunities, to US, GS and F (participants) in CTR. METHODS/STUDY POPULATION: The training sessions (TS) offered through the Title V initiative have become an engine for the involvement in CTR for participants from higher education institutions island-wide. TS consisted of cycles –level 1 and 2–: Research Education Towards Opportunities (RETO,I,II) and Mentorship Offering Training Opportunities for Research (MOTOR,I,II), ending in the formation of the Clinical and Translational Mentoring Teams (CTMT)s, in which participants, paired by their research interests, were mentored by a well-established CT researchers in their research project, to be developed in the Intensive Development and Experiences in Advancement of Research and Increased Opportunities (IDEARIO). RESULTS/ANTICIPATED RESULTS: Up to date, 4 TS-level 1 and 2 TS-level 2 were offered. Eighty (80) participants completed level 1, distributed: 42 (52.5%) US in RETO, 21 (26.25%) GS and 17 (21.25%) F in MOTOR and 17 participants completed level 2, distributed: 4 (23.52%) US in RETO, 6 (25.29%) GS and 7 (41.17%) F in MOTOR. From which, 15, with 8 CT researchers, formed 5 CTMTs in different research areas – cardio, neuro, liver, renal, Zika–. DISCUSSION/SIGNIFICANCE OF IMPACT: US, GS and F were integrated in the active process throughout educational levels for their development in CTR.
This study analyzes the relationship between the two intrapersonal perfectionism dimensions (i.e., Self-Oriented Perfectionism-Critical, SOP-C, and Self-Oriented Perfectionism-Strivings, SOP-S) and the components of aggressive behavior (cognitive, emotional and motor) in a sample of 804 (48.3% females) Spanish students between the ages of 8 and 11 (M = 9.57; DE = 1.12). The Spanish versions of the SOP-C and SOP-S subscales of the Child/Adolescent Perfectionism Scale and the Aggression Questionnaire were used. Students with high SOP-C scored significantly higher (p < .001) than their peers with low SOP-C on all components of aggressive behavior. The magnitude of these differences (Cohen’s d index) ranged from .40 to .59. In contrast, non-significant statistical differences were found between students with high and low SOP-S. Moreover, logistic regression analysis revealed that SOP-C significantly and positively predicted high Hostility, Anger and Physical and Verbal Aggression, whereas none of these components were significantly predicted by SOP-S (95% CI). Results are discussed, taking into account the debate on the conceptualization and nature of intrapersonal perfectionism.
We assessed inter-seasonal dynamics of seed banks, dormancy and seed germination in three endemic Chihuahuan Desert succulent species, under simulated soil warming conditions. Hexagonal open top-chambers (OTCs) were used to increase soil temperature. Seeds of Echinocactus platyacanthus (Cactaceae), Yucca filifera and Agave striata (Asparagaceae) were collected and buried within and outside OTCs. During the course of one year, at the end of each season, seed batches were exhumed to test viability and germination. Soil temperature in OTCs was higher than in control plots. Yucca filifera seeds always had high germination independently of warming treatment and season. Agave striata seeds from OTCs had higher germination than those from control plots. Agave striata exhibited low germination in fresh seeds, but high germination in spring. Seeds from this species lost viability throughout the experimental timeframe, and had no viable seeds remaining in the soil. Echinocactus platyacanthus showed high germination in fresh seeds and displayed dormancy cycling, leading to high germination in spring, low germination in summer and autumn, and high germination in winter. Germination of this species was also higher in seeds from OTCs than those from control plots. Echinocactus platyacanthus formed soil seed banks and its cycle of inter-seasonal dormancy/germination could be an efficient physiological mechanism in a climate change scenario. Under global warming projections, our results suggest that future temperatures may still fall within the three studied species’ thermal germination range. However, higher germination for A. striata and E. platyacanthus at warmer temperatures may reduce the number of seeds retained in the seed bank, and this could be interpreted as limiting their ability to spread risk over time. This is the first experimental study projecting an increase in soil temperature to assess population traits of succulent plants under a climate change scenario for American deserts.
Composites from carbon nanotubes and polymers have been synthesized and studied. The composites were obtained joining carbon nanotubes with polymethyl methacrylate, nylon-6 and polystyrene. The materials were observed through scanning electron microscopy to evaluate the carbon nanotubes dispersion in the polymeric matrices. FTIR and Raman spectroscopies were used to analyze the interactions among functionalized and non-functionalized multiwalled carbon nanotubes and polymers, demonstrating affinity and peculiar spectra behaviors for each composite with different carbon nanotubes loads.
PA6 and PMMA polymers with different MWCNTs addition (5, 7 and 9 wt %) were synthetized through casting solution, resulting in improvement properties in contrast to pristine polymers. SEM images showed the MWCNTs embedded into polymeric matrices. D, G and G´ bands of MWCNTs were confirmed by Raman spectroscopy and functional groups observed in both nanocomposites by FTIR demonstrated a strong interaction. A significant increasing in electrical conductivity and microhardness was observed in all the nanocomposites. Major microhardness values were obtained in MWCNTs/PA6 (50 HV) however the MWCNTs/PMMA nanocomposites showed the highest electrical conductivity value (6.4×10-4 S/cm).
The non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory of irreversible processes in liquids has been proposed as a theoretical framework capable of predicting the age- and preparation-dependent properties of highly ubiquitous non-equilibrium amorphous solids, such as like glasses and gels. By this formalism, we discuss the main kinetic features of the irreversible relaxation of simple liquids involved in the arrested spinodal decomposition of suddenly and deeply quenched. At some lower temperature we identify, by means of a latency time within which particles retain a finite apparently stationary mobility, the crossover from full phase separation to arrested spinodal decomposition which leads to recognize the onset of gelation.
Endemic insular species are particularly vulnerable to anthropogenic threats. The fish-eating bat Myotis vivesi is restricted mainly to the islands of the Gulf of California in Mexico and although several aspects of its biology have been studied there are no recent accounts of its current distribution. We conducted several expeditions during 2001–2016 to verify the current geographical distribution of this bat, and to record the presence of introduced predators. We identified the localities in which maternity colonies occur, estimated the size of the bat population on Partida Norte Island in 2003, and monitored bat presence on this island during 2004–2016. We found fish-eating bats on 36 islands and maternity colonies on 19 islands. Introduced rats Rattus rattus or cats Felis catus were captured on seven islands where the bats were present, and on five islands where they were absent. We estimated a population of c. 30,000 fish-eating bats in May 2003 and we confirmed the species’ presence on Partida Norte Island during 2004–2016. Based on the information compiled from our surveys and previous studies, we discuss the adequacy of the species’ current categorization as Vulnerable on the IUCN Red List, and its conservation status conferred by Mexican conservation authorities.
The aim of this research is to ameliorate the dispersion of pristine and functionalized Carbon Nanotubes (CNTs) into polystyrene with hydroxyl end groups (PSOH) matrices using low magnetic fields. The Multi-Walled Carbon Nanotubes (MWCNTs) were synthesized by chemical vapor deposition (CVD) using benzene as carbon source; to produce CNTs with and without functional groups two catalysts were used (stainless steel and ferrocene). The obtained nanotubes contained iron nanoparticles inside. PSOH were synthesized using styrene as monomer, azobisisobutyronitrile as initiator and 2-MeOH as chain transfer agent. The MWCNTs-PSOH matrices were formed using 1.6 wt % of carbon nanotubes into PSOH and ultrasonic mixing for 30 min. The mixing materials were poured into containers and dry at room temperature. While the material was drying, constant magnetic fields of 0.24 T were being applied for 50 min. The MWCNTs-PSOH composites were analysed by SEM, FTIR and Raman spectroscopy. SEM micrographs showed that MWCNTs without functional groups were incorporated in the middle of PSOH. The MWCNTs functionalized perform differently; a better dispersion through the entire polymer matrix was achieved, because the polymer embedded the CNTs. FTIR and Raman spectroscopy showed chemical interaction between PSOH and MWCNTs functionalized. The CNTs dispersion into PSOH was ameliorated through the use of low magnetic fields and functionalization.
The cattle tick Rhipicephalus (Boophilus) microplus is a hematophagous ectoparasite of major importance for the livestock industry. It shows a remarkable ability to survive over long periods without feeding. However, the mechanisms used to endure long-term starvation are poorly understood. It is believed that autophagy, a process of intracellular protein degradation, may play a significant role to confront adverse environmental conditions. To advance our understanding of autophagy in R. microplus, in the present study we report the molecular characterization of three autophagy-related (ATG) genes, namely, RmATG3, RmATG4 and RmATG6, as well as their expression profiles in different developmental stages and organs of the parasite. The deduced amino acid sequences derived from the characterized gene sequences were subjected to Basic Local Alignment Search Tool analysis. The testing produced significant alignments with respective ATG proteins from Haemaphysalis longicornis and Ixodes scapularis ticks. Real-time polymerase chain reaction assays revealed that RmATG4 and RmATG6 transcripts were elevated in egg and ovary tissue, when compared with larva and midgut samples, while RmATG3 expression in midgut was 2-fold higher than in egg, larva and ovary samples.
Chitin nanowhiskers were obtained with the purpose to be used as astaxanthin protectors against the photo and thermal degradation. These nanostructures were generated by a freezing/thawing procedure using two stirring methods: mechanical and sonication, which were named as FTM and FTS respectively. Morphological and spectroscopic studies were carried out on chitin nanowhiskers by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Through a SEM analysis, chitin fibers were found uniformly spaced and oriented with the width ranged from of 20-40 nm. Furthermore, the nanowhiskers obtained by FTM showed long and flattened structures and bundles of homogeneous sizes, which have the capacity of being sites of stress concentration. In contrast, by FTS, the nanowhiskers showed coarse fibers exhibiting numerous peaks. By comparing the two methods is appreciated that FTS method provides more surface area, giving more sites for functionalization. Fourier transform infrared spectroscopy (FTIR) allowed the determination of free movement of functional groups on the surface of samples obtained by FTM and FTS methods. Significant differences of signals in the spectra indicate that there were more unassociated amides in the nanowhiskers obtained by FTS than by FTM.
Aluminum titanium oxynitride (TiAlNO) coatings were deposited on 316 steel substrates by the sputtering technique, varying the nitrogen flow from 2.5, 5, 7.5 to 10 sccm, and maintaining constant at 12 sccm the flow argon gas. We used targets of titanium and alumina with 99.995% purity. The hardness and tribological analyses were determined by Vickers microhardness and tribology (tribometer pin-disc), respectively. The results show that the coating with a nitrogen flow of 10 sccm had the lowest volumetric wear (2.047738693 mm3) and the maximum value of hardness (11.2 GPa). Analysis of X-ray diffraction evidenced the presence of three crystalline phases: Ti2N, Al2O3 and TiO2. It can be observed that by increasing the nitrogen flow, the portion of semi-Ti2N phase increases, Al2O3 decreases and TiO2 remains almost constant, and also producing a change in crystallographic orientation with reference to the Ti2N phase. Crystal grain sizes were estimated by X-ray diffraction Fourier line profile analysis using Warren–Averbach method. This analysis showed a grain size between 5 and 15 nm. Raman spectroscopy results show the presence of the TiO2 phase which corroborated the X-ray diffraction results.
Carbon nanotubes (CNTs) were synthesized by Chemical Vapor Deposition (CVD) from diethyl ether, butanol, hexane and ethyl acetate. A quartz tube with a stainless steel tube catalyst core with 0.019 m diameter and 0.6 m large formed the reactor. To avoid combustion, argon was used as the carrier gas. Time process ranged 30 to 60 min. The range of CNTs synthesis temperature was 680-850 °C for different precursors. Scanning Electron Microscopy micrographs have demonstrated tangled CNTs growth in all samples, thus presenting difficult length measurement. The CNTs diameters from diethyl ether are 45-200 nm, butanol diameter range from 55-230 nm, hexane diameter range is 50-130 nm and ethyl acetate range from 100 to 300 nm. Carbon content for all samples was higher than 93 %, CNTs from butanol showed carbon concentration up to 99%. FTIR, Raman and X-Ray Spectroscopies spectra for all samples demonstrated the characteristics signals present in carbon nanotubes. This research proposes a simple, effective and innovative method to synthesize CNTs by CVD on iron stainless steel catalyst in combination with diethyl ether, ethyl acetate, butanol and hexane as precursors by applying the principles of green chemistry, sustainability and its ease to be scaled.
Chitosan is biocompatible polymer has a great commercial interest because it can be processed in a sort of devices varying in shape and size, such as membranes, gels and nanoparticles. Mostly, the cell’s attachment and proliferation are very positive on nanostructurated materials with a three-dimensional formation. An irreversible network can be produced by covalently binding the polymer to the cross-linker molecules. Chitosan nanoparticles were prepared using glutaraldehyde as cross-linker. This crosss-liker mostly reacts with chitosan amino groups. In order to control and understand the physical characteristics of chitosan nanoparticle, in this work is showed the molecular behavior of chitosan/glutaraldehyde from the viewpoint of molecular interactions base in a series of molecular dynamics (MD) computer simulation. The results indicated the conformations of both molecules, which had a significant influence on the molecular association. The chitosan chains were uniformly distributed presenting a high flexibility and preference for the relaxed two-fold helix. This was due to the various associations such as intramolecular chitosan interactions –O-H···O-C-. While the chitosan-glutaraldehyde associations were due to the positive net charge density of hydrogens in the chitosan plus - H2N···C=O associations. In solid state chitosan nano and microparticles were analyzed by scanning electron microscopy (SEM). According to the micrographs results, the nanoparticles presented a monomorphism with piles of particles arranged in linear order which was consistent with the conformations determined by simulation.
In this work, the annealing effects at 180°C in Aluminum-ZnO contacts as function of time were studied. Also, the application in TFTs of ZnO films obtained at low-temperature (200°C) are presented. The ZnO films obtained by ultrasonic Spray Pyrolysis at 200 °C were deposited over Aluminum contacts on SiO2/Si wafers to demonstrate the use of active layer in thin-film transistors. The results show that an improvement can be obtained in metal-ZnO interfaces by low-temperature annealing treatments. However, long annealing time degrade the metal-ZnO interface and may affect the electrical performance of the device.
The cephalopods from Union y Progreso represent the first fossil assemblage described from the Parras Shale in Coahuila, Mexico. Pseudoschloenbachia (Pseudoschloenbachia) aff. P. (P.) mexicana (Renz, 1936), P. (P.) mexicana (Renz, 1936), Baculites haresi Reeside, 1927, and Menabites (Delawarella) vanuxemi (Morton, 1830) have a geographically restricted occurrence. Didymoceras juv. sp., Menuites juv. sp., Polyptychoceras juv. sp., Pseudoxybeloceras (Parasolenoceras) juv. sp., and Scaphites sp. ex gr. S. hippocrepis (DeKay, 1828) are represented by juveniles and could not be determined to species level. Desmophyllites diphylloides (Forbes, 1846) is the only long-ranging, cosmopolitan species described from this assemblage. Three new species are described: Eutrephoceras irritilasi n. sp., Hypophylloceras (Neophylloceras) arturoi n. sp., and Tetragonites silencioensis n. sp. The morphotype Baculites n. sp. is also inferred to be distinct. The faunal composition of this assemblage indicates a late early Campanian age. This assemblage shows a high degree of endemism. The causes for this endemism are currently unknown and difficult to assess. Nevertheless, the generic composition of the Union y Progreso ammonite assemblage suggests a short-term early Campanian endemic event.
During several months in 2010, a very peculiar story dominated global news, culminating in 24-hour coverage October 12–14. Trapped for several months and at one point presumed dead, 33 Chilean miners were rescued on global TV. The narrative arc of the rescue was a typical media spectacle of fortitude, technological know-how, and human dignity, topped off by incredible success. From the beginning, the Chilean story took on a nationalistic air. When the miners were discovered alive, their first spoken message to the world was the Chilean national anthem sung in unison. From that day onward, there were scantily few images of the site and the rescue process that did not include a Chilean flag.
For audiences in many parts of the world, the conjunction of tragedy, triumph, and jingoistic celebration would appear perfectly normal, and very much in line with similar events such as the 9/11and 7/7 terrorist attacks. What could be more typical than an expression of national solidarity in the face of a common threat? Yet for many Latin American observers, the Chilean response seemed somewhat odd. In fact, in country after country in the region, common threats do not soothe internal divisions, but actually seem to deepen them. One could have imagined many other political narratives in the region accompanying the original accident and subsequent rescue focusing on class divisions, regional complaints, or ethnic claims; to stand with the miners as workers is one thing, to stand with them as co-nationals is another. The very exceptionalism of the way Chileans came together behind their government during the mine rescue highlights the particular nature of state–society relations in much of Latin America and serves to bring forth a series of questions about nationalist sentiment in the region. Two issues deserve special attention: first, what is the nature of Latin American nationalism and, second, how does its development correspond to the kind of stimuli associated with it in other parts of the world? The first can help us to understand the specific region better, while the second might improve our analysis of the process of state and nation making throughout the developing world.