Disorder Analysis in Infrared Spectroscopy of Acetylene Ice.

A new method to investigate disorder in ice films is proposed and applied to acetylene ice. It is based on a quantitative analysis of the infrared spectrum data, which includes: the Brendel-Bormann model for the material's dielectric function; molecular vibration modes calculated by density functional theory (DFT); a monomer-dimer model for amorphous ice; and a peak-shape analysis through Levenberg-Marquardt nonlinear regression. Acetylene ice films with different degrees of disorder were investigated with the proposed method. The results provide an estimate of the degree of disorder in the films and indicate the possibility of existence of a second amorphous phase of acetylene ice grown at temperatures of about 15 K and then annealed. This phase would be similar to the high-density amorphous phase observed for water ice. The infrared data in this work is compared with those from the literature for acetylene gas, acetylene film, and acetylene aerosol. A qualitative analysis reveals differences in the degree of disorder in each system and points to a crystallinity limit for acetylene ice film; that is, the crystalline acetylene film has a higher degree of intrinsic disorder than the crystalline acetylene aerosol.

Organic fertilization influences nematode diversity and maturity index in coffee tree plantations using an agroforestry system.

In conventional coffee farming, soil fauna can be negatively affected by the intensive management practices adopted and the use of an agroforestry system (AFS) is an alternative to reduce these impacts. In coffee AFS, soil nutrition is provided mainly using organic fertilizers. This soil management favors the microbiota and can alter the population dynamics of some organisms. Our objective was to evaluate the effect of organic fertilizers on the nematode community in coffee AFS and to determine their impact on soil ecology. Soil samples were collected from three coffee AFS and a nearby Atlantic rainforest fragment. Nematodes were extracted from the samples and identified to the genus. The identified populations were compared using several community and diversity indices to determine the environmental conditions of the systems under evaluation. No differences in total abundance among nematode communities were found in the four areas evaluated. Regarding trophic groups, the coffee AFS treated with either cow manure or poultry litter favored the trophic group of bacterivores. Plant-parasitic nematodes were more abundant in soils of both the naturally fertilized coffee AFS and the Atlantic rainforest fragment. The maturity and structural indexes indicated that the Atlantic rainforest fragment and the naturally fertilized coffee AFS had similar ecological functions. On the other hand, soils fertilized with cow manure were less diverse, had higher dominance in the community, and showed less ecological stability. The nematode communities found in the AFS were similar to those seen in the forest fragment indicating that is possible to produce coffee sustainably without negatively affecting soil quality.

Utilization of temporal dominance of sensations and time intensity methodology for development of low-sodium Mozzarella cheese using a mixture of salts.

Evidence has linked excessive salt consumption to the development of chronic degenerative diseases. Therefore, special attention has been given to the consumption of healthier products with reduced sodium contents. This study aimed to develop a Mozzarella cheese with a reduced sodium content using a mixture of salts through acceptance testing and temporal sensory evaluation. The following 3 formulations of Mozzarella cheese were prepared: formulation A (control), which was produced only with NaCl (0% sodium reduction), formulation B (30% sodium reduction), and formulation C (54% sodium reduction). Every formulation was produced using a mixture of salts consisting of NaCl, KCl, and monosodium glutamate at different concentrations. The products underwent sensory acceptance tests, and the time intensity and temporal dominance of sensations were evaluated. The proportions of salts used did not cause strange or bad tastes but did result in lower intensities of saltiness. Mozzarella with low sodium content (B and C) had a sensory acceptance similar to that of traditional Mozzarella (A). Therefore, the use of a mixture of salts consisting of NaCl, KCl, and monosodium glutamate is a viable alternative for the production of Mozzarella, with up to a 54% reduction in the sodium content while still maintaining acceptable sensory quality.

Biodegradation of porous calcium phosphate scaffolds in an ectopic bone formation model studied by X-ray computed microtomograph.

Three types of ceramic scaffolds with different composition and structure [namely synthetic 100% hydroxyapatite (HA; Engipore), synthetic calcium phosphate multiphase biomaterial containing 67% silicon stabilized tricalcium phosphate (Si-TCP; Skelite) and natural bone mineral derived scaffolds (Bio-oss)] were seeded with mesenchymal stem cells (MSC) and ectopically implanted for 8 and 16 weeks in immunodeficient mice. X-ray synchrotron radiation microtomography was used to derive 3D structural information on the same scaffolds both before and after implantation. Meaningful images and morphometric parameters such as scaffold and bone volume fraction, mean thickness and thickness distribution of the different phases as a function of the implantation time, were obtained. The used imaging algorithms allowed a direct comparison and registration of the 3D structure before and after implantation of the same sub-volume of a given scaffold. In this way it was possible to directly monitor the tissue engineered bone growth and the complete or partial degradation of the scaffold. Further, the detailed kinetics studies on Skelite scaffolds implanted for different length of times from 3 days to 24 weeks, revealed in the X-ray absorption histograms two separate peaks associated to HA and TCP. It was therefore possible to observe that the progressive degradation of the Skelite scaffolds was mainly due to the resorption of TCP. The different saturation times in the tissue engineered bone growth and in the TCP resorption confirmed that the bone growth was not limited the scaffold regions that were resorbed but continued in the inward direction with respect to the pore surface.

In vitro anti-trypanosomal activity of elatol isolated from red seaweed Laurencia dendroidea.

SUMMARY: Chagas' disease is a debilitating but comparatively neglected illness that affects about 15 million people. There is an urgent need to develop new, more effective, and less-toxic compounds. In this study, we assessed the in vitro anti-trypanosomal activity of the sesquiterpene elatol from the Brazilian red seaweed Laurencia dendroidea. We used electron microscopy to evaluate the effect of elatol on the morphology and ultrastructure of the parasite. Elatol showed a dose-dependent effect against the epimastigote, trypomastigote, and amastigote forms, with IC50 values of 45.4, 1.38, and 1.01 microm, respectively. Observation of treated intracellular amastigotes by light microscopy demonstrated a total elimination of the infection at a dose of 3.0 microm. In addition, the compound did not affect the red blood cells, and the CC50 value for LLCMK2 cells was 27.0 microm. Transmission and scanning electron micrographs showed aberrant-shaped cells and breaks in the plasma membrane, prominent swollen mitochondria, and extensive formation of cytoplasmic vacuoles in all the forms. This is the first report of the anti-trypanosomal effect of the sesquiterpene elatol.

A comparison between endoscopic and microscopic approaches for stapes surgery: a systematic review.

OBJECTIVES: To evaluate the surgical techniques, approaches, audiological outcomes and complications of endoscopic stapes surgery. METHODS: Systematic searches of the literature were performed in PubMed, Web of Science and Scopus databases, to identify studies of patients who underwent stapes surgery using endoscopic approaches and studies reporting objective post-operative hearing outcomes. The following information was extracted: surgery duration, complications, surgical technique and audiometric results. RESULTS: Fourteen studies were selected for appraisal, which included a total of 282 ears subjected to endoscopic stapes surgery. Endoscopic stapes surgery seems to provide adequate visualisation of the middle-ear structures, thereby allowing less invasive surgery and potentially equivalent audiological outcomes as compared with a traditional microscopic approach. Other advantages of endoscopic stapes surgery include decreased surgery time, a reduced need for drilling, and auditory results comparable to those of microscopic techniques. CONCLUSION: Studies have shown that endoscopic stapes surgery has similar surgical and functional advantages as compared with microscopic surgery.

Alterations in growth and branching of Neurospora crassa caused by sub-inhibitory concentrations of antifungal agents.

Six antifungal agents at subinhibitory concentrations were used for investigating their ability to affect the growth and branching in Neurospora crassa. Among the antifungals herein used, the azole agent ketoconazole at 0.5 microg/ml inhibited radial growth more than fluconazole at 5.0 microg/ml while amphotericin B at 0.05 microg/ml was more effective than nystatin at 0.05 microg/ml. Morphological alterations in hyphae were observed in the presence of griseofulvin, ketoconazole and terbinafine at the established concentrations. The antifungal agents were more effective on vegetative growth than on conidial germination. Terbinafine markedly reduced growth unit length (GU) by 54.89%, and caused mycelia to become hyperbranched. In all cases, there was a high correlation between hyphal length and number of tips (r > 0.9). All our results showed highly significant differences by ANOVA, (p < 0.001, alpha = 0.05). Considering that the hyphal tip is the main interface between the fungus and its environment/through which enzymes and toxins are secreted and nutrients absorbed, it would not be desirable to obtain a hyperbranched mycelia with inefficient doses of antifungal drugs.

Intra-cellular storage, transport and exocytosis of halogenated compounds in marine red alga Laurencia obtusa.

The production of secondary metabolites in seaweed have been related to a capability to partition compounds into cellular specialized storage structures, like gland cells and the corps en cerise (CC) or cherry bodies. The possible mechanisms that bring these compounds to the thallus surface remain poorly understood. Therefore, the aim of this work is perform a characterization of the CC and determine the intra-cellular dynamics of halogenated compounds in Laurencia obtusa. The dynamics of CC and the mechanisms related to the intra-cellular transport of halogenated compounds were evaluated by using optical tweezers and time-lapse video microscopy. The CC were isolated and its elemental composition was characterized using X-ray microanalysis. The cellular distribution of halogenated compounds was also demonstrated by fluorescence microscopy. Three-dimensional reconstruction technique was used to provide a visualization of the structures that connect CC to cell periphery. As main findings, we confirmed that the halogenated compounds are mainly found in CC and also in vesicles distributed along the cytoplasm and within the chloroplasts. We demonstrated that CC is mechanically fixed to cell periphery by a stalk-like connection. A vesicle transport though membranous tubular connections was seen occurring from CC to cell wall region. We also demonstrated a process of cortical cell death event, resulting in degradation of CC. We suggested that the vesicle transportation along membranous tubular connections and cell death events are related to the mechanisms of halogenated compounds exudation to the thallus surface and consequently with defensive role against herbivores and fouling.

Relationship between structural and biochemical characteristics and texture of corn grains.

The texture of corn grains is a fundamental characteristic for the industry as well as for grain producers and processors. To further understand the mechanisms involved in grain hardness, contrasting corn cultivars for grain hardness and protein quality were evaluated. The cultivars were Cateto L237/67 (hard endosperm and low protein value), QPM BR 451 (semi-hard endosperm and high protein value); Bolivia-2 (floury endosperm and low protein value), and Opaque-2 (floury endosperm and high protein value). Evaluations were carried out at 10, 20, 30, 40, 50, and 60 days after pollination in developing corn grains and in the mature grain. In developing grains, evaluation consisted in the determination of the area, percentage of starch granules, distribution of starch granules, and protein bodies in the endosperm. In mature corn grains, the parameters evaluated were: density, percentage of total proteins, levels of lysine and tryptophan, and banding pattern of zeins. The results indicate that the higher physical resistance of corn grains from the cultivars analyzed is influenced by the high percentage of total proteins, high synthesis of 27-kDa zeins, presence of protein bodies, and perfect organization of starch granules in the endosperm, independent of their sizes.

High resolution gamma-ray spectrometer with MHz capabilities for runaway electron studies at ASDEX Upgrade.

A new gamma-ray spectrometer with MHz capabilities has been developed to measure the bremsstrahlung emission spectrum in the gamma-ray energy band generated by MeV range runaway electrons in disruption experiments at ASDEX Upgrade. Properties of the runaway electrons are inferred from the measured bremsstrahlung spectrum by a deconvolution technique, particularly with regard to their maximum energy. Changes induced to the runaway electron velocity space are unambiguously observed both in massive gas injection and resonant magnetic perturbation experiments with the detector.

The upgraded JET gamma-ray cameras based on high resolution/high count rate compact spectrometers.

The JET gamma-ray cameras have been recently upgraded within the gamma-ray camera upgrade project in support of development of JET high performance deuterium plasma scenarios and in preparation of deuterium-tritium experiments. New, dedicated detectors based on a LaBr3 crystal and silicon photo-multipliers have been developed and replaced pre-existing CsI detectors in all 19 channels. The new instrument gives opportunity of making two-dimensional gamma-ray measurements with a counting rate capability exceeding 1 MCounts/s (MCps) and energy resolution better than 5% at 1.1 MeV. The upgrade is of relevance for fast ion and runaway electron physics studies in high performance deuterium discharges and also in plasmas with tritium at neutron yields in the range up to about 5 × 1017 n/s.

Design of gamma-ray spectrometers optimized for fast particle studies at ITER.

A set of gamma ray spectrometers has been designed for ITER within the Radial Gamma Ray Spectrometer (RGRS) project. The aim of this project is designing a system, integrated with the ITER radial neutron camera, which is able to measure the gamma-rays emitted from the plasma with a good energy resolution (about 1.5% at 4.44 MeV) and at high counting rates (in excess of 1 MHz). The RGRS will be able to operate both in the D phase and in the full-power DT phase and will measure gamma rays from (i) reactions between fast ions, such as α particles, and light impurities and (ii) bremsstrahlung emission generated by runaway electron interactions with both plasma bulk and tokamak walls. The RGRS detectors are arranged in nine lines of sights (able to cover a radial region with r < a/3), each featuring a large LaBr3 scintillator crystal. Due to the high neutron flux and magnetic field, several solutions have been adopted to guarantee a good signal to background ratio and MHz counting rate capabilities. The RGRS is capable to combine space and energy distribution measurements of α particles and runaway electrons, which will help the study of the fast particle physics in a burning plasma.

Project of cornea donation in the hospital complex of Santa Casa de Porto Alegre, Brazil.

Rio Grande do Sul is a state of 10 million inhabitants, with 800 patients on the transplantation waiting list (80 per million population [pmp]/y) with a mean waiting time of 2 years. Up to 2000, there were 11 to 15 cornea donors and 70 to 80 transplantations yearly. Seeking to increase the number of corneas available for transplantation and reduce the time on the waiting list, we initiated a project wherein the hospital transplantation coordinator trained the morgue staff to evaluate all deceased persons. If the person had no contraindication, the morgue staff called the coordinator to interview the family. Whenever donation was authorized, the coordinator communicated with the Cornea Bank to perform a removal. There was a major increase in the number of donations (220/y) with this project responsible for more than 70% of the cornea donors on cardiac arrest in the Rio Grande do Sul State. The mean time on the waiting list decreased to 14 months. This model was efficient, and must be implemented in other hospitals in the state, attempting to decrease both the list and the waiting time for a corneal transplant.

Detection of a chemical cue from the host seaweed Laurencia dendroidea by the associated mollusc Aplysia brasiliana.

Chemical cues from sessile hosts can attract mobile and associated organisms and they are also impotant to maintain associations and overall biodiversity, but the identity and molecular structures of these chemicals have been little explored in the marine environment. Secondary metabolites are recognized as possible chemical mediators in the association between species of Laurencia and Aplysia, but the identity of the compounds has not been established. Here, for the first time, we experimentally verify that the sesquiterpene (+)-elatol, a compound produced by the red seaweed Laurencia dendroidea, is a chemical cue attracting the associated sea hare Aplysia brasiliana. In addition to revealing the nature of the chemical mediation between these two species, we provide evidence of a chemical cue that allows young individuals of A. brasiliana to live in association with L. dendroidea. This study highlights the importance of chemical cues in Laurencia-Aplysia association.

In vitro chondrogenic commitment of human Wharton's jelly stem cells by co-culture with human articular chondrocytes.

Wharton's jelly stem cells (WJSCs) are a potential source of transplantable stem cells in cartilage-regenerative strategies, due to their highly proliferative and multilineage differentiation capacity. We hypothesized that a non-direct co-culture system with human articular chondrocytes (hACs) could enhance the potential chondrogenic phenotype of hWJSCs during the expansion phase compared to those expanded in monoculture conditions. Primary hWJSCs were cultured in the bottom of a multiwell plate separated by a porous transwell membrane insert seeded with hACs. No statistically significant differences in hWJSCs duplication number were observed under either of the culture conditions during the expansion phase. hWJSCs under co-culture conditions show upregulations of collagen type I and II, COMP, TGFß1 and aggrecan, as well as of the main cartilage transcription factor, SOX9, when compared to those cultured in the absence of chondrocytes. Chondrogenic differentiation of hWJSCs, previously expanded in co-culture and monoculture conditions, was evaluated for each cellular passage using the micromass culture model. Cells expanded in co-culture showed higher accumulation of glycosaminoglycans (GAGs) compared to cells in monoculture, and immunohistochemistry for localization of collagen type I revealed a strong detection signal when hWJSCs were expanded under monoculture conditions. In contrast, type II collagen was detected when cells were expanded under co-culture conditions, where numerous round-shaped cell clusters were observed. Using a micromass differentiation model, hWJSCs, previously exposed to soluble factors secreted by hACs, were able to express higher levels of chondrogenic genes with deposition of cartilage extracellular matrix components, suggesting their use as an alternative cell source for treating degenerated cartilage. Copyright © 2015 John Wiley & Sons, Ltd.

A Feasibility Study of High-Strength Bi-2223 Conductor for High-Field Solenoids.

We performed a feasibility study on a high-strength Bi2-x Pb x Sr2Ca2Cu3O10-x (Bi-2223) tape conductor for high-field solenoid applications. The investigated conductor, DI-BSCCO Type HT-XX, is a pre-production version of Type HT-NX, which has recently become available from Sumitomo Electric Industries (SEI). It is based on their DI-BSCCO Type H tape, but laminated with a high-strength Ni-alloy. We used stress-strain characterizations, single- and double-bend tests, easy- and hard-way bent coil-turns at various radii, straight and helical samples in up to 31.2 T background field, and small 20-turn coils in up to 17 T background field to systematically determine the electro-mechanical limits in magnet-relevant conditions. In longitudinal tensile tests at 77 K, we found critical stress- and strain-levels of 516 MPa and 0.57%, respectively. In three decidedly different experiments we detected an amplification of the allowable strain with a combination of pure bending and Lorentz loading to ≥ 0.92% (calculated elastically at the outer tape edge). This significant strain level, and the fact that it is multi-filamentary conductor and available in the reacted and insulated state, makes DI-BSCCO HT-NX highly suitable for very high-field solenoids, for which high current densities and therefore high loads are required to retain manageable magnet dimensions.

Improvement of adynamic bone disease after renal transplantation.

Low bone remodeling and relatively low serum parathyroid hormone (PTH) levels characterize adynamic bone disease (ABD). The impact of renal transplantation (RT) on the course of ABD is unknown. We studied prospectively 13 patients with biopsy-proven ABD after RT. Bone histomorphometry and bone mineral density (BMD) measurements were performed in the 1st and 12th months after RT. Serum PTH, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and osteocalcin were measured regularly throughout the study. Serum PTH levels were slightly elevated at transplantation, normalized at the end of the third month and remained stable thereafter. Bone biopsies performed in the first month after RT revealed low bone turnover in all patients, with positive bone aluminum staining in 5. In the 12th month, second biopsies were performed on 12 patients. Bone histomorphometric dynamic parameters improved in 9 and were completely normalized in 6, whereas no bone mineralization was detected in 3 of these 12 patients. At 12 months post-RT, no bone aluminum was detected in any patient. We also found a decrease in lumbar BMD and an increase in femoral BMD. Patients suffering from ABD, even those with a reduction in PTH levels, may present partial or complete recovery of bone turnover after successful renal transplantation. However, it is not possible to positively identify the mechanisms responsible for the improvement. Identifying these mechanisms should lead to a better understanding of the physiopathology of ABD and to the development of more effective treatments.

Performance of the prototype LaBr3 spectrometer developed for the JET gamma-ray camera upgrade.

In this work, we describe the solution developed by the gamma ray camera upgrade enhancement project to improve the spectroscopic properties of the existing JET γ-ray camera. Aim of the project is to enable gamma-ray spectroscopy in JET deuterium-tritium plasmas. A dedicated pilot spectrometer based on a LaBr3 crystal coupled to a silicon photo-multiplier has been developed. A proper pole zero cancellation network able to shorten the output signal to a length of 120 ns has been implemented allowing for spectroscopy at MHz count rates. The system has been characterized in the laboratory and shows an energy resolution of 5.5% at Eγ = 0.662 MeV, which extrapolates favorably in the energy range of interest for gamma-ray emission from fast ions in fusion plasmas.