Ultra-Low Power Sensor Devices for Monitoring Physical Activity and Respiratory Frequency in Farmed Fish.

Integration of technological solutions aims to improve accuracy, precision and repeatability in farming operations, and biosensor devices are increasingly used for understanding basic biology during livestock production. The aim of this study was to design and validate a miniaturized tri-axial accelerometer for non-invasive monitoring of farmed fish with re-programmable schedule protocols. The current device (AE-FishBIT v.1s) is a small (14 mm × 7 mm × 7 mm), stand-alone system with a total mass of 600 mg, which allows monitoring animals from 30 to 35 g onwards. The device was attached to the operculum of gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax) juveniles for monitoring their physical activity by measurements of movement accelerations in x- and y-axes, while records of operculum beats (z-axis) served as a measurement of respiratory frequency. Data post-processing of exercised fish in swimming test chambers revealed an exponential increase of fish accelerations with the increase of fish speed from 1 body-length to 4 body-lengths per second, while a close relationship between oxygen consumption (MO2) and opercular frequency was consistently found. Preliminary tests in free-swimming fish kept in rearing tanks also showed that device data recording was able to detect changes in daily fish activity. The usefulness of low computational load for data pre-processing with on-board algorithms was verified from low to submaximal exercise, increasing this procedure the autonomy of the system up to 6 h of data recording with different programmable schedules. Visual observations regarding tissue damage, feeding behavior and circulating levels of stress markers (cortisol, glucose, and lactate) did not reveal at short term a negative impact of device tagging. Reduced plasma levels of triglycerides revealed a transient inhibition of feed intake in small fish (sea bream 50-90 g, sea bass 100-200 g), but this disturbance was not detected in larger fish. All this considered together is the proof of concept that miniaturized devices are suitable for non-invasive and reliable metabolic phenotyping of farmed fish to improve their overall performance and welfare. Further work is underway for improving the attachment procedure and the full device packaging.

An Intraoperative Visualization System Using Hyperspectral Imaging to Aid in Brain Tumor Delineation.

Hyperspectral imaging (HSI) allows for the acquisition of large numbers of spectral bands throughout the electromagnetic spectrum (within and beyond the visual range) with respect to the surface of scenes captured by sensors. Using this information and a set of complex classification algorithms, it is possible to determine which material or substance is located in each pixel. The work presented in this paper aims to exploit the characteristics of HSI to develop a demonstrator capable of delineating tumor tissue from brain tissue during neurosurgical operations. Improved delineation of tumor boundaries is expected to improve the results of surgery. The developed demonstrator is composed of two hyperspectral cameras covering a spectral range of 400-1700 nm. Furthermore, a hardware accelerator connected to a control unit is used to speed up the hyperspectral brain cancer detection algorithm to achieve processing during the time of surgery. A labeled dataset comprised of more than 300,000 spectral signatures is used as the training dataset for the supervised stage of the classification algorithm. In this preliminary study, thematic maps obtained from a validation database of seven hyperspectral images of in vivo brain tissue captured and processed during neurosurgical operations demonstrate that the system is able to discriminate between normal and tumor tissue in the brain. The results can be provided during the surgical procedure (~1 min), making it a practical system for neurosurgeons to use in the near future to improve excision and potentially improve patient outcomes.

Influence of HLA Matching on the Efficacy of Allogeneic Mesenchymal Stromal Cell Therapies for Osteoarthritis and Degenerative Disc Disease.

BACKGROUND: The necessity for more effective therapies for chronic osteoarticular diseases has led to the development of treatments based on mesenchymal stem cells (MSCs), the natural precursors of musculoskeletal tissue. Treatments with autologous MSCs yielded excellent results, with nearly 70% improvement of pain and disability in osteoarthritis and degenerative disc disease. Using allogeneic MSCs is logistically more convenient and would widen the pool of eligible patients, but potential immune rejection should be considered. In this context, MSCs are purportedly immune evasive and better tolerated than other cell types. METHODS: We used samples collected during the performance of 2 randomized clinical trials using allogeneic bone marrow MSCs for treatment of osteoarthritis (NCT01586312) and degenerative disc disease (NCT01860417). Serum samples were used to determine anti-HLA antibodies, whereas either blood or MSC samples were used for HLA typing of recipients and donors, respectively. Algofunctional indexes were used as indicators of clinical evolution, and the correlation between the number of donor-host HLA mismatches and the efficacy of treatment was determined. RESULTS: Immune response was weak and transient, with reactivity decaying during the first year. Consistently, better donor-recipient HLA matching did not enhance efficacy. CONCLUSIONS: This lack of reactivity is presumably due to the cooperation of 2 factors, (1) downregulation of the host immune responses by the transplanted MSCs and (2) effective insulation of these cells inside the articular cavity or the intervertebral disc, respectively. Interestingly, better HLA matching did not enhance efficacy. These observations have medical relevance as they support the clinical use of allogeneic cells, at least as a single-dose administration. Multiple-dose applications will require further research to exclude possible sensitization.

Treatment of Knee Osteoarthritis With Allogeneic Bone Marrow Mesenchymal Stem Cells: A Randomized Controlled Trial.

BACKGROUND: Osteoarthritis is the most prevalent joint disease and a common cause of joint pain, functional loss, and disability. Conventional treatments demonstrate only modest clinical benefits without lesion reversal. Autologous mesenchymal stromal cell (MSC) treatments have shown feasibility, safety, and strong indications for clinical efficacy. We performed a randomized, active control trial to assess the feasibility and safety of treating osteoarthritis with allogeneic MSCs, and we obtain information regarding the efficacy of this treatment. METHODS: We randomized 30 patients with chronic knee pain unresponsive to conservative treatments and showing radiological evidence of osteoarthritis into 2 groups of 15 patients. The test group was treated with allogeneic bone marrow MSCs by intra-articular injection of 40 × 10(6) cells. The control group received intra-articular hyaluronic acid (60 mg, single dose). Clinical outcomes were followed for 1 year and included evaluations of pain, disability, and quality of life. Articular cartilage quality was assessed by quantitative magnetic resonance imaging T2 mapping. RESULTS: Feasibility and safety were confirmed and indications of clinical efficacy were identified. The MSC-treated patients displayed significant improvement in algofunctional indices versus the active controls treated with hyaluronic acid. Quantification of cartilage quality by T2 relaxation measurements showed a significant decrease in poor cartilage areas, with cartilage quality improvements in MSC-treated patients. CONCLUSIONS: Allogeneic MSC therapy may be a valid alternative for the treatment of chronic knee osteoarthritis that is more logistically convenient than autologous MSC treatment. The intervention is simple, does not require surgery, provides pain relief, and significantly improves cartilage quality.

Consequences of cavity size and chemical environment on the adsorption properties of isoreticular metal-organic frameworks: an inverse gas chromatography study.

The role of the structure of three isoreticular metal-organic frameworks (IRMOFs) on their adsorption behavior has been studied in this work, selecting different kinds of volatile organic compounds (VOCs) as adsorbates (alkanes, alkenes, cycloalkanes, aromatics and chlorinated). For this purpose, three samples (IRMOF-1, IRMOF-8 and IRMOF-10) with cubic structure and without functionalities on the organic linkers were synthesized. Adsorption capacities at infinite dilution were derived from the adsorption isotherms, whereas thermodynamic properties have been determined from chromatographic retention volume. The capacity and the strength of adsorption were strongly influenced by the adsorbate size. This effect is especially relevant for n-alkanes adsorption, indicating the key role of the cavity size on this phenomenon, and hence the importance of the IRMOF structural properties. A different behavior has been observed for the polar compounds, where an enhancement on the specificity of the adsorption with the π-electron rich regions was observed. This fact suggests the specific interaction of these molecules with the organic linkers of the IRMOFs.

Effect of carbon nanofiber functionalization on the adsorption properties of volatile organic compounds.

The effect of the chemical activation, using HNO3, of a commercial carbon nanofiber (CNF) on its surface chemistry and adsorption properties is studied in this work. The adsorption of different alkanes (linear and cyclic), aromatic compounds and chlorohydrocarbons on both the parent and the oxidized CNF were compared. Temperature-programmed desorption results, in agreement with X-ray photoelectron spectroscopy experiments, reveal the existence of oxygen groups on the surface of the treated CNF. Capacity of adsorption was derived from the adsorption isotherms, whereas thermodynamic properties (enthalpy of adsorption, surface free energy characteristics) have been determined from chromatographic retention data. Both the capacity and the strength of adsorption decrease after the oxidant treatment of the carbon nanofibers, although in the case of chlorinated compounds the specific component of the surface energy shows an important increase. For n-alkanes and cyclic compounds, it was demonstrated that the presence of oxygen surface groups does not affect their interaction, the morphology of the surface being the key parameter. The oxidation of the nanofiber leads to steric limitations of the adsorption. In the adsorption of aromatic compounds, these limitations are compensated by the nucleophilic interactions between the aromatic ring and surface oxygenated groups, leading to similar performances of both materials. The absence of nucleophilic groups in the chlorinated compounds hinders their adsorption on the activated nanofibers.

Sulphur poisoning of palladium catalysts used for methane combustion: effect of the support.

Four different supported palladium catalysts (using alumina, silica, zirconia and titania as supports), prepared by incipient wetness impregnation, were tested as catalysts for methane oxidation in presence of sulphur dioxide. The catalyst supported on zirconia showed the best performance, whereas the silica-supported one showed the fastest deactivation. Temperature-programmed desorption experiments of the poisoned catalysts suggest that SO(2) adsorption capacity of the support plays a key role in the catalyst poisoning. In order to study the effect of promoters, expected to improve the thermal stability and thioresistance of the catalyst, commercial zirconia modified by yttrium and lantane was tested as supports. It was found that the presence of these promoters does not improve the performance of the zirconia-supported catalyst. A deactivation model -- considering two different active sites (fresh and poisoning), pseudo-first order dependence on methane concentration and poisoning rate depending on sulphur concentration and fraction of non-poisoned palladium -- was used for modelling the deactivation behaviour.

Enhancement of the CO(2) retention capacity of X zeolites by Na- and Cs-treatments.

Adsorption of carbon dioxide on alkaline modified X zeolites was investigated by temperature programmed desorption (TPD) analysis of these materials previously saturated with CO(2) at 50, 100 and 200 degrees C. Parent X zeolite (in its sodium form) was treated with different sodium and cesium aqueous solutions, using both carbonates and hydroxides as precursors. The resulting materials were characterised by nitrogen physisorption, XRD, and NH(3)-TPD, in order to determine their morphological, crystallographic and chemical properties. Slight desilication phenomena were observed using hydroxides as precursors, whereas the treatment with Cs salts lead to higher crystallinity losses. Several successive adsorption-desorption cycles were carried out in order to check the regenerability of the adsorbents. Cesium-treated zeolites present higher carbon dioxide retention capacities than the sodium treated and than the parent material. When working with these Cs-modified materials, the desorption takes place mainly at temperatures between 250 and 400 degrees C, results of great practical interest, since it allows the use these kinds of materials for adsorption-desorption cycles. The evolution of the retention capacity with temperature is also markedly more positive for Cs-treated zeolite, especially when carbonate is used as the precursor. These materials maintain high retention capacities at 100 degrees C (10mg g(-1)) and even at 200 degrees C (3mg g(-1)), temperatures at which the most of the adsorbents are inactive.

Oxidation of trichloroethene over metal oxide catalysts: kinetic studies and correlation with adsorption properties.

The performance of bulk chromium oxide is compared with that of a Mn commercial catalyst for the deep oxidation of trichloroethene (1000-2500ppmv, 55h(-1) space velocity) in air, in dry and wet (20000ppm of H(2)O) conditions, in terms of activity, selectivity and stability. Chromium oxide was found to be more active (on a catalyst weight basis), however its activity decreases continuously with time on stream. The presence of water increases its stability, the Mn catalyst showing the opposite behaviour. The effect of water on the Cr catalyst can be explained according to the Deacon equilibrium, as the presence of water tends to decrease the Cl(2) concentration, assumed to be responsible of the catalyst deactivation. Regarding to the selectivity, the Mn catalyst yields C(2)Cl(4), CCl(4) and CHCl(3) as organochlorinated by-products, whereas chromium oxide produces only trace amounts of CCl(4). Simple power-law kinetics expressions (first-order for Mn and zero-order for Cr) provide fairly good fits for the evolution of the conversion with the temperature. Furthermore, the kinetic behaviour of chromium oxide can be represented with a Langmuir-Hinshelwood model taking into account the chlorine inhibitory effect.

Adsorption of volatile organic compounds onto carbon nanotubes, carbon nanofibers, and high-surface-area graphites.

The adsorption of different alkanes (linear and cyclic), aromatics, and chlorohydrocarbons onto different nonmicroporous carbons--multiwalled carbon nanotubes (CNTs), carbon nanofibers (CNFs), and high-surface-area graphites (HSAGs)--is studied in this work by inverse gas chromatography (IGC). Capacity of adsorption was derived from the isotherms of adsorption, whereas thermodynamic properties (enthalpy of adsorption, surface free energy characteristics) have been determined from chromatographic retention data. HSAGs present the highest adsorption capacity, followed by CNTs and CNFs (although CNTs present an intermediate surface area between the two HSAG studied). Among the different adsorbates tested, benzene exhibits the highest adsorption capacity, and the same trend is observed in the enthalpy of adsorption. From surface free energy data, enthalpies of adsorption of polar compounds were divided into dispersive and specific contributions. The interactions of cyclic (benzene and cyclohexane) and chlorinated compounds (trichloroethylene, tetrachloroethylene, and chloroform) with the surfaces are mainly dispersive over all the carbons tested, CNTs being the material with the highest dispersive contribution, as was deduced also from the entropy parameter. Adsorption parameters were correlated with morphological and chemical properties of the materials.

Oxidation of methane over palladium catalysts: effect of the support.

This work is focused on the deep catalytic oxidation of methane over supported palladium catalysts. The influences of the metal loading, oxidation state of palladium, nature of supports, presence of promoters in the supports (for zirconia-based supports), and thermal stability have been studied experimentally. Catalysts were prepared by incipient wetness of commercially available supports with aqueous solutions of palladium nitrate. For gamma-alumina support, it was observed that the optimal amount of palladium is between 0.5% and 2%, with higher amounts leading to a loss in specific activity. Concerning the oxidation state of the catalyst, it is concluded that for all the supports tested in the present work, a reduction of the catalyst is not needed, yielding the same conversion at steady state catalysts reduced and oxidised. The thermal stability of various supported catalysts were also studied, zirconia supports being the most active. These supports, specially Y-modified zirconia support, do not suffer appreciable deactivation below 500 degrees C.

Adsorption characterisation of different volatile organic compounds over alumina, zeolites and activated carbon using inverse gas chromatography.

Adsorption parameters (enthalpy of adsorption, free energy of adsorption) of several alkanes, cyclic hydrocarbons, aromatic hydrocarbons and chlorinated compounds on different adsorbents (alumina, zeolites 13X and 5 A, and activated carbon) were determined by inverse gas chromatography. Dispersive surface energy interaction and specific interaction parameters were determined for each solute-adsorbent system. It was found that mesoporous alumina presents lower enthalpy of adsorption than the microporous materials. Furthermore, zeolite 13X, which has wider pores than zeolite 5 A, exhibits a higher adsorption capacity.

Characterization of Co, Fe and Mn-exchanged zeolites by inverse gas chromatography.

The adsorption of several alkanes, cyclic hydrocarbons, aromatic hydrocarbons and chlorinated compounds on NaX, CaA, and exchanged Co, Mn and Fe zeolites as adsorbents was investigated. Zeolite composition and structure was determined by ICP-mass spectroscopy, XRD, and nitrogen adsorption. Adsorption parameters (enthalpy of adsorption and free energy of adsorption) as well as dispersive surface energy interaction and specific interaction parameters were determined for each solute-adsorbent system by inverse gas chromatography (IGC). The original zeolites NaX and CaA show the higher values of enthalpy of adsorption but specific interactions depend on the metal exchanged. Zeolites Mn-NaX and Co-NaX exhibit the strongest interactions with benzene, whereas zeolite Co-CaA shows the strongest interactions with chlorinated compounds. The trivalent cation (Fe3+) does not affect the either the adsorption efficiency or specific interaction.

Catalytic combustion of methane over commercial catalysts in presence of ammonia and hydrogen sulphide.

The performance of different commercially available catalysts (supported Pd, Pt, Rh, bimetallic Pd-Pt, and Cr-Cu-Ti oxide catalyst) for the oxidation of methane, alone and in presence of ammonia and hydrogen sulphide is studied in this work. Catalysts performance was evaluated both in terms of activity and resistance to poisoning. The main conclusions are that supported Pd and Rh, present the highest activities for methane oxidation, both alone and in presence of ammonia, whereas they are severely poisoned in presence of H2S. Pt and Cr-Cu-Ti are less active but more sulphur resistant, but their activity is lower than the residual activity of sulphur-deactivated Pd and Rh catalysts. The Pd-Pt catalyst exhibits low activity and it is quickly deactivated in presence of hydrogen sulphide.