Exploring Reversible Redox Behavior in the 6H-BaFeO3-δ (0 < δ < 0.4) System: Impact of Fe3+/Fe4+ Ratio on CO Oxidation.

This work is devoted to evaluating the relationship between the oxygen content and catalytic activity in the CO oxidation process of the 6H-type BaFeO3-δ system. Strong evidence is provided about the improvement of catalytic performance with increasing Fe average oxidation state, thus suggesting the involvement of lattice oxygen in the catalytic process. The compositional and structural changes taking place in both the anionic and cationic sublattices of the catalysts during redox cycles have been determined by temperature-resolved neutron diffraction. The obtained results evidence a structural transition from hexagonal (P63/mmc) to orthorhombic (Cmcm) symmetry. This transition is linked to octahedra distortion when the Fe3+ concentration exceeds 40% (δ values higher than 0.2). The topotactical character of the redox process is maintained in the δ range 0 < δ < 0.4. This suggests that the cationic framework is only subjected to slight structural modifications during the oxygen exchange process occurring during the catalytic cycle.

Ultrasound-promoted synthesis of a copper-iron-based catalyst for the microwave-assisted acyloxylation of 1,4-dioxane and cyclohexene.

A copper-iron-based catalyst has been prepared by a low-temperature co-precipitation and sonication method. The use of high-energy ultrasound reduces the time required for the preparation process from one workweek to one day with respect to the catalysts obtained by conventional coprecipitation and thermal treatment methods. The resulting material has been characterized at compositional, textural, structural, and chemical levels by ICP-AES, BET, SEM-EDS, XRD, TEM, and FTIR among other techniques. The material shows catalytic activity in the acyloxylation reaction of 1,4-dioxane and cyclohexene under microwave irradiation. In parallel with the optimized catalyst synthesis, the use of microwaves allowed for a substantial improvement in the outcome of the reaction in terms of cleanliness, yield, and time.

A Novel Route for the Easy Production of Thermochromic VO2 Nanoparticles.

In this work, a simple, fast and dry method for the fabrication of a thermochromic product with a high load of VO2 (M1) consisting of the controlled heat treatment of pure vanadium nanoparticles in air is presented. After a complete design of experiments, it is concluded that the most direct way to attain the maximum transformation of V into VO2 (M1) consists of one cycle with a fast heating ramp of 42 °C s-1 , followed by keeping 700 °C for 530-600 seconds, and a subsequent cooling at 0.05 °C s-1 . Careful examination of these results lead to a second optimum, even more suitable for industrial production (quicker and less energy-intensive because of its lower temperatures and shorter times), consisting of subjecting V to two consecutive cycles of temperatures and times (625 °C for 5 minutes) with similar preheating (42 °C s-1 ) but a much faster postcooling (∼ 8 °C s-1 ). These green reactions only use the power for heating a tube open to atmosphere and a vanadium precursor; without assistance of reactive gases or catalysts, and no special vacuum or pressure requirements. The best products present similar thermochromic properties but higher thermal stability than commercial VO2 particles. These methods can be combined with VO2 doping.

Size matters: Zebrafish (Danio rerio) as a model to study toxicity of nanoplastics from cells to the whole organism.

The contamination of the aquatic environment by plastic nanoparticles is becoming a major concern due to their potential adverse effects in aquatic biota. Therefore, in-depth knowledge of their uptake, trafficking and effects at cellular and systemic levels is essential to understand their potential impacts for aquatic species. In this work, zebrafish (Danio rerio) was used as a model and our aims were: i) to determine the distribution, uptake, trafficking, degradation and genotoxicity of polystyrene (PS) NPs of different sizes in a zebrafish cell line; ii) to study PS NPs accumulation, migration of immune cells and genotoxicity in larvae exposed to PS NPs; and iii) to assess how PS NPs condition the survival of zebrafish larvae exposed to a pathogen and/or how they impact the resistance of an immunodeficient zebrafish. Our results revealed that the cellular distribution differed depending on the particle size: the 50 nm PS NPs were more homogeneously distributed in the cytoplasm and the 1 µM PS NPs more agglomerated. The main endocytic mechanisms for the uptake of NPs were dynamin-dependent internalization for the 50 nm NPs and phagocytosis for the 1 µm nanoparticles. In both cases, degradation in lysosomes was the main fate of the PS NPs, which generated alkalinisation and modified cathepsin genes expression. These effects at cellular level agree with the results in vivo, since lysosomal alkalization increases oxidative stress and vice versa. Nanoparticles mainly accumulated in the gut, where they triggered reactive oxygen species, decreased expression of the antioxidant gene catalase and induced migration of immune cells. Finally, although PS NPs did not induce mortality in wild-type larvae, immunodeficient and infected larvae had decreased survival upon exposure to PS NPs. This fact could be explained by the mechanical disruption and/or the oxidative damage caused by these NPs that increase their susceptibility to pathogens.

Nanoplastics: From tissue accumulation to cell translocation into Mytilus galloprovincialis hemocytes. resilience of immune cells exposed to nanoplastics and nanoplastics plus Vibrio splendidus combination.

Plastic litter is an issue of global concern. In this work Mytilus galloprovincialis was used to study the distribution and effects of polystyrene nanoplastics (PS NPs) of different sizes (50 nm, 100 nm and 1 µm) on immune cells. Internalization and translocation of NPs to hemolymph were carried out by in vivo experiments, while endocytic routes and effects of PS NPs on hemocytes were studied in vitro. The smallest PS NPs tested were detected in the digestive gland and muscle. A fast and size-dependent translocation of PS NPs to the hemolymph was recorded after 3 h of exposure. The internalization rate of 50 nm PS NPs was lower when caveolae and clathrin endocytosis pathways were inhibited. On the other hand, the internalization of larger particles decreased when phagocytosis was inhibited. The hemocytes exposed to NPs had changes in motility, apoptosis, ROS and phagocytic capacity. However, they showed resilience when were infected with bacteria after PS NP exposure being able to recover their phagocytic capacity although the expression of the antimicrobial peptide Myticin C was reduced. Our findings show for the first time the translocation of PS NPs into hemocytes and how their effects trigger the loss of its functional parameters.

The role of miRNAs in male human reproduction: a systematic review.

BACKGROUND: The presence of miRNAs in human reproductive tissue is intriguing and suggests the possibility that these important regulatory molecules play a role in reproductive function. However, the regulatory role of miRNAs in reproductive tissue remains poorly understood with a significant amount of controversial and contradicting data. OBJECTIVES: To systematically review the high-quality studies published to date investigating miRNAs associated with male human reproduction in order to describe their roles and relations with infertility and update the knowledge in the field. MATERIALS AND METHODS: A comprehensive systematic review of the published literature in MEDLINE-PubMed and EMBASE databases from the earliest available online indexing year until June 2018 (complimentary search until July 2019) was performed, in accordance with the PRISMA guidelines. We have included descriptive, case-control, cross-sectional, and observational prospective and retrospective studies in which fertile/infertile men were well-defined. The primary outcome was the miRNA expression in testis, epididymis, sperm cells, seminal plasma, and extracellular vesicles (i.e., exosomes and microvesicles). RESULTS: We identified 25,204 articles, of which 42 were selected for qualitative analysis. Of the 42 articles included, 15 evaluated the miRNAs in testis, five in epididymis, 13 in spermatozoa, and 11 in seminal plasma and/or extracellular vesicles. Two studies tackled more than one sub-group. As far as miRNA presence and content, the results of this systematic review indicated that every tissue/cell contains a well-defined and stable population of miRNAs that could be potentially related to spermatogenesis and embryogenesis. DISCUSSION AND CONCLUSION: Our systematic review of descriptive and observational studies shows a consistent relationship between aberrant miRNA expression and infertility. Therefore, it seems reasonable that measuring the expression of particular miRNAs might be useful not only as infertility biomarkers, but also for developing therapeutic strategies.

Multicenter randomized controlled trial comparing the effectiveness and safety of hydrocellular and hydrocolloid dressings for treatment of category II pressure ulcers in patients at primary and long-term care institutions.

BACKGROUND: Pressure ulcers are a major burden to patients because they affect health, well-being, and health-related quality of life. Thus, prevention and early treatment of pressure ulcers is a major challenge for health care professionals. OBJECTIVE: To compare the efficacy of hydrocellular and hydrocolloid dressings after 8 weeks of treatment of category II pressure ulcers. DESIGN: A prospective multicenter clinical trial with blinded outcome assessors. PARTICIPANTS AND SETTINGS: Adult patients with category II pressure ulcers from primary and long-term care institutions on Majorca island. METHODS: Category II ulcers were treated with ALLEVYN Adhesive® dressings or VARIHESIVE® GEL CONTROL dressings, with the primary outcome being healing of the ulcers in 8 weeks. Blinded confirmation of ulcer healing was performed by a treatment-group assessment committee. Estimates of cumulative survival probabilities were determined using the Kaplan-Meier method and analyses of effectiveness were performed using the chi-squared test. RESULTS: A total of 169 patients with pressure ulcers were enrolled, 84 of whom received hydrocellular dressings and 85 of whom received hydrocolloid dressings. A total of 58% were women and 56% were from primary care institutions. The hydrocellular dressing group had a higher percentage of healed pressure ulcers at 8 weeks (90.7% vs. 77.1%, p = 0.039) and a shorter average healing time (3 weeks vs. 4 weeks, p = 0.015). Analysis of safety outcomes at 8 weeks indicated that the hydrocellular dressing group had a smaller proportion of ulcers that were unhealed (3.9% vs. 7.1%) and a smaller proportion of ulcers that progressed to a higher category or infection (5.3% vs. 15.7%), although these differences were not statistically significant. CONCLUSIONS: This study of patients with category II pressure ulcers indicated that hydrocellular dressings were superior to hydrocolloid dressings in terms of healing at 8 weeks and time required for healing, although these two dressings had similar safety profiles.

The achievement of boar sperm in vitro capacitation is related to an increase of disrupted disulphide bonds and intracellular reactive oxygen species levels.

The aim of this work was to determine the relationship of intracellular reactive oxygen species (ROS) and the disulphide bonds established between sperm proteins with the achievement of capacitation in boar spermatozoa. With this purpose, spermatozoa were incubated in a specifically designed in vitro capacitation medium (CM) in the presence or absence of reduced glutathione (GSH). Incubation of boar spermatozoa in CM for 4 h significantly (p < 0.05) increased free cysteine residues, which is a marker of disrupted disulphide bonds, and also intracellular ROS levels. The addition of GSH to the medium prevented most capacitation-like changes in sperm motility, membrane lipid disorder, mitochondrial membrane potential, intracellular calcium levels and localization of tyrosine-phosphorylated proteins (pTyr), but not in tyrosine phosphorylation of P32. These effects were accompanied by the inhibition of the ability of sperm cells to trigger the acrosome exocytosis in response to progesterone. When GSH was added together with progesterone after 4 h of incubation, acrosome exocytosis was not altered, but the subsequent decrease in intracellular calcium observed in controls cells was inhibited. Furthermore, co-incubation of oocytes with spermatozoa previously incubated in CM in the presence of GSH for 4 h significantly (p < 0.05) increased the number of spermatozoa attached to the oocyte surface but decreased normal fertilization rates. Our results suggest that boar sperm capacitation is related to an increase in disrupted disulphide bonds and intracellular ROS levels and that both events are related to the regulation of hyperactivated motility, intracellular calcium dynamics, sperm binding ability to the oocyte and achievement of proper nuclear decondensation upon oocyte penetration.

Cytotoxicity of CeO2 nanoparticles using in vitro assay with Mytilus galloprovincialis hemocytes: Relevance of zeta potential, shape and biocorona formation.

Over the last decades, the growth in nanotechnology has provoked an increase in the number of its applications and consumer products that incorporate nanomaterials in their formulation. Metal nanoparticles are released to the marine environment and they can interact with cells by colloids forces establish a nano-bio interface. This interface can be compatible or generate bioadverse effects to cells. The daily use of CeO2 nanoparticles (CeO2 NPs) in industrial catalysis, sunscreen, fuel cells, fuel additives and biomedicine and their potential release into aquatic environments has turned them into a new emerging pollutant of concern. It is necessary to assess of effects of CeO2 NPs in aquatic organisms and understand the potential mechanisms of action of CeO2 NP toxicity to improve our knowledge about the intrinsic and extrinsic characteristic of CeO2 NPs and the interaction of CeO2 NPs with biomolecules in different environment and biological fluids. The conserved innate immune system of bivalves represents a useful tool for studying immunoregulatory responses when cells are exposed to NPs. In this context, the effects of two different CeO2 NPs with different physico-chemical characteristics (size, shape, zeta potential and Ce+3/Ce+4 ratio) and different behavior with biomolecules in plasma fluid were studied in a series of in vitro assays using primary hemocytes from Mytilus galloprovincialis. Different cellular responses such as lysosome membrane stability, phagocytosis capacity and extracellular reactive oxygen species (ROS) production were evaluated. Our results indicate that the agglomeration state of CeO2 NPs in the exposure media did not appear to have a substantial role in particle effects, while differences in shape, zeta potential and biocorona formation in NPs appear to be important in provoking negative impacts on hemocytes. The negative charge and the rounded shape of CeO2 NPs, which formed Cu, Zn-SOD biocorona in hemolymph serum (HS), triggered higher changes in the biomarker of stress (LMS) and immunological parameters (ROS and phagocytosis capacity). On the other hand, the almost neutral surface charge and well-faceted shape of CeO2 NPs did not show either biocorona formation in HS under tested conditions or significant responses. According to the results, the most relevant conclusion of this work is that not only the physicochemical characterization of CeO2 NPs plays an important role in NPs toxicity but also the study of the interaction of NPs with biological fluids is essential to know it behavior and toxicity at cellular level.

Effects of the antimicrobial peptide protegrine 1 on sperm viability and bacterial load of boar seminal doses.

The presence of bacteria adversely affects boar sperm quality of seminal doses intended for artificial insemination. Currently, the most common measure to prevent bacteriospermia is the addition of antibiotics in semen extenders; however, mounting evidence shows that microbial resistance exists. A promising alternative to replace antibiotics are antimicrobial peptides. In this study, the effects of the antimicrobial peptide protegrine 1 (PG1) on the sperm viability and bacterial load of boar seminal doses were evaluated. Three different concentrations of PG1 (2.5, 25 and 100 µg/ml) were tested over a storing period of 10 days at 17°C. Sperm viability was analysed by fluorescence microscopy (SYBR14/propidium iodide), and bacterial load was assessed by plating 100 µl of each sample in Luria-Bertani medium and incubated at 37°C for 72 hr under aerobic conditions. Protegrine 1 was effective in controlling the bacterial load in all the assessed concentrations (p < .05), reaching the lowest values at the highest concentrations of the antimicrobial peptide. Nevertheless, sperm viability was significantly (p < .05) reduced by all tested concentrations of this peptide, the most cytotoxic effects being observed at the highest PG1 concentrations. Despite these results, the use of PG1 as an alternative to antibiotics cannot be totally discarded, as further studies using the truncated form of this peptide are needed.

First evidence for the presence of aquaporins in stallion sperm.

Aquaporins (AQPs) are transmembrane proteins found in all cells and are responsible for the transport of water and small solutes. While these proteins have been found in the spermatozoa of humans, rodents, pigs and cattle, where not only do they play a role for the regulation of sperm volume but are also related with the sperm resilience to withstand freeze-thawing procedures, their presence in stallion sperm is yet to be reported. Therefore, the objectives of this work were as follows: (i) to determine whether AQP3, AQP7 and AQP11 are present in stallion sperm and (ii) to investigate whether the relative amounts of these three AQPs play any role in the cryopreservation success. With this purpose, a total of five ejaculates from healthy stallions were collected. Evaluation of sperm quality and immunoblotting against these three proteins were performed before and after cryopreservation. Immunoblots confirmed the presence of AQP3, AQP7 and AQP11 in all examined samples. Subsequently, ejaculates were classified as GFE (good) and PFE (poor freezability ejaculates), according to their sperm viability and motility at 0 and 2 hr post-thaw. Relative AQP3 and AQP11 contents in stallion fresh semen were found to be significantly (p < .05) higher in GFE than in PFE. In conclusion, the current study has confirmed, for the first time, the presence of AQP3, AQP7 and AQP11 in stallion sperm. In addition, despite preliminary, our results suggest that AQP3 and AQP11 are involved in the resilience of stallion sperm to withstand cryopreservation. Ongoing research is aimed at increasing the sample size and includes immunolocalization studies.

Voltage-dependent anion channel 2 is involved in in vitro capacitation of boar sperm.

Ion channels play an important role during sperm capacitation allowing the transport through plasma and mitochondrial membranes of specific molecules that are essential for the achievement of this physiologic status. Given that voltage-dependent anion channel 2 (VDAC2) is present in boar spermatozoa and is known to be involved in calcium transport in somatic cells, this study aimed at determining whether it is implicated in sperm capacitation and the acrosome reaction. With this purpose, boar spermatozoa were capacitated in vitro for 4 hr, and acrosome reaction was induced with progesterone for a further hour, with or without the presence of two VDAC2-inhibitors (erastin and olesoxime) at two different concentrations (10 and 100 µM). At different time points (0, 120, 240, 270 and 300 min), an aliquot was taken and sperm motility, membrane integrity and lipid disorder were evaluated using computer-assisted sperm analysis and flow cytometry. The addition of the two inhibitors resulted in opposite effects. While erastin 100 µM reduced the percentage of non-capacitated spermatozoa, the presence of olesoxime at the same concentration prevented the increase in membrane lipid disorder, which is a feature of sperm capacitation. Such prevention was concomitant with a maintaining effect on sperm membrane integrity evaluated through SYBR14/PI. Our results suggest that VDAC2 is involved in the regulation of sperm capacitation, despite the fact that the mechanisms through which erastin and olesoxime act are different.

Aquaporins in the male reproductive tract and sperm: Functional implications and cryobiology.

Aquaporins (AQPs) play a vital role for the transport of water and solutes across cell membranes. Classification of these ubiquitous proteins into three categories (orthodox AQPs, aquaglyceroporins and superaquaporins) is based on their sequence similarity and substrate selectivity. In the male reproductive tract of mammals, most AQPs (except AQP6 and AQP12) are found in different organs (including testis, efferent ducts and epididymis). AQP1 and AQP9 are the most abundant AQPs in the efferent ducts and epididymis and play a crucial role for the secretion/reabsorption dynamics of luminal fluid during sperm transport and maturation. AQP3, AQP7, AQP8 and AQP11 are the most abundant AQPs in sperm and are involved in the regulation of their volume, which is required for the differentiation of spermatids into spermatozoa during spermatogenesis, as well as in sperm transit along environments of different osmolality (male and female reproductive tracts). While different studies conducted in oocytes and embryos have demonstrated that AQPs are important for cryotolerance, data in sperm are scarce. At present, mounting evidence indicates that AQP3, AQP7 and AQP11 are involved in the sperm response to variations of osmolality and to freeze-thawing procedures. All these studies contribute to understand the physiology of both male reproductive tract and sperm, and open up new research ventures on the improvement of sperm cryopreservation protocols.

Relationship of aquaporins 3 (AQP3), 7 (AQP7), and 11 (AQP11) with boar sperm resilience to withstand freeze-thawing procedures.

Cryopreservation is the most suitable method to preserve boar spermatozoa over long-term storage. However, freeze-thawing protocols inflict extensive damage to sperm cells, reducing their viability and compromising their fertilizing ability. In addition, high individual variability is known to exist between boar ejaculates, which may be classified as of good (GFE) or poor (PFE) freezability. While conventional spermiogram parameters fail to predict sperm cryotolerance in fresh spermatozoa, high levels of certain proteins, also known as freezability markers, have been found to be related to the sperm resilience to withstand freeze-thawing procedures. In this context, the hypothesis of this study was that aquaporins AQP3, AQP7, and AQP11 could be linked to boar sperm cryotolerance. Twenty-nine ejaculates were evaluated and subsequently classified as GFE or PFE based upon their sperm viability and motility at post-thawing. Fourteen ejaculates resulted to be GFE, whereas the other fifteen were found to be PFE. Relative abundances of AQP3, AQP7, and AQP11 and their localization patterns were evaluated in all fresh and frozen-thawed ejaculates through immunoblotting and immunocytochemistry. Prior to cryopreservation, relative amounts of AQP3 and AQP7 were found to be significantly (p < 0.05) higher in GFE than in PFE. In contrast, no significant differences (p > 0.05) between freezability groups were found for AQP11, despite GFE tending to present higher levels of this protein. The localization of AQP7, but not that of AQP3 or AQP11, was observed to be affected by cryopreservation procedures. In conclusion, these results suggest that AQP3 and AQP7 are related to boar sperm cryotolerance and may be used as freezability markers.

Toxicity of TiO2, in nanoparticle or bulk form to freshwater and marine microalgae under visible light and UV-A radiation.

Use of titanium dioxide nanoparticles (TiO2 NPs) has become a part of our daily life and the high environmental concentrations predicted to accumulate in aquatic ecosystems are cause for concern. Although TiO2 has only limited reactivity, at the nanoscale level its physico-chemical properties and toxicity are different compared with bulk material. Phytoplankton is a key trophic level in fresh and marine ecosystems, and the toxicity provoked by these nanoparticles can affect the structure and functioning of ecosystems. Two microalgae species, one freshwater (Chlamydomonas reinhardtii) and the other marine (Phaeodactylum tricornutum), have been selected for testing the toxicity of TiO2 in NP and conventional bulk form and, given its photo-catalytic properties, the effect of UV-A was also checked. Growth inhibition, quantum yield reduction, increase of intracellular ROS production, membrane cell damage and production of exo-polymeric substances (EPS) were selected as variables to measure. TiO2 NPs and bulk TiO2 show a relationship between the size of agglomerates and time in freshwater and saltwater, but not in ultrapure water. Under two treatments, UV-A (6 h per day) and no UV-A exposure, NPs triggered stronger cytotoxic responses than bulk material. TiO2 NPs were also associated with greater production of reactive oxygen species and damage to membrane. However, microalgae exposed to TiO2 NPs and bulk TiO2 under UV-A were found to be more sensitive than in the visible light condition. The marine species (P. tricornutum) was more sensitive than the freshwater species, and higher Ti internalization was measured. Exopolymeric substances (EPS) were released from microalgae in the culture media, in the presence of TiO2 in both forms. This may be a possible defense mechanism by these cells, which would enhance processes of homoagglomeration and settling, and thus reduce bioavailability.

Direct and indirect effects of silver nanoparticles on freshwater and marine microalgae (Chlamydomonas reinhardtii and Phaeodactylum tricornutum).

The last decade has seen a considerable increase in the use of silver nanoparticles (AgNPs), which are found in many every-day consumer products including textiles, plastics, cosmetics, household sprays and paints. The release of those AgNPs into aquatic environments could be causing ecological damage. In this study we assess the toxicity of AgNPs of different sizes to two species of microalgae, from freshwater and marine environment (Chlamydomonas reinhardtii and Phaeodactylum tricornutum respectively). Dissolution processes affect the form and concentration of AgNPs in both environments. Dissolution of Ag from AgNPs was around 25 times higher in marine water. Nevertheless, dissolution of AgNPs in both culture media seems to be related to the small size and higher surface area of NPs. In marine water, the main chemical species were AgCl2- (53.7%) and AgCl3-2 (45.2%). In contrast, for freshwater, the main chemical species were Ag+ (26.7%) and AgCl- (4.3%). The assessment of toxicological responses, specifically growth, cell size, cell complexity, chlorophyll a, reactive oxygen species, cell membrane damage and effective quantum yield of PSII, corroborated the existence of different toxicity mechanisms for microalgae. Indirect effects, notably dissolved Ag ions, seem to control toxicity to freshwater microalgae, whereas direct effects, notably attachment onto the cell surface and the internalization of AgNPs inside cells, seem to determine toxicity to the marine species studied. This research contributes to knowledge on the role of intrinsic and extrinsic factors in determining the behavior of NPs in different aquatic environments and the interaction with microalgae.

Homoagglomeration and heteroagglomeration of TiO2, in nanoparticle and bulk form, onto freshwater and marine microalgae.

TiO2 nanoparticles (TiO2 NPs) are employed in many products (paints, personal care products, especially sunscreens, plastics, paper, water potabilization and food products) and are then released into the environment from these products. These nanoparticles present potential risk to freshwater and marine microalgae. The primary toxicity mechanism is adsorption between NPs and microalgae (heteroagglomeration); however, studies of interactions of this kind are scarce. We investigated the heteroagglomeration process that occurs between two forms of TiO2 material, nanoparticles and bulk, and three different microalgae species, and under different environmental conditions (freshwater and marine water), in order to assess the influence of pH and ionic strength (IS). The heteroagglomeration process was examined by means of co-settling experiments and the Derjaguin-Landau-Verwey-Overbeek (DLVO) approach. The homoagglomeration process (only NPs to NPs) did not show differences between culture media (freshwater and marine water). However, in the heteroagglomeration process between NPs and cells, IS played an important role. Ions can compress the electro-double layer between NPs and microalgae, allowing a heteroagglomeration process to take place, as shown by settling experiments. TiO2 NPs presented a settling rate higher than bulk TiO2. The DLVO theory could only partially explain heteroagglomeration because, in this model, it is not considered that NP-NP and Cell-Cell homoagglomeration co-occur. In this study neither the role of exopolymeric substances in the interaction between NPs and cells nor detoxification are considered. The authors suggest that the interaction between NPs and microalgae could be considered as the first stage in the process by which nanoparticles affect microalgae.

[Comparability study of analytical results between a group of clinical laboratories]. / Intercambiabilidad de resultados entre los diferentes laboratorios clínicos Catlab.

OBJECTIVE: To describe the study of the comparability of the measurements levels of biological tests processed in biochemistry in Catlab's 4 laboratories. MATERIAL AND METHODS: Quality requirements, coefficients of variation and total error (CV% and TE %) were established. Controls were verified with the precision requirements (CV%) in each test and each individual laboratory analyser. Fresh serum samples were used for the comparability study. The differences were analysed using a Microsoft Access® application that produces modified Bland-Altman plots. RESULTS: The comparison of 32 biological parameters that are performed in more than one laboratory and/or analyser generated 306 Bland-Altman graphs. Of these, 101 (33.1%) fell within the accepted range of values based on biological variability, and 205 (66.9%) required revision. Data were re-analysed based on consensus minimum specifications for analytical quality (consensus of the Asociación Española de Farmacéuticos Analistas (AEFA), the Sociedad Española de Bioquímica Clínica y Patología Molecular (SEQC), the Asociación Española de Biopatología Médica (AEBM) and the Sociedad Española de Hematología y Hemoterapia (SEHH), October 2013). With the new specifications, 170 comparisons (56%) fitted the requirements and 136 (44%) required additional review. Taking into account the number of points that exceeded the requirement, random errors, range of results in which discrepancies were detected, and range of clinical decision, it was shown that the 44% that required review were acceptable, and the 32 tests were comparable in all laboratories and analysers. CONCLUSIONS: The analysis of the results showed that the consensus requirements of the 4 scientific societies were met. However, each laboratory should aim to meet stricter criteria for total error.

[UNE-EN ISO 15189 accreditation of the preanalytical phase of a clinical laboratory]. / Acreditación según la norma UNE-EN ISO 15189, de la fase preanalítica del laboratorio de análisis clínicos Catlab.

OBJECTIVES: Description of the procedures followed in Catlab's pre-analytical area for UNE-EN ISO 15189 accreditation, and implementation of quality indicators to evaluate the standard requirements in the pre-analytical phase processes. MATERIAL AND METHODS: Description of Catlab's 2 self-developed computer applications: Catlab Program Incidents (CPI) and Refrigerator Management Program (RMP). Both of them, among other applications, documentation and quality indicators, had enabled us to achieve UNE-EN ISO 15189 accreditation and have traceability in the pre-analytical phase. RESULTS: Results of 4 quality indicators are shown. In the customers satisfaction measurement indicator, 97.3% clinicians value positively (quite/lot) different aspects of the laboratory. The indicator of pre-analytical incidents went from 7.2% in 2011 down to 4.4% in 2014. In the prompt transport of late arrival samples, 3 of the routes (33%) did not reach the acceptable target. And finally, the indicator of default opening time of sample coolers, 100% of the routes reached the desired objective in the second quarter of 2014. CONCLUSIONS: The use of those applications, allowed us to design quality control indicators of the processes in the pre-analytical phase; from sample extraction to its analytical process in the laboratory, enhancing the collaboration with extraction sites, and allowing improvement actions to be established.

Recent Advances in Boar Sperm Cryopreservation: State of the Art and Current Perspectives.

While sperm cryopreservation is the best technology to store boar semen for long-term periods, only 1% of all artificial inseminations (AI) conducted worldwide are made using frozen-thawed boar sperm. With the emergence of long-term extenders for liquid storage, the use of cryopreserved sperm in routine AI is less required. However, banks of boar semen contain cryopreserved sperm and planning inseminations in AI centres may benefit from the use of frozen-thawed semen. Therefore, there is an interest in the use of this technology to preserve boar sperm. In this regard, although the first attempts to cryopreserve boar semen date back to the seventies and this technology is still considered as optimal, some relevant improvements have been made in the last decade. After giving a general picture about boar sperm cryodamage, the present review seeks to shed light on these recent cryopreservation advances. These contributions regard to protein markers for predicting ejaculate freezability, sperm selection prior to start cryopreservation procedures, additives to freezing and thawing extenders, relevance of the AI-technique and insemination-to-ovulation interval. In conclusion, most of these progresses have allowed counteracting better boar sperm cryodamage and are thus considered as forward steps for this storage method. It is also worth noting that, despite being lower than fresh/extended semen, reproductive performance outcomes following AI with frozen-thawed boar sperm are currently acceptable.