Magnetic nanoparticles with bulk-like properties

The magnetic behavior of $Fe_{3-x}O_4$ nanoparticles synthesized either by high-temperature decomposition of an organic iron precursor or low-temperature co-precipitation in aqueous conditions, is compared. Transmission electron microscopy, X-ray absorption spectroscopy, X-ray magnetic circular dichroism and magnetization measurements show that nanoparticles synthesized by thermal decomposition display high crystal quality and bulk-like magnetic and electronic properties, while nanoparticles synthesized by co-precipitation show much poorer crystallinity and particle-like phenomenology, including reduced magnetization, high closure fields and shifted hysteresis loops. The key role of the crystal quality is thus suggested since particle-like behavior for particles larger than about 5 nm is only observed when they are structurally defective. These conclusions are supported by Monte Carlo simulations. It is also shown that thermal decomposition is capable of producing nanoparticles that, after further stabilization in physiological conditions, are suitable for biomedical applications such as magnetic resonance imaging or bio-distribution studies.Comment: Review article. 20 pages, 7 figures. Invited contribution to 55th MMM Conference 2010 (Atlanta), Session HG-01. To be published in J. Appl. Phy

Exploring the embryonic development of upper beak in Octopus vulgaris Cuvier, 1797: New findings and implications for age estimation

The beak of cephalopods (in particular octopods, where statoliths are not suitable) is a useful tool for age estimation and the aging method provides essential information on cephalopod growth and life cycles. These parameters are valuable in the assessment of population dynamics and stock management. The embryonic development of cephalopod beaks is poorly known. The presence of pre-hatching increments on the reading areas (rostrum and lateral walls) is unclear and there are no data on temperature influence. In this study, egg clusters of Octopus vulgaris were reared at 16, 19, 21, 23, and 26 °C. The extracted upper jaws were observed in order to validate the age of first daily increment formation, assessing the accuracy of age inferred from the two reading areas. Jaw dimensions were also measured in order to explore the development at different temperature conditions. The growth rate was calculated for beaks of rearing condition 21 °C, and the overall dimensions were compared among all incubation temperatures. Three ad hoc developmental stages are proposed for the upper beak of O. vulgaris embryos. Increments on lateral walls appear during the second phase, whereas the first increment on the rostrum is visible only at hatching. Consequently, only the accuracy of age inferred from the rostrum surface is confirmed for the early stages. The growth rate of the rostrum region accounted for a drop in growth during the third phase. Conversely, the growth rate increased until hatching in lateral walls, suggesting that the heterogeneity of the growth rate could be due to the different role played by the beak areas. Temperature influenced beaks in terms of overall size, as embryos reared at a warm temperature (23 °C) were smaller than the others. These results confirm that the incubation environment could alter hatchling characteristics thus affecting the recruitment conditions.Postprint1,58

Strategies for greenhouse gas emissions mitigation in Mediterranean agriculture: A review

[EN] An integrated assessment of the potential of different management practices for mitigating specific components of the total GHG budget (N2O and CH4 emissions and C sequestration) of Mediterranean agrosystems was performed in this study. Their suitability regarding both yield and environmental (e.g. nitrate leaching and ammonia volatilization) sustainability, and regional barriers and opportunities for their implementation were also considered. Based on its results best strategies to abate GHG emissions in Mediterranean agro-systems were proposed. Adjusting N fertilization to crop needs in both irrigated and rain-fed systems could reduce N2O emissions up to 50% compared with a non-adjusted practice. Substitution of N synthetic fertilizers by solid manure can be also implemented in those systems, and may abate N2O emissions by about 20% under Mediterranean conditions, with additional indirect benefits associated to energy savings and positive effects in crop yields. The use of urease and nitrification inhibitors enhances N use efficiency of the cropping systems and may mitigate N2O emissions up to 80% and 50%, respectively. The type of irrigation may also have a great mitigation potential in the Mediterranean region. Drip-irrigated systems have on average 80% lower N2O emissions than sprinkler systems and drip-irrigation combined with optimized fertilization showed a reduction in direct N2O emissions up to 50%. Methane fluxes have a relatively small contribution to the total GHG budget of Mediterranean crops, which can mostly be controlled by careful management of the water table and organic inputs in paddies. Reduced soil tillage, improved management of crop residues and agro-industry by-products, and cover cropping in orchards, are the most suitable interventions to enhance organic C stocks in Mediterranean agricultural soils. The adoption of the proposed agricultural practices will require farmers training. The global analysis of life cycle emissions associated to irrigation type (drip, sprinkle and furrow) and N fertilization rate (100 and 300 kg N ha(-1) yr(-1)) revealed that these factors may outweigh the reduction in GHG emissions beyond the plot scale. The analysis of the impact of some structural changes on top-down mitigation of GHG emissions revealed that 3-15% of N2O emissions could be suppressed by avoiding food waste at the end-consumer level. A 40% reduction in meat and dairy consumption could reduce GHG emissions by 20-30%. Reintroducing the Mediterranean diet (i.e. similar to 35% intake of animal protein) would therefore result in a significant decrease of GHG emissions from agricultural production systems under Mediterranean conditions. (C) 2016 Elsevier B.V. All rights reserved.The authors would like to thank the Spanish National R+D+i Plan (AGL2012-37815-C05-01, AGL2012-37815-C05-04) and very specifically the workshop held in December 2016 in Butron (Bizkaia) to synthesize the most promising measures to reduce N2O emissions from Spanish agricultural soils. BC3 is sponsored by the Basque Government. M. L. Cayuela thanks Fundacion Seneca for financing the project 19281/PI/14.Sanz-Cobeña, A.; Lassaletta, L.; Aguilera, E.; Del Prado, A.; Garnier, J.; Billen, G.; Iglesias, A.... (2017). Strategies for greenhouse gas emissions mitigation in Mediterranean agriculture: A review. Agriculture Ecosystems & Environment. 238:5-24. https://doi.org/10.1016/j.agee.2016.09.038S52423

Procalcitonin is not sufficiently reliable to be the sole marker of neonatal sepsis of nosocomial origin

BACKGROUND: It has recently been suggested that serum procalcitonin (PCT) is of value in the diagnosis of neonatal sepsis, with varying results. The aim of this prospective multicenter study was to assess the usefulness of PCT as a marker of neonatal sepsis of nosocomial origin. METHODS: One hundred infants aged between 4 and 28 days of life admitted to the Neonatology Services of 13 acute-care teaching hospitals in Spain over 1-year with clinical suspicion of neonatal sepsis of nosocomial origin were included in the study. Serum PCT concentrations were determined by a specific immunoluminometric assay. The reliability of PCT for the diagnosis of nosocomial neonatal sepsis at the time of suspicion of infection and at 12–24 h and 36–48 h after the onset of symptoms was calculated by receiver-operating characteristics (ROC) curves. The Youden's index (sensitivity + specificity - 1) was used for determination of optimal cutoff values of the diagnostic tests in the different postnatal periods. Sensitivity, specificity, and the likelihood ratio of a positive and negative result with the 95% confidence interval (CI) were calculated. RESULTS: The diagnosis of nosocomial sepsis was confirmed in 61 neonates. Serum PCT concentrations were significantly higher at initial suspicion and at 12–24 h and 36–48 h after the onset of symptoms in neonates with confirmed sepsis than in neonates with clinically suspected but not confirmed sepsis. Optimal PCT thresholds according to ROC curves were 0.59 ng/mL at the time of suspicion of sepsis (sensitivity 81.4%, specificity 80.6%); 1.34 ng/mL within 12–24 h of birth (sensitivity 73.7%, specificity 80.6%), and 0.69 ng/mL within 36–48 h of birth (sensitivity 86.5%, specificity 72.7%). CONCLUSION: Serum PCT concentrations showed a moderate diagnostic reliability for the detection of nosocomial neonatal sepsis from the time of suspicion of infection. PCT is not sufficiently reliable to be the sole marker of sepsis, but would be useful as part of a full sepsis evaluation

RICORS2040 : The need for collaborative research in chronic kidney disease

Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true

Targeted delivery of immunotoxin by antibody to ganglioside GD3: a novel drug delivery route for tumor cells.

Gangliosides are sialic acid-containing glycolipids expressed on plasma membranes from nearly all vertebrate cells. The expression of ganglioside GD3, which plays essential roles in normal brain development, decreases in adults but is up regulated in neuroectodermal and epithelial derived cancers. R24 antibody, directed against ganglioside GD3, is a validated tumor target which is specifically endocytosed and accumulated in endosomes. Here, we exploit the internalization feature of the R24 antibody for the selective delivery of saporin, a ribosome-inactivating protein, to GD3-expressing cells [human (SK-Mel-28) and mouse (B16) melanoma cells and Chinese hamster ovary (CHO)-K1 cells]. This immunotoxin showed a specific cytotoxicity on tumor cells grew on 2D monolayers, which was further evident by the lack of any effect on GD3-negative cells. To estimate the potential antitumor activity of R24-saporin complex, we also evaluated the effect of the immunotoxin on the clonogenic growth of SK-Mel-28 and CHO-K1(GD3+) cells cultured in attachment-free conditions. A drastic growth inhibition (>80-90%) of the cell colonies was reached after 3 days of immunotoxin treatment. By the contrary, colonies continue to growth at the same concentration of the immuntoxin, but in the absence of R24 antibody, or in the absence of both immunotoxin and R24, undoubtedly indicating the specificity of the effect observed. Thus, the ganglioside GD3 emerge as a novel and attractive class of cell surface molecule for targeted delivery of cytotoxic agents and, therefore, provides a rationale for future therapeutic intervention in cancer