Exploiting the Reactivity of Metal Trifluoroacetates to Access Alkali-Niobium(V) Oxyfluorides.

Motivated by the lack of facile routes to alkali-niobium(V) oxyfluorides KNb2O5F and CsNb2O5F, we investigated the reactivity of alkali trifluoroacetates KH(tfa)2 and CsH(tfa)2 (tfa = CF3COO-) toward Nb2O5 in the solid state. Tetragonal tungsten bronze KNb2O5F and pyrochlore CsNb2O5F were obtained by simply reacting the corresponding trifluoroacetate with Nb2O5 at 600 °C under air, without the need for specialized containers or a controlled atmosphere. Thermolysis of KH(tfa)2 in the presence of Nb2O5 yielded single-phase polycrystalline KNb2O5F. By contrast, the reaction between CsH(tfa)2 and Nb2O5 produced a mixture of CsNb2O5F and a new oxyfluoride of formula CsNb3O7F2, whose crystal structure was solved using powder X-ray and electron diffraction. CsNb3O7F2 (space group P6/mmm) belongs to the family of hexagonal tungsten bronzes and features an open-framework structure consisting of corner-sharing Nb(O,F)6 octahedra with hexagonal channels occupied by Cs+ ions. Isomorphous RbNb3O7F2 was obtained upon reacting RbH(tfa)2 with Nb2O5. Synthetic optimization enabled the preparation of RbNb3O7F2 and CsNb3O7F2 as single-phase polycrystalline solids at 500 °C under flowing synthetic air. Both oxyfluorides were found to be semiconductors with a band gap of ≈3.5 eV. The discovery of these two oxyfluorides highlights the importance of probing the reactivity of solids whose full potential as fluorinated precursors is yet to be realized.

Tandem Triplication 11p15.5-ICR1 (H19/IGF2) Detected by Microarray and Optical Genome Mapping in a Prenatal Beckwith-Wiedemann Case.

Optical genome mapping (OGM) appears as a new tool for matching standard cytogenetic methods (karyotype and microarray) into a single assay. The chromosomal region 11p15.5 harbours two differentially methylated regions, the imprinting centre regions 1 and 2 (ICR1, ICR2). Disturbances in both regions alter human growth and are associated with two imprinting disorders, Beckwith-Wiedemann (BWS) and Silver-Russell syndromes. Herein, we present a prenatal case with a triplication in 11p15.5, including the H19/IGF2 imprinted region, detected by microarray and OGM. A 30-year-old pregnant woman of 17 weeks of gestation was referred for prenatal karyotype and microarray study because of increased nuchal translucency, short femur, megabladder, hyperechogenic bowel, and renal ectasia. Microarray, OGM, and MS-MLPA were performed, and a tandem cis-triplication in 11p15.5 and hypermethylation of the ICR1 region, compatible with BWS was detected. OGM, with its power to detect all classes of structural variants, including copy number variants, at a higher resolution than traditional cytogenetic methods can play a significant role in prenatal care and management as a next-generation cytogenomic tool. This study further supports the hypotheses that the amplification/duplication-triplication of the H19/IGF2 region could be related to BWS if it is of paternal origin.

Metal-to-Insulating Transition in the Perovskite System YSr2Cu2FeO8-δ (0 < δ < 1) Modeled by DFT Methods.

Progress in the design of functional perovskite oxides relies on advances in density functional theory (DFT) methods to efficiently and effectively model complex systems composed of several transition-metal ions. This work reports the application of DFT methods to investigate the electronic structure of the YSr2Cu2FeO8-δ (0 < δ < 1) family in which the insulating, metal, or superconducting behaviors and even anion conductivity can be tuned by modifying the oxygen content. In particular, we assess the performance of the generalized gradient approximation (GGA), its Hubbard-U correction (GGA + U), and the strongly constrained and appropriately normed (SCAN) to model the metallic (idealized YSr2Cu2FeO8) and insulating (idealized YSr2Cu2FeO7) phases of the system. The analysis of the DFT results is supported by DC resistivity measurements that denote the metal character of the synthesized YSr2Cu2FeO7.86 and the semiconducting character of YSr2Cu2FeO7.08 prepared under reducing conditions. In addition, the band gap of YSr2Cu2FeO7.08, in the range of 0.73-1.2 eV, has been extracted from diffuse reflectance spectroscopy (DRS). While the three methodologies (GGA, GGA + U, SCAN) permit the reproduction of the crystal structures of the synthetized oxides (determined here in the case of YSr2Cu2FeO7.08 by neutron powder diffraction (NPD)), the SCAN emerges as the only one capable to predict the basic electronic and magnetic properties across the YSr2Cu2FeO8-δ (0 < δ < 1) series. The picture that emerges for the metal (δ = 0) to insulating (δ = 1) transition is the one in which oxygen vacancies contribute electrons to the filling of the Cu/Fe-3dx2-y2 states of the conduction band. These results validate the SCAN functional for future DFT investigations of complex functional oxides that combine several transition metals.

Stability and Evolution of the Crystal Structure of TbBaCo2O6-δ During Thermal Oxygen Release/Uptake.

A-site ordered double perovskites with the general formula LnBaCo2O6-δ (where Ln is a lanthanide element) present electrical and electrocatalytic properties that make them attractive as possible ceramic electrode materials for solid oxide cells or alkaline electrolyzers. The properties are highly influenced by the anion vacancy concentration, which is strongly related to the Co-oxidation state, and their location in the structure. Awareness of the stable phases is essential to synthesize, evaluate, and optimize the properties of LnBaCo2O6-δ oxides at operating conditions in different applications. TbBaCo2O6-δ are representative oxides of these layered perovskite systems. The present article reports a study of TbBaCo2O6-δ by electron diffraction, high-resolution electron microscopy, and powder neutron diffraction experiments at different temperatures. The synthesis of TbBaCo2O6-δ in air and slow cooling to room temperature (RT) at 5 °C h-1 leads to samples formed by distinct phases with different oxygen contents and crystal structures. The 122 and 112 phases (with ap × 2ap × 2ap and ap × ap × 2ap unit cells, respectively, with ap being the lattice parameter of the simple cubic perovskite structure) are predominant in quasi-equilibrium prepared samples (cooled at RT at 1 °C h-1) or prepared in Ar flow and quenched to RT. The evolution of the crystal structure of TbBaCo2O6-δ during thermal oxygen release/uptaking consists of modulation from the 122 phase to the 112 phase (or vice versa during uptaking) by creation/occupation of anion vacancies within the TbO1-δ planes. Anion vacancies are not detected in the oxygen crystallographic position different from those located within the TbO1-δ planes even at the highest temperatures, supporting the 2D character of the high anion conduction of the LnBaCo2O6-δ oxides.

[Vaccination against the herpes zoster virus]. / Vacunación frente al virus del herpes zóster.

OBJECTIVE: To review the latest published evidence on the vaccine used in our country against the herpes zoster virus, breaking down the results according to the efficacy, efficiency, effectiveness and safety of the vaccine. Include the current recommendations for vaccination. DESIGN: Secondary review. Descriptive qualitative review. Review using the search term "herpes zoster vaccine" and "Adjuvanted recombinant Herpes Zoster subunit vaccine". Retrospective observational study. DATA SOURCES: Embase, Medline and Google Scholar. Selection of studies Search criterion with the terms "Shingrix vaccine" and "Adjuvanted Herpes Zoster Subunit Vaccine". Search period 2013-2023. Studies classified as clinical trials or randomized clinical trials were selected. 21 published studies were evaluated. There were no exclusions. RESULTS: The evaluated studies were found to be coherent and in all of them efficacy in adult individuals in preventing viral reactivation and in preventing complications was higher than 80%. The effectiveness of the vaccine after two doses was also higher than 80%. Cost-effectiveness studies were always favourable in adults, immunodepressed patients and individuals with chronic pathology. The safety of the vaccine was evaluated in the pivotal studies and in the post-commercialization studies that were undertaken (although there were few of the latter due to the short period of time studied). The safety profile of the vaccine is very high and in the case of severe adverse effects, their frequency was similar to that of a placebo. CONCLUSIONS: We have a safe and effective vaccine against the herpes zoster virus that allows us to protect the most vulnerable population groups against this virus.

Alcohol use and family-related factors among Spanish university students: the unHicos project.

BACKGROUND: During adolescence and youth there are relevant changes in the consolidation, gain or loss of consumption habits and lifestyles and the family factors has a fundamental role to development these habits. The study of the consumption of toxins, such as alcohol intake, is crucial at this stage due to the repercussions that said consumption presents in adulthood. Therefore, the objective of our study was to evaluate the associations between alcohol consumption patterns and related family factors (family functioning, family history of alcohol consumption) in Spanish university students. METHODS: Observational, descriptive, cross-sectional, multicenter study, carried out in first-year university students from 11 Spanish universities. Through an online questionnaire, alcohol consumption (risky consumption and intensive consumption or binge drinking), family functioning and history of alcohol in the family were evaluated. Risky alcohol consumption and binge drinking were assessed using the AUDIT test, and family functioning was assessed using the family APGAR questionnaire. A descriptive analysis of the data was performed, as well as the Chi-Square test and Student's T-Test, and non-conditional logistic regression models were carried out to examine this association. RESULTS: The prevalence of risky alcohol consumption identified in the 10,167 respondents was 16.9% (95% CI = 16.2-17.6), and that of BD was 48.8% (95% CI = 47.9-48.8). There is a significant association between risky alcohol consumption and family functioning in students of both sexes, with greater consumption in the face of severe dysfunctional support (men OR = 1.72; p < 0.001 and women OR = 1.74; p < 0.001) and family history of consumption (p = 0.005). Regarding the binge drinking pattern, no statistically significant differences were observed. CONCLUSIONS: Risky alcohol consumption in university students is associated with dysfunctional family support, unlike the binge drinking pattern, where there is no such association. The findings of this study show the importance of creating prevention programs focused on the family approach in university students, which include alcohol screening in the population with a family history of this substance, and greater social support from health services.

[Infectious Disease Prevention Group: Update on vaccines, 2022]. / Prevención de las enfermedades infecciosas. Actualización en vacunas PAPPS 2022.

The update of the preventive activities for this year 2022 in the field of infectious diseases is of special relevance due to the importance that prevention has gained and more specifically, vaccination as a tool to control the pandemic caused by the SARS-CoV-2 virus declared on March 11, 2020. The pandemic has focused much of the prevention efforts on its containment, but the importance of maintaining high vaccination coverage of the rest of the recommended vaccines to maintain good control of vaccine-preventable diseases and avoid complications in particularly vulnerable patients should not be forgotten. In this year's review we present a practical document with the aim of providing tools to primary care professionals who work with adults, to make the indication of each vaccine whether it is systematically recommended or if it is because the patient belongs to some risk group due to their condition or underlying pathology. In this way, throughout the document, we will comment on the most innovative aspects of systematic vaccination (flu, pneumococcus, meningococcal vaccines and vaccines against the human papillomavirus [HPV]), the new vaccines (pandemic vaccines against COVID-19, vaccines against herpes zoster of subunits, vaccines against monkeypox) and the recommended vaccines according to risk condition (pregnancy and lactation, travelers, patients with immunosuppression or underlying pathology).

Coupled Compositional and Displacive Modulations in KLaMnWO6 Revealed by Atomic Resolution Imaging.

Complex compositional and displacive modulations of the crystal structure of KLaMnWO6 are imaged with atomic resolution by means of scanning transmission electron microscopy (STEM). This oxide is stabilized by cation vacancies leading to a La1+x/3K1-xMnWO6 stoichiometry. Compositional modulation on both the K and La layers are revealed in the high-angle annular dark-field STEM (HAADF-STEM) images. The compositional modulation within the La layer is coupled with the modulation of the octahedral tilting, which is exposed by imaging of the anion sublattice in annular bright-field STEM (ABF-STEM) images. These complex modulations are accommodated in a 5√2ap × 5√2ap × 2ap perovskite-type structure.

3D to 2D Magnetic Ordering of Fe3+ Oxides Induced by Their Layered Perovskite Structure.

The antiferromagnetic behavior of Fe3+ oxides of composition RE1.2Ba1.2Ca0.6Fe3O8, RE2.2Ba3.2Ca2.6Fe8O21, and REBa2Ca2Fe5O13 (RE = Gd, Tb) is highly influenced by the type of oxygen polyhedron around the Fe3+ cations and their ordering, which is coupled with the layered RE/Ba/Ca arrangement within the perovskite-related structure. Determination of the magnetic structures reveals different magnetic moments associated with Fe3+ spins in the different oxygen polyhedra (octahedron, tetrahedron, and square pyramid). The structural aspects impact on the strength of the Fe-O-Fe superexchange interactions and, therefore, on the Néel temperature (TN) of the compounds. The oxides present an interesting transition from three-dimensional (3D) to two-dimensional (2D) magnetic behavior above TN. The 2D magnetic interactions are stronger within the FeO6 octahedra layers than in the FeO4 tetrahedra layers.

Up-regulation of HDACs, a harbinger of uraemic endothelial dysfunction, is prevented by defibrotide.

Endothelial dysfunction is an earlier contributor to the development of atherosclerosis in chronic kidney disease (CKD), in which the role of epigenetic triggers cannot be ruled out. Endothelial protective strategies, such as defibrotide (DF), may be useful in this scenario. We evaluated changes induced by CKD on endothelial cell proteome and explored the effect of DF and the mechanisms involved. Human umbilical cord vein endothelial cells were exposed to sera from healthy donors (n = 20) and patients with end-stage renal disease on haemodialysis (n = 20). Differential protein expression was investigated by using a proteomic approach, Western blot and immunofluorescence. HDAC1 and HDAC2 overexpression was detected. Increased HDAC1 expression occurred at both cytoplasm and nucleus. These effects were dose-dependently inhibited by DF. Both the HDACs inhibitor trichostatin A and DF prevented the up-regulation of the endothelial dysfunction markers induced by the uraemic milieu: intercellular adhesion molecule-1, surface Toll-like receptor-4, von Willebrand Factor and reactive oxygen species. Moreover, DF down-regulated HDACs expression through the PI3/AKT signalling pathway. HDACs appear as key modulators of the CKD-induced endothelial dysfunction as specific blockade by trichostatin A or by DF prevents endothelial dysfunction responses to the CKD insult. Moreover, DF exerts its endothelial protective effect by inhibiting HDAC up-regulation likely through PI3K/AKT.

Paroxysmal headache with extracephalic irradiation: Proposal for a new variant of epicrania fugax in a series of five patients.

BACKGROUND: Epicrania fugax consists of brief paroxysms of pain, which radiate in a line or in zigzag trajectory across the surface of the scalp or the face. METHODS: A prospective, descriptive study was performed in five patients presenting with an epicrania fugax-type pain with extracephalic irradiation. RESULTS: All patients were women, and the mean age at onset was 59.8 (standard deviation, 10.9). They had unilateral paroxysms of electrical pain starting at a particular point in the head (parietal, n = 3; vertex, n = 1; frontal, n = 1) and rapidly radiating downwards in a lineal trajectory to reach extracephalic regions (ipsilateral limbs, n = 2; shoulder, n = 2; low neck, n = 1) in 1-3 seconds. Pain intensity was moderate or severe. Three patients had nummular headache at the point where the paroxysms originated. One patient had spontaneous remission, and four patients achieved complete or almost complete response with therapy (onabotulinumtoxinA, n = 2; indomethacin, n = 1; amitriptyline, n = 1; lamotrigine, n = 1). CONCLUSION: The spectrum of epicrania fugax may include paroxysms with extracephalic irradiation. The propagation of pain beyond the head and the face supports the involvement of central mechanisms in the pathophysiology of this entity.

Structural Ordering Supremacy on the Oxygen Reduction Reaction of Layered Iron-Perovskites.

Layered perovskites of the Gd0.8-xBa0.8Ca0.4+xFe2O5+δ system show oxygen reduction reaction (ORR) activity. The layered crystal structure of these oxides is established by the interplay of the Gd3+, Ba2+, and Ca2+ locations with the ordering of the coordination polyhedra of the Fe3+ cations. Substitution of Gd3+ by Ca2+ increases the oxygen deficiency that is accommodated by the formation of layers of FeO5-squared pyramids intercalated with A-O layers containing mainly Gd3+. The presence of FeO5-squared pyramids in the crystal structure promotes the oxygen diffusion and then the ORR activity. Therefore, GdBa2Ca2Fe5O13 is the oxide of the system which presents lower area specific resistance (ASR) values when it is applied as an electrode in symmetrical cells using Ce0.9Gd0.1O2-δ as an electrolyte.

Successive and Site-Selective Oxygen Release from B-Site-Layer-Ordered Double Perovskite Ca2FeMnO6 with Unusually High Valence Fe4.

B-site-layer-ordered double perovskite Ca2FeMnO6 with unusually high valence Fe4+ was found to exhibit unusual oxygen-release behaviors, contrasting with those of the B-site-disordered perovskite having the identical chemical composition. During heating, the B-site-layer-ordered compound shows a stepwise oxygen release with successive valence changes from Fe4+ to Fe3+ through an intermediate Fe3.5+, whereas the B-site-disordered compound releases oxygen in a single step. The oxygen in Ca2FeMnO6 is released only from the two-dimensional Fe layers, and this selective oxygen release stabilizes the intermediate Fe3.5+ phase with in-plane-oxygen-vacancy ordering. Therefore, the B-site order/disorder strongly affects the oxygen-release behaviors associated with the oxygen-vacancy ordering.

[Infectious Disease Prevention Group. Update on vaccines, 2020]. / Prevención de las enfermedades infecciosas. Actualización en vacunas, 2020.

Vaccine development is one of the fastest growing sectors in medicine now and in the future, as we are living with the emergency health care for the SARS-CoV-2 coronavirus. The semFYC PAPPS program biannually publishes the recommendations of the group and, in this edition, special emphasis is placed on the common vaccination proposed by the Ministry of Health, where, at last, it no longer discriminates between paediatrics and adults, and proposes a calendar throughout life. The main novelties in the field of vaccinology today are focused on the consolidation of the nonavalent vaccine against the human papilloma virus and in the change of the dose of monovalent meningitis vaccine C for the tetravalent one, ACWY, at age 12. The pandemic we are experiencing has led to the postponement of most preventive activities. On the return to «normality¼, the vaccination calendar must be examined, and completed if necessary.

Initial results of the preventive Ícaro- Alcohol Programme.

Harmful alcohol consumption among young people is a public health problem that needs important measures. Interventions in emergency department cases, such as crisis action, could be effective. The initial results of the Icaro-Alcohol Program (detection of young people under 22 years attended in the emergency department for alcohol consumption, a Brief Motivational Intervention (BMI) and referral to a prevention reference service (PRS) and prevention programs) are presented. The program objective is to reduce the harmful use of alcohol. Río Hortega University Hospital (HURH), Clínico Hospital (HCUV) and Medical Emergency Units (MEUs) were involved in the study developed in the city of Valladolid (Castilla y León, Spain). Training in program implementation was given to 53.8% of professionals (n=27) (73.3% HURH vs 45.6% HCUV), while 17.4% (n=41) were trained to develop BMI in the critical situation derived from the emergency (26.7% HURH vs 12.6% HCUV). A total of 93 cases were treated by the hospital emergency services, and all the cases treated by the MEUs were referred to the hospital, between June and December 2017. There were 49 urgent cases, and interventions were carried out in 21 of them (43%). Afterwards, 8 cases were referred to the PRS (38% of 21 intervened; 16% of the total number of cases). Interventions and referrals were greater in the hospital with more trained professionals. The older youth cases arrived last at night. They had other health problems associated and were less likely to agree to referral. The referral times to indicated prevention programs were met, but not to universal and selective programs. The action protocol is improved by focusing on children under 18, simplifying consent, improving BMI training, simplifying the intervention of professionals and carrying out individual preventive intervention from the PRSs immediately. The program will be implemented progressively in the rest of the provinces in Castilla y León.

Expanding the Doubly Cation Ordered AA'BB'O6 Perovskite Family: Structural Complexity in NaLaInNbO6 and NaLaInTaO6.

Two new perovskite compounds, NaLaInNbO6 and NaLaInTaO6, have been synthesized. Both compounds have a rock-salt ordering of the In/Nb or In/Ta cations and a layered ordering of the Na/La. They are unusual among this family of doubly cation ordered perovskites for having a +3/+5 combination of B/B' oxidation states instead of a divalent cation and W6+. Synchrotron powder diffraction and electron diffraction data show both compounds have tetragonal √2ap × âˆš2ap × 2ap unit cells. The octahedral tilt system of these compounds is complicated and seems to vary depending on the length scale considered. Bond valence considerations demonstrate that none of the tilt systems compatible with a tetragonal unit cell produce a stable structure. It is proposed that additional oxygen displacements are occurring on a local scale. The XRD data show that the B-site ordering is nearly complete in both cases, while the A-site cations show a lower degree of order. The tendency of the B'-cation to undergo a second order Jahn-Teller distortion is identified as having an influence over the degree of A-site ordering. Transmission electron microscopy shows fragmentation into nanosized domains with perpendicular orientations of the layered A-site cation ordering. Such structures may be polar over short length scales which could lead to interesting dielectric properties such as relaxor behavior. The prospects for finding new doubly cation ordered perovskites are also discussed.

Influence of Structural (Cation and Anion) Order in the Superconducting Properties of Ozone-Oxidized Mo0.3Cu0.7Sr2RECu2O y (RE = Yb, Tm, Gd, Nd, and Pr).

The influence of rare earth (RE) elements on superconducting properties of the transition element (TE)-substituted TE xCu1- xSr2RECu2O y cuprates has not been sufficiently emphasized so far. In the case of molibdo-cuprates with the general formula Mo0.3Cu0.3Sr2RECu2O y, all the RE element containing compounds except La, Ce, and Lu can be prepared at room pressure. The influence of the crystal structure on the superconducting properties after ozone oxidation of the present system is reported selecting three groups of RE elements attending to their different atom sizes: small (Yb and Tm), medium (Gd), and big (Nd and Pr). Advanced transmission electron microscopy, various diffraction techniques, and spectroscopic analysis have been used to demonstrate that the increase of structural disorder complemented with a decrease in the hole content play a major role in the vanishing of superconductivity within the present system.

Mixed-Valence Iron Dumortierite Fe13.52.22+(As5+O4- x)8(OH)6 and Its Intricate Topotactic Exsolution at Mild Temperatures.

The mixed-valent iron arsenate hydroxide Fe13.52.22+(AsO4- x)8(OH)6, x = 0.25, was prepared using the reaction of iron metal with arsenate in aqueous solution and autogenous pressure. Its crystal structure reveals a dumortierite-like framework with mixed-valent Fe2+/Fe3+ in double chains creating channel walls. Remarkably, hexagonal channels consist of chains of face-sharing Fe2+O6 octahedra, 3/4th occupied, whereas AsO4 tetrahedra occupy triangular ones with a single " up" orientation according to the polar P63 mc symmetry. We have analyzed the transformation of this phase upon heating, in which several chemical processes interact, including dehydroxylation, arsenate to arsenite reduction, and oxidative exsolution of a significant part of iron (ca. 15%) found at the surface as hematite and amorphous Fe-rich surficial layer. It leaves a strongly disordered composite structure between several Fe3+-based subunits, in which ∼80% of them is ordered in a complex supercell. Because of the high degree of disorder, the crystal chemistry of the individual subunits and their plausible imbrication were considered to unravel the most plausible ideal 3D model.

[Inappropriate actions in adult vaccination]. / Actuaciones inadecuadas en vacunación de adultos.

Vaccines constitute one of the main foundations of the public health system, improving the quality and life expectancy of people. The vaccination calendar must be extended to the whole life of a person and in recent years the vaccination of the adult has become more complex and requires a greater knowledge of it. The role of primary care health is essential in order to improve vaccination coverage given the patient's closeness and trust. It is important to know the recommendations on vaccination for reasons of age, underlying pathology, work circumstances or any other factor that may endanger health and be preventable by vaccination and at the same time have clear criteria of what should not be done in this countryside. An excess in vaccination can pose a risk to the health of the patient and a waste of resources.

Crystal Structures at Atomic Resolution of the Perovskite-Related GdBaMnFeO5 and Its Oxidized GdBaMnFeO6.

Perovskite-related GdBaMnFeO5 and the corresponding oxidized phase GdBaMnFeO6, with long-range layered-type ordering of the Ba and Gd atoms have been synthesized. Oxidation retains the cation ordering but drives a modulation of the crystal structure associated with the incorporation of the oxygen atoms between the Gd layers. Oxidation of GdBaMnFeO5 increases the oxidation state of Mn from 2+ to 4+, while the oxidation state of Fe remains 3+. Determination of the crystal structure of both GdBaMnFeO5 and GdBaMnFeO6 is carried out at atomic resolution by means of a combination of advanced transmission electron microscopy techniques. Crystal structure refinements from synchrotron X-ray diffraction data support the structural models proposed from the TEM data. The oxidation states of the Mn and Fe atoms are evaluated by means of EELS and Mössbauer spectroscopy, which also reveals the different magnetic behavior of these oxides.