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.

Coinfección por COVID-19 y gripe A: una cuestión de principios / COVID-19 and influenza A coinfection: a matter of principle

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Modified Synthesis Strategies for the Stabilization of low n Tin O2n-1 Magnéli Phases.

Titanium reduced oxides TiO2-x occupy, since long time, a prominent place on the landscape of binary metal oxides because of their intriguing ability to form extended defects that affect both the formation of new superlattices and different electronic behaviours. Related to these features, a wide range of practical applications has been achieved. Moved by the conviction of the great potential of understanding the influence of the reactivity, compositional variations and size effects on their functional properties, the aim of this personal account is the optimization of a recently developed strategy for the stabilization of low n Tin O2n-1 terms. In particular, we will focus on the Ti4 O7 composition as well as the incorporation of transition metals, like Mn, in order to deal with new reduced Magnéli phases.

Atomically Resolved Short-Range Order at the Nanoscale in the Ca-Mn-O System.

The elucidation of the reaction mechanisms involving redox processes in functional transition-metal oxides, which usually start in areas of very few nanometers in size, is yet a challenge to be satisfactorily achieved. Atomically resolved HAADF and EELS have provided both chemical and structural information at the nanoscale, which reveal the preservation of short-range cationic order in areas of 2-3 nm length as the driving force behind the reversibility of the Ca2Mn3O8-Ca2Mn3O5 redox process. Oxygen evolution is accommodated by cationic diffusion along the Ca and Mn layers of the cation-deficient Ca2Mn3O8 delafossite related structure, whereas Mn remains octahedrally coordinated.

Presynaptic GABAB Receptors Regulate Hippocampal Synapses during Associative Learning in Behaving Mice.

GABAB receptors are the G-protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the central nervous system. Pharmacological activation of GABAB receptors regulates neurotransmission and neuronal excitability at pre- and postsynaptic sites. Electrophysiological activation of GABAB receptors in brain slices generally requires strong stimulus intensities. This raises the question as to whether behavioral stimuli are strong enough to activate GABAB receptors. Here we show that GABAB1a-/- mice, which constitutively lack presynaptic GABAB receptors at glutamatergic synapses, are impaired in their ability to acquire an operant learning task. In vivo recordings during the operant conditioning reveal a deficit in learning-dependent increases in synaptic strength at CA3-CA1 synapses. Moreover, GABAB1a-/- mice fail to synchronize neuronal activity in the CA1 area during the acquisition process. Our results support that activation of presynaptic hippocampal GABAB receptors is important for acquisition of a learning task and for learning-associated synaptic changes and network dynamics.

The GABAergic septohippocampal pathway is directly involved in internal processes related to operant reward learning.

We studied the role of γ-aminobutyric acid (GABA)ergic septohippocampal projections in medial septum (MS) self-stimulation of behaving mice. Self-stimulation was evoked in wild-type (WT) mice using instrumental conditioning procedures and in J20 mutant mice, a type of mouse with a significant deficit in GABAergic septohippocampal projections. J20 mice showed a significant modification in hippocampal activities, including a different response for input/output curves and the paired-pulse test, a larger long-term potentiation (LTP), and a delayed acquisition and lower performance in the MS self-stimulation task. LTP evoked at the CA3-CA1 synapse further decreased self-stimulation performance in J20, but not in WT, mice. MS self-stimulation evoked a decrease in the amplitude of field excitatory postsynaptic potentials (fEPSPs) at the CA3-CA1 synapse in WT, but not in J20, mice. This self-stimulation-dependent decrease in the amplitude of fEPSPs was also observed in the presence of another positive reinforcer (food collected during an operant task) and was canceled by the local administration of an antibody-inhibiting glutamate decarboxylase 65 (GAD65). LTP evoked in the GAD65Ab-treated group was also larger than in controls. The hippocampus has a different susceptibility to septal GABAergic inputs depending on ongoing cognitive processes, and the GABAergic septohippocampal pathway is involved in consummatory processes related to operant rewards.

Retrospective study assesing the role of MRI in the diagnostic procedures for early breast carcinoma: a correlation of new foci in the MRI with tumor pathological features

BACKGROUND: Use of breast magnetic resonance imaging (MRI) to detect breast cancer has generated significant debate. We analyze the role of breast MRI in the detection of additional disease and the need to perform additional biopsies in early breast carcinoma patients. In addition, we correlate the detection of new foci with tumor pathological features. METHODS: Early breast carcinoma patients that had undergone an MRI as well as a mammography as diagnostic procedures were included in the study. The following pathologic features were studied: carcinoma type, histological grade, estrogen receptors (ER), progesterone receptors (PR), HER2 and Ki67. Univariate analysis was conducted to ascertain significant correlation among detection of new foci and each of the tumor pathological features. RESULTS: Data from 98 patients have been analyzed: median age 49 years (range 35-79); carcinoma type: (a) infiltrative ductal carcinoma (n = 73, 74 %), (b) infiltrative lobular cancer (n = 12, 12 %), (c) ductal carcinoma in situ (n = 6, 6 %); amplified HER2 (n = 18, 18 %); grade III (n = 33, 33 %); Ki67 ≥ 25 % (n = 33, 33.67 %); positive ER and PR (n = 79, 80 %); triple negative tumors (n = 8, 8 %). MRI detected additional disease in 38 cases (39.58 %), and 20 led to an additional biopsy (20.4 %). Thirty-eight patients (39 %) underwent mastectomy. We found a statistically significant correlation between new foci in MRI and high Ki67 ≥ 25 % (p < 0.005). No other statistically significant correlation was established. CONCLUSION: MRI detected additional disease in 39 % cases, requiring an additional biopsy 20 %. Tumors with high proliferative index were significantly correlated with the detection of new foci in MRI (AU)

Differential contribution of hippocampal circuits to appetitive and consummatory behaviors during operant conditioning of behaving mice.

Operant conditioning is a type of associative learning involving different and complex sensorimotor and cognitive processes. Because the hippocampus has been related to some motor and cognitive functions involved in this type of learning (such as object recognition, spatial orientation, and associative learning tasks), we decided to study in behaving mice the putative changes in strength taking place at the hippocampal CA3-CA1 synapses during the acquisition and performance of an operant conditioning task. Mice were chronically implanted with stimulating electrodes in the Schaffer collaterals and with recording electrodes in the hippocampal CA1 area and trained to an operant task using a fixed-ratio (1:1) schedule. We recorded the field EPSPs (fEPSPs) evoked at the CA3-CA1 synapse during the performance of appetitive (going to the lever, lever press) and consummatory (going to the feeder, eating) behaviors. In addition, we recorded the local field potential activity of the CA1 area during similar behavioral displays. fEPSPs evoked at the CA3-CA1 synapse presented larger amplitudes for appetitive than for consummatory behaviors. This differential change in synaptic strength took place in relation to the learning process, depending mainly on the moment in which mice reached the selected criterion. Thus, selective changes in CA3-CA1 synaptic strength were dependent on both the behavior display and the learning stage. In addition, significant changes in theta band power peaks and their corresponding discrete frequencies were noticed during these behaviors across the sequence of events characterizing this type of associative learning but not during the acquisition process.

Retrospective study assessing the role of MRI in the diagnostic procedures for early breast carcinoma: a correlation of new foci in the MRI with tumor pathological features.

BACKGROUND: Use of breast magnetic resonance imaging (MRI) to detect breast cancer has generated significant debate. We analyze the role of breast MRI in the detection of additional disease and the need to perform additional biopsies in early breast carcinoma patients. In addition, we correlate the detection of new foci with tumor pathological features. METHODS: Early breast carcinoma patients that had undergone an MRI as well as a mammography as diagnostic procedures were included in the study. The following pathologic features were studied: carcinoma type, histological grade, estrogen receptors (ER), progesterone receptors (PR), HER2 and Ki67. Univariate analysis was conducted to ascertain significant correlation among detection of new foci and each of the tumor pathological features. RESULTS: Data from 98 patients have been analyzed: median age 49 years (range 35-79); carcinoma type: (a) infiltrative ductal carcinoma (n = 73, 74 %), (b) infiltrative lobular cancer (n = 12, 12 %), (c) ductal carcinoma in situ (n = 6, 6 %); amplified HER2 (n = 18, 18 %); grade III (n = 33, 33 %); Ki67 ≥ 25 % (n = 33, 33.67 %); positive ER and PR (n = 79, 80 %); triple negative tumors (n = 8, 8 %). MRI detected additional disease in 38 cases (39.58 %), and 20 led to an additional biopsy (20.4 %). Thirty-eight patients (39 %) underwent mastectomy. We found a statistically significant correlation between new foci in MRI and high Ki67 ≥ 25 % (p < 0.005). No other statistically significant correlation was established. CONCLUSION: MRI detected additional disease in 39 % cases, requiring an additional biopsy 20 %. Tumors with high proliferative index were significantly correlated with the detection of new foci in MRI.

Observational learning in mice can be prevented by medial prefrontal cortex stimulation and enhanced by nucleus accumbens stimulation.

The neural structures involved in ongoing appetitive and/or observational learning behaviors remain largely unknown. Operant conditioning and observational learning were evoked and recorded in a modified Skinner box provided with an on-line video recording system. Mice improved their acquisition of a simple operant conditioning task by observational learning. Electrical stimulation of the observer's medial prefrontal cortex (mPFC) at a key moment of the demonstration (when the demonstrator presses a lever in order to obtain a reward) cancels out the benefits of observation. In contrast, electrical stimulation of the observer's nucleus accumbens (NAc) enhances observational learning. Ongoing cognitive processes in the demonstrator could also be driven by electrical stimulation of these two structures, preventing the proper execution of the ongoing instrumental task (mPFC) or stopping pellet intake (NAc). Long-term potentiation (LTP) evoked in these two cortical structures did not prevent the acquisition or retrieval process--namely, mPFC and/or NAc stimulation only prevented, or modified, the ongoing behavioral process. The dorsal hippocampus was not involved in either of these two behavioral processes. Thus, both ongoing observational learning and performance of an instrumental task require the active contribution of the mPFC and/or the NAc.

Dolor abdominal autolimitado: diagnóstico por imagen / Self-limited abdominal pain: diagnostic imaging

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Cumplimiento, conocimiento y automedicación como factores asociados a los resultados clínicos negativos de la farmacoterapia / Therapy compliance, patient knowledge of medicines and self-medication as associated factors in negative clinical outcomes in pharmacotherapy

El paciente juega un papel primordial en la consecución de los resultados terapéuticos. El incumplimiento, la automedicación, o la falta de conocimiento del la farmacoterapia pueden ser causas de esos resultados clínicos negativos, denominados en ocasiones problemas relacionados con medicamentos (PRM). El método Dáder se utilizó para la evaluación, identificación y clasificación de PRM. La asociación de variables se estableció mediante el estadístico chi cuadrado. El conocimiento de la medicación, el cumplimiento y la automedicación fueron estudiados como causa de estos resultados negativos de la medicación. Fueron entrevistados 2556 pacientes durante el año de estudio, resultando 2261 casos válidos. El 33 % presentaron un PRM como causa de visita a urgencias. El conocimiento de la medicación, el cumplimiento y la automedicación fueron estudiados solo en la población que presentó un PRM y se demuestra que son aspectos asociados a las distintas dimensiones de PRM. No es posible establecer asociación entre la existencia o no de resultados clínicos negativos en los pacientes con el conocimiento de la medicación, el cumplimiento y la automedicación, debido a que estas variables no son atributos del paciente sino que están asociadas a cada medicamento

The patient plays a fundamental role in the attainment of good results in pharmacotherapy. Noncompliance, self-medication, or insufficient knowledge of the therapy being employed may provide a source for the causes of these negative clinical outcomes, otherwise known as medicine related problems (MRP). he Dader method was used in the evaluation, identification and classification of MRP. The association of variables was established through the statistical Chi square test. Patient knowledge of the medicine, degree of compliance to therapy and self-medication were studied as causes of the negative outcomes encountered. 2556 patients were interviewed throughout the year that the study took place, giving a total of 2261 of valid cases. 33% presented an MRP as the cause of his/her visit to the hospital emergency ward. Knowledge of the medicine, compliance and self-medication were only studied in the population that presented an MRP and in this work it is demonstrated that these are aspects that are associated with different dimensions of MRP. It is not possible to establish an association between the existence or not of negative clinical outcomes in patients with the factors of knowledge of medication, compliance and self-medication. This is due to the fact that these variables are not attributable to the patient himself, but rather are associated with the characteristics of each medicine

[Haemophagocytic syndrome and cutaneous T-cell lymphoma]. / Síndrome hemofagocítico y linfoma cutáneo de células T.

Haemophagocytic syndrome is a rare disorder of immune regulation. Clinical features are fever, haemophagocytosis, hepatosplenomegaly, pancytopenia, lymph nodes enlargement, hypertriglyceridaemia and coagulopathy. Systemic findings may also include pulmonary infiltrates, renal failure and an inappropriate antidiuretic state. It has been described associated to many diseases, like lymphomas, most of them T-cell lymphomas, infections and systemic diseases, among other entities. Haemopoietic cells are actively ingested by monocytes and macrophages in lymph nodes, bone marrow, liver and spleen. This is a diagnostic criteria for haemophagocytic syndrome. The treatment of haemophagocytic syndrome is difficult and requires intensive supportive therapy, treatment of coagulopathy disorders, high-dose corticosteroids and immunosuppressive treatment, although in most cases there is no response to treatment and the evolution is fatal. The T-cell lymphomas that involve subcutaneous tissue and simulate panniculitis are classified recently as primary cutaneous T-cell lymphomas, and their presentation as inflammatory nodules of the legs are uncommon.

Síndrome hemofagocítico y linfoma cutáneo de células T / Haemophagocytic syndrome and cutaneous t-cell lymphoma

El síndrome hemofagocítico (SHF) es un trastorno infrecuente de la inmunorregulación, cuyas manifestaciones clínicas son fiebre, hemofagocitosis, hepatoesplenomegalia, pancitopenia, linfadenopatías, hipertrigliceridemia y coagulopatía. Puede cursar también con afectación pulmonar, fracaso renal agudo o síndrome de secreción inadecuada de ADH (SIADH).Se ha descrito asociado a múltiples enfermedades, destacando los linfomas, sobre todo de células T, infecciones y enfermedades sistémicas, entre otras entidades. Las células hematopoyéticas son fagocitadas por monocitos y macrófagos en los ganglios linfáticos, médula ósea, hígado y bazo, lo que constituye un criterio diagnóstico del SHF. El tratamiento es difícil e incluye medidas de soporte y de las alteraciones de coagulación así como corticoides sistémicos a altas dosis e inmunosupresores, aunque en la mayoría de ocasiones no hay respuesta al tratamiento y la evolución es fatal. Los linfomas T que afectan al tejido celular subcutáneo y simulan una paniculitis han sido clasificados recientemente como linfomas cutáneos de células T (LCCT), siendo infrecuente su presentación como nódulos inflamatorios en extremidades inferiores (AU)

[Kikuchi's disease: a case report and literature review]. / Enfermedad de Kikuchi: a propósito de un caso y revisión de la literatura.

Kikuchi-Fujimoto disease, also known as hystiocytic necrotizing lymphadenitis, is an unusual entity which affects predominantely young Asiatic females, although its distribution is world-wide. Cardinal symptoms are fever and adenopathy, generally cervical, although generalized and extraganglionar cases have been described. Considered a self-limiting disease, it has to be differentiated by pathologic analysis from other less-benign disorders such as lymphoma or histiocytoma, which bear worse prognosis and may require specific treatment. Although the origin of this disease is unknown, a viral origin is postulated and the immune system is involved Kikuchi disease has been associated to other entities such as subcutaneous lupus erythematosus, Hashimoto thyroiditis, etc... requiring that patients be followed immunologically alter diagnosis of this disease. We present a case of Kikuchi disease associated with subacute lymphocytic thyroiditis.