Disentangling Photodoping, Photoconductivity, and Photosuperconductivity in the Cuprates.

The normal-state conductivity and superconducting critical temperature of oxygen-deficient YBa_{2}Cu_{3}O_{7-δ} can be persistently enhanced by illumination. Strongly debated for years, the origin of those effects-termed persistent photoconductivity and photosuperconductivity (PPS)-has remained an unsolved critical problem, whose comprehension may provide key insights to harness the origin of high-temperature superconductivity itself. Here, we make essential steps toward understanding PPS. While the models proposed so far assume that it is caused by a carrier-density increase (photodoping) observed concomitantly, our experiments contradict such conventional belief: we demonstrate that it is instead linked to a photo-induced decrease of the electronic scattering rate. Furthermore, we find that the latter effect and photodoping are completely disconnected and originate from different microscopic mechanisms, since they present different wavelength and oxygen-content dependences as well as strikingly different relaxation dynamics. Besides helping disentangle photodoping, persistent photoconductivity, and PPS, our results provide new evidence for the intimate relation between critical temperature and scattering rate, a key ingredient in modern theories on high-temperature superconductivity.

Management of incidental durotomies in an integrated Orthopaedic and Neurosurgical Spinal Unit.

Introduction: Incidental durotomy (ID) is an intraoperative event associated to prolonged bed rest and hospital stay, antibiotic use, higher patient dissatisfaction, and leg pain among other complications of its postoperative course. Several repair techniques and postsurgical care have been proposed for its management. This study was designed to develop an agreed protocol in cases of ID among Orthopaedic Surgeons (OS) and Neurosurgeons (NS) integrated into a Spinal Surgery Unit. Research question: Incidental durotomies management protocol. Materials and methods: From 997 eligible cases operated in Hospital del Mar (Barcelona, Spain) from April 2018 to March 2022, demographic, clinical, surgical and postoperative data was collected for statistical analysis from the morbidity and mortality database, with 79 identified IDs. Redo procedures were significantly associated to OS, and cervical and anterior/lateral approaches to NS, both groups were not comparable. Results: ID occurred in 7.9% of cases, more frequently after the lockdown (p=0.03), in females (p=0.04), during posterior approaches (p=0.003), and less frequently in the cervical spine (p=0.009). IDs were linked to postoperative infections (p< 0.001) and nerve root damage (p< 0.001). Patients without ID evolved more satisfactorily during the postoperative period (p=0.002), and those with CSF leak (20/79) spent on bed rest more than twice the time as those without (p<0.001). Multivariable logistic regression showed strong association between posterior approaches and ID, between complicated postoperative courses and ID. Discussion and conclusions: ID is linked to an adverse postoperative recovery, and it should be primarily repaired under microscope, with early mobilization of patients after surgery.

Extremely long-range, high-temperature Josephson coupling across a half-metallic ferromagnet.

The Josephson effect results from the coupling of two superconductors across a spacer such as an insulator, a normal metal or a ferromagnet to yield a phase coherent quantum state. However, in junctions with ferromagnetic spacers, very long-range Josephson effects have remained elusive. Here we demonstrate extremely long-range (micrometric) high-temperature (tens of kelvins) Josephson coupling across the half-metallic manganite La0.7Sr0.3MnO3 combined with the superconducting cuprate YBa2Cu3O7. These planar junctions, in addition to large critical currents, display the hallmarks of Josephson physics, such as critical current oscillations driven by magnetic flux quantization and quantum phase locking effects under microwave excitation (Shapiro steps). The latter display an anomalous doubling of the Josephson frequency predicted by several theories. In addition to its fundamental interest, the marriage between high-temperature, dissipationless quantum coherent transport and full spin polarization brings opportunities for the practical realization of superconducting spintronics, and opens new perspectives for quantum computing.

Superconducting imprint of magnetic textures in ferromagnets with perpendicular magnetic anisotropy.

Research on proximity effects in superconductor/ferromagnetic hybrids has most often focused on how superconducting properties are affected-and can be controlled-by the effects of the ferromagnet's exchange or magnetic fringe fields. The opposite, namely the possibility to craft, tailor and stabilize the magnetic texture in a ferromagnet by exploiting superconducting effects, has been more seldom explored. Here we show that the magnetic flux trapped in high-temperature superconducting YBa2Cu3O7-δ microstructures can be used to modify the magnetic reversal of a hard ferromagnet-a cobalt/platinum multilayer with perpendicular magnetic anisotropy-and to imprint unusual magnetic domain distributions in a controlled manner via the magnetic field history. The domain distributions imprinted in the superconducting state remain stable, in absence of an external magnetic field, even after increasing the temperature well above the superconducting critical temperature, at variance to what has been observed for soft ferromagnets with in-plane magnetic anisotropy. This opens the possibility of having non-trivial magnetic configuration textures at room temperature after being tailored below the superconducting transition temperature. The observed effects are well explained by micromagnetic simulations that demonstrate the role played by the magnetic field from the superconductor on the nucleation, propagation, and stabilization of magnetic domains.

Large intrinsic anomalous Hall effect in SrIrO3 induced by magnetic proximity effect.

The anomalous Hall effect (AHE) is an intriguing transport phenomenon occurring typically in ferromagnets as a consequence of broken time reversal symmetry and spin-orbit interaction. It can be caused by two microscopically distinct mechanisms, namely, by skew or side-jump scattering due to chiral features of the disorder scattering, or by an intrinsic contribution directly linked to the topological properties of the Bloch states. Here we show that the AHE can be artificially engineered in materials in which it is originally absent by combining the effects of symmetry breaking, spin orbit interaction and proximity-induced magnetism. In particular, we find a strikingly large AHE that emerges at the interface between a ferromagnetic manganite (La0.7Sr0.3MnO3) and a semimetallic iridate (SrIrO3). It is intrinsic and originates in the proximity-induced magnetism present in the narrow bands of strong spin-orbit coupling material SrIrO3, which yields values of anomalous Hall conductivity and Hall angle as high as those observed in bulk transition-metal ferromagnets. These results demonstrate the interplay between correlated electron physics and topological phenomena at interfaces between 3d ferromagnets and strong spin-orbit coupling 5d oxides and trace an exciting path towards future topological spintronics at oxide interfaces.

Controlled Sign Reversal of Electroresistance in Oxide Tunnel Junctions by Electrochemical-Ferroelectric Coupling.

The persistence of ferroelectricity in ultrathin layers relies critically on screening or compensation of polarization charges which otherwise destabilize the ferroelectric state. At surfaces, charged defects play a crucial role in the screening mechanism triggering novel mixed electrochemical-ferroelectric states. At interfaces, however, the coupling between ferroelectric and electrochemical states has remained unexplored. Here, we make use of the dynamic formation of the oxygen vacancy profile in the nanometer-thick barrier of a ferroelectric tunnel junction to demonstrate the interplay between electrochemical and ferroelectric degrees of freedom at an oxide interface. We fabricate ferroelectric tunnel junctions with a La_{0.7}Sr_{0.3}MnO_{3} bottom electrode and BaTiO_{3} ferroelectric barrier. We use poling strategies to promote the generation and transport of oxygen vacancies at the metallic top electrode. Generated oxygen vacancies control the stability of the ferroelectric polarization and modify its coercive fields. The ferroelectric polarization, in turn, controls the ionization of oxygen vacancies well above the limits of thermodynamic equilibrium, triggering the build up of a Schottky barrier at the interface which can be turned on and off with ferroelectric switching. This interplay between electronic and electrochemical degrees of freedom yields very large values of the electroresistance (more than 10^{6}% at low temperatures) and enables a controlled switching between clockwise and counterclockwise switching modes in the same junction (and consequently, a change of the sign of the electroresistance). The strong coupling found between electrochemical and electronic degrees of freedom sheds light on the growing debate between resistive and ferroelectric switching in ferroelectric tunnel junctions, and moreover, can be the source of novel concepts in memory devices and neuromorphic computing.

Cognitive, motor, behavioural and academic performances of children born preterm: a meta-analysis and systematic review involving 64 061 children.

BACKGROUND: Preterm birth may leave the brain vulnerable to dysfunction. Knowledge of future neurodevelopmental delay in children born with various degrees of prematurity is needed to inform practice and policy. OBJECTIVE: To quantify the long-term cognitive, motor, behavioural and academic performance of children born with different degrees of prematurity compared with term-born children. SEARCH STRATEGY: PubMed and Embase were searched from January 1980 to December 2016 without language restrictions. SELECTION CRITERIA: Observational studies that reported neurodevelopmental outcomes from 2 years of age in children born preterm compared with a term-born cohort. DATA COLLECTION AND ANALYSIS: We pooled individual estimates of standardised mean differences (SMD) and odds ratios (OR) with 95% confidence intervals using a random effects model. MAIN RESULTS: We included 74 studies (64 061 children). Preterm children had lower cognitive scores for FSIQ (SMD: -0.70; 95% CI: -0.73 to -0.66), PIQ (SMD: -0.67; 95% CI: -0.73 to -0.60) and VIQ (SMD: -0.53; 95% CI: -0.60 to -0.47). Lower scores for preterm children in motor skills, behaviour, reading, mathematics and spelling were observed at primary school age, and this persisted to secondary school age, except for mathematics. Gestational age at birth accounted for 38-48% of the observed IQ variance. ADHD was diagnosed twice as often in preterm children (OR: 1.6; 95% CI: 1.3-1.8), with a differential effect observed according to the severity of prematurity (I2 = 49.4%, P = 0.03). CONCLUSIONS: Prematurity of any degree affects the cognitive performance of children born preterm. The poor neurodevelopment persists at various ages of follow up. Parents, educators, healthcare professionals and policy makers need to take into account the additional academic, emotional and behavioural needs of these children. TWEETABLE ABSTRACT: Adverse effect of preterm birth on a child's neurodevelopment persists up to adulthood.

Desarrollo y maduración normal de la médula ósea, valoración porresonancia magnética / Normal Development and Maturation of Bone Marrow Assessment by Magnetic Resonance Imaging

La maduración ósea ocurre de forma ordenada y predecible. Puede documentarse por medio de resonancia magnética incluso antes de que ocurran cambios histológicos, por lo cual es importante su adecuado conocimiento y caracterización.

Skeletal maturation occurs in an orderly and predictable manner. It can be documented by Magnetic Resonance Imaging even before histological changes occurs, so the importance of adequate knowledge and characterization must be stated.

Heat transport through lattices of quantum harmonic oscillators in arbitrary dimensions.

In d-dimensional lattices of coupled quantum harmonic oscillators, we analyze the heat current caused by two thermal baths of different temperatures, which are coupled to opposite ends of the lattice, with a focus on the validity of Fourier's law of heat conduction. We provide analytical solutions of the heat current through the quantum system in the nonequilibrium steady state using the rotating-wave approximation and bath interactions described by a master equation of Lindblad form. The influence of local dephasing in the transition of ballistic to diffusive transport is investigated.

Tiempo de transito colonico con marcadores radiopacos serie de casos / Colonic transit time with radiopaque markers: case studies

El tiempo de tránsito colónico con marcadores radiopacos (TTCMRO) es un estudio que constituye una manera sencilla y efectiva de evaluar la motilidad del colon. Fue descrito en 1969 y sigue vigente como un método complementario de estudio en pacientes con estreñimiento. Se presentan nueve casos de pacientes en quienes se realizó este estudio como parte del diagnóstico clínico de estreñimiento en 2010; se revisan así mismo la técnica, el aporte diagnóstico y las indicaciones del examen. Aunque en la literatura no hay una estandarización satisfactoria de la técnica de examen, el aporte del estudio para determinar el papel del colon en el estreñimiento de cada paciente ha hecho que se incluya en las guías de trabajo de estreñimiento, lo cual hace aún más relevante la importancia de estandarizar la técnica y la presentación del estúdio.

Diagnóstico por escanografía de bronquiolitis constructiva postinfecciosa(Síndrome de Swyer-James) en un paciente con distribución atípica de edema pulmonar de las alturas / Diagnosis by CT-Scan of Swyer-James syndrome in patient with atypical distribution of high altitud pulmonary edema

Presentamos el caso de un paciente quien ingresa con un edema pulmonar de las alturas, de distribución atípica, en quien se demuestran cambios escanográficos de Síndrome de Swyer-James.

Characterization of dehydrodolichyl diphosphate synthase of Arabidopsis thaliana, a key enzyme in dolichol biosynthesis.

The enzyme dehydrodolichyl diphosphate (dedol-PP) synthase is a cis-prenyltransferase that catalyzes the synthesis of dedol-PP, the long-chain polyprenyl diphosphate used as a precursor for the synthesis of dolichyl phosphate. Here we report the cloning and characterization of a cDNA from Arabidopsis thaliana encoding dedol-PP synthase. The identity of the cloned enzyme was confirmed by functional complementation of a yeast mutant strain defective in dedol-PP synthase activity together with the detection of high levels of dedol-PP synthase activity in the transformed yeast mutant. The A. thaliana dedol-PP synthase mRNA was detected at high levels in roots but was hardly detected in flowers, leaves, stems and in A. thaliana suspension-cultured cells.

Complicaciones sépticas de pared abdominal en cirugía limpia contaminada / Septic complications of contaminated abdominal wall surgery

Aún hoy en dia es contraversial el uso profiláctico en cirugía limpia contaminada (vesícula y vías biliares). Por tal motivo el objeto del presente trabajo es determinar el germén etiológico mas frecuente, semiología clínica y frecuencia de presentación, efectos de procedimientos quirúrgicos agregados y tiempo operatorio. A través de un estudio retrospectivo clínico controlado simple se estudio a los pacientes en el Hospital Clínico Viedma, por tatología de vesículas y de vías biliares, que resibieron profilaxis antibiótica. De 95 pacientes estudiados 7 presentaron infección de la herida operatoria, con un 7.3 por ciento de frecuencia. Se puede concluir que el uso profiláctico de antibióticos no disminuye en frecuencia la infección de pared. El germen habitual de vesícula y vías biliares es encontrado en el cultivo de secreción de pared abdominal y los procedimientos agregados a cirugía de vesícula y vía biliar son factores que aumentan el riesgo de infecciónb.

[Hereditary hemorrhagic telangiectasia as a cause of iron-deficiency anemia]. / Telangiectasia hemorrágica hereditaria como causa de anemia ferropénica.

We reviewed cases with Rendu-Osler disease or hereditary hemorrhagic telangiectasia (HHT) between 1976 and 1989 in our area of internal medicine. Of the ten reported cases, six presented severe iron deficiency anemia-three as a result of repeated and intense epistaxis and the rest as a result of digestive losses. The most frequent clinical manifestations were: epistaxis (80%) and the presence of characteristic mucocutaneous lesions easily explored by sight (80%). We emphasize the role of this disease as a cause of iron deficiency anemia and the importance of clinical exploration.