Nuestra Experiencia en el Estudio con Ultrasonografía en la Cadera Neonatal

Se estudian mediante ultrasonografía las caderas de 112 recién nacidos (224 caderas) con signos clínicos de displasia luxante de cadera. Los resultados se comparan con los datos de exploración clínica y estudio radiográ- fico poniendo en evidencia las limitaciones diagnósticas de las maniobras exploratorias clásicas y la radiografía. Concluye que la ultrasonografía es el método más seguro e inocuo para el diagnóstico precoz de la displasia luxante de cadera en el recién nacido.The authors are studied by ultrasonography 112 newborns (224 hips) with clinical signs of congenital dysplasia and dislocation of the hip. The results obtained are compared with clinical findings and radiographic study emphasizing the diagnostic limitations of the clasics maneuvistes of physical examination and radiography. They conclude that the ultrasonography is the most sure method and innocuous to the early diagnosis of the congenital dysplasia and dislocation of the hip at the newborn

Los Ultrasonidos en la Cadera Neonatal

Los autores describen la técnica de Estudio mediante Ecografía de la cadera neonatal, las imágenes normales, los métodos de mediciones y las características de los distintos grados de displasiaThe authors describe the technique of the study by ultrasound examination of neonatal hip, normal images, methods of measurement and characteristics of differents degrees of dysplasi

Scanning tunneling spectroscopy of layers of superconducting 2H-TaSe2_\textbf{2}: Evidence for a zero bias anomaly in single layers

We report a characterization of surfaces of the dichalcogenide TaSe$_2$ using scanning tunneling microscopy and spectroscopy (STM/S) at 150 mK. When the top layer has the 2H structure and the layer immediately below the 1T structure, we find a singular spatial dependence of the tunneling conductance below 1 K, changing from a zero bias peak on top of Se atoms to a gap in between Se atoms. The zero bias peak is additionally modulated by the commensurate $3a_0 \times 3a_0$ charge density wave of 2H-TaSe$_2$. Multilayers of 2H-TaSe$_2$ show a spatially homogeneous superconducting gap with a critical temperature also of 1 K. We discuss possible origins for the peculiar tunneling conductance in single layers.Comment: 10 pages, 10 figure

Fault-tolerant strategies in MMC-based high power magnet supply for particle accelerator

Many particle accelerators require to supply chains of magnets with high quality, high magnitude, cycling currents. To do this, the power converters need to provide high output voltages, reaching in some cases tens of kilovolts. Additionally, converters are required to store the magnet energy during de-magnetization cycles. For such application, Full-bridge Modular Multilevel Converters (FB-MMC) could be used given their capacity to store energy and their inherent reliability. In this sense, one of the most interesting features of the proposed topology is the possibility of bypassing one or several submodules in the event of a fault or malfunction. By doing this, it is possible to ride-through the failure of a component and avoid the interruption of the accelerator operation. However, when the number of submodules is small, this operation could lead to an excessive charge of the healthy cells, increasing the risk of secondary failures. Besides, undesired harmonic content could appear on the output current, degrading the operation of the accelerator. It is then necessary to implement strategies that allow to remove a faulty cell without significantly impacting the operation of the remaining ones and of the converter itself. Accordingly, the purpose of this article is to investigate several of these strategies and assess them. By means of detailed computer simulations, the behaviour of the converter during normal and submodule fault conditions is analysed. Then, several fault-tolerant strategies are described, verified and compared with the aid of simulation tools. The results show the effectiveness of the analysed strategies in avoiding the overvoltage on the healthy submodules after a cell bypass and the little impact of this operation on the quality of the converter output current

Fault-tolerant strategies in MMC-based high power magnet supply for particle accelerator

[EN] Many particle accelerators require to supply chains of magnets with high quality, high magnitude, cycling currents. To do this, the power converters need to provide high output voltages, reaching in some cases tens of kilovolts. Additionally, converters are required to store the magnet energy during de-magnetization cycles. For such application, Full-bridge Modular Multilevel Converters (FB-MMC) could be used given their capacity to store energy and their inherent reliability. In this sense, one of the most interesting features of the proposed topology is the possibility of bypassing one or several submodules in the event of a fault or malfunction. By doing this, it is possible to ride-through the failure of a component and avoid the interruption of the accelerator operation. However, when the number of submodules is small, this operation could lead to an excessive charge of the healthy cells, increasing the risk of secondary failures. Besides, undesired harmonic content could appear on the output current, degrading the operation of the accelerator. It is then necessary to implement strategies that allow to remove a faulty cell without significantly impacting the operation of the remaining ones and of the converter itself. Accordingly, the purpose of this article is to investigate several of these strategies and assess them. By means of detailed computer simulations, the behaviour of the converter during normal and submodule fault conditions is analysed. Then, several fault-tolerant strategies are described, verified and compared with the aid of simulation tools. The results show the effectiveness of the analysed strategies in avoiding the overvoltage on the healthy submodules after a cell bypass and the little impact of this operation on the quality of the converter output current.Colmenero Moratalla, M.; Vidal-Albalate, R.; Blanquez Delgado, FR.; Blasco-Gimenez, R. (2023). Fault-tolerant strategies in MMC-based high power magnet supply for particle accelerator. Mathematics and Computers in Simulation. 1-17. https://doi.org/10.1016/j.matcom.2023.07.01411

Strong enhancement of superconductivity at high pressures within the charge-density-wave states of 2H-TaS 2 and 2H-TaSe 2

We present measurements of the superconducting and charge density wave critical temperatures (Tc and TCDW) as a function of pressure in the transition metal dichalchogenides 2H-TaSe2 and 2H-TaS2. Resistance and susceptibility measurements show that Tc increases from temperatures below 1 K up to 8.5 K at 9.5 GPa in 2H-TaS2 and 8.2 K at 23 GPa in 2H-TaSe2. We observe a kink in the pressure dependence of TCDW at about 4 GPa that we attribute to the lock-in transition from incommensurate CDW to commensurate CDW. Above this pressure, the commensurate TCDW slowly decreases coexisting with superconductivity within our full pressure range.Comment: Published in Phys. Rev B 93, 184512 (2016

Electrical Control of 2D Magnetism in Bilayer CrI3

The challenge of controlling magnetism using electric fields raises fundamental questions and addresses technological needs such as low-dissipation magnetic memory. The recently reported two-dimensional (2D) magnets provide a new system for studying this problem owing to their unique magnetic properties. For instance, bilayer chromium triiodide (CrI3) behaves as a layered antiferromagnet with a magnetic field-driven metamagnetic transition. Here, we demonstrate electrostatic gate control of magnetism in CrI3 bilayers, probed by magneto-optical Kerr effect (MOKE) microscopy. At fixed magnetic fields near the metamagnetic transition, we realize voltage-controlled switching between antiferromagnetic and ferromagnetic states. At zero magnetic field, we demonstrate a time-reversal pair of layered antiferromagnetic states which exhibit spin-layer locking, leading to a remarkable linear dependence of their MOKE signals on gate voltage with opposite slopes. Our results pave the way for exploring new magnetoelectric phenomena and van der Waals spintronics based on 2D materials.Comment: To appear in Nature Nanotechnolog

A collection of three integration-free iPSCs derived from old male and female healthy subjects

Here, we present the characterization of three iPSC lines derived from dermal fibroblasts of old healthy subjects. Fibroblasts were reprogrammed using Sendai viral vectors encoding OCT4, SOX2, KLF4 and c-MYC. The iPSCs expressed endogenous pluripotency markers, could generate the three germ layers (ectoderm, mesoderm and endoderm), maintained a stable karyotype, and were free from Sendai vectors and reprogramming factors. These integration-free iPSCs can serve for establishing control cell cultures in studies searching for phenotypes and mechanisms that could potentially be dysregulated in degenerative diseases

Sex-specific behavioral and neurogenic responses to cocaine in mice lacking and blocking dopamine D1 or dopamine D2 receptors

Adult neurogenesis in rodents is modulated by dopaminergic signaling and inhibited by cocaine. However, the sex-specific role of dopamine D1 and D2 receptors (D1R, D2R) in the deleterious effect of cocaine on adult neurogenesis has not been described yet. Here, we explored sex differences in (a) cell proliferation (5′-bromo-2′-deoxyuridine [BrdU]), (b) neural precursor (nestin), (c) neuronal phenotype (BrdU/β3-tubulin), and (d) neuronal maturity (NeuN) in the subventricular zone (SVZ) of the lateral ventricles and striatum of mice with genetic deletion (D1, D2) or pharmacological blockage (SCH23390: 0.1 mg/kg/day/5 days; Raclopride: 0.3 mg/kg/day/5 days) of D1R and D2R, and treated (10 mg/kg/day/5 days) and then challenged (5 mg/kg, 48 hr later) with cocaine. Results indicated that hyperactivity responses to cocaine were absent in D1 mice and reduced in SCH23390-treated mice. Activity responses to cocaine were reduced in D2 males, but absent in D2 females and increased in Raclopride-treated females. D1R deletion blocked the deleterious effect of cocaine on SVZ cell proliferation in males. Cocaine-exposed D1 males also had reduced neuronal phenotype of SVZ newborn cells and increased striatal neuronal maturity. D2 mice had lower proliferative and neural precursor responses. Cocaine in D2 females or coadministered with Raclopride in wild-type females improved SVZ cell proliferation, an effect that positively correlated with plasma brain-derived neurotrophic factor (BDNF) concentrations. In conclusion, the sex-specific D1R and D2R signaling on SVZ cell proliferation, neural progenitor and neuronal maturity is differentially perturbed by cocaine, and BDNF may be required to link D2R to neuroplasticity in cocaine addiction in females.Consejería de Salud, Junta de Andalucía, Grant/Award Number: C1-0049-2019; Instituto de Salud Carlos III, Grant/Award Numbers: CP19/00068, CPII17/00024, CPII19/00022, CPII19/00031, PI19/01577, PI19/00886, PI17/02026, RD16/0017/0001; Ministerio de Sanidad, Servicios Sociales e Igualdad, Grant/Award Numbers: PND2017/043, PND2018/033, PND2018/044, PND2019/04