On-Demand Chemomagnetic Modulation of Striatal Neurons Facilitated by Hybrid Magnetic Nanoparticles.

Minimally invasive manipulation of cell signaling is critical in basic neuroscience research and in developing therapies for neurological disorders. Here, we describe a wireless chemomagnetic neuromodulation platform for the on-demand control of primary striatal neurons that relies on nanoscale heating events. Iron oxide magnetic nanoparticles (MNPs) are functionally coated with thermoresponsive poly (oligo (ethylene glycol) methyl ether methacrylate) (POEGMA) brushes loaded with dopamine. Dopamine loaded MNPs-POEGMA are co-cultured with primary striatal neurons. When alternating magnetinec fields (AMF) are applied, MNPs undergo hysteresis power loss and dissipate heat. The local heat produced by MNPs initiates a thermodynamic phase transition on POEGMA brushes resulting in polymer collapse and dopamine release. AMF-triggered dopamine release enhances the response of dopamine ion channels expressed on the cell membranes enhancing the activity of ~50% of striatal neurons subjected to the treatment. Chemomagnetic actuation on dopamine receptors is confirmed by blocking D1 and D2 receptors. The reversible thermodynamic phase transition of POEGMA brushes allow the on-demand release of dopamine in multiple microdoses. AMF-triggered dopamine release from MNPs-POEGMA causes no cell cytotoxicity nor promotes cell ROS production. This research represents a fundamental step forward for the chemomagnetic control of neural activity using hybrid magnetic nanomaterials with tailored physical properties.

Divergent copper-catalyzed syntheses of 3-carboxylpyrroles and 3-cyanofurans from O-acetyl oximes and ß-ketoesters/nitriles.

The reaction between O-acetyl oximes and ß-ketoesters/nitriles catalyzed by copper generated polysubstituted pyrroles and furans, respectively, under redox-neutral reaction conditions. Using this protocol, pyrroles or furans could be obtained simply by choosing an appropriate active methylene compound. Although both transformations occur essentially under the same reaction conditions, control experiments indicated that they follow different mechanistic pathways.

Comparative Study on the Quality of Microcrystalline and Epitaxial Silicon Films Produced by PECVD Using Identical SiF4 Based Process Conditions.

Hydrogenated microcrystalline silicon (µc-Si:H) and epitaxial silicon (epi-Si) films have been produced from SiF4, H2 and Ar mixtures by plasma enhanced chemical vapor deposition (PECVD) at 200 °C. Here, both films were produced using identical deposition conditions, to determine if the conditions for producing µc-Si with the largest crystalline fraction (XC), will also result in epi-Si films that encompass the best quality and largest crystalline silicon (c-Si) fraction. Both characteristics are of importance for the development of thin film transistors (TFTs), thin film solar cells and novel 3D devices since epi-Si films can be grown or etched in a selective manner. Therefore, we have distinguished that the H2/SiF4 ratio affects the XC of µc-Si, the c-Si fraction in epi-Si films, and the structure of the epi-Si/c-Si interface. Raman and UV-Vis ellipsometry were used to evaluate the crystalline volume fraction (Xc) and composition of the deposited layers, while the structure of the films were inspected by high resolution transmission electron microscopy (HRTEM). Notably, the conditions for producing µc-Si with the largest XC are different in comparison to the fabrication conditions of epi-Si films with the best quality and largest c-Si fraction.

Complications of Renal Transplantation That Influence the Presence of Hyperuricemia in Its First Year of Evolution.

INTRODUCTION: Renal transplantation (RT) has evolved to improve its functionality. Some factors have been little studied, one of which is hyperuricemia and its impact on renal graft function. The objective of this study is to determine the prevalence of complications of renal transplantation and its influence on hyperuricemia values in the first year of evolution. MATERIAL AND METHODS: The authors completed a retrospective, observational study of 2 RT units in Mexico from January 2013 to December 2017. In total, 1009 files met the inclusion criteria; the levels of uric acid (UA) and creatinine (Cr) were determined before transplantation and in months 1, 3, 6, 9, and 12 after transplantation. Descriptive analysis was performed with measures of central tendency, measures of dispersion, difference of means with Student t test, and SPSS version 25 (IBM, Armonk, NY, United States). RESULTS: The mean pretransplant UA was 6.24 mg/dL (standard deviation [SD] 1.97); per month was 4.73 mg/dL (SD 1.49). There is a difference in means between categorized groups of UA in the 5 post-RT moments (1, 3, 6, 9, and 12 months). A positive correlation of 0.41 to 0.47 was found with Spearman's test. The delayed function of the graft influenced in the first month after transplant in presenting hyperuricemia and acute dysfunction in month 6 showed that the rejection had no significance at any time. CONCLUSIONS: The relationship between the values of UA and Cr in the RT represents a moderate positive correlation; delayed graft function in the first month impacts the presence of hyperuricemia, as well as acute dysfunction at month 6 after transplantation.

Radicular symptoms associated with extrapedicular screw placement / Sintomas radiculares associados com a colocação extrapedicular de parafusos / Síntomas radiculares asociados a la colocación de tornillos extrapediculares

ABSTRACT: Objective: Transpedicular fixation has rapidly evolved over the last 100 years. A common complication is screw misplacement which can lead to neurological deficits, vascular damage, or organ perforation. We intend to assess the correlation between screw misplacement and radicular symptoms through the Gertzbein scale. Methods: We conducted an observational longitudinal retrospective study on patients who underwent free-hand lumbar instrumentation surgery with fluoroscopy assistance. The patients were evaluated with postoperative CT scans, and screw positions were classified with the Gertzbein scale. Results: The initial sample included 99 patients who underwent surgery. Of the 317 screws placed, 201 did not show cortical damage, 105 screws exhibited variable invasion, and 11 screws displayed severe invasion. 96.5% screws were placed in the safe zone, with 8.6% of patients (n=5.0) exhibiting transitory weakness. 3.47% of screws (n=11) with severe invasion were seen in 7 patients of which two patients suffered from motor deficient and persistent radicular pain. Conclusion: It is of the utmost importance to pay attention to the precise insertion of the screws to minimize the risk of radicular manifestations. We recommend performing control CT scans after the procedure to ensure the correct insertion of the screws, and in case of finding a screw in a no-safe zone or Getsbein 3 position, considering screw repositioning due to high-risk neurologic damage is highly encouraged. Level of Evidence II; Observational Retrospective Study.

RESUMO: Objetivo: A fixação transpedicular evoluiu rapidamente nos últimos 100 anos, porém o deslocamento do parafuso é uma complicação comum que pode resultar em déficits neurológicos ou danos vasculares. Pretendemos correlacionar o deslocamento do parafuso com sintomas radiculares usando a escala de Gertzbein. Métodos: Conduzimos um estudo retrospectivo longitudinal observacional em pacientes submetidos à cirurgia de instrumentação lombar à mão livre com assistência de fluoroscopia. Os pacientes foram avaliados com tomografia computadorizada pós-operatória e as posições dos parafusos foram classificadas com a escala de Gertzbein. Resultados: A amostra inicial incluiu 99 pacientes. Dos 317 parafusos colocados, 201 não mostraram danos corticais, 105 exibiram invasão variável e 11 invasão severa. 96,5% dos parafusos foram colocados na zona segura, com 8,6% dos pacientes apresentando fraqueza transitório. 3,47% dos parafusos com invasão severa foram observados em 7 pacientes, dos quais 2 sofreram de deficiência motora e dor radicular persistente. Conclusão: É crucial prestar atenção à inserção precisa dos parafusos para minimizar o risco de manifestações radiculares. Recomendamos tomografias de controle para garantir a correta inserção dos parafusos e, se necessário, reposicionamento devido ao alto risco de dano neurológico. Nível de Evidência II; Estudo Observacional Retrospectivo.

RESUMEN: Objetivo: La fijación transpedicular ha evolucionado en los últimos 100 años. Una complicación común es el desplazamiento de tornillos, causante de déficits neurológicos o daños vasculares. Buscamos correlacionar el desplazamiento con síntomas radiculares mediante la escala de Gertzbein. Métodos: Se realizó un estudio observacional longitudinal retrospectivo de pacientes sometidos a cirugía de instrumentación lumbar a mano alzada asistida por fluoroscopia. Los pacientes fueron evaluados con tomografía computarizada postoperatoria y las posiciones de los tornillos se clasificaron con la escala de Gertzbein. Resultados: La muestra inicial incluyó 99 pacientes. De los 317 tornillos colocados, 201 no mostraron daño cortical, 105 mostraron invasión variable y 11 mostraron invasión severa. El 96,5% de los tornillos se colocaron en la zona segura, y el 8,6% de los pacientes mostraron debilidad transitoria. Se observó un 3,47% de tornillos con invasión grave en 7 pacientes, 2 de los cuales sufrieron discapacidad motora y dolor radicular persistente. Conclusión: Es crucial prestar atención a la inserción precisa de los tornillos para minimizar el riesgo de manifestaciones radiculares. Recomendamos la realización de tomografias de control para asegurar la correcta inserción de los tornillos y, en caso necesario, su recolocación debido al elevado riesgo de daño neurológico. Nivel de Evidencia II; Estudio Observacional Retrospectivo.