Resultados funcionales de pacientes con menisco discoide intervenidos quirúrgicamente en una clínica de ortopedia infantil / Functional results of patients with discoid meniscus undergoing surgery in a children's orthopedics clinic

Introducción: El menisco discoide es una malformación del menisco que puede generar sintomatología en niños y adolescentes, se han desarrollado técnicas artroscópicas logrando mejorar la funcionalidad en la gran mayoría de pacientes con menisco discoide y lesiones asociadas. El objetivo es mostrar los resultados clínicos y funcionales de pacientes intervenidos por artroscopia en un centro de referencia en ortopedia infantil durante un periodo de 3 años. Materiales y métodos: Se analizaron los resultados de una cohorte retrospectiva de pacientes menores de 18 años intervenidos quirúrgicamente por menisco discoide sintomático en un período de 3 años, a través de revisión de historias clínicas, evaluando los resultados clínicos mediante la escala de Tegner-Lysholm. Resultados: Se intervinieron 25 rodillas en 21 pacientes con un promedio de edad de 8,9 años. El tiempo de seguimiento promedio fue de 8,3 meses, donde 60% de las rodillas tenía inestabilidad del anillo periférico. El 92% de los pacientes tuvo puntaje excelente (>90) en la escala Tegner-Lysholm y el 8% restante, un puntaje bueno. El 88% de los casos no presentaron dolor postoperatorio y el 12%, dolor leve. El regreso al deporte se dio en los primeros 4 meses en 19 pacientes. Conclusión: El tratamiento artroscópico del menisco discoide sintomático con remodelación meniscal y estabilización del anillo periférico tiene buenos resultados funcionales a corto y mediano plazo, permitiéndole a los pacientes retornar a sus actividades deportivas en un lapso corto de tiempo.

Introduction: The discoid meniscus is a malformation of the meniscus that can generate symptoms in children and adolescents. Arthroscopic techniques have been developed to improve functionality in the vast majority of patients with discoid meniscus and associated injuries. The objective is to show the clinical and functional results of patients undergoing arthroscopy in a reference center for children's orthopedics over a period of 3 years. Materials and methods: The results of a retrospective cohort of patients under 18 years of age who underwent surgery for symptomatic discoid meniscus in a period of 3 years were analyzed through a review of medical records, evaluating clinical results using the Tegner-Lysholm scale. . Results: 25 knees were operated on in 21 patients with an average age of 8.9 years. The average follow-up time was 8.3 months, where 60% of the knees had peripheral annulus instability. 92% of the patients had an excellent score (>90) on the Tegner-Lysholm scale and the remaining 8% had a good score. 88% of cases did not present postoperative pain and 12% had mild pain. Return to sport occurred in the first 4 months in 19 patients. Conclusion: Arthroscopic treatment of symptomatic discoid meniscus with meniscal remodeling and stabilization of the peripheral annulus has good functional results in the short and medium term, allowing patients to return to their sports activities in a short period of time.

Rattlesnake (Crotalus spp.) distribution and diversity in Zacatecas, Mexico.

Mexico is home to a large number of reptile species and has one of the greatest diversities of venomous snakes, among which the rattlesnakes pertaining to the Crotalus genus stand out. Out of more than 40 species in the country, nine are found in Zacatecas: C. aquilus, C. atrox, C. basiliscus, C. lepidus, C. molossus, C. polystictus, C. pricei, C. scutulatus and C. willardi. Although these reptiles are important, due to their relevance in terms of ecology, cultural use and public health, their conservation is impacted by multiple factors, such as habitat fragmentation and indiscriminate killing. Thus, most species within this genus are found in some type of risk category at both the national and international level. The purpose of this study was to determine the potential distribution and diversity of rattlesnakes at the municipal level in the understudied state of Zacatecas. To do this, we analyzed and described the global distribution of nine rattlesnake species by building species distribution models, which determined their potential distribution based on a set of ecological variables and presence records. The resulting models were used to assess the diversity of rattlesnake species potentially present in each municipality within the state. Thirty-nine (67.24 %) out of fifty-eight municipalities registered at least one rattlesnake species. Fresnillo, Sombrerete and Valparaíso were some of the municipalities showing greatest diversity. Moreover, C. atrox, C. lepidus, C. molossus and C. scutulatus were the most widely found species in the state. On the other hand, C. basiliscus, C. polystictus, C. pricei and C. willardi were rarely spotted and so, information on their distribution patterns within Zacatecas is limited. Finally, the areas having the largest potential for the distribution of these species were defined. These findings should make field work much more time- and cost-effective, facilitating the collection of in situ data that are useful for management and conservation plans of these species in Zacatecas.

Roturas masivas del manguito de los rotadores: resultados clínicos de la reparación artroscópica con técnica doble MAC / Massive rotator cuff tears: Clinical outcomes of arthroscopic repair using a double MAC technique

Introducción Las roturas masivas del manguito de los rotadores representan una de las lesiones más complejas a las cuales se puede enfrentar el ortopedista especialista en hombro y son un gran reto cuando se desean lograr resultados clínicos satisfactorios. El objetivo del trabajo es describir los resultados clínicos de una nueva técnica quirúrgica para la reparación artroscópica de lesiones grandes y masivas del manguito de los rotadores (MR) utilizada en una clínica ortopédica especializada durante un período de 3 años. Materiales y métodos Se realizó un estudio descriptivo de una cohorte de pacientes con lesiones grandes y masivas del MR, diagnosticados mediante artrorresonancia directa y que cumplían criterios para reparación artroscópica, a los cuales se les realizó la reparación mediante una nueva técnica denominada doble MAC. Se analizaron como desenlaces la escala de Constant postoperatoria, la existencia de complicaciones y el grado de satisfacción de los pacientes con el procedimiento. Resultados Se evaluó a 21 pacientes (10 hombres y 11 mujeres) con una media de edad de 59,4 años (DE: 8,2) en el momento de la cirugía. Las roturas comprometieron el músculo supraespinoso en todos los casos y en el 42,8% el infraespinoso con un tamaño medio de rotura de 34,5 mm (DE: 11,2). El tiempo entre la cirugía y la evaluación fue, por término medio, de 9 meses. La escala de Constant postoperatoria fue, por término medio, de 77,4 (DE: 9,0). No se presentaron complicaciones en la cirugía o falla de los anclajes. Solo un paciente presentó capsulitis adhesiva temprana, que se trató con movilización articular, con la cual se logró normalizar todos los arcos de movilidad. Discusión La técnica doble MAC para la reparación artroscópica de las lesiones grandes y masivas del manguito de los rotadores es una técnica segura y efectiva, con buenos resultados funcionales evaluados a medio plazo y un porcentaje de satisfacción superior al 90%. Nivel de evidencia clínica Nivel IV.

Background Massive ruptures of the rotator cuff represent one of the most complex lesions that can be faced by the orthopaedic shoulder surgeon, and pose a great challenge to achieve satisfactory clinical results. The aim of this study is to describe the clinical outcomes of a new surgical technique for the repair of large and massive rotator cuff injuries used in a specialised orthopaedic clinic during a period of 3 years. Materials and methods A descriptive study was carried out on a cohort of patients with large and massive lesions of the rotator cuff, diagnosed by direct arthro-resonance, and who met criteria for arthroscopic repair. They underwent repair using a new technique called double MAC (Mason-Allen configuration). The post-surgical outcomes were measured using the Constant scale, and the presence of complications and the level of patient satisfaction with the procedure were analysed as outcomes. Results There were 21 patients (10 men and 11 women) with mean age of 59.4 (SD: 8.2) years at the time of surgery. A supraspinatus rupture was present in all (100%) of patients, and an infraspinatus rupture was present in 42.8%.. The mean size of the tear was 34.5 mm (SD: 11.2). Mean time between surgery and assessment was 9 months. Mean post-operative Constant score was 77.4 (SD: 9.0). There were no surgical complications or anchor failure. An early adhesive capsulitis was diagnosed and managed with articular mobilisation, with subsequent improvement in range of motion. Discussion Double MAC technique for arthroscopic repair of large and massive RCT is a safe and effective technique, with good clinical outcomes in the medium term and a patient satisfaction of over 90%. Evidence Level IV.

Simultaneous Top and Bottom Perovskite Interface Engineering by Fullerene Surface Modification of Titanium Dioxide as Electron Transport Layer.

Optimization of the interface between the electron transport layer (ETL) and the hybrid perovskite is crucial to achieve high-performance perovskite solar cell (PSC) devices. Fullerene-based compounds have attracted attention as modifiers on the surface properties of TiO2, the archetypal ETL in regular n-i-p PSCs. However, the partial solubility of fullerenes in the aprotic solvents used for perovskite deposition hinders its application to low-temperature solution-processed PSCs. In this work, we introduce a new method for fullerene modification of TiO2 layers derived from nanoparticles (NPs) inks. Atomic force microscopy characterization reveals that the resulting ETL is a network of TiO2-NPs interconnected by fullerenes. Interestingly, this surface modification enhances the bottom interface of the perovskite by improving the charge transfer as well as the top perovskite interface by reducing surface trap states enhancing the contact with the p-type buffer layer. As a result, rigid PSCs reached a 17.2% power conversion efficiency (PCE), while flexible PSCs exhibited a remarkable stabilized PCE of 12.2% demonstrating the potential application of this approach for further scale-up of PSC devices.

Optimization of the Ag/PCBM interface by a rhodamine interlayer to enhance the efficiency and stability of perovskite solar cells.

Effective control of the interface between the metal cathode and the electron transport layer (ETL) is critical for achieving high performance p-i-n planar heterojunction perovskite solar cells (PSCs). Several organic molecules have been explored as interlayers between the silver (Ag) electrode and the ETL for the improvement in the photovoltaic conversion efficiency (PCE) of p-i-n planar PSCs. However, the role of these organic molecules in the charge transfer at the metal/ETL interface and the chemical degradation processes of PSCs has not yet been fully understood. In this work, we systematically explore the effects of the interfacial modification of the Ag/ETL interface on PSCs using rhodamine 101 as a model molecule. By the insertion of rhodamine 101 as an interlayer between Ag and fullerene derivatives (PC60BM and PC70BM) ETLs improve the PCE as well as the stability of p-i-n planar PSCs. Atomic force microscopy (AFM) characterization reveals that rhodamine passivates the defects at the PCBM layer and reduces the band bending at the PCBM surface. In consequence, charge transfer from the PCBM towards the Ag electrode is enhanced leading to an increased fill factor (FF) resulting in a PCE up to 16.6%. Moreover, rhodamine acts as a permeation barrier hindering the penetration of moisture towards the perovskite layer as well as preventing the chemical interaction of perovskite with the Ag electrode. Interestingly, the work function of the metal cathode remains more stable due to the rhodamine incorporation. Consequently, a better alignment between the quasi-Fermi level of PCBM and the Ag work function is achieved minimizing the energy barrier for charge extraction. This work contributes to reveal the relevance of proper interfacial engineering at the metal-cathode/organic-semiconductor interface.

Self-Functionalization Behind a Solution-Processed NiOx Film Used As Hole Transporting Layer for Efficient Perovskite Solar Cells.

Fabrication of solution-processed perovskite solar cells (PSCs) requires the deposition of high quality films from precursor inks. Frequently, buffer layers of PSCs are formed from dispersions of metal oxide nanoparticles (NPs). Therefore, the development of trustable methods for the preparation of stable colloidal NPs dispersions is crucial. In this work, a novel approach to form very compact semiconducting buffer layers with suitable optoelectronic properties is presented through a self-functionalization process of the nanocrystalline particles by their own amorphous phase and without adding any other inorganic or organic functionalization component or surfactant. Such interconnecting amorphous phase composed by residual nitrate, hydroxide, and sodium ions, proved to be fundamental to reach stable colloidal dispersions and contribute to assemble the separate crystalline nickel oxide NPs in the final film, resulting in a very homogeneous and compact layer. A proposed mechanism behind the great stabilization of the nanoparticles is exposed. At the end, the self-functionalized nickel oxide layer exhibited high optoelectronic properties enabling perovskite p-i-n solar cells as efficient as 16.6% demonstrating the pertinence of the presented strategy to obtain high quality buffer layers processed in solution at room temperature.

Surface chemistry and interfacial charge-transfer mechanisms in photoinduced oxygen exchange at O2-TiO2 interfaces.

Experimental results obtained over the last three decades on photoinduced oxygen isotopic exchange (POIE) of TiO2 oxygen atoms with those of adsorbed water molecules and gaseous O2 are analyzed in the light of recent information from the literature on the interaction of water and O2 species with the TiO2 surface (obtained by application of surface spectroscopy techniques in combination with high-resolution scanning tunnelling microscopy). The analysis emphasizes the singular role that bridging oxygen ions and bridging oxygen vacancies play in TiO2 surface chemistry and interfacial electron transfer at the gas phase-TiO2 interface in the absence and presence of water. The observed competition between POIE and the photo-oxidation (PO) of organic compounds is analyzed in terms of the recently developed direct-indirect (D-I) kinetic model for heterogeneous photocatalysis (D. Monllor-Satoca et al., Catal. Today, 2007, 129, 247, and references therein).