Self-Supported Spray-Coated NiFe-LDH Catalyst on a Stainless Steel Substrate for Efficient Oxygen Evolution Reaction.

In the quest for more efficient and cost-effective electrocatalytic systems, careful selection of catalysts and substrates plays a pivotal role. This study introduces an approach by synthesizing and depositing NiFe-layered double hydroxide (NiFe-LDH) catalysts on commercial AISI 304 substrates by using a low-temperature spray-coating technique. Through systematic investigations, the influence of processing conditions, such as the synthesis, ultrasonic power for having a stable nanoparticle's dispersion, and spray cycle optimization on the electrochemical and morphological properties of the coatings, is thoroughly explored. The results showcase exceptional catalytic performance, achieving an overpotential of 230 mV at 10 mA/cm2, with enhanced stability even at high current densities of 500 mA/cm2. The study highlights the significance of meticulous processing optimization and presents a scalable methodology that holds great potential for developing catalysts for oxygen evolution reactions (OER) and facilitates their integration into industrial processes.

3D-Printable PLA/Mg Composite Filaments for Potential Bone Tissue Engineering Applications.

Magnesium (Mg) is a promising material for bone tissue engineering applications due to it having similar mechanical properties to bones, biocompatibility, and biodegradability. The primary goal of this study is to investigate the potential of using solvent-casted polylactic acid (PLA) loaded Mg (WE43) composites as filament feedstock for fused deposition modeling (FDM) 3D Printing. Four PLA/Magnesium (WE43) compositions (5, 10, 15, 20 wt%) are synthesized and produced into filaments, then used to print test samples on an FDM 3D printer. Assessments are made on how Mg incorporation affected PLA's thermal, physicochemical, and printability characteristics. The SEM study of the films shows that the Mg particles are uniformly distributed in all the compositions. The FTIR results indicate that the Mg particles blend well with the polymer matrix and there is no chemical reaction between the PLA and the Mg particles during the blending process. The thermal studies show that the addition of Mg leads to a small increase in the melting peak reaching a maximum of 172.8 °C for 20% Mg samples. However, there are no dramatic variations in the degree of crystallinity among the Mg-loaded samples. The filament cross-section images show that the distribution of Mg particles is uniform up to a concentration of 15% Mg. Beyond that, non-uniform distribution and an increase in pores in the vicinity of the Mg particles is shown to affect their printability. Overall, 5% and 10% Mg composite filaments were printable and have the potential to be used as composite biomaterials for 3D-printed bone implants.

Role of the base Cs2CO3 on the palladium-catalyzed intramolecular cyclization of two bromoindole derivatives to yield paullone-type products.

Reactions for the palladium-catalyzed intramolecular cyclization of the o-bromoindole and the o-bromo-N-methyl-indole derivatives in the presence and absence of base (Cs2CO3) were explored through DFT calculations. For the base-free reactions, the palladium atom firstly interacts with the aromatic rings of the indole molecule to yield a stable adduct. Once this adduct has been formed, reaction proceeds readily to the oxidative addition intermediate that arises from the insertion of the metal atom into the C-Br bond of the organic fragment. Further steps leading to the paullone (or dimethyl paullone) product, mainly those involving the metalation and deprotonation of the inserted intermediate, are not energetically viable for these reactions. When the effect of the base on the metalation-deprotonation steps is modeled by replacing the bromide ion with CO32- in the metal-inserted structure, a feasible pathway connecting the oxidative addition intermediate with the paullone-type product was located for each of the investigated reactions. The results emerging from this study suggest that palladium can insert into the C-Br bond of the indole derivatives to yield the oxidative addition intermediate (without participation of the base). However, the metalation and deprotonation steps that evolve to the paullone-type product take place via a concerted action involving both the metal and the base. Metalation and deprotonation steps that evolve to the paullone-type product take place via a concerted action involving both the metal and the base.

Principales hábitos de medicación por los propietarios de caninos que acuden a consulta veterinaria en Pasto, Nariño, Colombia / Main medication habits in dogs made by theirowners who come to veterinary consultation in Pasto, Nariño, Colombia

El objetivo de este trabajo es determinar los hábitos de medicación en caninos por parte de los propietarios, antes de la consulta médica, y clasificar los medicamentos utilizados por grupo farmacológico. Para ello se realizó un estudio de utilización de medicamentos por medio de un cuestionario dirigido a 196 propietarios en seis clínicas veterinarias. Se encontró que el 95% de los propietarios medicaban a sus mascotas antes de la consulta médica. En el 6,4 % de los casos no coincidió la medicación que administraron con el diagnóstico final emitido por el médico veterinario, ya que la patología derivaba de otro sistema. El 63% optó por utilizar la vía oral como medio para administrar medicamentos. Las dos formas farmacéuticas más utilizadas fueron la líquida (55,91%) y la sólida (32,8%). El grupo farmacológico más utilizado fue el de los analgésicos no esteroidales (24,73%). Según la correlación fármaco-dosis- frecuencia-patología, el 98% de los propietarios no administraron adecuadamente los medicamentos. Se concluye que los propietarios medican a sus mascotas sin recomendación del médico veterinario, la mayoría de ellos lo realizan con productos no aprobados para uso en caninos, y las dosis utilizadas son incorrectas y no tienen en cuenta la frecuencia de administración.

The main objective of this work is determining the habits of medication in dogs by the owners before the veterinary consultation, and to classify the drugs used by pharmacological group. A study of drug use was performed by means of a questionnaire sent to 196 owners in six veterinary clinics. In 95% of owners, medication habits were evidenced before medical consultation. In 6.4% of cases, administered medication to pets did not match with the final diagnosis issued by the veterinarian, since the pathology derived from another system. 63% opted for using mouth for giving medication. The two pharmaceutical forms most used were liquid (55.91%) and solid (32.8%). The most used pharmacological group was the non-steroidal analgesics (24.73%). According to the drug-dose-frequency-pathology correlation, 98% of owners did not administer medications properly. The findings are: the owners medicate their pets without veterinary doctor recommendation, most of them do it with products which are not approved for being used in dogs, and doses used are incorrect and do not take into account the frequency of administration.

Preliminary design of an actuated imaging probe for generation of additional visual cues in a robotic surgery.

BACKGROUND: The aim of this study was to enhance the visual feedback of surgeons, during robotic surgeries, by designing and developing an actuated 2D imaging probe, which is used in conjunction with the traditional stereoscopic camera of the da Vinci surgical system. The probe provides the surgeon with additional visual cues, overcoming visualization constraints encountered during certain scenarios of robot-assisted minimally invasive surgery. METHODS: The actuated imaging probe is implemented as a master-slave tele-manipulated system, and it is designed to be compatible with the da Vinci surgical system. The detachable probe design enables it to be mounted on any of the EndoWrist(®) instruments of the robot and is controlled by the surgeon using a custom-made pedal system. The image from the 2D probe is rendered along with the stereoscopic view on the surgeon's console. RESULTS: The experimental results demonstrate the effectiveness of the proposed actuated imaging probe when used as an additional visualization channel and in surgical scenarios presenting visual problems due to tissue occlusion. CONCLUSION: The study shows the potential benefits of an additional actuated imaging probe when used in conjunction with traditional surgical instruments to perform surgical tasks requiring visualization from multiple orientations and workspaces.

Fracturas supracondíleas del húmero en niños entre 2 y 14 años. Perfil demográfico y de tratamiento en el Hospital Pablo Tobón Uribe, Medellín, Colombia / Supracondylar fractures of the humerus in children aged 2-14 years. Demographic profile and therapeutic approach at a third-level hospital in Medellín, Colombia

Introducción: las fracturas supracondíleas del húmero distal son las lesiones más frecuentes de tratamiento quirúrgico en la población pediátrica. Los informes sobre el perfil demográfico y el enfoque terapéutico de las mismas en Medellín son limitados; este trabajo se llevó a cabo para conocer la epidemiología local de estas lesiones y detectar en el seguimiento los aciertos y errores del tratamiento como base para desarrollar estudios de mayor complejidad. Materiales y métodos: mediante una búsqueda exhaustiva en los registros de historias clínicas electrónicas se encontraron 205 casos de fracturas supracondíleas del húmero en niños entre dos y 14 años que ingresaron al Servicio de Urgencias del Hospital Pablo Tobón Uribe entre enero de 2005 y septiembre de 2009. Se analizaron en ellas los aspectos demográficos y terapéuticos. Resultados: el 61,5% de los pacientes fueron varones, la media de la edad fue de 6,6 años, en 62,4% de los casos la fractura afectó el lado izquierdo. La clasificación (Gartland) fue como sigue: tipo I: 41,5%; tipo II: 12,2%; tipo III: 46,3%. El 95,6% fueron fracturas cerradas. Se hizo tratamiento quirúrgico en 103 casos (50,2%). El tiempo promedio entre el ingreso y la cirugía fue de 6,7 horas. La técnica quirúrgica más frecuente fue la reducción cerrada con fijación percutánea con clavos cruzados (45,6% de los casos). Se observaron 31 casos (15,1%) de lesiones neurológicas, 28 de ellas del nervio ulnar; nueve de las 31 lesiones se registraron en la evaluación posquirúrgica inmediata, todas ellas en pacientes tratados con clavos cruzados. No se registraron lesiones vasculares ni síndromes compartimentales.Conclusión: esta serie presenta el estado actual del perfil demográfico de los pacientes con fracturas supracondíleas del húmero distal en niños y de las modalidades de tratamiento en un hospital de tercer nivel de la ciudad de Medellín. Los resultados pueden ser la base para futuros estudios de mayor elaboración metodológica.

Introduction: Supracondylar fractures of the distal humerus are the most frequent injuries that require surgical treatment in the pediatric population. Reports on the demographic profile and the therapeutic approach of patients with these fractures in Medellín, Colombia, are limited. This study was carried out in order to know the local epidemiology of these lesions, and to detect during the follow-up the good therapeutic decisions and the mistakes, as a basis for more complex research. Materials and methods: A comprehensive search was conducted of electronic medical records at a thirdlevel hospital; 205 cases of supracondylar fractures of the humerus were found in children aged 2-14 years, admitted to the emergency service (Hospital Pablo Tobón Uribe) between January 2005 and September 2009. Demographic and therapeutic aspects were analyzed. Results: Average age was 6.6 years; 61.5% of the patients were males. In 62.4% fractures affected the left side. Classification (Gartland) was as follows: type I: 41.5%; type II: 12.2%; type III: 46.3%. Fractures were closed in 95.5% of the patients. Treatment was surgical in 103 patients (50.2%). Average time between admission and surgery was 6.7 hours. The most frequently used surgical technique was closed reduction with percutaneous fixation with crossed pins (45.6%). There were 31 cases of neurological injuries, 28 of which affected the ulnar nerve. Nine of the 31 were observed in the immediate postoperative evaluation and all of these occurred in patients treated with crossed pins. There were no vascular injuries or compartment syndromes. Conclusion: This series presents the current demographic profile of patients with supracondylar fractures of the distal humerus in children, as well as the therapeutic approaches in a third-level hospital in Medellín, Colombia. These results may be the basis for future more complex studies.

Obstrucción estrangulante del intestino grueso en equinos: evaluación clínica y tratamiento quirúrgico en dos casos / Strangulation obstructions of large intestine in horses: clinical evaluation and surgical treatment in two cases

La obstrucción estrangulante es la combinación de obstrucción simple del tracto gastrointestinal del equino acompañado de bloqueo del abastecimiento circulatorio, lo cual causa severa enfermedad intestinal. Esta afección es comúnmente conocida como Síndrome Abdominal Agudo o Cólico. La incidencia de esta afección es considerada baja con una mortalidad alta dependiendo del segmento anatómico involucrado y del tiempo con que se intervenga quirúrgicamente el paciente. En el presente trabajo se reportan los hallazgos clínicos e histopatológicos, el tratamiento quirúrgico, la evolución clínica y el manejo medico post-quirúrgico de dos casos de obstrucciones estrangulantes del colon mayor en equinos referidos a la Clínica Veterinaria Dr. “Luis Medina”. La historia, sintomatología clínica y pruebas de laboratorio orientaron el diagnóstico, el cual fue confirmado a través de laparotomía exploratoria, la resolución de cada caso fue acompañada con un estudio histológico del segmento intestinal afectado. La resolución en el caso número uno fue por enterotomía de vaciado, mientras que el caso dos fue tratado con reseción del colon mayor con entero anastomosis latero-lateral. Ambos casos sobrevivieron, observándose mejor progreso clínico post-quirúrgico en el caso número dos.

Strangulation obstructions are external vascular constriction with simultaneous blockage of intestinal lumen. It has also been referred cause severe intestinal disease in the horses and commonly related colic. The incidence of this lesion is low with high fatality influenced by anatomic segment involved and rapid surgical intervention at the horse. This paper report the history, clinical signs, histopathologic findings, surgical ma- nagement, clinical progress and post-surgical treatment in two case of strangulation of the large colon in horses sent to the veterinary clinic “Dr. Luis Medina”. History, physical examination, laboratory test and exploratory laparatomy were used for diagnostic purpose. The resolution of each case has been completed with a histopatlogic study of the anatomic segment involved. The resolution in the case number one was for pelvic flexure enterotomy to decompress the colon torsion. The case number two was threatened with large colon resection and sideto-side anastomosis of left dorsal and ventral colons. Both cases survived however the case two have better clinical progress post-surgical.

ISOLATION OF HUMAN BONE MARROW MESENCHYMAL STEM CELLS AND EVALUATION OF THEIR OSTEOGENIC POTENTIAL

Human bone marrow mesenchymal stem cells (hBMSCs) comprise a cell population capable of self-renewal and multilineage differentiation commonly isolated from bone marrow aspirates of large bones. Their osteogenic potential has been extensively exploited for the biological evaluation of scaffolds or biomaterials with applications in bone tissue engineering. This work aimed to isolate hBMSCs from femoral heads of patients undergoing total hip arthroplasty and to evaluate their osteogenic potential. Briefly, the trabecular bone was extracted and mechanically disaggregated; the released cells were cultured and non-adherent cells were removed after 4 days. The osteogenic potential was evaluated at the fifth passage after 14 and 20 days of induction, comparing cultures with and without osteogenic supplements, via Alizarin red staining and the quantification of the gene expression levels of the osteogenic markers collagen type I, osteonectin and bone sialoprotein through real-time RT-PCR. The obtained hBMSCs presented a stable undifferentiated phenotype after prolonged cell culture, matrix mineralization capabilities and expression of osteoblast phenotype upon osteogenic induction. The three markers were up-regulated in cultures under osteogenic conditions and 2 fold differences in their expression levels were found to be significant for the onset of the differentiation process. The obtained hBMSCs may have applications on the in vitro evaluation of the osteoinductivity of different biomaterials, bioactive molecules or tissue engineering scaffolds.

Las células madre mesenquimatosas de médula ósea humana (abreviadas hBMSCs) constituyen una fuente de células auto-renovables con alto potencial de diferenciación, comúnmente aisladas a partir de los aspirados medulares en huesos largos. Su diferenciación hacia el linaje osteogénico, por ejemplo, ha sido ampliamente utilizada para la evaluación biológica de biomateriales o matrices con aplicaciones en la ingeniería de tejidos óseos. El objetivo de este trabajo consistió en aislar hBMSCs a partir de la cabeza femoral de pacientes sometidos a artroplastia total de cadera, así como evaluar su potencial osteogénico. Brevemente, se extrajo el hueso esponjoso y se disgregó mecánicamente; las células desprendidas se cultivaron y las células no adherentes se eliminaron luego de 4 días. El potencial osteogénico se evaluó en la quinta generación de cultivo, mediante ensayos de diferenciación a 14 y 20 días donde se compararon cultivos con y sin suplementos osteogénicos. La evaluación se realizó mediante tinción con Alizarina Roja y la cuantificación de los niveles de expresión génica de los marcadores osteogénicos colágeno tipo I, osteonectinca y sialoprotiena ósea mediante RT-PCR en tiempo real. Las hBMSCs obtenidas presentaron un fenotipo no-diferenciado estable, así como la capacidad de mineralizar la matriz extracelular y expresar un fenotipo similar al osteoblasto durante la inducción osteogénica. Los tres marcadores evaluados se sobre-expresaron en los cultivos en condiciones osteogénicas, y se encontró que cambios hasta de 2X en sus niveles de expresión son relevantes para el desarrollo del proceso de diferenciación. El modelo de hBMSCS presentado podría ser utilizado para la evaluación in vitro de la osteoinductividad de diferentes biomateriales, moléculas bioactivas o matrices para ingeniería de tejidos.