Lead-free organic-inorganic azetidinium alternating metal cation bromide: [(CH2)3NH2]2AgBiBr6, a perovskite-related absorber.

In the last decade, organic-inorganic hybrid halide perovskite materials have developed into a very large research area in photovoltaics and optoelectronics as promising light harvesters. Lead-free double perovskites have recently been investigated as an environmentally friendly alternative to the lead-containing compositions. However, lead-free organic-inorganic hybrid halide double perovskites have so far rarely been produced due to a certain complexity in their synthesis. A number of small molecular cations have been investigated, but compositions containing azetidinium, which is a 4-membered heterocyclic molecular ring, on the A-site have hardly been considered. This study investigates the potential of [(CH2)3NH2]2AgBiBr6 as an optical absorber in photovoltaics or optoelectronics. The use of this alternative cation changes the crystal symmetry significantly. Columns of alternating metal cation form which are separated by the organic ions. While crystal symmetry is rather different from the perovskites, the overall properties as an absorber are similar. It is thus worthwhile to further investigate alternate hybrid compositions which form into other symmetries than the perovskite base structure.

Rare-earth doped BiFe0.95Mn0.05O3 nanoparticles for potential hyperthermia applications.

Ionic engineering is exploited to substitute Bi cations in BiFe0.95Mn0.05O3 NPs (BFM) with rare-earth (RE) elements (Nd, Gd, and Dy). The sol-gel synthesized RE-NPs are tested for their magnetic hyperthermia potential. RE-dopants alter the morphology of BFM NPs from elliptical to rectangular to irregular hexagonal for Nd, Gd, and Dy doping, respectively. The RE-BFM NPs are ferroelectric and show larger piezoresponse than the pristine BFO NPs. There is an increase of the maximum magnetization at 300 K of BFM up to 550% by introducing Gd. In hyperthermia tests, 3 mg/ml dispersion of NPs in water and agar could increase the temperature of the dispersion up to ∼39°C under an applied AC magnetic field of 80 mT. Although Gd doping generates the highest increment in magnetization of BFM NPs, the Dy-BFM NPs show the best hyperthermia results. These findings show that RE-doped BFO NPs are promising for hyperthermia and other biomedical applications.

Laser Ablation of NiFe2O4 and CoFe2O4 Nanoparticles.

Pulsed laser ablation in liquids was utilized to prepare NiFe2O4 (NFO) and CoFe2O4 (CFO) nanoparticles from ceramic targets. The morphology, crystallinity, composition, and particle size distribution of the colloids were investigated. We were able to identify decomposition products formed during the laser ablation process in water. Attempts to fractionate the nanoparticles using the high-gradient magnetic separation method were performed. The nanoparticles with crystallite sizes in the range of 5-100 nm possess superparamagnetic behavior and approximately 20 Am2/kg magnetization at room temperature. Their ability to absorb light in the visible range makes them potential candidates for catalysis applications in chemical reactions and in biomedicine.

Role of cooperative factors in the photocatalytic activity of Ba and Mn doped BiFeO3 nanoparticles.

The escalated photocatalytic (PC) efficiency of the visible light absorber Ba-doped BiFe0.95Mn0.05O3 (BFM) nanoparticles (NPs) as compared to BiFeO3 (BFO) NPs is reported for the degradation of the organic pollutants rhodamine B and methyl orange. 1 mol% Ba-doped-BFM NPs degrade both dyes within 60 and 25 minutes under UV + visible illumination, respectively. The Ba and Mn co-doping up to 5 mol% in BFO NPs increases the specific surface area, energy of d-d transitions, and PC efficiency of the BFO NPs. The maximum PC efficiency found in 1 mol% Ba doped BFM NPs is attributed to a cooperative effect of factors like its increased light absorption ability, large surface area, active surface, reduced recombination of charge carriers, and spontaneous polarization to induce charge carrier separation. The 1 mol% Ba and 5 mol% Mn co-incorporation is found to be the optimum dopant concentration for photocatalytic applications. These properties of co-doped BFO NPs can, e.g., be exploited in the field of water splitting.

Laser Fragmentation Synthesis of Colloidal Bismuth Ferrite Particles.

Laser fragmentation of colloidal submicron-sized bismuth ferrite particles was performed by irradiating a liquid jet to synthesize bismuth ferrite nanoparticles. This treatment achieved a size reduction from 450 nm to below 10 nm. A circular and an elliptical fluid jet were compared to control the energy distribution within the fluid jet and thereby the product size distribution and educt decomposition. The resulting colloids were analysed via UV-VIS, XRD and TEM. All methods were used to gain information on size distribution, material morphology and composition. It was found that using an elliptical liquid jet during the laser fragmentation leads to a slightly smaller and narrower size distribution of the resulting product compared to the circular jet.

Toxoplasma gondii and Trichinella infections in wild boars (Sus scrofa) from Northeastern Patagonia, Argentina.

Wild boar (Sus scrofa) was introduced in many countries of the world and is recognized as carrier of many infectious diseases. Wild game meat consumption is recognized as a source of transmission of Toxoplasma gondii and Trichinella spp. The aim of the present study was to evaluate the prevalence of antibodies to T. gondii and Trichinella spp. in free-range wild boars in Northeastern Argentine Patagonia. Between 2014 and 2018, 144 blood samples and 423 muscle samples from 423 carcasses were collected. To detect T. gondii IgG, 144 sera were processed by an immunofluorescent antibody test, and to detect anti-Trichinella IgG, 125 sera and 304 muscle juice samples were processed by ELISA. Detection of first stage larvae in muscle was performed by artificial digestion. A total of 423 wild boars muscle samples were negative to Trichinella spp. by artificial digestion. Antibodies to Trichinella spp. were detected in 2.4% (3/125) of serum samples and in 1.64% (5/304) of meat juice samples. Antibodies to T. gondii infection were detected in 12.5% (18/144) of the serum samples. This is the first study to reveal the presence of antibodies to T. gondii in wild boars from Argentina. The present results suggest that consumption of raw or undercooked wild boar meat could represent a potential source risk for toxoplasmosis in humans and that Trichinella spp. is infrequent and/or that it circulates in low burdens among wild boars in Northeastern Patagonia.

Aspectos epidemiológicos, clínicos y quirúrgicos de los tumores cerebrales metastásicos / Aspectos epidemiológicos, clínicos e cirúrgicos dos tumores cerebrais metastáticos / Epidemiological, clinical and surgical aspects of metastatic brain tumors

Introducción: los tumores que se diseminan en el cerebro, provenientes de una neoplasia primaria localizada en otros órganos del cuerpo son conocidos como tumores cerebrales metastásicos. Se estima que el 25 por ciento de los tumores malignos en otros lugares del organismo provocan metástasis en la cabeza. Objetivo: sistematizar los aspectos clínicos, epidemiológicos y quirúrgicos de los tumores cerebrales metastásicos, así como las herramientas diagnósticas y terapéuticas necesarias para ofrecerles al enfermo y familiares las mejores alternativas ante la enfermedad. Método: se realizó una revisión narrativa a partir del estudio documental de revisiones sistemáticas, metaanálisis, guías de práctica clínica, artículos originales y tesis doctorales que se encontraron en las bases de datos electrónicas. Resultados: la incidencia de la metástasis cerebral varía en dependencia de la localización del tumor primario. En los adultos, la incidencia más alta se observó entre la quinta y séptima década de vida, sin diferencias en el sexo. Los tumores cerebrales tienen diferentes formas de presentación clínica, entre ellas se encontraron el síndrome de hipertensión intracraneal, signos focales, crisis epilépticas y síndrome endocrino. Los tres componentes primordiales del manejo de pacientes con metástasis cerebral fueron las drogas no quimioterapéuticas y quimioterapéuticas, la intervención quirúrgica para la exéresis tumoral y la radioterapia. Conclusiones: los tumores metastásicos cerebrales constituyen un problema de salud con incidencia creciente, con un cuadro sindrómico complejo y polimorfo, poseen amplio arsenal terapéutico que abarca las drogas no quimioterapéuticas, la quimioterapia, la quirúrgica y la radioterapia las cuales deben ser ajustadas a las características de cada paciente para lograr una sobrevida lo más larga posible, con mayor calidad de vida(AU)

Introduction: tumors that spread in the brain, from a primary neoplasm located in other organs of the body are known as metastatic brain tumors. It is estimated that 25per cent of malignant tumors in other parts of the body cause head metastases. Objective: to systematize the clinical, epidemiological and surgical aspects of metastatic brain tumors, as well as the diagnostic and therapeutic tools necessary to offer the patient and family the best alternatives to the disease. Method: a narrative review was carried out based on the documentary study of systematic reviews, meta-analysis, clinical practice guides, original articles and doctoral theses that were found in the electronic databases. Results: the incidence of brain metastasis varies depending on the location of the primary tumor. In adults, the highest incidence was observed between the fifth and seventh decade of life, without differences in sex. Brain tumors have different forms of clinical presentation, including intracranial hypertension syndrome, focal signs, epileptic seizures and endocrine syndrome. The three primary ISSN 1028-9933 526 components of the management of patients with cerebral metastases were non-chemotherapeutic and chemotherapeutic drugs, surgical intervention for tumor excision and radiotherapy. Conclusions: metastatic brain tumors constitute a health problem with increasing incidence, with a complex syndromic and polymorphic picture, they have a wide therapeutic arsenal that includes non-chemotherapeutic drugs, chemotherapy, surgery and radiotherapy which must be adjusted to the characteristics of each patient to achieve a survival as long as possible, with a better quality of life(AU)

Introdução: tumores que se espalham no cérebro, a partir de uma neoplasia primária localizada em outros órgãos do corpo, são conhecidos como tumores cerebrais metastáticos. Estima-se que 25per cent dos tumores malignos em outras partes do corpo causem metástases na cabeça. Objetivo: sistematizar os aspectos clínicos, epidemiológicos e cirúrgicos dos tumores cerebrais metastáticos, bem como as ferramentas diagnósticas e terapêuticas necessárias para oferecer ao paciente e à família as melhores alternativas para a doença. Método: foi realizada uma revisão narrativa baseada no estudo documental de revisões sistemáticas, metanálises, guias de prática clínica, artigos originais e teses de doutorado encontradas nas bases de dados eletrônicas. Resultados: a incidência de metástases cerebrais varia de acordo com a localização do tumor primário. Nos adultos, a maior incidência foi observada entre a quinta e a sétima década de vida, sem diferenças entre os sexos. Os tumores cerebrais têm diferentes formas de apresentação clínica, incluindo síndrome de hipertensão intracraniana, sinais focais, convulsões epilépticas e síndrome endócrina. Os três componentes principais do tratamento de pacientes com metástases cerebrais foram medicamentos não quimioterápicos e quimioterápicos, intervenção cirúrgica para excisão de tumores e radioterapia. Conclusões: os tumores cerebrais metastáticos constituem um problema de saúde com incidência crescente, com quadro sindrômico e polimórfico complexo, possuem amplo arsenal terapêutico que abrange medicamentos não quimioterápicos, quimioterapia, cirurgia e radioterapia, que devem ser ajustados às características de cada paciente para alcançar a sobrevivência o maior tempo possível, com uma melhor qualidade de vida(AU)

Revascularización endovascular de la enfermedad oclusiva ateroesclerótica crónica de la aorta infrarrenal: reporte de tres casos clínicos / Endovascular revascularization of infrarenal aortic chronic atherosclerotic disease: a report of three clinical cases

La revascularización endovascular de la aorta infrarrenal en pacientes sintomáticos con lesiones oclusivas ateroescleróticas crónicas surge como modalidad terapéutica en casos seleccionados, idealmente en lesiones tipo A y B. Comunicar los resultados inmediatos y el seguimiento a largo plazo, de pacientes con clínica de claudicación intermitente de miembros inferiores, diagnosticados con estenosis significativa de la aorta infrarrenal entre junio de 2002 y enero de 2008. Tres pacientes fueron sometidos a angioplastía percutánea de la aorta infrarrenal. con implante de stent o stent-graft, indicándose al egreso aspirina, clopidogrel y cilostazol, así como rehabilitación. Se realizó seguimiento clínico y por angiotomografía al año. El promedio de estenosis fue de 86,3%, 0% posangioplastia. Durante el seguimiento se evidenció mejoría clínica y ausencia de reestenosis. La angioplastia con balón e implantación de stent ha demostrado ser una técnica segura y efectiva como lo describe la literatura actualmente. Siendo una modalidad de menor costo para pacientes con esta entidad clínica.

Endovascular revascularization of chronic atherosclerotic type A and B lesions of the infrarenal aorta is a therapeutic option in selecte symptomatic patients. Communicate immediate and long-term follow-up autcome of patients with lower limb intermittent claudication with significant infrarenal aortic stenosis diagnosis between June 2002 and January 2008. Three patients underwent percutaneous transluminal angioplasty of the infrarenal aorta with either stent or stent-graft deployment, treated ofter discharge with aspirin, clopidogret and rehabilitation. One year clinical and tomographic follow up was made. Stenosis average was 86.3%, 0% after angioplasty. Clinical improvement and no restenosis were evident during follow-up. Percutaneous transluminal angioplasty with stent deployment seems to be a safe an effective approach to treat these lesions as reported in the literature, at a lower cost on an outpatient basis.

Presillamiento de aneurisma intracraneal en una niña mediante microcirugía y endoscopia asistida / Clipping of intracraneal aneurysm in a girl by means of microsurgery and assisted endoscopy

Se expone el caso clínico de una paciente de 12 años de edad, afectada por un aneurisma intracraneal de la bifurcación carótida derecha, que fue operada satisfactoriamente por medio de microcirugía con endoscopia asistida, puesto que el uso de esa técnica combinada disminuye las craneotomías y retracción del cerebro, permite una mejor visualización durante el acto quirúrgico y reduce la morbilidad operatoria. Este parece ser el primer informe en Cuba sobre el empleo de ambos procederes a la vez para el tratamiento de un aneurisma intracraneal en la infancia(AU)

The clinical case of a 12 year-old patient, affected by an intracraneal aneurysm of the right carotid bifurcation who had a satisfactory surgery by means of microsurgery with assisted endoscopy is exposed, since the use of this combined technique diminishes the craneotomies and brain retraction, it allows a better visualization during the surgical intervention and reduces the surgical morbility. This seems to be the first report in Cuba on the use of both procedures at the same time for the treatment of an intracraneal aneurysm in the childhood(AU)

Presillamiento de aneurisma intracraneal en una niña mediante microcirugía y endoscopia asistida / Clipping of intracraneal aneurysm in a girl by means of microsurgery and assisted endoscopy

Se expone el caso clínico de una paciente de 12 años de edad, afectada por un aneurisma intracraneal de la bifurcación carótida derecha, que fue operada satisfactoriamente por medio de microcirugía con endoscopia asistida, puesto que el uso de esa técnica combinada disminuye las craneotomías y retracción del cerebro, permite una mejor visualización durante el acto quirúrgico y reduce la morbilidad operatoria. Este parece ser el primer informe en Cuba sobre el empleo de ambos procederes a la vez para el tratamiento de un aneurisma intracraneal en la infancia.

The clinical case of a 12 year-old patient, affected by an intracraneal aneurysm of the right carotid bifurcation who had a satisfactory surgery by means of microsurgery with assisted endoscopy is exposed, since the use of this combined technique diminishes the craneotomies and brain retraction, it allows a better visualization during the surgical intervention and reduces the surgical morbility. This seems to be the first report in Cuba on the use of both procedures at the same time for the treatment of an intracraneal aneurysm in the childhood.

Synthesis and biochemical characterization of new phenothiazines and related drugs as MDR reversal agents.

Chemotherapy is one of the most important methods in the treatment of cancer. However, development of drug resistance during chemotherapy is the leading cause of treatment failure and decreased survival in cancer patients. Multidrug resistance (MDR) is one of the extensively studied forms of drug resistance for more than 30 years. The members of ATP-binding cassette protein family are responsible for multidrug resistance with P-glycoprotein as most representative transporter. To overcome multidrug resistance, pharmacological modulation of the transporters by efflux pump inhibitors seem to be the first choice, but preclinical studies did not lead to clinical applications. Therefore, a systematical research for pharmacophor structures is a promising strategy to increase the efficacy of those drugs still influencing multidrug resistance. In this study a range of phenothiazine derivatives was synthesizied with systematical variation of three molecule domains. The biochemical determination of multidrug resistance reversal activity was achieved with the crystalviolet assay on LLC-PK1/MDR1 cells. The results will be discussed considering of hypotheses in the literature directed to new structure-acitivity relationships to overcome drug resistance in the future.

Tumores cerebrales en la infancia / Cerebral tumours in the childhood

Se realiza un estudio descriptivo prospectivo de los pacientes con tumores cerebrales diagnosticados en el Hospital Pediátrico Docente “Pedro Agustín Pérez” de Guantánamo, desde octubre de 2002 a septiembre de 2005, donde se analizan las variables correspondientes a: edad, sexo, síntomas y signos iniciales, estudios de neuroimagen, resultado histológico, tratamiento empleado, evolución y mortalidad. Se encuentra predominio del grupo etario de 11-15 años, sexo masculino. La cefalea fue el síntoma inicial más frecuente, los tumores de cerebelo fueron los que predominaron con correlación clínica, de imagen e histológica. Los gliomas de diferentes grados fueron los tumores encontrados en estudios anatomopatológicos. Los tratamientos combinados fueron los más utilizados, con evolución fatal en 7 casos. Se emiten conclusiones(AU)