Platinum nanoclusters in silica: Photoluminescent properties and their application for enhancing the emission of silicon nanocrystals in an integrated configuration

"We studied photoluminescence of ion implanted platinum nanoclusters embedded in silica. Pt ions were implanted at 2 MeV and the Pt nanoclusters were then nucleated by thermal treatment under either argon, air, or a reducing atmosphere of hydrogen and nitrogen. The nanoclusters showed broad photoluminescence spectra (400 to 600 nm) with a maximum intensity at 530 nm. The photoluminescence intensity of the Pt nanoclusters was sensitive to the ion fluence used during the ion implantation, and luminescence quenching was observed in samples fabricated at high Pt-ion fluence. A hybrid system composed of silicon nanocrystals and platinum nanoclusters embedded in a silica matrix was also made. The photoluminescence of the hybrid system spanned the entire visible spectrum, and emission from the silicon nanocrystals was enhanced.

Prolazna apneja u ovaca: alternativna metoda za uzastopno uzimanje uzoraka mokraće.

Urine samples are necessary in order to carry out many veterinary diagnostic and research protocols. In ovine, these samples are usually obtained through catheterization, but a transitory apnoea could be an easy way to obtain urine samples. This is achieved by preventing air from entering through the nostrils and mouth in sheep, for a short period of time, always less than 1 minute. The results of this transitory apnoea demonstrated that urine characteristics (pH, density and proteinuria) were not different from samples obtained by bladder catheterization. There were no differences in the blood parameters studied (cortisol, glycaemia, total proteins, haematocrit and total and differential leucocyte counts) either, when compared with the control group of catheterized animals, or with the measured values before or after sampling. In conclusion this system could be considered an easy and effective method to obtain urine samples, without causing stress to the sheep and avoiding the alterations to the blood and urinary parameters measured.Prikupljanje uzoraka mokraće nužno je radi provođenja mnogih veterinarskih dijagnostičkih postupaka i znanstvenih istraživanja. Ti se uzorci u ovaca obično uzimaju kateterizacijom. No, prolazna apneja može biti jednostavan način uzimanja uzoraka mokraće u ovaca. To se može postići zatvaranjem nosnica i gubice u kratkom vremenu, uvijek manje od jedne minute. Rezultati pretrage mokraće prikupljene nakon prolazne apneje pokazali su da značajke mokraće (pH, gustoća i proteinurija) nisu bile različite od onih dobivenih pretragom uzoraka uzetih kateterizacijom mokraćnog mjehura. Nije bilo razlike u pretraženim krvnim pokazateljima (kortizolu, glikemiji, ukupnim proteinima, hematokritu, ukupnim leukocitima i diferencijalnoj krvnoj slici) u usporedbi s kontrolnom skupinom kateteriziranih životinja, a ni u usporedbi s izmjerenim vrijednostima prije i nakon uzimanja uzoraka. Može se zaključiti da je opisani način uzimanja uzoraka jednostavan i učinkovit bez izazivanja stresa u ovaca i ne dovodi do promjena u pokazateljima krvi i mokraće

Evaluación de la atención en deportistas de artes marciales : expertos vs. novatos

El objetivo del estudio fue determinar las diferencias en el desempeño de una tarea de atención en relación con la pericia en artes marciales. Participaron 12 deportistas de artes marciales expertos y 13 novatos. Se les aplicó el Test of Variables of Attention (Greenberg, 1996) y se analizaron los datos de la prueba para cada variable, condición y segmentos en los que se divide, con un método estadístico no-paramétrico de permutaciones. Las comparaciones intergrupos indicaron una tendencia a que el puntaje global de Trastorno por Déficit de Atención e Hiperactividad (TDAH) de la prueba fuera mejor en los expertos que en los novatos. Se hizo un análisis intragrupo para conocer el comportamiento de cada grupo a lo largo de la prueba; los resultados indicaron que los deportistas expertos muestran mayor consistencia en el número de aciertos y tiempos de reacción a lo largo de la prueba, lo que se traduce como un mejor desempeño cuando se compara con la forma en que los deportistas novatos responden a la tarea. Los resultados sugieren que el entrenamiento físico y mental de las disciplinas de artes marciales podría producir una mejora en las capacidades de atención de los deportistas.The aim of this study is to determine differences in the performance of an attention-related task involving martial arts skills. 12 expert martial arts athletes and 13 novices took part, performing the Test of Variables of Attention (Leark, Greenberg, Kindschi, Dupuy and Hughes, 2007). Using a non-parametric statistical permutation method, the test data for each variable, condition and segment of the test was analysed. Comparisons of the groups showed a trend toward a higher global Attention Deficit Hyperactivity Disorder (ADHD) score by the expert athletes as compared with the novices. In order to find out each group's performance during the test, a statistical intra-group analysis was performed. Generally, the results revealed more consistent accuracy and response times by the experts than by the novice athletes. The results suggest that physical and mental training in the martial arts may increase the attention skills of sportsmen and women.O objectivo do estudo foi determinar as diferenças no desempenho de uma tarefa atencional tendo em conta a perícia em artes marciais.Participaram no estudo 12 desportistas especialistas em artes marciais e 13 iniciantes. Foi aplicado aos participantes o Test of Variables of Attention (Greenberg, 1996) e analisaram-se os dados do teste para cada variável, condição e segmentos em que se dividem, através de um método estatístico nãoparamétrico de permutações. As comparações intergrupos indicaram uma tendência para que a pontuação global de Transtorno do Défice de Atenção e Hiperactividade (TDAH) fosse maior nos especialistas do que nos iniciantes. Foi realizada uma análise intragrupo para conhecer o comportamento de cada grupo ao longo da prova; os resultados indicaram que os desportistas especialistas revelaram maior consistência no número de acertos e tempos de reacção ao longo da prova, o que se traduz num melhor desempenho quando comparados com a forma como os desportistas iniciantes respondem à tarefa. Os resultados sugerem que o treino físico e mental das disciplinas de artes marciais poderia produzir uma melhoria nas capacidades atencionais dos desportistas

Paracoccidioidomicose do sistema nervoso central: análise de 13 casos

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by Paracoccidioides brasiliensis, prevalent in Latin America, particularly in Brazil. Central nervous system (CNS) involvement occur in about 10% of cases. Thirteen patients with PCM involving CNS were studied considering clinical manifestation, neuroradiology and treatment modalities. Age ranged from 30 to 71 years-old (M=47.1 +/- 11.6 Me=46). There were eleven men and two women. the most frequent symptoms were motor deficits (53.8%), cognitive disturbance (53.8%), weight loss (46.1%), headaches (46.1%) and seizures (46.1%). the diagnosis was confirmed by the demonstration of P. brasiliensis. Granulomatous forms were present in all patients. Four (30.8%) of them had also meningeal involvement (mixed form). Computerized tomography (CT) scans were obtained in all cases and magnetic resonance imaging (MRI) was used in one case. Serology for HIV was done in ten patients (76.9%), and all the tests were negatives. Amphotericin B was used in twelve patients (92.3%), one of them by intraventricular infusion. in eight patients (61.5%), trimethopim and sulfamethoxazole were used, and, in two (15.4%), sulfadiazine and pirimetamine. Fluconazole, ketoconazole and itraconazole were each one used in a different patient as well. Six patients died (46.1%) and seven (53.9%) had satisfatory outcome. the follow-up period ranged from 2 to 74 (M=30.9) months. in conclusion, the CNS involvement in paracoccidioidomycosis is more frequent and more serious than thought before. the clinical manifestations, CT scans and MRI findings are not specific of paracoccidioidomycosis.Clin Neurol & Neurocirurgia Santa Casa Belo Horiz, Belo Horizonte, MG, BrazilMestre Med Santa Casa Belo Horizonte, Belo Horizonte, MG, BrazilUNIFESP, Escola Paulista Med, São Paulo, BrazilServ Neurocirurg Santa Casa, Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Dept Bioquim & Imunol, Inst Ciencias Biol, Belo Horizonte, MG, BrazilPrograma Pos Grad Santa Casa, Belo Horizonte, MG, BrazilUNIFESP, Escola Paulista Med, São Paulo, BrazilWeb of Scienc

Synthesis of Gold Nanoparticles and Incorporation to a Porous Nickel Electrode to Improve its Catalytic Performance Towards the Hydrogen Evolution Reaction

[EN] Gold nanoparticles (AuNPs) were successfully synthesized by a facile chemical reduction method in the presence of the stabilizer polyvinylpyrrolidone and characterized by UV-vis spectroscopy and transmission electron microscopy. The gold nanoparticles were then incorporated onto the surface of a porous Ni electrode by simple addition of the nanoparticles suspension, followed by heat treatment at 350 degrees C for 1 h under nitrogen atmosphere. The modified electrode was morphologically characterized by field emission scanning electron microscopy. Then, the effect of the modification with Au nanoparticles was studied in the hydrogen evolution reaction (HER) by pseudo-steady-state polarization curves and electrochemical impedance spectroscopy (EIS), at different temperatures and compared with a pure porous Ni electrode. The modified electrode showed a clear improvement in its catalytic performance mainly due to the intrinsic catalytic activity of the Au nanoparticles. From the Tafel representations and the EIS, it was estimated that the HER on the electrode modified with AuNPs takes place by the Volmer-Heyrovsky mechanism.Ramiro Medina Orta is grateful to Consejo Nacional Ciencia y Tecnologia and Consejo Potosino de Ciencia y Tecnologia for the doctorate scholarship 472041. Also, he wishes to thank the Instituto de Metalurgia of Universidad Autonoma de San Luis Potosi for the opportunity of a research stay. We also thank Dr. Nubia Arteaga Larios and M.M.I.M. Martha Alejandra Lomeli Pacheco (Instituto de Metalurgia, Universidad Autonoma de San Luis Potosi) for their help with the UV-vis spectroscopy.Medina-Orta, R.; Labrada-Delgado, GJ.; Silva-Pereyra, HG.; Ortega Navarro, EM.; Pérez-Herranz, V.; Sánchez-Loredo, MG. (2022). Synthesis of Gold Nanoparticles and Incorporation to a Porous Nickel Electrode to Improve its Catalytic Performance Towards the Hydrogen Evolution Reaction. Electrocatalysis. 13(1):47-61. https://doi.org/10.1007/s12678-021-00690-7476113

SPARC4: A Simultaneous Polarimeter and Rapid Camera in 4 Bands

We present the basic concept of a new astronomical instrument: SPARC4 - Simultaneous Polarimeter and Rapid Camera in 4 bands. SPARC4 combines in one instrument: (i) photometric and polarimetric modes; (ii) sub-second time-resolution in photometric mode and excellent time-resolution in polarimetric mode; (iii) simultaneous imaging in four broad-bands for both modes. This combination will make SPARC4 a unique facility for ground-based optical observatories. Presently, the project is in its conceptual design phase.Comment: Poster presented at "Stellar Polarimetry: From birth to death". This article has been submitted to AIP Conference Proceedings. After it is published, it will be found at http://www.aip.or

Profile and professional expectations of medical students from 11 Latin American countries: the Red-LIRHUS project

Background Latin America is undergoing a human resource crisis in health care in terms of labor shortage, misdistribution and poor orientation to primary care. Workforce data are needed to inform the planning of long-term strategies to address this problem. This study aimed to evaluate the academic and motivational profile, as well as the professional expectations, of Latin American medical students. Results We conducted an observational, cross-sectional, multi-country study evaluating medical students from 11 Spanish-speaking countries in 2011–2012. Motivations to study medicine, migration intentions, intent to enter postgraduate programs, and perceptions regarding primary care were evaluated via a self-administered questionnaire. Outcomes were measured with pilot-tested questions and previously validated scales. A total of 11,072 valid surveys from 63 medical schools were gathered and analyzed. Conclusions This study describes the profile and expectations of the future workforce being trained in Latin America. The obtained information will be useful for governments and universities in planning strategies to improve their current state of affairs regarding human resources for health care professions

Fortalecimiento de gestiones a través del Centro de Información de Actividades Porcinas (CIAP) para el desarrollo sustentable de pequeños y medianos productores porcinos familiares de la zona de influencia de la Facultad de Ciencias Agrarias de la Universidad Nacional de Rosario

Fortalecimiento de gestiones a través del Centro de Información de Actividades Porcinas (CIAP) para el desarrollo sustentable de pequeños y medianos productores porcinos familiares de la zona de influencia de la Facultad de Ciencias Agrarias de la Universidad Nacional de RosarioFil: Silva, Patricia. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin