In vitro characterization of somatostatin receptors in the human thymus and effects of somatostatin and octreotide on cultured thymic epithelial cells

Somatostatin (SS) and its analogs exert inhibitory effects on secretive and proliferative processes of various cells via high affinity SS receptors (SS-R). SS analogs bind with different affinity to the five cloned SS-R subtypes. Octreotide, an octapeptide SS analog, binds with high affinity to the SS-R subtype 2 (sst2). SS-R have been demonstrated in vivo and in vitro on cells from endocrine and immune systems. Among the lymphatic tissues, the thymus has been shown to contain the highest amount of SS, suggesting a local functional role of the peptide. We investigated the SS distribution and SS-R expression pattern in the normal human thymus using autoradiography, membrane homogenate binding studies, and RT-PCR. In addition, the effect of SS and octreotide on growth of cultured thymic epithelial cells (TEC) was studied. By autoradiography, binding of [125I-Tyr0]-SS-28 and [125I-Tyr3]-octreotide was detected in all seven thymuses studied. Specific [125I-Tyr3]-octreotide binding was shown on membrane preparations from thymuses, while not from cultured thymocytes. RT-PCR showed the expression of sst1, sst2A and sst3 messenger RNA (mRNA) in the thymic tissue, whereas sst1 and sst2A mRNAs were found in isolated TEC. SS mRNA was present in thymic tissue and in isolated TEC. SS and octreotide significantly inhibited 3H-thymidine incorporation in 3 of 3 and 6 of 6 TEC cultures, respectively. The percent inhibition ranged from 38.8 to 66.8% for SS and from 19.1 to 59.5% for octreotide. In conclusion, SS mRNA and sst1, sst2A, and sst3 mRNAs are expressed in the normal human thymus. Cultured TEC selectively express sst1 and sst2A mRNA and respond in vitro to SS and octreotide administration with an inhibition of cell proliferation. These data suggest a paracrine/autocrine role of SS and its receptors in the regulation of cell growth in thymic microenviron

Cineantropometria morfo-funcional em atletas adolescentes

O objetivo deste trabalho foi a analise das.diferenças ocorridas, na capacidade aeróbica (consumo máximo de oxigênio em 1/min em ml/kg/min), na frequência cardíaca máxima e na frequência cardíaca de recuperação, em um período de onze meses de treinamento e competições de atletismo,, seguidos de um mês de descanso, em relação ao crescimento de atletas adolescentes pós-púberes corredores e saltadores. Foram testados oito atletas do sexo masculino, na idade x-16,8 anos, que estavam realizando um programa de treinamento de atletismo de acordo com suas respectivas modalidades, já em nível competitivo nacional. Foram feitas as medidas antropométricas da estatura, peso, dobras cutâneas (tricipitai, subescapular, suprailíaca e abdominal): a percentual de gordura e a massa magra. A potência máxima aeróbica foi calculada conforme Astrand e Ryhming (1954), em 1/min e ml/kg/min na bicicleta ergométrica, registrando-se o eletrocardiograma de esforço para o estudo da frequência cardíaca máxima e da frequência cardíaca de recuperação no primeiro, quinto e oitavo minutos. O nível de significância fixou-se em 5°o. Nâo houve diferença significativa no consumo máximo de oxigê­ nio em 1/min em ml/kg/min, ou seja manteve-se está­ vel. Em relação às variáveis antropométricas, a estatura aumentou significativamente (de x~ 174,3 cm para x~ 174,9 cm). O peso apresentou diferença significati- - va entre o pré e o pós-treino, de x=62,8 kg para x=64,9 kg. A gordura percentual não apresentou diferença significativa. A massa magra teve um aumento significativo, de x=56,2 kg para x =58,2 kg. A frequência cardíaca máxima e a frequência cardíaca de recuperação no primeiro, quinto e oitavo minutos, não apresentaram diferenças significativas: a queda porcentual da frequência cardíaca, no primeiro minuto de recuperação em relação a máxima atingida foi de 27% no pré e de 19,4% no pós-treino. Não houve correla­ ção significativa entre os valores do delta do consumo máximo de oxigênio em 1/min e em ml/kg/min e os deltas da estatura, do peso, da gordura percentual e da massa magrThe purpose was to analyse, the aerobic capacity (VOpMAX in l/min and l/kg/min), maxinal heart rate and recovery heart rat during and eleven-month period of training, followed by one month of rest in relation to growth of post-pubere adolescent track and field athletes. Eight athletes (male) with an average of 16,8 years for age age were undergoing a track and field training program according to their respective events on a national competitive level. Anthropometric measurements (height and weight, tricipital, subscapular, super-ilical and abdominal skinfolds), maximal aerobic power on the cicloergometer, maximal heart rate, and recovery heart rate. The significant level was established at a 5%. The VO2MAX in l/min and in ml/kg/mih, im pre and post-training period remained the same. 'Concerning growth variables: the height increased significantly: and on the other hand, weight differed significantly (pre post-training); fat percent showed no changes; lean body mass incresead significantly. No difference was observed in maximal hearth rate and recovery hearth rate in the first, fifth and eighth minute. (CAPES, CNPq, EEFUSP)

Heart rate variability and early recurrence of atrial fibrillation after electrical cardioversion

The study evaluated the role of the autonomic nervous system in atrial fibrillation (AF) recurrence

Development of electrospun photocatalytic TiO2-polyamide-12 nanocomposites

Titanium dioxide (TiO2) in different forms such as films, fibers or particles are being extensively studied for removal of contaminants from aquatic environments due to its outstanding photocatalytic activity. This work reports the development of TiO2-polyamide 12 electrospun fiber mats. A systematic study on the influence of electrospun processing parameters on polymer fiber morphology was performed. It was observed that the average fiber diameter is mainly influenced by polymer concentration and average fiber diameters between 404 ± 82 nm and 1442 ± 360 nm were obtained. Polyamide-12 (PA-12) was used as a polymer matrix and electrospun with 0, 10 and 20 wt% of TiO2. It was observed that the filler does not change the average fiber diameter, being similar to that observed for neat PA-12 fibers processed under the same experimental conditions. The TiO2 were particles dispensed not only in the bulk of the polymeric matrix but also on the surface of the fibers, especially for the samples with higher filler contents. Neat and nanocomposite electrospun samples show a hydrophobic behavior and a degree of crystallinity of ~25%. The photocatalytic performance of the processed samples was measured by following the degradation capability of a chosen dye, methylene blue (MB). Results show that the nanocomposite samples have a remarkable photocatalytic activity, especially the one with a higher load of TiO2 particles (20 wt%), with all MB being removed from the solution after 100 min.This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/ UI607/2014, and CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnol ogico e Brazil). The authors also thank funding from “Matepro eOptimizing Materials and Processes”, ref. NORTE- 07-0124-FEDER-000037”, co-funded by the “Programa Operacional Regional do Norte” (ON.2 e O Novo Norte), under the “Quadro de Refer^encia Estrat egico Nacional” (QREN), through the “Fundo Europeu de Desenvolvimento Regional” (FEDER). PM thanks the FCT for the, SFRH/BD/98616/2013 grant. VS and SLM also thank support from the COST Action MP1206 “Electrospun Nano-fibers for bio inspired composite materials and innovative industrial applications”. VS thanks the EIS Faculty at UOW for the starting grant

Zero-bias conductance peak splitting due to multiband effect in tunneling spectroscopy

We study how the multiplicity of the Fermi surface affects the zero-bias peak in conductance spectra of tunneling spectroscopy. As case studies, we consider models for organic superconductors $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$ and (TMTSF)$_2$ClO$_4$. We find that multiplicity of the Fermi surfaces can lead to a splitting of the zero-bias conductance peak (ZBCP). We propose that the presence/absence of the ZBCP splitting is used as a probe to distinguish the pairing symmetry in $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$.Comment: 7 pages, 7 figure

What is the future for nuclear fission technology? A technical opinion from the Guest Editors of VSI NFT series and the Editor of the Journal Nuclear Engineering and Design

The Nuclear Fission Technology (NFT) series of Virtual Special Issues (VSIs) for the Journal Nuclear Engineering and Design (J NED) was proposed in 2023, including the request to potential authors of manuscript to address the following questions: o For how long will (water-cooling based) large size nuclear reactor survive? o Will water-technology based SMRs displace large reactors? o Will non-water-cooling technology SMRs and micro-reactors have an industrial deployment? o Will breeding technology, including thorium exploitation, have due relevance? o Will ‘nuclear infrastructure’ (fuel supply, financial framework, competence by regulators for new designs, waste management, etc.) remain or be sufficiently robust? Several dozen Guest Editors (GEs), i.e., the authors of the present document, managed the activity together with the Editor-in-Chief (EiC) of the journal. More than one thousand scientists contributed 470+ manuscripts, not evenly distributed among the geographical regions of the world and not necessarily addressing directly the bullet-questions, but certainly providing a view of current research being done. Key conclusions are as follows: (a) Large size reactors are necessary for a sustainable and safe exploitation of nuclear fission technology; (b) The burning of 233U (from thorium) and 239Pu (from uranium) is unavoidable, as well as recycling residual uranium currently part of waste; (c) Nuclear infrastructures in countries that currently use, or are entering the use of, fission energy for electricity production need a century planning; (d) The adoption of small reactors for commercial naval propulsion, hydrogen production and desalination is highly recommended

Baryons: What, When and Where?

We review the current state of empirical knowledge of the total budget of baryonic matter in the Universe as observed since the epoch of reionization. Our summary examines on three milestone redshifts since the reionization of H in the IGM, z = 3, 1, and 0, with emphasis on the endpoints. We review the observational techniques used to discover and characterize the phases of baryons. In the spirit of the meeting, the level is aimed at a diverse and non-expert audience and additional attention is given to describe how space missions expected to launch within the next decade will impact this scientific field.Comment: Proceedings Review for "Astrophysics in the Next Decade: JWST and Concurrent Facilities", ed. X. Tielens, 38 pages, 10 color figures. Revised to address comments from the communit