Search Results

You are looking at 1 - 4 of 4 items for

  • Author or Editor: B. Castro x
Clear All Modify Search

In 2005, a severe drought occurred in Portugal, with several reservoirs becoming dry in the southern region. A set of 20 Portuguese water bodies were analysed through denaturing gradient gel electrophoresis (16SrDNA-DGGE) and DNA sequencing to assess its bacterioplankton diversity under these particular conditions. Environmental parameters were determined to assess the trophic conditions of each water body. Most water bodies fell into the meso-to eutrophic and hypereutrophic state. In general, the levels for conductivity, pH and total suspended solids were higher than the average data from previous years. Dominant phylotypes belonged to Cyanobacteria, Actinobacteria Alphaproteobacteria, Betaproteobacteria and Bacteroidetes groups. Despite the geographic distance, common phylotypes could be recorded among water bodies. Bacteroidetes dominated at Sousa River and were related to high nutrient levels. Cyanobacteria dominated at Alentejo reservoirs and correlated with higher conductivity values. However, Actinobacteria showed ubiquitous phylotypes throughout several samples, suggesting its persistence over geographically distant water bodies. This study showed a clear deterioration of water quality, from a physico-chemical point of view; furthermore, dominance of Cyanobacteria and Actinobacteria in reservoirs used for drinking water supply were also detected, which may become a concerning issue. However, the most severe bacterial community composition variations between summer 2005 and others were mainly related to higher water residence times. Thus, along with the expected intensification of drought episodes, with severe effects particularly in Southern Europe, it is clearly predictable an intensification in risks for water quality maintenance and even Public Health.

Restricted access

Abstract

Background and aims

Compulsive Sexual Behavior Disorder (CSBD) is characterized by a persistent failure to control intense and recurrent sexual impulses, urges, and/or thoughts, resulting in repetitive sexual behavior that causes a marked impairment in important areas of functioning. Despite its recent inclusion in the forthcoming ICD-11, concerns regarding its assessment, diagnosis, prevalence or clinical characteristics remain. The purpose of this study was to identify participants displaying CSBD through a novel data-driven approach in two independent samples and outline their sociodemographic, sexual, and clinical profile.

Methods

Sample 1 included 1,581 university students (females = 56.9%; M age = 20.58) whereas sample 2 comprised 1,318 community members (females = 43.6%; M age = 32.37). First, we developed a new composite index to assess the whole range of CSBD symptoms based on three previously validated scales. Based on this new composite index, we subsequently identified individuals with CSBD through a cluster analytic approach.

Results

The estimated occurrence of CSBD was 10.12% in sample 1 and 7.81% in sample 2. Participants with CSBD were mostly heterosexual males, younger than respondents without CSBD, reported higher levels of sexual sensation seeking and erotophilia, an increased offline and especially online sexual activity, more depressive and anxious symptoms, and poorer self-esteem.

Conclusions

This research provides further evidence on the occurrence of CSBD based on an alternative data-driven approach, as well as a detailed and nuanced description of the sociodemographic, sexual, and clinical profile of adults with this condition. Clinical implications derived from these findings are discussed in detail.

Open access
Journal of Thermal Analysis and Calorimetry
Authors: Késia K. V. Castro, Ana A. D. Paulino, Edjane F. B. Silva, Thiago Chellappa, Maria B. D. L. Lago, Valter J. Fernandes Jr. and Antonio S. Araujo

Abstract

Thermogravimetry (TG) was used in this study to evaluate thermal and catalytic pyrolysis of Atmospheric Petroleum Residue (ATR) which can be found in the state of Rio Grande do Norte/Brazil, after a process of atmospheric distillation of petroleum. The utilized sample in the process of catalytic pyrolysis was Al-MCM-41, a mesoporous material. The procedures for obtaining the thermogravimetric curves were performed in a thermobalance with heating rates of 5, 10, and 20 °C min−1. From TG, the activation energy was determined using the Flynn–Wall kinetic method, which decreased from 161 kJ mol−1, for the pure ATR, to 71 kJ mol−1, in the presence of the Al-MCM-41, showing the efficiency of the catalyst in the pyrolysis of Atmospheric Petroleum Residue.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: C. M. Novais, P. B. Pujatti, M. A. S. Castro, M. A. Soares, M. E. De Lima, C. Simal and R. Gouv?a dos Santos

Summary  

Crotoxin (Crtx) is the main toxin of South American rattlesnake (Crotalus durissus terrificus) venom. Research on antitumoral drugs has demonstrated the potential use of Crtx as tumour reducing agent. Tissue distribution studies are very important for clinical use and 99mTc-labeling is a very convenient method for studies related to biodistribution. The aim of the present study was to label Crtx with 99mTc keeping its biological activity for use in biodistribution and binding studies. High labeling yield was obtained using stannous chloride and sodium borohydride. Results demonstrated that biological activity of 99mTc-Crtx was preserved and confirmed kidneys as the target organ. Biological activities of unlabeled and 99mTc-labeled Crtx were evaluated after labeling. 99mTc-Crtx can be a useful tool for imaging and binding studies.

Restricted access