In forensic toxicology, drugs of abuse are routinely analyzed due to legal statute in medical or legal investigation, such as death cases, poisoning cases, and drug misuse, determining potential exposure to controlled substances. Despite the widespread use of blood and urine as matrices for forensic toxicological analysis, the use of hair samples has grown as the limitations associated with this matrix are overcome and new areas of application emerge. Hair provides several advantages over urine and blood, such as the easiness of sample collection and the ability to provide a retrospective analysis of drug consumption. Drug analysis in hair is following a path where less amount of sample has been needed to detect drugs of abuse. Improvement in sample preparation methods and lowering detection limits in instrumental analysis is providing forensic scientists with the tools to use drug analysis with hair as a routine approach in the forensic laboratory. Actually, besides the chronological exposition to a drug, hair may provide information about the day a chemical was used. This should become part of the standard information sent by forensic scientists to criminal investigators and courts. The aim of this review is to summon the extraction procedures used to perform forensic toxicological analysis in hair as well as the major advances in this field once a sample preparation step is critical and takes up most of the total analysis time.

Background Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARS-CoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.

Background Adults are being vaccinated against SARS-CoV-2 worldwide, but the longitudinal protection of these vaccines is uncertain, given the ongoing appearance of SARS-CoV-2 variants. Children remain largely unvaccinated and are susceptible to infection, with studies reporting that they actively transmit the virus even when asymptomatic, thus affecting the community. Methods We investigated if saliva is an effective sample for detecting SARS-CoV-2 RNA and antibodies in children, and associated viral RNA levels to infectivity. For that, we used a saliva-based SARS-CoV-2 RT-qPCR test, preceded or not by RNA extraction, in 85 children aged 10 years and under, admitted to the hospital regardless of COVID-19 symptomatology. Amongst these, 29 (63.0%) presented at least one COVID-19 symptom, 46 (54.1%) were positive for SARS-CoV-2 infection, 28 (32.9%) were under the age of 1, and the mean (SD) age was 3.8 (3.4) years. Saliva samples were collected up to 48 h after a nasopharyngeal swab-RT-qPCR test. Results In children aged 10 years and under, the sensitivity, specificity, and accuracy of saliva-RT-qPCR tests compared to NP swab-RT-qPCR were, respectively, 84.8% (71.8%–92.4%), 100% (91.0%–100%), and 91.8% (84.0%–96.6%) with RNA extraction, and 81.8% (68.0%–90.5%), 100% (91.0%–100%), and 90.4% (82.1%–95.0%) without RNA extraction. Rescue of infectious particles from saliva was limited to CT values below 26. In addition, we found significant IgM positive responses to SARS-CoV-2 in children positive for SARS-CoV-2 by NP swab and negative by saliva compared to other groups, indicating late infection onset (>7–10 days). Conclusions Saliva is a suitable sample type for diagnosing children aged 10 years and under, including infants aged <1 year, even bypassing RNA extraction methods. Importantly, the detected viral RNA levels were significantly above the infectivity threshold in several samples. Further investigation is required to correlate SARS-CoV-2 RNA levels to viral transmission.

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Introduction Aggression is a pervasive condition in human civilisation that sometimes emerge in human actions and consists in physical and verbal actions with the intention of causing harm to others. The term aggression can be divided in two types. Expressive aggression appears by provocation and it is usually driven by anger. Otherwise, instrumental aggression is performed as a premeditated mean to obtain something [ 1 ]. Aggressive behaviour is a complex process that involves the interaction between diverse factors, including genetic and environmental factors. The aim of this study is to give an overview of the several studies that have identified genetic alterations that may influence the behaviour of individuals. In terms of aggression, research is focussed on signalling pathways, especially involving dopamine and serotonin [ 2 ]. Materials and methods Searches were made in the PubMed and B-on online databases. Search terms included “Genetic variants” combined with “Aggression” or “Aggressive behaviour”. The search was limited to articles published on or after the 1 st of January 2000 and in English-language peer-reviewed journal publications. Papers focussed on genetic variants that did not relate to the dopamine and serotonin pathways were excluded. Further literature sources were identified by following up internal citations and references. After articles analysis, 24 studies were considered in this literature review. Results The search for genes involved in impulsivity and aggression traits identified different candidate genes belonging to dopamine and serotonin pathways, of which MAO-A , COMT , SLC6A4 , SLC6A3 , HTR1A , HTR1B , HTR2A , HTR2C , HTR6 , DRD2 , DRD4 , TPH1 and DBH genes [ 3 , 4 ]. Results revealed the presence of 18 variants. The majority of these variants were SNPs, except 5 VNTR and 1 InDel. Discussion and conclusions Some studies found associations between several genetic variants and aggression. However, in many others such associations were unclear [ 2 , 3 ]. The fusion of genetics and psychology into these studies is essential. Notwithstanding, this literature review showed that all previous studies applied a limited psychological assessment of the subjects, leading to partial characterisation of the problem [ 4 ]. As such, it is critical to get a deeper insight into the association between aggressive behav...