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排序方式: 共有536条查询结果,搜索用时 31 毫秒
191.
Concheiro M Simões SM Quintela O de Castro A Dias MJ Cruz A López-Rivadulla M 《Forensic science international》2007,171(1):44-51
A fast method was designed for the simultaneous determination of amphetamine (A), methamphetamine (MA), PMA, MDA, MDMA, MDEA and MBDB in urine. The drugs were analysed by LC (ESI)-MS/MS, after a simple liquid-liquid extraction in the presence of the deuterated analogues. Reverse phase separation on an Atlantis dC18 Intelligent Speed column was achieved in less than 4 min under gradient conditions, and the total run time was 8 min. The method was fully validated, including linearity (1-1000 ng/mL for A, MDMA, MDEA and MBDB; 2-1000 ng/mL for MDA and PMA; 1-200 ng/mL for MA; r2>0.99 for all compounds), recovery (>80%), within-day and between-day precision and accuracy (CV and MRE<12.7% for intermediate level and ULOQ, and <17.2% for LLOQ), limit of detection (0.2 ng/mL for MDMA, MDEA and MBDB; 0.5 ng/mL for A, MA and PMA; 1 ng/mL for MDA) and quantitation (1 ng/mL for A, MA, MDMA, MDEA and MBDB; 2 ng/mL for MDA and PMA) and relative ion intensities. No matrix effect was observed. The procedure proved to be sensitive, specific and rapid, and was applied to real forensic cases. 相似文献
192.
Establishing a person's identity can be a very difficult process. Dental, fingerprint and DNA comparisons are probably the most common techniques used in this context, allowing fast and secure identification processes. However, since they cannot always be used, sometimes it is necessary to apply different and less known techniques. In this paper, the authors describe two unusual techniques: cheiloscopy and palatoscopy. It is known that due to their special features, both lip grooves and palatal rugae can be used successfully in human identification. This paper reviews the techniques of cheiloscopy and palatoscopy, and describes the different classifications and their advantages and limitations. 相似文献
193.
Montesino M Salas A Crespillo M Albarrán C Alonso A Alvarez-Iglesias V Cano JA Carvalho M Corach D Cruz C Di Lonardo A Espinheira R Farfán MJ Filippini S García-Hirschfeld J Hernández A Lima G López-Cubría CM López-Soto M Pagano S Paredes M Pinheiro MF Rodríguez-Monge AM Sala A Sóñora S Sumita DR Vide MC Whittle MR Zurita A Prieto L 《Forensic science international》2007,168(1):42-56
The mitochondrial DNA (mtDNA) working group of the GEP-ISFG (Spanish and Portuguese Group of the International Society for Forensic Genetics) carried out an inter-laboratory exercise consisting of the analysis of mtDNA sequencing patterns in mixed stains (saliva/semen and blood/semen). Mixtures were prepared with saliva or blood from a female donor and three different semen dilutions (pure, 1:10 and 1:20) in order to simulate forensic casework. All labs extracted the DNA by preferential lysis and amplified and sequenced the first mtDNA hypervariable region (HVS-I). Autosomal and Y-STR markers were also analysed in order to compare nuclear and mitochondrial results from the same DNA extracts. A mixed stain prepared using semen from a vasectomized individual was also analysed. The results were reasonably consistent among labs for the first fractions but not for the second ones, for which some laboratories reported contamination problems. In the first fractions, both the female and male haplotypes were generally detected in those samples prepared with undiluted semen. In contrast, most of the mixtures prepared with diluted semen only yielded the female haplotype, suggesting that the mtDNA copy number per cell is smaller in semen than in saliva or blood. Although the detection level of the male component decreased in accordance with the degree of semen dilution, it was found that the loss of signal was not consistently uniform throughout each electropherogram. Moreover, differences between mixtures prepared from different donors and different body fluids were also observed. We conclude that the particular characteristics of each mixed stain can deeply influence the interpretation of the mtDNA evidence in forensic mixtures (leading in some cases to false exclusions). In this sense, the implementation of preliminary tests with the aim of identifying the fluids involved in the mixture is an essential tool. In addition, in order to prevent incorrect conclusions in the interpretation of electropherograms we strongly recommend: (i) the use of additional sequencing primers to confirm the sequencing results and (ii) interpreting the results to the light of the phylogenetic perspective. 相似文献
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195.
Armanda P. M. Matos Cristina C. Vieira João Amado Teresa Pessoa Maria José D. Martins 《Journal of school violence》2018,17(1):123-137
This study examined the extent and nature of cyberbullying in 23 Portuguese schools. A sample of 3,525 sixth-, eighth-, and eleventh-grade students completed a self-response questionnaire assessing their perceptions and experiences of cyberbullying. The findings showed that 7.6% of students have been victimized, and 3.9% have bullied others at least once over the last year. The incidences of victimization were higher for females and for the older students. In contrast, more boys reported having bullied others in the eleventh grade. The most frequent medium of cyberbullying was via websites, whilst sending offensive messages was the most widely reported type of behavior. Telling someone about cyberbullying is among the most frequent coping strategies used by cybervictims, who usually chose to tell their friends rather than adults. Implications of these findings for students, schools, and parents are discussed. 相似文献
196.
High‐Resolution Melting (HRM) of Hypervariable Mitochondrial DNA Regions for Forensic Science
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Alípio dos Santos Rocha M.Sc. Isis Salviano Soares de Amorim M.Sc. Tatiana de Almeida Simão Ph.D. Adenilson de Souza da Fonseca Ph.D. Rodrigo Grazinoli Garrido Ph.D. Andre Luiz Mencalha Ph.D. 《Journal of forensic sciences》2018,63(2):536-540
Forensic strategies commonly are proceeding by analysis of short tandem repeats (STRs); however, new additional strategies have been proposed for forensic science. Thus, this article standardized the high‐resolution melting (HRM) of DNA for forensic analyzes. For HRM, mitochondrial DNA (mtDNA) from eight individuals were extracted from mucosa swabs by DNAzol reagent, samples were amplified by PCR and submitted to HRM analysis to identify differences in hypervariable (HV) regions I and II. To confirm HRM, all PCR products were DNA sequencing. The data suggest that is possible discriminate DNA from different samples by HRM curves. Also, uncommon dual‐dissociation was identified in a single PCR product, increasing HRM analyzes by evaluation of melting peaks. Thus, HRM is accurate and useful to screening small differences in HVI and HVII regions from mtDNA and increase the efficiency of laboratory routines based on forensic genetics. 相似文献
197.
Júlia de A. Leite Marcos V.L. de Oliveira Raphael Conti Warley de S. Borges Thalles R. Rosa Paulo R. Filgueiras Valdemar Lacerda Wanderson Romão Álvaro C. Neto 《Science & justice》2018,58(5):355-365
Marijuana, a drug derived from the Cannabis sativa L. plant, is the world's most consumed illicit drug. In this paper, a total of 156 marijuana samples seized in the state of Espírito Santo (ES), Brazil were studied and analysed by proton nuclear magnetic resonance (1H NMR) spectroscopy to identify the major cannabinoids present. A crude extract of all samples was purified using high performance liquid chromatography so that these compounds could serve as reference substances. Nine fractions were obtained and analysed by 1H NMR and gas chromatography–mass spectrometry (GC–MS), with five presented cannabinoids. ?9-THC (Δ9-trans-tetrahydrocannabinol), ?9-THCA (?9-tetrahydrocannabinolic acid), ?8-THC (?8-tetrahydrocannabinol), 11-hydroxycannabinol, CBV (cannabivarin), and CBN (cannabinol) were found, and their chemical structures were confirmed by GC–MS. The latter compound was obtained with high purity (≈100%), while the others were obtained as less complex mixtures with purity higher than 75% (except for Δ8-THC). Principal component analysis (PCA) was used on the 1H NMR spectra of the 156 samples, and it was found that the samples were grouped according to the months, differentiating into two groups (from July 2014 to January 2015 and from February 2015 to July 2015), where non-grouping was observed from four macro-regions of the ES state (North, Central, Metropolitan, and South). The chemical profile of the seized samples was correlated to the 1H NMR spectrum of an isolated CBN sub-fraction, in which the group formed by samples seized in the year 2015 presented lower CBN content in the chemical composition. From the PCA score plot, two groups of samples were confirmed using the partial least squares discriminant analysis and orthogonal projections to latent structures classification methods. 相似文献
198.
The migration system in the Persian (Arabian) Gulf is among the largest such systems in the world. This article identifies the major interacting elements of this system, which primarily includes countries in South Asia and the Middle East, and discusses its generating forces and developments over the past five and a half decades. Departing from panel data from the World Bank and the UN’s population database, which hitherto have been largely under-analysed, we investigate the dynamics of migrations in the period 1960–2013. The panel data are combined with cross-sectional outlooks of contemporary trends and are related to political and economic developments in the region. It is suggested that the patterns of migrations in the Gulf may be explained with reference to the economic, political and demographic idiosyncrasies of the system, and to the migration policies of the GCC countries. In short, the key drivers of GCC migration patterns include: (1) socio-economic realities, in particular income differentials between migrant senders and migrant receivers as well as impressive growth rates in the Gulf region; (2) historical, cultural and institutional proximity among the constituent states in the system; and (3) the particularities of the Gulf states’ liberal labour-migrant regimes, which contrast starkly with their restrictive refugee and naturalisation policies. 相似文献
199.
200.
Paulo Vieira-Pinto JoséIgnacio Muñoz-Barús Tiago Taveira-Gomes Maria João Vidal-Alves Teresa Magalhães 《法庭科学研究(英文)》2022,7(1):53
Intimate partner violence(IPV)is simultaneously assumed as a serious crime and a major public health issue,having recurrences as one of its main characteristics and,consequently,re-entries of some alleged offenders in the criminal justice system(CJS).The main goal of this study is to assess if in cases of female victims of IPV,violence decreases after the first entry of the alleged offender in the CJS.A retrospective study was performed based on the analysis of police reports of alleged cases of IPV during a 4-year period.The final sample(n=1488)was divided into two groups according to the number of entries in the CJS(single or multiple)followed by a comparative approach.Results suggest that violence decreases after the first entry of alleged offenders in the CJS.Re-entries were found in only 15.5%of the cases but they were accountable for 3.3 times more crimes on average.Besides,victims of recidivism presented more injuries and required more medical care.Thus,a small group of alleged offenders seems to be more violent and accountable for most of the IPV crimes registered in the CJS suggesting that regardless of legal sanctions aiming to deter violence,these measures may not be enough for a certain group of offenders.This study sustains the need for a predictive model to quantify the risk of repeated IPV cases within the Portuguese population. 相似文献