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1.
Small ; 19(43): e2300671, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37381636

RESUMO

Artificially augmented photosynthesis in nano-bionic plants requires tunable nano-antenna structures with physiochemical and optoelectronic properties, as well as unique light conversion capabilities. The use of nanomaterials to promote light capture across photosystems, primarily by carbon dots, has shown promising results in enhancing photosynthesis through tunable uptake, translocation, and biocompatibility. Carbon dots possess the ability to perform both down and up-light conversions, making them effective light promoters for harnessing solar energy beyond visible light wavelengths.This review presents and discusses the recent progress in fabrication, chemistry, and morphology, as well as other properties such as photoluminescence and energy conversion efficiency of nano-antennas based on carbon dots. The performance of artificially boosted photosynthesis is discussed and then correlated with the conversion properties of carbon dots and how they are applied to plant models. The challenges related to the nanomaterial delivery and the performance evaluation practices in modified photosystems, consideration of the reliability of this approach, and the potential avenues for performance improvements through other types of nano-antennas based on alternative nanomaterials are also critically evaluated. It is anticipated that this review will stimulate more high-quality research in plant nano-bionics and provide avenues to enhance photosynthesis for future agricultural applications.


Assuntos
Carbono , Fotossíntese , Carbono/química , Reprodutibilidade dos Testes , Luz , Plantas
2.
Am J Physiol Regul Integr Comp Physiol ; 315(2): R380-R396, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29668323

RESUMO

Selenoprotein S (Seps1) is an endoplasmic reticulum (ER) resident antioxidant implicated in ER stress and inflammation. In human vastus lateralis and mouse hindlimb muscles, Seps1 localization and expression were fiber-type specific. In male Seps1+/- heterozygous mice, spontaneous physical activity was reduced compared with wild-type littermates ( d = 1.10, P = 0.029). A similar trend was also observed in Seps1-/- knockout mice ( d = 1.12, P = 0.051). Whole body metabolism, body composition, extensor digitorum longus (EDL), and soleus mass and myofiber diameter were unaffected by genotype. However, in isolated fast EDL muscles from Seps1-/- knockout mice, the force frequency curve (FFC; 1-120 Hz) was shifted downward versus EDL muscles from wild-type littermates ( d = 0.55, P = 0.002), suggestive of reduced strength. During 4 min of intermittent, submaximal (60 Hz) stimulation, the genetic deletion or reduction of Seps1 decreased EDL force production ( d = 0.52, P < 0.001). Furthermore, at the start of the intermittent stimulation protocol, when compared with the 60-Hz stimulation of the FFC, EDL muscles from Seps1-/- knockout or Seps1+/- heterozygous mice produced 10% less force than those from wild-type littermates ( d = 0.31, P < 0.001 and d = 0.39, P = 0.015). This functional impairment was associated with reduced mRNA transcript abundance of thioredoxin-1 ( Trx1), thioredoxin interacting protein ( Txnip), and the ER stress markers Chop and Grp94, whereas, in slow soleus muscles, Seps1 deletion did not compromise contractile function and Trx1 ( d = 1.38, P = 0.012) and Txnip ( d = 1.27, P = 0.025) gene expression was increased. Seps1 is a novel regulator of contractile function and cellular stress responses in fast-twitch muscles.


Assuntos
Retículo Endoplasmático/enzimologia , Proteínas de Membrana/deficiência , Contração Muscular , Fibras Musculares de Contração Rápida/enzimologia , Força Muscular , Selenoproteínas/deficiência , Adulto , Animais , Composição Corporal , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Estimulação Elétrica , Estresse do Retículo Endoplasmático , Membro Posterior , Humanos , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atividade Motora , Fibras Musculares de Contração Lenta/enzimologia , Selenoproteínas/genética , Selenoproteínas/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo , Adulto Jovem
3.
Mycorrhiza ; 26(8): 919-930, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27485855

RESUMO

Arbuscular mycorrhiza is a symbiotic association formed between plant roots and soil borne fungi that alter and at times improve the production of secondary metabolites. Detailed information is available on mycorrhizal development and its influence on plants grown under various edapho-climatic conditions, however, very little is known about their influence on transformed roots that are rich reserves of secondary metabolites. This raises the question of how mycorrhizal colonization progresses in transformed roots grown in vitro and whether the mycorrhizal fungus presence influences the production of secondary metabolites. To fully understand mycorrhizal ontogenesis and its effect on root morphology, root biomass, total phenolics, rosmarinic acid, caffeic acid and antioxidant production under in vitro conditions, a co-culture was developed between three Agrobacterium rhizogenes-derived, elite-transformed root lines of Ocimum basilicum and Rhizophagus irregularis. We found that mycorrhizal ontogenesis in transformed roots was similar to mycorrhizal roots obtained from an in planta system. Mycorrhizal establishment was also found to be transformed root line-specific. Colonization of transformed roots increased the concentration of rosmarinic acid, caffeic acid and antioxidant production while no effect was observed on root morphological traits and biomass. Enhancement of total phenolics and rosmarinic acid in the three mycorrhizal transformed root lines was found to be transformed root line-specific and age dependent. We reveal the potential of R. irregularis as a biotic elicitor in vitro and propose its incorporation into commercial in vitro secondary metabolite production via transformed roots.


Assuntos
Cinamatos/metabolismo , Depsídeos/metabolismo , Glomeromycota/fisiologia , Micorrizas/fisiologia , Ocimum basilicum/microbiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Técnicas de Cocultura , Glomeromycota/ultraestrutura , Medições Luminescentes , Raízes de Plantas/ultraestrutura , Técnicas de Cultura de Tecidos , Ácido Rosmarínico
4.
Plant Foods Hum Nutr ; 71(1): 72-80, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26803763

RESUMO

Ocimum basilicum, a member of the family Lamiaceae, is a rich source of polyphenolics that have antioxidant properties. The present study describes the development and application of an online HPLC-coupled acidic potassium permanganate chemiluminescence assay for the qualitative and quantitative assessment of antioxidants in three cultivars of O. basilicum grown under greenhouse conditions. The chemiluminescence based assay was found to be a sensitive and efficient method for assessment of total and individual compound antioxidant potential. Leaves, flowers and roots were found to be rich reserves of the antioxidant compounds which showed intense chemiluminescence signals. The polyphenolics such as rosmarinic, chicoric, caffeic, p-coumaric, m-coumaric and ferulic acids showed antioxidant activity. Further, rosmarinic acid was found to be the major antioxidant component in water-ethanol extracts. The highest levels of rosmarinic acid was found in the leaves and roots of cultivars "holy green" (14.37; 11.52 mM/100 g DW respectively) followed by "red rubin" (10.02; 10.75 mM/100 g DW respectively) and "subja" (6.59; 4.97 mM/100 g DW respectively). The sensitivity, efficiency and ease of use of the chemiluminescence based assay should now be considered for its use as a primary method for the identification and quantification of antioxidants in plant extracts.


Assuntos
Antioxidantes/análise , Cinamatos/análise , Depsídeos/análise , Ocimum basilicum/química , Extratos Vegetais/química , Polifenóis/análise , Permanganato de Potássio/química , Antioxidantes/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cinamatos/isolamento & purificação , Depsídeos/isolamento & purificação , Flores/química , Concentração de Íons de Hidrogênio , Luminescência , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Raízes de Plantas/química , Polifenóis/isolamento & purificação , Sensibilidade e Especificidade , Ácido Rosmarínico
5.
J Sep Sci ; 38(10): 1642-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25735884

RESUMO

This paper explores the analytical figures of merit of two-dimensional high-performance liquid chromatography for the separation of antioxidant standards. The cumulative two-dimensional high-performance liquid chromatography peak area was calculated for 11 antioxidants by two different methods--the areas reported by the control software and by fitting the data with a Gaussian model; these methods were evaluated for precision and sensitivity. Both methods demonstrated excellent precision in regards to retention time in the second dimension (%RSD below 1.16%) and cumulative second dimension peak area (%RSD below 3.73% from the instrument software and 5.87% for the Gaussian method). Combining areas reported by the high-performance liquid chromatographic control software displayed superior limits of detection, in the order of 1 × 10(-6) M, almost an order of magnitude lower than the Gaussian method for some analytes. The introduction of the countergradient eliminated the strong solvent mismatch between dimensions, leading to a much improved peak shape and better detection limits for quantification.

6.
J Sep Sci ; 38(12): 2024-32, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25845561

RESUMO

Widely known for its recreational use, the cannabis plant also has the potential to act as an antibacterial agent in the medicinal field. The analysis of cannabis plants/products in both pharmacological and forensic studies often requires the separation of compounds of interest and/or accurate identification of the whole cannabinoid profile. In order to provide a complete separation and detection of cannabinoids, a new two-dimensional liquid chromatography method has been developed using acidic potassium permanganate chemiluminescence detection, which has been shown to be selective for cannabinoids. This was carried out using a Luna 100 Å CN column and a Poroshell 120 EC-C18 column in the first and second dimensions, respectively. The method has utilized a large amount of the available separation space with a spreading angle of 48.4° and a correlation of 0.66 allowing the determination of more than 120 constituents and mass spectral identification of ten cannabinoids in a single analytical run. The method has the potential to improve research involved in the characterization of sensitive, complex matrices.


Assuntos
Canabinoides/química , Cannabis/química , Luminescência , Permanganato de Potássio/química , Canabinoides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Espectrometria de Massas , Folhas de Planta/química , Raízes de Plantas/química , Solventes/química
7.
Anal Bioanal Chem ; 406(23): 5669-76, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24317518

RESUMO

High-performance liquid chromatography with chemiluminescence detection based on the reaction with acidic potassium permanganate and formaldehyde was explored for the determination of neurotransmitters and their metabolites. The neurotransmitters norepinephrine and dopamine were quantified in the left and right hemispheres of rat hippocampus, nucleus accumbens and prefrontal cortex, and the metabolites vanillylmandelic acid, 3,4-dihydrophenylacetic acid, 5-hydroxyindole-3-acetic acid and homovanillic acid were identified in human urine. Under optimised chemiluminescence reagent conditions, the limits of detection for these analytes ranged from 2.5 × 10(-8) to 2.5 × 10(-7) M. For the determination of neurotransmitter metabolites in urine, a two-dimensional high-performance liquid chromatography (2D-HPLC) separation operated in heart-cutting mode was developed to overcome the peak capacity limitations of the one-dimensional separation. This approach provided the greater separation power of 2D-HPLC with analysis times comparable to conventional one-dimensional separations.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Dopamina/análise , Medições Luminescentes/métodos , Neurotransmissores/análise , Norepinefrina/análise , Animais , Cromatografia Líquida de Alta Pressão/instrumentação , Dopamina/metabolismo , Dopamina/urina , Humanos , Medições Luminescentes/instrumentação , Neurotransmissores/metabolismo , Neurotransmissores/urina , Norepinefrina/metabolismo , Norepinefrina/urina , Permanganato de Potássio/química , Ratos
8.
J Sep Sci ; 37(15): 1937-43, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24824418

RESUMO

The synthesis and chromatographic behavior of an analytical size mixed-mode bonded silica monolith was investigated. The monolith was functionalized by an in situ modification process of a bare silica rod with chloro(3-cyanopropyl)dimethyl silane and chlorodimethyl propyl phenyl silane solutions. These ligands were selected in order to combine both resonance and nonresonance π-type bonding within a single separation environment. Selectivity studies were undertaken using n-alkyl benzenes and polycyclic aromatic hydrocarbons in aqueous methanol and acetonitrile mobile phases to assess the methylene and aromatic selectivities of the column. The results fit with the linear solvent strength theory suggesting excellent selectivity of the column was achieved. Comparison studies were performed on monolithic columns that were functionalized separately with cyano and phenyl ligands, suggesting highly conjugated molecules were able to successfully exploit both of the π-type selectivities afforded by the two different ligands on the mixed-mode column.

9.
Forensic Sci Int ; 360: 112062, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38781837

RESUMO

The use of controlled precursors for reaction optimisation is not always practical. One approach to limiting the use of controlled substances is to instead use 'model compounds'. Herein, two model compounds resembling norephedrine and ephedrine were selected based on their (i) structural similarity (i.e., presence of key functional groups) and (ii) availability from multiple suppliers without restriction. Model compounds 2-amino-1-phenylethanol and 2-(methylamino)-1-phenylethanol (halostachine), were compared to norephedrine and pseudoephedrine by firstly subjecting them to transformations known in the synthesis of amphetamines, and secondly, comparing the compounds using colourimetric spot tests, FTIR and NMR.


Assuntos
Anfetaminas , Estimulantes do Sistema Nervoso Central , Espectroscopia de Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier , Anfetaminas/química , Estimulantes do Sistema Nervoso Central/química , Humanos , Efedrina/química , Colorimetria , Fenilpropanolamina/química , Pseudoefedrina/química , Modelos Químicos
10.
Forensic Sci Int ; 360: 112046, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38718526

RESUMO

Research into the recovery of DNA from illicit drug samples has shown it is possible to get forensically useful profiles from such substrates. However, it is not yet known if the different physical states that drugs can be found in influences the quantity and quality of DNA that can be recovered or what is the best sampling method to adopt for powdered samples. This research used acetaminophen in four different states - large crystalline, powder, in solution, or residue - to determine the efficacy of current DNA technology in recovery and analysis of the resulting sample. Five replicates of each were prepared. Human blood was deposited on or mixed with the drug and left for 1 hour. The surface of the drug was sampled by wet/dry swabbing (where appropriate), or the entire sample was deposited in a tube, and the DNA then extracted using DNA-IQ™. The amount of DNA recovered (ng), degradation index, number of PCR cycles (Ct) required for the IPC to reach threshold, number of alleles in the DNA profile and average peak height (APH) were assessed. All samples, irrespective of the physical state they were collected from, returned full DNA profiles that corresponded to the DNA profile of the blood donor, with no degradation or inhibition detected. It was also found the wet/dry swabbing method returned higher levels of DNA than inclusion of the entire sample into the tube for powdered acetaminophen and the appropriate method to use will be dependent on casework circumstances. The findings of this research further develops our understanding of the recovery of DNA from drugs, and supports the need for further investigation to understand under what conditions DNA can be recovered from illicit substances.


Assuntos
Acetaminofen , Impressões Digitais de DNA , DNA , Reação em Cadeia da Polimerase , Manejo de Espécimes , Acetaminofen/sangue , Humanos , DNA/isolamento & purificação , Manejo de Espécimes/métodos , Impressões Digitais de DNA/métodos , Pós , Repetições de Microssatélites , Analgésicos não Narcóticos , Degradação Necrótica do DNA
11.
J Forensic Sci ; 69(3): 1061-1068, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38415957

RESUMO

An investigation into whether the addition of a commonly used anti-coagulant agent like ethylenediaminetetraacetic acid (EDTA) has an impact on the adhesion potential of blood to non-porous substrates was conducted. Two non-porous substrates (aluminum and polypropylene) exhibiting six different surface roughness categories (R1-R6) were used as test substrates upon which either whole blood or blood treated with EDTA was deposited. Samples were exposed to different drying periods (24 hours, 48 hours, and 1 week) before undergoing a tapping agitation experiment in order to evaluate the adhesion to the surface. Clear differences in adhesion potential were observed between whole blood and blood treated with EDTA. Blood treated with EDTA displayed a stronger adhesion strength to aluminum after a drying time of 24 h pre-agitation, while whole blood presented with a stronger adhesion strength at the drying time of 48 h and 1 week. Both EDTA-treated and EDTA-untreated blood was shown to dislodge less easily on polypropylene with the only difference observed on smooth surfaces (0.51-1.50 µm surface roughness). Thus, when conducting transfer studies using smooth hydrophobic substrates like polypropylene or considering the likelihood of transfer given specific case scenarios, differences in adhesion strength of blood due to hydrophobic substrate characteristics and a decreased surface area need to be considered. Overall, whole blood displayed a better adhesion strength to aluminum, emphasizing that indirect transfer probability experiments using EDTA blood on substrates like aluminum should take an increased dislodgment tendency into account in their transfer estimations.


Assuntos
Alumínio , Anticoagulantes , Ácido Edético , Polipropilenos , Propriedades de Superfície , Ácido Edético/farmacologia , Humanos , Anticoagulantes/farmacologia , Adesividade , Manchas de Sangue , Sangue , Interações Hidrofóbicas e Hidrofílicas
12.
Forensic Sci Int ; 354: 111914, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38154427

RESUMO

A comprehensive investigation into the impact of the physical and chemical variables of a substrate on the deposition was conducted to aid in the estimation of the subsequent transfer probabilities of blood and semen. The study focussed on surface roughness, topography, surface free energy (SFE), wettability, and the capacity for protein adsorption. Conjointly, evaluations of the physical and chemical characteristics of blood and seminal deposits were conducted, to assess the fluid dynamics of these non-Newtonian fluids and their adhesion potential to aluminium and polypropylene. A linear range of surface roughness parameters (0.5 - 3.5 µm) were assessed for their impact on the deposit deposition spread and adhesion height, to gather insight into the change in fluid dynamics of non-Newtonian fluids. Blood has shown to produce a uniform adhesion coverage on aluminium across all roughness categories while blood deposited on polypropylene exhibited a strong hydrophobic response from a surface roughness of 2.0 µm and beyond. Interestingly, the deposition height of blood resulted in near identical values, whether deposited onto the hydrophobic polypropylene or the hydrophilic aluminium substrate, illustrating the potential influence of a heightened fibrinogen adsorption effect. Semen deposited on aluminium resulted in concentrated localised deposition regions after reaching a surface roughness of 2.0 µm, highlighting the development of crystal formations afforded by the sodium ion concentration in the seminal fluid. The semen deposited on polypropylene conformed to the substrate contours producing a deposition film that was smoother than the substrate itself, underlining the effects of thixotropic fluid dynamics. Variables identified here establish the complexity observed for non-Newtonian fluids, and the effect protein adsorption may have on the deposition behaviour of blood and seminal deposits and inform questions in relation to the adhesion strength of said deposits and their ability to dislodge (becoming detached upon the application of an external force) from the substrate surface during a potential transfer event.


Assuntos
Líquidos Corporais , Polipropilenos , Propriedades de Superfície , Polipropilenos/análise , Alumínio/análise , Molhabilidade , Líquidos Corporais/química
13.
Forensic Sci Int ; 356: 111951, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38301431

RESUMO

This study assessed the level of nucleic acid persistence on the substrate pre-, and post-swabbing, in order to assess whether biological materials (touch, saliva, semen, and blood) are collected differently depending on the substrate characteristics. A total of 48 samples per deposit and substrate variety (n = 384) were assessed by tracking the persistence of nucleic acid using Diamond™ Nucleic Acid Dye (DD) staining and Polilight photography. The number of DD nucleic acid fluorescent complexes formed post-staining were counted (fluorescent count) and in conjunction with the fluorescence signal intensity (DD nucleic acid complex accumulation) used to estimate the level of nucleic acid persistence on substrates. Touch deposits have shown to be the most persistent deposit with strong adhesion capabilities on both substrate verities. Saliva displayed a higher persistence than semen and/or blood. Semen displayed a high collection efficiency as well as a high fluorescence signal intensity. Blood displayed a low persistence on both substrates with a superior collection efficiency that may also indicate a higher probability to become dislodged from surfaces given a particular activity. Our research has shown that the persistence and recovery of biological deposits is not only measurable but more importantly, may have the potential to be estimated, as such, may build an understanding that can provide valuable guidance for collection efficiency evaluations, and the assessing of the probability of particular profiles, given alternate propositions of means of transfer occurring.


Assuntos
Impressões Digitais de DNA , Ácidos Nucleicos , DNA , Corantes , Tato
14.
J Sep Sci ; 36(21-22): 3503-10, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24039071

RESUMO

Two multidimensional HPLC separations of an Australian red wine are presented, >70% of the available separation space was used. A porous graphitic carbon (PGC) stationary phase was used as the first dimension in both separations with both RP core-shell and hydrophilic interaction chromatography fully porous columns used separately in the second dimension. To overcome peak analysis problems caused by signal noise and low detection limits, the data were pre-processed with penalised least-squares smoothing. The PGC × RP combination separated 85 peaks with a spreading angle of 71° and the PGC × hydrophilic interaction chromatography separated 207 peaks with a spreading angle of 80°. Both 2D-HPLC steps were completed in 76 min using a comprehensive stop-and-go approach. A smoothing step was added to peak-picking processes and was able to greatly reduce the number of false peaks present due to noise in the chromatograms. The required thresholds were not able to ignore the noise because of the small magnitude of the peaks; 1874 peaks were located in the non-smoothed PGC × RP separation that reduced to 227 peaks after smoothing was included.


Assuntos
Algoritmos , Cromatografia Líquida de Alta Pressão/métodos , Vinho/análise , Carbono/química
15.
Biotechnol Adv ; 62: 108072, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36464145

RESUMO

Several research studies have shown that lichens are productive organisms for the synthesis of a broad range of secondary metabolites. Lichens are a self-sustainable stable microbial ecosystem comprising an exhabitant fungal partner (mycobiont) and at least one or more photosynthetic partners (photobiont). The successful symbiosis is responsible for their persistence throughout time and allows all the partners (holobionts) to thrive in many extreme habitats, where without the synergistic relationship they would be rare or non-existent. The ability to survive in harsh conditions can be directly correlated with the production of some unique metabolites. Despite the potential applications, these unique metabolites have been underutilised by pharmaceutical and agrochemical industries due to their slow growth, low biomass availability and technical challenges involved in their artificial cultivation. However, recent development of biotechnological tools such as molecular phylogenetics, modern tissue culture techniques, metabolomics and molecular engineering are opening up a new opportunity to exploit these compounds within the lichen holobiome for industrial applications. This review also highlights the recent advances in culturing the symbionts and the computational and molecular genetics approaches of lichen gene regulation recognized for the enhanced production of target metabolites. The recent development of multi-omics novel biodiscovery strategies aided by synthetic biology in order to study the heterologous expressed lichen-derived biosynthetic gene clusters in a cultivatable host offers a promising means for a sustainable supply of specialized metabolites.


Assuntos
Líquens , Líquens/genética , Líquens/metabolismo , Líquens/microbiologia , Ecossistema , Filogenia , Simbiose , Biomassa
16.
Forensic Sci Int ; 343: 111551, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36638701

RESUMO

It is a commonly held belief that drug residues may affect the integrity of DNA and/or interfere with DNA analysis, and therefore DNA on drug paraphernalia and the associated drugs may be overlooked as a source of evidence. This study investigated whether DNA could be isolated from a drug residue-bearing surface to ascertain whether a forensically useful DNA profile could be obtained. Human blood and pre-extracted "naked" DNA were deposited on samples of acetaminophen, codeine, morphine, oxycodone, ketamine, and synthetic cannabinoids and left for an hour before DNA extraction using DNA-IQ™. To investigate DNA integrity, the absolute amount of DNA recovered, degradation index, and number of PCR cycles required for the IPC to reach threshold (Ct), number of reportable alleles and average peak height (APH) in the DNA profile, were examined. The samples were also qualitatively analysed using LC:MS to determine if any residual drugs were present in the samples post-DNA extraction. Overall, the drugs had no to minimal degradation or inhibitory effects on the DNA with sufficient DNA recovered to generate a partial or full DNA profile in 80% of naked DNA samples and 100 % of blood samples. The amount of DNA collected was sufficient for further analysis in 86% of naked DNA samples, and 100% of blood samples, with all median APH values being over the 175 RFU standard. Chemical analysis showed that traces of the drug were still present in the samples after DNA extraction was performed. Therefore, this study demonstrates forensically useful DNA can be recovered from surfaces bearing drug residues, even when sampling directly from the samples of drugs.


Assuntos
Resíduos de Drogas , Humanos , Impressões Digitais de DNA , DNA/genética , Morfina , Codeína
17.
Forensic Sci Int ; 343: 111546, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36621057

RESUMO

An in-depth study into the physical substrate characteristics such as substrate surface roughness, topography, and physicochemical characteristics like wettability and surface free energy (SFE) was conducted to investigate the impact on the deposition and adherence of touch and salivary deposits on aluminium and polypropylene. A robust protocol was established to generate a set of substrates with a controlled linear surface roughness range (0.5-3.5 µm) in order to identify the impact of surface roughness on DNA transfer, persistence, prevalence, and recovery (DNA-TPPR). The polypropylene substrate was shown to produce fibres when artificially roughened, becoming more prominent at a higher surface roughness range, and has shown to have a direct impact on the distribution of salivary and touch deposits. At the low to moderate surface roughness range 0.5-2.0 µm, salivary and touch deposits have generally shown to follow the topographical features of the substrate they were deposited on, before a plateau of the surface roughness measure on the deposit was observed, indicating that a saturation point was reached and the grooves in the substrate were beginning to fill. Touch deposits have shown to maintain a consistent deposition height pre-surface roughness threshold, irrespective of substrate surface roughness while the deposition height of salivary deposits was heavily influenced by substrate surface roughness and topography. The substrate SFE, wettability, hydrophobicity, and the surface tension of the deposit was shown to drive the adhesion properties of the saliva and touch deposits on the respective substrates, and it was observed that this may be of importance for the improvement of the current DNA-TPPR understanding, DNA sampling protocols, and DNA transfer considerations within casework.


Assuntos
Polipropilenos , Tato , Molhabilidade , DNA/genética , Tensão Superficial , Propriedades de Superfície
18.
Rapid Commun Mass Spectrom ; 26(8): 943-9, 2012 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-22396031

RESUMO

RATIONALE: Speed of analysis is a significant limitation to current high-performance liquid chromatography/mass spectrometry (HPLC/MS) and ultra-high-pressure liquid chromatography (UHPLC)/MS systems. The flow rate limitations of MS detection require a compromise in the chromatographic flow rate, which in turn reduces throughput, and when using modern columns, a reduction in separation efficiency. Commonly, this restriction is combated through the post-column splitting of flow prior to entry into the mass spectrometer. However, this results in a loss of sensitivity and a loss in efficiency due to the post-extra column dead volume. METHODS: A new chromatographic column format known as 'parallel segmented flow' involves the splitting of eluent flow within the column outlet end fitting, and in this study we present its application on a HPLC electrospray ionization time-of-flight mass spectrometer. RESULTS: Using parallel segmented flow, column flow rates as high as 2.5 mL/min were employed in the analysis of amino acids without post-column splitting to the mass spectrometer. Furthermore, when parallel segmented flow chromatography columns were employed, the sensitivity was more than twice that of conventional systems with post-column splitting when the same volume of mobile phase was passed through the detector. CONCLUSIONS: These finding suggest that this type of column technology will particularly enhance the capabilities of modern LC/MS enabling both high-throughput and sensitive mass spectral detection.


Assuntos
Aminoácidos/análise , Cromatografia Líquida de Alta Pressão/instrumentação , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray/métodos
19.
J Sep Sci ; 35(9): 1110-7, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22689486

RESUMO

The need to monitor biogenic amines levels is essential for many areas of the food industry for two main reasons: the caustic nature and potential toxicity of these amines, and the potential to use amine levels as markers for freshness and quality in foodstuffs. Optimised analysis conditions used for the determination of biogenic amines derivatised with 2-napthyloxycarbonyl chloride has been applied to different pet food samples to assess the effectiveness of this method for complex sample matrices. Further to this, the use of high-resolution mass spectrometry has enabled the previously unconfirmed derivatised form of seven biogenic amines to be established. The derivatised forms identified include as mono substituted (tryptamine and histamine), bisubstituted (putrescine, cadaverine and tyramine), trisubstituted (spermidine) and tetrasubstituted (spermine). The methodology of biogenic amine determination was performed successfully to a range of pet food products highlighting the applicability to a variety of complex sample matrices.


Assuntos
Ração Animal/análise , Aminas Biogênicas/química , Contaminação de Alimentos/análise , Espectrometria de Massas/métodos , Naftalenos/química , Estrutura Molecular
20.
Forensic Sci Int ; 330: 111096, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34794062

RESUMO

A targeted sampling approach of latent DNA, deposited when a person makes contact with a surface, can prove challenging during crime scene or evidence processing, with the sampling of latent DNA often relying on the expert judgement from crime scene officers and forensic examiners. As such, the ability to use the quick and robust screening tool Diamond™ Nucleic Acid Dye (DD) was explored, with a focus on the visualisation of latent DNA on non-porous substrates, namely polypropylene, acrylic, aluminium, PVC composite material, glass, and crystalline silicon. The application of DD was performed according to methods reported in literature, where 10 µL of the dye solution (20-fold dilution of DD in 75% EtOH) was applied onto a variety of non-porous substrates via a micropipette and then subsequently visualised using a portable fluorescence microscope. It was discovered that there was scope for improvement in the reported methods due to the observation of crystal formations on all test substrates upon drying of the DD, resulting in the impaired visualisation of latent DNA and fingerprint detail. Thus, changes to the EtOH water ratio of the dye solution, and changes to the mode of dye application from a micropipette to a spray application, were explored to improve the drying time of the dye and mitigate the formation of crystals. While changes to the EtOH water ratio did not improve the overall drying time, the mode of dye application enhanced visualisation, with a spray application eliminating the formation of crystals no matter the EtOH water ratio. Visualisation with a portable Dino-Lite and Zeiss Widefield fluorescence microscope were also explored, with the Zeiss Widefield fluorescence microscope proving to be useful in whole print imaging and a more efficient imaging tool in a laboratory setting.


Assuntos
Medicina Legal , Ácidos Nucleicos , DNA , Impressões Digitais de DNA , Dermatoglifia , Corantes Fluorescentes , Humanos , Repetições de Microssatélites , Tato , Água
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