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1.
Food Chem ; 438: 138029, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38006696

RESUMO

Food fraud, along with many challenges to the integrity and sustainability, threatens the prosperity of businesses and society as a whole. Tea is the second most commonly consumed non-alcoholic beverage globally. Challenges to tea authenticity require the development of highly efficient and rapid solutions to improve supply chain transparency. This study has produced an innovative workflow for black tea geographical indications (GI) discrimination based on non-targeted spectroscopic fingerprinting techniques. A total of 360 samples originating from nine GI regions worldwide were analysed by Fourier Transform Infrared (FTIR) and Near Infrared spectroscopy. Machine learning algorithms (k-nearest neighbours and support vector machine models) applied to the test data greatly improved the GI identification achieving 100% accuracy using FTIR. This workflow will provide a low-cost and user-friendly solution for on-site and real-time determination of black tea geographical origin along supply chains.


Assuntos
Camellia sinensis , Chá , Chá/química , Fluxo de Trabalho , Camellia sinensis/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Aprendizado de Máquina , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
2.
Food Chem ; 370: 130851, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34530348

RESUMO

Health conscious and environmentally aware consumers are purchasing more organically produced foods. They prefer organic fruits and leafy vegetables as these are much less likely to have been exposed to contaminants such as pesticides. The detection of fraudulent activity in this area is difficult to undertake, because many chemical plant protection treatments degrade very quickly or can be washed off to remove evidence of their existence. It was found that when combining DART-MS with a compact, inexpensive and robust single quadrupole mass spectrometer, it was possible to differentiate organic from conventional leeks with 93.8% to 100% accuracy. ICP-MS results showed similar performance, with an ability to differentiate conventional from organic leeks with 92.5% to 98.1% accuracy. This study has paved the way for the certification of vegetables as being organically produced. The next step is to create data libraries to support the roll out of the methodologies described.


Assuntos
Cebolas , Verduras , Frutas , Espectrometria de Massas , Análise Espectral
3.
Circ Cardiovasc Interv ; 13(5): e008172, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32408819

RESUMO

BACKGROUND: The C3PO-QI (Congenital Cardiac Catheterization Project on Outcomes - Quality Improvement), a multicenter registry launched in 2015, instituted quality improvement (QI) initiatives to reduce patient radiation exposure. Through regular collaboration, this initiative would allow for harmony among active participants, maximizing efforts and efficiency at achieving radiation best practices. This study sought to report these efforts with a detailed methodology for which institutions can target initiatives, reducing radiation exposure, and increasing patient safety. METHODS: Data were collected prospectively by 8 C3PO-QI institutions between January 1, 2015 and December 31, 2017. Radiation exposure was measured in dose area product per body weight (dose area product/kg; µGy*m2/kg) and reported by expected radiation exposure categories (REC) and institution for 40 published unique procedure types. Targeted interventions addressing selected strategic domains for radiation reduction were implemented in the pediatric catheterization labs of the C3PO-QI institutions. RESULTS: The study consisted of 15 257 unique cases. Median exposure (dose area product/kg) was decreased by 30% for all procedures. Dose area product/kg was reduced in all 3 REC, with the greatest improvement observed in REC I (REC I, -37%; REC II, -23%; REC III, -27%). Although the baseline radiation exposures and exact percent decrease varied across all C3PO-QI sites, each institution demonstrated improvements in radiation dose over time. These improvements occurred with the implementation of institution-specific QI interventions accelerated by participation in the C3PO-QI multicenter collaborative. CONCLUSIONS: Substantial radiation dose reductions can be achieved using targeted QI methodology and interventions. Participation in a multicenter QI collaborative may accelerate improvement across all centers due to enhanced engagement and shared learning between sites.


Assuntos
Cateterismo Cardíaco , Angiografia Coronária , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/terapia , Doses de Radiação , Exposição à Radiação/prevenção & controle , Lesões por Radiação/prevenção & controle , Proteção Radiológica , Adolescente , Adulto , Cateterismo Cardíaco/efeitos adversos , Criança , Pré-Escolar , Angiografia Coronária/efeitos adversos , Bases de Dados Factuais , Feminino , Disparidades em Assistência à Saúde , Humanos , Lactente , Masculino , Segurança do Paciente , Estudos Prospectivos , Melhoria de Qualidade , Indicadores de Qualidade em Assistência à Saúde , Exposição à Radiação/efeitos adversos , Lesões por Radiação/etiologia , Medição de Risco , Fatores de Risco , Fatores de Tempo , Adulto Jovem
4.
J Appl Clin Med Phys ; 18(3): 207-214, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28422421

RESUMO

The workload for shielding purposes of modern linear accelerators (linacs) consists of primary and scatter radiation which depends on the dose delivered to isocenter (cGy) and leakage radiation which depends on the monitor units (MUs). In this study, we report on the workload for 10 treatment vaults in terms of dose to isocenter (cGy), monitor units delivered (MUs), number of treatment sessions (Txs), as well as, use factors (U) and modulation factors (CI) for different treatment techniques. The survey was performed for the years between 2006 and 2015 and included 16 treatment machines which represent different generations of Varian linear accelerators (6EX, 600C, 2100C, 2100EX, and TrueBeam) operating at different electron and x-ray energies (6, 9, 12, 16 and 20 MeV electrons and, 6 and 15 MV x-rays). An institutional review board (IRB) approval was acquired to perform this study. Data regarding patient workload, dose to isocenter, number of monitor units delivered, beam energies, gantry angles, and treatment techniques were exported from an ARIA treatment management system (Varian Medical Systems, Palo Alto, Ca.) into Excel spreadsheets and data analysis was performed in Matlab. The average (± std-dev) number of treatment sessions, dose to isocenter, and number of monitor units delivered per week per machine in 2006 was 119 ± 39 Txs, (300 ± 116) × 102 cGys, and (78 ± 28) × 103 MUs respectively. In contrast, the workload in 2015 was 112 ± 40 Txs, (337 ± 124) × 102 cGys, and (111 ± 46) × 103 MUs. 60% of the workload (cGy) was delivered using 6 MV and 30% using 15 MV while the remaining 10% was delivered using electron beams. The modulation factors (MU/cGy) for IMRT and VMAT were 5.0 (± 3.4) and 4.6 (± 1.6) respectively. Use factors using 90° gantry angle intervals were equally distributed (~0.25) but varied considerably among different treatment techniques. The workload, in terms of dose to isocenter (cGy) and subsequently monitor units (MUs), has been steadily increasing over the past decade. This increase can be attributed to increased use of high dose hypo-fractionated regimens (SBRT, SRS) and the increase in use of IMRT and VMAT, which require higher MUs per cGy as compared to more conventional treatment (3DCRT). Meanwhile, the patient workload in terms of treatment sessions per week remained relatively constant. The findings of this report show that variables used for shielding purposes still fall within the recommendation of NCRP Report 151.


Assuntos
Institutos de Câncer/estatística & dados numéricos , Aceleradores de Partículas , Carga de Trabalho/estatística & dados numéricos , Humanos , Radioterapia Conformacional , Espalhamento de Radiação , Inquéritos e Questionários , Fatores de Tempo
5.
Neuroimage Clin ; 6: 455-62, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25383319

RESUMO

Magnetic resonance imaging (MRI) techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE) is characterized by bilateral synchronous spike-wave discharges on electroencephalography (EEG) but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray-white blurring, fractional anisotropy (FA) measures from diffusion tensor imaging (DTI) and fractional amplitude of low frequency fluctuations (fALFF) in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray-white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC) subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE.


Assuntos
Encéfalo/patologia , Encéfalo/fisiopatologia , Epilepsia Generalizada/patologia , Epilepsia Generalizada/fisiopatologia , Adulto , Anisotropia , Mapeamento Encefálico , Imagem de Tensor de Difusão , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/patologia , Vias Neurais/fisiopatologia , Córtex Pré-Frontal/patologia , Córtex Pré-Frontal/fisiopatologia , Tálamo/patologia , Tálamo/fisiopatologia , Adulto Jovem
6.
J Antimicrob Chemother ; 60(6): 1380-3, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17905797

RESUMO

BACKGROUND: Antimutant activity of antimicrobials can be estimated by comparing drug pharmacokinetics with mutant prevention concentration (MPC). Large bacterial inocula known to reduce susceptibility have not been studied for effects on MPC determination. METHODS: Staphylococcus aureus inoculum size was varied with solid and liquid media containing daptomycin and Ca(2+), a cation expected to lower inoculum effects, to assess effects on MIC and MPC. RESULTS: With drug-containing agar, individual colonies were obtained over a narrow range of inoculum size that shifted to higher inoculum size as daptomycin concentration increased. Increasing Ca(2+) supplementation from 1 to 50 mM lowered MIC by 2-fold and MPC from 20 to 3 mg/L, the latter determined by extrapolation of population analysis profiles to an inoculum size of 10(10) cfu. Cells of colonies recovered from daptomycin-containing agar had wild-type MIC. With liquid medium, supplemented with 1 mM Ca(2+)and containing 10(10) cfu, MPC was between 2.5 and 5 mg/L at an inoculum density of 10(7) cfu/mL. Bacteria recovered from liquid assays exhibited a 4- to 8-fold increase in MIC and contained point mutations in mprF. CONCLUSIONS: Inoculum effects on MPC can be reduced by measurement with low-density (large volume) liquid bacterial cultures. Retesting putative mutants for susceptibility can be important: stable mutants having genetic variations in the mprF gene were recovered from liquid medium, but not from agar. Daptomycin MPC with S. aureus was below minimal plasma drug concentration with approved doses, which is consistent with resistance to daptomycin arising rarely.


Assuntos
Antibacterianos , Daptomicina , Farmacorresistência Bacteriana/efeitos dos fármacos , Mutação/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Ágar , Alelos , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Cálcio , Contagem de Colônia Microbiana , Meios de Cultura/química , Daptomicina/farmacocinética , Daptomicina/farmacologia , Farmacorresistência Bacteriana/genética , Seleção Genética , Staphylococcus aureus/genética , Staphylococcus aureus/crescimento & desenvolvimento
7.
J Chromatogr A ; 1160(1-2): 306-10, 2007 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-17568593

RESUMO

Mosquitoes transmit pathogens that result in diseases harmful to human, livestock, and wildlife hosts. Numerous measures can be used to reduce insect-borne disease risk to humans, and one approach is the use of topical repellents to prevent host-seeking arthropods from taking a blood meal. A current emphasis in the development of new repellents is that they be safe. Therefore, natural products sources are increasingly being explored. Compounds from plants of the mint family (Lamiaceae) have been demonstrated to be insect repellents. This study examines compounds from Etonia rosemary (Conradina etonia) to identify compounds for examination as insect repellents. Samples of Etonia rosemary were passively extracted with hexane, dichloromethane, and methanol and analyzed by GC/MS. This extraction method was chosen to eliminate thermal degradation of plant components that can occur during the distillation procedure. Additional headspace volatile compounds from this plant were identified using microscale purge-and-trap GC/MS. A variety of terpenes, terpenic alcohols, ketones, and aldehydes were identified in the extracts with terpenes and short-chained aldehydes detected in greatest abundance.


Assuntos
Compostos Orgânicos/análise , Rosmarinus/química , Cromatografia Gasosa-Espectrometria de Massas , Extratos Vegetais/química , Volatilização
8.
J Lipid Res ; 47(10): 2161-70, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16861620

RESUMO

The reversibility and regression of histological and biochemical findings in a mouse model of Gaucher disease (4L/PS-NA) was evaluated using a liver-enriched activator protein promoter control of a tetracycline-controlled transcriptional activation-responsive human acid beta-glucosidase (hGCase) transgenic system. 4L/PS-NA has the acid beta-glucosidase (GCase) V394L/V394L (4L) point mutation combined with hypomorphic ( approximately 6% wild-type) expression of the mouse prosaposin transgene (PS-NA). The hGCase/4L/PS-NA had exclusive liver expression of hGCase controlled by doxycycline (DOX). In the absence of DOX, hGCase was secreted from liver at levels of approximately 120 microg/ml serum with only approximately 8% of full activity, following exposure to pH 7.4 in serum. The hGCase activity and protein were detected in cells of the liver (massive), lung, and spleen, but not the brain. The visceral tissue storage cells and glucosylceramide (GC) accumulation in hGCase/4L/PS-NA were decreased from that in 4L/PS-NA mice. Turning off hGCase expression with dietary DOX led to reaccumulation of storage cells and of GC in liver, lung, and spleen, and macrophage activation in those tissues. This study demonstrates that conditionally expressed hGCase supplemented the existing mutant mouse GCase to control visceral substrate accumulation in vivo.


Assuntos
Modelos Animais de Doenças , Doença de Gaucher/enzimologia , Doença de Gaucher/patologia , Expressão Gênica , Glucosilceramidase/genética , Glucosilceramidase/metabolismo , Vísceras/patologia , Animais , Encéfalo/patologia , Doxiciclina/farmacologia , Feminino , Glucosilceramidase/biossíntese , Humanos , Lipídeos/análise , Fígado/patologia , Pulmão/patologia , Masculino , Camundongos , Mutação Puntual , Baço/patologia , Vísceras/metabolismo
9.
Neuroreport ; 16(17): 1893-7, 2005 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-16272874

RESUMO

Previous research indicates that long-term meditation practice is associated with altered resting electroencephalogram patterns, suggestive of long lasting changes in brain activity. We hypothesized that meditation practice might also be associated with changes in the brain's physical structure. Magnetic resonance imaging was used to assess cortical thickness in 20 participants with extensive Insight meditation experience, which involves focused attention to internal experiences. Brain regions associated with attention, interoception and sensory processing were thicker in meditation participants than matched controls, including the prefrontal cortex and right anterior insula. Between-group differences in prefrontal cortical thickness were most pronounced in older participants, suggesting that meditation might offset age-related cortical thinning. Finally, the thickness of two regions correlated with meditation experience. These data provide the first structural evidence for experience-dependent cortical plasticity associated with meditation practice.


Assuntos
Meditação , Plasticidade Neuronal , Córtex Pré-Frontal/anatomia & histologia , Adulto , Atenção , Cognição , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino
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