Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
EMBO Mol Med ; 15(4): e15968, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-36876653

RESUMO

Hematopoietic stem and progenitor cells (HSPCs) can establish a long-lasting microglia-like progeny in the central nervous system of properly myeloablated hosts. We exploited this approach to treat the severe CLN1 neurodegenerative disorder, which is the most aggressive form of neuronal ceroid lipofuscinoses due to palmitoyl-protein thioesterase-1 (PPT1) deficiency. We here provide the first evidence that (i) transplantation of wild-type HSPCs exerts partial but long-lasting mitigation of CLN1 symptoms; (ii) transplantation of HSPCs over-expressing hPPT1 by lentiviral gene transfer enhances the therapeutic benefit of HSPCs transplant, with first demonstration of such a dose-effect benefit for a purely neurodegenerative condition like CLN1 disease; (iii) transplantation of hPPT1 over-expressing HSPCs by a novel intracerebroventricular (ICV) approach is sufficient to transiently ameliorate CLN1-symptoms in the absence of hematopoietic tissue engraftment of the transduced cells; and (iv) combinatorial transplantation of transduced HSPCs intravenously and ICV results in a robust therapeutic benefit, particularly on symptomatic animals. Overall, these findings provide first evidence of efficacy and feasibility of this novel approach to treat CLN1 disease and possibly other neurodegenerative conditions, paving the way for its future clinical application.


Assuntos
Encéfalo , Sistema Nervoso Central , Animais , Camundongos , Modelos Animais de Doenças , Terapia Genética , Células-Tronco Hematopoéticas
2.
MAGMA ; 36(5): 737-747, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36723689

RESUMO

OBJECTIVE: We introduce a non-invasive MR-Acoustic Radiation Force Imaging (ARFI)-based elastography method that provides both the local shear modulus and temperature maps for the monitoring of High Intensity Focused Ultrasound (HIFU) therapy. MATERIALS AND METHODS: To take tissue anisotropy into account, the local shear modulus µ is determined in selected radial directions around the focal spot by fitting the phase profiles to a linear viscoelastic model, including tissue-specific mechanical relaxation time τ. MR-ARFI was evaluated on a calibrated phantom, then applied to the monitoring of HIFU in a gel phantom, ex vivo and in vivo porcine muscle tissue, in parallel with MR-thermometry. RESULTS: As expected, the shear modulus polar maps reflected the isotropy of phantoms and the anisotropy of muscle. In the HIFU monitoring experiments, both the shear modulus polar map and the thermometry map were updated with every pair of MR-ARFI phase images acquired with opposite MR-ARFI-encoding. The shear modulus was found to decrease (phantom and ex vivo) or increase (in vivo) during heating, before remaining steady during the cooling phase. The mechanical relaxation time, estimated pre- and post-HIFU, was found to vary in muscle tissue. DISCUSSION: MR-ARFI allowed for monitoring of viscoelasticity changes around the HIFU focal spot even in anisotropic muscle tissue.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Imageamento por Ressonância Magnética , Animais , Suínos , Anisotropia , Imageamento por Ressonância Magnética/métodos , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Espectroscopia de Ressonância Magnética , Acústica
3.
Phys Med Biol ; 68(3)2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36595333

RESUMO

Objective.The aim of the paper is to propose an all-in-one method based on magnetic resonance-supersonic shear wave imaging (MR-SSI) and proton resonance frequency shift (PRFS) to monitor high intensity focused ultrasound (HIFU) thermal ablations.Approach.Mechanical properties have been shown to be related to tissue damage induced by thermal ablations. Monitoring elasticity in addition to temperature changes may help in ensuring the efficacy and the accuracy of HIFU therapies. For this purpose, an MR-SSI method has been developed where the ultrasonic transducer is used for both mechanical wave generation and thermal ablation. Transient quasi-planar shear waves are generated using the acoustic radiation force, and their propagation is monitored in motion-sensitized phase MR images. Using a single-shot gradient-echo echo-planar-imaging sequence, MR images can be acquired at a sufficiently high temporal resolution to provide an update of PRFS thermometry and MR-SSI elastography maps in real time.Main results.The proposed method was first validated on a calibrated elasticity phantom, in which both the possibility to detect inclusions with different stiffness and repeatability were demonstrated. The standard deviation between the 8 performed measurements was 2% on the background of the phantom and 11%, at most, on the inclusions. A second experiment consisted in performing a HIFU heating in a gelatin phantom. The temperature increase was estimated to be 9 °C and the shear modulus was found to decrease from 2.9 to 1.8 kPa, reflecting the gel softening around the HIFU focus, whereas it remained steady in non-heated areas.Significance.The proposed MR-SSI technique allows monitoring HIFU ablations using thermometry and elastography simultaneously, without the need for an additional external mechanical exciter such as those used in MR elastography.


Assuntos
Técnicas de Imagem por Elasticidade , Tratamento por Ondas de Choque Extracorpóreas , Ablação por Ultrassom Focalizado de Alta Intensidade , Termometria , Técnicas de Imagem por Elasticidade/métodos , Termometria/métodos , Elasticidade , Ultrassom , Imageamento por Ressonância Magnética/métodos , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos
4.
Sci Rep ; 12(1): 9095, 2022 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-35641597

RESUMO

Magnetic Resonance (MR) Imaging-guided High Intensity focused Ultrasound (MRgHIFU) is a non-invasive, non-ionizing thermal ablation therapy that is particularly interesting for the palliative or curative treatment of musculoskeletal tumors. We introduce a new modular MRgHIFU device that allows the ultrasound transducer to be positioned precisely and interactively over the body part to be treated. A flexible, MR-compatible supporting structure allows free positioning of the transducer under MRI/optical fusion imaging guidance. The same structure can be rigidified using pneumatic depression, holding the transducer rigidly in place. Targeting accuracy was first evaluated in vitro. The average targeting error of the complete process was found to be equal to 5.4 ± 2.2 mm in terms of focus position, and 4.7° ± 2° in terms of transducer orientation. First-in-man feasibility is demonstrated on a patient suffering from important, uncontrolled pain from a bone metastasis located in the forearm. The 81 × 47 × 34 mm3 lesion was successfully treated using five successive positions of the transducer, under real-time monitoring by MR Thermometry. Significant pain palliation was observed 3 days after the intervention. The system described and characterized in this study is a particularly interesting modular, low-cost MRgHIFU device for musculoskeletal tumor therapy.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Neoplasias de Tecido Conjuntivo e de Tecidos Moles , Termometria , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Dor
5.
Int J Med Robot ; 13(4)2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28387448

RESUMO

BACKGROUND: Flexible bendable instruments are key tools for performing surgical endoscopy. Being able to measure the 3D position of such instruments can be useful for various tasks, such as controlling automatically robotized instruments and analyzing motions. METHODS: An automatic method is proposed to infer the 3D pose of a single bending section instrument, using only the images provided by a monocular camera embedded at the tip of the endoscope. The proposed method relies on colored markers attached onto the bending section. The image of the instrument is segmented using a graph-based method and the corners of the markers are extracted by detecting the color transitions along Bézier curves fitted on edge points. These features are accurately located and then used to estimate the 3D pose of the instrument using an adaptive model that takes into account the mechanical play between the instrument and its housing channel. RESULTS: The feature extraction method provides good localization of marker corners with images of the in vivo environment despite sensor saturation due to strong lighting. The RMS error on estimation of the tip position of the instrument for laboratory experiments was 2.1, 1.96, and 3.18 mm in the x, y and z directions, respectively. Qualitative analysis in the case of in vivo images shows the ability to correctly estimate the 3D position of the instrument tip during real motions. CONCLUSIONS: The proposed method provides an automatic and accurate estimation of the 3D position of the tip of a bendable instrument in realistic conditions, where standard approaches fail.


Assuntos
Endoscópios , Endoscopia/instrumentação , Imageamento Tridimensional/métodos , Procedimentos Cirúrgicos Robóticos/instrumentação , Cirurgia Assistida por Computador/instrumentação , Algoritmos , Automação , Endoscopia/métodos , Desenho de Equipamento , Humanos , Movimento (Física) , Imagens de Fantasmas , Reprodutibilidade dos Testes , Procedimentos Cirúrgicos Robóticos/métodos , Robótica , Cirurgia Assistida por Computador/métodos
6.
Adv Food Nutr Res ; 59: 43-62, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20610173

RESUMO

Wine quality strongly depends on the grape quality. To obtain high-quality wines, it is necessary to process healthy grapes at the correct ripeness stage and for this reason the farmer has to be especially careful in the prevention of parasite attacks on the grapevine. The most common fungal diseases affecting grape quality are downy and powdery mildew (Plasmopara viticola and Uncinula necator), and gray mold (Botrytis cinerea). On the other hand, the most dangerous insects are the grape moth (Lobesia botrana), vine mealybug (Planococcus ficus), and the citrus mealybug (Planococcus citri). Farmers fight grape diseases and insects applying pesticides that can be found at harvest time on grapes. The persistence of pesticides depends on the chemical characteristic of the active ingredients as well as on photodegradation, thermodegradation, codistillation, and enzymatic degradation. The pesticide residues on grapes can be transferred to the must and this can influence the selection and development of yeast strains. Moreover, yeasts can also influence the levels of the pesticides in the wine by reducing or adsorbing them on lees. During the fermentative process, yeasts can cause the disappearance of pesticide residues by degradation or absorption at the end of the fermentation when yeasts are deposited as lees. In this chapter, we reviewed the effect of commonly used herbicides, insecticides, and fungicides on yeasts. We also studied the effect of alcoholic and malolactic fermentation on pesticide residues.


Assuntos
Fermentação/efeitos dos fármacos , Frutas/crescimento & desenvolvimento , Praguicidas , Doenças das Plantas/prevenção & controle , Vitis , Vinho , Animais , Ascomicetos , Botrytis , Manipulação de Alimentos/métodos , Frutas/microbiologia , Frutas/parasitologia , Lactobacillus/efeitos dos fármacos , Lactobacillus/metabolismo , Mariposas , Oenococcus/efeitos dos fármacos , Oenococcus/metabolismo , Oomicetos , Resíduos de Praguicidas/análise , Praguicidas/farmacologia , Inseto Planococcus , Doenças das Plantas/microbiologia , Vinho/análise , Leveduras/efeitos dos fármacos
7.
Nat Prod Commun ; 5(2): 329-35, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20334153

RESUMO

Essential oil (EO) from aerial parts of Eucalyptus camaldulensis Dehnh., growing wild in different localities of Sardinia (Italy), was extracted by steam distillation and analyzed by gas chromatography (GC) FID and GC-ion trap mass spectrometry (ITMS). The yields of EO (v/dry wt) ranged between 0.2-0.5%. Samples were harvested between April and December to study the seasonal chemical variability of the EO. The chemical composition varied depending on the different origins and showed strong fluctuation during the vegetative stage. Thirty-seven compounds, accounting for at least 97.7% of the total EOs were identified, the major components being p-cymene (27.8-42.7%), 1,8-cineole (4.1-39.5%), beta-phellandrene (3.9-23.8%), spathulenol (2.1-15.5%) and cryptone (3.2-10.2%). The oils possessed moderate amounts (1.4-4.7%) of two uncommon aldehydes, cuminal and phellandral. The essential oils were screened for their antifungal activities against common phytopathogenic fungi using the paper disk diffusion method and they showed activity at low doses against the fungi tested. The antioxidant activity, assessed by DPPH-test and expressed as Trolox equivalent antioxidant capacity, showed values ranging between 0.5 and 5.8 mmol/L.


Assuntos
Antifúngicos/química , Antioxidantes/química , Eucalyptus/química , Óleos Voláteis/química , Óleos de Plantas/química , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Compostos de Bifenilo , Fungos/efeitos dos fármacos , Itália , Óleos Voláteis/farmacologia , Picratos , Óleos de Plantas/farmacologia
8.
J Agric Food Chem ; 57(9): 3895-900, 2009 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-19309074

RESUMO

During the liquid chromatographic study of the phenolic fraction of monofloral honeys was detected in the asphodel honey ( Asphodelus microcarpus Salzm. et Viv.) chromatogram a distinctive peak not detected in other monofloral honeys such as Arbutus unedo L., Hedysarum coronarium , Eucalyptus spp., and Galactites tomentosa . After thin layer chromatography (TLC) purification and characterization by NMR and LC-MS/MS, the compound was identified as methyl syringate (MSYR) and confirmed against an original standard. Levels of MSYR were measured in honeys of 2005, 2006, and 2007 by HPLC-DAD analysis. Level determination of MSYR was repeated in 2008 for 2006 and 2007 honeys to evaluate chemical stability of this phenolic compound. Levels of MSYR measured 1 year after the sampling did not show significant statistical differences (p < 0.05). The stability of MSYR was also confirmed by 12 asphodel honey samples collected in 2005 that showed amounts of methyl syringate comparable with those found in fresh honey. For the evaluation of MSYR origin, samples of nectars were collected from flowers and the content of MSYR was measured. Levels of MSYR in honeys are originated from the nectar with an average contribution of the nectar to the honey of 80%. Melissopalinological analysis did not allow the attribution of the honey monofloral origin because levels of asphodel pollen were <6% for all analyzed samples. Previously reported levels of MSYR for robinia, rape, chestnut, clover, linden blossom, dandelion, sunflower, thyme, manuka, and fir honeys were <5 mg/kg. For this reason, a minimum level of 122.6 mg/kg for MSYR in asphodel honeys can be considered as a chemical marker and, unlike the melissopalynological analysis, can be used for the origin attribution and to evaluate the percent of asphodel nectar in the honey.


Assuntos
Ácido Gálico/análogos & derivados , Mel/análise , Liliaceae/química , Biomarcadores/análise , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Flavonoides/análise , Ácido Gálico/análise , Mel/classificação , Fenóis/análise , Polifenóis
9.
J Environ Sci Health B ; 42(7): 817-22, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17763039

RESUMO

Fenamidone is an imidazolinone fungicide recently introduced in viticulture practices. This work reports the validation and assessment of global uncertainty of a gas chromatographic with mass spectrometry method to analyze fenamidone in grapes and wines. This method consists in a simple and fast liquid-liquid extraction step followed by chromatographic determination. Limits of detection for fenamidone in grapes and wines were, respectively, 0.05 mg/kg and 0.06 mg/L, precision was below 9.4% and average recovery was 89 +/- 5%. In the concentration range from 0.05 to 1.00 mg/kg (or mg/L) of fenamidone, global uncertainty calculated following the EURACHEM/CITAC rules, and also by the Horwitz function, was below 25%. The EURACHEM/CITAC global uncertainty budget used gave lower estimates than those obtained from the Horwitz function.


Assuntos
Resíduos de Drogas/análise , Fungicidas Industriais/análise , Cromatografia Gasosa-Espectrometria de Massas/normas , Imidazolinas/análise , Vitis/química , Vinho/análise , Qualidade de Produtos para o Consumidor , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
J Agric Food Chem ; 55(17): 7093-8, 2007 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-17658828

RESUMO

Essential oil (EO) from aerial parts (leaves, juvenile branches, and flowers when present) of Pistacia lentiscus L. growing wild in five localities of Sardinia (Italy) was extracted by steam-distillation (SD) and analyzed by gas chromatography (GC), FID, and GC-ion trap mass spectrometry (ITMS). Samples of P. lentiscus L. were harvested between April and October to study the seasonal chemical variability of the EO. A total of 45 compounds accounting for 97.5-98.4% of the total EO were identified, and the major compounds were alpha-pinene (14.8-22.6%), beta-myrcene (1-19.4%), p-cymene (1.6-16.2%), and terpinen-4-ol (14.2-28.3%). The yields of EO (v/dry w) ranged between 0.09 and 0.32%. Similar content of the major compounds was found in samples from different origins and seasonal variability was also observed. The EOs were tested for their antifungal activity against Aspergillus flavus, Rhizoctonia solani, Penicillium commune, Fusarium oxysporum. Two samples were weakly effective against Aspergillus flavus. Furthermore, terpinenol and alpha-terpineol, two of the major components of EO of Pistacia lentiscus L., totally inhibited the mycelian growth of A. flavus. Quite good antioxidant activity of the EO was also found.


Assuntos
Antioxidantes/farmacologia , Fungicidas Industriais/farmacologia , Óleos Voláteis/química , Pistacia/química , Aspergillus flavus/efeitos dos fármacos , Flores/química , Folhas de Planta/química , Caules de Planta/química , Estações do Ano , Volatilização
11.
J Agric Food Chem ; 55(3): 963-9, 2007 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-17263500

RESUMO

Quince (Cydonia oblonga Miller) fruit aqueous acetone extracts were evaluated. High-performance liquid chromatography-diode array detection and electrospray ionization-mass spectrometry were used for the identification and quantification of the phenolic compounds. The total phenolic content of the pulp and peel parts ranged from 37 to 47 and 105 to 157 mg/100 g of fresh weight, respectively. Chlorogenic acid (5-O-caffeoylquinic acid) was the most abundant phenolic compound in the pulp (37%), whereas rutin (quercetin 3-O-rutinoside) was the main one in the peel (36%). The radical scavenging potential of the extracts was determined and compared with that of synthetic antioxidants. The stronger properties corresponded to those obtained from peel material with a 70-80% inhibitory effect on DPPH radicals. The antimicrobial activity of the extracts against different microorganism strains was also investigated. Quince peel extract was the most active for inhibiting bacteria growth with minimum inhibitory and bactericide concentrations in the range of 102-5 x 103 microg polyphenol/mL. It seems that chlorogenic acid acts in synergism with other components of the extracts to exhibit their total antimicrobial activities.


Assuntos
Anti-Infecciosos/farmacologia , Flavonoides/análise , Flavonoides/farmacologia , Frutas/química , Fenóis/análise , Fenóis/farmacologia , Rosaceae/química , Antioxidantes/farmacologia , Ácido Clorogênico/análise , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polifenóis , Rutina/análise
12.
J Pharm Biomed Anal ; 41(5): 1614-9, 2006 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-16554139

RESUMO

Flavonoids and anthocyanins in berry extracts from Myrtus communis, prepared by following a typical Sardinia myrtle liqueur recipe, were identified by HPLC coupled with Electrospray Mass Spectrometry and quantified by HPLC coupled with Ultraviolet/Visible Detection in order to evaluate the stability of the extracts during 1 year of storage. Antioxidant activity was measured by using TEAC assay, and the free-radical scavenging activity was monitored during time of the stability evaluation. Anthocyanins have found to be the most instable compounds, but a considerable instability was observed also for flavonoids, suggesting the use of extracts not over 3 months from their preparation. The myrtle extract showed interesting free-radical scavenging activity. Antioxidant activity was preserved in 3 months.


Assuntos
Antioxidantes/química , Flavonoides/química , Frutas/química , Myrtus/química , Fenóis/química , Calibragem , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Sequestradores de Radicais Livres/química , Indicadores e Reagentes , Extratos Vegetais/análise , Extratos Vegetais/química , Polifenóis , Padrões de Referência , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta , Ultrassom
13.
J Chromatogr A ; 1103(2): 362-7, 2006 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-16387319

RESUMO

Famoxadone is a recent oxazolidinedione fungicide widely used in viticulture and in Integrated Pest Management strategies. In this work, after a simple and fast liquid-liquid extraction (LLE), two new gas chromatographic methods were developed to analyze famoxadone residues in grapes and wines, one with electron-capture detection (GC-ECD) and the other with mass spectrometry (GC-MS). Global uncertainties for validation parameters of both methods were compared. Limits of detection (LODs) were 0.06 and 0.02 mg/L, precision was not above 11.7 and 6.8% and recoveries were, on average, 103%+/-12 and 96%+/-12, respectively, for the GC-ECD and GC-MS methods. Similar expanded uncertainties in the range from 0.25 to 1.00 mg/L were below 35%, with increasing values for lower levels of famoxadone. GC-MS method had a lower LOD and a lower uncertainty if compared with the GC-ECD method.


Assuntos
Cromatografia Gasosa/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Oxazóis/análise , Vitis/química , Vinho/análise , Elétrons , Metacrilatos/análise , Estrobilurinas
14.
J Agric Food Chem ; 53(26): 10148-53, 2005 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-16366708

RESUMO

The chemical composition of the essential oil from flowering tops of Achillea ligustica All. was studied. Samples were collected in different localities of Sardinia (Italy) and hydrodistilled both with Clevenger-type and with simultaneous distillation-extraction apparatus. The yields ranged between 0.88 +/- 0.06 and 0.43 +/- 0.02% (vol/dry wt). The essential oils were analyzed by GC-MS, and a total of 96 components were detected. From a qualitative point of view, irrelevant differences between samples were observed. Strong chemical variability depending on the origin of the samples was observed. The major compounds found were santolina alcohol (6.7-21.8%, for the first time detected in A. ligustica), borneol (3.4-20.8%), sabinol (2.1-15.5%), trans-sabinyl acetate (0.9-17.6%), alpha-thujone (0.4-25.8%), and, among sesquiterpenes, viridiflorol (0.7-3.6%). No significant differences were detected between essential oils extracted by hydrodistillation and simultaneous distillation-extraction with CH2Cl2 and n-hexane. Antioxidant activity as DPPH radical scavenging activity was expressed in TEAC and ranged between 0.40 and 0.88 mmol/L. The antimicrobial and antifungal activities were investigated on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Penicillium commune, Fusarium oxysporum, Rizoctonia solani, and Aspergillus flavus, showing low activity.


Assuntos
Achillea/química , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Bactérias/efeitos dos fármacos , Compostos de Bifenilo , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Fungos/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Indicadores e Reagentes , Itália , Testes de Sensibilidade Microbiana , Picratos , Padrões de Referência , Terpenos/química , Terpenos/farmacologia
15.
J Chromatogr A ; 1097(1-2): 165-70, 2005 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-16298196

RESUMO

A gas chromatographic ion-trap mass spectrometry (GC-ITMS) method was developed for the determination of the fungicide zoxamide in grape, must, wine, and spirits. Samples were extracted with hexane and analyzed without any clean up. The gas chromatograph was fitted with a carbofrit inserted into the glass liner to allow large volume injections. Analyses were carried out both in EI and CI mode. Recoveries from fortified samples ranged between 86 and 114% at four different fortification levels (n=6 each), ranging between 0.05 and 2.00 mg/kg. The relative standard deviation was below 19%. Both in EI and CI mode the calculated limit of detection (LOD) and quantification (LOQ) were 0.01 and 0.05 mg/kg (0.08 mg/kg in CI), respectively. Moreover the influence of yeasts and bacteria fermentation was evaluated.


Assuntos
Amidas/análise , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Vitis/metabolismo , Álcoois/metabolismo , Amidas/química , Amidas/farmacologia , Ascomicetos/efeitos dos fármacos , Ascomicetos/metabolismo , Bebidas , Fermentação/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Cocos Gram-Positivos/efeitos dos fármacos , Cocos Gram-Positivos/metabolismo , Lactatos/metabolismo , Leuconostoc/efeitos dos fármacos , Leuconostoc/metabolismo , Malatos/metabolismo , Modelos Químicos , Estrutura Molecular , Resíduos de Praguicidas/química , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Fatores de Tempo , Vinho
16.
J Agric Food Chem ; 53(21): 8302-5, 2005 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-16218679

RESUMO

The stability of pyrethrins in formulations containing different combinations of antioxidant and sunscreen was studied with model system experiments. The mechanism of disappearance of pyrethrins was mainly due to photodegradation, but some loss by codistillation can occur. In formulations, the presence of mineral oil and emulsifiers determined a decrease on codistillation losses. The presence of the antioxidant in formulations even at high concentrations did not affect pyrethrin photodegradation rates, but rising amounts of sunscreen determined a progressive increase on half-life times of pyrethrins. A combination of sunscreen and antioxidant at low concentrations provided an effective protection against sunlight similar to that obtained by high amounts of sunscreen alone.


Assuntos
Antioxidantes/farmacologia , Inseticidas/química , Piretrinas/química , Protetores Solares/farmacologia , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Oxirredução , Fotoquímica
17.
J Agric Food Chem ; 52(11): 3530-5, 2004 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-15161226

RESUMO

The chemical composition of the essential oil of the Sardinian Rosmarinus officinalis L. obtained by hydro distillation and steam\hydro distillation was studied using GC-FID and MS. Samples were collected at different latitude and longitude of Sardinia (Italy). The yields ranged between 1.75 and 0.48% (v/w, volume/dry-weight). A total of 30 components were identified. The major compounds in the essential oil were alpha-pinene, borneol, (-) camphene, camphor, verbenone, and bornyl-acetate. Multivariate analysis carried out on chemical molecular markers, with the appraisal of chemical, pedological, and random amplified polymorphic DNA data, allows four different clusters to be distinguished. The antimicrobial and antifungal tests showed a weak activity of Sardinian rosemary. On the other hand, an inductive effect on fungal growth, especially toward Fusarium graminearum was observed.


Assuntos
Antibacterianos/análise , Fungicidas Industriais/análise , Óleos Voláteis/química , Rosmarinus/química , Rosmarinus/genética , DNA de Plantas/análise , Itália
18.
J Agric Food Chem ; 51(4): 1030-4, 2003 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-12568568

RESUMO

The chemical composition of the essential oil of the Sardinian dwarf curry plant [Helichrysum italicum G. Don ssp. microphyllum (Willd) Nym] was studied. Genetic analysis suggested the presence of two chemotypes; morphological and chemical differences confirmed the presence of two chemotypes (A and B). The maximum yields were 0.18 and 0.04% (v/w) for flowering tops and stems, respectively. The concentrations of nerol and its esters (acetate and propionate), limonene, and linalool reach their highest values during the flowering stage both in flowers and in stems. Besides the essential oil, type B showed an interesting antifungal activity.


Assuntos
Fungicidas Industriais/farmacologia , Helichrysum/química , Helichrysum/genética , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Monoterpenos Acíclicos , Cicloexenos , Flores/química , Helichrysum/crescimento & desenvolvimento , Limoneno , Monoterpenos/análise , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Caules de Planta/química , Terpenos/análise
19.
J Agric Food Chem ; 50(9): 2576-80, 2002 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-11958625

RESUMO

The disappearance of rotenone on olives under field conditions was studied. The field data showed that rotenone residues on olives decreased with a half-life (t(1/2)) of 4.0 days. After pre-harvest time (10 days) the residues were higher than the maximum residue level fixed in Italy (0.04 mg/kg). Experiments with model systems showed that the mechanism of disappearance of rotenone is not related to evaporation, thermodegradation, or co-distillation, but only to photodegradation. When the olives were processed for oil, the residues in the oil were higher than the residues on the olives by a factor of 2.4-4.8.


Assuntos
Inseticidas/análise , Resíduos de Praguicidas/análise , Óleos de Plantas/química , Rotenona/análise , Árvores/química , Cromatografia Líquida de Alta Pressão , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Inseticidas/química , Itália , Cinética , Azeite de Oliva , Fotoquímica , Rotenona/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA