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1.
Sensors (Basel) ; 24(6)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38543995

RESUMO

Chromotherapy rooms (CRs) are physical spaces with colored lights able to enhance an individual's mood, well-being, and, in the long term, their health. Virtual reality technology can be used to implement CR (VRCRs) and provide higher flexibility at lower costs. However, existing VRCRs are limited to a few use cases, and they do not fully explore the potential and pitfalls of the technology. This work contributes by comparing three VRCR designs: empty, static, and dynamic. Empty is just a void but a blue-colored environment. Static adds static abstract graphics (flowers and sea texture), and dynamic adds dynamic elements (animated star particle systems, fractals, and ocean flow). All conditions include relaxing low-beta and ocean sounds. We conducted a between-subject experiment (n = 30) with the three conditions. Subjects compiled a self-perceived questionnaire and a mathematical stress test before and after the VRCR experience. The results demonstrated that the dynamic condition provided a higher sense of presence, while the self-perceived stress level was insignificant. Dynamic VR conditions are perceived as having a shorter duration, and participants declared that they felt more involved and engaged than in the other conditions. Overall, the study demonstrated that VRCRs have a non-trivial behavior and need further study of their design, especially considering their role in a future where VR will be an everyday working interface.


Assuntos
Cromoterapia , Realidade Virtual , Humanos , Emoções , Afeto
2.
Virtual Real ; : 1-16, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37360805

RESUMO

With the high growth and prosperity of e-commerce, the retail industry needs to explore new technologies that improve digital shopping experiences. In the current technological scenario, Virtual Reality (VR) emerges as a tool and an opportunity for enhancing shopping activities, especially for the fashion industry. This study explores whether using Immersive Virtual Reality (IVR) technologies enhances the shopping experience in the fashion industry compared to Desktop Virtual Reality (DVR). A within-subject experiment was carried out involving a sample of 60 participants who completed a simulated shopping experience. In the first mode (DVR), a desktop computer setup was used to test the shopping experience using a mouse and keyboard for navigation. The second mode (IVR) exploited a Head-Mounted Display (HMD), and controllers, that allowed navigation while seated on a workstation to avoid sickness. Participants had to find a bag in the virtual shop and explore its features until they were ready to purchase it. Post-hoc measures of time duration of the shopping experience, hedonic and utilitarian values, user experience, and cognitive load were compared. Results showed that participants experienced higher hedonism and utilitarianism in the IVR shop compared to DVR. The cognitive load was comparable in both modes, while user experience was higher in IVR. In addition, the time duration of the shopping experience was higher in IVR, where users stayed immersed and enjoyed it for longer. This study has implications for fashion industry research, as the use of IVR can potentially lead to novel shopping patterns by enhancing the shopping experience. Supplementary Information: The online version contains supplementary material available at 10.1007/s10055-023-00806-y.

3.
Anal Bioanal Chem ; 413(9): 2283-2293, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33598757

RESUMO

In 2000, the Water Framework Directive (WFD) came into force in the European Union with the aim of protecting and improving water quality. The priority substances established to be monitored are predominantly organic compounds, for which the WFD sets the requirement of 'whole water sample' analysis. This legislative requirement poses analytical challenges for the monitoring laboratories as well as technical challenges for reference materials producers. In the past, there were attempts to produce reference materials as quality assurance/quality control tools for measuring organic priority substances in whole water. A critical reflection on the approaches and solutions applied to prepare such kind of matrix reference materials is presented along with a discussion on the difficulties encountered by the analytical laboratories in analysing such complex matrices. The Certified Reference Material (CRM) ERM-CA100 can be considered as a pioneer for a 'whole water' CRM (containing humic acids) and has been designed for the analysis of polycyclic aromatic hydrocarbons (PAHs). Further developments seem to be necessary to upgrade the design towards a CRM which will also include suspended particulate matter, another basic constituent of natural surface water samples.

4.
CNS Spectr ; 26(1): 62-70, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-31969204

RESUMO

BACKGROUND: For some time now, there has been a strong consensus that the migration process can influence the onset, course, development, outcome, and clinical aspects of psychiatric pathologies. METHODS: In this study, we have analyzed the influence of the migration process on the clinical expression of heroin use disorder (HUD). In a naturalistic case-control study, we compared, both at univariate and multivariate level, 30 migrant HUD (M-HUD) patients with 30 age/gender-matched Italian HUD (IT-HUD) patients. We also analyzed demographic data, drug addiction history, psychopathological symptoms, addictive behavior, and emotional reactivity to life events. RESULTS: Compared with IT-HUD pairs, at HUD Agonist Opioid Treatment, M-HUD patients were characterized by inadequate income and the presence of legal problems. They were more frequently at stage 3 of heroin addiction, with a concomitantly less frequent use of stimulants. Their age at the onset of heroin use was greater than that of subjects in the IT-HUD group. HUD post-traumatic stress disorder spectrum was present and was more severe in all M-HUD patients, but grief reactions and maladaptive behavior were the most discriminant traits. No differences were found in terms of addictive behaviors related to heroin craving or with respect to the severity/typology of psychopathology specific to HUD. CONCLUSIONS: The migratory process does not seem to be correlated with addictive behaviors or with psychopathology specific to HUD. It partly affects HUD history, and specifically correlates with emotional reactivity to loss and traumatic life events, so suggesting that in M-HUD individuals, the link between the migratory syndrome and HUD is very close.


Assuntos
Comportamento Aditivo/diagnóstico , Dependência de Heroína/diagnóstico , Migrantes/psicologia , Adulto , Comportamento Aditivo/psicologia , Estudos de Casos e Controles , Feminino , Dependência de Heroína/psicologia , Migração Humana , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Avaliação de Sintomas , Adulto Jovem
5.
Anal Chem ; 89(4): 2514-2521, 2017 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-28219247

RESUMO

In the context of supporting the EU Member States in the implementation of the EU Water Framework Directive (WFD), a project for the production of a fish reference material (ERM-CE100) certified for its content of the two priority substances hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD) was carried out at the Joint Research Centre (JRC) of the European Commission. The starting material was naturally contaminated Wels catfish (Silurus glanis), caught in the Ebro River (Spain). A novel approach for the processing of the fish was tested that resulted in a homogeneous and stable reference material in the form of a wet paste. The fresh-like texture of the matrix enhances the comparability of this material toward routinely analyzed environmental biota samples and facilitates its use as a quality assurance tool given that the WFD environmental quality standards (EQS) for biota are expressed as wet weight. Certified values for the mass fractions of HCB and HCBD were assigned with 120 ± 8 and 36 ± 4 µg/kg, respectively. The related interlaboratory comparison involved 13 expert laboratories applying a range of analytical methodologies. It is the first biota CRM ever available for HCBD. ERM-CE100 can be used to assess the performance of analytical methods employed in the mandatory monitoring of water bodies under the WFD, thus, providing a benchmark for establishing comparability among measurement results.

6.
Trends Analyt Chem ; 89: 34-40, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28413235

RESUMO

A number of different digestion methods, including aqua regia extraction following two ISO guides were used in an inter-laboratory comparison study. The results obtained showed comparable values for the total and aqua regia extractable content of As, Cu, Fe, Hg, Pb and Zn, while Cd, Co and Cr results were about 10% lower when aqua regia was employed. This small difference was covered by the between-laboratory relative standard deviation of the measurements; therefore in this study no difference in the extraction of the elements by the employed methods was found. The high organic matter content, together with low SiO2 and refractory aluminium and iron oxide amount as well as the small particle size of the sewage sludge material was reputed to have an effect on the extracting capacity of a weaker solvent such as aqua regia, bringing its results close to the total content ones.

7.
IEEE Comput Graph Appl ; 44(4): 40-52, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38968010

RESUMO

The metaverse, driven by mixed reality (MR), is positioned as the future market, revolutionizing product exploration in virtual space. Existing literature on this subject mainly focuses on business-to-consumer perspectives, leaving a gap in understanding business-to-business (B2B) applications, particularly in the fashion industry. This article introduces a "Mixed Tangible Catalog" (MTC) for B2B that combines a physical, foldable cardboard booth with an MR application linked to a head-mounted display. Targeting the fashion sector's need for high standards in material evaluation, the MTC allows retailers and distributors to browse garments, customize material attributes, and receive visual and tangible feedback. Evaluation through a focus group of 10 industry experts revealed positive feedback. The MTC maintains the tangibility of traditional B2B showrooms and reduces the environmental impact by minimizing transportation, samples, and waste. This innovative approach offers an efficient and sustainable alternative to conventional physical showrooms, enhancing both economic and ecological aspects.

8.
Anal Chim Acta ; 1315: 342757, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38879205

RESUMO

BACKGROUND: Chlorinated paraffins (CPs) are industrial chemicals categorised as persistent organic pollutants because of their toxicity, persistency and tendency to long-range transport, bioaccumulation and biomagnification. Despite having been the subject of environmental attention for decades, analytical methods for CPs still struggle reaching a sufficient degree of accuracy. Among the issues negatively impacting the quantification of CPs, the unavailability of well-characterised standards, both as pure substances and as matrix (certified) reference materials (CRMs), has played a major role. The focus of this study was to provide a matrix CRM as quality control tool to improve the comparability of CPs measurement results. RESULTS: We present the process of certification of ERM®-CE100, the first fish reference material assigned with certified values for the mass fraction of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively). The certification was performed in accordance with ISO 17034:2016 and ISO Guide 35:2017, with the value assignment step carried out via an intercomparison of laboratories of demonstrated competence in CPs analysis and applying procedures based on different analytical principles. After confirmation of the homogeneity and stability of the CRM, two certified values were assigned for SCCPs, depending on the calibrants used: 31 ± 9 µg kg-1 and 23 ± 7 µg kg-1. The MCCPs certified value was established as 44 ± 17 µg kg-1. All assigned values are relative to wet weight in the CRM that was produced as a fish paste to enhance similarity to routine biota samples. SIGNIFICANCE AND NOVELTY: The fish tissue ERM-CE100 is the first matrix CRM commercially available for the analysis of CPs, enabling analytical laboratories to improve the accuracy and the metrological traceability of their measurements. The certified CPs values are based on results obtained by both gas and liquid chromatography coupled with various mass spectrometric techniques, offering thus a broad validity to laboratories employing different analytical methods and equipment.


Assuntos
Hidrocarbonetos Clorados , Parafina , Padrões de Referência , Hidrocarbonetos Clorados/análise , Parafina/análise , Parafina/química , Animais , Peixes
9.
Sci Total Environ ; 912: 168707, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-37992820

RESUMO

The Watch List (WL) is a monitoring program under the European Water Framework Directive (WFD) to obtain high-quality Union-wide monitoring data on potential water pollutants for which scarce monitoring data or data of insufficient quality are available. The main purpose of the WL data collection is to determine if the substances pose a risk to the aquatic environment at EU level and subsequently to decide whether a threshold, the Environmental Quality Standards (EQS) should be set for them and, potentially to be listed as priority substance in the WFD. The first WL was established in 2015 and contained 10 individual or groups of substances while the 4th WL was launched in 2022. The results of monitoring the substances of the first WL showed that some countries had difficulties to reach an analytical Limit of Quantification (LOQ) below or equal to the Predicted No-Effect Concentrations (PNEC) or EQS. The Joint Research Centre (JRC) of the European Commission (EC) organised a series of workshops to support the EU Member States (MS) and their activities under the WFD. Sharing the knowledge among the Member States on the analytical methods is important to deliver good data quality. The outcome and the discussion engaged with the experts are described in this paper, and in addition a literature review of the most important publications on the analysis of 17-alpha-ethinylestradiol (EE2), amoxicillin, ciprofloxacin, metaflumizone, fipronil, metformin, and guanylurea from the last years is presented.

10.
Biomaterials ; 299: 122145, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37172536

RESUMO

Cancer is a complex pathological phenomenon that needs to be treated from different aspects. Herein, we developed a size/charge dually transformable nanoplatform (PDR NP) with multiple therapeutic and immunostimulatory properties to effectively treat advanced cancers. The PDR NPs exhibit three different therapeutic modalities (chemotherapy, phototherapy and immunotherapy) that can be used to effectively treat primary and distant tumors, and reduce recurrent tumors; the immunotherapy is simultaneously activated by three major pathways, including toll-like receptor, stimulator of interferon genes and immunogenic cell death, effectively suppresses the tumor development in combination with an immune checkpoint inhibitor. In addition, PDR NPs show size and charge responsive transformability in the tumor microenvironment, which overcomes various biological barriers and efficiently delivers the payloads into tumor cells. Taking these unique characteristics together, PDR NPs effectively ablate primary tumors, activate strong anti-tumor immunity to suppress distant tumors and reduce tumor recurrence in bladder tumor-bearing mice. Our versatile nanoplatform shows great potential for multimodal treatments against metastatic cancers.


Assuntos
Nanopartículas , Neoplasias , Animais , Camundongos , Linhagem Celular Tumoral , Nanopartículas/uso terapêutico , Recidiva Local de Neoplasia , Neoplasias/terapia , Fototerapia , Imunoterapia , Microambiente Tumoral
11.
Environ Sci Pollut Res Int ; 28(42): 59105-59118, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32415457

RESUMO

The Joint Research Centre (JRC) of the European Commission has recently released two new Certified Reference Materials (CRMs) for the analysis of brominated flame retardants (BFRs): the freshwater sediment ERM-CC537a and the fish tissue ERM-CE102. The production of these CRMs responds to the need of expanding the offer of quality assurance/quality control tools for the analysis of BFRs in the fields of environmental analysis and food control, especially for compliance purposes. The sediment ERM-CC537a carries certified values for polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD) diastereoisomers in the µg/kg range (dry mass), while the fish tissue ERM-CE102 is certified for PBDEs in the ng/kg range (wet weight). ERM-CC537a is the first reference material ever available with certified values for α-, ß- and γ-HBCDD. The assignment of the certified values was performed via an intercomparison of expert laboratories. The evaluation of the data confirms the improving trend, observed in recent years, regarding the comparability of PBDE measurement results. The relative standard deviation (RSD) among laboratories is slightly better for the fish material (8-11%) compared to the sediment (9-15%), despite lower mass fractions in the biota matrix. The RSD of HBCDD data (17%) reveals that they are more challenging analytes. The average measurement uncertainty declared by the participants is about 30%, but an in-depth analysis of their performance reveals that it should be feasible to reduce the uncertainty budget.


Assuntos
Retardadores de Chama , Hidrocarbonetos Bromados , Animais , Biota , Monitoramento Ambiental , Retardadores de Chama/análise , Água Doce , Éteres Difenil Halogenados/análise , Humanos , Hidrocarbonetos Bromados/análise
12.
J Control Release ; 329: 794-804, 2021 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-33039481

RESUMO

Development of liposomal nanomedicine with robust stability, high drug loading and synergistic efficacy is a promising strategy for effective cancer therapy. Here, we present an iron-crosslinked rosmarinic liposome (Rososome) which can load high contents of drugs (including 25.8% rosmarinic acid and 9.04% doxorubicin), keep stable in a high concentration of anionic detergent and exhibit synergistic anti-cancer efficacy. The Rososomes were constructed by rosmarinic acid-lipid conjugates which not only work synergistically with doxorubicin by producing reactive oxygen species but also provide catechol moieties for the iron cross-linkages. The cross-linkages can lock the payloads tightly, endowing the crosslinked Rososome with better stability and pharmacokinetics than its non-crosslinked counterpart. On the syngeneic mouse model of breast cancer, the iron-crosslinked Rososomes exhibit better anticancer efficacy than free rosmarinic acid, doxorubicin, non-crosslinked Rososome and commercial liposomal formulation of doxorubicin (DOXIL). This study introduces a novel strategy for the development of liposomes with robust stability, high drug loading and synergistic anti-cancer efficacy.


Assuntos
Neoplasias da Mama , Ferro , Animais , Doxorrubicina , Feminino , Humanos , Lipossomos , Camundongos , Nanomedicina
13.
J Chromatogr A ; 1619: 460944, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32059868

RESUMO

Quality-assessed analytical methods are required to determine organic priority substances (PS) in biota for the monitoring of the water status according to the EU Water Framework Directive. Although the literature describes several analytical methods to determine these substances in fish, discussion about the efficiency of the clean-up procedures to remove the lipids in the final organic extract (and decrease the disturbance of co-extractives at the detection step) is scarce. This work highlights the results of the development of an analytical method for organochlorines in fish tissue focused on the optimisation of the clean-up step in order to obtain a final extract with the lowest amount of lipids. The efficiency of the purification of the final extract was assessed by quantifying the removal of co-extractives gravimetrically, by considering the sensitivity of the gas chromatography-mass spectrometry (GC-MS) method for the analytes and by assessing the analytes' recovery. An analytical method based on accelerated solvent extraction followed by gel permeation chromatography and dual solid phase extraction (as clean-up steps) and quantification via isotope dilution GC-MS was applied to the analysis of seven PS [α-, ß-, γ- and δ-hexachlorocyclohexane (HCH) isomers, pentachlorobenzene (PeCB), hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD)]. A preliminary validation of the method was carried out with satisfactory results for all analytes in terms of intermediate precision (2.9-9.4%, except 11.8% for ß-HCH). Repeatability values were satisfactory for α-, γ-HCH, PeCB and HCB (4.3-6.9%), while the obtained results for ß-, δ-HCH and HBCD showed the need for further optimisation. Trueness was within the target performance (recovery range: 96.0-107.5%) for all analytes except ß- and δ-HCH. Limits of quantification between 0.5 and 3.3 ng/g wet weight were achieved, depending on the analytes. The proposed method can be employed to determine the mentioned PS in fish tissue with up to approximately 6% lipid content. The presented results show the challenges in establishing an analytical method which aims at balancing the required accuracy with the routine applicability (and a minimised impact on the detection system) as needed in the context of environmental monitoring.


Assuntos
Monitoramento Ambiental/métodos , Peixes , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos Clorados/análise , Lipídeos/isolamento & purificação , Poluentes Químicos da Água/análise , Animais , Clorobenzenos/análise , Hexaclorocicloexano/análise , Lipídeos/química , Reprodutibilidade dos Testes , Extração em Fase Sólida
14.
Biomaterials ; 257: 120234, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32736259

RESUMO

Gadolinium-based contrast agents (GBCAs) are the most widely used T1 contrast agents for magnetic resonance imaging (MRI) and have achieved remarkable success in clinical cancer diagnosis. However, GBCAs could cause severe nephrogenic systemic fibrosis to patients with renal insufficiency. Nevertheless, GBCAs are quickly excreted from the kidneys, which shortens their imaging window and prevents long-term monitoring of the disease per injection. Herein, a nephrotoxicity-free T1 MRI contrast agent is developed by coordinating ferric iron into a telodendritic, micellar nanostructure. This new nano-enabled, iron-based contrast agent (nIBCA) not only can reduce the renal accumulation and relieve the kidney burden, but also exhibit a significantly higher tumor to noise ratio (TNR) for cancer diagnosis. In comparison with Magnevist (a clinical-used GBCA), Magnevist induces obvious nephrotoxicity while nIBCA does not, indicating that such a novel contrast agent may be applicable to renally compromised patients requiring a contrast-enhanced MRI. The nIBCA could precisely image subcutaneous brain tumors in a mouse model and the effective imaging window lasted for at least 24 h. The nIBCA also precisely highlights the intracranial brain tumor with high TNR. The nIBCA presents a potential alternative to GBCAs as it has superior biocompatibility, high TNR and effective imaging window.


Assuntos
Neoplasias , Insuficiência Renal , Animais , Meios de Contraste , Gadolínio , Humanos , Ferro , Imageamento por Ressonância Magnética , Camundongos
15.
Chem Biol Interact ; 292: 9-14, 2018 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-29986832

RESUMO

Breast cancer chemotherapy can cause side effects due to nonspecific drug delivery, low solubility and fast metabolism of drugs used in conventional therapy. Moreover, the therapeutic effect of the drugs is often reduced by the strengthening of chemoresistance, which occurs via a variety of mechanisms. Different strategies have been developed to reduce multidrug resistance (MDR)-associated gene expressions including the use of surfactants and polymers. In this study superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with conjugated linoleic acid (CLA) reduced the number and viability of cells in comparison with both untreated cells or cells treated with SPIONs alone. This cytostatic effect correlated with the increase of peroxisome proliferator-activated receptors γ (PPARγ). The necrotic cell death induced, as a consequence, an inflammatory process, as evidenced by the decrease of the anti-inflammatory PPARα and increase of pro-inflammatory TNFα and IL-1ß. PPARs were examined because CLA is one of their natural ligands. The antitumor effect observed was accompanied by a down-regulation of p-glycoprotein (P-gp), which was the first important discovered efflux transporter belonging to MDR, and of ALDH3A1, an enzyme able to metabolize some drugs, reducing their effects. The down-regulation of P-gp correlated with the increase of cytokines. The ALDH3A1 decrease correlated with the increase of PPARγ. Based on these results, PPARs are molecular mediators of anti-cancer effect of SPIONs functionalized with CLA, being changes in these nuclear receptors correlated with induction of cytotoxicity and inflammation, and decreased ability of cancer cells in blocking anti-cancer drug effect.


Assuntos
Antineoplásicos/farmacologia , Ácidos Linoleicos Conjugados/química , Nanopartículas de Magnetita/química , Receptores Ativados por Proliferador de Peroxissomo/farmacologia , Anilidas/farmacologia , Animais , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Neoplasias da Mama , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Feminino , Interleucina-1beta/metabolismo , Ácidos Linoleicos Conjugados/uso terapêutico , Nanopartículas de Magnetita/uso terapêutico , Camundongos , Fator de Necrose Tumoral alfa/metabolismo
16.
Mater Sci Eng C Mater Biol Appl ; 76: 439-447, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28482548

RESUMO

One of the goals for the development of more effective cancer therapies with reduced toxic side effects is the optimization of innovative treatments to selectively kill tumor cells. The use of nanovectors loaded with targeted therapeutic payloads is one of the most investigated strategies. In this paper superparamagnetic iron oxide nanoparticles (SPIONs) coated by a silica shell or uncoated, were functionalized with single-layer and bi-layer conjugated linoleic acid (CLA). Silica was used to protect the magnetic core from oxidation, improve the stability of SPIONs and tailor their surface reactivity. CLA was used as novel grafting biomolecule for its anti-tumor activity and to improve particle dispersibility. Mouse breast cancer 4T1 cells were treated with these different SPIONs. SPIONs functionalized with the highest quantity of CLA and coated with silica shell were the most dispersed. Cell viability was reduced by SPIONs functionalized with CLA in comparison with cells which were untreated or treated with SPIONs without CLA. As regards the types of SPIONs functionalized with CLA, the lowest viability was observed in cells treated with uncoated SPIONs with the highest quantity of CLA. In conclusion, the silica shell free SPIONs functionalized with the highest amount of CLA can be suggested as therapeutic carriers because they have the best dispersion and ability to decrease 4T1 cell viability.


Assuntos
Nanopartículas de Magnetita , Animais , Sobrevivência Celular , Humanos , Ferro , Ácido Linoleico , Camundongos , Neoplasias , Dióxido de Silício
17.
Front Physiol ; 8: 184, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28424626

RESUMO

Bed rest has been an established treatment in the past prescribed for critically illness or convalescing patients, in order to preserve their body metabolic resource, to prevent serious complications and to support their rapid path to recovery. However, it has been reported that prolonged bed rest can have detrimental consequences that may delay or prevent the recovery from clinical illness. In order to study disuse-induced changes in muscle and bone, as observed during prolonged bed rest in humans, an innovative new model of muscle disuse for rodents is presented. Basically, the animals are confined to a reduced space designed to restrict their locomotion movements and allow them to drink and eat easily, without generating physical stress. The animals were immobilized for either 7, 14, or 28 days. The immobilization procedure induced a significant decrease of food intake, both at 14 and 28 days of immobilization. The reduced food intake was not a consequence of a stress condition induced by the model since plasma corticosterone levels -an indicator of a stress response- were not altered following the immobilization period. The animals showed a significant decrease in soleus muscle mass, grip force and cross-sectional area (a measure of fiber size), together with a decrease in bone mineral density. The present model may potentially serve to investigate the effects of bed-rest in pathological states characterized by a catabolic condition, such as diabetes or cancer.

18.
Talanta ; 116: 251-8, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24148401

RESUMO

This paper summarizes the validation strategy and the results obtained for the simultaneous determination of hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD) in fish tissue with a maximum of about 10% m/m fat content using a GC-IDMS technique. The method is applicable for the determination of HCB and HCBD at trace levels in different kinds of fish tissue samples in accordance with the requirements of the EU Directive 2008/105/EC establishing Environmental Quality Standard (EQS) levels for biota in aquatic ecosystems (10 ng/g for HCB and 55 ng/g for HCBD). The method validation aimed to assess performance parameters such as linearity, limit of detection/limit of quantification (LOD/LOQ), trueness, selectivity, intermediate precision, repeatability, stability of the extracts and robustness. The validation experiments have been performed by using uncontaminated fish tissue. Trueness was evaluated by using a certified reference material (NIST SRM 1947) (where applicable) and by the standard addition method. Very good linear signal-concentration curves were obtained for both analytes over the whole range of calibration. The repeatability and the intermediate precision of the method, expressed as relative standard deviation (RSD) and calculated at the EQS level, were estimated to be below 3% both for HCB and HCBD. The limits of quantification were 3.7 ng/g for HCB and 15.7 ng/g for HCBD in the fish. An uncertainty budget for the measurement of both HCB and HCBD in fish at about the EQS levels, applying the described method, has been established in the order of 10%. The analytical method and its performance characteristics take into account the requirements of EU Directive 2009/90/EC regarding the establishment of minimum performance criteria for the methods of analysis to be used in the water monitoring activity of the Water Framework Directive. Finally, the validated method was successfully tested on contaminated Silurus glanis from Ebro River (Spain). The method will be used in the homogeneity, stability and interlaboratory comparison studies for the characterization of a new candidate certified reference material.


Assuntos
Butadienos/isolamento & purificação , Peixes-Gato/metabolismo , Poluentes Ambientais/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas/normas , Hexaclorobenzeno/isolamento & purificação , Animais , Contaminação de Alimentos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Guias como Assunto , Técnicas de Diluição do Indicador , Limite de Detecção , Padrões de Referência , Reprodutibilidade dos Testes
20.
J Environ Monit ; 9(9): 924-30, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17726552

RESUMO

Short-chain chlorinated paraffins are a class of organic compounds widely used in many industrial applications, extensively diffused into the environment, persistent, bioaccumulative, and toxic towards aquatic organisms. However, their study and monitoring in the environment are still limited. Because of the enormous number of positional isomers that characterise their mixtures, the analysis of this class of pollutants is very difficult to perform. Beside this, the lack of certified reference materials poses a problem for the assessment of the quality assurance/quality control of any analytical procedure. At present, the scientific community does not agree on any analytical reference method, although the monitoring of short-chain chlorinated paraffins has already started in order to comply with the Water Framework Directive of the European Union on water quality. In this paper the regulatory framework, in which chlorinated paraffins are included, and the status concerning their determination are summarized. The main analytical difficulties still existing are discussed, and the definition of a method-defined parameter as well as the development of a standardised method are suggested as a way to obtain comparable monitoring data.


Assuntos
Monitoramento Ambiental/métodos , Parafina/análise , Poluentes Químicos da Água/análise , União Europeia , Halogenação , Parafina/química , Poluição da Água/análise , Poluição da Água/legislação & jurisprudência
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