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BACKGROUND AND OBJECTIVE: Skin thermal diffusivity plays a crucial role in various applications, including laser therapy and cryogenic skin cooling.This study investigates the correlation between skin thermal diffusivity and two important skin parameters, melanin content and erythema, in a cohort of 102 participants. METHODS: An in-house developed device based on transient temperature measurement was used to assess thermal diffusivity at different body locations. Melanin content and erythema were measured using a colorimeter. Statistical analysis was performed to examine potential correlations. RESULTS: The results showed that the measured thermal diffusivity values were consistent with previous reports, with variations observed among subjects. No significant correlation was found between thermal diffusivity and melanin content or erythema. This suggests that other factors, such as skin hydration or epidermis thickness, may have a more dominant influence on skin thermal properties. CONLCUSION: This research provides valuable insights into the complex interplay between skin thermal properties and physiological parameters, with potential implications for cosmetic and clinical dermatology applications.
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Melaninas , Pigmentação da Pele , Humanos , Pele/diagnóstico por imagem , Eritema , EpidermeRESUMO
We present a novel computational model of the human skin designed to investigate dielectric spectroscopy electrodes for stratum corneum hydration monitoring. The multilayer skin model allows for the swelling of the stratum corneum, as well as the variations of the dielectric properties under several hydration levels. According to the results, the stratum corneum thickness variations should not be neglected. For high hydration levels, swelling reduces the skin capacitance in comparison to a fixed stratum corneum thickness model. In addition, different fringing-field electrodes are evaluated in terms of sensitivity to the stratum corneum hydration level. As expected, both conductance and capacitance types of electrodes are influenced by the electrode geometry and dimension. However, the sensitivity of the conductance electrodes is more affected by dimension changes than the capacitance electrode leading to potential design optimization.
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Epiderme , Pele , Edema , Capacitância Elétrica , Eletrodos , HumanosRESUMO
RATIONALE: In patients with ST-segment elevation myocardial infarction (STEMI) who undergo primary percutaneous coronary intervention (pPCI), the use of dual antiplatelet therapy is essential to prevent atherothrombotic complications. Therefore, patients are treated with acetylsalicylic acid and clopidogrel, prasugrel, or ticagrelor. Clopidogrel, however, shows a major interindividual variation in antiplatelet effect, which is correlated to an increase in atherothrombotic events in patients with high platelet reactivity. This interindividual variation is partly a result of CYP2C19 genetic variants. Ticagrelor and prasugrel reduce atherothrombotic events but increase bleeding rate and drug costs, as compared with clopidogrel. CYP2C19-based tailoring of antiplatelet therapy might be beneficial to STEMI patients. STUDY DESIGN: POPular Genetics (NCT01761786) is a randomized, open-label, multicenter trial involving 2,700 STEMI patients who undergo pPCI. Patients are randomized to CYP2C19 genotyping or routine ticagrelor or prasugrel treatment. In the genotyping group, *1/*1 (wild-type) patients receive clopidogrel, and patients carrying 1 or 2 *2 or *3 loss-of-function alleles receive ticagrelor or prasugrel. The primary net clinical benefit end point is the composite of death, (recurrent) myocardial infarction, definite stent thrombosis, stroke, and Platelet Inhibition and Patient Outcomes (PLATO) major bleeding at 1 year. Primary safety end point is the composite of (PLATO) major and minor bleeding. Cost-effectiveness and quality of life will be assessed by calculating quality-adjusted life-years, net costs per life-year, and per quality-adjusted life-year gained. CONCLUSION: The POPular Genetics study is the first large-scale trial comparing CYP2C19 genotype-guided antiplatelet therapy to a nontailored strategy in terms of net clinical benefit, safety, and cost-effectiveness.
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Hidrocarboneto de Aril Hidroxilases/genética , Eletrocardiografia , Técnicas Genéticas , Infarto do Miocárdio/genética , Intervenção Coronária Percutânea/métodos , Ticlopidina/análogos & derivados , Adulto , Idoso , Hidrocarboneto de Aril Hidroxilases/metabolismo , Clopidogrel , Citocromo P-450 CYP2C19 , Feminino , Seguimentos , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/terapia , Inibidores da Agregação Plaquetária/administração & dosagem , Estudos Prospectivos , Ticlopidina/administração & dosagem , Resultado do Tratamento , Adulto JovemRESUMO
The compositions of sweat and blood are related. Therefore, sweat is an ideal noninvasive test body fluid that could replace blood for linear detection of many biomarkers, especially blood glucose. However, access to sweat samples remains limited to physical exercise, thermal stimulation, or electrical stimulation. Despite intensive research, a continuous, innocuous, and stable method for sweat stimulation and detection has not yet been developed. In this study, a nanomaterial for a sweat-stimulating gel based on the transdermal drug delivery system is presented, which transports acetylcholine chloride into the receptors of sweat glands to achieve the function of biological stimulation of skin sweating. The nanomaterial was applied to a suitable integrated sweat glucose detection device for noninvasive blood glucose monitoring. The total amount of evaporated sweat enabled by the nanomaterial is up to 35 µL·cm-2 for 24 h, and the device detects up to 17.65 µM glucose under optimal conditions, showing stable performance regardless of the user's activity level. In addition, the in vivo test was performed and compared with several studies and products, which showed excellent detection performance and osmotic relationship. The nanomaterial and associated integrated device represent a significant advance in continuous passive sweat stimulation and noninvasive sweat glucose measurement for point-of-care applications.
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Suor , Sudorese , Glicemia , Automonitorização da Glicemia , GlucoseRESUMO
Female gender has been shown to be associated with worse clinical outcomes after percutaneous coronary intervention (PCI). However, the impact of gender on the clinical outcomes of complex PCI is still poorly understood. This study examined the differences in patient and coronary lesion characteristics and longer-term clinical outcomes in male and female patients who underwent complex PCI. This was a sub-analysis of the e-ULTIMASTER study, which was a large, multicontinental, prospective, observational study enrolling 37,198 patients who underwent PCI with the Ultimaster stent. Patients who underwent complex PCI were stratified by gender. The primary outcome was target lesion failure at 12 months, defined as the composite of cardiac death, target vessel-related myocardial infarction, and clinically driven target lesion revascularization at 12 months. A total of 13,623 patients underwent complex procedures, of which 35.7% were women. Women were twice as likely as men to be aged ≥80 years (17.6% vs 9%, p <0.0001) and had a higher prevalence of cardiovascular risk factors. Women had fewer lesions treated than men (1.5 ± 0.8 vs 1.6 ± 0.8, p <0.0001) and fewer stents implanted (2.0 ± 1.1 vs 2.1 ± 1.1, p <0.0001). There was no statistically significant difference in clinical outcomes at 12 months between women and men. Event rates were comparable in women and men for target lesion failure (4.7% vs 4.3%, p = 0.30), target vessel failure (5.1% vs 4.9%, p = 0.73), and cardiac death (1.8% vs 1.7%, p = 0.80).In conclusion, our findings suggest no significant differences in clinical outcomes between women and men who underwent complex PCI.
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Angioplastia Coronária com Balão , Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Humanos , Feminino , Masculino , Intervenção Coronária Percutânea/efeitos adversos , Doença da Artéria Coronariana/terapia , Estudos Prospectivos , Fatores de Risco , Resultado do Tratamento , Angioplastia Coronária com Balão/efeitos adversos , MorteRESUMO
Up to 45% of patients who underwent percutaneous coronary intervention (PCI) may have a high bleeding risk (HBR), depending on the bleeding risk definition.1 This condition is often associated with an enhanced risk of thrombotic events with a negative impact on short- and long-term outcomes,2-8 making the choice of an appropriate antithrombotic regimen after PCI particularly challenging. Advances in stent technologies, in which the introduction of newer generations of thinner strut drug-eluting stents (DES), have significantly reduced the rate of thrombotic complications and may justify a shorter dual antiplatelet therapy (DAPT) duration. Both in vitro and in vivo studies have shown that local hemodynamic factors may critically affect the natural history of atherosclerosis. Strut thickness correlates with flow disturbances and endothelial shear stress. Flow separation within struts determines areas of recirculation with low endothelial shear stress which promotes local concentration of activated platelets.9 By mitigating inflammation, vessel injury, and neointimal proliferation, thin and streamlined struts have been associated with faster vascular healing and re-endothelization and have resulted in lower rates of thrombotic events after PCI.10,11 The use of thin strut and ultra-thin strut stents may lead to a favorable trade-off in bleeding and ischemic events in patients with HBR. However, dedicated studies evaluating the performance of thin strut versus ultrathin strut stents in patients with HBR are lacking.
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The in situ formation of gold nanoparticles into the natural polymer chitosan is described upon pulsed laser irradiation. In particular, hydrogel-type films of chitosan get loaded with the gold precursor, chloroauric acid salt (HAuCl(4)), by immersion in its aqueous solution. After the irradiation of this system with increasing number of ultraviolet laser pulses, we observe the formation of gold nanoparticles with increasing density and decreasing size. Analytical studies using absorption measurements, atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy of the nanocomposite samples throughout the irradiation procedure reveal that under the specific irradiation conditions there are two competing mechanisms responsible for the nanoparticles production: the photoreduction of the precursor responsible for the rising growth of gold particles with increasing size and the subsequent photofragmentation of these particles into smaller ones. The described method allows the localized formation of gold nanoparticles into specific areas of the polymeric films, expanding its potential applications due to its patterning capability. The size and density control of the gold nanoparticles, obtained by the accurate increase of the laser irradiation time, is accompanied by the simultaneously controlled increase of the wettability of the obtained gold nanocomposite surfaces. The capability of tailoring the hydrophilicity of nanocomposite materials based on natural polymer and biocompatible gold nanoparticles provides new potentialities in microfluidics or lab on chip devices for blood analysis or drugs transport, as well as in scaffold development for preferential cells growth.
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Quitosana/química , Ouro/química , Nanopartículas Metálicas/química , Nanocompostos/química , Nanopartículas Metálicas/ultraestrutura , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , MolhabilidadeRESUMO
AIMS: The positive predictive value of multidetector computed tomography angiography (CTA) for detecting significant stenosis remains limited. Possibly CTA may be more accurate in the evaluation of atherosclerosis rather than in the evaluation of stenosis severity. However, a comprehensive assessment of the diagnostic performance of CTA in comparison with both conventional coronary angiography (CCA) and intravascular ultrasound (IVUS) is lacking. Therefore, the aim of the study was to systematically investigate the diagnostic performance of CTA for two endpoints, namely detecting significant stenosis (using CCA as the reference standard) vs. detecting the presence of atherosclerosis (using IVUS as the reference of standard). METHODS AND RESULTS: A total of 100 patients underwent CTA followed by both CCA and IVUS. Only those segments in which IVUS imaging was performed were included for CTA and quantitative coronary angiography (QCA) analysis. On CTA, each segment was evaluated for significant stenosis (defined as ≥ 50% luminal narrowing), on CCA significant stenosis was defined as a stenosis ≥ 50%. Second, on CTA, each segment was evaluated for atherosclerotic plaque; atherosclerosis on IVUS was defined as a plaque burden of ≥ 40% cross-sectional area. CTA correctly ruled out significant stenosis in 53 of 53 (100%) patients. However, nine patients (19%) were incorrectly diagnosed as having significant lesions on CTA resulting in sensitivity, specificity, positive, and negative predictive values of 100, 85, 81, and 100%. CTA correctly ruled out the presence of atherosclerosis in 7 patients (100%) and correctly identified the presence of atherosclerosis in 93 patients (100%). No patients were incorrectly classified, resulting in sensitivity, specificity, positive, and negative predictive values of 100%. Conclusions The present study is the first to confirm using both CCA and IVUS that the diagnostic performance of CTA is superior in the evaluation of the presence or the absence of atherosclerosis when compared with the evaluation of significant stenosis.
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Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Idoso , Angiografia Coronária/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/normas , Padrões de Referência , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Elderly patients with ST-elevation myocardial infarction (STEMI) who undergo percutaneous coronary intervention (PCI) are usually excluded from major trials. HYOPTHESIS: This study sought to assess 1-year clinical outcomes following PCI with a drug-eluting stent in patients older than 80 years old with STEMI. METHODS: The large all-comer, multicontinental e-ULTIMASTER registry included 7507 patients with STEMI who underwent PCI using the Ultimaster stent. The primary clinical endpoint was 1-year target lesion failure, a composite of cardiac death (CD), target vessel-related myocardial infarction (TV-MI), or clinically driven target lesion revascularization (CD-TLR). RESULTS: There were 457 (6.1%) patients in the elderly group (≥80 years old) that were compared to 7050 (93.9%) patients <80 years. The elderly patients included more female patients and had significantly more comorbidities and had more complex coronary anatomy. The primary endpoint occurred in 7.2% of the elderly, compared to 3.1% of the younger group (p < .001). All-cause mortality was significantly higher among the elderly group compared to the younger group (10.1% vs. 2.3%, p < .0001), as well as CD (6.1% vs. 1.6%, p < .0001), but not TV-MI (1.1% vs. 0.7%, p = .34) or CD-TLR (1.1% vs. 1.4%, p = .63). CONCLUSION: Elderly patients with STEMI presentation had a higher incidence of the composite endpoint than younger patients. All-cause and CD were higher for elderly patients compared to patients younger than 80 years old. However, there was no difference in the incidence of TV-MI or target lesion revascularizations. These findings suggest that PCI for STEMI in elderly patients is relatively safe.
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Stents Farmacológicos , Infarto do Miocárdio , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST , Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Intervenção Coronária Percutânea/efeitos adversos , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico , Infarto do Miocárdio com Supradesnível do Segmento ST/cirurgia , Estudos Prospectivos , Resultado do Tratamento , Sistema de Registros , PrognósticoRESUMO
BACKGROUND AND AIMS: Patients with peripheral artery disease (PAD) represent a high risk group, and have an increased risk of cardiovascular events and worse cardiovascular outcomes. Our aim was to study the impact of PAD among patients undergoing percutaneous coronary intervention (PCI) with a newer-generation thin-strut DES. METHODS: In this analysis of the e-ULTIMASTER registry, patients with and without known PAD undergoing PCI were compared. A propensity-score was used to adjust for differences between the groups. The primary outcome was target lesion failure (TLF): a composite of cardiac death, target-vessel related myocardial infarction, and/or clinically driven target lesion revascularization at 1-year follow-up. RESULTS: Of 33,880 patients included in the analysis, PAD was present in 2255 (6.7%). Patients with PAD were older (69.0 ± 10.0 vs. 63.8 ± 11.3 years) with a higher burden of comorbidities. Patients with PAD were less likely to present with STEMI (9.6% vs. 21%), and more likely to undergo complex PCI (left main 5.5% vs. 3.0% ostial lesions 10.4% vs. 7.0%, bifurcations 14.5% vs. 12.3% and calcification 26.8% vs. 17.8%). PAD was found to be independently associated with 41% increased risk for TLF. The risk for all cause death and for cardiac death was 75% and 103% higher, respectably. No difference was found in the rates of stent thrombosis, clinically driven target lesion revascularization, or myocardial infarction (MI). CONCLUSIONS: Patients with PAD are at higher risk for (cardiac) death post PCI, but not target vessel or lesion repeat revascularizations. The PAD cohort represents a population with a higher risk clinical profile. Further research combining medical and device therapies is needed to further improve the outcomes in this high-risk population.
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Doença da Artéria Coronariana , Stents Farmacológicos , Intervenção Coronária Percutânea , Doença Arterial Periférica , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/cirurgia , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/etiologia , Doença Arterial Periférica/terapia , Prognóstico , Estudos Prospectivos , Sistema de Registros , Fatores de Risco , Resultado do TratamentoRESUMO
AIMS: Multidetector computed tomography coronary angiography (CTA) has emerged as a feasible imaging modality for non-invasive assessment of coronary artery disease (CAD). Recently, 320-row CTA systems were introduced, with 16 cm anatomical coverage, allowing image acquisition of the entire heart within a single heart beat. The aim of the present study was to assess the diagnostic accuracy of 320-row CTA in patients with known or suspected CAD. METHODS AND RESULTS: A total of 64 patients (34 male, mean age 61 +/- 16 years) underwent CTA and invasive coronary angiography. All CTA scans were evaluated for the presence of obstructive coronary stenosis by a blinded expert, and results were compared with quantitative coronary angiography. Four patients were excluded from initial analysis due to non-diagnostic image quality. Sensitivity, specificity, and positive and negative predictive values to detect > or =50% luminal narrowing on a patient basis were 100, 88, 92, and 100%, respectively. Moreover, sensitivity, specificity, and positive and negative predictive values to detect > or =70% luminal narrowing on a patient basis were 94, 95, 88, and 98%, respectively. With inclusion of non-diagnostic imaging studies, sensitivity, specificity, and positive and negative predictive values to detect > or =50% luminal narrowing on a patient basis were 100, 81, 88, and 100%, respectively. CONCLUSION: The current study shows that 320-row CTA allows accurate non-invasive assessment of significant CAD.
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Angiografia Coronária/normas , Estenose Coronária/diagnóstico por imagem , Tomografia Computadorizada por Raios X/normas , Idoso , Angiografia Coronária/métodos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodosRESUMO
The damping properties and specifically the bend losses of polymer optical fibres (POFs) have so far only been documented by experimental work, investigating bending parameters such as bending radius, length, and distance of the bends. Even though damping mechanisms and causes are well-known, no simple, generally valid formula exists. Here, a simulation technique is shown that allows producing an optical model for any bending geometries of melt-spun polymer optical fibres. The developed model takes all relevant loss mechanisms into account, especially regarding the scattering losses at the interface of core and cladding as well as those of the cladding-air interface. The latter is caused by interfacial roughness for which experimental data have been obtained by atomic force microscopy measurements. To show the validity of the simulation, the model is compared to experimental results for several fibres and a variety of geometries. The variance between model and experimental data is low (S < 4.6%). The model not only contributes to improving the understanding of the optical properties of POFs, but it also has direct applicability to the design of photonic textile sensors for medicine, where the fibres are incorporated with small bending radii.
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A dedicated nanofiber design for applications in the biomedical domain is based on the understanding of nanofiber structures. The structure of electrospun nanofibers strongly influences their properties and functionalities. In polymeric nanofibers X-ray scattering and diffraction methods, i.e. SAXS and WAXD, are capable of decoding their structural insights from about 100 nm down to the Angström scale. Here, we present a comprehensive X-ray scattering and diffraction based study and introduce new data analysis approaches to unveil detailed structural features in electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDFhfp) nanofiber membranes. Particular emphasis was placed on anisotropic morphologies being developed during the nanofiber fabrication process. Global analysis was performed on SAXS data to derive the nanofibrillar structure of repeating lamella crystalline domains with average dimensions of 12.5 nm thickness and 7.8 nm spacing along with associated tie-molecules. The varying surface roughness of the nanofiber was evaluated by extracting the Porod exponent in parallel and perpendicular direction to the nanofiber axis, which was further validated by Atomic Force Microscopy. Additionally, the presence of a mixture of the monoclinic alpha and the orthorhombic beta PVDFhfp phases both exhibiting about 6% larger unit cells compared to the corresponding pure PVDF phases was derived from WAXD. The current study shows a generic approach in detailed understanding of internal structures and surface morphology for nanofibers. This forms the basis for targeted structure and morphology steering and the respective controlling during the fabrication process with the aim to engineer nanofibers for different biomedical applications with specific requirements.
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The design of nanofibers for biomedical applications requires a deep understanding of the fiber formation process and the resulting internal structure. In this regard, non-crystalline, mesomorphic structures play a central role in the processing of many polymers as precursors in the formation of crystalline superstructures (e.g. shish-kebab) and influence strongly the physical properties of polymers with a low degree of crystallinity. Yet, our ability to probe these relevant features is often greatly limited by their low contrast differences with the amorphous phase. We present an approach to reveal the organization of the mesomorphic superstructures within such polymeric materials, on the example of electrospun poly(l-lactide) nanofibers. Based on solvent-induced crystallization, this method employs fine-tuned solvent/non-solvent systems to enhance the contrast of these structural features by selectively triggering and controlling reorganization of the phases. Hereby, the mesomorphic regions are transformed into an α-crystalline phase, while the nanoscale spatial arrangement of the underlying superstructures is preserved. Combined with X-ray analytical techniques and electron microscopy, our approach provides detailed insights into the nanofiber's inner architecture, allowing for its direct visualization. Thereby, the influence of electrospinning parameters on the fiber formation process is explained as well as the impact of the resulting non-crystalline superstructures on single fiber mechanical properties. The method can be applied to comparable polymers for the development of materials with controlled, tailored properties.
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By applying a slow curing process, we show that biomolecules can be incorporated via a simple process as liquid stable phases inside a polydimethylsiloxane (PDMS) matrix. The process is carried out under mild conditions with regards to temperature, pH and relative humidity, and is thus suitable for application to biological entities. Fluorescence and enzymatic activity measurements show that the biochemical properties of the proteins and enzyme tested are preserved, without loss due to adsorption at the liquid-polymer interface. Protected from external stimuli by the PDMS matrix, these soft liquid composite materials are new tools of interest for robotics, microfluidics, diagnostics and chemical microreactors.
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Skin burns due to accidental exposure to hot steam have often been reported to be more severe than the ones occurring from dry heat. While skin burns due to flames or radiant heat have been thoroughly characterized, the mechanisms leading to steam burns are not well understood and a conundrum still exists: can second degree burns occur without destruction of the epidermis, i.e. even before first degree burns are detected? Skin permeability is dependent both on temperature and on the kinetic energy of incoming water molecules. To investigate the mechanism underlying the injuries related to steam exposure, we used porcine skin as an ex vivo model. This model was exposed to either steam or dry heat before measuring the skin hydration via confocal Raman microspectroscopy. The results show that during the first minute of exposure to steam, the water content in both the epidermis and dermis increases. By analyzing different mechanisms of steam diffusion through the multiple skin layers, as well as the moisture-assisted bio-heat transfer, we provide a novel model explaining why steam burns can be more severe, and why steam can penetrate deeper and much faster than an equivalent dry heat.
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Queimaduras/diagnóstico , Queimaduras/etiologia , Dermatopatias/diagnóstico , Dermatopatias/etiologia , Análise Espectral Raman , Vapor/efeitos adversos , Algoritmos , Animais , Epiderme/patologia , Temperatura Alta , Microscopia , Modelos Teóricos , Índice de Gravidade de Doença , Análise Espectral Raman/instrumentação , Análise Espectral Raman/métodos , SuínosRESUMO
Neonatal jaundice (hyperbilirubinaemia) is common in neonates and, often, intensive blue-light phototherapy is required to prevent long-term effects. A photonic textile can overcome three major incubator-related concerns: Insulation of the neonate, human contact, and usage restraints. This paper describes the development of a homogeneous luminous textile from polymer optical fibres to use as a wearable, long-term phototherapy device. The bend out-coupling of light from the POFs was related to the weave production, e.g. weave pattern and yarn densities. Comfort, determined by friction against a skin model and breathability, was investigated additionally. Our textile is the first example of phototherapeutic clothing that is produced sans post-processing allowing for faster commercial production.
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The skin properties, structure, and performance can be influenced by many internal and external factors, such as age, gender, lifestyle, skin diseases, and a hydration level that can vary in relation to the environment. The aim of this work was to demonstrate the multifaceted influence of water on human skin through a combination of in vivo confocal Raman spectroscopy and images of volar-forearm skin captured with the laser scanning confocal microscopy. By means of this pilot study, the authors have both qualitatively and quantitatively studied the influence of changing the depth-dependent hydration level of the stratum corneum (SC) on the real contact area, surface roughness, and the dimensions of the primary lines and presented a new method for characterizing the contact area for different states of the skin. The hydration level of the skin and the thickness of the SC increased significantly due to uptake of moisture derived from liquid water or, to a much lesser extent, from humidity present in the environment. Hydrated skin was smoother and exhibited higher real contact area values. The highest rates of water uptake were observed for the upper few micrometers of skin and for short exposure times.
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Hidratação , Fenômenos Fisiológicos da Pele , Pele/anatomia & histologia , Pele/química , Humanos , Microscopia Confocal , Análise Espectral Raman , Propriedades de SuperfícieRESUMO
OBJECTIVES: Percutaneous coronary intervention with stent implantation is routinely performed to treat patients with obstructive coronary artery disease. However, thus far, noninvasive assessment of in-stent restenosis has been challenging. Recently, 320-row multidetector computed tomography coronary angiography (CTA) was introduced, allowing volumetric image acquisition of the heart in a single heart beat or gantry rotation. The aim of this study was to evaluate the diagnostic performance of 320-row CTA in the evaluation of significant in-stent restenosis. Invasive coronary angiography (ICA) served as the standard of reference, using a quantitative approach. MATERIALS AND METHODS: The population consisted of patients with previous coronary stent implantation who were clinically referred for cardiac evaluation because of recurrent chest pain and who underwent both CTA and ICA. CTA studies were performed using a 320-row CTA scanner with 320 detector-rows, each 0.5 mm wide, and a gantry rotation time of 350 milliseconds. Tube voltage and current were adapted to body mass index and thoracic anatomy. The entire heart was imaged in a single heart beat, with a maximum of 16-cm craniocaudal coverage. During the scan, the ECG was registered simultaneously for prospective triggering of the data. First, CTA stent image quality was assessed using a 3-point grading scale: (1) good image quality, (2) moderate image quality, and (3) poor image quality. Subsequently, the presence of in-stent restenosis was determined on a stent and patient basis by a blinded observer. Significant in-stent restenosis was defined as >or=50% luminal narrowing in the stent lumen or the presence of significant stent edge stenosis. Overlapping stents were considered to represent a single stent. Results were compared with ICA using quantitative coronary angiography. In addition, CTA stent image quality and diagnostic accuracy were related to stent characteristics and heart rate during CTA image acquisition. RESULTS: The population consisted of 53 patients (37 men, mean age: 65 +/- 13 years) with a total of 89 stents available for evaluation. ICA identified 12 stents (13%) with significant in-stent restenosis. A total of 7 stents (8%) were of nondiagnostic CTA stent image quality, and were considered positive. Sensitivity, specificity, positive, and negative predictive values were 92%, 83%, 46%, and 98%, respectively on a stent basis. Five CTA studies (9%) were of nondiagnostic quality for the evaluation of in-stent restenosis and were considered positive. Sensitivity, specificity, positive, and negative predictive values were 100%, 81%, 58%, and 100%, respectively on a patient level. Stent diameter <3 mm as well as stent strut thickness >or=140 mum were associated with decreased CTA stent image quality and diagnostic accuracy. Heart rate during CTA acquisition and stent overlap were not associated with image degradation. CONCLUSIONS: The present results show that 320-row CTA allows accurate noninvasive assessment of significant in-stent restenosis. However, stents with a large diameter and thin struts allowed better in-stent visualization than stents with a small diameter or thick struts. Consequently, noninvasive assessment of in-stent restenosis using CTA may be an attractive and feasible alternative particularly in carefully selected patients.
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Angiografia Coronária/métodos , Reestenose Coronária/diagnóstico por imagem , Reestenose Coronária/etiologia , Oclusão de Enxerto Vascular/diagnóstico por imagem , Oclusão de Enxerto Vascular/etiologia , Stents/efeitos adversos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
AIMS: This study was performed to assess the incidence, patient characteristics and predictors of aborted myocardial infarction (MI) in patients with ST-segment elevation MI (STEMI) undergoing primary percutaneous coronary intervention (PPCI). METHODS AND RESULTS: We enrolled 179 consecutive patients with STEMI within a fixed protocol for PPCI (Leiden MISSION! project); 90 patients received abciximab bolus in the hospital (in-hospital group) and 89 patients received abciximab bolus in the ambulance (pre-hospital group). Thirty-two patients (18%) fulfilled the criteria for an aborted MI. The incidence of aborted MI was four times higher in the pre-hospital abciximab group compared to the in-hospital group (OR = 4.2, 95% CI = 1.7-10.3). The median time between symptoms onset and abciximab bolus administration was significantly shorter in the aborted MI compared to established MI patients (70 vs. 115 min, p = 0.005). Multivariable analysis identified prehospital abciximab administration as the main predictor of aborted MI (OR = 2.86, 95% CI = 1.1-7.5). CONCLUSIONS: In patients with STEMI treated with PPCI, the incidence of aborted MI was 18%. Pre-hospital abciximab administration was the main predictor of aborted MI, and this effect was related to the initiation of treatment within the first two hours after symptoms onset and to the higher infarct related artery patency at presentation.