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1.
J Mater Sci Mater Med ; 31(11): 100, 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33130982

RESUMO

The use of 3D scaffolds based on mesoporous bioactive glasses (MBG) enhanced with therapeutic ions, biomolecules and cells is emerging as a strategy to improve bone healing. In this paper, the osteogenic capability of ZnO-enriched MBG scaffolds loaded or not with osteostatin (OST) and human mesenchymal stem cells (MSC) was evaluated after implantation in New Zealand rabbits. Cylindrical meso-macroporous scaffolds with composition (mol %) 82.2SiO2-10.3CaO-3.3P2O5-4.2ZnO (4ZN) were obtained by rapid prototyping and then, coated with gelatin for easy handling and potentiating the release of inorganic ions and OST. Bone defects (7.5 mm diameter, 12 mm depth) were drilled in the distal femoral epiphysis and filled with 4ZN, 4ZN + MSC, 4ZN + OST or 4ZN + MSC + OST materials to evaluate and compare their osteogenic features. Rabbits were sacrificed at 3 months extracting the distal third of bone specimens for necropsy, histological, and microtomography (µCT) evaluations. Systems investigated exhibited bone regeneration capability. Thus, trabecular bone volume density (BV/TV) values obtained from µCT showed that the good bone healing capability of 4ZN was significantly improved by the scaffolds coated with OST and MSC. Our findings in vivo suggest the interest of these MBG complete systems to improve bone repair in the clinical practice.


Assuntos
Fraturas Ósseas/terapia , Vidro/química , Células-Tronco Mesenquimais/citologia , Proteína Relacionada ao Hormônio Paratireóideo/química , Fragmentos de Peptídeos/química , Alicerces Teciduais/química , Óxido de Zinco/química , Animais , Materiais Biocompatíveis , Regeneração Óssea , Feminino , Íons , Teste de Materiais , Osteogênese , Porosidade , Coelhos , Microtomografia por Raio-X , Zinco/química
2.
Opt Express ; 27(8): A257-A268, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31052880

RESUMO

Heliostat alignment evaluation is among the main issues in solar tower concentration plant operation and maintenance. This paper describes a novel method used to evaluate heliostat misalignment and its experimental verification. This method provides a different way of visualizing beam centroid pointing errors by generating the complete deviation curve for each axis. This, for example, would be useful for verifying a heliostat's correct alignment by using a measurement performed out of the receiver target, using these traces to calculate its reflection's expected location, given a known misalignment. This measurement could be performed during operation simply by including a reflective element in the heliostat and two detector arrays on the tower's surface. This model has been tested for various types of misalignments of a heliostat at different hours, dates, and heliostat locations. The simulation results have been validated by using an experimental setup at a scale of 1:100.

3.
Radiologia ; 58(1): 7-15, 2016.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-26655801

RESUMO

Chronic venous insufficiency of the lower limbs is very prevalent. In recent decades, Doppler ultrasound has become the method of choice to study this condition, and it is considered essential when surgery is indicated. This article aims to establish a method for the examination, including venous mapping and preoperative marking. To this end, we review the venous anatomy of the lower limbs and the pathophysiology of chronic venous insufficiency and explain the basic hemodynamic concepts and the terminology required to elaborate a radiological report that will enable appropriate treatment planning and communication with other specialists. We briefly explain the CHIVA (the acronym for the French term "cure conservatrice et hémodynamique de l'insuffisance veineuse en ambulatoire"=conservative hemodynamic treatment for chronic venous insufficiency) strategy, a minimally invasive surgical strategy that aims to restore correct venous hemodynamics without resecting the saphenous vein.


Assuntos
Ultrassonografia Doppler , Insuficiência Venosa/diagnóstico por imagem , Humanos , Veias/diagnóstico por imagem
4.
Dermatol Online J ; 18(8): 12, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22948062

RESUMO

A 48-year-old woman developed drug-induced subacute lupus erythematosus while taking lamotrigine. The eruption resolved after discontinuance of lamotrigine, suggesting this drug as the cause.


Assuntos
Anticonvulsivantes/efeitos adversos , Lúpus Eritematoso Cutâneo/induzido quimicamente , Triazinas/efeitos adversos , Toxidermias/imunologia , Feminino , Humanos , Lamotrigina , Lúpus Eritematoso Cutâneo/imunologia , Pessoa de Meia-Idade
5.
Opt Express ; 18(14): 15201-6, 2010 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-20640005

RESUMO

A novel technique is introduced for jitter-insensitive sub-KHz resolution linewidth characterization technique in ultra-narrow lasers for optical communication applications. The technique is based on self-heterodyne detection induced by Stimulated Brillouin Scattering (SBS). Non linear SBS drives the heterodyne mixing through optical frequency locking of a narrow tunable laser source and the signal under test, which is modulated in the low frequency range. Due to SBS nature, jitter variations in the optical frequency do not affect the correlation spectra measured with resolution figures up to 300 Hz, without the need for optical delay line as in conventional homodyne correlation techniques.

7.
Acta Biomater ; 114: 395-406, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32717329

RESUMO

Bone regeneration is a clinical challenge which requires multiple approaches. Sometimes, it also includes the development of osteogenic and antibacterial biomaterials to treat the emergence of possible infection processes arising from surgery. This study evaluates the antibacterial properties of gelatin-coated meso-macroporous scaffolds based on the bioactive glass 80%SiO2-15%CaO-5%P2O5 (mol-%) before (BL-GE) and after being doped with 4% of ZnO (4ZN-GE) and loaded with both saturated and the minimal inhibitory concentrations of one of the antibiotics: levofloxacin (LEVO), vancomycin (VANCO), rifampicin (RIFAM) or gentamicin (GENTA). After physical-chemical characterization of materials, release studies of inorganic ions and antibiotics from the scaffolds were carried out. Moreover, molecular modelling allowed determining the electrostatic potential density maps and the hydrogen bonds of antibiotics and the glass matrix. Antibacterial in vitro studies (in planktonic, inhibition halos and biofilm destruction) with S. aureus and E. coli as bacteria models showed a synergistic effect of zinc ions and antibiotics. The effect was especially noticeable in planktonic cultures of S. aureus with 4ZN-GE scaffolds loaded with VANCO, LEVO or RIFAM and in E. coli cultures with LEVO or GENTA. Moreover, S. aureus biofilms were completely destroyed by 4ZN-GE scaffolds loaded with VANCO, LEVO or RIFAM and the E. coli biofilm total destruction was accomplished with 4ZN-GE scaffolds loaded with GENTA or LEVO. This approach could be an important step in the fight against microbial resistance and provide needed options for bone infection treatment. STATEMENT OF SIGNIFICANCE: Antibacterial capabilities of scaffolds based on mesoporous bioactive glasses before and after adding a 4% ZnO and loading with saturated and minimal inhibitory concentrations of levofloxacin, vancomycin, gentamicin or rifampicin were evaluated. Staphylococcus aureus and Escherichia coli were the infection model strains for the performed assays of inhibition zone, planktonic growth and biofilm. Good inhibition results and a synergistic effect of zinc ions released from scaffolds and antibiotics were observed. Thus, the amount of antibiotic required to inhibit the bacterial planktonic growth was substantially reduced with the ZnO inclusion in the scaffold. This study shows that the ZnO-MBG osteogenic scaffolds are multifunctional tools in bone tissue engineering because they are able to fight bacterial infections with lower antibiotic dosage.


Assuntos
Antibacterianos , Staphylococcus aureus , Antibacterianos/farmacologia , Escherichia coli , Vidro , Dióxido de Silício , Alicerces Teciduais , Zinco
8.
Opt Express ; 17(8): 6753-8, 2009 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-19365504

RESUMO

Suitable use of stimulated Brillouin amplification (SBA) effect for selective single peak amplification in an optical frequency comb is demonstrated to provide high accuracy in optical frequency metrology. A pump wave generated by a tunable laser source (TLS) is used to stimulate SBA of such optical comb along an optical fiber and selectively amplify only one single peak of the comb. Nature of SBA preserves both linewidth and absolute wavelength position of the selected comb peak. All of these features result in a simple, robust and compact all in fiber system. Relative optical frequency accuracy in the order of Hz is confirmed.


Assuntos
Amplificadores Eletrônicos , Tecnologia de Fibra Óptica/instrumentação , Filtração/instrumentação , Dispositivos Ópticos , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Lasers , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Clin Exp Dermatol ; 34(5): 598-602, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19094123

RESUMO

BACKGROUND: Pyoderma gangrenosum (PG) is an uncommon condition, but can lead to the diagnosis of an underlying systemic disease. It can appear spontaneously or as a result of the pathergy phenomenon after trauma or surgery. METHODS: We review three patients with postoperative PG (PPG) and the relevant literature. We also report an accurate method for microbial detection by 16S ribosomal (r)RNA sequencing. RESULTS: A 47-year-old woman and two men aged 54 and 48 years, respectively, presented with sterile ulcerations after surgery. Associated conditions (Crohn's disease and leukaemia) were present. Surgical wound infection was suspected and systemic empirical antibiotics were prescribed. After infection was excluded, PPG was diagnosed and corticosteroids were started. DISCUSSION: PPG should be considered in the differential diagnosis of postsurgical wound complications. Recognition of this condition may prevent unnecessary administration of antimicrobial treatment and development of more extensive ulcerations. It may also be the clue for the diagnosis of an underlying systemic disease. We discuss the usefulness of 16S rRNA sequencing for microbial detection and identification in order to exclude a causative infection in patients who have previously received antibiotic treatment.


Assuntos
Complicações Pós-Operatórias/diagnóstico , Pioderma Gangrenoso/diagnóstico , RNA Ribossômico 16S/genética , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/patologia , Pioderma Gangrenoso/microbiologia , Pioderma Gangrenoso/patologia , Infecção da Ferida Cirúrgica/diagnóstico
10.
Acta Biomater ; 89: 359-371, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30890462

RESUMO

There is an urgent need of biosynthetic bone grafts with enhanced osteogenic capacity. In this study, we describe the design of hierarchical meso-macroporous 3D-scaffolds based on mesoporous bioactive glasses (MBGs), enriched with the peptide osteostatin and Zn2+ ions, and their osteogenic effect on human mesenchymal stem cells (hMSCs) as a preclinical strategy in bone regeneration. The MBG compositions investigated were 80%SiO2-15%CaO-5%P2O5 (in mol-%) Blank (BL), and two analogous glasses containing 4% ZnO (4ZN) and 5% ZnO (5ZN). By using additive fabrication techniques, scaffolds exhibiting hierarchical porosity: mesopores (around 4 nm), macropores (1-600 µm) and big channels (∼1000 µm), were prepared. These MBG scaffolds with or without osteostatin were evaluated in hMCSs cultures. Zinc promoted hMSCs colonization (both the surface and inside) of MBG scaffolds. Moreover, Zn2+ ions and osteostatin together, but not independently, in the scaffolds were found to induce the osteoblast differentiation genes runt related transcription factor-2 (RUNX2) and alkaline phosphatase (ALP) in hMSCs after 7 d of culture in the absence of an osteogenic differentiation-promoting medium. These results add credence to the combined use of zinc and osteostatin as an effective strategy for bone regeneration applications. STATEMENT OF SIGNIFICANCE: Mesoporous bioactive glasses (MBGs) are bioceramics whose unique properties make them excellent materials for bone tissue engineering. Physico-chemical characterization of MBGs as scaffolds made by rapid prototyping, doped with zinc (potential osteogenic, angiogenic and bactericidal ion) and loaded with osteostatin (osteogenic peptide) are described. These Zn-MBGs scaffolds showed 3D hierarchical meso-macroporous structure that enables to host and release osteostatin. When decorated with human mesenchymal stem cells (hMSCs), MBGs scaffoldsenriched with both zinc and osteostatin exhibited a synergistic effect to enhance hMSCs growth, and also hMSCs osteogenic differentiationwithout addition of other osteoblastic differentiation factors to the culture medium. This novel strategy has a great potential for use in bone tissue engineering.


Assuntos
Diferenciação Celular , Vidro/química , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/metabolismo , Osteocalcina/farmacologia , Alicerces Teciduais/química , Zinco/química , Cátions Bivalentes/química , Humanos , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Porosidade
11.
Opt Express ; 16(14): 10658-63, 2008 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-18607480

RESUMO

We present a method to generate an optical reference comb signal with subpicometer wavelength accuracy. XPM nonlinear effect in a fiber is used to get an optical frequency comb signal, free of frequency chirp and wavelength instabilities, from a pulsed gain-switched laser diode. Principles of such comb generation are presented as well as the application of this comb as a ruler to measure frequency differences in high resolution optical spectrum measurements. To confirm this method, Brillouin filtering optical spectrometric technique is used to characterize a modulated optical source. Typical resolution of this technique allows 0.08 pm wavelength accuracy.


Assuntos
Lasers , Óptica e Fotônica , Espectrofotometria/métodos , Calibragem , Desenho de Equipamento , Refratometria/métodos , Reprodutibilidade dos Testes , Espalhamento de Radiação
13.
Opt Express ; 15(7): 3708-14, 2007 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-19532617

RESUMO

A high-resolution light intensity spectrum analyzer technique to derive the RF modulation spectrum of optical signals is presented and experimentally confirmed. It uses the XPM nonlinear effect in a dispersion shifted fiber to obtain the light intensity spectrum, and a Brillouin optical filtering method to implement the high resolution spectrometric analysis. Measured RF spectra of PRBS modulated optical signals at 2.5 Gb/s and 10 Gb/s are presented and compared with their corresponding ones obtained in the electrical detection domain to confirm the capabilities of the method.Influence of fiber electrostriction effect is measured and analyzed.

14.
Rev Esp Anestesiol Reanim ; 54(3): 155-61, 2007 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-17436653

RESUMO

OBJECTIVE: To assess the effects of a single dose of tranexamic acid on bleeding and requirement for blood product transfusion in children undergoing cardiac surgery with cardiopulmonary bypass. PATIENTS AND METHODS: A prospective study of closed cohorts undergoing pediatric heart surgery was carried out. The children weighed between 4 and 10 kg. Reoperated and cyanotic patients were included in the sample. The treatment group received 50 mg x kg(-1) of tranexamic acid before surgery. Analyzed data collected during the first 24 hours after surgery were biochemical parameters, bleeding, use of blood products, and D-dimer levels. RESULTS: Fifty-three patients, 25 in the treatment group, were enrolled. Patients on treatment had 24.8% less bleeding in the first 24 hours after surgery (P = .02). The transfusion of blood products was 20% less in the treatment group, although the difference was not significant except in the subgroup of patients who were reoperated. In that group the amount of blood products transfused was 72% less than in the control group (P = .05). D-dimer levels were also lower in the treatment group (P = .003). No adverse effects attributable to the treatment were observed. CONCLUSIONS: A single preoperative dose of tranexamic acid to inhibit fibrinolysis reduces bleeding 24.8% in pediatric patients undergoing heart surgery with cardiopulmonary bypass. The effect is greater in reoperated patients, leading to a reduction in their requirement for transfusion. The use of this therapy in these patients is therefore highly justified.


Assuntos
Antifibrinolíticos/uso terapêutico , Perda Sanguínea Cirúrgica , Procedimentos Cirúrgicos Cardíacos , Hemorragia Pós-Operatória/tratamento farmacológico , Ácido Tranexâmico/uso terapêutico , Antifibrinolíticos/administração & dosagem , Biomarcadores , Proteínas Sanguíneas/análise , Ponte Cardiopulmonar/efeitos adversos , Estudos de Coortes , Terapia Combinada , Transfusão de Eritrócitos/estatística & dados numéricos , Feminino , Fibrinólise/efeitos dos fármacos , Cardiopatias Congênitas/cirurgia , Humanos , Lactente , Masculino , Hemorragia Pós-Operatória/sangue , Hemorragia Pós-Operatória/terapia , Pré-Medicação , Estudos Prospectivos , Reoperação , Ácido Tranexâmico/administração & dosagem , Resultado do Tratamento
15.
Artigo em Inglês | MEDLINE | ID: mdl-27106813

RESUMO

We test the capabilities of in situ Raman spectroscopy for non-destructive analysis of degradation processes in invaluable masterpieces, as well as for the characterization of minerals and prehistoric rock-art in caves. To this end, we have studied the mechanism of decay suffered by the 15th-century limestone sculptures that decorate the retro-choir of Burgos Cathedral (N Spain). In situ Raman probe detected hydrated sulfate and nitrate minerals on the sculptures, which are responsible for the decay of the original limestone. In addition, in situ Raman analyses were performed on unique speleothems in El Soplao Cave (Cantabria, N Spain) and in the Gruta de las Maravillas (Aracena, SW Spain). Unusual cave minerals were detected in El Soplao Cave, such as hydromagnesite (Mg5(CO3)4(OH)2·4H2O), as well as ferromanganese oxides in the black biogenic speleothems recently discovered in this cavern. In the Gruta de las Maravillas, gypsum (CaSO4·2H2O) was identified for the first time, as part of the oldest cave materials, so providing additional evidence of hypogenic mechanisms that occurred in this cave during earlier stages of its formation. Finally, we present preliminary analyses of several cave paintings in the renowned "Polychrome Hall" of Altamira Cave (Cantabria, N. Spain). Hematite (Fe2O3) is the most abundant mineral phase, which provides the characteristic ochre-reddish color to the Altamira bison and deer paintings. Thus, portable Raman spectroscopy is demonstrated to be an analytical technique compatible with preserving our cultural and natural heritage, since the analysis does not require physical contact between the Raman head and the analyzed items.

19.
Gac Sanit ; 7(37): 164-8, 1993.
Artigo em Espanhol | MEDLINE | ID: mdl-8375968

RESUMO

Vaccine efficacy, the effectiveness of a vaccination programme and the fraction of a population that would be necessary to vaccinate in order to prevent a measles outbreak are studied in a population having a vaccination programme. A dynamic model for acute, directly transmitted diseases was applied, based on the rate of transmission, namely, the probability that the infectious agent is transmitted from an infected to a susceptible person within a short space of time. We carried out a population-based study where we observed the final attack rates among vaccinated and unvaccinated people for a measles outbreak. In this population, the vaccination programme is responsible for a reduction of: 82.41% of all cases in the non-vaccinated sector; 98.45% of the average risk of disease among the vaccinated; and 97.29% of all cases among the population as a whole. Under these conditions there is the possibility of disease outbreaks arising, outbreaks which could be prevented if the percentage of the vaccinated population exceeded 95%.


Assuntos
Surtos de Doenças/prevenção & controle , Vacina contra Sarampo/imunologia , Sarampo/prevenção & controle , Criança , Surtos de Doenças/estatística & dados numéricos , Avaliação de Medicamentos , Humanos , Sarampo/epidemiologia , Avaliação de Programas e Projetos de Saúde , Estudos Retrospectivos , Espanha/epidemiologia , População Urbana/estatística & dados numéricos
20.
Am J Occup Ther ; 50(7): 516-25, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8819603

RESUMO

This article describes the Volitional Questionnaire and presents recent empirical efforts to develop and validate this instrument. The Volitional Questionnaire is an observational method of gathering data on motivation that is designed for persons who are unable to self-report their own motives. Studies to date suggest that the instrument can provide a valid measure of volition, though a number of limitations of the tool are noted. Implications for use of the Volitional Questionnaire in practice and for further refinement and future research are discussed.


Assuntos
Terapia Ocupacional/métodos , Autoimagem , Humanos , Sensibilidade e Especificidade , Inquéritos e Questionários , Volição
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