Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
Más filtros

Intervalo de año de publicación
1.
Sensors (Basel) ; 24(6)2024 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-38544186

RESUMEN

In biomechanics, movement is typically recorded by tracking the trajectories of anatomical landmarks previously marked using passive instrumentation, which entails several inconveniences. To overcome these disadvantages, researchers are exploring different markerless methods, such as pose estimation networks, to capture movement with equivalent accuracy to marker-based photogrammetry. However, pose estimation models usually only provide joint centers, which are incomplete data for calculating joint angles in all anatomical axes. Recently, marker augmentation models based on deep learning have emerged. These models transform pose estimation data into complete anatomical data. Building on this concept, this study presents three marker augmentation models of varying complexity that were compared to a photogrammetry system. The errors in anatomical landmark positions and the derived joint angles were calculated, and a statistical analysis of the errors was performed to identify the factors that most influence their magnitude. The proposed Transformer model improved upon the errors reported in the literature, yielding position errors of less than 1.5 cm for anatomical landmarks and 4.4 degrees for all seven movements evaluated. Anthropometric data did not influence the errors, while anatomical landmarks and movement influenced position errors, and model, rotation axis, and movement influenced joint angle errors.


Asunto(s)
Aprendizaje Profundo , Movimiento , Rotación , Fenómenos Biomecánicos , Fotogrametría
2.
Biofouling ; 32(2): 179-90, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26813295

RESUMEN

Bacteriophage-host interaction studies in biofilm structures are still challenging due to the technical limitations of traditional methods. The aim of this study was to provide a direct fluorescence in situ hybridization (FISH) method based on locked nucleic acid (LNA) probes, which targets the phage replication phase, allowing the study of population dynamics during infection. Bacteriophages specific for two biofilm-forming bacteria, Pseudomonas aeruginosa and Acinetobacter, were selected. Four LNA probes were designed and optimized for phage-specific detection and for bacterial counterstaining. To validate the method, LNA-FISH counts were compared with the traditional plaque forming unit (PFU) technique. To visualize the progression of phage infection within a biofilm, colony-biofilms were formed and infected with bacteriophages. A good correlation (r = 0.707) was observed between LNA-FISH and PFU techniques. In biofilm structures, LNA-FISH provided a good discrimination of the infected cells and also allowed the assessment of the spatial distribution of infected and non-infected populations.


Asunto(s)
Acinetobacter baumannii/virología , Bacteriófagos/fisiología , Biopelículas/crecimiento & desarrollo , Hibridación Fluorescente in Situ/métodos , Pseudomonas aeruginosa/virología , Oligonucleótidos/metabolismo , Reproducibilidad de los Resultados
3.
Appl Microbiol Biotechnol ; 99(12): 5307-16, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25666680

RESUMEN

A survey in 16 activated sludge wastewater treatment plants (WWTP) was conducted to contribute to the knowledge of the environmental parameters that determine the composition of the filamentous community. A total of 128 samples of mixed liquor from municipal WWTP were collected during 2 years, and 22 filamentous morphotypes were identified. The most frequent and abundant filamentous bacteria were, in both cases and by this order, type 0041/0675, type 0092, Microthrix parvicella and 1851, nocardioforms and Haliscomenobacter hydrossis. Concerning dominance, type 1851 was the most frequently dominant morphotype, followed by M. parvicella and types 0092 and 0041/0675. These were also, and by this order, the dominant morphotypes during bulking occurrences. Significant correlations were obtained between the abundance of filamentous bacteria and environmental parameters, but multivariate statistical analysis only confirmed the correlation between type 0092 and Sludge Volume Index (SVI), emphasizing the association of this filament with bulking. The discussion of the results in light of published works was complicated by the random use of terms such as frequency, abundance, and dominance with different and often unclear meanings. This reinforces the need of clarifying these terms when discussing the causes of filamentous overgrowth in WWTP.


Asunto(s)
Bacterias/aislamiento & purificación , Aguas del Alcantarillado/microbiología , Bacterias/clasificación , Bacterias/genética , Ecosistema , Portugal , Aguas del Alcantarillado/análisis , Aguas Residuales/análisis , Aguas Residuales/microbiología , Purificación del Agua/instrumentación , Purificación del Agua/métodos
4.
Nutr Cancer ; 66(8): 1371-85, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25356800

RESUMEN

Lactoferrin (LF) is predominantly found in mammalian secretions with recognized anticancer potential, although the mechanisms involved in such activity are still unclear. Here, the stability, internalization, and cytotoxicity of bovine LF (bLF) and its variants were tested against a panel of breast cancer cells. bLF was found to be very stable under incubation with cells and also able to internalize them, although most of the protein remained in the culture medium. Furthermore, bLF (up to 30 µM) inhibited the growth of breast cancer cells (T-47D, MDA-MB-231, Hs578T, and MCF-7) in a higher extent than in the normal counterpart cell line (MCF-10-2A), thus suggesting its selectivity. Regarding its variants, only the iron-saturated protein showed a higher activity compared with the commercial bLF. bLF growth inhibitory activity was associated with the induction of cell cycle arrest, but not with apoptosis. Moreover, exposure to bLF increased the cells phospho-AMPKα levels and decreased both phospho threonine mammalian target of rapamycin (mTOR) and total mTOR levels, indicating a novel mechanism of action through its ability to induce nutrient/energy-related stress. This study disclosed important findings to better understand the mechanisms underlying the bLF effects on breast cancer cell lines, which could be valuable for novel advances in the cancer research field.


Asunto(s)
Antineoplásicos/farmacología , Neoplasias de la Mama/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Lactoferrina/farmacología , Serina-Treonina Quinasas TOR/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Apoptosis/efectos de los fármacos , Bovinos , Línea Celular Tumoral , Regulación hacia Abajo , Femenino , Humanos , Células MCF-7 , Fosforilación , Serina-Treonina Quinasas TOR/genética
5.
Environ Technol ; 35(9-12): 1525-31, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24701952

RESUMEN

An urban wastewater treatment plant (WWTP) with two different parallel lines of treatment and located in the north of Portugal was studied during four months, following recurrent episodes of filamentous bulking caused by Sphaerotilus natans and eventual occurrences of Nocardioforms and Type 1863. An aerobic selector was introduced in both lines in the beginning of the studied period, suppressed in one of the lines during six weeks, and then put into operation again until the end of the study. A total of 14 filamentous bacteria morphotypes were identified. The results showed that the presence of an aerobic biological selector in continuous operation prevented the overgrowth of the filamentous Type 1863, of Nocardioforms and, in particular, of S. natans. Simultaneously, it allowed lowering the oxygen levels in the aeration tanks without negative consequences in the overall performance of the WWTP, namely bulking occurrence. Dissolved oxygen (DO) in the aeration tank varied initially between 2 and 3 mg/L, but the introduction of the selector enabled to lower it to 1-1.5 mg/L in the aeration tank and around 0.5 mg/L in the selector. A significant energy save was allowed, even considering the aeration of the selector. The results are more relevant if one considers the fact that the main cause of the bulking problems in this WWTP was the overgrowth of S. natans, a filamentous bacterium known to be stimulated by low DO levels.


Asunto(s)
Sphaerotilus/fisiología , Administración de Residuos , Aguas Residuales/microbiología , Aerobiosis
6.
Gait Posture ; 108: 215-221, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38118225

RESUMEN

BACKGROUND: Human movement analysis is usually achieved by tracking markers attached to anatomical landmarks with photogrammetry. Such marker-based systems have disadvantages that have led to the development of markerless procedures, although their accuracy is not usually comparable to that of manual palpation procedures. New motion acquisition systems, such as 3D temporal scanners, provide homologous meshes that can be exploited for this purpose. RESEARCH QUESTION: Can fixed vertices of a homologous mesh be used to identify anatomical landmarks with an accuracy equivalent to that of manual palpation? METHODS: We used 3165 human shape scans from the CAESAR dataset, with labelled locations of anatomical landmarks. First, we fitted a template mesh to the scans, and assigned a vertex of that mesh to 53 anatomical landmarks in all subjects. Then we defined a nominal vertex for each landmark, as the more centred vertex out of the set assigned for that landmark. We calculated the errors of the template-fitting and the nominal vertex determination procedures, and analysed their relationship to subject's sex, height and body mass index, as well as their size compared to manual palpation errors. RESULTS: The template-fitting errors were below 5 mm, and the nominal vertex determination errors reached maximum values of 24 mm. Except for the trochanter, those errors were the same order of magnitude or smaller than inter-examiner errors of lower limb landmarks. Errors increased with height and body mass index, and were smaller for men than for women of the same height and body mass index. SIGNIFICANCE: We defined a set of vertices for 53 anatomical landmarks in a homologous mesh, which yields location errors comparable to those obtained by manual palpation for the majority of landmarks. We also quantified how the subject's sex and anthropometric features can affect the size of those errors.


Asunto(s)
Cabeza , Extremidad Inferior , Masculino , Humanos , Femenino , Fémur , Antropometría , Índice de Masa Corporal , Imagenología Tridimensional , Puntos Anatómicos de Referencia
7.
Data Brief ; 53: 110157, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38375138

RESUMEN

In this paper, we present a dataset that takes 2D and 3D human pose keypoints estimated from images and relates them to the location of 3D anatomical landmarks. The dataset contains 51,051 poses obtained from 71 persons in A-Pose while performing 7 movements (walking, running, squatting, and four types of jumping). These poses were scanned to build a collection of 3D moving textured meshes with anatomical correspondence. Each mesh in that collection was used to obtain the 3D locations of 53 anatomical landmarks, and 48 images were created using virtual cameras with different perspectives. 2D pose keypoints from those images were obtained using the MediaPipe Human Pose Landmarker, and their corresponding 3D keypoints were calculated by linear triangulation. The dataset consists of a folder for each participant containing two Track Row Column (TRC) files and one JSON file for each movement sequence. One TRC file is used to store the 3D data of the triangulated 3D keypoints while the other contains the 3D anatomical landmarks. The JSON file is used to store the 2D keypoints and the calibration parameters of the virtual cameras. The anthropometric characteristics of the participants are annotated in a single CSV file. These data are intended to be used in developments that require the transformation of existing human pose solutions in computer vision into biomechanical applications or simulations. This dataset can also be used in other applications related to training neural networks for human motion analysis and studying their influence on anthropometric characteristics.

8.
Complement Ther Clin Pract ; 55: 101847, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38498964

RESUMEN

BACKGROUND: Pregnancy induces physiological changes, commonly marked by nausea and vomiting in the first trimester, posing risks for both mother and baby. This study evaluates the effects of auriculotherapy on nausea and vomiting during the first trimester of pregnancy. MATERIALS AND METHODS: A randomized clinical trial was conducted in two primary health care centers with 56 Brazilian pregnant women who reported nausea or vomiting in the first trimester. The participants were divided into an intervention group (auriculotherapy with seeds) and a placebo group (sham auriculotherapy). The intervention was divided into three moments: pre-intervention with assessment of nausea and vomiting and application of questionnaires, and two follow-ups conducted on the fourth and seventh day of the intervention, with reassessment of nausea and vomiting. RESULTS: Both groups experienced a decrease in nausea and vomiting over time, with no statistically significant differences between groups in the within-group analyses at various time points. The intervention group had a greater reduction in symptoms. Within the intervention group, symptoms were more common among ferrous sulfate users and those without reported dietary disturbances. In addition, a higher incidence of nausea and vomiting was associated with the use of analgesics, morning snacks, and low intake of protein, vegetables, and fruits. CONCLUSIONS: The intervention did not affect the between-group differences in the incidence of nausea and vomiting and vomiting effort in the first trimester of pregnancy. However, a greater reduction was observed in the intervention group.


Asunto(s)
Auriculoterapia , Complicaciones del Embarazo , Femenino , Embarazo , Humanos , Mujeres Embarazadas , Resultado del Tratamiento , Vómitos/terapia , Náusea/terapia , Complicaciones del Embarazo/terapia
9.
Biofouling ; 29(7): 829-40, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23837894

RESUMEN

In this study, single and dual species biofilms of Pseudomonas aeruginosa and Escherichia coli, two common bacteria associated with urinary tract infections, were formed in silicon coupons immersed in artificial urine medium. In single species experiments, E. coli appeared to form biofilms more easily than P. aeruginosa. In mixed biofilms, both species apparently benefited from the presence of the other, as the average Log total cells cm(-2) of mixed biofilms (7.29 cells cm(-2)) was higher than obtained for single cultures (6.99 cells cm(-2)). However, the use of selective media seemed to indicate that P. aeruginosa was the only microorganism to benefit in mixed biofilms (Log 7 CFU of P. aeruginosa cm(-2), compared to Log 6 CFU cm(-2) obtained in pure cultures). Peptide nucleic acid-fluorescence in situ hybridization combined with confocal laser scanning microscopy confirmed that E. coli was indeed being outnumbered by P. aeruginosa at 48 h. Whereas E. coli is the main causative agent of catheter-associated urinary tract infections, the results from this study indicate that the reason for the higher prevalence of this microorganism is not related to an enhanced ability to form biofilm and outcompete other species that may also be present, but rather to a better ability to form single-species biofilms possibly due to a more frequent access to the catheter surface.


Asunto(s)
Biopelículas , Incrustaciones Biológicas , Escherichia coli/fisiología , Pseudomonas aeruginosa/fisiología , Siliconas/química , Catéteres Urinarios/microbiología , Orina , Técnicas de Cocultivo , Hibridación Fluorescente in Situ , Propiedades de Superficie
10.
Environ Technol ; 34(13-16): 1947-56, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24350448

RESUMEN

A very compact flat microbial fuel cell (MFC), with 64 cm2 each for the anode surface and the cathode surface and 1 cm3 each for the anode and cathode chambers, was tested for wastewater treatment with simultaneous electricity production with the ultimate goal of implementing an autonomous service in decentralized wastewater treatment systems. The MFC was operated with municipal wastewater in sequencing batch reactor mode with re-circulation. Current densities up to 407 W/m3 and a carbon removal of 83% were obtained. Interruption in the operation slightly decreased power density, while the re-circulation ratio did not influence power generation. The anode biofilm presented high conductivity, activity and diversity. The denaturing gradient gel electrophoresis band-pattern of the DNA showed the presence of several ribotypes with different species of Shewanellaceae and Geobacteraceae families.


Asunto(s)
Fuentes de Energía Bioeléctrica/microbiología , Eliminación de Residuos Líquidos/instrumentación , Eliminación de Residuos Líquidos/métodos , Biopelículas , Carbono/química , Electroforesis en Gel de Gradiente Desnaturalizante , Conductividad Eléctrica , Hierro/química , Viabilidad Microbiana , Microscopía Confocal , Aguas Residuales/química , Aguas Residuales/microbiología
11.
Artículo en Inglés | MEDLINE | ID: mdl-22375539

RESUMEN

Recent studies reporting on the useful implementation of fungi in wastewater treatment plants triggered the need to improve fungi based systems. Therefore, it is crucial to investigate the conditions that promote their selection. The present work aims to study the effect of the organic loading rate on the growth of filamentous fungi. Three sequencing batch reactors (SBR), fed with an easily biodegradable substrate (acetate), were operated at different organic loading rates: 4.3 g COD L(-1) day(-1) (SBR1), 1.0 g COD L(-1) day(-1) (SBR2) and 0.5 g COD L(-1) day(-1) (SBR3). High amounts of fungal filaments were observed in the SBR operating at higher organic loading rate, as ascertained by direct microscopic inspection, while, at lower organic loading rates, overabundance of fungal filaments was not observed. Sequence retrieved from the isolated fungal filaments presented high similarity (99 %) to Galactomyces geotrichum.


Asunto(s)
Ascomicetos/crecimiento & desarrollo , Aguas del Alcantarillado , Microbiología del Suelo , Secuencia de Bases , Cartilla de ADN , Reacción en Cadena de la Polimerasa
12.
Rev Esc Enferm USP ; 46(3): 711-9, 2012 Jun.
Artículo en Portugués | MEDLINE | ID: mdl-22773494

RESUMEN

The objective of this study was to evaluate the knowledge, attitude and practices of women prisoners regarding the use of female and male condoms as a means of prevention against STD/HIV. This quantitative and evaluative Knowledge, Attitude and Practice (KAP) study included 155 female prisoners. Data collection was performed between January and March 2010 at the State of Ceará Women's Penitentiary. Although the women had heard of and/or knew about the purposes of the use of condoms, only 35 (22.6%) had appropriate knowledge regarding male condoms, and 11 (7.1%) in regards to the use of female condoms. Their attitudes were less favorable regarding oral sex. Appropriate practice was not significantly representative, particularly regarding the female condom. Homo/bisexuality, gender issues, lack of knowledge, and the difficult access to condoms are obstacles that must be considered in the promotion of sexual health in the studied group.


Asunto(s)
Condones Femeninos/estadística & datos numéricos , Condones/estadística & datos numéricos , Infecciones por VIH/prevención & control , Conocimientos, Actitudes y Práctica en Salud , Prisioneros , Adulto , Femenino , Humanos
13.
Sci Total Environ ; 838(Pt 1): 155957, 2022 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-35580680

RESUMEN

DEPTAL MCL® is a professional cleaning agent approved by the Portuguese Food Regulatory Authority and is used in agro-food industries, namely in fish canning industries in the north of Portugal. Its extensive use during cleaning procedures results in potential significant negative impacts on the performance of the downstream municipal wastewater treatment plant (WWTP). A lab-scale extended areation activated sludge wastewater treatment system, continuously fed by influent collected at a municipal WWTP, was used to assess the impact of a range of DEPTAL MCL® concentrations during 72 h. Despite distinct activated sludge community composition (due to its dynamic nature) and variations in real influent characteristics, a relevant impact was observed. DEPTAL MCL® effect was underscored through the use of a multivariate analysis using seventeen physicochemical operational factors and nineteen quantitative image analysis (QIA) parameters. DEPTAL MCL® exerted a severe negative impact on phosphorous (P-PO4) removal, total nitrogen (TN) removal and sludge volume index (SVI). With increasing DEPTAL MCL® concentrations, both P-PO4 and TN removal were affected and diminished proportionally. Moreover, several QIA parameters indicate defloculation when DEPTAL MCL® was present, in particular for intermediate size aggregates with significant impacts. Optical density of the effluent (Ode), displayed an increase of effluent turbidity. Percentage of area covered by small aggregates (%Areasml) was also significantly higher for the intermediate and higher DEPTAL MCL® concentrations tested. Principal component analysis exhibited 3 distinct ordenations: (i) control without addition of DEPTAL MCL®; (ii) addition of 0.03% and 0.06% and of (iii) 0.13 and 0.26% (v DEPTAL MCL®/v aeration tank). Canonical correspondence analysis (CCA) was used to correlate the physicochemical data, QIA and the filamentous bacteria species prevalence to DEPTAL MCL® concentration and incubation time. A time persistent DEPTAL MCL® effect was observed, underscoring the need of a pretreatment of wastewater containing this cleaning agent.


Asunto(s)
Aguas del Alcantarillado , Purificación del Agua , Animales , Bacterias , Reactores Biológicos , Nitrógeno , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/microbiología
14.
Gait Posture ; 97: 28-34, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35868094

RESUMEN

BACKGROUND: Combining the accuracy of marker-based stereophotogrammetry and the usability and comfort of markerless human movement analysis is a difficult challenge. 3D temporal scanners are a promising solution, since they provide moving meshes with thousands of vertices that can be used to analyze human movements. RESEARCH QUESTION: Can a 3D temporal scanner be used as a markerless system for gait analysis with the same accuracy as traditional, marker-based stereophotogrammetry systems? METHODS: A comparative study was carried out using a 3D temporal scanner synchronized with a marker-based stereophotogrammetry system. Two gait cycles of twelve healthy adults were measured simultaneously, extracting the positions of key anatomical points from both systems, and using them to analyze the 3D kinematics of the pelvis, right hip and knee joints. Measurement differences of marker positions and joint angles were described by their root mean square. A t-test was performed to rule out instrumental errors, and an F-test to evaluate the amplifications of marker position errors in dynamic conditions. RESULTS: The differences in 3D landmark positions were between 1.9 and 2.4 mm in the reference pose. Marker position errors were significantly increased during motion in the medial-lateral and vertical directions. The angle relative errors were between 3% and 43% of the range of motion, with the greatest difference being observed in hip axial rotation. SIGNIFICANCE: The differences in the results obtained between the 3D temporal scanner and the marker-based system were smaller than the usual errors due to lack of accuracy in the manual positioning of markers on anatomical landmarks and to soft-tissue artefacts. That level of accuracy is greater than other markerless systems, and proves that such technology is a good alternative to traditional, marker-based motion capture.


Asunto(s)
Marcha , Fotogrametría , Adulto , Fenómenos Biomecánicos , Humanos , Rango del Movimiento Articular , Rotación
15.
Exp Gerontol ; 166: 111883, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35792286

RESUMEN

OBJECTIVE: Although the use of resveratrol is widespread, there is a lack of studies concerning its use in older adults who practice regular physical activity. The present study aimed to evaluate how resveratrol influenced anthropometric parameters, heart measures, blood analytes in women participants, aged 60 to 80 years old, distributed in four groups consisting of those who regularly exercise or not, and those who were under resveratrol treatment or not. The older adult women exercised in a Community Center. METHODS: A prospective, comparative clinical pilot study was carried out based on convenience non-probability sampling. Resveratrol 300 mg/daily/60 days was orally-administered to 43 participants that were regularly accompanied and checked for anthropometrical parameters, heart measures, blood analytes, leukogram, and plaquetogram indices. RESULTS: The effect of resveratrol and exercise was not significant in most of the parameters evaluated in the study. Nonetheless, both systolic (p = 0.0120) and diastolic (p = 0.0241) blood pressures (BP) were elevated in sedentary older adult women in comparison with older women that regularly exercised. However, they remained within the normal BP range considered for the age. Mean corpuscular volume (MCH; p = 0.0198) and red blood cell distribution width (RDW; p < 0.0001) were improved in the groups receiving resveratrol and exercises compared to the sedentary group receiving resveratrol. The sedentary group receiving resveratrol showed diminished segmented cells (p = 0.0459), basophils (p < 0.0001), and lymphocytes (p < 0.0001). CONCLUSIONS: Present findings showed that resveratrol consumption for sedentary older women could lead to dysregulated blood pressure. Although resveratrol consumption is indicated to treat inflammation, its use must be discussed with a health professional and not be inadvertently self-administered due to significant alterations in blood pressure in older adult women, primarily if not related to exercise practice.


Asunto(s)
Presión Sanguínea , Anciano , Anciano de 80 o más Años , Antropometría , Femenino , Humanos , Proyectos Piloto , Estudios Prospectivos , Resveratrol/farmacología
16.
Acta Biomater ; 139: 237-248, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34358697

RESUMEN

The search for alternative antimicrobial strategies capable of avoiding resistance mechanisms in bacteria are highly needed due to the alarming emergence of antimicrobial resistance. The application of physical stimuli as a mean of sensitizing bacteria for the action of antimicrobials on otherwise resistant bacteria or by allowing the action of low quantity of antimicrobials may be seen as a breakthrough for such purpose. This work proposes the development of antibacterial nanocomposites using the synergy between the electrically active microenvironments, created by a piezoelectric polymer (poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE)), with green-synthesized silver nanoparticles (AgNPs). The electrical microenvironment is generated via mechanical stimulation of piezoelectric PVDF-TrFE/AgNPs films using a lab-made mechanical bioreactor. The generated material's electrical response further translates to bacterial cells, namely Escherichia coli and Staphylococcus epidermidis which in combination with AgNPs and the specific morphological features of the material induce important antibacterial and antibiofilm activity. Both porous and non-porous PVDF composites have shown antibacterial characteristics when stimulated at a mechanical frequency of 4 Hz being the effect boosted when AgNPs were incorporated in the nanocomposite, reducing in more than 80% the S. epidermidis bacterial growth in planktonic and biofilm form. The electroactive environments sensitize the bacteria allowing the action of a low dose of AgNPs (1.69% (w/w)). Importantly, the material did not compromise the viability of mammalian cells, thus being considered biocompatible. The piezoelectric stimulation of PVDF-based polymeric films may represent a breakthrough in the development of antibacterial coatings for devices used at hospital setting, taking advantage on the use of mechanical stimuli (pressure/touch) to exert antibacterial and antibiofilm activity. STATEMENT OF SIGNIFICANCE: The application of physical methods in alternative to the common chemical ones is seen as a breakthrough for avoiding the emergence of antimicrobial resistance. Antimicrobial strategies that take advantage on the capability of bacteria to sense physical stimuli such as mechanical and electrical cues are scarce. Electroactive nanocomposites comprised of poly(vinylidene fluoride-co-trifluoroethylene (PVDF-TrFE) and green-synthesized silver nanoparticles (AgNPs) were developed to obtain material able to inhibit the colonization of microorganisms. By applying a mechanical stimuli to the nanocomposite, which ultimately mimics movements such as walking or touching, an antimicrobial effect is obtained, resulting from the synergy between the electroactive microenvironments created on the surface of the material and the AgNPs. Such environments sensitize the bacteria to low doses of antimicrobials.


Asunto(s)
Nanopartículas del Metal , Nanocompuestos , Animales , Antibacterianos/química , Antibacterianos/farmacología , Nanopartículas del Metal/química , Pruebas de Sensibilidad Microbiana , Nanocompuestos/química , Polímeros/química , Polímeros/farmacología , Plata/química , Plata/farmacología , Staphylococcus epidermidis
17.
Rev Esc Enferm USP ; 56: e20220082, 2022.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-36219589

RESUMEN

OBJECTIVE: to assess the effects of "Piss off, HPV!", an educational intervention to increase adolescents' knowledge, attitude and compliance with human papillomavirus vaccination. METHOD: a randomized clinical trial by cluster, carried out in six schools in two municipalities in Ceará, with 238 girls. The control group (n = 120) received routine instructions, and the intervention group (n = 118), printed message cards about the quadrivalent HPV vaccine. A pre- and post-intervention knowledge, attitude and practice survey was applied to both groups. The McNemar test, to analyze knowledge, attitude and pre- and post-intervention practice, the chi-square test, to compare compliance in relation to knowledge and attitude, and a logistic regression model, to assess vaccine compliance, were carried out. A significance level of 5% was adopted. RESULTS: pre-intervention, knowledge was inadequate and attitude was adequate in both groups. Post-intervention, adequate knowledge and practices became greater in the intervention group. Adequate post-intervention knowledge and attitude, in addition to being 12 years of age or older, increase the chance for vaccination, explaining 70% of the practice. CONCLUSION: the educational intervention was effective for adolescents' knowledge and compliance with the quadrivalent HPV vaccine. UTN: U1111-1254-5546; ReBEC: RBR-107hzdqt.


Asunto(s)
Infecciones por Papillomavirus , Vacunas contra Papillomavirus , Adolescente , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Infecciones por Papillomavirus/prevención & control , Aceptación de la Atención de Salud , Encuestas y Cuestionarios , Vacunación
18.
J Biomed Biotechnol ; 2011: 568932, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22131813

RESUMEN

Frutalin is the α-D-galactose-binding lectin isolated from breadfruit seeds. Frutalin was obtained from two different sources: native frutalin was purified from its natural origin, and recombinant frutalin was produced and purified from Pichia pastoris. This work aimed to study and compare the effect of native and recombinant frutalin on HeLa cervical cancer cells proliferation and apoptosis. Furthermore, the interaction between frutalin and the HeLa cells was investigated by confocal microscopy. Despite having different carbohydrate-binding affinities, native and recombinant frutalin showed an identical magnitude of cytotoxicity on HeLa cells growth (IC50~100 µg/mL) and equally induced cell apoptosis. The interaction studies showed that both lectins were rapidly internalised and targeted to HeLa cell's nucleus. Altogether, these results indicate that frutalin action is not dependent on its sugar-binding properties. This study provides important information about the bioactivity of frutalin and contributes to the understanding of the plant lectins cytotoxic activity.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Galectinas/farmacología , Pichia/química , Proteínas Recombinantes/farmacología , Antineoplásicos/química , Femenino , Galectinas/química , Galectinas/genética , Células HeLa , Humanos , Microscopía Confocal , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Semillas/química
19.
Curr Microbiol ; 62(4): 1128-32, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21140149

RESUMEN

Persistent urinary tract infections (UTI) are often caused by E. coli adhered to urothelium. This type of cells is generally recognized as very tolerant to antibiotics which renders difficult the treatment of chronic UTI. This study investigates the use of lytic bacteriophages as alternative antimicrobial agents, particularly the interaction of phages with E. coli adhered to urothelium and specifically determines their efficiency against this type of cells. The bacterial adhesion to urothelium was performed varying the bacterial cell concentrations and the period and conditions (static, shaken) of adhesion. Three collection bacteriophages (T1, T4, and phiX174 like phages) were tested against clinical E. coli isolates and only one was selected for further infection experiments. Based on the lytic spectrum against clinical isolates and its ability to infect the highest number of antibiotic resistant strains, the T1-like bacteriophage was selected. This bacteriophage caused nearly a 45% reduction of the bacterial population after 2 h of treatment. This study provides evidence that bacteriophages are effective in controlling suspended and adhered cells and therefore can be a viable alternative to antibiotics to control urothelium- adhered bacteria.


Asunto(s)
Adhesión Bacteriana , Bacteriófagos/fisiología , Terapia Biológica/métodos , Infecciones por Escherichia coli/terapia , Escherichia coli/virología , Especificidad del Huésped , Infecciones Urinarias/terapia , Línea Celular , Escherichia coli/fisiología , Infecciones por Escherichia coli/microbiología , Humanos , Infecciones Urinarias/microbiología , Urotelio/microbiología
20.
Rev Esc Enferm USP ; 45(1): 55-61, 2011 Mar.
Artículo en Portugués | MEDLINE | ID: mdl-21445489

RESUMEN

The purpose of this study was to trace the contraceptive history of sterilized women and identify the associations between educational, sexual and obstetric variables and the women's age when they underwent the procedure for tubal ligation (TL). This is a retrospective documentary study performed at the Lígia Barros Costa Natural Birthing Center in Fortaleza, Ceará, with 1423 records, dating from 2005 to 2008, 277 of which referred to sterilized women. Data analysis involved applying the calculation of frequencies, Pearson's chi-square test and correlation of Pearson/Spearman. Sterilized women represented a population with low education, marital union, and a history of infrequent use of other contraceptive methods other than condoms and the pill. Numbers of pregnancies and abortions/miscarriages were related with the age of TL, unlike the variables of education and the age of the first sexual intercourse. With this knowledge at hand, nurses can improve their look towards women looking forward to TL, and thus strengthen education strategies and promote greater diversity in the alternatives for contraception.


Asunto(s)
Esterilización Tubaria/estadística & datos numéricos , Adulto , Femenino , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Factores Socioeconómicos , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA