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The increasing demand for innovative approaches in wound healing and skin regeneration has prompted extensive research into advanced biomaterials. This review focuses on showcasing the unique properties of sustainable silk-based particulate systems in promoting the controlled release of pharmaceuticals and bioactive agents in the context of wound healing and skin regeneration. Silk fibroin and sericin are derived from well-established silkworm production and constitute a unique biocompatible and biodegradable protein platform for the development of drug delivery systems. The controlled release of therapeutic compounds from silk-based particulate systems not only ensures optimal bioavailability but also addresses the challenges associated with conventional delivery methods. The multifaceted benefits of silk proteins, including their inherent biocompatibility, versatility, and sustainability, are explored in this review. Furthermore, the intricate mechanisms by which controlled drug release takes place from silk-based carriers are discussed.
Subject(s)
Fibroins , Silk , Silk/metabolism , Delayed-Action Preparations , Wound Healing , Skin/metabolism , Biocompatible Materials/therapeutic use , Fibroins/metabolismABSTRACT
Abstract This paper analyzes ethno-racial residential segregation in two large metropolitan areas across the Global North and South: London (UK) and São Paulo (Brazil). Residential segregation is measured and mapped using global and local spatial segregation indices that portray different spatial dimensions across scales. To interpret results, the study adopted a relational approach that juxtaposes global figures and local variations of segregation, complementary dimensions of segregation (dissimilarity and exposure/isolation), multiple scales of segregation, and location patterns of different ethno-racial groups. Results indicate that London and São Paulo metropolitan regions have similar, although inverse, core-periphery patterns of ethno-racial segregation. The findings also revealed that segregation levels are higher for London than São Paulo across scales and dimensions, indicating that, against common assumptions, London is more ethno-racially segregated than São Paulo. These findings are discussed in the context of existing literature, exploring similarities and differences between ethno-racial segregation in the two metropolitan regions. The paper concludes with a discussion on the relevance of the comparative findings for segregation studies, and a reflection on future studies on urban segregation.
Resumo Este artigo analisa a segregação residencial do ponto de vista étnico-racial em duas grandes regiões metropolitanas localizadas no Sul e Norte Globais: Londres (Reino Unido) e São Paulo (Brasil). Utilizaram-se índices espaciais globais e locais para mapear e mensurar as diferentes dimensões espaciais e escalas da segregação étnico-racial nas duas metrópoles. O estudo adotou uma abordagem relacional para a interpretação dos resultados que justapõe resultados globais e variações locais da segregação, dimensões espaciais complementares (dissimilaridade e exposição/isolamento), múltiplas escalas geográficas e padrões de localização espacial dos diferentes grupos étnico-raciais. Os resultados indicam que as regiões metropolitanas de Londres e São Paulo apresentam padrões espaciais de segregação centro-periferia similares, mas inversos. Os resultados também relevaram que os níveis de segregação de Londres são mais altos do que os de São Paulo, indicando que contraintuitivamente Londres é mais segregada étnico-racialmente do que São Paulo. Esses resultados são discutidos no contexto da literatura, explorando as similaridades e diferenças entre as duas regiões metropolitanas. O artigo conclui com uma discussão sobre a relevância dos resultados e uma reflexão sobre a agenda futura para os estudos sobre a segregação urbana.
Resumen Este artículo analiza la segregación residencial desde un punto de vista étnico-racial en dos grandes regiones metropolitanas ubicadas en el Sur y el Norte Global: Londres (Reino Unido) y San Pablo (Brasil). Se usaron índices espaciales globales y locales para mapear y medir las diferentes dimensiones espaciales y escalas de la segregación étnico-racial en las dos metrópolis. El estudio adoptó un enfoque relacional para interpretar los resultados que yuxtapone resultados globales y variaciones locales de segregación, dimensiones espaciales complementarias (disimilaridad y exposición/aislamiento), múltiples escalas geográficas y patrones de ubicación espacial de diferentes grupos etnorraciales. Los resultados indican que las regiones metropolitanas de Londres y San Pablo presentan patrones espaciales similares, pero inversos, de segregación centro-periferia. Los resultados también revelaron que los niveles de segregación en Londres son más altos que en San Pablo, lo que indica que, contraintuitivamente, Londres está más segregada étnico-racialmente que San Pablo. Estos resultados se discuten en el contexto de la literatura, explorando las similitudes y diferencias entre las dos regiones metropolitanas. El artículo concluye con una discusión sobre la relevancia de los resultados y una reflexión sobre la agenda futura de estudios sobre segregación urbana.
ABSTRACT
Local delivery of antibiotics has gained increasing interest in the treatment of osteomyelitis due to its effectiveness and safety. Since the regeneration of bone tissue at the site of infection is as important as bacterial eradication, implantable drug delivery systems should not only release the drugs in a proper manner but also exert the osseointegration capability. Herein, we present an implantable drug delivery system in a scaffold form with a unique set of features for local treatment of osteomyelitis. For the first time, collagen type I, ciprofloxacin-loaded mesoporous silica, and bioglass were combined to obtain scaffolds using the molding method. Drug-loaded mesoporous silica was blended with polydimethylsiloxane to prolong the drug release, whereas bioglass served as a remineralization agent. Collagen-silica scaffolds were evaluated in terms of physicochemical properties, drug release rate, mineralization potential, osteoblast response in vitro, antimicrobial activity, and biological properties using an in vivo preclinical model - chick embryo chorioallantoic membrane (CAM). The desirable multifunctionality of the proposed collagen-silica scaffolds was confirmed. They released the ciprofloxacin for 80 days, prevented biofilm development, and induced hydroxyapatite formation. Moreover, the resulting macroporous structure of the scaffolds promoted osteoblast attachment, infiltration, and proliferation. Collagen-silica scaffolds were also biocompatible and effectively integrated with CAM.
Subject(s)
Anti-Bacterial Agents , Osteomyelitis , Chick Embryo , Animals , Anti-Bacterial Agents/pharmacology , Tissue Scaffolds/chemistry , Silicon Dioxide/chemistry , Drug Delivery Systems , Collagen/chemistry , Bone and Bones , Ciprofloxacin/pharmacology , Osteomyelitis/drug therapy , Porosity , Biocompatible Materials/chemistry , Bone RegenerationABSTRACT
BACKGROUND: Vaginal birth is a risk factor for weakening of the pelvic floor muscles (PFM) and development of pelvic floor dysfunction (PFD). Perineal tears may decrease PFM function. PFM tone can be assessed with surface EMG (sEMG), but reliability studies of sEMG in women with perineal tears are lacking. The aims of this study were to evaluate test-retest and intrarater reliability of sEMG and compare PFM activation between nulliparous and primiparous. METHODS: A sEMG test-retest was performed in 21 women (12 nulliparous and 9 primiparous with grade II tears) to assess intra-rater reliability during rest and maximal voluntary contraction (MVC) of the PFM. Intraclass Correlation Coefficient (ICC), standard error of measurement (SEM) and minimal detectable change (MDC) were tested. A comparison between nulliparous' and primiparous' PFM activation during rest and MVC was performed. RESULTS: sEMG demonstrated fair reliability in nulliparous (ICC: 0.239; SEM: 5.2; MDC: 14.5) and moderate reliability in primiparous (ICC: 0.409; SEM: 1.5; MDC: 4.2) during rest. For peak MVC very good intrarater reliability was found in nulliparous (ICC: 0.92; SEM: 8.0; MDC: 22.2) and in primiparous (ICC: 0.823; SEM: 8.0; MDC: 22.2). Statistically significant lower PFM activation was found in primiparous women with perineal tear grade II than in nulliparous at rest (mean difference 9.1 µV, 95% confidence interval [CI] 3.0-19.0, p = 0.001), and during MVCpeak (mean difference 50.0 µV, 95% CI 10.0-120.0 p = 0.021). CONCLUSIONS: sEMG is reliable when measuring PFM activation in primiparous women with perineal tears grade II. Women with perineal tears grade II have lower PFM activation both during rest and MVC.
Subject(s)
Muscle Contraction , Pelvic Floor Disorders , Female , Humans , Electromyography , Muscle Contraction/physiology , Pelvic Floor , Reproducibility of ResultsABSTRACT
OBJECTIVE: Compare the neonatal outcomes of two protocols of diagnosis and surveillance of pregnancies complicated by early-onset FGR in a tertiary hospital. METHODS: This is a retrospective cohort study of pregnant women diagnosed with early-onset FGR between 2017 and 2020. We compared the obstetric and perinatal outcomes between two different management protocols (before and after 2019). RESULTS: Seventy-two cases of early-onset FGR were diagnosed in the forementioned period: 45 (62.5%) were managed according to protocol 1 and 27 (37.5%) according to protocol 2. Mean gestational age at delivery was significantly different between groups: 34.9 ± 3.1 weeks (95% CI 34.0-35.9) in group 1 and 32.3 ± 4.4 weeks (95% CI 30.4-33.9) in group 2. 74.1% (20) of newborns in group 2 were admitted in de NICU, a significant difference when compared with 46.7% of group 1. There were no statistically significant differences in the remaining serious neonatal adverse outcomes. CONCLUSIONS: This is the first study published comparing two different protocols of management of FGR. The implementation of the new protocol seems to have led to a decrease in the number of fetuses labeled as growth restricted and to a decrease in the gestational age of delivery of such fetuses, but without increasing the rate of serious neonatal adverse outcomes. SYNOPSIS: The implementation of the 2016 ISUOG guidelines for the diagnosis of fetal growth restriction seems to have led to a decrease in the number of fetuses labeled as growth restricted and to a decrease in the gestational age of delivery of such fetuses, but without increasing the rate of serious neonatal adverse outcomes.
Subject(s)
Fetal Growth Retardation , Fetus , Infant, Newborn , Pregnancy , Humans , Female , Infant , Retrospective Studies , Gestational Age , HospitalizationABSTRACT
The nanostructured lanthanide-silica materials of the Ln-SiO2 type (Ln = La, Ce, Pr, Nd, Eu, Gd, Dy, Yb, Lu) were synthesized by the hydrothermal method at 100 °C, using cetyltrimethylammonium as a structural template, silica gel and sodium silicate as a source of silicon, and lanthanide oxides, with Si/Ln molar ratio = 50. The resulting materials were calcined at 500 °C using nitrogen and air, and characterized by X-ray diffraction (XRD), Fourier-Transform infrared absorption spectroscopy, scanning electron microscopy, thermogravimetry (TG), surface area by the BET method and acidity measurements by n-butylamine adsorption. The XRD and chemical analysis indicated that the SiO2 presented a hexagonal structure and the incorporation of lanthanides in the structure changes the properties of the Ln-SiO2 materials. The heavier the lanthanide element, the higher the Si/Ln ratio. The TG curves showed that the decomposition of the structural template occurs in the materials at temperatures below 500 °C. The samples showed variations in specific surface area, mean pore diameter and silica wall thickness, depending on the nature of the lanthanide. The incorporation of different lanthanides in the silica generated acid sites of varied strength. The hydrothermal stability of the Ln-SiO2 materials evaluated at high temperatures, evidenced that the properties can be controlled for application in adsorption and catalysis processes.
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INTRODUCTION: The aim of this study was to evaluate the accuracy of 35-37 weeks' ultrasound for fetal growth restriction (FGR) detection and the impact of 30th-33rd weeks versus 30th-33rd and 35th-37th weeks' ultrasound on perinatal outcomes. METHODS: This was a randomized controlled trial that enrolled 1,061 low-risk pregnant women: 513 in the control group (routine ultrasound performed at 30th-33rd weeks) and 548 in the study group (with an additional ultrasound at 35th-37th weeks). FGR was defined as a fetus with an estimated fetal weight (EFW) below the 10th percentile. p values < 0.05 were considered statistically significant. RESULTS: The ultrasound at 35-37 weeks had an overall accuracy of FGR screening of 94%. Spearman's correlation coefficient between EFW and birthweight centile was higher for at 35-37 weeks' ultrasound (ρ = 0.75) compared with 30-33 weeks' ultrasound (ρ = 0.44). The study group had a lower rate of operative vaginal deliveries (24.4% vs. 39.3%, p = 0.005) and cesarean deliveries for nonreassuring fetal status (16.8% vs. 38.8%, p < 0.001). DISCUSSION/CONCLUSION: A later ultrasound (35-37 weeks) had a high accuracy for detection of FGR and had a higher correlation between EFW and birthweight centiles. Furthermore, it was also associated with lower adverse perinatal outcomes compared to an earlier ultrasound.
Subject(s)
Infant, Small for Gestational Age , Ultrasonography, Prenatal , Infant, Newborn , Pregnancy , Female , Humans , Birth Weight , Pregnancy Trimester, Third , Fetal Growth Retardation/diagnostic imaging , Fetal Weight , Parturition , Gestational AgeABSTRACT
The development and approval of new treatments generates large volumes of results, such as summaries of efficacy and safety. However, it is commonly overlooked that analyzing clinical study data also produces data in the form of results. For example, descriptive statistics and model predictions are data. Although integrating and putting findings into context is a cornerstone of scientific work, analysis results are often neglected as a data source. Results end up stored as "data products" such as PDF documents that are not machine readable or amenable to future analyses. We propose a solution to "calculate once, use many times" by combining analysis results standards with a common data model. This analysis results data model re-frames the target of analyses from static representations of the results (e.g., tables and figures) to a data model with applications in various contexts, including knowledge discovery. Further, we provide a working proof of concept detailing how to approach standardization and construct a schema to store and query analysis results.
Subject(s)
Information Storage and Retrieval , Clinical Studies as TopicABSTRACT
One of the most serious complications following the implantation of orthopedic biomaterials is the development of infection. Orthopedic implant-related infections do not only entail clinical problems and patient suffering, but also cause a burden on healthcare care systems. Additionally, the ageing of the world population, in particular in developed countries, has led to an increase in the population above 60 years. This is a significantly vulnerable population segment insofar as biomaterials use is concerned. Implanted materials are highly susceptible to bacterial and fungal colonization and the consequent infection. These microorganisms are often opportunistic, taking advantage of the weakening of the body defenses at the implant surface-tissue interface to attach to tissues or implant surfaces, instigating biofilm formation and subsequent development of infection. The establishment of biofilm leads to tissue destruction, systemic dissemination of the pathogen, and dysfunction of the implant/bone joint, leading to implant failure. Moreover, the contaminated implant can be a reservoir for infection of the surrounding tissue where microorganisms are protected. Therefore, the biofilm increases the pathogenesis of infection since that structure offers protection against host defenses and antimicrobial therapies. Additionally, the rapid emergence of bacterial strains resistant to antibiotics prompted the development of new alternative approaches to prevent and control implant-related infections. Several concepts and approaches have been developed to obtain biomaterials endowed with anti-infective properties. In this review, several anti-infective strategies based on biomaterial engineering are described and discussed in terms of design and fabrication, mechanisms of action, benefits, and drawbacks for preventing and treating orthopaedic biomaterials-related infections.
Subject(s)
Anti-Infective Agents , Orthopedics , Anti-Bacterial Agents/chemistry , Anti-Infective Agents/pharmacology , Anti-Infective Agents/therapeutic use , Bacteria , Biocompatible Materials/chemistry , Biocompatible Materials/therapeutic use , Bioengineering , Biofilms , Humans , Prostheses and Implants/adverse effectsABSTRACT
Recent theoretical and methodological advances in activity space and big data provide new opportunities to study socio-spatial segregation. This review first provides an overview of the literature in terms of measurements, spatial patterns, underlying causes, and social consequences of spatial segregation. These studies are mainly place-centred and static, ignoring the segregation experience across various activity spaces due to the dynamism of movements. In response to this challenge, we highlight the work in progress toward a new paradigm for segregation studies. Specifically, this review presents how and the extent to which activity space methods can advance segregation research from a people-based perspective. It explains the requirements of mobility-based methods for quantifying the dynamics of segregation due to high movement within the urban context. It then discusses and illustrates a dynamic and multi-dimensional framework to show how big data can enhance understanding segregation by capturing individuals' spatio-temporal behaviours. The review closes with new directions and challenges for segregation research using big data.
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OBJECTIVE: This study aimed to assess the efficacy of sonographic assessment of fetal occiput position before operative vaginal delivery to decrease the number of failed operative vaginal deliveries. DATA SOURCES: The search was conducted in MEDLINE, Embase, Web of Science, Scopus, ClinicalTrial.gov, Ovid, and Cochrane Library as electronic databases from the inception of each database to April 2021. No restrictions for language or geographic location were applied. STUDY ELIGIBILITY CRITERIA: Selection criteria included randomized controlled trails of pregnant women randomized to either sonographic or clinical digital diagnosis of fetal occiput position during the second stage of labor before operative vaginal delivery. METHODS: The primary outcome was failed operative vaginal delivery, defined as a failed fetal operative vaginal delivery (vacuum or forceps) extraction requiring a cesarean delivery or forceps after failed vacuum. The summary measures were reported as relative risks or as mean differences with 95% confidence intervals using the random effects model of DerSimonian and Laird. An I2 (Higgins I2) >0% was used to identify heterogeneity. RESULTS: A total of 4 randomized controlled trials including 1007 women with singleton, term, cephalic fetuses randomized to either the sonographic (n=484) or clinical digital (n=523) diagnosis of occiput position during the second stage of labor before operative vaginal delivery were included. Before operative vaginal delivery, fetal occiput position was diagnosed as anterior in 63.5% of the sonographic diagnosis group vs 69.5% in the clinical digital diagnosis group (P=.04). There was no significant difference in the rate of failed operative vaginal deliveries between the sonographic and clinical diagnosis of occiput position groups (9.9% vs 8.2%; relative risk, 1.14; 95% confidence interval, 0.77-1.68). Women randomized to sonographic diagnosis of occiput position had a significantly lower rate of occiput position discordance between the evaluation before operative vaginal delivery and the at birth evaluation when compared with those randomized to the clinical diagnosis group (2.3% vs 17.7%; relative risk, 0.16; 95% confidence interval, 0.04-0.74; P=.02). There were no significant differences in any of the other secondary obstetrical and perinatal outcomes assessed. CONCLUSION: Sonographic knowledge of occiput position before operative vaginal delivery does not seem to have an effect on the incidence of failed operative vaginal deliveries despite better sonographic accuracy in the occiput position diagnosis when compared with clinical assessment. Future studies should evaluate how a more accurate sonographic diagnosis of occiput position or other parameters can lead to a safer and more effective operative vaginal delivery technique.
Subject(s)
Labor Presentation , Ultrasonography, Prenatal , Delivery, Obstetric , Female , Humans , Infant, Newborn , Pregnancy , Randomized Controlled Trials as Topic , UltrasonographyABSTRACT
Pulmonary drug delivery has recognized benefits for both local and systemic treatments. Dry powder inhalers (DPIs) are convenient, portable and environmentally friendly devices, becoming an optimal choice for patients. The tailoring of novel formulations for DPIs, namely in the form of porous particles, is stimulating in the pharmaceutical research area to improve delivery efficiency. Suitable powder technological approaches are being sought to design such formulations. Namely, aerogel powders are nanostructured porous particles with particularly attractive properties (large surface area, excellent aerodynamic properties and high fluid uptake capacity) for these purposes. In this review, the most recent development on powder technologies used for the processing of particulate porous carriers are described via updated examples and critically discussed. A special focus will be devoted to the most recent advances and uses of aerogel technology to obtain porous particles with advanced performance in pulmonary delivery.
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INTRODUCTION: The role of intrapartum ultrasound as an ancillary method to instrumental vaginal delivery is yet to be determined. This study aimed to compare the use of transabdominal and transperineal ultrasound with routine clinical care before performing an instrumental vaginal delivery, regarding the incidence of adverse maternal and neonatal outcomes. MATERIAL AND METHODS: A randomized controlled trial was conducted between October 2016 and March 2019 in two tertiary care maternity hospitals in Lisbon, Portugal. Women at term, with full cervical dilatation, singleton fetuses in cephalic presentation, and with an established indication for instrumental vaginal delivery, were approached for enrollment. After informed consent was obtained, randomization into one of two groups was carried out. In the experimental arm, women underwent transabdominal ultrasound for determination of the fetal head position and transperineal ultrasound for evaluation of the angle of progression, before instrumental vaginal delivery. In the control arm, no ultrasound was carried out before instrumental vaginal delivery. Primary outcomes were composite measures of maternal and neonatal morbidity. Composite maternal morbidity consisted of severe postpartum hemorrhage, perineal trauma, and prolonged hospital stay. Composite neonatal morbidity consisted of low 5-minute Apgar score, umbilical artery metabolic acidosis, birth trauma, and neonatal intensive care unit admission. RESULTS: A total of 222 women were enrolled (113 in the experimental arm and 109 in the control arm). No significant differences between the two arms were found in composite measures of maternal (23.9% in the experimental group vs 22.9% in the control group, odds ratio 1.055, 95% CI 0.567-1.964) or neonatal morbidity (9.7% in the experimental group vs 6.4% in the control group, odds ratio 1.571, 95% CI 0.586-4.215), nor in any of the individual outcomes. CONCLUSIONS: In this small randomized controlled trial that was stopped for futility before reaching the required sample size, transabdominal and transperineal ultrasound performed just before instrumental vaginal delivery did not reduce the incidence of adverse maternal and neonatal outcomes, when compared with routine clinical care.
Subject(s)
Labor Presentation , Labor Stage, Second/physiology , Pregnancy Outcome/epidemiology , Ultrasonography, Prenatal/methods , Vacuum Extraction, Obstetrical/methods , Adult , Female , Humans , Infant, Newborn , Obstetric Labor Complications/epidemiology , Pregnancy , Umbilical Arteries/diagnostic imagingABSTRACT
The delivery of bioactive agents using active wound dressings for the management of pain and infections offers improved performances in the treatment of wound complications. In this work, solid lipid microparticles (SLMPs) loaded with lidocaine hydrochloride (LID) were processed and the formulation was evaluated regarding its ability to deliver the drug at the wound site and through the skin barrier. The SLMPs of glyceryl monostearate (GMS) were prepared with different LID contents (0, 1, 2, 4, and 10 wt.%) using the solvent-free and one-step PGSS (Particles from Gas-Saturated Solutions) technique. PGSS exploits the use of supercritical CO2 (scCO2) as a plasticizer for lipids and as pressurizing agent for the atomization of particles. The SLMPs were characterized in terms of shape, size, and morphology (SEM), physicochemical properties (ATR-IR, XRD), and drug content and release behavior. An in vitro test for the evaluation of the influence of the wound environment on the LID release rate from SLMPs was studied using different bioengineered human skin substitutes obtained by 3D-bioprinting. Finally, the antimicrobial activity of the SLMPs was evaluated against three relevant bacteria in wound infections (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa). SLMPs processed with 10 wt.% of LID showed a remarkable performance to provide effective doses for pain relief and preventive infection effects.
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BACKGROUND: Public health surveillance is based on the continuous and systematic collection, analysis, and interpretation of data. This informs the development of early warning systems to monitor epidemics and documents the impact of intervention measures. The introduction of digital data sources, and specifically sources available on the internet, has impacted the field of public health surveillance. New opportunities enabled by the underlying availability and scale of internet-based sources (IBSs) have paved the way for novel approaches for disease surveillance, exploration of health communities, and the study of epidemic dynamics. This field and approach is also known as infodemiology or infoveillance. OBJECTIVE: This review aimed to assess research findings regarding the application of IBSs for public health surveillance (infodemiology or infoveillance). To achieve this, we have presented a comprehensive systematic literature review with a focus on these sources and their limitations, the diseases targeted, and commonly applied methods. METHODS: A systematic literature review was conducted targeting publications between 2012 and 2018 that leveraged IBSs for public health surveillance, outbreak forecasting, disease characterization, diagnosis prediction, content analysis, and health-topic identification. The search results were filtered according to previously defined inclusion and exclusion criteria. RESULTS: Spanning a total of 162 publications, we determined infectious diseases to be the preferred case study (108/162, 66.7%). Of the eight categories of IBSs (search queries, social media, news, discussion forums, websites, web encyclopedia, and online obituaries), search queries and social media were applied in 95.1% (154/162) of the reviewed publications. We also identified limitations in representativeness and biased user age groups, as well as high susceptibility to media events by search queries, social media, and web encyclopedias. CONCLUSIONS: IBSs are a valuable proxy to study illnesses affecting the general population; however, it is important to characterize which diseases are best suited for the available sources; the literature shows that the level of engagement among online platforms can be a potential indicator. There is a necessity to understand the population's online behavior; in addition, the exploration of health information dissemination and its content is significantly unexplored. With this information, we can understand how the population communicates about illnesses online and, in the process, benefit public health.
Subject(s)
Information Dissemination/methods , Public Health Surveillance/methods , Humans , InternetABSTRACT
Biopolymer-based aerogels can be obtained by supercritical drying of wet gels and endowed with outstanding properties for biomedical applications. Namely, polysaccharide-based aerogels in the form of microparticles are of special interest for wound treatment and can also be loaded with bioactive agents to improve the healing process. However, the production of the precursor gel may be limited by the viscosity of the polysaccharide initial solution. The jet cutting technique is regarded as a suitable processing technique to overcome this problem. In this work, the technological combination of jet cutting and supercritical drying of gels was assessed to produce chitosan aerogel microparticles loaded with vancomycin HCl (antimicrobial agent) for wound healing purposes. The resulting aerogel formulation was evaluated in terms of morphology, textural properties, drug loading, and release profile. Aerogels were also tested for wound application in terms of exudate sorption capacity, antimicrobial activity, hemocompatibility, and cytocompatibility. Overall, the microparticles had excellent textural properties, absorbed high amounts of exudate, and controlled the release of vancomycin HCl, providing sustained antimicrobial activity.
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An innovative delivery system based on bacteriophages-loaded alginate-nanohydroxyapatite hydrogel was developed as a multifunctional approach for local tissue regeneration and infection prevention and control. Bacteriophages were efficiently encapsulated, without jeopardizing phage viability and functionality, nor affecting hydrogel morphology and chemical composition. Bacteriophage delivery occurred by swelling-disintegration-degradation process of the alginate structure and was influenced by environmental pH. Good tissue response was observed following the implantation of bacteriophages-loaded hydrogels, sustaining their biosafety profile. Bacteriophages-loaded hydrogels did not affect osteoblastic cells' proliferation and morphology. A strong osteogenic and mineralization response was promoted through the implantation of hydrogels system with nanohydroxyapatite. Lastly, bacteriophages-loaded hydrogel showed excellent antimicrobial activity inhibiting the attachment and colonization of multidrug-resistant E. faecalis surrounding and within femoral tissues. This new local delivery approach could be a promising approach to prevent and control bacterial contamination during implantation and bone integration.
Subject(s)
Alginates/chemistry , Bacteriophages/chemistry , Hydrogels/chemistry , Anti-Infective Agents/chemistry , Bacteriophages/physiology , Cell Proliferation/drug effects , Hydrogen-Ion Concentration , Tissue Engineering , Tissue Scaffolds/chemistryABSTRACT
OBJECTIVES: The objective of this study was to evaluate the effect of simulation-based training on the accuracy of fetal head position determination by junior residents during the second stage of labour. STUDY DESIGN: This prospective study was conducted in a tertiary care university hospital. During an initial period of 12 weeks, 13 junior residents were asked to routinely evaluate fetal head position by digital examination during the second stage of labour, in women with term singletons in cephalic presentation. Digital examination was followed immediately by transabdominal ultrasound to confirm fetal head position, performed by an experienced physician. Following this initial period, all participants attended a workshop where simulation-based training of fetal head position determination was provided. A second 12-week period was subsequently completed, with similar characteristics to the initial one. The accuracy of clinical evaluations was assessed by the percentage of exact evaluations, the percentage of correct evaluations within a 45° error margin, and by Cohen's kappa coefficient of agreement. RESULTS: A total of 83 observations were performed in the initial period of the study and 74 observations were performed in the second period. The accuracy of fetal head position determination during the first period of the study was 59.0% (95% CI 47.7-69.7), k = 0.517 (95%CI 0.391 - 0.635), corresponding to a moderate agreement. Considering a 45° margin of error, accuracy was 71.1% (95% CI 60.1-80.5), k = 0.656 (95% CI 0.538 - 0.763), corresponding to substantial agreement. Following simulation-based training, the accuracy of fetal head position determination was 70.3% (95% CI 58.5-80.3), k = 0.651 (95% CI 0.526 - 0.785), corresponding to a substantial agreement. Considering a 45° margin of error, accuracy was 78.4% (95% CI 67.3-87.1), k = 0.745 (95% CI 0.631 - 0.854), corresponding to a substantial agreement. CONCLUSIONS: Although a trend towards increased accuracy in fetal head position determination was observed after simulation-based training, the difference was not statistically significant. Further studies are needed to clarify the role of simulation-based training for fetal head position determination during residency.