Bacterial biofilms are presented in many different environments causing a wide variety of infectious processes. Biofilms at their mature stage are difficult to eradicate because of their inherent ...resistance to antimicrobial agents. Easy-to-integrate and in situ detection tools would provide early detection of bacterial presence allowing efficient prophylactic actions. Impedance microbiology has been postulated as a suitable technique that allows monitoring of bacterial biofilm growths in real time. In this work four different culturing setups were developed as testing platforms for measuring real time microbiological cultures that could mimic real field environments. Results suggest that the position of the sensors in regard to the dynamic conditions of the culture might affect the sensitivity and the target parameter. Capacitance and resistance are associated to different biological effects, surface coating and conductivity changes respectively. Relative variations of electrical parameters were recorded in the lab obtaining significant changes in few hours post-infection. It has been proven that biological coating cause largest variations in capacitance, up to 60%, while metabolic activity affects more the resistance giving a variation up to 15%. Fitting analysis has confirmed experimental results showing also the effect of the dead/alive ratio.
Summary
This study examined trends in overweight among women of reproductive age by educational level in 33 low‐ and middle‐income countries, and estimated the contribution of parity, age at first ...birth and breastfeeding to these trends. We used repeated cross‐sectional Demographic Health Surveys of 255,828 women aged 25–49 years interviewed between 1992 and 2009. We applied logistic regression to model overweight (>25 kg m−2) as a function of education, reproductive variables and time period by country and region. The prevalence of overweight ranged from 3.4% in South and Southeast Asia to 73.7% in North Africa West/Central Asia during the study period. The association between education and overweight differed across regions. In North Africa West/Central Asia and Latin American, lower education was associated with higher overweight prevalence, while the inverse was true in South/Southeast Asia and Sub‐Saharan Africa. In all regions, there was a consistent pattern of increasing overweight trends across all educational groups. Older age at first birth, longer breastfeeding and lower parity were associated with less overweight, for differences by educational level in overweight prevalence and trends.
Bacterial biofilms are a common cause of persistent and chronic infections, mostly related to implantable devices. In this context, Staphylococcus species are the most relevant microorganisms ...involved in causing high costs for the healthcare system. New diagnostic and/or therapeutic tools should be developed by providing in vivo analysis of the specific physiological parameters directly related to the status of the indwelling device. Monitoring the biofilm's biological evolution will allow an earlier diagnostic. Impedance microbiology is suggested as a proper technique for directly measuring the development of bacterial biofilms generated inside intravascular catheters. In this study we propose interdigitated microelectrode biosensors be integrated within those implantable devices. In vitro assays have been carried out in order to characterize this methodology as a detection and monitoring tool for bacterial biofilm development. Impedance spectroscopy (IS) was implemented in 96-well microtiter plates, leading to positive results in detecting and monitoring bacterial biofilm development. Two Staphylococcus aureus and two Staphylococcus epidermidis strains were successfully monitored during a 20-h culture, and results show that the low range of the frequency is the most suitable setting for measuring the maximum relative changes.
Lab on a chip (LOC) systems provide interesting and low-cost solutions for key studies and applications in the biomedical field. Along with microfluidics, these microdevices make single-cell ...manipulation possible with high spatial and temporal resolution. In this work we have designed, fabricated and characterized a versatile and inexpensive microfluidic platform for on-chip selective single-cell trapping and treatment using laminar co-flow. The combination of co-existing laminar flow manipulation and hydrodynamic single-cell trapping for selective treatment offers a cost-effective solution for studying the effect of novel drugs on single-cells. The operation of the whole system is experimentally simple, highly adaptable and requires no specific equipment. As a proof of concept, a cytotoxicity study of ethanol in isolated hepatocytes is presented. The developed microfluidic platform controlled by means of co-flow is an attractive and multipurpose solution for the study of new substances of high interest in cell biology research. In addition, this platform will pave the way for the study of cell behavior under dynamic and controllable fluidic conditions providing information at the individual cell level. Thus, this analysis device could also hold a great potential to easily use the trapped cells as sensing elements expanding its functionalities as a cell-based biosensor with single-cell resolution.
•Laminar co-flow based microdevice allows selective treating of single-cells.•Calibration curves for easily controlling the selective on-chip manipulation of single-cells.•Cytotoxicity study of ethanol in isolated hepatocytes is presented.•Potential tool for performing versatile tests for drug discovery and cell therapy.•The whole system may open new strategies for cell-based biosensors with single-cell resolution.
•Brettanomyces bruxellensis has been described as one of the most relevant spoilage yeast in beverages.•Experimental procedures were performed mimicking conditions of the real field.•Interdigitated ...microelectrodes sensors showed a good response to microbiological development.•Impedance spectroscopy analysis suggested that the low frequency range provides the highest sensitivity.
Brettanomyces bruxellensis is considered one of the most relevant spoilage yeasts in the production of alcoholic beverages, especially for wine and cider. During fermentation and later storage, these yeasts can cause changes in the characteristics of the product, ruining the aroma and taste. The presence of Brettanomyces causes a decrease in the quality of the final products and important economic losses. The current work presents a detection method based on impedance spectroscopy analysis using label-free interdigitated microelectrode (IDE) based sensors for spoilage yeast detection. Different conditions (static and stirring) were tested in Brettanomyces cultures inside reactors in order to evaluate the growth behavior. Our results indicate a faster response and an 8% increase of the relative variation of the impedance under stirring condition due to biofilm formation onto the surface of the sensors. Equivalent circuit analysis also confirmed that the difference was caused by the larger biofilm formation under dynamic conditions. The results suggest that this technology could be applied for the early detection of spoilage yeast in wine and cider industries, providing more efficient methods to achieve a higher quality of the final products.
To assess the impact of the addition of 12 maternity leave (ML) weeks (2011), a pay for performance (P4P) exclusive breastfeeding (EBF) promotion strategy (2015), and the COVID-19 pandemic in EBF ...inequalities in Chile.
Interrupted time-series analyses (ITSAs).
Aggregated national EBF data by municipality and month were collected from 2009 to 2020. We assess the impact of the three events in EBF inequalities using two procedures: 1. ITSA stratified by municipal SES quintiles (Q1-Q5); 2. Calculating the EBF slope index of inequality (SII).
The EBF prevalence was higher in lower SES municipalities before and after the three time-events. No impact in EBF inequalities was observed after the extended ML. The P4P strategy increased EBF at six months in all SES quintiles (effect size between 4% and 5%), but in a higher level in poorer municipalities (SII: −0.36% and −1.05%). During COVID-19, wealthier municipalities showed a slightly higher EBF at six months prevalence (SII: 1.44%).
The null impact of the extended ML in EBF inequalities could be explained by a low access to ML among affiliated to the public health system (20%). The P4P strategy includes multiple interventions that seemed effective in increasing EBF across all SES quintiles, but further in lower quintiles. The restrictions in healthcare access in poorer municipalities could explain EBF inequalities during COVID-19.
Purpose
The purpose of this study is to investigate whether there is an association between anticholinergic burden and mortality or rehospitalization in older adults discharged from hospital.
Methods
...Prospective multicenter cohort study carried out with patients aged 65 and older discharged from seven acute care hospitals. The primary outcomes of the study were rehospitalization and mortality within 1 year after discharge. The study population was classified in three groups according to the anticholinergic exposure measured by the Anticholinergic Risk Scale (ARS) and Durán’s list at the time of hospital discharge: without risk (ARS/Durán = 0), low risk (ARS/Durán = 1), and high risk (ARS/Durán ≥ 2). Predictors of hospitalizations and mortality were examined using regression models adjusting for important covariates.
Results
The mean age of the 921 participants was 81.2 years (SD = 7.4 years). Prevalence of exposure to medications with anticholinergic activity ranged from 19.6% with ARS to 32.1% with Durán’s list. During the follow-up period, 30.4% of participants were hospitalized and 19.4% died. Multivariate regression analysis showed that low anticholinergic burden quantified according to Durán’s list was significantly associated with all-cause mortality (OR 1.69, 95% CI 1.02–2.82). This association was not present after adjustment when using ARS. No statistically significant association was found between anticholinergic burden and hospitalizations.
Conclusions
Taking medications with anticholinergic activity is associated with greater risk of mortality in older adults discharged from acute care hospitals. Strategies to reduce anticholinergic burden in vulnerable elders could be useful to improve health outcomes. Further research is required to assess the association between anticholinergic burden and hospitalizations in older patients.
Cancer is a leading cause of mortality in the world, with osteosarcoma being one of the most common types among children between 1 and 14 years old. Current treatments including preoperative ...chemotherapy, surgery and postoperative chemotherapy produce several side effects with limited effectiveness. The use of lipid nanoparticles as biodegradable shells for controlled drug delivery shows promise as a more effective and targeted tumor treatment. However,
in vitro
validation of these vehicles is limited due to fluid stagnation in current techniques, in which nanoparticles sediment onto the bottom of the wells killing the cells by asphyxiation. In the current series of experiments, results obtained with methotrexate-lipid nanoparticles under dynamic assay conditions are presented as a promising alternative to current free drug based therapies. Effects on the viability of the U-2 OS osteosarcoma cell line of recirculation of cell media, free methotrexate and blank and methotrexate containing lipid nanoparticles in a 11 μM concentration were successfully assessed. In addition, several designs for the microfluidic platform used were simulated using COMSOL-Multiphysics, optimized devices were fabricated using soft-lithography and simulated parameters were experimentally validated. Nanoparticles did not sediment to the bottom of the platform, demonstrating the effectiveness of the proposed system. Moreover, encapsulated methotrexate was the most effective treatment, as after 72 h the cell population was reduced nearly 40% while under free methotrexate circulation the cell population doubled. Overall, these results indicate that methotrexate-lipid nanoparticles are a promising targeted therapy for osteosarcoma treatment.
Background Our sense of body ownership is profound and familiar, yet it may be misleading. In the rubber-hand illusion, synchronous tactile and visual stimulation lead to the experience that a rubber ...hand is actually one's own. This illusion is stronger in schizophrenia. Given the evidence that ketamine, a noncompetitive N -methyl-D-aspartate antagonist reproduces symptoms of schizophrenia, we sought to determine whether the rubber-hand illusion is augmented by ketamine. Methods We studied 15 healthy volunteers in a within-subjects placebo-controlled study. All volunteers carried out two versions of the rubber-hand task, each under both placebo and ketamine infusions. In one task, they saw a rubber hand being stroked in synchrony with tactile stimulation of their real, hidden hand. In the other, stroking of the real and rubber hands was asynchronous. We recorded subjective changes in sense of ownership, as well as participants' ability to localize their hidden hand. Results Ketamine was associated with significant increases in subjective measures of the illusion and in hand mislocalization. Although asynchronous visuotactile stimulation attenuates the strength of the illusion during both placebo and ketamine, there remained a significant illusory effect during asynchronous visuotactile stimulation under ketamine compared with placebo. The strength of the illusion during asynchronous visuotactile stimulation correlated with other subjective effects of the drug. Conclusions Ketamine mimics the perturbed sense of body ownership seen in schizophrenia, suggesting that it produces a comparable alteration in integration of information across sensory domains and in the subjective and behavioral consequences of such integration.
•Interdigitated microelectrodes biosensors were employed to analyze the temperature and pH shift in impedance measurements.•A novel impedance mathematical model was developed and validated.•The ...influence of different parameters (sensor’s design, temperature, pH and frequency) were evaluated on impedance.•Impedance measurements were corrected from temperature and pH effects.
Impedance spectroscopy analysis (IS) has awakened a great interest for many industrial applications and sectors for the implementation of novel monitoring capabilities. More specifically, microelectrode-based sensors are increasingly being used to analyze electrical or electrochemical changes in liquid samples, as well as other effects such as biofouling, particle adhesion, etc. However, real environmental conditions are usually subjected physiochemical changes that affect the impedance measurement. In this context, it is difficult to isolate the effect of only one parameter (i.e., conductivity of the medium) from the other ones. This work is focused specifically on the analysis of the influence of temperature and pH on the impedance measurements. Different experiments were carried out using interdigitated microelectrodes (IDE) sensors for a geometry range in wine samples to adjust a proposed mathematical model of the impedance behavior. In the case of fermentation processes of alcoholic beverages, this methodology will help to isolate the chemical changes measured by impedance from temperature or pH variation. This model also provides the significance of the effect of each parameter on the impedance values. After the experimental validation, the model was used to correct the impedance values accordingly to the variation of each parameter showing its applicability to the real field. Finally, the proposed methodology can be easily applied and extended to other environments and sensors types.
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