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Background Data access through smartphone applications (apps) has reframed procedure and policy in healthcare, but its impact in trauma remains unclear. Citizen is a free app that provides real-time alerts curated from 911 dispatch data. Our primary objective was to determine whether app alerts occurred earlier than recorded times for trauma team activation and emergency department arrival. Methods Trauma registry entries were extracted from a level one urban trauma center from January 1, 2018 to June 30, 2019 and compared with app metadata from the center catchment area. We matched entries to metadata according to description, date, time, and location then compared metadata timestamps to trauma team activation and emergency department arrival times. We computed percentage of time the app reported traumatic events earlier than trauma team activation or emergency department arrival along with exact binomial 95% confidence interval; median differences between times were presented along with interquartile ranges. Results Of 3,684 trauma registry entries, 209 (5.7%) matched app metadata. App alerts were earlier for 96.1% and 96.2% of trauma team activation and emergency department arrival times, respectively, with events reported median 36 (24–53, IQR) minutes earlier than trauma team activation and 32 (25–42, IQR) minutes earlier than emergency department arrival. Registry entries for younger males, motor vehicle-related injuries and penetrating traumas were more likely to match alerts (P Conclusion Apps like Citizen may provide earlier notification of traumatic events and therefore earlier mobilization of trauma service resources. Earlier notification may translate into improved patient outcomes. Additional studies into the benefit of apps for trauma care are warranted.

Current guidelines and recommendations limiting human exposure to extremely low frequency (ELF) magnetic field (MF) are based on the most reliable acute human neurophysiological exposure responses. However, the currently available perception thresholds are established on small sample size and non-replicated experiments. The current human study aimed to test MF levels leading to mahnetophosphenes perceptions at 20, 50, 60 and 100 Hz. Perception reported button-press were recorded in these 4 frequency groups in 55 randomly assigned magnetic flux density conditions. Results showed a frequency-dependent threshold for initial perception: 2.51 T/s at 20 Hz, 6.28 T/s at 50 Hz, 7.54 T/s at 60 Hz, and 12.57 T/s at 100 Hz; and for the 50% detection rate: 4.73 T/s at 20 Hz, 8.83 T/s at 50 Hz, 10.55 T/s at 60 Hz, and 33.46 T/s at 100 Hz. Since it is a linear correlate of the induced in-situ E-fields, the dB/dt metric was chosen to analyse the the data. It confirmed lower magnetophoshene perception at lower frequencies for a similar in-situ induced E-field.

Although magnetophosphene perception is the most reliable reported effect on acute human neurophysiological responses to extremely low frequency (ELF) magnetic field (MF) exposure, current knowledge is based on small sample size, non-replicated experiments. In this study, we established MF levels triggering magnetophosphenes at 20, 50, 60 and 100 Hz in humans. Magnetophosphene perception and EEG were collected in 55 magnetic flux density conditions randomly delivered in each frequency group (2 experiments, total n=145). Results indicate that threshold values 1) need to be reported as a function of dB/dt instead of flux density, and 2) are frequency-dependent (higher sensitivity to lower frequencies). No clear trend was found in EEG data.

Background: After human epidermis wounding, transepithelial potential (TEP) present in nonlesional epidermis decreases and induces an endogenous direct current epithelial electric field (EEF) that could be implicated in the wound re-epithelialization. Some studies suggest that exogenous electric stimulation of wounds can stimulate healing, although the mechanisms remain to be determined. The Problem: Little is known concerning the exact action of the EEF during healing. The mechanism responsible for TEP and EEF is unknown due to the lack of an in vitro model to study this phenomenon. Basic Science Advances: We carried out studies by using a wound created in a human tissue-engineered skin and determined that TEP undergoes ascending and decreasing phases during the epithelium formation. The in vitro TEP measurements over time in the wound were corroborated with histological changes and with in vivo TEP variations during porcine skin wound healing. The expression of a crucial element implicated in Na+ transp...

Normal human epidermis possesses a transepithelial potential (TEP) that varies in different parts of the body (10–60mV). The role of TEP in normal epidermis is not yet identified; but after skin injury, TEP disruption induces an endogenous direct current electric field (100–200mV/mm) directed toward the middle of the wound. This endogenous electric field could be implicated in the wound healing process by attracting cells, thus facilitating reepithelialization. However, little is known on the restoration of the TEP during human skin formation and wound healing. In this study, the variations in TEP and Na+/K+ ATPase pump expression during the formation of the epithelium were investigated in vitro using human tissue-engineered human skin (TES) reconstituted by tissue engineering and in vivo with a porcine wound healing model. Results showed that TEP undergoes ascending and decreasing phases during epithelium formation in TES as well as during wound repair within TES. Similar results were observed during in vivo reepithelialization of wounds. The ascending and decreasing TEP values were correlated with changes in the expression of Na+/K+ ATPase pump. The distribution of Na+/K+ ATPase pumps also varied according to epidermal differentiation. Taken together, these results suggest that the variations in the expression of Na+/K+ ATPase pump over time and across epidermis would be a determinant parameter of the TEP, dictating a cationic transport during the formation and restoration of the epidermis. Therefore, this study brings a new perspective to understand the formation and restoration of TEP during the cutaneous wound healing process. This might have important future medical applications regarding the treatment of chronic wound healing.

Although a few studies have found that extremely low-frequency (ELF, < 300 Hz) magnetic fields (MF) can modulate human standing balance, the acute effects of electromagnetic fields (EMF) on standing balance have not been systematically investigated. This work aims to establish the threshold for standing balance modulation during ELF MF exposure. One hundred volunteers will be exposed to an ELF MF (0 to 160 Hz, 0 to 100 mT) and stimulated using transcranial electric stimulation (DC and AC, 1 mA). The displacement of their center of pressure will be collected and analyzed using validated sway characteristics to detect modulations of vestibular function. Future protocols will be designed to test for possible effects due to exposures in the radiofrequency range (i.e. above 3 kHz). These results will contribute to the literature documenting exposure guidelines aiming to protect workers and the general public.

The goal of this study was to address some of the factors that contribute to the human ability to detect the presence of weak electric fields generated by direct current (DC) and alternating current (AC) sources. An exposure chamber allowed us to expose a limited surface of the body (forearm and hand) to DC fields of up to 65 kV/m and AC fields up to a maximum of 35 kV/m (frequency 60 Hz). Perception was examined using a staircase procedure and a rating procedure derived from signal detection theory. Sixteen subjects participated in the experiments, and none detected the local DC fields. In contrast, 9/16 subjects were sensitive to local AC electric fields, although detection thresholds (index of sensitivity, d' = 1.0) were widely variable between subjects. When regional exposure was limited to the dorsal forearm, performance was similar to that seen when the forearm and hand were exposed. In contrast, subjects did not reliably detect the AC electric fields when exposure was limited to the hand (either hairy or glabrous skin), although a minority of subjects (3/9) showed some evidence of detecting fields presented to the glabrous palm. Subjects were unable to detect AC electric fields when the hair was removed from the forearm and hand, suggesting that the evoked sensation is mainly dependent on movement of hair located in the exposed region.

This study was designed to provide an experimental validation for a statistical model predicting past or future exposures to magnetic fields (MF) from power lines. The model estimates exposure, combining the distribution of ambient MF in the absence of power lines with the distribution of past or future MF produced by power lines. In the study, validation is carried out by comparing exposures predicted by the model with the actual measurements obtained from a large-scale epidemiological study. The comparison was made for a group of 220 women living near a 735 kV power line. Knowing that the individual arithmetic means of MF exposures follow a log-normal distribution, the Pearson correlation between the log-transformed measured means and the calculated ones was determined and found to be 0.77. Predicted values of MF exposures were slightly lower than measured values. The calculated geometric mean of the group was 0.33 microT, compared to 0.38 microT for the measured geometric mean. The present study shows good agreement between the measured MF exposure of an individual inside a house near a 735 kV line and the MF exposure calculated using a statistical model.

The human skin contains a physiological battery that could be implicated in the healing process, by creating an endogenous electric field. Skin cells undergo morphological changes in response to an external DC electric field (EF). We found that fibroblasts reorient their cell bodies in a manner perpendicular to the EF direction, for normal and above physiological intensities. Actin and tubulin filaments (cytoskeleton proteins) follow the same pattern of reorientation. Keratinocytes tend to elongate in the same direction, although to a lesser extent. The study of the response of human skin cells to an external EF is a first step toward a better understanding of the mechanisms involved in wound healing and eventually toward the improvement of wound repair. La peau humaine contient une batterie physiologique qui pourrait ětre impliquee dans le processus de guerison en produisant un champ electrique (CE) endogene au site de la plaie. Les cellules de la peau subissent des changements morphologiques lorsqu'elles sont soumises a un CE externe. Sous un CE d'intensite physiologique ou plus grand, les fibroblastes eeorientent leurs corps cellulaires de facon perpendiculaire au CE. Les filaments d'actine et de tubuline (proteines du cytosquelette) repondent de la měme facon. De facon moins evidente, les keratinocytes ont aussi tendance a s'allonger dans la měme direction. La reponse des cellules de la peau face a un CE est une premiere etape vers une meilleure comprehension et amelioration du processus de guerison des plaies.

Several animal studies have been carried out at the Institut Armand Frappier (IAF) to determine whether chronic exposure to 60 Hz linearly polarized sinusoidal magnetic fields might increase the risk of cancer development of female Fisher rats. The magnetic field exposure facility was developed to meet the requirements of the study protocol for chronic exposure of large number of animals to field intensities of sham < 0.2 microT, 2 microT, 20 microT, 200 microT, and 2000 microT. At each exposure level, including sham, the animals are distributed in a group of four exposure units. Each exposure unit contains two exposure volumes having uniform distribution of magnetic fields for the animals, while the magnetic field external to the unit falls off rapidly due to the "figure-eight" coil topography used. A program of "shake down" tests, followed by verification and calibration of the exposure facility, was carried out prior to starting the animal experiments. Continuous monitoring of the magnetic field and other environmental parameters was an important part in the overall quality assurance program adopted.

The results of an experimental study, carried out to determine the influence of the proximity of transmission lines on residential magnetic fields, are reported in this paper. Measurements have been made of magnetic field intensities and exposures in 94 houses located near ( 300 m) from 735 kV, 315 kV and 120 kV transmission lines. The experimental data obtained and some basic statistical analysis of the data are presented.

A statistical model, based on Monte Carlo simulation, is proposed in this paper for evaluating the influence of the proximity of transmission lines on the magnetic field intensities and exposures in the residential environment. The proposed model is validated by comparing the results of calculation using the model with experimental data obtained in a related study.

The objective of this study was to assess the ability of humans to detect the presence of DC electric fields and ion currents. An exposure chamber simulating conditions present in the vicinity of high-voltage DC (HVDC) lines was designed and built for this purpose. In these experiments, the facility was used to expose observers to DC electric fields up to 50 kV/m and ion current densities up to 120 nA/m{sup 2}. Forty-eight volunteers (25 women and 23 men) between the ages of 18 and 57 years served as observers. Perception of DC fields was examined by using two psychophysical methods: an adaptive staircase procedure and a rating method derived from signal-detection theory. Subjects completed three different series of observations by using each of these methods; one was conducted without ion currents, and the other two involved various combinations of electric fields and ion currents. Overall, subjects were significantly more likely to detect DC fields as the intensity increased. Observers were able to detect the presence of DC fields alone, but only at high intensities; the average threshold was 45 kV/m. Except in the most sensitive individuals, ion current densities up to 60 nA/m{sup 2} did not significantly facilitate the detectionmore » of DC fields. However, higher ion current densities were associated with a substantial lowering of sensory thresholds in a large majority of observers. Data analysis also revealed large variations in perceptual thresholds among observers. Normative data indicating DC field and ion current intensities that can be detected by 50% of all observers are provided. In addition, for the most sensitive observers, several other detection proportions were derived from the distribution of individual detection capabilities. These data can form the basis for environmental guidelines relating to the design of HVDC lines.« less

A program of secondary utilization of transmission line corridors for recreational, commercial, educational and industrial activities has been in existence at Hydro-Quebec for several years. In the context of studies indicating a possible link between exposure, educational and industrial activities has been in existence at Hydro-Quebec for several years. In the context of studies indicating a possible link between exposure to power frequency magnetic fields and human health, a study has been carried out to determine the exposure of people involved in the different types of secondary-utilization activities in and near transmission line corridors. Results of this study are presented in this paper. >

Although studies have found that extremely low-frequency (ELF, < 300 Hz) magnetic fields (MF) can modulate human standing balance, the acute effects of electromagnetic fields on standing balance have not been systematically investigated. This work aims to establish the threshold for acute standing balance modulation during ELFMF exposure. One hundred volunteers will be exposed to transcranial electric stimulations (Direct Current - DC and Alternating Current - AC, 1 mA) and ELFMF (0 to 160 Hz, 0 to 100 mT). The displacement of their center of pressure will be collected and analyzed as an indicator of vestibular performance. During pilot testing (n=6), we found increased lateral sway with DC, and to a lesser extent, AC exposure. The ELFMF exposure system still needs to be adapted to allow meaningful results. Future protocol design will test for possible effects due to exposures in the radiofrequency range (i.e. above 3 kHz). These results will contribute to the literature documenting exposure guidelines aiming to protect workers and the general public.

The effects of time-varying magnetic fields (MF) on humans have been actively investigated for the past three decades. One important unanswered question is the potential for MF exposure to have acute effects on human biology. Different strategies have been used to tackle this question using various physiological, neurophysiological and behavioral indicators. For example, researchers investigating electroencephalography (EEG) have reported that extremely low frequency (ELF

A direct current (DC) endogenous electric field (EF) is induced in the wound following skin injury. It is potentially implicated in the wound healing process by attracting cells and altering their phenotypes as indicated by the response to an EF of keratinocytes cultured as individual cells. To better define the signalization induced by a direct current electric field (DCEF) in human keratinocytes, we took advantage of an in vitro model more representative of the in vivo situation since it promotes cell–cell interactions and stratification. Human keratinocytes were grown into colonies. Their exposure to a DCEF of physiological intensity induced an increase of intracellular calcium. This variation of intracellular calcium resulted from an extracellular calcium influx and was mediated, at least in part, by the L-type voltage-gated calcium channel. The increase in intracellular calcium in response to a DCEF was however not observed in all the cells composing the colonies. The intracellular calcium increase was only detected in keratinocytes that didn't express involucrin, a marker of differentiated cells. These results indicate that DCEF is able to induce a specific calcium response in poorly differentiated keratinocytes. This study brings a new perspective for the understanding of the signaling mechanism of endogenous EF in reepithelialization, a critical process during skin wound healing. J. Cell. Physiol. 227: 2660–2667, 2012. © 2011 Wiley Periodicals, Inc.

Emergency rooms (ER) are considered the "front door" of hospitals and are facing overcrowding, high intensity of cares, non-optimal design and a quick turnover of patients and personnel. Very few papers in the litterature discussed infection control (IC) measures in ER. This study evaluated the situation of IC in Quebec’s ER.

Introduction Para-aminobenzoic acid (PABA) is widely used as a topical sunscreen to protect the skin from the harmful effects of ultraviolet (UV) light. PABA acts as a UV filter since its ultraviolet absorption extends beyond that of DNA down to about 320 nm. As such, PABA protects the DNA of skin cells from photolysis. However, synergetic side effects of near-UV photoexcited PABA in pyrimidine dimer-repair-deficient E. coli cells have been reported1 and dimer formation of E. coli. DNA has been demonstrated by chemical analysis.2 Similar sensitization has been observed with mammalian cells including mouse lymphoma cell line3 and human skin fibroblasts,4 and in the latter case the formation of pyrimidine dimers was demonstrated. In this study we confirm the involvement of DNA damage in PABA photosensitization of human cells through the extent of sensitization of cells killing by comparing a DNA-repair-deficient with a normal human skin fibroblast cell line.

Several animal studies have been carried out at the Institut Armand Frappier (IAF) to determine whether chronic exposure to 60 Hz linearly polarized sinusoidal magnetic fields might increase the risk of cancer development of female Fisher rats. The magnetic field exposure facility was developed to meet the requirements of the study protocol for chronic exposure of large number of animals to field intensities of sham0.2 microT, 2 microT, 20 microT, 200 microT, and 2000 microT. At each exposure level, including sham, the animals are distributed in a group of four exposure units. Each exposure unit contains two exposure volumes having uniform distribution of magnetic fields for the animals, while the magnetic field external to the unit falls off rapidly due to the "figure-eight" coil topography used. A program of "shake down" tests, followed by verification and calibration of the exposure facility, was carried out prior to starting the animal experiments. Continuous monitoring of the magnetic field and other environmental parameters was an important part in the overall quality assurance program adopted.

The objective of this study was to assess the ability of humans to detect the presence of DC electric field and ion currents. An exposure chamber simulating conditions present in the vicinity of high-voltage DC (HVDC) lines was designed and built for this purpose. In these experiments, the facility was used to expose observers to DC electric fields up to 50 kV/m and ion current densities up to 120 nA/m2. Forty-eight volunteers (25 women and 23 men) between the ages of 18 and 57 years served as observers. Perception of DC fields was examined by using two psychophysical methods: an adaptive staircase procedure and a rating method derived from signal-detection theory. Subjects completed three different series of observations by using each of these methods; one was conducted without ion currents, and the other two involved various combinations of electric fields and ion currents. Overall, subjects were significantly more likely to detect DC fields as the intensity increased. Observers were able to detect the presence of DC fields alone, but only at high intensities; the average threshold was 45 kV/m. Except in the most sensitive individuals, ion current densities up to 60 nA/m2 did not significantly facilitate the detection of DC fields. However, higher ion current densities were associated with a substantial lowering of sensory thresholds in a large majority of observers. Data analysis also revealed large variations in perceptual thresholds among observers. Normative data indicating DC field and ion current intensities that can be detected by 50% of all observers are provided. In addition, for the most sensitive observers, several other detection proportions were derived from the distribution of individual detection capabilities. These data can form the basis for environmental guidelines relating to the design of HVDC lines.

This article analyzes some aspects concerning the introduction of bacteriological theory and practice into Canadian territory from 1870 to 1930. The author begins by presenting the principal explanatory models characterizing the transition period from pre-bacteriological discourse--referring to infectious diseases and surgical infections--to new bacteriological paradigms. He goes on to analyze the different ways in which the germ theory and then bacteriology spread into Canadian territory. The transition periods, where old and new coexisted, reveal a kind of syncretism by physicians in relation to both aetiology of infectious diseases and surgical procedures. The author then shows that there were two distinct phases in the overall context of the history of antiseptic surgery from 1868 to 1890. He demonstrates that the use of antiseptics did not necessarily mean either adherence to Pasteur's postulates on fermentation or strict observance of Listerian methods. Finally, the article expounds on the role played by European institutions in importing bacteriological knowledge and institutionalizing this new discipline in Canadian territory.

The clearance of glucose from saliva was compared with that from spaces located in an intra-oral appliance. The spaces (N = 8) were similar in shape and size to posterior interdental spaces and could be sampled with a microsyringe without removing the appliance from the mouth. The subjects (N = 5) rinsed their mouths with solutions of 5, 10, or 25% glucose. Samples were obtained from a pair of spaces and from saliva at standard intervals and were analyzed for glucose. The rate of glucose clearance was consistently slower from the spaces than from bulk saliva, as shown by higher concentrations and longer clearance times for the spaces. The clearance curves were similar in shape and were rectilinear when the logarithms of the concentrations were plotted against time. The rate of clearance from the spaces appears to be characteristic for an individual, as was also true of salivary clearance.

Six subjects wore intra-oral devices carrying eight bovine enamel blocks which were covered with a layer of S. mutans. They rinsed their mouths for five sec, one min, or multiples of one min with a 5 or 10% glucose (G) solution. Demineralization was measured after 45 min by determining the change in iodide permeability (ΔIp) of the enamel. In addition, saliva samples, taken at intervals during the test, were analyzed for G, and the time of clearance (tc ) was calculated. Demineralization scores (ΔIp) were consistently greater from the 10% than from the 5% G solution. Both solutions produced an increase in ΔIp with an increase in the rinsing time (tr ). The G remaining in saliva after the rinse did not significantly affect ΔIp. The ΔIp scores showed good correlation with the final pH of the S. mutans cell mass, r= -0.77. For each rinse solution, the scores also showed good correlations with tr (r= 0.87 and 0.79) and much weaker correlations with tr + tc (r=0.44 and 0.53). Continuous in vitro exposure to 1, 5, or 10% solutions of sucrose (S) in saliva for 30 min or more caused a linear increase in ΔIp with time with no concentration effects. A linear increase was also observed in vivo when a one-minute mouth-rinse with 10% solution of S was administered every 30 min. The findings indicate that significant demineralization may occur while carbohydrate foods are consumed, and that brushing the teeth or rinsing the mouth after meals may not be as effective against caries as is generally believed.

Fish population densities were measured at various instances from 2 large colonies of double-crested cormorants Phalacrocorax auritus to test the hypothesis that seabirds deplete prey close to their colonies. Fish densities were significantly lower in bays used by cormorants for feeding than in those outside their foraging range. Our findings provide direct evidence for prey depletion, and support Ashmole's (1963)hypothesis that seabird populations are limited by food supplies during the breeding season. ).

The ability of cooked starch (CS) and raw starch (RS)to cause intraoral enamel demineralization was determined by the iodide permeability (Ip) test which registers demineralization of enamel by an inc

A newly-developed intra-oral enamel demineralization test was used to evaluate the effect of supplementation of a 10% sucrose solution with various components on enamel demineralization induced by the sucrose. Five human subjects wore a palatal prosthesis holding eight blocks of subsurface bovine enamel covered with a layer of S. mutans cells. The test involved rinsing with sucrose solution or with sucrose solution supplemented with 0.162 mol/l of different calcium salts or equivalent concentrations of Na-, K-, and Sr salts; rinsing was for one min at times zero and 45 min of the 90-minute test period. Ca-propionate, Ca-acetate, and Ca-levulinate completely inhibited sucrose-induced enamel demineralization; Ca-chloride, Ca-lactate, and Ca-ascorbate gave from 65-75%, and K-acetate, Nalactate, and Sr-lactate 39, 25, and 18% inhibition, respectively. Consideration of the anion dissociation constants and the Ca-anion association constants of the salts suggests that the observed inhibition is caused mainly by common ion effects and, to a lesser extent, by buffer effects.

The rate of salivary glucose clearance was determined in 6 subjects after rinsing with solutions ranging in concentration from 0.3 to 50%. 6 repeated rinses of 10% glucose by 1 subject gave clearance

Six subjects wore intraoral devices carrying bovine enamel blocks covered with a layer of Streptococcus mutans. They swished solutions of 5% glucose or maltose, or sols or gels of 3, 5, 10, 15, or 20% gelatinized wheat starch in the mouth for 3 X 1 min. Demineralization was measured after 45 min by determining the change in iodide permeability (delta Ip) of the enamel. Spittings of the administered materials and samples of saliva, taken at intervals during the test, were analyzed for maltose, and the time of clearance was calculated. Demineralization was greatest for glucose followed by maltose, the starch gels, and the sols. The latter gave close to zero scores. The salivary clearance time increased with increase in concentration of the starch. Although the starch was hydrolyzed rapidly in the mouth, its oral retentiveness was greater than that of the maltose rinse. Demineralization was closely correlated with the final pH of the S. mutans cell layer. The data indicate that the starch in baked or cooked foods may have a significant demineralization potential and that it enhances oral retentiveness.

Leukemias and their bone marrow microenvironment are known to undergo dynamic changes over the course of disease. However, relatively little is known about the circulation kinetics of leukemia cells, nor the impact of specific factors on the clearance of circulating leukemia cells (CLCs) from the blood. To gain a basic understanding of leukemia cell dynamics over the course of disease progression and therapeutic response, we apply a blood exchange method to mouse models of acute leukemia. We find that CLCs circulate in the blood for 1-2 orders of magnitude longer than solid tumor circulating tumor cells. We further observe that: i) leukemia presence in the marrow can limit the clearance of CLCs in a model of acute lymphocytic leukemia (ALL), and ii) CLCs in a model of relapsed acute myeloid leukemia (AML) can clear faster than their untreated counterparts. Our approach can also directly quantify the impact of microenvironmental factors on CLC clearance properties. For example, data from two leukemia models suggest that E-selectin, a vascular adhesion molecule, alters CLC clearance. Our research highlights that clearance rates of CLCs can vary in response to tumor and treatment status and provides a strategy for identifying basic processes and factors that govern the kinetics of circulating cells.