The impact of global health outreach experiences on medical student burnout.

BACKGROUND: Student burnout during medical education is a prevalent and critical problem. Burnout has reaching consequences, including negative health outcomes for students, financial loss for schools, and worsened patient care as students transition to practice. Global Health Outreach Experiences (GHOEs), known to enhance cultural awareness and clinical knowledge among medical students, are offered in most programs. Prior studies document that GHOEs benefit physicians suffering from burnout, with effects demonstrating improvement over 6 months. No study, to our knowledge, has assessed the influence GHOEs may have on medical student burnout with a comparable control group. This study examines whether participation in a GHOE, compared to a standard break from school, has a positive effect on burnout. METHODS: A case control study utilizing the Copenhagen Burnout Inventory was conducted on medical students. 41 students participated in a one-week, spring break GHOE and 252 were randomly selected as non-participating students in a control group. Assessments were gathered 1 week prior, 1 week after, and 10 weeks after spring break. Response across the surveys in chronological order included 22, 20, 19 GHOE and 70, 66, 50 control participants. RESULTS: A significant reduction in personal burnout (PB) (P = 0.0161), studies related burnout (SRB) (P = 0.0056), and colleagues related burnout (CRB) (P = 0.0357) was found among GHOE attendees compared to control participants at 10-weeks after spring break. When modeled with potential confounders, CRB and SRB reductions remained significant. CONCLUSION: GHOEs may be a potential tool for institutions to combat burnout rates in their students. The benefits of GHOEs appear to enhance over time.

Detection of Airborne Nanoparticles through Enhanced Light Scattering Images.

A new method is proposed in this paper to detect airborne nanoparticles, detecting the light scattering caused by both the particle and the surrounding molecules, which can surpass the limitations of conventional laser optical methods while maintaining simplicity and cost-effectiveness. This method is derived from a mathematical analysis that describes the particle light scattering phenomenon more exactly by including the influence of light scattered from surrounding gas molecules. The analysis shows that it is often too much of a simplification to consider only light scattering from the detected nanoparticle, because light scattering from the surrounding gas molecules, whether visible or invisible to the sensor, is important for nanoparticle detection. An image detection approach utilizing the light scattering from surrounding air molecules is described for the detection of airborne nanoparticles. Tests using monodisperse nanoparticles confirm that airborne particles of around 50 nm in size can even be detected using a low-cost testing device. This shows further that even when using a simple image processing code, captured particle light scattering images can be converted digitally into instantaneous particle counts or concentrations. The factors limiting conventional pulse detection are further discussed. This new method utilizes a simple static light scattering (SLS) approach to enable the development of new devices with better detection capabilities, paving the way for the further development of nanoparticle detection technology.

Quantitative analysis of droplet deposition produced by an electrostatic sprayer on a classroom table by using fluorescent tracer.

Due to the ongoing COVID-19 pandemic situation, measures to mitigate the risk of transmission of the SARS-CoV-2 virus in an indoor setting are urgently needed. Among the various types of disinfectant methods, electrostatic spraying is often applied to decontamination in public places. For quantitatively characterizing electrostatic spraying, we developed the novel evaluation method by using a fluorescent tracer. By applying this method, we performed three different experiment cases (static test on a table, static test on a cylinder, and dynamic test on a table) to figure out its unique characteristics (Coulombic fission and wraparound effect) and measure its performance in various aspects. To be specific, bimodal distribution with peak sizes of ~10 and ~100 µm was found due to Coulombic fission. Otherwise, a unimodal distribution with a peak size of ~100 µm occurred for the uncharged droplets. As a result, the effective contact area increased by 40-80 % due to small progeny droplets. The wraparound effect was examined on two different cylinders: copper (Cu) and polyvinyl chloride (PVC) pipe. When the target surface was not charged (Cu 0 kV and PVC 0 kV), the average normalized concentrations on the backside of the cylinder (θ = 180°) increased by around 67 % for charged droplets. Meanwhile, when the target surface was highly charged (PVC -19 kV), the average normalized concentrations at θ = 180° were increased more than two times for charged droplets.

Correction to: Ancestral Folate Promotes Neuronal Regeneration in Serial Generations of Progeny.

The original version of this article unfortunately contained error in Figure 4a to where some of the text was overlapping.

Ancestral Folate Promotes Neuronal Regeneration in Serial Generations of Progeny.

Folate supplementation in F0 mating rodents increases regeneration of injured spinal axons in vivo in 4 or more generations of progeny (F1-F4) in the absence of interval folate administration to the progeny. Transmission of the enhanced regeneration phenotype to untreated progeny parallels axonal growth in neuron culture after in vivo folate administration to the F0 ancestors alone, in correlation with differential patterns of genomic DNA methylation and RNA transcription in treated lineages. Enhanced axonal regeneration phenotypes are observed with diverse folate preparations and routes of administration, in outbred and inbred rodent strains, and in two rodent genera comprising rats and mice, and are reversed in F4-F5 progeny by pretreatment with DNA demethylating agents prior to phenotyping. Uniform transmission of the enhanced regeneration phenotype to progeny together with differential patterns of DNA methylation and RNA expression is consistent with a non-Mendelian mechanism. The capacity of an essential nutritional co-factor to induce a beneficial transgenerational phenotype in untreated offspring carries broad implications for the diagnosis, prevention, and treatment of inborn and acquired disorders.

Gut microbiome identifies risk for colorectal polyps.

OBJECTIVE: To characterise the gut microbiome in subjects with and without polyps and evaluate the potential of the microbiome as a non-invasive biomarker to screen for risk of colorectal cancer (CRC). DESIGN: Presurgery rectal swab, home collected stool, and sigmoid biopsy samples were obtained from 231 subjects undergoing screening or surveillance colonoscopy. 16S rRNA analysis was performed on 552 samples (231 rectal swab, 183 stool, 138 biopsy) and operational taxonomic units (OTU) were identified using UPARSE. Non-parametric statistical methods were used to identify OTUs that were significantly different between subjects with and without polyps. These informative OTUs were then used to build classifiers to predict the presence of polyps using advanced machine learning models. RESULTS: We obtained clinical data on 218 subjects (87 females, 131 males) of which 193 were White, 21 African-American, and 4 Asian-American. Colonoscopy detected polyps in 56% of subjects. Modelling of the non-invasive home stool samples resulted in a classification accuracy >75% for Naïve Bayes and Neural Network models using informative OTUs. A naïve holdout analysis performed on home stool samples resulted in an average false negative rate of 11.5% for the Naïve Bayes and Neural Network models, which was reduced to 5% when the two models were combined. CONCLUSION: Gut microbiome analysis combined with advanced machine learning represents a promising approach to screen patients for the presence of polyps, with the potential to optimise the use of colonoscopy, reduce morbidity and mortality associated with CRC, and reduce associated healthcare costs.

Neonatal Mortality and Morbidity in Regional Provincial Hospitals in the People's Democratic Republic of Laos.

OBJECTIVE: The aim of this study was to identify the causes and incidences of neonatal diseases and deaths in five provincial hospitals in People's Democratic Republic of Laos retrospectively for the years 2010-12. METHODS: Data of neonatal patients were collected before a 3-year-training program for medical and nursing staff involved in the care of newborn infants in the provincial and associated district hospitals. RESULTS: In the years 2010-12, a total of 1673 neonatal patients were treated in the provincial hospitals. The reasons of treatment were as follows: 48% infections, 17% complications of prematurity, 14% intrapartum-related complications and 9% other, not categorized diseases. The average mortality rate in all hospitals was 6.5%. The main causes of death were complications because of prematurity, infectious diseases and asphyxia. CONCLUSION: These data could be the basis for any teaching program aimed at reducing neonatal mortality. Furthermore, they enable an evaluation of the ongoing teaching program.

Respirator Testing Using Virus Aerosol: Comparison between Viability Penetration and Physical Penetration.

Viability, fluorescence (particle volume), photometric, viral RNA, and particle number penetration of MS2 bacteriophage through filter media used in three different models of respirators were compared to better understand the correlation between viability and physical penetration. Although viability and viral RNA penetration were better represented by particle volume penetration than particle number penetration, they were several-fold lower than photometric penetration, which was partially due to the difference in virus survival between upstream and downstream aerosol samples. Results suggest that the current NIOSH photometer-based test method can be used as a quick means to roughly differentiate respirators with different performance against virus aerosols.

Survival of airborne MS2 bacteriophage generated from human saliva, artificial saliva, and cell culture medium.

Laboratory studies of virus aerosols have been criticized for generating airborne viruses from artificial nebulizer suspensions (e.g., cell culture media), which do not mimic the natural release of viruses (e.g., from human saliva). The objectives of this study were to determine the effect of human saliva on the infectivity and survival of airborne virus and to compare it with those of artificial saliva and cell culture medium. A stock of MS2 bacteriophage was diluted in one of three nebulizer suspensions, aerosolized, size selected (100 to 450 nm) using a differential mobility analyzer, and collected onto gelatin filters. Uranine was used as a particle tracer. The resulting particle size distribution was measured using a scanning mobility particle sizer. The amounts of infectious virus, total virus, and fluorescence in the collected samples were determined by infectivity assays, quantitative reverse transcription-PCR (RT-PCR), and spectrofluorometry, respectively. For all nebulizer suspensions, the virus content generally followed a particle volume distribution rather than a number distribution. The survival of airborne MS2 was independent of particle size but was strongly affected by the type of nebulizer suspension. Human saliva was found to be much less protective than cell culture medium (i.e., 3% tryptic soy broth) and artificial saliva. These results indicate the need for caution when extrapolating laboratory results, which often use artificial nebulizer suspensions. To better assess the risk of airborne transmission of viral diseases in real-life situations, the use of natural suspensions such as saliva or respiratory mucus is recommended.

Comparison of spike and aerosol challenge tests for the recovery of viable influenza virus from non-woven fabrics.

BACKGROUND: To experimentally determine the survival kinetics of influenza virus on personal protective equipment (PPE) and to evaluate the risk of virus transfer from PPE, it is important to compare the effects on virus recovery of the method used to contaminate the PPE with virus and the type of eluent used to recover it. METHODS: Avian influenza virus (AIV) was applied as a liquid suspension (spike test) and as an aerosol to three types of non-woven fabrics [polypropylene (PP), polyester (PET), and polyamide (Nylon)] that are commonly used in the manufacture of PPE. This was followed by virus recovery using eight different eluents (phosphate-buffered saline, minimum essential medium, and 1.5% or 3.0% beef extract at pH 7, 8, or 9). RESULTS: For spike tests, no statistically significant difference was found in virus recovery using any of the eluents tested. Hydrophobic surfaces (PP and PET) yielded higher spiked virus recovery than hydrophilic Nylon. From all materials, the virus recovery was much lower in aerosol challenge tests than in spike tests. CONCLUSIONS: Significant differences were found in the recovery of viable AIV from non-woven fabrics between spike and aerosol challenge tests. The findings of this study demonstrate the need for realistic aerosol challenge tests rather than liquid spike tests in studies of virus survival on surfaces where airborne transmission of influenza virus may get involved.

Performance evaluation of filtering facepiece respirators using virus aerosols.

Physical penetration and infectivity penetration of adenovirus and influenza virus aerosols through respirators were measured to better characterize the effectiveness of filtering facepiece respirators against airborne virus. A physical penetration of 2%-5% was found. However, large sample-to-sample variation made it difficult to quantify the difference in physical penetration caused by the different virus aerosols. Infectivity penetration of adenovirus was much lower than physical penetration, indicating that the latter provides a conservative estimate for respirator performance.

Detection of viruses in used ventilation filters from two large public buildings.

BACKGROUND: Viral and bacterial pathogens may be present in the air after being released from infected individuals and animals. Filters are installed in the heating, ventilation, and air-conditioning (HVAC) systems of buildings to protect ventilation equipment and maintain healthy indoor air quality. These filters process enormous volumes of air. This study was undertaken to determine the utility of sampling used ventilation filters to assess the types and concentrations of virus aerosols present in buildings. METHODS: The HVAC filters from 2 large public buildings in Minneapolis and Seattle were sampled to determine the presence of human respiratory viruses and viruses with bioterrorism potential. Four air-handling units were selected from each building, and a total of 64 prefilters and final filters were tested for the presence of influenza A, influenza B, respiratory syncytial, corona, parainfluenza 1-3, adeno, orthopox, entero, Ebola, Marburg, Lassa fever, Machupo, eastern equine encephalitis, western equine encephalitis, and Venezuelan equine encephalitis viruses. Representative pieces of each filter were cut and eluted with a buffer solution. RESULTS: Attempts were made to detect viruses by inoculation of these eluates in cell cultures (Vero, MDCK, and RK-13) and specific pathogen-free embryonated chicken eggs. Two passages of eluates in cell cultures or these eggs did not reveal the presence of any live virus. The eluates were also examined by polymerase chain reaction or reverse-transcription polymerase chain reaction to detect the presence of viral DNA or RNA, respectively. Nine of the 64 filters tested were positive for influenza A virus, 2 filters were positive for influenza B virus, and 1 filter was positive for parainfluenza virus 1. CONCLUSION: These findings indicate that existing building HVAC filters may be used as a method of detection for airborne viruses. As integrated long-term bioaerosol sampling devices, they may yield valuable information on the epidemiology and aerobiology of viruses in air that can inform the development of methods to prevent airborne transmission of viruses and possible deterrents against the spread of bioterrorism agents.

Congenital ichthyosis in severe type II Gaucher disease with a homozygous null mutation.

This paper describes a neonate with type II Gaucher disease. The phenotype was unusually severe with congenital ichthyosis, hepatosplenomegaly, muscular hypotonia, myoclonus and respiratory failure. Electron microscopy of the skin revealed lamellar body contents in the stratum corneum interstices, appearances considered to be typical of type II Gaucher disease. The baby died from respiratory failure 1 month postpartum having made no neurological progress. Molecular analysis identified a previously not reported homozygous null mutation, c.1505G→A of the ß-glucocerebrosidase gene.

Laboratory and on-road evaluations of cabin air filters using number and surface area concentration monitors.

An automotive cabin air filter's effectiveness for removing airborne particles was determined both in a laboratory wind tunnel and in vehicle on-road tests. The most penetrating particle size for the test filter was approximately 350 nm, where the filtration efficiency was 22.9 and 17.4% at medium and high fan speeds, respectively. The filtration efficiency increased for smaller particles and was 43.9% for 100 nm and 72.0% for 20 nm particles at a medium fan speed. We determined the reduction in passenger exposure to particles while driving in freeway traffic caused by a vehicle ventilation system with a cabin air filter installed. Both particle number and surface area concentration measurements were made inside the cabin and in the surrounding air. At medium fan speed, the number and surface area concentration-based exposure reductions were 65.6 +/- 6.0% and 60.6 +/- 9.4%, respectively. To distinguish the exposure reduction contribution from the filter alone and the remainder of the ventilation system, we also performed tests with and without the filter in place using the surface area monitors. The ventilation system operating in the recirculation mode with the cabin air filter installed provided the maximum protection, reducing the cabin particle concentration exponentially over time and usually taking only 3 min to reach 10 microm2/cm3 (a typical office air condition) under medium fan speed.

Background culturable bacteria aerosol in two large public buildings using HVAC filters as long term, passive, high-volume air samplers.

Background culturable bacteria aerosols were collected and identified in two large public buildings located in Minneapolis, Minnesota and Seattle, Washington over a period of 5 months and 3 months, respectively. The installed particulate air filters in the ventilation systems were used as the aerosol sampling devices at each location. Both pre and final filters were collected from four air handing units at each site to determine the influence of location within the building, time of year, geographical location and difference between indoor and outdoor air. Sections of each loaded filter were eluted with 10 ml of phosphate buffered saline (PBS). The resulting solutions were cultured on blood agar plates and incubated for 24 h at 36 degrees C. Various types of growth media were then used for subculturing, followed by categorization using a BioLog MicroStation (Biolog, Hayward, CA, USA) and manual observation. Environmental parameters were gathered near each filter by the embedded on-site environmental monitoring systems to determine the effect of temperature, humidity and air flow. Thirty nine different species of bacteria were identified, 17 found only in Minneapolis and 5 only in Seattle. The hardy spore-forming genus Bacillus was the most commonly identified and showed the highest concentrations. A significant decrease in the number of species and their concentration occurred in the Minneapolis air handling unit supplying 100% outdoor air in winter, however no significant correlations between bacteria concentration and environmental parameters were found.

Development of a method for bacteria and virus recovery from heating, ventilation, and air conditioning (HVAC) filters.

The aim of the work presented here is to study the effectiveness of building air handling units (AHUs) in serving as high volume sampling devices for airborne bacteria and viruses. An HVAC test facility constructed according to ASHRAE Standard 52.2-1999 was used for the controlled loading of HVAC filter media with aerosolized bacteria and virus. Nonpathogenic Bacillus subtilis var. niger was chosen as a surrogate for Bacillus anthracis. Three animal viruses; transmissible gastroenteritis virus (TGEV), avian pneumovirus (APV), and fowlpox virus were chosen as surrogates for three human viruses; SARS coronavirus, respiratory syncytial virus, and smallpox virus; respectively. These bacteria and viruses were nebulized in separate tests and injected into the test duct of the test facility upstream of a MERV 14 filter. SKC Biosamplers upstream and downstream of the test filter served as reference samplers. The collection efficiency of the filter media was calculated to be 96.5 +/- 1.5% for B. subtilis, however no collection efficiency was measured for the viruses as no live virus was ever recovered from the downstream samplers. Filter samples were cut from the test filter and eluted by hand-shaking. An extraction efficiency of 105 +/- 19% was calculated for B. subtilis. The viruses were extracted at much lower efficiencies (0.7-20%). Our results indicate that the airborne concentration of spore-forming bacteria in building AHUs may be determined by analyzing the material collected on HVAC filter media, however culture-based analytical techniques are impractical for virus recovery. Molecular-based identification techniques such as PCR could be used.