Quantifying the reduction of airborne infectious viral load using a ventilated patient hood.

BACKGROUND: Healthcare workers treating SARS-CoV-2 patients are at risk of infection by respiratory exposure to patient-emitted, virus-laden aerosols. Source control devices such as ventilated patient isolation hoods have been shown to limit the dissemination of non-infectious airborne particles in laboratory tests, but data on their performance in mitigating the airborne transmission risk of infectious viruses are lacking. AIM: We used an infectious airborne virus to quantify the ability of a ventilated hood to reduce infectious virus exposure in indoor environments. METHODS: We nebulized 109 plaque forming units (pfu) of bacteriophage PhiX174 virus into a ∼30-m3 room when the hood was active or inactive. The airborne concentration of infectious virus was measured by BioSpot-VIVAS and settle plates using plaque assay quantification on the bacterial host Escherichia coli C. The airborne particle number concentration (PNC) was also monitored continuously using an optical particle sizer. FINDINGS: The median airborne viral concentration in the room reached 1.41 × 105 pfu/m3 with the hood inactive. When active, the hood reduced infectious virus concentration in air samples by 374-fold. The deposition of infectious virus on the surface of settle plates was reduced by 87-fold. This was associated with a 109-fold reduction in total airborne particle number escape rate. CONCLUSION: A personal ventilation hood significantly reduced airborne particle escape, considerably lowering infectious virus contamination in an indoor environment. Our findings support the further development of source control devices to mitigate nosocomial infection risk among healthcare workers exposed to airborne viruses in clinical settings.

Effectiveness of portable air filtration on reducing indoor aerosol transmission: preclinical observational trials.

BACKGROUND: While the range of possible transmission pathways of severe acute respiratory syndrome coronavirus-2 in various settings has been investigated thoroughly, most authorities have recently acknowledged the role of aerosol spread in its transmission, especially in indoor environments where ventilation is poor. Engineering controls are needed to mitigate aerosol transmission in high-risk settings including hospital wards, classrooms and offices. AIM: To assess the effectiveness of aerosol filtration by portable air cleaning devices with high-efficiency particulate air filters used in addition to a standard building heating ventilation and air conditioning (HVAC) system. METHODS: Test rooms, including a single-bed hospital room, were filled with test aerosol to simulate aerosol movement. Aerosol counts were measured over time with various portable air cleaning devices and room ventilation systems to quantify the overall aerosol clearance rate. FINDINGS: Portable air cleaning devices were very effective for removal of aerosols. The aerosols were cleared five times faster in a small control room with portable air cleaning devices than in the room with HVAC alone. The single-bed hospital room had an excellent ventilation rate (∼14 air changes per hour) and cleared the aerosols in 20 min. However, with the addition of two air cleaning devices, the clearance time was three times faster. CONCLUSIONS: Inexpensive portable air cleaning devices should be considered for small and enclosed spaces in healthcare settings, such as inpatient rooms and personal protective equipment donning/doffing stations. Portable air cleaning devices are particularly important where there is limited ability to reduce aerosol transmission with building HVAC ventilation.

Reviving through human hippocampal newborn neurons.

Recent contradictory data has renewed discussion regarding the existence of adult hippocampal neurogenesis (AHN) in humans, i.e., the continued production of new neurons in the brain after birth. The present review revisits the debate of AHN in humans from a historical point of view in the face of contradictory evidence, analyzing the methods employed to investigate this phenomenon. Thus, to date, of the 57 studies performed in humans that we reviewed, 84% (48) concluded in favor of the presence of newborn neurons in the human adult hippocampus. Besides quality of the tissue (such as postmortem intervals below 26hours as well as tissue conservation and fixation), considerations for assessing and quantify AHN in the human brain require the use of stereology and toxicological analyses of clinical data of the patient.

The homogenous alternative to biomineralization: Zn- and Mn-rich materials enable sharp organismal "tools" that reduce force requirements.

We measured hardness, modulus of elasticity, and, for the first time, loss tangent, energy of fracture, abrasion resistance, and impact resistance of zinc- and manganese-enriched materials from fangs, stings and other "tools" of an ant, spider, scorpion and nereid worm. The mechanical properties of the Zn- and Mn-materials tended to cluster together between plain and biomineralized "tool" materials, with the hardness reaching, and most abrasion resistance values exceeding, those of calcified salmon teeth and crab claws. Atom probe tomography indicated that Zn was distributed homogeneously on a nanometer scale and likely bound as individual atoms to more than » of the protein residues in ant mandibular teeth. This homogeneity appears to enable sharper, more precisely sculpted "tools" than materials with biomineral inclusions do, and also eliminates interfaces with the inclusions that could be susceptible to fracture. Based on contact mechanics and simplified models, we hypothesize that, relative to plain materials, the higher elastic modulus, hardness and abrasion resistance minimize temporary or permanent tool blunting, resulting in a roughly 2/3 reduction in the force, energy, and muscle mass required to initiate puncture of stiff materials, and even greater force reductions when the cumulative effects of abrasion are considered. We suggest that the sharpness-related force reductions lead to significant energy savings, and can also enable organisms, especially smaller ones, to puncture, cut, and grasp objects that would not be accessible with plain or biomineralized "tools".

Approaching the motional ground state of a 10-kg object.

The motion of a mechanical object, even a human-sized object, should be governed by the rules of quantum mechanics. Coaxing them into a quantum state is, however, difficult because the thermal environment masks any quantum signature of the object's motion. The thermal environment also masks the effects of proposed modifications of quantum mechanics at large mass scales. We prepared the center-of-mass motion of a 10-kilogram mechanical oscillator in a state with an average phonon occupation of 10.8. The reduction in temperature, from room temperature to 77 nanokelvin, is commensurate with an 11 orders-of-magnitude suppression of quantum back-action by feedback and a 13 orders-of-magnitude increase in the mass of an object prepared close to its motional ground state. Our approach will enable the possibility of probing gravity on massive quantum systems.

Image reconstruction: Part 1 - understanding filtered back projection, noise and image acquisition.

Image reconstruction is an increasingly complex field in CT. Iterative Reconstruction (IR) is at present an adjunct to standard Filtered Back Projection (FBP) reconstruction, but could become a replacement for it. Due to its potential for scanning at lower radiation doses, IR has received a lot of attention in the medical literature and all vendors offer commercial solutions. Its use in cardiovascular CT has been driven in part due to concerns about radiation dose and image quality. This paper is the first manuscript of a pair. It aims to review the basic principles of CT scanning, to describe image reconstruction using Filtered Back Projection, and to identify the physical processes that contribute to image noise which IR may be able to compensate for. The aim is to enable cardiovascular imagers to understand what happens to the raw data prior to the reconstruction process so they may have a better appreciation of the strengths and weaknesses of the various reconstruction techniques available. The second manuscript of this pair will discuss the various vendor permutations of IR in more detail, including the most recent machine learning based offerings, and critically appraise the current clinical research available on the various IR techniques used in cardiovascular CT.

Image reconstruction in cardiovascular CT: Part 2 - Iterative reconstruction; potential and pitfalls.

The use of IR in CT previously has been prohibitively complicated and time consuming, however improvements in computer processing power now make it possible on almost all CT scanners. Due to its potential to allow scanning at lower doses, IR has received a lot of attention in the medical literature and has become a successful commercial product. Its use in cardiovascular CT has been driven in part due to concerns about radiation dose and image quality. This manuscript discusses the various vendor permutations of iterative reconstruction (IR) in detail and critically appraises the current clinical research available on the various IR techniques used in cardiovascular CT.

Texture analysis of cardiovascular magnetic resonance cine images differentiates aetiologies of left ventricular hypertrophy.

AIM: To investigate whether unenhanced cardiovascular magnetic resonance (CMR) balanced steady state free precession (bSSFP) cine images could be analysed using textural analysis (TA) software to differentiate different aetiologies of disease causing increased myocardial wall thickness (left ventricular hypertrophy [LVH]) and indicate the severity of myocardial tissue abnormality. MATERIALS AND METHODS: A mid short axis unenhanced cine frame of 216 patients comprising 50 cases of hypertrophic cardiomyopathy (HCM; predominantly Left ventricular outflow tract obstruction [LVOTO] subtype), 52 cases of cardiac amyloid (CA; predominantly AL: light chain subtype), 68 cases of aortic stenosis (AS), 15 hypertensive patients with LVH (HTN+LVH), and 31 healthy volunteers (HV) underwent TA of the CMR cine images (CMRTA) using TexRAD (TexRAD Ltd, Cambridge, UK). Among the HV, 16/31 were scanned twice to form a test-retest reproducibility cohort. CMRTA comprised a filtration-histogram technique to extract and quantify features using six parameters. RESULTS: Test-retest analysis in the HV showed a medium filter (3 mm) was the most reproducible (intra-class correlation of 0.9 for kurtosis and skewness and 0.8 for mean and SD). Disease cohorts were statistically different (p<0.001) to HV for all parameters. Pairwise comparisons of CMRTA parameters showed kurtosis and skewness was consistently significant in ranking the degree of difference from HV (greatest to least): CA, HCM, LVH+HTN, AS (p<0.001). Similarly, mean, standard deviation, entropy, and mean positive pixel (MPP) were consistent in ranking degree of difference from HV: HCM, CA, AS and HTN+LVH. CONCLUSION: Radiomic features of bSSFP CMR data sets derived using TA show promise in discriminating between the aetiologies of LVH.

A Simple and Sensitive Method for Quantitative Measurement of Methylmalonic Acid by Turbulent Flow Chromatography and Tandem Mass Spectrometry.

A simple and sensitive method for the detection of methylmalonic acid in serum without derivatization has been developed. This method implements protein precipitation using methanol followed by additional sample clean up by turbulent flow liquid chromatography (TFLC). The sample was directly injected into the turbulent flow liquid chromatography tandem mass spectrometry system (TFLC-MS/MS) for online extraction followed by HPLC separation. The eluent was transferred to the mass spectrometer and ionized by heated electrospray negative ionization (HESI) and the analyte was quantified using a six-point calibration curve. The validated analytical measurement range (AMR) is 30-1,000 nMol/L. Dilutions of 10 and 200-fold were validated giving a clinical reportable range (CRR) of 30-200,000 nMol/L. The between-day and within-day imprecision values at concentrations spanning the AMR were less than 15%. This method was compared to an established LC-MS/MS method at a CLIA certified national reference laboratory and shows an excellent correlation with our TFLC-MS/MS method.

Squeezed quadrature fluctuations in a gravitational wave detector using squeezed light.

Squeezed states of light are an important tool for optical measurements below the shot noise limit and for optical realizations of quantum information systems. Recently, squeezed vacuum states were deployed to enhance the shot noise limited performance of gravitational wave detectors. In most practical implementations of squeezing enhancement, relative fluctuations between the squeezed quadrature angle and the measured quadrature (sometimes called squeezing angle jitter or phase noise) are one limit to the noise reduction that can be achieved. We present calculations of several effects that lead to quadrature fluctuations, and use these estimates to account for the observed quadrature fluctuations in a LIGO gravitational wave detector. We discuss the implications of this work for quantum enhanced advanced detectors and even more sensitive third generation detectors.

Reducing co-administration of clopidogrel and proton pump inhibitors in acute coronary syndromes.

BACKGROUND: Recent concerns about clopidogrel and proton pump inhibitor (PPI) co-administration in patients following an acute coronary syndrome (ACS) led us to investigate our practice. Guidance recommends that omeprazole and esomeprazole should not be co-administered with clopidogrel as they can decrease its efficacy. Pantoprazole and lansoprazole are safer for use in these cases. METHODS: Patients discharged between August 2008 and July 2009 with a diagnosis of ACS, on both clopidogrel and any PPI, were identified using the pharmacy database. Their notes were retrospectively reviewed, the indication for a PPI was checked and whether an appropriate one had been prescribed was assessed. As a result of our findings a simple algorithm was introduced to set out guidance on appropriate use and junior doctors were informed of the new procedure. We then performed another audit of patients discharged between August 2009 and February 2010 to ensure that the guidelines were being followed. RESULTS: During the first phase of the audit 43 out of 91 patients (47.5%) received a PPI with clopidogrel. Following our intervention, re-auditing confirmed that clopidogrel and PPI co-administration had decreased significantly to 27 out of 101 patients (26.7%) (p = 0.018). CONCLUSIONS: Through a simple intervention with an algorithm and education of junior doctors we have shown that significant improvement and adherence to guidance can be achieved.

Development of a cardiologist delivered service leads to improved outcomes following admission with acute coronary syndromes in a large district general hospital.

BACKGROUND: East Lancashire Hospitals NHS Trust reorganized its services in October 2007 with acute admissions sent to one site which allowed the development of a 24/7 Consultant delivered cardiology service. METHODS: A retrospective analysis of all patients admitted with an acute coronary syndrome between two periods: Group 1: October 2006 to September 2007 and Group 2: October 2007 and September 2008. We looked at the following end points-length of stay, in-hospital and 30 day all cause mortality. RESULTS: 633 patients in group 1 and 748 patients in group 2. There was significant reduction in length of stay from a median (IQ range) 7 (5-11) days to 5 (3-9) days; P<0.0001. The in-hospital mortality reduced from 15.8% (n=100) to 7.6% (n=56); P<0.0001. The mortality at 30 days reduced from 15.2% (n=96) to 8.3% (n=62); P<0.0001. These reductions remained significant after adjustment for demographic and risk factor variables. CONCLUSION: A 24/7 Consultant Cardiologist delivered cardiac care is associated with marked reductions in all cause mortality following admission with acute coronary syndromes. This improvement occurred with a significant reduction in hospital length of stay.

Changes in arterial stiffness but not carotid intimal thickness in acromegaly.

CONTEXT: Acromegaly increases cardiovascular morbidity. We tested the hypothesis that increased arterial stiffness together with left ventricular hypertrophy may be a contributory factor. PATIENTS AND DESIGN: Fifty-six patients (40 males, 54 ± 13 yr; 25 active disease, 31 in remission) and 46 healthy controls (30 males, 52 ± 13 yr) underwent measurements of aortic pulse wave velocity (PWV), carotid Doppler (IMT), echocardiography, and cardiovascular risk factors. RESULTS: Mean serum IGF-I was 323 ± 286 ng/ml (sd score 1.8 ± 1.9) in all patients. Age, body mass index, diastolic blood pressure (BP), and lipid levels were similar comparing patients and controls. Systolic BP (130.8 ± 19.9 vs. 122 ± 14 mm Hg controls, P < 0.01) and PWV (11.7 ± 3.8 vs. 9.7 ± 2.8 m/sec, 95% confidence interval -3.4 to -0.7, P <0.01) were higher in patients than controls. Regression analysis revealed age, presence of acromegaly, systolic BP, and body mass index, inversely, as significantly and independently associated with PWV. No difference in carotid IMT was seen (0.8 ± 0.2 patients vs. 0.7 ± 0.2 mm controls, P = 0.5) or between active/controlled disease. In the subset of participants with echocardiography (n = 32), left ventricular mass was higher by a mean of 38.2 g (95% confidence interval -80.9 to +4.6, P = 0.08). CONCLUSION: In summary, patients with acromegaly had independently and significantly increased aortic PWV as evidence of arterial stiffening but unaltered carotid IMT compared with controls, also influenced by age and systolic BP. Premature cardiovascular disease in patients with acromegaly is likely related to pressure-related arterial and left ventricular stiffening rather than atherosclerotic disease.

Over-expression of STP13, a hexose transporter, improves plant growth and nitrogen use in Arabidopsis thaliana seedlings.

In Arabidopsis thaliana, the regulation of hexose levels by the large monosaccharide transporter (MST) gene family influences many aspects of plant growth. The cloning and transgenic expression of one family member (STP13) enabled the manipulation of carbon (C) and nitrogen (N) metabolism in Arabidopsis. Transgenic seedlings constitutively over-expressing STP13 (STP13OX) had increased rates of glucose uptake, higher endogenous sucrose levels and accumulated more total C and biomass per plant when grown on soil-less media supplemented with 55 mM glucose and sufficient N (9 mM nitrate). Furthermore, STP13OX seedlings acquired 90% more total N than the Col-0 seedlings, and had higher levels of expression of the nitrate transporter NRT2.2. In addition, STP13OX seedlings were larger and had higher biomass than Col-0 seedlings when grown under a limiting N condition (3 mM nitrate). Transgene analysis of STP13 reveals that its gene product is localized to the plasma membrane (PM) in tobacco BY-2 suspension cells, that it encodes a functional MST in planta, and that the STP13 promoter directs GUS expression to the vasculature and to leaf mesophyll cells. This work highlights the link between C and N metabolism, demonstrating that a plant's N use may be improved by increasing the availability of C.

Perceptions of health and health service utilization among homeless and housed psychiatric consumer/survivors.

Homelessness has a direct impact on health. Homeless individuals report several barriers to accessing health care. Although research exists regarding the utilization of health services for homeless and housed psychiatric consumer/survivors, few studies have compared the perceived health and service utilization of these two groups. The objective of this study was to determine whether or not differences exist between the utilization of health services and the perceptions of health of homeless and housed psychiatric consumer/survivors in London, Ontario, Canada. It was hypothesized that differences would exist between homeless and housed psychiatric consumer/survivors on all health-related variables examined. A secondary analysis of quantitative data was conducted in a Community-University Research Alliance on Mental Health and Housing project funded by the Social Sciences and Humanities Research Council of Canada. Key findings include significant differences in the characteristics of each population, the use of health services and their perceptions of health. Implications for practice and policy are discussed.

On the use of retrograde tracers for identification of axon collaterals with multiple fluorescent retrograde tracers.

A common method for identifying collateral projections is to inject different retrograde tracers into two targets and examine labeled cells for the presence of both tracers. Double-labeled cells are considered to have collateral projections to the two injection sites. This method is widely considered to underestimate the extent of collaterals. To test the efficiency of double-labeling, we mixed equal volumes of two tracers, injected them into one site in a guinea-pig brain, and counted the resulting labeled cells. Ideally, the tracers would have precisely overlapping injection sites and all labeled cells would contain both tracers. We tested several combinations of tracers: 1) Fast Blue and fluorescein dextran; 2) fluorescein dextran and FluoroGold; 3) fluorescein dextran and FluoroRuby; 4) FluoroGold and green beads; 5) FluoroGold and red beads; 6) FluoroRuby and green beads; and, 7) green beads and red beads. For each combination, a mixture was injected into the left inferior colliculus. After 1 week to allow for transport, labeled cells were counted in the right inferior colliculus and the left temporal cortex. For each mixture, the results were similar for the two areas. The percentage of cells that were double-labeled varied from 0% to 100%, depending on tracer combination. The highest efficiencies (>96%) were observed with red beads and green beads or with FluoroRuby and fluorescein dextran. The limited efficiency of other mixtures could be accounted for only in part by incomplete overlap of the two tracers at the injection site. The results indicate that the specific combination of tracers used to search for collateral projections can greatly affect the findings.

Zinc is incorporated into cuticular "tools" after ecdysis: the time course of the zinc distribution in "tools" and whole bodies of an ant and a scorpion.

An understanding of the developmental course of specialized accumulations in the cuticular "tools" of arthropods will give clues to the chemical form, function and biology of these accumulations as well as to their evolutionary history. Specimens from individuals representing a range of developmental stages were examined using MeV - Ion microscopy. We found that zinc, manganese, calcium and chlorine began to accumulate in the mandibular teeth of the ant Tapinoma sessile after pre-ecdysial tanning, and the zinc mostly after eclosion; peak measured zinc concentrations reached 16% of dry mass. Accumulations in the pedipalp teeth, tarsal claws, cheliceral teeth and sting (aculeus) of the scorpion Vaejovis spinigeris also began after pre-ecdysial tanning and more than 48 h after ecdysis of the second instars. Zinc may be deposited in the fully formed cuticle through a network of nanometer scale canals that we observed only in the metal bearing cuticle of both the ants and scorpions. In addition to the elemental analyses of cuticular "tools", quantitative distribution maps for whole ants were obtained. The zinc content of the mandibular teeth was a small fraction of, and independent of, the total body content of zinc. We did not find specialized storage sites that were depleted when zinc was incorporated into the mandibular teeth. The similarities in the time course of zinc, manganese and calcium deposition in the cuticular "tools" of the ant (a hexapod arthropod) and those of the scorpion (a chelicerate arthropod) contribute to the evidence suggesting that heavy metal-halogen fortification evolved before these groups diverged.

Psychological distress across the course of care: a case study from implantable cardioverter defibrillator to cardiac transplantation evaluation.

The psychological distress of cardiac patients can complicate treatment or the recovery process. This case study presents a 47-year-old male recipient of an implantable cardioverter defibrillator who experienced multiple, consecutive shocks and subsequently developed anxiety and depressive difficulties. Psychological treatment to diminish these symptoms was employed. Despite declining cardiac function, the patient made significant progress in managing this negative affect. Subsequently, he was evaluated for cardiac transplant, and this treatment progress became critical evidence of his psychosocial suitability for transplant.

Cardiac transplantation in a patient with hereditary hemochromatosis: role of adjunctive phlebotomy and erythropoietin.

We describe the case of a 36-year-old woman with hereditary hemochromatosis (HH) resulting in end-stage cardiomyopathy and treated successfully with orthotopic cardiac transplantation. Before and after transplantation, the patient underwent aggressive treatment with frequent phlebotomy. We used erythropoietin concomitantly to maintain adequate hematocrit to support continued phlebotomy. We believe that aggressive use of phlebotomy provided the patient hemodynamic benefit and hastened the return of endocrine function post-transplantation. We also believe that the patient's history of high-dose vitamin C usage may have accelerated iron deposition in the heart and other vital organs.