Source strengths obtained with three clean air suits fulfilling the requirements for high performance in EN 13795-2:2019: An experimental study

Introduction: Clothing made from tight material worn by operating room staff adds to the effect achieved by ventilation in the effort to keep a low level of bacteria in the operating room air. The material used for clean air suits should be tested according to the standard EN 13795-2. Aim: The aim of the study was to investigate whether there was a difference in protective capacity between three clean air suits made from materials fulfilling the requirements of EN 13795-2:2019 and designed as described in Annex E of the standard. Materials and methods: Eight people (five men and three women) performed standardized movements in a dispersal chamber with a fixed supply air flow. Each person performed two test cycles with each clean air suit. Counts of colony-forming units (CFU) in the air were measured during testing and source strength was calculated for each test cycle. Results: The mean values of source strength for the three clean air suits were 1.4 CFU/s, 0.8 CFU/s and 0.7 CFU/s. The difference between the most and the least protective garment was statistically significant (p < 0.05). Conclusions: Clean air suits made from material fulfilling the requirements for ‘high performance’ in the standard EN 13795-2:2019 might show a significant difference in protective capacity when comparing source strength. Tests for measuring of source strength in a dispersal chamber can be performed as suggested in Annex E of the standard, i.e. ‘The test person is male, 20–50 years old, with no visible skin disorder’

Pronounced Fixation, Strong Population Differentiation and Complex Population History in the Canary Islands Blue Tit Subspecies Complex

Evolutionary molecular studies of island radiations may lead to insights in the role of vicariance, founder events, population size and drift in the processes of population differentiation. We evaluate the degree of population genetic differentiation and fixation of the Canary Islands blue tit subspecies complex using microsatellite markers and aim to get insights in the population history using coalescence based methods. The Canary Island populations were strongly genetically differentiated and had reduced diversity with pronounced fixation including many private alleles. In population structure models, the relationship between the central island populations (La Gomera, Tenerife and Gran Canaria) and El Hierro was difficult to disentangle whereas the two European populations showed consistent clustering, the two eastern islands (Fuerteventura and Lanzarote) and Morocco weak clustering, and La Palma a consistent unique lineage. Coalescence based models suggested that the European mainland forms an outgroup to the Afrocanarian population, a split between the western island group (La Palma and El Hierro) and the central island group, and recent splits between the three central islands, and between the two eastern islands and Morocco, respectively. It is clear that strong genetic drift and low level of concurrent gene flow among populations have shaped complex allelic patterns of fixation and skewed frequencies over the archipelago. However, understanding the population history remains challenging; in particular, the pattern of extreme divergence with low genetic diversity and yet unique genetic material in the Canary Island system requires an explanation. A potential scenario is population contractions of a historically large and genetically variable Afrocanarian population, with vicariance and drift following in the wake. The suggestion from sequence-based analyses of a Pleistocene extinction of a substantial part of North Africa and a Pleistocene/Holocene eastward re-colonisation of western North Africa from the Canaries remains possible

Skeletal Muscle Myofibrillar and Sarcoplasmic Protein Synthesis Rates Are Affected Differently by Altitude-Induced Hypoxia in Native Lowlanders

As a consequence to hypobaric hypoxic exposure skeletal muscle atrophy is often reported. The underlying mechanism has been suggested to involve a decrease in protein synthesis in order to conserve O2. With the aim to challenge this hypothesis, we applied a primed, constant infusion of 1-13C-leucine in nine healthy male subjects at sea level and subsequently at high-altitude (4559 m) after 7–9 days of acclimatization. Physical activity levels and food and energy intake were controlled prior to the two experimental conditions with the aim to standardize these confounding factors. Blood samples and expired breath samples were collected hourly during the 4 hour trial and vastus lateralis muscle biopsies obtained at 1 and 4 hours after tracer priming in the overnight fasted state. Myofibrillar protein synthesis rate was doubled; 0.041±0.018 at sea-level to 0.080±0.018%⋅hr−1 (p<0.05) when acclimatized to high altitude. The sarcoplasmic protein synthesis rate was in contrast unaffected by altitude exposure; 0.052±0.019 at sea-level to 0.059±0.010%⋅hr−1 (p>0.05). Trends to increments in whole body protein kinetics were seen: Degradation rate elevated from 2.51±0.21 at sea level to 2.73±0.13 µmol⋅kg−1⋅min−1 (p = 0.05) at high altitude and synthesis rate similar; 2.24±0.20 at sea level and 2.43±0.13 µmol⋅kg−1⋅min−1 (p>0.05) at altitude. We conclude that whole body amino acid flux is increased due to an elevated protein turnover rate. Resting skeletal muscle myocontractile protein synthesis rate was concomitantly elevated by high-altitude induced hypoxia, whereas the sarcoplasmic protein synthesis rate was unaffected by hypoxia. These changed responses may lead to divergent adaptation over the course of prolonged exposure

Safety Ventilation in Operating Rooms - A Review

Safety ventilation is defined as the interaction between air movements and the dispersion of contaminants in industrial environments and the control of these environments, both regarding human safety and product safety/cleanliness. The hospital environment is contaminated by microorganisms; some of them are antibiotic resistant. The number of airborne bacteriacarrying particles in the operating room is considered as an indicator of the risk of infections to the patient undergoing surgery susceptible to infections. To prevent surgical site infection, it is desirable to keep the bacteria-carrying particles at a low number in the operating room air, especially during ortopaedic surgery. The review deals with practical safety ventilation in operating rooms with regard to airborne bacteria-carrying particles and describes the technical control measures: ventilation(air distribution) and clothing systems