Comparative evaluation of the hygienic efficacy of an ultra-rapid hand dryer vs conventional warm air hand dryers

Aims: To compare an ultra‐rapid hand dryer against warm air dryers, with regard to: (A) bacterial transfer after drying and (B) the impact on bacterial numbers of rubbing hands during dryer use. Methods and Results: The Airblade? dryer (Dyson Ltd) uses two air ‘knives’ to strip water from still hands, whereas conventional dryers use warm air to evaporate moisture whilst hands are rubbed together. These approaches were compared using 14 volunteers; the Airblade? and two types of warm air dryer. In study (A), hands were contaminated by handling meat and then washed in a standardized manner. After dryer use, fingers were pressed onto foil and transfer of residual bacteria enumerated. Transfers of 0–10⁷ CFU per five fingers were observed. For a drying time of 10 s, the Airblade? led to significantly less bacterial transfer than the other dryers (P < 0·05; range 0·0003–0·0015). When the latter were used for 30–35 s, the trend was for the Airblade to still perform better, but differences were not significant (P > 0·05, range 0·1317–0·4099). In study (B), drying was performed ± hand rubbing. Contact plates enumerated bacteria transferred from palms, fingers and fingertips before and after drying. When keeping hands still, there was no statistical difference between dryers, and reduction in the numbers released was almost as high as with paper towels. Rubbing when using the warm air dryers inhibited an overall reduction in bacterial numbers on the skin (P < 0·05). Conclusions: Effective hand drying is important for reducing transfer of commensals or remaining contaminants to surfaces. Rubbing hands during warm air drying can counteract the reduction in bacterial numbers accrued during handwashing. Significance and Impact of the Study: The Airblade? was superior to the warm air dryers for reducing bacterial transfer. Its short, 10 s drying time should encourage greater compliance with hand drying and thus help reduce the spread of infectious agents via hands.     

Safety evaluation of sous vide-processed products with respect to nonproteolytic Clostridium botulinum by use of challenge studies and predictive microbiological models

Sixteen different types of sous vide-processed products were evaluated for safety with respect to nonproteolytic group II Clostridium botulinum by using challenge tests with low (2. 0-log-CFU/kg) and high (5.3-log-CFU/kg) inocula and two currently available predictive microbiological models, Food MicroModel (FMM) and Pathogen Modeling Program (PMP). After thermal processing, the products were stored at 4 and 8 degrees C and examined for the presence of botulinal spores and neurotoxin on the sell-by date and 7 days after the sell-by date. Most of the thermal processes were found to be inadequate for eliminating spores, even in low-inoculum samples. Only 2 of the 16 products were found to be negative for botulinal spores and neurotoxin at both sampling times. Two products at the high inoculum level showed toxigenesis during storage at 8 degrees C, one of them at the sell-by date. The predictions generated by both the FMM thermal death model and the FMM and PMP growth models were found to be inconsistent with the observed results in a majority of the challenges. The inaccurate predictions were caused by the limited number and range of the controlling factors in the models. Based on this study, it was concluded that the safety of sous vide products needs to be carefully evaluated product by product. Time-temperature combinations used in thermal treatments should be reevaluated to increase the efficiency of processing, and the use of additional antibotulinal hurdles, such as biopreservatives, should be assessed.     

A technique to measure the ability of the human nose to warm and humidify air.

To assess the ability of the nose to warm and humidify inhaled air, we developed a nasopharyngeal probe and measured the temperature and humidity of air exiting the nasal cavity. We delivered cold, dry air (19-1 degrees C, <10% relative humidity) or hot, humid air (37 degrees C, >90% relative humidity) to the nose via a nasal mask at flow rates of 5, 10, and 20 l/min. We used a water gradient across the nose (water content in nasopharynx minus water content of delivered air) to assess nasal function. We studied the characteristics of nasal air conditioning in 22 asymptomatic, seasonally allergic subjects (out of their allergy season) and 11 nonallergic normal subjects. Inhalation of hot, humid air at increasingly higher flow rates had little effect on both the relative humidity and the temperature of air in the nasopharynx. In both groups, increasing the flow of cold, dry air lowered both the temperature and the water content of the inspired air measured in the nasopharynx, although the relative humidity remained at 100%. Water gradient values obtained during cold dry air challenges on separate days showed reproducibility in both allergic and nonallergic subjects. After exposure to cold, dry air, the water gradient was significantly lower in allergic than in nonallergic subjects (1,430 +/- 45 vs. 1,718 +/- 141 mg; P = 0.02), suggesting an impairment in their ability to warm and humidify inhaled air.     

Epidemiologic evaluation of the immunologic structure of groups with respect to hepatitis A virus

The members of a newly formed group of persons have been found to be dissimilar in the intensity of their immunity to hepatitis A virus (HAV), the character of changes in the specific antibody level and the time of its retention. In groups with the favorable situation with respect to hepatitis A, the epidemic process takes a latent course. The continuous circulation of the infective agent is ensured by the presence of the asymptomatic and inapparent forms of this infection. Changes in the specific immunostructure of groups with sporadic changes of hepatitis A are directed mainly towards an increase in the proportion of highly immune persons (with the titer of antibodies to HAV exceeding 1:2,000), the number of persons with low and medium antibody levels remaining approximately the same. Under the conditions of the northwestern region, the titer of antibodies to HAV exceeding 1:2,000 in the blood serum ensures the protection of humans from hepatitis A.     

Effect of hand heating by a warm air box on O2 consumption of the contralateral arm.

Arterialization of venous blood is often used in studying forearm metabolism. Astrup et al. [Am. J. Physiol. 255 (Endocrinol. Metab. 18): E572-E578, 1988] showed that heating of the hand by a warming blanket caused a redistribution of blood flow in the contralateral arm and thus introduced errors in forearm skeletal muscle flux calculations. The present study was undertaken to investigate how hand heating by a warm air box (60 degrees C) would affect metabolism and blood flow in the contralateral arm before and during 3 h after a glucose load. Eleven healthy volunteers (5 males, 6 females) underwent an oral glucose tolerance test (70 g) on two different occasions, one test with and one without heating of the contralateral hand, in random order. Heating the hand for 30 min before glucose intake did not affect skin temperature, rectal temperature, deep venous oxygen saturation, forearm blood flow, or oxygen consumption of forearm skeletal muscle. Although, after the glucose load, heating significantly increased forearm blood flow (P less than 0.05), the integrated response after glucose was not significantly different between control and heating experiments [67 +/- 43 and 117 +/- 41 (SE) ml/100 ml tissue]. With both conditions, there was an increase in skin temperature (P less than 0.001, integrated response control: 369 +/- 79 and heating: 416 +/- 203 degrees C) and oxygen consumption of forearm muscle (control: 290 +/- 73, P less than 0.05 and heating: 390 +/- 130 mumol/100 ml, P less than 0.05) after glucose intake. These responses did not significantly differ between the conditions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Indoor air microbiological evaluation of offices, hospitals, industries, and shopping centers

In this study it was compared the MAS-100 and the Andersen air samplers' performances and a similar trend in both instruments was observed. It was also evaluated the microbial contamination levels in 3060 samples of offices, hospitals, industries, and shopping centers, in the period of 1998 to 2002, in Rio de Janeiro city. Considering each environment, 94.3 to 99.4% of the samples were the allowed limit in Brazil (750 CFU/m3). The industries' results showed more important similarity among fungi and total heterotrophs distributions, with the majority of the results between zero and 100 CFU/m3. The offices' results showed dispersion around 300 CFU/m3. The hospitals' results presented the same trend, with an average of 200 CFU/m3. Shopping centers' environments showed an average of 300 CFU/m3 for fungi, but presented a larger dispersion pattern for the total heterotrophs, with the highest average (1000 CFU/m3). It was also investigated the correlation of the sampling period with the number of airborne microorganisms and with the environmental parameters (temperature and air humidity) through the principal components analysis. All indoor air samples distributions were very similar. The temperature and air humidity had no significant influence on the samples dispersion patterns.     

A multi-criteria decision-making model for classifying wood products with respect to their impact on environment

Background, aim and scope  

Although life cycle assessment is frequently used in scientific studies of product comparison, many practitioners are looking for improvements in the normalisation, grouping and weighting of life cycle inventory results. Local conditions, which are well known to local experts, are very important to these steps. The goal of this work was to develop a computer-based decision support system for classifying wood products according to their influence on the environment in their whole life cycle. The model specifically addresses local conditions in the Republic of Slovenia and was developed by Slovenian experts.     

Key evaluation framework for the impacts of urbanization on air environment – A case study

Pressure-State-Response (PSR) model is one of the most commonly used models for environmental impacts assessment. As an effective tool for strategic management and performance evaluation, Balanced Scorecard (BSC) has been widely applied in the management field. PSR and BSC share the similar principles such as systematic, causality and sustainability oriented. Furthermore, BSC features equilibrium and dynamics. It is a feasible and innovative approach to establish a comprehensive environmental assessment framework by combining BSC and PSR. By placing the customer indicator on the top layer and following the PSR principle on the second layer, one model was designed to examine the impact of urbanization on the air environment in Shandong Province from 2005 to 2009 with factor component analysis. The results showed that urbanization and air environmental sustainability has been an upward trend in Shandong. The sustainable development level is low in Shandong presently, which provides a large potential for further improvement. This study is a useful reference for policy makers in terms of economic and environmental management.     

Supine position decreases the ability of the nose to warm and humidify air.

We tested the hypothesis that decreasing nasal air volume (i.e., increasing nasal turbinate blood volume) improves nasal air conditioning. We performed a randomized, two-way crossover study on the conditioning capacity of the nose in six healthy subjects in the supine and upright position. Cold, dry air (CDA) was delivered to the nose via a nasal mask, and the temperature and humidity of air were measured before it entered and after it exited the nasal cavity. The total water gradient (TWG) across the nose was calculated and represents the nasal conditioning capacity. Nasal volume decreased significantly from baseline without changing the mucosal temperature when subjects were placed in the supine position (P < 0.01). TWG in supine position was significantly lower than that in upright position (P < 0.001). In the supine position, nasal mucosal temperature after CDA exposure was significantly lower than that in upright position (P < 0.01). Our data show that placing subjects in the supine position decreased the ability of the nose to condition CDA compared with the upright position, in contrast to our hypothesis.     

Using psychological theory to inform methods to optimize the implementation of a hand hygiene intervention

ABSTRACT: BACKGROUND: Careful hand hygiene (HH) is the single most important factor in preventing the transmission of infections to patients, but compliance is difficult to achieve and maintain. A lack of understanding of the processes involved in changing staff behaviour may contribute to the failure to achieve success. The purpose of this study was to identify nurses' and administrators' perceived barriers and facilitators to current HH practices and the implementation of a new electronic monitoring technology for HH. METHODS: Ten key informant interviews (three administrators and seven nurses) were conducted to explore barriers and facilitators related to HH and the impact of the new technology on outcomes. The semi structured interviews were based on the Theoretical Domains Framework by Michie et al. and conducted prior to intervention implementation. Data were explored using an inductive qualitative analysis approach. Data between administrators and nurses were compared. RESULTS: In 9 of the 12 domains, nurses and administrators differed in their responses. Administrators believed that nurses have insufficient knowledge and skills to perform HH, whereas the nurses were confident they had the required knowledge and skills. Nurses focused on immediate consequences, whereas administrators highlighted long-term outcomes of the system. Nurses concentrated foremost on their personal safety and their families' safety as a source of motivation to perform HH, whereas administrators identified professional commitment, incentives, and goal setting. Administrators stated that the staff do not have the decision processes in place to judge whether HH is necessary or not. They also highlighted the positive aspects of teams as a social influence, whereas nurses were not interested in group conformity or being compared to others. Nurses described the importance of individual feedback and self-monitoring in order to increase their performance, whereas administrators reported different views. CONCLUSIONS: This study highlights the benefits of using a structured approach based on psychological theory to inform an implementation plan for a behavior change intervention. This work is an essential step towards systematically identifying factors affecting nurses' behaviour associated with HH.     

Analysis of skin movement with respect to flexional bone motion using MR images of a hand

This study describes the methodology for analyzing skin movement with respect to the predefined flexional motion of the hand. The 3D in vivo geometric data were acquired through magnetic resonance (MR) scanning of multiple hands in various postures. Custom software was developed to segment MR images and to generate polygonal isosurfaces. A new bone coordinate system (BCS) was defined to describe the skin movement measured with the skin-surface markers. The BCS was defined by the surface registration technique, which could minimize the distance among the 3D polygonal surfaces of different postures. MR images of six subjects in the 3 postures were captured with skin-surface markers for the experiment. Skin movement on the second metacarpal bone, which was fixed during the flexional motion, ranged from 1.169 to 10.885 mm. While the distance of the skin movement varied from one subject to another, a common skin movement direction was observed among the six subjects. For the repeatability evaluation of the proposed method, the MR images of the same subject were independently processed 10 times by a trained operator. The standard deviation of the skin movement on the second metacarpal of the index finger with respect to the predefined flexional motion ranged from 0.45 to 0.74 mm.     

Wood preservation hygiene and environment in the lime-light of actually

Summary Under the ?Bois plus? scheme, the CTBA is currently developing a third party certification, based on the Scrivener law, with the aim of defending the consumers' interests. At this early stage, wood preservatives and treated wood are checked for the efficacy of treatments in order to ensure the stability and security of works in buildings and civil engineering. According to the different classes of risks in service, ?Bois plus? provides the most adeguate level of protection. In the close future, the industry is planning to incorporate, with the help of the CTBA and experts, health criteria within the frame of the ?Bois plus? certification scheme. The means could beSafety indexes, which are objectives of quality for professionals.Safety indexes are concentrations of substances in wood which can be taken as safe for humans and the general environment, while still toxic for the wood pests. This attractive experience aims to make with the brandname ?Bois plus? a synonym of efficacy and safety. This approach meets the essential requirements 1, 3, 4 of the 89/106 EEC directive: mechanical resistance and stability/hygiene, health and environment/safety in use.     

Comparison of electric hand dryers and paper towels for hand hygiene: a critical review of the literature

Numerous studies are published on the benefits of electric hand dryers vs paper towels (PT) for drying hands after washing. Data are conflicting and lacking key variables needed to assess infection risks. We provide a rapid scoping review on hand-drying methods relative to hygiene and health risks. Controlled vocabulary terms and keywords were used to search PubMed (1946–2018) and Embase (1947–2018). Multiple researchers independently screened abstracts for relevance using predetermined criteria and created a quality assessment scoring system for relative study comparisons. Of 293 papers, 23 were included in the final analysis. Five studies did not compare multiple methods; however, 2 generally favoured electric dryers (ED); 7 preferred PT; and 9 had mixed or statistically insignificant results (among these, 3 contained scenarios favourable to ED, 4 had results supporting PT, and the remaining studies had broadly conflicting results). Results were mixed among and within studies and many lacked consistent design or statistical analysis. The breadth of data does not favour one method as being more hygienic. However, some authors extended generalizable recommendations without sufficient scientific evidence. The use of tools in quantitative microbial risk assessment is suggested to evaluate health exposure potentials and risks relative to hand-drying methods. We found no data to support any human health claims associated with hand-drying methods. Inconclusive and conflicting results represent data gaps preventing the advancement of hand-drying policy or practice recommendations.     

A comparison of SCOP and CATH with respect to domain-domain interactions

The analysis and prediction of protein-protein interaction sites from structural data are restricted by the limited availability of structural complexes that represent the complete protein-protein interaction space. The domain classification schemes CATH and SCOP are normally used independently in the analysis and prediction of protein domain-domain interactions. In this article, the effect of different domain classification schemes on the number and type of domain-domain interactions observed in structural data is systematically evaluated for the SCOP and CATH hierarchies. Although there is a large overlap in domain assignments between SCOP and CATH, 23.6% of CATH interfaces had no SCOP equivalent and 37.3% of SCOP interfaces had no CATH equivalent in a nonredundant set. Therefore, combining both classifications gives an increase of between 23.6 and 37.3% in domain-domain interfaces. It is suggested that if possible, both domain classification schemes should be used together, but if only one is selected, SCOP provides better coverage than CATH. Employing both SCOP and CATH reduces the false negative rate of predictive methods, which employ homology matching to structural data to predict protein-protein interaction by an estimated 6.5%.