Comparison of virus dispersal and aerosolization by different hand-drying devices

Background World Health Organization and EU hand hygiene guidelines state that if electric hand dryers are used, they should not aerosolize pathogens. Previous studies have investigated the dispersal by different hand-drying devices of chemical indicators, fungi and bacteria on the hands. This study assessed the aerosolization and dispersal of virus on the hands to determine any differences between hand-drying devices in their potential to contaminate other occupants of public washrooms and the washroom environment. Methods A suspension of MS2, an Escherichia coli bacteriophage virus, was used to artificially contaminate the hands of participants prior to using three different hand-drying devices: jet air dryer, warm air dryer, paper towel dispenser. Virus was detected by plaque formation on agar plates layered with the host bacterium. Vertical dispersal of virus was assessed at a fixed distance (0.4 m) and over a range of different heights (0.0 – 1.8 m) from the floor. Horizontal dispersal was assessed at different distances of up to three metres from the hand-drying devices. Virus aerosolization and dispersal was also assessed at different times up to 15 minutes after use by means of air sampling at two distances (0.1 and 1.0 m) and at a distance behind and offset from each of the hand-drying devices. Results Over a range of heights, the jet air dryer was shown to produce over 60 times greater vertical dispersal of virus from the hands than a warm air dryer and over 1300 times greater than paper towels; the maximum being detected between 0.6 and 1.2 metres from the floor. Horizontal dispersal of virus by the jet air dryer was over 20 times greater than a warm air dryer and over 190 times greater than paper towels; virus being detected at distances of up to three metres. Air sampling at three different positions from the hand-drying devices 15 minutes after use showed that the jet air dryer produced over 50-times greater viral contamination of the air than a warm air dryer and over 110-times greater than paper towels. Conclusions Due to their high air speed, jet air dryers aerosolize and disperse more virus over a range of heights, greater distances, and for longer times than other hand drying devices. If hands are inadequately washed, they have a greater potential to contaminate other occupants of a public washroom and the washroom environment. Main messages: Jet air dryers with claimed air speeds of over 600 kph have a greater potential than warm air dryers or paper towels to aerosolize and disperse viruses on the hands of users. The choice of hand-drying device should be carefully considered. Jet air dryers may increase the risk of transmission of human viruses, such as norovirus, particularly if hand washing is inadequate.

Reliable and Fast Hand-Offs in Low-Power Wireless Networks

Hand-off (or hand-over), the process where mobile nodes select the best access point available to transfer data, has been well studied in wireless networks. The performance of a hand-off process depends on the specific characteristics of the wireless links. In the case of low-power wireless networks, hand-off decisions must be carefully taken by considering the unique properties of inexpensive low-power radios. This paper addresses the design, implementation and evaluation of smart-HOP, a hand-off mechanism tailored for low-power wireless networks. This work has three main contributions. First, it formulates the hard hand-off process for low-power networks (such as typical wireless sensor networks - WSNs) with a probabilistic model, to investigate the impact of the most relevant channel parameters through an analytical approach. Second, it confirms the probabilistic model through simulation and further elaborates on the impact of several hand-off parameters. Third, it fine-tunes the most relevant hand-off parameters via an extended set of experiments, in a realistic experimental scenario. The evaluation shows that smart-HOP performs well in the transitional region while achieving more than 98 percent relative delivery ratio and hand-off delays in the order of a few tens of a milliseconds.

Hand Involvement in Ollier Disease and Maffucci Syndrome: a Case Series

Ollier Disease and Maffucci Syndrome are two rare diseases that can cause tumors in several organs, having a special predilection for the hand. However, there have been very few reports in the literature focusing on hand manifestations of these diseases. We report the cases of three female patients: one with Ollier Disease, and two other with Maffucci Syndrome. All patients had hand involvement as their initial primary complaint. The Ollier Disease patient developed chondrosarcomas of two digits and had to have these fingers amputated. One of the Maffucci patients died one year after presentation from a brain glioblastoma. These cases emphasize the importance of early diagnosis of Ollier Disease and Maffucci Syndrome, as these two conditions are associated not only to crippling hand deformity, but also to a significant risk of chondrosarcoma, and other malignant tumors.

Reorganização do Controlo Postural do Tronco Ipsilesional em Indivíduos com Acidente Vascular Encefálico

Introdução: O controlo postural (CP) tem sido apontado como indicador de prognóstico funcional e constitui um dos requisitos para a execução de tarefas funcionais. Tem sido demonstrado que após um acidente vascular encefálico (AVE) este esteja severamente alterado. Os mecanismos de neuroplasticidade evidenciam capacidade de mudança no CP através de uma intervenção em Fisioterapia. Objetivos: Descrever as modificações em participantes com AVE face à intervenção em fisioterapia no: 1) componente flexor/extensor do tronco superior/inferior; 2) alinhamento das escápulas; 3) variação do Centro de Pressão (Cop) nos seus componentes medio-lateral e antero-posterior. Pretendeu-se também perceber as mudanças na de distribuição da carga entre membros através do comportamento da força vertical (Fz). Métodos: Estudo de série de casos de participantes com alterações neuromotoras decorrentes de AVE. A avaliação privilegiou a análise do potencial do participante com um objetivo de funcionalidade, tendo ocorrido em 2 momentos: M0 (inicial) e M1 (após 3 meses). Foi avaliado o alinhamento do tronco e da escápula, através do Software de Avaliação Postural (SAPO). Foi também avaliado o deslocamento antero-posterior e medio-lateral do CoP e comportamento da força vertical do solo em Plataforma de Forças. Resultados: Nos participantes A, B, C e D ocorreram modificações nas variáveis cinemáticas, observando-se uma diminuição do componente flexor do tronco e uma tendência para simetria entre as escápulas. O participante E contrariou esta tendência. Nas variáveis em Plataforma de Forças, não é possível encontrar uma tendência homogénea a todos os participantes. Conclusão: Conseguiu-se demonstrar que é possível influenciar positivamente o componente flexor/extensor do tronco superior/inferior, assim como o alinhamento das escápulas. As modificações nas variáveis enunciadas parecem indicar um melhor controlo postural do tronco.

Why did Swiss citizens refuse a comprehensive second-hand smoke ban?

The ill effects of second-hand smoke are now well documented. To protect the population from exposure to tobacco smoke, comprehensive smoking bans are necessary as expressed in the WHO Framework Convention on Tobacco Control and its guidelines. Switzerland has only a partial smoking ban full of exceptions which has been in effect since 2010, which reproduces the so-called Spanish model. In September 2012, the Swiss citizens refused a proposal for a more comprehensive ban. This case study examines the reasons behind this rejection and draws some lessons that can be learnt from it.

Cell therapies for tendons: old cell choice for modern innovation.

Although tissue engineering and cell therapies are becoming realistic approaches for medical therapeutics, it is likely that musculoskeletal applications will be among the first to benefit on a large scale. Cell sources for tissue engineering and cell therapies for tendon pathologies are reviewed with an emphasis on small defect tendon injuries as seen in the hand which could adapt well to injectable cell administration. Specifically, cell sources including tenocytes, tendon sheath fibroblasts, bone marrow or adipose-derived stem cells, amniotic cells, placenta cells and platelet-derivatives have been proposed to enhance tendon regeneration. The associated advantages and disadvantages for these different strategies will be discussed and evolving regulatory requirements for cellular therapies will also be addressed. Human progenitor tenocytes, along with their clinical cell banking potential, will be presented as an alternative cell source solution. Similar cell banking techniques have already been described with other progenitor cell types in the 1950's for vaccine production, and these "old" cell types incite potentially interesting therapeutic options that could be improved with modern innovation for tendon regeneration and repair.

« Recueil de matières de finance pour l'instruction du Roy, par M. D. C[HANDÉ]. Tome Ier. — 1722 ».

Contient : Abrégé chronologique des monnoies ; Dissertation sur la livre de compte ; Ferme du tabac ; Francs-fiefs ; Amortissemens ; Huitième et sixième denier ecclésiastique ; Insinuations laïques ; Controlle des actes des notaires ; Petits scels ; Cartes à jouer

The influence of skeletal muscle cell volume on the regulation of carbohydrate uptake and muscle metabolism

This study investigated the regulation of carbohydrate metabolism and glucose uptake through changes in skeletal muscle cell volume. Using an established invitro isolated whole muscle model, soleus (SOL) and extensor digitorum longus (EDL) muscles were dissected from male rats and incubated in an organ bath containing Sigma medium-199 with 8 mM D-glucose altered to target osmolality (hypo-osmotic: HYPO, iso-osmotic: ISO, hyper-osmotic: HYPER; 190, 290, 400 mmol/kg). Muscles were divided into two groups; metabolite (MM) and uptake (MU). MM (N=48) were incubated for 60 minutes and were then immediately flash frozen. MU (N=24) were incubated for 30 minutes and then the extracellular fluid was exchanged for media containing ^H-glucose and ^'*C-mannitol and incubated for another 30 minutes. After the incubation, the muscles were freeze clamped. Results demonstrated a relative water decrease and increase in HYPER and HYPO, respectively. EDL and SOL glucose uptakes were found to be significantly greater in HYPER conditions. The HYPER condition resulted in significant alterations in muscle metabolite concentrations (lower glycogen, elevated lactate, and G-6-P) suggesting a catabolic cell state, and an increase in glycogen synthase transformation when compared to the HYPO group. In conclusion, skeletal muscle cell volume alters rates of glucose uptake with further alterations in muscle metabolites and glycogen synthase transformation.

The influence of skeletal muscle cell volume on carbohydrate metabolism in contracting skeletal muscle

This study investigated the regulation of carbohydrate metabolism through changes in skeletal muscle cell volume immediately post contraction and during recovery. Using an established in vitro isolated muscle strip model, soleus (SOL) and extensor digitorum longus (EDL) were dissected from male rats and incubated in an organ bath (perfused with 95% O2; 5% CO2, pH 7.4, temperature 25°C) containing medium- 199 altered to a target osmotic condition (iso-, hypo- or hyper-osmotic; 290, 1 80, 400 mmol/kg). Muscles were stimulated for 10 minutes (40 Hz SOL; 30 Hz EDL) and then either immediately flash frozen or allowed to recover for 20 minutes before subsequent metabolite and enzyme analysis. Results demonstrated a relative water decrease in HYPER vs. HYPOosmotic condition (n=8/group; p<0.05) regardless of muscle type. Specifically, the SOL HYPER condition had elevated metabolite concentrations after 10 minutes of stimulation in comparison to both HYPO and ISO (p<0.05), while EDL muscle did not show any significant difTerences between the HYPER or HYPO conditions. After 20 minutes of recovery, metabolic changes occurred in both SOL and EDL with the SOL HYPER condition showing greater relative changes in metabolite concentrations versus HYPO. The results of the current study have demonstrated that osmotic imbalance induces metabolic change within the skeletal muscle cell and muscle type may influence the mechanisms utilized for cell volume regulation.

Force potentiation in the MDX mouse

Large forces are the primary mechanism of injury in muscular dystrophy, and muscular dystrophy is especially damaging to type IIB muscle fibers. It was hypothesized that post-tetanic potentiation (PTP) would be down-regulated to prevent damage in Xlinked muscular dystrophy (mdx) mice since PTP increases force and PTP effects are greatest in IIB fibers. PTP experiments were performed on the extensor digitorum longus (EDL) of 50 day old mdx (YM) and C57BL/10 (YC) mice and 10 month old mdx (OM) and C57B1710 (OC) mice. Twitch and tetanic forces were lower in mdx than controls and lower in younger than older mice. Contrary to the hypothesis, PTP was higher in both mdx groups compared to controls. OM potentiated more than any other condition (OM: 29.8%, OC: 23.2%, YM: 21.9%, YC: 17.2%). In accordance with literature PTP increased in the older groups. To explain PTP changes, fiber typing and Western blots for myosin light chain kinase (MLCK) were performed. YM and YC had similar fiber type profiles (2% I, 58% IIX/D and 40% IIB). In accordance with literature but contrary to expected conditions for elevated PTP, OM had a slower fiber type profile (1.7% I, 69% IIX/D and 29% IIB) than OC (0.4% I, 61% IIX/D and 38% IIB). No differences were found in MLCK expression. It seems that PTP is up-regulated to maintain muscle function rather than being down-regulated to prevent muscle damage. Ca""^ transient and myosin phosphorylation measurements would be beneficial in explaining increased PTP seen in this study.

The Ontario and St. Lawrence Steamboat Company's hand-book for travelers to Niagara Falls, Montreal and Quebec, and through Lake Champlain to Saratoga Springs.

"Illustrated with maps, and numerous engravings from original sketches."

Modulation of muscle contraction by a FMRFamide-related peptide

A FMRFamide-like neuropeptide with the sequence "DRNFLRF-NH2" was recently isolated from pericardial organs of crayfish (Mercier et aI., Peptides, 14, 137-143, 1993). This neuropeptide, referred to as "DF2'" has already been shown to elicit cardioexcitation and to enhance synaptic transmission at neuromuscular junctions. Possible effects ofDF2 on muscle were investigated using superficial extensor muscles of the abdomen of the crayfish, Procambarus clar/ai. These muscles are of the tonic type and generate slow contractions that affect posture. DF2, at concentrations of 10-8 M or higher, increased muscle tonus and induced spontaneous, rhythmic contractions. These effects were antagonized by 5 rnM Mn2+ but not by lO-7M tetrodotoxin (TTX). Thus, they represent direct actions on muscle cells (rather than effects on motor neurons) and are likely to involve calcium influx. In contrast, deep abdominal extensor muscles, responsible for rapid swimming movements, and superficial flexor muscles do not generate contractions in response to the peptide. 2 Spontaneous contractions were also induced in the superficial extensor muscles by decreasing the temperature to II-13°C. Such contractions were also TTX-insensitive and they were antagonized by adding calcium channel blockers (Mn2+, Cd2+ or Ni2+) or by removing calcium from the bathing solution. This suggests that the spontaneous contractions depend on an influx of calcium from the extracellular solution. N-type and L-type voltage dependent calcium channel blockers did not reduce the effect of the peptide or the spontaneous contractions suggesting that calcium influx is not through N- or L-type calcium channels.