Super-resolution microscopy on single particles at fluid interfaces reveals their wetting properties and interfacial deformations.

Solid particles adsorbed at fluid interfaces are crucial for the mechanical stability of Pickering emulsions. The key parameter which determines the kinetic and thermodynamic properties of these colloids is the particle contact angle, θ. Several methods have recently been developed to measure the contact angle of individual particles adsorbed at liquid-liquid interfaces, as morphological and chemical heterogeneities at the particle surface can significantly affect θ. However, none of these techniques enables the simultaneous visualization of the nanoparticles and the reconstruction of the fluid interface to which they are adsorbed, in situ. To tackle this challenge, we utilize a newly developed super-resolution microscopy method, called iPAINT, which exploits non-covalent and continuous labelling of interfaces with photo-activatable fluorescent probes. Herewith, we resolve with nanometer accuracy both the position of individual nanoparticles at a water-octanol interface and the location of the interface itself. First, we determine single particle contact angles for both hydrophobic and hydrophilic spherical colloids. These experiments reveal a non-negligible dependence of θ on particle size, from which we infer an effective line tension, τ. Next, we image elliptical particles at a water-decane interface, showing that the corresponding interfacial deformations can be clearly captured by iPAINT microscopy.

iPAINT: a general approach tailored to image the topology of interfaces with nanometer resolution.

Understanding interfacial phenomena in soft materials such as wetting, colloidal stability, coalescence, and friction warrants non-invasive imaging with nanometer resolution. Super-resolution microscopy has emerged as an attractive method to visualize nanostructures labeled covalently with fluorescent tags, but this is not amenable to all interfaces. Inspired by PAINT we developed a simple and general strategy to overcome this limitation, which we coin 'iPAINT: interface Point Accumulation for Imaging in Nanoscale Topography'. It enables three-dimensional, sub-diffraction imaging of interfaces irrespective of their nature via reversible adsorption of polymer chains end-functionalized with photo-activatable moieties. We visualized model dispersions, emulsions, and foams with ∼20 nm and ∼3° accuracy demonstrating the general applicability of iPAINT to study solid/liquid, liquid/liquid and liquid/air interfaces. iPAINT thus broadens the scope of super-resolution microscopy paving the way for non-invasive, high-resolution imaging of complex soft materials.

Design, testing, and results of an outcomes-managed approach to patients requiring prolonged mechanical ventilation.

BACKGROUND: Outcomes management that uses critical pathways may decrease costs while improving outcomes for patients who require prolonged mechanical ventilation. OBJECTIVE: To study the efficacy of an outcomes-managed approach to weaning patients from prolonged (more than 3 days) mechanical ventilation. METHODS: A method of multidisciplinary care delivery was designed that included an outcomes manager, a care pathway for patients receiving mechanical ventilation, and weaning protocols. Data collection consisted of three parts: a retrospective review of 124 patients who required prolonged ventilation during a 1-year period before implementation of the care model, a 6-month prospective study in which 91 patients were alternately assigned by month to an outcomes-managed approach or a non-outcomes-managed approach, and a 6-month prospective study of 90 patients in which an outcomes-managed approach without alternate-month assignment was used. RESULTS: Outcomes management had no significant effect on total duration of mechanical ventilation or length of stay in the hospital, days of mechanical ventilation without tracheostomy, days of mechanical ventilation with tracheostomy, or outcome (weaned, withdrawal from mechanical ventilation, death, or transfer without weaning). However, duration of mechanical ventilation was 1.3 days shorter, length of stay in the hospital was 2.1 days shorter, and the cost per case was $ 3341 less for patients in the outcomes-managed group than for patients in the non-outcomes-managed group. CONCLUSION: Outcomes-managed care did not have a significant effect on duration of ventilation, length of stay in the hospital, or outcome in patients receiving long-term mechanical ventilation.

Prevalence of xerophthalmia among children in Beheira governorate, Egypt.

A survey was conducted on a sample representative of the entire Beheira governorate to identify high-risk areas of vitamin A deficiency (VAD) and assess xerophthalmia prevalence. The study also tested the reliability of a household cluster survey for assessing xerophthalmia prevalence. A trained ophthalmologist examined 10,664 children. The results showed that VAD was present in the region, but did not appear to be a public health problem. Ocular signs of VAD were more prevalent among older children, suggesting an improvement in socioeconomic conditions and health care over the past few years. The household cluster survey appeared to be a reliable method for assessing xerophthalmia prevalence in the region.

Effects of mandibular appliances on athletic performance.

This chapter provides a review of the research findings on the role of oral appliances in performance augmentation among athletes. Supporting and non-supporting data are detailed. Evaluation of these data is complicated by the difficulty in establishing objective tests and ruling out subjective reports on strength augmentation among athletes.

An analysis of individual, household, and environmental risk factors for intestinal helminth infection among children in Qena Governorate, Upper Egypt.

During 1994 a cross-sectional survey was carried out on a sample representative of the population in Qena Governorate, Upper Egypt, to investigate the relationship between intestinal helminthic infection among children and a wide range of variables (demographic, behavioural, cultural, socioeconomic, and environmental). Data were collected by direct observation and by administering a questionnaire to mothers in charge of the household in a sample of 768 households representative of the entire population in the governorate. A stool sample survey was conducted at the same time on all children 2-12 years of age living in the selected households (n = 2657). Diagnosis of intestinal helminths was made on the basis of the Kato-Katz thick-smear technique. After univariate analyses, conducted to define associations among individual, familial, and community variables and prevalence of infection, the relevant variables were included in a multivariate logistic model to assess the importance of each factor as an independent determinant of infection. Several factors were independently associated with increased risk of intestinal helminth infection. In particular, the age of the child (between 4 and 5 years) (individual), the age of marriage for the mother (cultural), type of garbage disposal (household), and type of settlement (environmental) gave the highest predictive value for infection. The present results are consistent with those of former studies and highlight the importance of a multisectorial approach in the control of intestinal helminth infection.

Antibacterial drugs in Crohn's disease.

The evidence of a beneficial role of antibacterial drugs in Crohn's disease is largely empirical. Data accumulate to show that these drugs may well be used as an adjunctive therapy to oral anti-inflammatory drugs. Circumstantial evidence has also been provided that antibacterial drugs are effective in relieving symptoms related to bacterial overgrowth and when used for specific indications such as perianal lesions.

Prevalence of xerophthalmia among children in Beheira governorate, Egypt

A survey was conducted on a sample representative of the entire Beheira governorate to identify high-risk areas of vitamin A deficiency [VAD] and assess xerophthalmia prevalence. The study also tested the reliability of a household cluster survey for assessing xerophthalmia prevalence. A trained ophthalmologist examined 10,664 children. The results showed that VAD was present in the region, but did not appear to be a public health problem. Ocular signs of VAD were more prevalent among older children, suggesting an improvement in socioeconomic conditions and health care over the past few years. The household cluster survey appeared to be a reliable method for assessing xerophthalmia prevalence in the region