Can school teachers improve the management and prevention of skin disease? A pilot study based on head louse infestations in Guerrero, Mexico

BACKGROUND: The effect of health education provided by teachers, in three primary schools of Guerrero, Mexico, on the prevalence of head louse infestation was compared. METHODS: A cross-sectional survey and rapid appraisal methods were performed, including a child questionnaire and qualitative data from teachers and focus groups of mothers in the same schools. RESULTS: Nine hundred and forty-four students and 33 teachers were interviewed; a focus group discussion with 6-8 mothers per school was performed. In the self-diagnosis of pediculosis, the prevalence was 22% (range, 18%-33%) with a sensitivity of 68% and a specificity of 86%. In one school, 100% of the teachers applied a health program, whereas in the other two schools this percentage was only 20%. A child under 9 years of age who attended a school without information on health was 3.6 times more likely to have head louse infestation (OR = 3.6, CI 95% = 2.1-6) than a child of the same age who attended a school where information was given. In older children the effect and potential impact were lower. The difference between the two age groups is unlikely to be explained by chance (X2 het = 5.7, df = 1, p = 0.01). CONCLUSIONS: This study emphasizes the potential value of simple, but effective, health education provided by school teaching staff through liaison with patents in the amelioration of endemic disease.     

A method to extract mobility degradation and total seriesresistance of fully-depleted SOI MOSFETs

Free-carrier mobility degradation in the channel and drain/source series resistance are two important parameters limiting the performance of MOS devices. In this paper, we present a method to extract these parameters from the drain current versus gate voltage characteristics of fully-depleted (FD) SOI MOSFETs operating in the saturation region. This method is developed based on an integration function which reduces errors associated with the extraction procedure and on the DC characteristics of MOS devices having several different channel lengths. Simulation results and measured data of FD SOI MOSFETs are used to test and verify the method developed     

Functional Chromatography Reveals Three Natural Products that Target the Same Protein with Distinct Mechanisms of Action

Access to lead compounds with defined molecular targets continues to be a barrier to the translation of natural product resources. As a solution, we developed a system that uses discrete, recombinant proteins as the vehicles for natural product isolation. Here, we describe the use of this functional chromatographic method to identify natural products that bind to the AAA+ chaperone, p97, a promising cancer target. Application of this method to a panel of fungal and plant extracts identified rheoemodin, 1‐hydroxydehydroherbarin, and phomapyrrolidone A as distinct p97 modulators. Excitingly, each of these molecules displayed a unique mechanism of p97 modulation. This discovery provides strong support for the application of functional chromatography to the discovery of protein modulators that would likely escape traditional high‐throughput or phenotypic screening platforms.     

Characterization of MIS structures and PTFTs using TiOx deposited by spin-coating

This paper presents a method to deposit titanium oxide (TiOx) films from a sol containing IV titanium isopropoxide Ti[OCH(CH₃)₂]₄, 2-methoxyethanol, CH₃OCH₂CH₂OH and ethanolamine H₂NCH₂CH₂OH, in order to obtain layers with thickness above 220 nm with the required characteristics to be used in Metal–Insulator–Semiconductor, MIS, structures and polymeric thin film transistors, PTFTs. The effect of using different component ratios is described. The dielectric constant was in the order of 12, the critical electric field was 5 × 10⁵ V/cm and the density of states at the interface was less than 1 × 10¹¹ cm⁻². The analysis of MIS structures prepared with these TiOx layers shows that they are suitable for using in PTFTs. The fabrication of independent bottom gate PTFTs with poly(3-hexylthiophene), P3HT, on top of the TiOx layer is described, obtaining a major reduction in the operation voltage range from −30 V to −4 V, while maintaining the typical mobility for P3HT PTFTs.     

Transient heat conduction in a glass with chemically deposited SnS---CuxS solar control coating

The transient thermal performance of a chemically deposited thin film on a glass substrate is presented. Differential energy balances for the glass are set up assuming a one-dimensional transient state for normal incidence of the air mass to solar radiation. Using the reported properties of a SnS-Cu_xS thin film as a specific example, the net energy flow through a glass and the specific film were calculated for a time period. The effect of absorption in the film is specifically considered. The theoretical time histories of the surface temperatures of the glass plus solar control coating and the clear glass are plotted for an exterior temperature range of 0–50°C. The redistribution to the interior and exterior of the absorbed component of the solar radiation as well as the shading coefficient in time are evaluated for a constant convective heat transfer coefficient for ambient temperatures of 30 and 20°C. Also, the time constant of the system is given.     

Synthesis and characterization of rough electrochromic phosphotungstic acid films obtained by spray-gel process

Rough electrochromic phosphotungstic acid (PWA) films were fabricated by spraying a gel of phosphotungstate anions with a molar ratio of P:W=1:12 onto glass substrates. The substrates were coated with transparent and electrically conducting SnO₂:F at 300°C. Analysis by X-ray photoelectron spectroscopy determined that the P:W molar ratio in the films was approximately 1:14. Infrared spectroscopy and X-ray diffraction showed that the film is a form of polycrystalline phosphotungstic acid. SEM micrographs showed that the films have a rough morphology based on fiber-shape bridges. Optoelectrochemical measurements demonstrated pronounced electrochromism in the PWA films upon H⁺ intercalation/deintercalation with a high diffuse reflectance (R_d) and transmittance (T_d). We found for as-deposited films that R_d/total reflectance (R_t) and T_d/total transmittance (T_t) at 550 nm was around 0.83 and 0.68, respectively. This ratio decreases at bleached state to 0.74 and 0.41 for R_d/R_t and T_d/T_t, respectively.     

The danger of high-frequency spurious effects on wide microstrip line

It has been found that remarkably severe spurious effects can occur in the current excited on microstrip line at moderate to high frequency, when the strip is wide (approximately w/h > 3). This newly observed effect occurs because one or more leaky modes (LMs) approaches the branch point at k/sub 0/ in the complex longitudinal wavenumber plane. When this happens, the attenuation (leakage) constant of these LMs becomes very small. Hence, the LMs can propagate to very large distances along the line with only minimal attenuation. This effect only occurs when the strip is fairly wide, and at certain frequencies. When it occurs, the effect can be disastrous since the continuous-spectrum (radiation) part of the current on the strip then decays very slowly with distance from the source so that the total strip current excited by the source exhibits spurious oscillations out to very large distances from the source. An approximate design rule for predicting this effect is given, which is accurate for wide strips (approximately w/h > 6). The LMs that are responsible for this effect are identified, and the behavior of these modes are studied for different strip widths.     

Mobile thrombus in the right cardiac cavities in patients with severe pulmonary thromboembolism. Importance of echocardiography

The pulmonary thromboembolism is a frequent and severe disease, usually difficult to recognize, specially in patients with thrombotic material trapped within right heart cavities. We present our experience in three patients with severe pulmonary thromboembolism where echocardiographic study demonstrated the presence of huge mobile thrombus in right heart cavities, which demanded urgent therapy with excellent results. We would like to stress that echocardiographic study in these patients could be elective diagnostic procedure, avoiding the realization of pulmonary arteriography, which could bring risk of possible thrombus mobilization.     

FD MOS SOI circuit to enhance the ratio of illuminated to dark current of a co-integrated a-Si:H photodiode

In this paper we first present the integration of amorphous silicon photodiodes with a fully depleted silicon on isolator (FD SOI) MOSFET circuit. Taking the advantage of the better subthreshold characteristic of FD SOI MOSFETs with respect to bulk devices, a very simple SOI circuit integrated with the amorphous silicon photodiode is presented to significantly improve the ratio of the circuit output current when the diode is illuminated to when it is not. The use of one additional reference source voltage to adjust the operating point of the photodiode, allows to obtain a very significant increase in this current ratio, much higher than what can be obtained using a simple diode. Circuit solutions used to amplify the diode current under illumination are usually more complicated and involve a capacitor or more transistors than the circuit we present. All the other properties of the photodetector, as its spectral characteristic and linear dependence of detection with light intensity are maintained. The circuit can also be used in conjunction with other circuits for further amplification and/or processing.