Nutritional management and weight changes during hospitalization of Brazilian infants with diarrhoea: Primary reliance on oral feeding or continuous nasogastric drip with locally made, modulated minced chicken formula

The nutritional management of infants admitted with diarrhoea to the University Hospital of Botucatu includes a change from bolus feeding of a modulated minced-chicken formula to a continuous nasogastric drip (NGD) feeding, whenever the required calorie intake is not achieved or the diarrhoea does not subside. To evaluate this approach, the clinical course and weight changes of 63 children, aged 1-20 months, were reviewed; most (81 per cent) were below the third percentile for weight at admission and 76 per cent had a total duration of diarrhoea ≥10 days. Associated infections, mainly systemic, were present at or after admission in 70 per cent of them. Twenty-five survivors needed nutritional support (NS), predominantly NGD, for a median duration of 30 per cent of their admission time, and were compared to 31 survivors managed without NS. Those who necessitated NS lost weight for a significantly longer median time (12x4 days, p<0.005), but their total weight loss was similar (5x4 per cent) as well as diarrhoea's duration (8x7 days). There was a tendency for a longer hospitalization (21x16 days 0.05

New family of zero-current-switching PWM converter

A new family of dc-to-dc pulse-width-modulated (PWM) converters is presented. These converters feature soft-commutation at zero-current (ZC) in the active switches. The new ZCS-PWM Boost and new ZCS-PWM Zeta converters, both based on the new ZCS-PWM soft-commutation cell proposed, are used as examples to illustrate the operation of the new family of converters.

Dimmable electronic ballast with high power-factor SEPIC preregulator, for multiple tubular fluorescent lamps

An electronic ballast for multiple tubular fluorescent lamps is presented in this paper. The proposed structure features high power-factor, dimming capability, and soft-switching to the semiconductor devices operated in high frequencies. A Zero-Current-Switching - Pulse-Width-Modulated (ZCS-PWM) SEPIC converter composes the rectifying stage, controlled by the instantaneous average input current technique, performing soft-commutations and high input power factor. Regarding the inverting stage, it is composed by a classical resonant Half-Bridge converter, associated to Series Parallel-Loaded Resonant (SPLR) filters. The dimming control technique employed in this Half-Bridge inverter is based on the phase-shift in the current processed through the sets of filter + lamp. In addition, experimental results are shown in order to validate the developed analysis.

Vertical and in-plane electrical transport in InAs/InP semiconductor nanostructures

Vertical and in-plane electrical transport in InAs/InP semiconductors wires and dots have been investigated by conductive atomic force microscopy (C-AFM) and electrical measurements in processed devices. Localized I-V spectroscopy and spatially resolved current images (at constant bias), carried out using C-AFM in a controlled atmosphere at room temperature, show different conductances and threshold voltages for current onset on the two types of nanostructures. The processed devices were used in order to access the in-plane conductance of an assembly with a reduced number of nanostructures. On these devices, signature of two-level random telegraph noise (RTN) in the current behavior with time at constant bias is observed. These levels for electrical current can be associated to electrons removed from the wetting layer and trapped in dots and/or wires. A crossover from conduction through the continuum, associated to the wetting layer, to hopping within the nanostructures is observed with increasing temperature. This transport regime transition is confirmed by a temperature-voltage phase diagram. © 2005 Materials Research Society.

Reversible holographic 3D data storage in oxide glasses using visible lasers

Antimony based glasses have been investigated for the first time regarding the possibility of holographic data storage using visible lasers sources. Changes in both refractive index and the absorption coefficient were measured using a holographic setup. The modulation of the optical constants is reversible by heat treatment. Bragg gratings were written under visible light of an Ar laser and erased thermally.

Effect of the Rashba and Dresselhaus spin-splitting terms on the electron g factor in semiconductor quantum wells under applied magnetic fields

We use the Ogg-McCombe Hamiltonian together with the Dresselhaus and Rashba spin-splitting terms to find the g factor of conduction electrons in GaAs-(Ga,Al)As semiconductor quantum wells (QWS) (either symmetric or asymmetric) under a magnetic field applied along the growth direction. The combined effects of non-parabolicity, anisotropy and spin-splitting terms are taken into account. Theoretical results are given as functions of the QW width and compared with available experimental data and previous theoretical works. © 2007 Elsevier B.V. All rights reserved.

In vitro assessment of pulp chamber temperature of different teeth submitted to dental bleaching associated with LED/laser and halogen lamp appliances

This study sought to assess the pulp chamber temperature in different groups of human teeth that had been bleached using hydrogen peroxide gel activated with halogen lamps or hybrid LED/laser appliances. Four groups of ten teeth (maxillary central incisors, mandibular incisors, mandibular canines, and maxillary canines) were used. A digital thermometer with a K-type thermocouple was placed inside pulp chambers that had been filled with thermal paste. A 35% hydrogen peroxide-based red bleaching gel was applied to all teeth and photocured for a total of three minutes and 20 seconds (five activations of 40 seconds each), using light from an LED/laser device and a halogen lamp. The temperatures were gauged every 40 seconds and the data were analyzed by three-way ANOVA, followed by Tukey's test. Regardless of the light source, statistically significant differences were observed between the groups of teeth. The mean temperature values (±SD) were highest for maxillary central incisors and lowest for mandibular canines. The halogen lamp appliance produced more pulp chamber heating than the LED/laser appliance. The increase in irradiation time led to a significant increase in temperature.

Using state-space techniques to represent frequency dependent single-phase lines directly in time domain

This paper proposes to use a state-space technique to represent a frequency dependent line for simulating electromagnetic transients directly in time domain. The distributed nature of the line is represented by a multiple 1t section network made up of the lumped parameters and the frequency dependence of the per unit longitudinal parameters is matched by using a rational function. The rational function is represented by its equivalent circuit with passive elements. This passive circuit is then inserted in each 1t circuit of the cascade that represents the line. Because the system is very sparse, it is possible to use a sparsity technique to store only nonzero elements of this matrix for saving space and running time. The model was used to simulate the energization process of a 10 km length single-phase line. ©2008 IEEE.

Mutual coupling modeling in transmission lines directly in the phase domain

This paper describes a computational model based on lumped elements for the mutual coupling between phases in three-phase transmission lines without the explicit use of modal transformation matrices. The self and mutual parameters and the coupling between phases are modeled using modal transformation techniques. The modal representation is developed from the intrinsic consideration of the modal transformation matrix and the resulting system of time-domain differential equations is described as state equations. Thus, a detailed profile of the currents and the voltages through the line can be easily calculated using numerical or analytical integration methods. However, the original contribution of the article is the proposal of a time-domain model without the successive phase/mode transformations and a practical implementation based on conventional electrical circuits, without the use of electromagnetic theory to model the coupling between phases. © 2011 IEEE.

In vitro effect of low-level laser therapy on typical oral microbial biofilms

The aim of this study was to evaluate the effect of specific parameters of low-level laser therapy (LLLT) on biofilms formed by Streptococcus mutans, Candida albicans or an association of both species. Single and dual-species biofilms - SSB and DSB - were exposed to laser doses of 5, 10 or 20 J/cm 2 from a near infrared InGaAsP diode laser prototype (LASERTable; 780 ± 3 nm, 0.04 W). After irradiation, the analysis of biobilm viability (MTT assay), biofilm growth (cfu/mL) and cell morphology (SEM) showed that LLLT reduced cell viability as well as the growth of biofilms. The response of S. mutans (SSB) to irradiation was similar for all laser doses and the biofilm growth was dose dependent. However, when associated with C. albicans (DSB), S. mutans was resistant to LLLT. For C. albicans, the association with S. mutans (DSB) caused a significant decrease in biofilm growth in a dose-dependent fashion. The morphology of the microorganisms in the SSB was not altered by LLLT, while the association of microbial species (DSB) promoted a reduction in the formation of C. albicans hyphae. LLLT had an inhibitory effect on the microorganisms, and this capacity can be altered according to the interactions between different microbial species.

A transmission line model developed directly in phase domain

The phases of a transmission line are tightly coupled due to mutual impedances and admittances of the line. One way to accomplish the calculations of currents and voltages in multi-phase lines consists in representing them in modal domain, where its n coupled phases are represented by their n propagation modes. The separation line in their modes of propagation is through the use of a modal transformation matrix whose columns are eigenvectors associated with the parameters of the line. Usually, this matrix is achieved through numerical methods which do not allow the achievement of an analytical model for line developed directly in the phases domain. This work will show an analytical model for phase currents and voltages of the line and results it will be applied to a hypothetical two-phase. It will be shown results obtained with that will be compared to results obtained using a classical model. © 2012 IEEE.

Development of a simplified transmission line model directly in the phase domain

A transmission line digital model is developed direct in the phase and time domains. The successive modal transformations considered in the three-phase representation are simplified and then the proposed model can be easily applied to several operation condition based only on the previous knowing of the line parameters, without a thorough theoretical knowledge of modal analysis. The proposed model is also developed based on lumped elements, providing a complete current and voltage profile at any point of the transmission system. This model makes possible the modeling of non-linear power devices and electromagnetic phenomena along the transmission line using simple electric circuit components, representing a great advantage when compared to several models based on distributed parameters and inverse transforms. In addition, an efficient integration method is proposed to solve the system of differential equations resulted from the line modeling by lumped elements, thereby making possible simulations of transient and steady state using a wide and constant integration step. © 2012 IEEE.

Dentin hypersensitivity after teeth bleaching with in-office systems. randomized clinical trial

Purpose: To comparatively and prospectively compare in a randomized clinical trial, dentin hypersensitivity after treatment with three in-office bleaching systems, based on hydrogen peroxide at different concentrations, with and without light source activation. Methods: 88 individuals were included according to inclusion and exclusion criteria. Subjects were randomly divided into the following three treatment groups: Group 1 was treated with three 15-minute applications of hydrogen peroxide at 15% with titanium dioxide (Lase Peroxide Lite) that was light-activated (Light Plus Whitening Lase) with five cycles of 1 minute and 30 seconds each cycle, giving a total treatment time of 45 minutes; Group 2 was treated with three 10-minute applications of hydrogen peroxide at 35% (Lase Peroxide Sensy), activated by light (LPWL) same activation cycles than Group 1, with a total treatment time of 30 minutes; Group 3 was treated with only one application for 45 minutes of hydrogen peroxide at 35% (Whitegold Office) without light activation. Each subject underwent one session of bleaching on the anterior teeth according to the manufacturers' instructions. Dentin sensitivity was recorded with a visual analogue scale (VAS) at baseline, immediately after, and at 7 and 30 days after treatment using a stimulus of an evaporative blowing triple syringe for 3 seconds on the upper central incisors from a distance of 1 cm. A Kruskal-Wallis test followed by Mann-Whitney test was performed for statistical analysis. Results: All groups showed increased sensitivity immediately after treatment. Group 1 displayed less changes relative to baseline with no significant differences (P= 0.104). At 7 and 30 days after treatment, a comparison of VAS values indicated no significant differences between all groups (P= 0.598 and 0.489, respectively).

A 12-month follow-up of hypopigmentation after laser hair removal

Introduction: Laser hair removal is becoming an increasingly popular alternative to traditional methods such as shaving, waxing, among other methods. Semiconductor diode lasers are considered the most efficient light sources available and are especially well suited for clinical applications including hair reduction. The effectiveness of laser hair reduction depends on many variables, including the skin type of the patient. Material and Methods: A patient with Fitzpatrick Skin Type IV was submitted to laser hair removal of the arms with a high-power diode laser system with long pulses with a wavelength of 800 nm, a fluence of 40 J/cm2 and a pulse width of 20 ms. A 12-month follow-up assessment was performed and included photography and questionnaire. Results: Hypopigmentation was observed after a single laser hair removal section. After 6 months with the area totally covered, a gradual suntan with a sun screen lotion with an SPF of 15 was prescribed by the dermatologist. After 12 months of the initial treatment, a complete recovery of the hypopigmentation was achieved. Conclusion: Although a safe procedure, lasers for hair removal may be associated with adverse side effects including undesired pigment alterations. Before starting a laser hair removal treatment, patients seeking the eradication of hair should be informed that temporary, and possibly permanent, pigmentary changes may occur. © 2013 Informa UK, Ltd.