4,156 research outputs found
A case report on an 8-month infant about zona infection in ocular members due to exposure to intrauterine varicella
Background and aims: Primary varicella infection which is rarely seen among infants appears as chicken pox in children and zona in adults due to its reactivation. Considering its rarity in infants, an 8-month case infected with varicella due to reactivation of intrauterine primary infection is reported. Case report: An 8-month infant with 3200gr weight at a vaginal delivery was hospitalized for erythematous lesion around the left eye, diagnosed as orbital cellulitis initially. The lesion spread rapidly to 8×14cm and several fluid -filled vesicules (which then turned into yellow) developed. Referring to case history, the mother was infected to varicella with generalized macrovesicular lesions involving stomach, face, and limbs. Infant tests of varicella zoster virus about the existence of immunoglobulin M were positive. Treatment was done by cephalotine, acyclovir, and sulfacetamide eye drop. The lesions disappeared within one week. Conclusion: In this patient, because of exposure to varicella infection in utero period, reactivation of primary infection after birth in 8-month appeared herpes zoster symptoms. After diagnosis, the treatment was successful
Correlation of transcutaneous and serum bilirubin levels in infants with neonatal jaundice hospitalized in Hajar Hospital in Shahrekord
Background and Aim: Bilirubin level measurement through BiliCheck device can be a useful method in diagnosing neonatal jaundice due to no need for frequent blood-taking. Thus, the present study aimed to compare serum and transcutaneous bilirubin levels in infants with neonatal jaundice hospitalized in Hajar Hospital in Shahrekord. Materials and Methods: In this descriptive-correlation study, 417 infants with neonatal jaundice were examined. A questionnaire including demographic information (age and weight of infant at the time of reception, weight at the time of birth, age of pregnancy, and infant sex) was completed. As the infants were hospitalized, the blood-taking were done to control serum bilirubin based on the routine stages of the unit and transcutaneous Bilirubin level was controlled by BiliCheck device and the data were recorded. Pearson coefficient and independent t-test statistical analysis were used through SPSS software. Results: From the total of 417 infants under this study, 322 infants were term and 95 infants were preterm. 51.3% were male and 48.7% were female. Weight average of term infants was 3081467.88 and in the preterm infants, it was 2335572.44 gram. The results indicated the linear coefficient was direct and meaningful between the serum and transcutaneous bilirubin levels in term and preterm infants. Conclusion: The findings suggested that mean difference of bilirubin levels on these two methods of measurement in term infants in different days were meaningful while there is no significant mean difference in preterm infants indicating the efficacy of this device in measuring bilirubin levels in preterm infants
An ab initio supercell approach for high-harmonic generation in liquids
Many important ultrafast phenomena take place in the liquid phase. However, there is no practical theory to predict how liquids respond to intense light. Here, we propose an ab initio accurate method to study the non-perturbative interaction of intense pulses with a liquid target to investigate its high-harmonic emission. We consider the case of liquid water, but the method can be applied to any other liquid or amorphous system. The liquid water structure is reproduced using Car-Parrinello molecular dynamics simulations in a periodic supercell. Then, we employ real-time time-dependent density functional theory to evaluate the light-liquid interaction. We outline the practical numerical conditions to obtain a converged response. Also, we discuss the impact of nuclei ultrafast dynamics on the non-linear response of system. In addition, by considering two different ordered structures of ice, we show how harmonic emission responds to the loss of long-range order in liquid water
Ab Initio Cluster Approach for High Harmonic Generation in Liquids
High harmonic generation (HHG) takes place in all phases of matter. In gaseous atomic and molecular media, it has been extensively studied and is very well understood. In solids, research is ongoing, but a consensus is forming for the dominant microscopic HHG mechanisms. In liquids, on the other hand, no established theory yet exists, and approaches developed for gases and solids are generally inapplicable, hindering our current understanding. We develop here a powerful and reliable ab initio cluster-based approach for describing the nonlinear interactions between isotropic bulk liquids and intense laser pulses. The scheme is based on time-dependent density functional theory and utilizes several approximations that make it feasible yet accurate in realistic systems. We demonstrate our approach with HHG calculations in water, ammonia, and methane liquids and compare the characteristic response of polar and nonpolar liquids. We identify unique features in the HHG spectra of liquid methane that could be utilized for ultrafast spectroscopy of its chemical and physical properties, including a structural minimum at 15–17 eV that is associated solely with the liquid phase. Our results pave the way to accessible calculations of HHG in liquids and illustrate the unique nonlinear nature of liquid systems
Study of chemical and physical behavior cotton fabrics treated by corona discharge after several laundering
Cotton fabric because of finishing process has shrinkage behavior after laundering and for improving this problem, chemical agents utilize for anti-shrinkage. This temporary finishing can reduce shrinkagebut has many environmental problems. Corona discharge treatment has been used for cotton fabric, other fibers and polymers. This treatment can reduce costs and environmental impacts. In this study, cotton fabric was treated by corona discharge instrument at 2 - 40 passages and fabrics were washed with laundering method. After four times laundering, shrinkage behavior of corona discharge treated fabric as compared with un-treated fabric decrease. After 10 passages of corona discharge treatment,water, dye absorption and shrinkage are modified but after 14 passages, despite of shrinkage improvement, dyeing properties decrease
The Lateral Migration of a Drop under Gravity between Two Parallel Plates at Finite Reynolds Numbers
A finite difference / front tracking method is used to examine the lateral migration of a three-dimensional deformable
drop in plane Poiseuille flow at a finite-Reynolds-number. The computations are based on an improved
implementation of the front tracking method at finite Reynolds numbers that include convective terms. The elliptic
pressure equation is solved by a multigrid method. Both neutrally buoyant and non-neutrally buoyant drop are
studied. The computation is performed within a unit cell which is periodic in the direction along the channel. A
neutrally buoyant drop lags the fluid slightly, and the wall effect balances the effect of the curvature of the velocity
profile, giving rise to an equilibrium lateral position about halfway between the wall and the centerline (the Segre-
Silberberg effect). Results are presented over a range of density ratios. In the non-neutrally buoyant case, the gravity
force is imposed along the flow direction. Non-neutrally buoyant drops have more complicated patterns of migration,
depending upon the magnitude of the buoyancy force. When the density difference is small, the equilibrium position is
either near the wall or near the centerline, depending on whether the drop leads or lags the local fluid. When the
density difference is large enough, the equilibrium position shifts towards the centerline, irrespective of whether the
drop is lighter or heavier than the fluid. The effect of Reynolds number and capillary number on the non-neutrally
buoyant drops is investigated. The accuracy of the method is assessed by comparison with the other simulations and
experiments
Acylated ghrelin, growth hormone and IGF-1 levels in the cord blood of small for gestational age newborns
Background: Ghrelin is a pleiotropic hormone that regulates feeding and energy balance and stimulates growth hormone release. Ghrelin also exerts developmental and organizational effects during prenatal life. Objectives: The aim of this study was to determine ghrelin levels in cord blood of small for gestational age (SGA) infants and its association with GH (growth hormone) and IGF-1 levels (insulin-like growth factor-1). Methods: Cord blood sample was obtained from 31 SGA and 25 appropriate for gestational age (AGA) infants. Acylated ghrelin, GH, and IGF-1 levels were measured by enzyme-linked immunosorbent assay. Results: No significant differences were observed in ghrelin and GH concentrations between SGA and AGA infants. However, IGF-1 levels were significantly lower in SGA infants. Cord blood ghrelin was negatively correlated with the infants' birth weight (r = -0.33, P = 0.013); on the other hand, IGF-1 level was positively correlated with birth weight (r = 0.43, P = 0.002). Conclusions: IGF-1 has the most significant effect on intrauterine growth. Acylated ghrelin is detectable in cord blood and correlated with birth weight, suggesting a role in intrauterine development, but its level is not affected by intrauterine growth retardation. © 2016, Iranian Society of Pediatrics
Probing the low-energy electron-scattering dynamics in liquids with high-harmonic spectroscopy
High-harmonic spectroscopy (HHS) is a nonlinear all-optical technique with inherent attosecond temporal resolution, which has been applied successfully to a broad variety of systems in the gas phase and solid state. Here, we extend HHS to the liquid phase, and uncover the mechanism of high-harmonic generation (HHG) for this phase of matter. Studying HHG over a broad range of wavelengths and intensities, we show that the cut-off (Ec) is independent of the wavelength beyond a threshold intensity, and find that Ec is a characteristic property of the studied liquid. We explain these observations within an intuitive semi-classical model based on electron trajectories that are limited by scattering to a characteristic length, which is connected to the electron mean-free path. Our model is validated against rigorous multi-electron time-dependent density-functional theory calculations in, both, supercells of liquid water with periodic boundary conditions, and large clusters of a variety of liquids. These simulations confirm our interpretation and thereby clarify the mechanism of HHG in liquids. Our results demonstrate a new, all-optical access to effective mean-free paths of slow electrons (≤10 eV) in liquids, in a regime that is inaccessible to accurate calculations, but is critical for the understanding of radiation damage to living tissue. Our work also establishes the possibility of resolving sub-femtosecond electron dynamics in liquids, which offers a novel, all-optical approach to attosecond spectroscopy of chemical processes in their native liquid environment
Flow Pattern Analysis and Performance Improvement of Regenerative Flow Pump Using Blade Geometry Modification
Regenerative pump is a low specific speed and rotor-dynamic turbomachine capable of developing high heads at low flow rates. In this paper, a numerical study has been carried out in order to investigate the effect of blade angle on the performance of a regenerative pump. Two groups of impellers were employed. The first type has symmetric angle blades with identical inlet/outlet angles of ±10°, ±30°, and ±50° and the second group has nonsymmetric angle blades in which the inlet angle was set to 0° and six different angles of ±10°, ±30°, and ±50° were designed for the outlet of the blades. A total of 12 impellers, as well as primary radial blades impeller, were investigated in this study. The results showed that all forward blades have higher head coefficients than radial blades impeller at design flow coefficient. It was found that regenerative pumps with symmetric angle forward blades have better performance than other types. Also, it is worth mentioning that the highest head coefficient and efficiency occur at angle +10<β<+30 of symmetric angle blades. It was found that the maximum efficiency occurs at angle of +15.5° by curve fitting to the data obtained from numerical simulations for symmetric angle forward blades
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