107 research outputs found
Impact of inhaled corticosteroids on growth in children with asthma: systematic review and meta-analysis
Background: Long-term inhaled corticosteroids (ICS) may reduce growth velocity and final height of children with asthma. We aimed to evaluate the association between ICS use of >12 months and growth. Methods: We initially searched MEDLINE and EMBASE in July 2013, followed by a PubMed search updated to December 2014. We selected RCTs and controlled observational studies of ICS use in patients with asthma. We conducted random effects meta-analysis of mean differences in growth velocity (cm/year) or final height (cm) between groups. Heterogeneity was assessed using the I2 statistic. Results: We found 23 relevant studies (twenty RCTs and three observational studies) after screening 1882 hits. Meta-analysis of 16 RCTs showed that ICS use significantly reduced growth velocity at one year follow-up (mean difference -0.48 cm/year (95% CI -0.66 to -0.29)). There was evidence of a dose-response effect in three RCTs. Final adult height showed a mean reduction of -1.20 cm (95% CI -1.90 cm to -0.50 cm) with budesonide versus placebo in a high quality RCT. Meta-analysis of two lower quality observational studies revealed uncertainty in the association between ICS use and final adult height, pooled mean difference -0.85 cm (95% CI -3.35 to 1.65). Conclusion: Use of ICS for >12 months in children with asthma has a limited impact on annual growth velocity. In ICS users, there is a slight reduction of about a centimeter in final adult height, which when interpreted in the context of average adult height in England (175 cm for men and 161 cm for women), represents a 0.7% reduction compared to non-ICS users
Pressure-induced Miscibility Increase of CH4 in H2O: A Computational Study Using Classical Potentials
Methane and water demix under normal (ambient) pressure and temperature conditions, due to the polar nature of water and the apolar nature of methane. Recent experimental work has shown, though, that increasing the pressure to values between 1 and 2 GPa (10 to 20 kbar) leads to a marked increase of methane solubility in water, for temperatures which are well below the critical temperature for water. Here we perform molecular dynamics simulations based on classical force fields – which are well-used and have been validated at ambient conditions – for different values of pressure and temperature. We find the expected increase in miscibility for mixtures of methane and supercritical water; however our model fails to reproduce the experimentally observed increase in methane solubility at large pressures and below the critical temperature of water. This points to the need to develop more accurate force fields for methane and
methane-water mixtures under pressure
SEPARATION OF CHOPPED NETTLE MATERIAL ON PLANE SIEVE LENGTH
The paper presents the results of several experimental researches regarding to a separation mixture of dried and chopped nettle fragments on a dimensional separator of medicinal plants, equipped with oscillating flat sieves. Three parameters were varied (material flow rate, sieves angle of inclination and oscillations sieves frequency). For separation process description along chopped vegetal material sieves, the experimental results have been tested by Rosin-Rammler distribution law
THE ANALYSIS OF HEAVY METALS CONTENT IN WHOLE AND CHOPPED PLANTS
This paper presents the results of experimental research performed to analyze thepotentially contain of heavy metals in whole and chopped herbs, in order to examine the influence of the cutting process on bioaccumulation of metals in studied plant material
HARVESTING TECHNOLOGIES FOR MEDICINAL AND AROMATIC PLANTS
In recent years, the people had more and more the tendency to return to remedies offered by nature. Nowadays, according to W.H.O. data, over 80% out of world population is using the medicinal plants for which a great interest was generated by traditional phytotherapy and especially by the fact that they represent an important source of bioactive substances. Therefore, the fields cultivated with medicinal plants have been extended and the relevant culture technologies have been modernized and adapted to current requirements. In general, mechanized harvesting of medicinal and aromatic plants is an important prerequisite in achieving a good production. Lavender is one of the most valuable aromatic species due to its volatile oil obtained by distillation of fresh inflorescences, being widely used in industry of perfume, cosmetics, pharmaceuticals, aromatherapy, etc. Harvesting technologies of lavender and medicinal plants require specialized equipment designed according to cultivated field size. This paper presents a lavender harvesting technology, based on the utilization of a low-capacity equipment designed to gather the lavender from rather reduced surfaces. At the same time, a technology of harvesting medicnal plants, from which aerial organs (stems, leaves, flowers) are collected, is presented together with the small capacity equipment used for this purpose. This equipment was designed in order to support small farmers, for whom lavender and other medicinal species cultivation (from which the herb is capitalized) represents a real opportunity for obtaining major incomes
CONSTRUCTION TYPES OF TECHNICAL EQUIPMENT FOR DOSING, WEIGHING, PACKAGING AND PROCEDURES USED IN MILLING UNITS
The paper presents several types of technical equipment for dosing, weighing, packaging and the procedures used in the milling units. The weighing systems take into account several important criteria for their design, namely: how the weight or mass of the load is offset and how the result is transferred
RESEARCHES ON SOIL CONTAMINATION WITH HEAVY METALS AND THEIR REMANENCE IN VEGETABLES
The paper presents the results of experimental researches on soil contamination with heavy metals (copper, lead, zinc) in different concentration each (c1=1.5 %; c2=3.0 %; c3=4.5 %; c4=6.0 %). The contaminated soil was placed in pots, where spinach and radish seeds were planted. The vegetables were grown in a greenhouse until the end of the vegetation period, afterwards being harvested and the remanence of each heavy metal for each concentration was determined for each plant. The results obtained were compared with the blank sample where the soil was not contaminated. The purpose of the study was to identify the levels of heavy metals (Cu, Zn and Pb) transfer/absorption from the soil into spinach leaves respectively radish roots
Radiation attenuation by single-crystal diamond windows
As artificial diamond becomes more cost effective it is likely to see increasing use as a window for sample environment equipment used in diffraction experiments. Such windows are particularly useful as they exhibit exceptional mechanical properties in addition to being highly transparent to both X-ray and neutron radiation. A key application is in high-pressure studies, where diamond anvil cells (DACs) are used to access extreme sample conditions. However, despite their utility, an important consideration when using single-crystal diamond windows is their interaction with the incident beam. In particular, the Bragg condition will be satisfied for specific angles and wavelengths, leading to the appearance of diamond Bragg spots on the diffraction detectors but also, unavoidably, to loss of transmitted intensity of the beam that interacts with the sample. This effect can be particularly significant for energy-dispersive measurements, for example, in time-of-flight neutron diffraction work using DACs. This article presents a semi-empirical approach that can be used to correct for this effect, which is a prerequisite for the accurate determination of diffraction intensities
ASPECTS ON THE CONSTRUCTION AND OPERATION OF SPRAYING EQUIPMENT FOR REDUCING DRIFT IN FIELD CROPS
The paper presents innovative solutions on the construction si operation of spraying machines in the view of reducing drift in field crops: with innovative electrostatic spraying system, with special panels with static condenser, nozzle protection system, spraying devices provided with hoods, downward air curtain system and with shielded system with caps for controlling drop dispersion. The paper is important, on the one hand, for producers of spraying equipment for reducing drift and, on the other hand, for farmers in the view of efficiently applying treatments in field crops, but also for reducing environmental pollution
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