Abstract
Background
Health promotion in the workplace is intended to enhance employee health and well-being. Yoga programmes are easy to implement and have been effective in the management of various ...health conditions.
Aims
To assess the evidence regarding the effectiveness of yoga programmes at work.
Methods
A search of electronic databases of published studies up until the 1st of April 2017. Inclusion criteria for the systematic review were randomized controlled trials of adult employees and yoga in the workplace. Quality appraisal was carried out using the Cochrane Collaboration’s tool for assessing risk of bias in randomized trials.
Results
Of 1343 papers identified, 13 studies met the inclusion criteria. Nine out of 13 trials were classified as having an unclear risk of bias. The overall effects of yoga on mental health outcomes were beneficial, mainly on stress. Most of the cardiovascular endpoints showed no differences between yoga and controls. Other outcomes reported positive effects of yoga or no change.
Conclusions
The findings of this study suggest that yoga has a positive effect on health in the workplace, particularly in reducing stress, and no negative effects were reported in any of the randomized controlled trials. Further larger studies are required to confirm this.
A novel approach to provide, thermally sensitive neutral solutions based on chitosan/polyol salt combinations is described. These formulations possess a physiological pH and can be held liquid below ...room temperature for encapsulating living cells and therapeutic proteins; they form monolithic gels at body temperature. When injected in vivo the liquid formulations turn into gel implants in situ. This system was used successfully to deliver biologically active growth factors in vivo as well as an encapsulating matrix for living chondrocytes for tissue engineering applications. This study reports for the first time the use of polymer/polyol salt aqueous solutions as gelling systems, suggesting the discovery of a prototype for a new family of thermosetting gels highly compatible with biological compounds.
Lipid-based nanosystems enable intracellular delivery of drugs in the oral cavity for the treatment of local diseases. To rationally design such systems, suitable matrix compositions and particle ...properties need to be identified, and manufacturing technologies that allow reproducible production have to be applied. This is a prerequisite for the reliable and predictable performance of
biological studies. Here, we showed that solid lipid nanoparticles (SLN, palmitic acid) and nanostructured lipid carriers (NLC, palmitic acid and oleic acid in different ratios) with a size of 250 nm, a negative zeta potential, and a polydispersity index (PdI) of less than 0.3 can be reproducibly prepared by high-pressure homogenization using quality by design and a predictive model. SLN and NLC were colloidally stable after contact with physiological fluid and did not form agglomerates. The
studies clearly showed that besides particle size, surface charge and hydrophobicity, matrix composition had a significant effect. More specifically, the addition of the liquid lipid oleic acid increased the cellular uptake capacity without changing the underlying uptake mechanism. Regardless of the matrix composition, caveolin-mediated endocytosis was the major route of uptake, which was confirmed by particle localization in the endoplasmic reticulum. Thus, this work provides useful insights into the optimal composition of lipid carrier systems to enhance the intracellular uptake capacity of drugs into the oral mucosa.
Amorphous calcium carbonate (ACC) and calcium phosphate (ACP) increasingly attract attention as initial solid phases in vertebrate and invertebrate hard tissue formation, as well as in materials ...science as a possible new synthetic route for advanced materials preparation. Although much is known about these two amorphous phases and similarities in the mechanisms of their formation are recognized, no attempt has been made to investigate their formation under defined and comparable initial experimental conditions, viz. supersaturation, the ratio of constituent ions, ionic strength and the presence of relevant inorganic additives. In this paper, the formation of ACC and ACP in three model precipitation systems of increased chemical complexity was investigated: (a) systems containing constituent ions, (b) systems containing additional co-ions, and (c) systems with higher ionic strength and addition of Mg 2+ . The results have shown that ACP is more stable and was formed at lower relative supersaturations in comparison to ACC. The precipitation domain of both phases expanded with increasing complexity of precipitation systems, with the ACP precipitation domains always being larger than those of ACC. In addition to stability, the presence of inorganic ions, especially Mg 2+ , influences the composition of both amorphous phases. The obtained results indicate that general similarity between ACC and ACP exists, but it could also be concluded that the similar chemical environment in which they form not necessarily leads to similar structural properties.
Fuzzy logic controls have been used to develop intelligent control systems in greenhouses, leading to promote a comfortable microclimate for plant growth while saving energy and water resources. ...Solar energy is an effective solution to extend the use of these intelligent systems in isolated areas. In fact, this paper presents a practical solution based on the power-aware design for controlling the indoor environment of solar greenhouses. The system consists of feedback fuzzy logic controllers that log key field parameters using specific sensors and performs control actions for the environmental temperature, soil moisture, and relative humidity. With regard to the battery-coupled architecture of the solar system, the decision level is designed to consider the availability of operational resources before acting. Keeping in mind the constraint of low-cost, we propose a flexible design of an embedded system able to support remote management of the indoor environment key-parameters. The proposed control system was validated experimentally. The efficiency of the system was assessed by demonstrating significant energy and water savings as well as protection of solar system components from dry running issues
This paper describes one practical approach that suggests a model based technique to control in real time the relative humidity under greenhouse. The humidity level is one of the most difficult ...environmental factors to be regulated in greenhouse. Moreover, maintaining and correcting for more or less humidity can be a challenge for even the most sophisticated monitoring and control equipment. For these raisons, a Linear Quadratic Gaussian (LQG) controller for relative humidity regulation under greenhouse turns out to be useful. Indeed a LQG controller is proposed for a relative humidity under a greenhouse control task. So, the state space model, which is best fitting the acquired data, was identified using the Numerical Subspace State Space System IDentification (N4SID) algorithm. The mathematical model that is obtained will be used for evaluating the parameters of LQG strategy. The proposed controller is implemented in two steps, in one hand, Kalman filter (KF) is used to develop an observer that estimates the state of relative humidity under greenhouse. In the other hand, the state feedback controller gain is estimated using a linear quadratic criterion function. The suggested optimal implemented controller using Matlab/Simulink environment is applied to an experimental greenhouse. We found, according to the results, that the controller is able to lead the inside relative humidity to the desired value with high accuracy, regardless of the external disturbances.
The influence of monomeric and micellar concentrations of the cationic monomeric, dodecyltrimethylammonium bromide (DTAB), and the corresponding dimeric, bis( N , N -dimethyl- N ...-dodecyl)ethylene-1,2-diammonium dibromide (12-2-12), surfactants on the formation and transformation of amorphous calcium phosphate (ACP) was investigated. The combination of microscopy (AFM and TEM) and light scattering techniques (size and zeta potential measurements) enabled, for the first time, the simultaneous monitoring of the effect that additives exert on different length scales during CaP formation in solution – from prenucleation clusters and ACP particles to the crystalline phase. Depending on their aggregation state (monomers or micelles) and the geometry of the aggregate (spherical or elongated micelles), DTAB and 12-2-12 have exhibited different effects on the rate of ACP transformation, as well as on the morphology of the amorphous and crystalline phases. It was shown that the effect of surfactants on the precipitation process observed on the microscale could be a result of different pathways on the nanoscale. The obtained results may have implications for the understanding of the general mechanism of inorganic–organic interactions underlying the biomineralization processes, as well as for materials science.
Lead-acid batteries have been the most widely used energy storage units in stand-alone photovoltaic (PV) applications. To make a full use of those batteries and to improve their lifecycle, high ...performance charger is often required. The implementation of an advanced charger needs accurate information on the batteries internal parameters. In this work, we selected CIEMAT model because of its good performance to deal with the widest range of lead acid batteries. The performance evaluation of this model is based on the co-simulation LabVIEW/Multisim. With the intention of determining the impact of the charging process on batteries, the behaviour of different internal parameters of the batteries was simulated. During the charging mode, the value of the current must decrease when the batteries’ state of charge is close to be fully charged.
In this work, a low-cost method of functionalization of zero-valent iron nanoparticles (nZVI) by dipicolinic acid (2,6-pyridinedicarboxylic acid, PDCA) through one-pot chemical synthesis was applied. ...The synthesized PDCA@nZVI nanomaterial was characterized
via
scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. Functionalization by PDCA produced core-shell nanoparticles with magnetite and feroxyhyte mixed oxide layers. Tuning of particle size and shape was achieved by using different molar ratios of starting reagents during synthesis. The formation of short-chains of larger spherical particles was observed after the use of an equimolar (1 : 1) ratio of PDCA to iron ions and aggregated smaller ellipsoidal particles were produced after the use of a 1 : 2 molar ratio. The applicability of differently shaped nanomaterials for trace Cd ion removal from aqueous solutions was tested using the ICP-OES method. The removal efficiency achieved when using 10 mg of the functionalized PDCA@nZVI nanomaterial was 100% at cadmium levels below 5 mg L
−1
. The removal capacities were 77.6 mg g
−1
for bare nZVI particles, 80.3 mg g
−1
for one-pot synthesized PDCA@nZVI 1/1, and 110.2 mg g
−1
for the one-pot synthesized PDCA@nZVI 1/2 material. Specific sorption properties of the PDCA@nZVI material in the presence of trace levels of Cd were observed through the measurement of hydrodynamic diameter and change of zeta-potential in solutions. The differences in sorption between spherical and ellipsoidal particles at low Cd concentrations are explained through the effects of intraparticle and surface diffusion steps. Comparison of removal efficiency after Cd sorption on bare nZVI particles, one-pot synthesized PDCA@nZVI particles, and the particles obtained by subsequent incubation revealed that adsorption was enhanced when using the one-pot synthesized nanomaterial.
Dipicolinic acid capped iron nanoparticles were obtained by a facile one-pot chemical synthesis and the ellipsoidal forms of PDCA@nZVI nanoparticles showed enhanced adsorption of cadmium ions at trace levels.
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