59 research outputs found
Pioglitazone-Loaded PLGA Nanoparticles: Towards the Most Reliable Synthesis Method
Recent findings have proved the benefits of Pioglitazone (PGZ) against atherosclerosis and type 2 diabetes. Since the systematic and controllable release of this drug is of significant importance, encapsulation of this drug in nanoparticles (NPs) can minimize uncontrolled issues. In this context, drug delivery approaches based on several poly(lactic-co-glycolic acid) (PLGA) nanoparticles have been rising in popularity due to their promising capabilities. However, a fully reliable and reproducible synthetic methodology is still lacking. In this work, we present a rational optimization of the most critical formulation parameters for the production of PGZ-loaded PLGA NPs by the single emulsification-solvent evaporation or nanoprecipitation methods. We examined the influence of several variables (e.g., component concentrations, phases ratio, injection flux rate) on the synthesis of the PGZ-NPs. In addition, a comparison of these synthetic methodologies in terms of nanoparticle size, polydispersity index (PDI), zeta potential (ζp), drug loading (DL%), entrapment efficiency (EE%), and stability is offered. According to the higher entrapment efficiency content, enhanced storage time and suitable particle size, the nanoprecipitation approach appears to be the simplest, most rapid and most reliable synthetic pathway for these drug nanocarriers, and we demonstrated a very slow drug release in PBS for the best formulation obtained by this synthesis.Recent findings have proved the benefits of Pioglitazone (PGZ) against atherosclerosis and type 2 diabetes. Since the systematic and controllable release of this drug is of significant importance, encapsulation of this drug in nanoparticles (NPs) can minimize uncontrolled issues. In this context, drug delivery approaches based on several poly(lactic-co-glycolic acid) (PLGA) nanoparticles have been rising in popularity due to their promising capabilities. However, a fully reliable and reproducible synthetic methodology is still lacking. In this work, we present a rational optimization of the most critical formulation parameters for the production of PGZ-loaded PLGA NPs by the single emulsification-solvent evaporation or nanoprecipitation methods. We examined the influence of several variables (e.g., component concentrations, phases ratio, injection flux rate) on the synthesis of the PGZ-NPs. In addition, a comparison of these synthetic methodologies in terms of nanoparticle size, polydispersity index (PDI), zeta potential (ζp), drug loading (DL%), entrapment efficiency (EE%), and stability is offered. According to the higher entrapment efficiency content, enhanced storage time and suitable particle size, the nanoprecipitation approach appears to be the simplest, most rapid and most reliable synthetic pathway for these drug nanocarriers, and we demonstrated a very slow drug release in PBS for the best formulation obtained by this synthesis
CYTOCHROME P450 3A13 AND ENDOTHELIN JOINTLY MEDIATE DUCTUS ARTERIOSUS CONSTRICTION TO OXYGEN IN MICE
The fetal ductus arteriosus (DA) contracts to oxygen, and this feature, maturing through gestation, is considered important for its closure at birth. We have previously obtained evidence of the involvement of cytochrome P-450, possibly of the 3A subfamily (CYP3A), in oxygen sensing and have also identified endothelin (ET)-1 as the attendant effector for the contraction. Here, we examined comparatively wild-type (WT) and CYP3Anull (Cyp3a(-/-)) mice for direct validation of this concept. We found that the CYP3A subfamily is represented only by CYP3A13 in the WT DA. CYP3A13 was also detected in the DA by immunofluorescence microscopy, being primarily colocalized with the endoplasmic reticulum in both endothelial and muscle cells. However, a distinct signal was also evident in the plasma membrane. Isolated DAs from term WT animals developed a sustained contraction to oxygen with transient contractions superimposed. Conversely, no tonic response occurred in Cyp3a(-/-) DAs, whereas the phasic response persisted unabated. Oxygen did not contract the preterm WT DA but caused a full-fledged contraction after retinoic acid (RA) treatment. RA also promoted an oxygen contraction in the Cyp3a(-/-) DA. However, responses of RA-treated WT and Cyp3a(-/-) mice differed in that only the former abated with ET-1 suppression. This implies the existence of an alternative target for RA responsible for the oxygen-induced contraction in the absence of CYP3A13. In vivo, the DA was constricted in WT and Cyp3a(-/-) newborns, although with a tendency to be less narrowed in the mutant. We conclude that oxygen acts primarily through the complex CYP3A13 (sensor)/ET-1 (effector) and, in an accessory way, directly onto ET-1. However, even in the absence of CYP3A13, the DA may close postnatally thanks to the contribution of ET-1 and the likely involvement of compensating mechanism(s) identifiable with an alternative oxygen-sensing system and/or the withdrawal of relaxing influence(s) operating prenatally
Intersubband gain in a Bloch oscillator and Quantum cascade laser
The link between the inversion gain of quantum cascade structures and the
Bloch gain in periodic superlattices is presented. The proposed theoretical
model based on the density matrix formalism is able to treat the gain mechanism
of the Bloch oscillator and Quantum cascade laser on the same footing by taking
into account in-plane momentum relaxation. The model predicts a dispersive
contribution in addition to the (usual) population-inversion-dependent
intersubband gain in quantum cascade structures and - in the absence of
inversion - provides the quantum mechanical description for the dispersive gain
in superlattices. It corroborates the predictions of the semi-classical
miniband picture, according to which gain is predicted for photon energies
lower than the Bloch oscillation frequency, whereas net absorption is expected
at higher photon energies, as a description which is valid in the
high-temperature limit. A red-shift of the amplified emission with respect to
the resonant transition energy results from the dispersive gain contribution in
any intersubband transition, for which the population inversion is small.Comment: 10 pages, 6 figure
Self-consistent Overhauser model for the pair distribution function of an electron gas in dimensionalities D=3 and D=2
We present self-consistent calculations of the spin-averaged pair
distribution function for a homogeneous electron gas in the paramagnetic
state in both three and two dimensions, based on an extension of a model that
was originally proposed by A. W. Overhauser [Can. J. Phys. {\bf 73}, 683
(1995)] and further evaluated by P. Gori-Giorgi and J. P. Perdew [Phys. Rev. B
{\bf 64}, 155102 (2001)]. The model involves the solution of a two-electron
scattering problem via an effective Coulombic potential, that we determine
within a self-consistent Hartree approximation. We find numerical results for
that are in excellent agreement with Quantum Monte Carlo data at low and
intermediate coupling strength , extending up to in
dimensionality D=3. However, the Hartree approximation does not properly
account for the emergence of a first-neighbor peak at stronger coupling, such
as at in D=2, and has limited accuracy in regard to the spin-resolved
components and . We also
report calculations of the electron-electron s-wave scattering length, to test
an analytical expression proposed by Overhauser in D=3 and to present new
results in D=2 at moderate coupling strength. Finally, we indicate how this
approach can be extended to evaluate the pair distribution functions in
inhomogeneous electron systems and hence to obtain improved
exchange-correlation energy functionals.Comment: 14 pages, 7 figuers, to apear in Physical Review
Multimodality and ambient intelligence
In this report we discuss multimodal interface technology. We present examples of multimodal interfaces and show problems and opportunities. Fusion of modalities is discussed and some roadmap discussions on research in Multimodality are summarized. This report also discusses future developments where rather than communicating with a single computer, users communicate with their environment using multimodal interactions and where the environmental interface has perceptual competence that includes being able to interpret what is going on in the environment. We contribute roles to virtual humans in order to allow daily users of future computing environments to establish relationships with the environments, or more in particular, these virtual humans
Internet of Things in Sustainable Energy Systems
Our planet has abundant renewable and conventional energy resources but technological capability and capacity gaps coupled with water-energy needs limit the benefits of these resources to citizens. Through IoT technology solutions and state-of-the-art IoT sensing and communications approaches, the sustainable energy-related research and innovation can bring a revolution in this area. Moreover, by the leveraging current infrastructure, including renewable energy technologies, microgrids, and power-to-gas (P2G) hydrogen systems, the Internet of Things in sustainable energy systems can address challenges in energy security to the community, with a minimal trade-off to environment and culture. In this chapter, the IoT in sustainable energy systems approaches, methodologies, scenarios, and tools is presented with a detailed discussion of different sensing and communications techniques. This IoT approach in energy systems is envisioned to enhance the bidirectional interchange of network services in grid by using Internet of Things in grid that will result in enhanced system resilience, reliable data flow, and connectivity optimization. Moreover, the sustainable energy IoT research challenges and innovation opportunities are also discussed to address the complex energy needs of our community and promote a strong energy sector economy
Nutrition, growth and resilience of tiger grouper(Epinephelus fuscoguttatus) 3 giant Grouper (Epinephelus lanceolatus) hybrid- a review
The hybrid grouper discussed in this paper is a cross between female tiger grouper (Epinephelus fuscoguttatus) and male giant grouper (Epinephelus lanceolatus). Performed for the first time at this institute, the hybridization was motivated by the need to meet grouper demand. The hybrid has been a subject of thorough scientific investigations ever since it was produced. Qualities such as dietary needs, efficiency in growth and production and environmental resilience are of considerable aquaculture advantage, and account for interest in its commercialâscale farming in the wider AsiaâPacific region. This paper reviews scientific evidences on tolerance of hybrid grouper to environmental variability, nutrition, growth and genetic and other aspects. It makes serious attempt to summarize the pertinent data published on specific research questions to improve understanding of the diverse evidences, and to be able to identify gaps in knowledge. This has helped in articulating the current state of research and defining topics for future studies on the hybrid. From the analysis of published data it is obvious that hybrid has a higher production potential and resilience. Nevertheless, the hybrid is vulnerable to health problems linked to nutritional deficiencies and other factors. More comprehensive data on dietary requirements of the hybrid, especially larval stages, will help in formulating feeds that cater to metabolic requirements and improve the survival and biomass gains. Information on hybrid's dietary flexibility can be used in developing feeds for growâout stages comprising ingredients from sustainable sources. The hybrid could be a suitable candidate for adapting aquaculture to climate change
An improvement in ro-ro stern berthing modelled on a case study
The high volume transported by ro-ro vessels has not come without a price. Accidents and incidents related
to design â lack of bulkheads, instability, problems with cargo access doors, stowage, securing cargo and lifesaving
appliances â are growing along with the size of the vessels themselves. One particular and recurrent
problem is the degree of these giant box-like high riding vessels exposed to wind. Recently the effect of a tramontana
â a fierce, sudden and short term regional wind â in the Port of Koper was to detach a moored ship,
causing an accident. This paper will present a study of that accident, and through simulations and modelling
determine an improvement that will allow berthing perpendicular to the stern ramp to function more securely
Manifest voor de ontwikkelidentiteit: over het belang van schatgraven naar jouw manier van leren en ontwikkelen
Met dit manifest worden professionals, en met name zij die het leren van anderen begeleiden en organiseren, meenemen in het belang en de werking van ontwikkelidentiteit en een kleine opmaat geven in hoe hiermee te werken. Je ontwikkelidentiteit is dat wat je leren en ontwikkelen (vorm en inhoud) onvervreemdbaar kleur geeft op de verbinding van wie je bent en de context waarin je je bevindt. Wanneer iemand meer inzicht heeft in zijn ontwikkelidentiteit, kan hij beter sturing geven aan zijn leren en ontwikkelen. Je wordt meegenomen langs het ontstaan van ontwikkelidentiteit, hoe dit raakt aan allerlei bewegingen op team, organisatie en maatschappelijk niveau en hoe je je eigen ontwikkelidentiteit kan verkennen. Er wordt afgesloten met een aantal aandachtspunten en denkrichtingen voor wat ons staat te doen als we er meer recht aan willen doen. Bij dit manifest zijn ook dialoogkaarten, genaamd Ons Ontwikkelen Ontward (2022), ontwikkeld die helpen om je ontwikkelidentiteit onder de loep te nemen
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