La Transformacion de una Economia: Observaciones de un Viaje a Mexico

This paper describes macroeconomic management and commercial policy reforms in Mexico during the 1980s and 1990s and reports the observations of a group of Costa Rican authorities and prominent businessmen who traveled to Mexico in June, 1991 in order to observe the implementation of these policy reforms. Interviews with government officials, private sector representatives and labor leaders are described. The government has been able to formulate a very effective and coherent strategy, based on rapid integration to the world economy and a change in the role of the state in the economy

Interferometric inverse synthetic aperture radar experiment using an interferometric linear frequency modulated continuous wave millimetre-wave radar

D. Felguera-Martín,1 J.-T. González-Partida,1 P. Almorox-González,1 M. Burgos-García,1 and B.-P. Dorta-Naranjo2 1Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Grupo de Microondas y Radar. Departamento de Señales, Sistemas y Radiocomunicaciones, Madrid, Spain 2Universidad de Las Palmas de Gran Canaria, Departamento de Señales y Comunicaciones, Las Palmas de Gran Canaria, Spain An interferometric linear frequency modulated continuous wave (LFMCW) millimetre-wave radar is presented, along with the results of an experiment conducted to study the feasibility of using it in a future millimetre-wave interferometric inverse synthetic aperture radar (InISAR) system. First, a description of the radar is given. Then, the signal processing chain is described, with special attention to the phase unwrapping technique. The interferometric phase is obtained by unwrapping the prominent target's phase in each antenna using a sliding frame processing technique. Cell migration issues in this method are also addressed. Simulations were carried out to illustrate and assess the processing chain and to show the effects of multipath echoes on the height measurement. In the real experiment, the range, speed and height of a moving target were tracked over consecutive inverse synthetic aperture radar (ISAR) image frames, verifying the performance of the whole system

β-N-acetylglucosaminidase grafted on mesoporous silica nanoparticles. A bionanoantibiotic system against Staphylococcus aureus bacteria

A bionanoantibiotic system based on beta-N-acetylglucosaminidase (Ami) and Lysozyme (Lyz) enzymes grafted on the external surface of amino functionalized mesoporous silica nanoparticles, having a radial arrangement of pores (MSNr-NH2), was prepared and fully characterized. Before the enzyme grafting the nanoparticles were also loaded with the antibiotic drug levofloxacin (Levo) to explore the possible synergic effect with the enzymes. MSNr-NH2-Lyz-Levo and MSNr-NH2-Ami-Levo did not show any activity against S. aureus. On the contrary, in the absence of the antibiotic, both Lyz and Ami immobilized on MSNr were able to destroy S. aureus cells, suggesting an inhibiting action of the antibiotic on the enzymes. Although the loading of immobilized Lyz was higher than that of Ami (76 vs. 20 mg/g, respectively), the highest antibacterial efficacy was found for MSNr-NH2-Ami nanoantibiotic. Moreover, MSNr-NH2-Ami was active against S. aureus even at very low concentration (12.5 mu g/ mL) with a bactericidal activity (79%), higher than that determined for MSNr-NH2 loaded with levofloxacin (54%). These results suggest the possibility of using enzyme grafted MSNr as a bionanoantibiotic drug with high efficiency even at low nanoparticles concentration

Effects of proanthocyanidin-functionalized hydroxyapatite nanoparticles on dentin bonding

Objectives To evaluate the effect of proanthocyanidin-functionalized hydroxyapatite nanoparticles (nHAp_PA) used as pretreatment at different concentrations on the microtensile bond strength (mu TBS) and endogenous enzymatic activity (MMPs) on pH-cycled dentin after 24 h and 6 months of artificial aging. Materials and methods Fifty human sound dentin blocks were randomly assigned to 5 groups (n = 10): (i) negative control (no treatment); (ii) positive control (pH-cycling); (iii) pH-cycling + 2% nHAp_PA for 60s; (iv) pH-cycling + 6.5% nHAp_PA for 60s; (v) pH-cycling + 15% nHAp_PA for 60s. A self-etch adhesive was used for bonding procedures before resin composite build-ups. Specimens were tested with the mu TBS test after 24 h and 6 months of laboratory storage. The proteolytic activity in each group was evaluated with gelatin zymography and in situ zymography. Data were statistically analyzed (p < 0.05). Results At 24 h, the TBS of the experimental groups were significantly higher than the controls (p <= 0.001), and no differences were observed between different concentrations (p > 0.05). Artificial aging significantly decreased bond strength in all groups (p <= 0.008); however, nHAp_PA 2% still yielded higher bonding values than controls (p <= 0.007). The groups pretreated with nHAp_PA exhibited lower MMP-9 and MMP-2 activities compared to the positive control group and almost the same enzymatic activity as the negative control group. In situ zymography showed that after 6 months of aging, nHAp_PA 2% and nHAp_PA 6,5% decreased enzymatic activity as well as the negative control. Conclusions Dentin pretreatment with nHAp_PA increased the bonding performance of a self-etch adhesive and decreased MMP-2 and MMP-9 activities after 6 months

Nanostructured Channel for Improving Emission Efficiency of Hybrid Light-Emitting Field-Effect Transistors

We report on the mechanism of enhancing the luminance and external quantum efficiency (EQE) by developing nanostructured channels in hybrid (organic/inorganic) light-emitting transistors (HLETs) that combine a solution-processed oxide and a polymer heterostructure. The heterostructure comprised two parts: (i) the zinc tin oxide/zinc oxide (ZTO/ZnO), with and without ZnO nanowires (NWs) grown on the top of the ZTO/ZnO stack, as the charge transport layer and (ii) a polymer Super Yellow (SY, also known as PDY-132) layer as the light-emitting layer. Device characterization shows that using NWs significantly improves luminance and EQE (≈1.1% @ 5000 cd m–2) compared to previously reported similar HLET devices that show EQE < 1%. The size and shape of the NWs were controlled through solution concentration and growth time, which also render NWs to have higher crystallinity. Notably, the size of the NWs was found to provide higher escape efficiency for emitted photons while offering lower contact resistance for charge injection, which resulted in the improved optical performance of HLETs. These results represent a significant step forward in enabling efficient and all-solution-processed HLET technology for lighting and display applications

Synthetic populations of protoplanetary disks. Impact of magnetic fields and radiative transfer

Protostellar disks are the product of angular momentum conservation during protostellar collapse. Understanding their formation is crucial because they are the birthplace of planets and their formation is also tightly related to star formation. Unfortunately, the initial properties of Class 0 disks and their evolution are still poorly constrained both theoretically and observationally. Aims: We aim to better understand the mechanisms that set the statistics of disk properties as well as to study their formation in massive protostellar clumps. We also want to provide the community with synthetic disk populations to better interpret young disk observations. Methods: We used the ramses code to model star and disk formation in massive protostellar clumps with magnetohydrodynamics, including the effect of ambipolar diffusion and radiative transfer as well as stellar radiative feedback. Those simulations, resolved up to the astronomical unit scale, have allowed us to investigate the formation of disk populations. Results: Magnetic fields play a crucial role in disk formation. A weaker initial field leads to larger and massive disks and weakens the stellar radiative feedback by increasing fragmentation. We find that ambipolar diffusion impacts disk and star formation and leads to very different disk magnetic properties. The stellar radiative feedback also have a strong influence, increasing the temperature and reducing fragmentation. Comparing our disk populations with observations reveals that our models with a mass-to-flux ratio of 10 seems to better reproduce observed disk sizes. This also sheds light on a tension between models and observations for the disk masses. Conclusions: The clump properties and physical modeling significantly impact disk populations. It is critical to for the tension, with respect to disk mass estimates, between observations and models to be solved with synthetic observations. This is particularly important in the context of understanding planet formation

Brain tissue recovery in obstructive congenital hydrocephalus after intraventricular transplantation of mesenchymal stem cells

Introduction: Bone marrow-derived mesenchymal stem cells (BM-MSC) are a potential therapeutic tool due to their ability for migrating and producing neuroprotector factors when transplanted. The aim of this study was to evaluate the short-time effects of a BM-MSC experimental therapy in the hyh mouse model with severe obstructive hydrocephalus. Methods: BM-MSC were characterized in vitro and then injected into the ventricles of hyh mice. Wild-type and saline-injected hyh mice were used as controls. Samples were studied by analyzing and comparing mRNA, protein and metabolites level expression in control and damaged tissue. Results: Undifferentiated BM-MSC were found to: i) spread into the periventricular astrocyte reaction region after four days post-injection, and, ii) be producing neuroprotector factors (GDNF and VEGF). Astrocytes located in periventricular edematous region increased their aquaporin-4 expression, as well as Slit2 expression (neuroprotective and anti-inflammatory molecule). There was also a significant reduction of osmolytes such as taurine and neuroexcytotoxic glutamate. Halved apoptotic cell death was detected in the periventricular walls. Conclusions: BM-MSC lead to recovery of the severe neurodegenerative conditions associated to congenital hydrocephalus mediated by reactive astrocytes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Supported by Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech, and PI15/0619 (ISCIII/FEDER)