Study of non-covalent interactions on dendriplex formation: Influence of hydrophobic, electrostatic and hydrogen bonds interactions

The interaction of a double stranded small interference RNA (siRNA Nef) with cationic carbosilane dendrimers of generations 1-3 with two different ammonium functions at the periphery ([-NMe2R](+), R=Me, (CH2)(2)OH) has been studied by experimental techniques (zeta potential, electrophoresis, single molecule pulling experiments) and molecular dynamic calculations. These studies state the presence of different forces on dendriplex formation, depending on generation and type of ammonium group. Whilst for higher dendrimers electrostatic forces mainly drive the stability of dendriplexes, first generation compounds can penetrate into siRNA strands due to the establishment of hydrophobic interactions. Finally, in the particular case of first generation dendrimer [G(1)O(3)(NMe2(CH2)(2)OH))(6)](6+); the presence of hydroxyl groups reinforces dendriplex stability by hydrogen bonds formation. However, since these small dendrimers do not cover the RNA, only higher generation derivatives protect RNA from degradation.University of Alcalá; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN); Instituto de Investigación Sanitaria Gregorio Marañón; Universitat de Barcelon

Memetic Evolutionary Multi-Objective Neural Network Classifier to Predict Graft Survival in Liver Transplant Patients

In liver transplantation, matching donor and recipient is a problem that can be solved using machine learning techniques. In this paper we consider a liver transplant dataset obtained from eleven Spanish hospitals, including the patient survival or the rejection in liver transplantation one year after the surgery. To tackle this problem, we use a multi-objective evolutionary algorithm for training generalized radial basis functions neural networks. The obtained models provided medical experts with a mathematical value to predict survival rates allowing them to come up with a right decision according to the principles of justice, efficiency and equit

Influence of the AlN interlayer thickness on the photovoltaic properties of In-rich AlInN on Si heterojunctions deposited by RF sputtering

We report the influence of the AlN interlayer thickness (0-15 nm) on the photovoltaic properties of Al0.37In0.63N on Si heterojunction solar cells deposited by radio frequency sputtering. The poor junction band alignment and the presence of a 2-3 nm thick amorphous layer at the interface mitigates the response in devices fabricated by direct deposition of n-AlInN on p-Si(111). Adding a 4-nm-thick AlN buffer layer improves the AlInN crystalline quality and the interface alignment leading to devices with a conversion efficiency of 1.5% under 1-sun AM1.5G illumination. For thicker buffers the performance lessens due to inefficient tunnel transport through the AlN. These results demonstrate the feasibility of using In-rich AlInN alloys deposited by radio frequency sputtering as novel electron-selective contacts to Si-heterojunction solar cells

Pfeiffer syndrome. A case report

[ES]El síndrome de Pfeiffer (SP) es una enfermedad genética rara, descrita por Peiffer en 1964, que cursa con craneosinostosis, hipoplasia medio facial, sindactilia y pulgares gruesos con un amplio rango de severidad. Presentamos un caso, con revisión de la literatura. La obstrucción de la vía aérea superior en relación con la hipoplasia medio facial es una complicación frecuente en los casos graves, que debe valorarse y tratarse de manera precoz. [EN] Pfeiffer syndrome (PS) is a rare genetical disorder, originally described by Pfeiffer in 1964, and is characterized by craniosynostosis, regressed midface, syndactyly of hands and feet, and broad thumbs and big toes, with a wide range of variable severity. We report a case with a review of literature. Obstruction of the upper airway in relation to the midface hypoplasia is a frequent complication in severe cases to be assessed and treated early

Real-World Multicenter Experience of Immunosuppression Minimization Among 661 Liver Transplant Recipients.

BACKGROUND Long-term morbidity and mortality in liver transplant recipients is frequently secondary to immunosuppression toxicity. However, data are scarce regarding immunosuppression minimization in clinical practice. MATERIAL AND METHODS In this cross-sectional, multicenter study, we reviewed the indications of immunosuppression minimization (defined as tacrolimus levels below 5 ng/mL or cyclosporine levels below 50 ng/mL) among 661 liver transplant recipients, as well as associated factors and the effect on renal function. RESULTS Fifty-three percent of the patients received minimized immunosuppression. The median time from transplantation to minimization was 32 months. The most frequent indications were renal insufficiency (49%), cardiovascular risk (19%), de novo malignancy (8%), and cardiovascular disease (7%). The factors associated with minimization were older age at transplantation, longer post-transplant follow-up, pre-transplant diabetes mellitus and renal dysfunction, and the hospital where the patients were being followed. The patients who were minimized because of renal insufficiency had a significant improvement in renal function (decrease of the median serum creatinine level, from 1.50 to 1.34 mg/dL; P=0.004). Renal function significantly improved in patients minimized for other indications, too. In the long term, glomerular filtration rate significantly decreased in non-minimized patients and remained stable in minimized patients. CONCLUSIONS Immunosuppression minimization is frequently undertaken in long-term liver transplant recipients, mainly for renal insufficiency. Substantial variability exists regarding the use of IS minimization among centers

Polarity in GaN and ZnO: Theory, measurement, growth, and devices

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Rev. 3, 041303 (2016) and may be found at https://doi.org/10.1063/1.4963919.The polar nature of the wurtzite crystalline structure of GaN and ZnO results in the existence of a spontaneous electric polarization within these materials and their associated alloys (Ga,Al,In)N and (Zn,Mg,Cd)O. The polarity has also important consequences on the stability of the different crystallographic surfaces, and this becomes especially important when considering epitaxial growth. Furthermore, the internal polarization fields may adversely affect the properties of optoelectronic devices but is also used as a potential advantage for advanced electronic devices. In this article, polarity-related issues in GaN and ZnO are reviewed, going from theoretical considerations to electronic and optoelectronic devices, through thin film, and nanostructure growth. The necessary theoretical background is first introduced and the stability of the cation and anion polarity surfaces is discussed. For assessing the polarity, one has to make use of specific characterization methods, which are described in detail. Subsequently, the nucleation and growth mechanisms of thin films and nanostructures, including nanowires, are presented, reviewing the specific growth conditions that allow controlling the polarity of such objects. Eventually, the demonstrated and/or expected effects of polarity on the properties and performances of optoelectronic and electronic devices are reported. The present review is intended to yield an in-depth view of some of the hot topics related to polarity in GaN and ZnO, a fast growing subject over the last decade

Probing inhomogeneous composition in core/shell nanowires by Raman spectroscopy

Due to its non-destructive and its micro-spatial resolution, Raman spectroscopy is a powerful tool for a rapid structural and compositional characterization of nanoscale materials. Here, by combining the compositional dependence of the Raman peaks with the existence of photonic modes in the nanowires, we address the composition inhomogeneities of AlxGa1-xAs/GaAs core/shell structures. The experimental results are validated with complementary chemical composition maps of the nanowire cross-sections and finite-difference time-domain simulations of the photonic modes. (C) 2014 AIP Publishing LLC

Purcell Enhancement and Wavelength Shift of Emitted Light by CsPbI3 Perovskite Nanocrystals Coupled to Hyperbolic Metamaterials

Manipulation of the exciton emission rate in nanocrystals of lead halide perovskites (LHPs) was demonstrated by means of coupling of excitons with a hyperbolic metamaterial (HMM) consisting of alternating thin metal (Ag) and dielectric (LiF) layers. Such a coupling is found to induce an increase of the exciton radiative recombination rate by more than a factor of three due to the Purcell effect when the distance between the quantum emitter and HMM is nominally as small as 10 nm, which coincides well with the results of our theoretical analysis. Besides, an effect of the coupling-induced long wavelength shift of the exciton emission spectrum is detected and modeled. These results can be of interest for quantum information applications of single emitters on the basis of perovskite nanocrystals with high photon emission rates