Copper complex molecules as dye-sensitizers: Hybrid MetaGGA and standard + van der Waals functionals.

This study focuses on the use of Density Functional Theory calculations with two main approaches: computational chemistry and computational physics. The following three cases were considered for the derivation: (I) computational chemistry using the M06 hybrid functional, (II) computational chemistry using the standard PBE functional including vdW interactions, and (III) computational physics using the standard PBE functional including vdW interactions and periodic boundary conditions. Since the approximation using hybrid functionals M06 has been extensively validated, this method was used as a reference. The second and third methods are less expensive, it is ideal for use to extend large systems. From the sensitized molecules are found in the gas phase and include solvent effects through the integral equation formalism polarizable continuum model. In a systematic analysis of 15 Cu complex molecules, a complete characterization for DSSCs has been carried out and molecular geometry, electronic and optical measurements have been reported.

Non-functional alternative splicing caused by a Latino pathogenic variant in a case of PMM2-CDG.

We report on a Mexican mestizo with a multisystemic syndrome including neurological involvement and a type I serum transferrin isoelectric focusing (Tf IEF) pattern. Diagnosis of PMM2-CDG was obtained by clinical exome sequencing (CES) that revealed compound heterozygous variants in PMM2, the encoding gene for the phosphomannomutase 2 (PMM2). This enzyme catalyzes the conversion of mannose-6-P to mannose-1-P required for the synthesis of GDP-Man and Dol-P-Man, donor substrates for glycosylation reactions. The identified variants were c.422G>A (R141H) and c.178G>T, the former being the most frequent PMM2 pathogenic mutation and the latter a previously uncharacterized variant restricted to the Latino population with conflicting interpretations of pathogenicity and that we here report causes leaky non-functional alternative splicing (p.V60Cfs*3).

Building on gAMBI in ports for a challenging biological invasions scenario: Blue-gNIS as a proof of concept.

The status of aquatic ecosystems has historically been monitored by the use of biotic indices. However, few biotic measures consider the presence of non-indigenous species as a sign of anthropogenic pollution and habitat disturbance even when this may seriously affect the metric scores and ecological status classifications of an environment. Today, biological invasions are currently one of the greatest threats to biodiversity and sustainable blue economies around the world. In this work, environmental assessments were conducted in the Port of Gijon, Northern Spain, using eDNA metabarcoding, and the gAMBI (genetics based AZTI Marine Biotic Index) was estimated. Results indicate a high/good ecological status within the port. However, nine non-indigenous species and five invasive species were found, and a modification of the gAMBI that includes species invasiveness was proposed: Blue-gNIS. The index was preliminary tested against existing validated indices such as gAMBI, BENTIX (based on the ecology of macroinvertebrates) and ALEX (based on the invasiveness of the species). Blue-gNIS classified the port in a good ecological status and showed its potential usefulness to achieve more complete water quality assessments of ports.

Dynamical heterogeneities and mechanical non-linearities: Modeling the onset of plasticity in polymer in the glass transition.

In this paper we focus on the role of dynamical heterogeneities on the non-linear response of polymers in the glass transition domain. We start from a simple coarse-grained model that assumes a random distribution of the initial local relaxation times and that quantitatively describes the linear viscoelasticity of a polymer in the glass transition regime. We extend this model to non-linear mechanics assuming a local Eyring stress dependence of the relaxation times. Implementing the model in a finite element mechanics code, we derive the mechanical properties and the local mechanical fields at the beginning of the non-linear regime. The model predicts a narrowing of distribution of relaxation times and the storage of a part of the mechanical energy --internal stress-- transferred to the material during stretching in this temperature range. We show that the stress field is not spatially correlated under and after loading and follows a Gaussian distribution. In addition the strain field exhibits shear bands, but the strain distribution is narrow. Hence, most of the mechanical quantities can be calculated analytically, in a very good approximation, with the simple assumption that the strain rate is constant.

Role of Dynamical Heterogeneities on the Mechanical Response of Confined Polymer.

Confinement induces various modifications in the dynamics of polymers as compared to bulk. We focus here on the role of dynamical heterogeneities on the mechanics of confined polymers. Using a simple model that allows computation of the mechanical response over 10 decades in frequency, we show that the local mechanical coupling controlling the macroscopic response in the bulk disappears in a confined geometry. The slowest domains significantly contribute to the mechanical response for increasing confinement. As a consequence, the apparent glass transition is broadened and shifted towards lower frequencies as confinement increases. We compare our numerical predictions with experiments performed on poly(ethylacrylate) chains in model filled elastomers. We suggest that the change of elastic coupling between domains induced by confinement should contribute significantly to the polymer mobility shift observed on filled systems.

Computer simulation of elastic constants of hydroxyapatite and fluorapatite.

Hydroxyapatite (HAP) and fluorapatite (FAP) are essential components of dental enamel and bone. In this paper, we report a computational study of the elastic properties of HAP and FAP using ab initio and force field techniques. We have obtained the HAP and FAP elastic stiffness constants in hexagonal symmetry by fitting the Hooke law for both the energy-strain and stress-strain relations. Our ab initio HAP stiffness constants differ from the results of previous calculations, but follow similar trends. The HAP and FAP stiffness constants calculated with the ab initio method are very similar, although FAP is slightly stiffer than HAP in the hexagonal plane, and more compliant along the hexagonal axis. The pseudo-single-crystal HAP experimental stiffness constants in current use are critically reviewed. Combining the data from the ab initio simulations with the experimental FAP stiffness constants, several alternative sets of HAP stiffness constants are proposed. The mismatch in properties between HAP and FAP is evidently too small to assume it to be directly responsible for dental enamel mechanical degradation with fluorosis disease.

Particles in model filled rubber: dispersion and mechanical properties.

We have been able to design model filled rubbers with exactly the same chemical structure but different filler arrangements. From these model systems, we show that the particle arrangement in the elastomeric matrix controls the strain softening at small strain amplitude known as the Payne effect, as well as the elastic modulus dependence on the temperature. More precisely, we observed that the Payne effect disappears and the elastic modulus only weakly depends on the temperature when the particles are well separated. On the contrary, samples with the same interfacial physical chemistry but with aggregated particles show large amplitudes of the Payne effect and their elastic modulus decreases significantly with the temperature. We discuss these effects in terms of glassy bridge formation between filler particles. The observed effects provide evidence that glassy bridges play a key role on the mechanical properties of filled rubbers.

Contribution of Candida albicans cell wall components to recognition by and escape from murine macrophages.

The pathogenicity of the opportunistic human fungal pathogen Candida albicans depends on its ability to escape destruction by the host immune system. Using mutant strains that are defective in cell surface glycosylation, cell wall protein synthesis, and yeast-hypha morphogenesis, we have investigated three important aspects of C. albicans innate immune interactions: phagocytosis by primary macrophages and macrophage cell lines, hyphal formation within macrophage phagosomes, and the ability to escape from and kill macrophages. We show that cell wall glycosylation is critically important for the recognition and ingestion of C. albicans by macrophages. Phagocytosis was significantly reduced for mutants deficient in phosphomannan biosynthesis (mmn4Delta, pmr1Delta, and mnt3 mnt5Delta), whereas O- and N-linked mannan defects (mnt1Delta mnt2Delta and mns1Delta) were associated with increased ingestion, compared to the parent wild-type strains and genetically complemented controls. In contrast, macrophage uptake of mutants deficient in cell wall proteins such as adhesins (ece1Delta, hwp1Delta, and als3Delta) and yeast-locked mutants (clb2Delta, hgc1Delta, cph1Delta, efg1Delta, and efg1Delta cph1Delta), was similar to that observed for wild-type C. albicans. Killing of macrophages was abrogated in hypha-deficient strains, significantly reduced in all glycosylation mutants, and comparable to wild type in cell wall protein mutants. The diminished ability of glycosylation mutants to kill macrophages was not a consequence of impaired hyphal formation within macrophage phagosomes. Therefore, cell wall composition and the ability to undergo yeast-hypha morphogenesis are critical determinants of the macrophage's ability to ingest and process C. albicans.

Los grupos extracurriculares en agronomía de la Universidad de Caldas (Colombia): 1970-2006: de la efervescencia política a la formación científica / Os grupos extracurriculares no programa de Agronomia da Universidade de Caldas (Colômbia): 1970-2006; da efervescência política ao treinamento científico / The extracurricular groups in Agricultural Engineering at the University of Caldas (Colombia): 1970-2006; from political effervescence to scientific training

En vista de que la formación de profesionales es un asunto complejo que supera los propósitos expresados en los planes de estudio, los estudiantes han complementado su formación mediante Grupos Extracurriculares (GE). Con el fin de dar cuenta de esta dinámica, se realizó una caracterización de éstos grupos en el programa de Agronomía de la Universidad de Caldas, desde el año 1970 hasta el 2006. Se trató de indagar cómo contribuyeron a la formación de los estudiantes y a la realimentación de los planes de estudio. El texto, en la primera parte analiza los GE como "comunidades de aprendizaje", en segundo lugar, se elabora una caracterización de los grupos en el programa Agronomía, en tres períodos: la efervescencia política de los años 70, el reflujo de los 80 y la emergencia de los semilleros de investigación, después de los 90. Por último, se presentan las lecciones aprendidas en este ejercicio de investigación, en donde se destaca y reafirma la importancia que tiene la formación en investigación.

Visto que o treinamento de profissionais é um assunto complexo que supera os propósitos expressados nos programas de estudos, os estudantes complementam seu treinamento mediante Grupos Extracurriculares (GE). Para dar conta desta dinâmica, fez-se uma caracterização destes grupos no programa de Agronomia da Universidade de Caldas, desde o ano 1976 até o ano 2006. Tratou-se de indagar como estes grupos contribuíram ao treinamento dos estudantes e à re-alimentação dos programas de estudos. Este texto analisa, na primeira parte, os GEs como "comunidades de aprendizagem"; em segundo lugar, faz-se uma caracterização dos grupos no programa de Agronomia em três períodos: na efervescência política dos anos 70, o refluxo dos anos 80 e a emergência dos viveiros de pesquisa depois dos anos 90. Por último, apresentam-se as lições apreendidas neste exercício, onde se destaca e reafirma a importância do treinamento em pesquisa.

Taking into consideration that training professionals is a complex matter that overcomes the goals consigned in the syllabus, the students have complemented their training by means of Extracurricular Groups (EG). To comply with this dynamics, a characterization of these groups in the program of Agricultural Engineering at the University of Caldas from 1970 to 2006 was carried out. It aimed at finding out how these groups contributed to the students' training and how they provided the syllabi with positive feedback. The first part of this paper examines the EG's as "learning communities"; the second part, characterizes the groups in the program of Agricultural Engineering in three periods: the political effervescence in the1970's, the reflux of the 80's and the emergence of research seedbeds after the 90's. Finally, some lessons that had been learned during this research exercise and that highlight and reaffirm the importance of research training are presented.

Radiofrequency thermocoagulation of lung tumours. Where we are, where we are headed.

Only 25% of all lung cancers are diagnosed in an early stage allowing surgical treatment. Primary tumours usually concerning lung metastasis are breast, colon, kidney, uterus/cervix, prostate, and head and neck tumours. During recent years many publications have confirmed the effectiveness and reliability of lung radiofrequency ablation (RFA) alone or together with other techniques (chemotherapy, radiotherapy...). Results suggest that survival increase and curative rates of lung radiofrequency are similar to those achieved by more aggressive procedures and present lower rates of complications. Pneumothorax, pleural effusion and alveolar haemorrhage are the most frequent complications. Indications for lung RFA must be individually evaluated by lung cancer committees. Percutaneous lung RFA may be useful in patients with pulmonary primary tumours and metastases, especially in those with nodules smaller than 3 cm and a peripheral location (>1 cm from the hilum). PET/CT seems to be the most accurate technique in patient follow up.

Radiofrequency thermocoagulation of lung tumours. Where we are, where we are headed

Only 25% of all lung cancers are diagnosed in an early stage allowing surgical treatment. Primary tumours usually concerning lung metastasis are breast, colon, kidney, uterus/cervix, prostate, and head and neck tumours. During recent years many publications have confirmed the effectiveness and reliability of lung radiofrequency ablation (RFA) alone or together with other techniques (chemotherapy, radiotherapy...). Results suggest that survival increase and curative rates of lung radiofrequency are similar to those achieved by more aggressive procedures and present lower rates of complications. Pneumothorax, pleural effusion and alveolar haemorrhage are the most frequent complications. Indications for lung RFA must be individually evaluated by lung cancer committees. Percutaneous lung RFA may be useful in patients with pulmonary primary tumours and metastases, especially in those with nodules smaller than 3 cm and a peripheral location (>1 cm from the hilum). PET/CT seems to be the most accurate technique in patient follow up (AU)

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Mechanisms of neutrophil death in human immunodeficiency virus-infected patients: role of reactive oxygen species, caspases and map kinase pathways.

Neutrophils from human immunodeficiency virus-positive (HIV+) patients have an increased susceptibility to undergo programmed cell death (PCD), which could explain neutropenia during advanced disease. In this work, key steps of PCD have been evaluated in neutrophils from HIV+ patients. The role of caspase-3, caspase-8, mitogen activated protein kinase (MAPK) and reactive oxygen species (ROS) was analysed. Spontaneous neutrophil death is dependent upon caspase-3 but independent of caspase-8, suggesting that the intrinsic pathway is involved as a pathogenic mechanism of PCD. Inhibition of ROS decreased spontaneous PCD and caspase-3 hydrolysis, connecting oxidative stress and caspase-3 activation with neutrophil PCD in HIV-infected patients. Additionally, an increased neutrophil death was observed in HIV+ patients, following inhibition of p38 MAPK, suggesting a role for p38 MAPK in cell survival during the disease. We conclude that oxidative stress secondary to HIV infection can accelerate neutrophil death.

Profiles of NK, NKT cell activation and cytokine production following vaccination against hepatitis B.

Human natural killer (NK) cells (CD56+ CD3-) represent crucial components of the innate immune system especially against viral infections and because their activation can modulate the outcome of the adaptive immune response. NKT cells (CD56+CD3+), a lymphocyte T population characterized by expression of surface markers of NK cells, are known to be abundant in the liver and their activation could be associated with hepatic injury. Using three-color flow cytometry to measure surface receptors and intracellular cytokines, we have explored early activation signals and cytokine production in NK and NKT cells within a group of hepatitis B vaccinated and non-vaccinated individuals. A specific increase of the CD56bright cell population, the activation receptor CD69 and IFN-gamma, was observed in NK cells following incubation with recombinant HBsAg in responders to vaccination. Comparable results were observed in NKT cells showing an increment of CD69, CD25, IL-2 and IFN-gamma expression in responder subjects. These parameters were statistically diminished in non-responder individuals (p<0.05) in both groups of cells. These results demonstrate a diminished activation of these cells in non-responders to the vaccine, suggesting that NK and NKT cells play an important role in the immune response following hepatitis B vaccination.

Modelling of geochemical reactions and experimental cation exchange in MX 80 bentonite.

Bentonites are widely used for waste repository systems because of their hydrodynamic, surface and chemical-retention properties. MX 80 bentonite (bentonite of Wyoming) contains approximately 85% Na/Ca-montmorillonite and 15% accessory minerals. The dominant presence of Na/Ca-montmorillonite in this clay mineral could cause it to perform exceptionally well as an engineered barrier for a radioactive waste repository because this buffer material is expected to fill up by swelling the void between canisters containing waste and the surrounding ground. However, the Na/Ca-montmorillonite could be transformed to other clay minerals as a function of time under repository conditions. Previous modelling studies based on the hydrolysis reactions have shown that the Na/Ca-montmorillonite-to-Ca-montmorillonite conversion is the most significant chemical transformation. In fact, this chemical process appears to be a simple cation exchange into the engineered barrier. The purpose of the present study was two-fold. Firstly, it was hoped to predict the newly formed products of bentonite-fluid reactions under repository conditions by applying a thermokinetic hydrochemical code (KIRMAT: Kinetic Reactions and Mass Transport). The system modelled herein was considered to consist of a 1-m thick zone of water-saturated engineered barrier. This non-equilibrated system was placed in contact with a geological fluid on one side, which was then allowed to diffuse into the barrier, while the other side was kept in contact with iron-charged water. Reducing initial conditions ( [P(O)2 approximately equals 0] ; Eh=-200 mV) and a constant reaction temperature (100 degrees C) were considered. Secondly, it was hoped to estimate the influence of inter-layer cations (Ca and Na) on the swelling behaviour of the MX 80 bentonite by using an isothermal system of water vapour adsorption and an environmental scanning electron microscope (ESEM) coupled with a digital image analysis (DIA) program. Here, the MX 80 bentonite was previously treated with concentrated solutions (1N) of calcium and sodium chlorides. The results confirmed that the Na/Ca-montmorillonite-to-Ca-montmorillonite conversion was the main chemical transformation in the bentonite barrier under repository conditions. A simplified method (based on volume balance) has shown that the swelling capacity of the engineered barrier would be slightly affected after 1000 years of diffusion-reaction because the volume of neo-formed swelling clays is almost directly proportional to the volume of transformed initial-montmorillonite. Minimal neo-formation of saponites, vermiculites and chlorites was also observed. In addition, an isothermal system of water adsorption and ESEM-DIA methods showed that in the raw-bentonite-to-Ca-bentonite exchange there is a small decrease in the amount of adsorbed water and the swelling potential.

Swelling-shrinkage measurements of bentonite using coupled environmental scanning electron microscopy and digital image analysis.

The swelling clays have been proposed as engineered barriers in geological disposal systems for waste because these materials are assumed to build a better impermeable zone around wastes by swelling. However, the swelling potential of soils is also considered a prevalent cause of damage to buildings and constructions. For these reasons, it is fundamental to investigate the physicochemical and mechanical behavior of swelling clays. In the current study, the swelling-shrinkage potential (aggregates scale) was estimated using an environmental scanning electron microscope (ESEM) coupled with a digital image analysis (DIA) program (Visilog). In fact, the isolated aggregates of raw and cation-exchanged bentonite were directly observed at different relative humidities in an ESEM chamber. Then the "Visilog" software was used to estimate the percent augmentation of the aggregate surface as a function of time and as a function of relative humidity. This estimation allows for the calculation of the swelling-shrinkage potential (%) of bentonite. Finally, a kinetic model of first order was tested to fit the kinetic experimental data of swelling-shrinkage potential. The results show that ESEM-DIA coupling can be a powerful method of estimating the swelling-shrinkage potential of expansive clays. In addition, the exponential models fit well with the kinetic experimental data.

Increased Fas-mediated apoptosis in polymorphonuclear cells from HIV-infected patients.

Neutrophils represent an important line of innate host defence against invading microorganisms and their functional detriment during HIV infection, including accelerated spontaneous cell death, has been shown to contribute to AIDS development. Neutrophils are susceptible to apoptosis via Fas and an interaction between Fas and FasL was suggested originally as a mechanism to explain constitutive neutrophil apoptosis. We have explored some intracellular pathways leading to PMN apoptosis from 28 HIV-infected patients and 24 healthy volunteers. As previously reported, accelerated spontaneous apoptosis was observed in HIV+ patients, but this did not correlate with viral load. Furthermore, an increase in the level of spontaneous apoptosis was detected in neutrophils from HIV-infected patients following inhibition of ERK, suggesting an impairment of this kinase pathway during the early stages of infection which may contribute to PMN dysfunction. An elevated susceptibility to undergo apoptosis was observed following cross-linking of Fas, which correlated both with viral load and co-expression of Fas/FasL surface molecules. Different mechanisms for spontaneous and Fas-induced apoptosis are proposed which together contribute to the neutropenia and secondary infections observed during the progression to AIDS.

Budd-Chiari syndrome caused by membranous obstruction of the inferior vena cava associated with coeliac disease.

Ten cases of Budd-Chiari syndrome associated with coeliac disease have been reported in the literature, most of them in North African subjects. Supporting this association, we report a new case in a young Spanish Caucasian man in whom the cause of the syndrome was the membranous obstruction of the inferior vena cava, an infrequent cause of Budd-Chiari syndrome in Western countries. A percutaneous balloon angioplasty was performed, with satisfactory outcome.

Ambulatorio didatico homeopatico: relato de experiencia / Didactal homeopathic ambulatory: experience report

Atraves do relato do acompanhamento de pacientes durante 4 mses no ambulatorio didatico da segunda turma de mestrado profissionalizante em homeopatia...