Study of the interference fringes-caustic region interaction in a topological Young's interferometer.

Herein, an analysis of the optical field emerging from a topological Young's interferometer is conducted. The interferometer consists of two 3D-slit shape curves and is studied by projecting it onto a trihedral reference system. From the projection, Airy, Pearcey, and cusped-type beams emerge. The optical field of these beams is organized around its caustic region. The interference between these types of beams presents interesting physical properties, which can be derived from the interaction between the interference fringes and the caustic regions. One property of the interaction is the irradiance flow, which induces a long-distance interaction between the caustic regions. Another property is the bending of the interference fringes toward the caustic regions, which acts as a sink. Due to the adiabatic features of the caustic regions, the interaction between the fringes-caustic and caustic irradiance is studied using a predator-prey model, which leads to a logistic-type differential equation with nonlinear harvesting. The stability analysis of this equation is in good agreement with the theoretical and experimental results.

Sustainable use of wastes as reactive material in permeable reactive barrier for remediation of acid mine drainage: Batch and continuous studies.

The aim of this work was to evaluate the feasibility of the use of different industrial and agricultural wastes as reactive materials in Permeable Reactive Barriers (PRB) for Acid Mine Drainage (AMD) remediation. Sugar foam (SF), paper mill sludge (PMS), drinking water sludge (DWS) and olive mill waste (OMW) were evaluated in terms of pH neutralization and metal removal from AMD. Laboratory batch tests and continuous pilot scale up-flow columns containing 82% of Volcanic Slag (VS), as porous fill material, and 18% w/w of one of the industrial and agricultural wastes previously indicated, were tested. From the batch tests it was observed that the reactive material presenting the best results were the SF and the PMS. The results obtained in all the PRB were accurately described by a pseudo-first order model, presenting coefficient of determination higher than 0.96 in all the cases. During the continuous operation of the PRB, the porosity and hydraulic retention time (HRT) of most of the up-flow columns strongly decreased due to chemical precipitation and biofilm growth. The SF presented a significant number of fine particles that were washed out by the liquid flow, generating an effluent with very high total suspended solid concentration. Despite SF was the material with the highest alkalinity potential, the reduction of the HRT limited its neutralization and metal removal capacity. PMS and DWS presented the best pollutant removal yields in the continuous operation of the PRB, ranging from 55 to 99% and 55-95% (except in the case of the Mn), respectively. These results allowed the metal removal from the AMD. Additionally, these wastes presented very good biological sulphate reduction. Based on these results, the use of PMS and DWS as reactive material in PRB would allow to simultaneously valorise the industrial waste, which is very interesting within the circular economy framework, and to remove metals from the AMD by means of a low-cost and environmentally sustainable procedure.

[Relevance of Surface-Exposed Lysine Residues Designed for Functionalization of Laccase].

Fungal laccases are oxidoreductases with low-specificity for substrates. The characterization of laccase's surface is a prerequisite used to obtain hybrid catalysts with new properties. Surface-exposed lysine residues are targets in immobilization reactions. In this work, LAC3-K0, an enzyme devoid of lysine, was used as a platform to detect potential surface-exposed sites suitable for replacement with a lysine residue. Seven sites were selected from a LAC3-K0 3-D model, and single lysine mutants (UNIKn, n = residue number) were obtained by site-directed mutagenesis. All mutants were expressed in Saccharomyces cerevisiae W303-1A and detected as functional secreted proteins by their ability to oxidize guaiacol or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) on agar plates. All variants were active at acidic pH but presented no activity at neutral pH, as expected. Likewise, variants were stable a temperature between 15-55°C, and were completely inactivated at 70°C. Oxidation assays revealed that the replacement of one or two surface residues with lysine greatly affected enzyme activity and substrate specificity. The catalytic; parameters (KM^(app) and kcat^(app)) determined with ABTS were found to be different among the variants; Vmax^(app) was 1.5-2 fold higher in UNIK269 and triple mutant, with a KM^(app) of 0.27 and 0.30, respectively; kcat^(app )was 30.25 in UNIK238 and 32.34 in the triple mutant. The role of hydrophobic patches detected on the surface of LAC3-K0 was determined to be a favorable factor to be considered in the interaction of hybrid materials. All variants with uniquely surface located lysine created in this work can be in demand for obtaining laccases with a certain substrate specificity in the design of hybrid materials.

Stability of focusing regions and its vortex-solitonic properties.

Focusing regions, also known as caustic regions, are the singular solutions to the amplitude function of optical fields. Focusing regions are generated by the envelope curve of a set of critical points, which can be of attractor or repulsor type. The nature of the critical point depends on the refractive index. An important property of the critical points is that they present charge-like features. When a focusing region is generated in media with a random refractive index, current-like effects appear, and the evolution of the focusing regions follows a diffusion behavior. The morphology of the focusing regions may generate vortices or "eternal solutions" of solitonic type in a nonlinear medium. Herein, the condition under which these effects occur is analyzed and experimentally corroborated.

Insecticide susceptibility status in Mexican populations of Stegomyia aegypti (= Aedes aegypti): a nationwide assessment.

In Mexico, mosquito vector-borne diseases are of public health concern as a result of their impact on human morbidity and mortality. The use of insecticides against adult mosquitoes is one of the most common ways of controlling mosquito population densities. However, the use of these compounds has resulted in the development of insecticide resistance. The aim of this study was to estimate susceptibility to six pyrethroids, two carbamates and two organophosphates in Mexican populations of Stegomyia aegypti (Linnaeus, 1762) (= Aedes aegypti) (Diptera: Culicidae) mosquitoes. Bottle insecticide susceptibility tests, with 1 h exposure, were performed on adult mosquitoes from 75 localities across 28 states. At 30 min of exposure, the proportion of fallen mosquitoes was recorded. After 60 min of exposure, mosquitoes were recovered in non-treated containers and mortality was determined at 24 h after the set-up of the experiment. In general, the carbamate insecticides represented the most effective group in terms of the proportion of mosquitoes fallen at 30 min (72-100%) and 24-h mortality (97-100%). High and widespread resistance to pyrethroids Types I and II and, to a lesser extent, to organophosphates was observed. Insecticide susceptibility among and within states was highly variable.

First report of Stegomyia aegypti (= Aedes aegypti) in Mexico City, Mexico.

Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) is a species of mosquito that is currently widespread in Mexico. Historically, the mosquito has been distributed across most tropical and subtropical areas lower than 1700 m a.s.l. Currently, populations that are found at higher altitudes in regions with cold and dry climates suggest that these conditions do not limit the colonization and population growth of S. aegypti. During a survey of mosquitoes in September 2015, larvae of S. aegypti mosquitoes were found in two different localities in Mexico City, which is located at about 2250 m a.s.l. Mexico City is the most populous city in Mexico and has inefficient drainage and water supply systems. These factors may result in the provision of numerous larval breeding sites. Mosquito monitoring and surveillance are now priorities for the city.

Two-Particle Interference of Electron Pairs on a Molecular Level.

We investigate the photodouble ionization of H_{2} molecules with 400 eV photons. We find that the emitted electrons do not show any sign of two-center interference fringes in their angular emission distributions if considered separately. In contrast, the quasiparticle consisting of both electrons (i.e., the "dielectron") does. The work highlights the fact that nonlocal effects are embedded everywhere in nature where many-particle processes are involved.

Electron localization following attosecond molecular photoionization.

For the past several decades, we have been able to directly probe the motion of atoms that is associated with chemical transformations and which occurs on the femtosecond (10(-15)-s) timescale. However, studying the inner workings of atoms and molecules on the electronic timescale has become possible only with the recent development of isolated attosecond (10(-18)-s) laser pulses. Such pulses have been used to investigate atomic photoexcitation and photoionization and electron dynamics in solids, and in molecules could help explore the prompt charge redistribution and localization that accompany photoexcitation processes. In recent work, the dissociative ionization of H(2) and D(2) was monitored on femtosecond timescales and controlled using few-cycle near-infrared laser pulses. Here we report a molecular attosecond pump-probe experiment based on that work: H(2) and D(2) are dissociatively ionized by a sequence comprising an isolated attosecond ultraviolet pulse and an intense few-cycle infrared pulse, and a localization of the electronic charge distribution within the molecule is measured that depends-with attosecond time resolution-on the delay between the pump and probe pulses. The localization occurs by means of two mechanisms, where the infrared laser influences the photoionization or the dissociation of the molecular ion. In the first case, charge localization arises from quantum mechanical interference involving autoionizing states and the laser-altered wavefunction of the departing electron. In the second case, charge localization arises owing to laser-driven population transfer between different electronic states of the molecular ion. These results establish attosecond pump-probe strategies as a powerful tool for investigating the complex molecular dynamics that result from the coupling between electronic and nuclear motions beyond the usual Born-Oppenheimer approximation.

Inline electron holography and VEELS for the measurement of strain in ternary and quaternary (In,Al,Ga)N alloyed thin films and its effect on bandgap energy.

We present the use of (1) dark-field inline electron holography for measuring the structural strain, and indirectly obtaining the composition, in a wurtzite, 4-nm-thick InAlGaN epilayer on a AlN/GaN/AlN/GaN multinano-layer heterosystem, and (2) valence electron energy-loss spectroscopy to study the bandgap value of five different, also hexagonal, 20-50-nm-thick InAlGaN layers. The measured strain values were almost identical to the ones obtained by other techniques for similarly grown materials. We found that the biaxial strain in the III-N alloys lowers the bandgap energy as compared to the value calculated with different known expressions and bowing parameters for unstrained layers. By contrast, calculated and experimental values agreed in the case of lattice-matched (almost unstrained) heterostructures.

Analysis of the stability of InGaN/GaN multiquantum wells against ion beam intermixing.

Ion-induced damage and intermixing was evaluated in InGaN/GaN multi-quantum wells (MQWs) using 35 keV N(+) implantation at room temperature. In situ ion channeling measurements show that damage builds up with a similar trend for In and Ga atoms, with a high threshold for amorphization. The extended defects induced during the implantation, basal and prismatic stacking faults, are uniformly distributed across the quantum well structure. Despite the extremely high fluences used (up to 4 × 10(16) cm(-2)), the InGaN MQWs exhibit a high stability against ion beam mixing.

Acrylamide and HMF occurrence and bioaccessibility in instant coffee and coffee substitutes. A study on isolated and milk-combined beverages.

This research evaluated the occurrence and bioaccessibility of acrylamide and HMF in commercial instant coffees (IC) and coffee substitutes (CS), considering both isolated consumption and combination with milk. There were no significant differences in acrylamide content between IC and CS samples (median: 589 vs. 671 µg/kg), but higher variability was reported for CS, probably due to their varied composition (roasted cereals, nuts, honey, dehydrated fruits, and/or chicory). Acrylamide level were always below the EU benchmark for each category. HMF contents were similar between both groups (1354-5127 mg/kg for IC and 735-7134 mg/kg for CS; median: 2890 vs. 2960 mg/kg), with no clear ingredient relationship. Since IC consumption by the Spanish population is ten times higher than that of CS, exposure to acrylamide and HMF was higher from IC (6.8 vs. 1.07 ng/kg body weight/day for acrylamide; 39.1 vs. 4.2 µg/kg body weight/day for HMF). The standardized in vitro gastrointestinal digestion protocol (INFOGEST) was used. The gastrointestinal process reduced the bioaccessibility of acrylamide up to 27.2 % in IC and to 22.4 % in CS, regardless of the presence of milk. HMF bioaccessibility from IC significantly dropped after the gastrointestinal digestion, whereas it greatly increased for CS. The presence of milk did not affect HMF bioaccessibility. These results highlight the importance of assessing food bioaccessibility in typical consumption scenarios, providing a holistic view and a realistic evaluation of the potential risks associated with acrylamide and HMF exposure in the diet.

Removal of phenolic inhibitors from lignocellulose hydrolysates using laccases for the production of fuels and chemicals.

Lignocellulose is the most abundant biopolymer in the biosphere. It is inexpensive and therefore considered an attractive feedstock to produce biofuels and other biochemicals. Thermochemical and/or enzymatic pretreatment is used to release fermentable monomeric sugars. However, a variety of inhibitory by-products such as weak acids, furans, and phenolics that inhibit cell growth and fermentation are also released. Phenolic compounds are among the most toxic components in lignocellulosic hydrolysates and slurries derived from lignin decomposition, affecting overall fermentation processes and production yields and productivity. Ligninolytic enzymes have been shown to lower inhibitor concentrations in these hydrolysates, thereby enhancing their fermentability into valuable products. Among them, laccases, which are capable of oxidizing lignin and a variety of phenolic compounds in an environmentally benign manner, have been used for biomass delignification and detoxification of lignocellulose hydrolysates with promising results. This review discusses the state of the art of different enzymatic approaches to hydrolysate detoxification. In particular, laccases are used in separate or in situ detoxification steps, namely in free enzyme processes or immobilized by cell surface display technology to improve the efficiency of the fermentative process and consequently the production of second-generation biofuels and bio-based chemicals.

Unveiling potential of promising filamentous microalga Klebsormidium cf. nitens: Shear stress resilience and carotenoid-fatty acid dynamics in tubular photobioreactor.

In this study, the effects of shear stress and different culture media on the growth of the filamentous microalga Klebsormidium cf. nitens were studied. The microalga's growth, carotenoids and fatty acids were further evaluated in a pump-driven tubular photobioreactor. The results show that this microalga had the ability to withstand high shear stress and the adaptability to grow in a culture medium that lacks certain trace elements. K. cf. nitens grew consistently in the tubular photobioreactor at different average light intensities although it did not grow well in a tall bubble column. The carotenoid analysis revealed that the xanthophyll cycle was activated to protect the cell photosynthetic system. The fatty acids increased with irradiance, with linoleic acid (C18:2n6) making up over 50 % of the total fatty acids. This study supports the potential of employing pump-driven tubular photobioreactors to produce the filamentous microalga K. cf nitens at the large scale.

Formation of intraneuronal iron deposits following local release from nanostructured silica injected into rat brain parenchyma.

Nanostructured materials with controllable properties have been used to cage and release various types of compounds. In the present study, iron-loaded nanostructured sol-gel SiO2-Fe materials were prepared and injected into the rat brain to develop a method for gradual iron delivery into the neurons with the aims to avoid acute iron toxicity and develop an animal model of gradual, metal-induced neurodegeneration. Nanoparticles were prepared by the traditional method of hydrolysis and condensation reactions of tetraethyl orthosilicate at room temperature and subsequent heat treatment at 200 °C. FeSO4 was added in situ during the silica preparation. The resulting materials were characterized by UV-VIS and infrared spectroscopies, X-ray diffraction, and N2 adsorption-desorption. An in vitro ferrous sulfate release test was carried out in artificial cerebrospinal fluid as the release medium showing successful ferrous sulfate loading on nanostructured silica and sustained iron release during the test time of 10 h. Male Wistar rats administered with SiO2-Fe nanoparticles in the substantia nigra pars compacta (SNpc) showed significant intraneuronal increase of iron, in contrast to the animals administered with FeSO4 that showed severe neuronal loss, 72 h post-treatment. Both treatments induced lipid fluorescent product formation in the ventral midbrain, in contrast to iron-free SiO2 and PBS-only injection controls. Circling behavior was evaluated six days after the intranigral microinjection, considered as a behavioral end-point of brain damage. The apomorphine-induced ipsilateral turns in the treated animals presented significant differences in relation to the control groups, with FeSO4 administration leading to a dramatic phenotype, compared to a milder impact in SiO2-Fe administrated animals. Thus, the use of SiO2-Fe nanoparticles represents a slow iron release system useful to model the gradual iron-accumulation process observed in the SNpc of patients with idiopathic Parkinson's disease.

KCNH1 potassium channels are expressed in cervical cytologies from pregnant patients and are regulated by progesterone.

Potassium voltage-gated channel, subfamily H (eag-related), member 1 (KCNH1) potassium channels are potential tumour markers and cancer therapeutic targets and are up-regulated by oestrogens and human papilloma virus (HPV) oncogenes. However, the role of KCNH1 in normal tissues is poorly understood, and its expression in pregnancy is unknown. We wondered whether KCNH1 channels are expressed in cervical cells from pregnant patients and whether progesterone (P4) regulates KCNH1. The association with HPV was also investigated. KCNH1 protein expression was studied by immunocytochemistry in liquid-based cervical cytologies; 93 samples were obtained from pregnant patients at different trimesters, and 15 samples were obtained from non-pregnant women (controls). The presence of HPV was studied by PCR with direct sequencing and nested multiplex PCR. HeLa cervical cancer cells were transfected with human progesterone receptor-B (PR-B) and treated with P4. KCNH1 mRNA expression in these cultures was studied by real-time PCR. KCNH1 protein was detected in 100% of the pregnancy samples and in 26% of the controls. We found 18 pregnant patients infected with HPV and detected 14 types of HPV. There was no association between the percentage of cells expressing KCNH1 and either the presence or type of HPV. P4 induced KCNH1 mRNA and protein expression in cells transfected with human PR-B. No regulation of KCNH1 by P4 was observed in non-transfected cells. We show for the first time the expression of an ion channel during human pregnancy at different trimesters and KCNH1 regulation by P4 in human cells. These data raise a new research field for KCNH1 channels in human tissues.

Selective ion-induced intermixing and damage in low-dimensional GaN/AlN quantum structures.

Ion-induced intermixing and damage is evaluated in GaN/AlN superlattices of quantum dots (QDs) and quantum wells (QWs) using 100 keV Ar(+) implantation at low temperature (15 K). Despite the similar damage build up at low fluences, a significant increase of the damage accumulation takes place for QDs at high fluences. Elemental depth profiles were fitted with a diffusion model, revealing the higher intermixing efficiency in QD superlattices, significantly higher than for QWs. The scaling of diffusion length with the local fluence and defect concentration is understood on the basis of cascade mixing and migration of defects in the cation sublattice. The selective intermixing/damage of QDs is explained by the promotion of lateral diffusion mechanisms that result in smooth interfaces, as well as by an enhanced diffusivity due to the characteristic strain distribution in QD superlattices.

A systems biology analysis of the Drosophila phagosome.

Phagocytes have a critical function in remodelling tissues during embryogenesis and thereafter are central effectors of immune defence. During phagocytosis, particles are internalized into 'phagosomes', organelles from which immune processes such as microbial destruction and antigen presentation are initiated. Certain pathogens have evolved mechanisms to evade the immune system and persist undetected within phagocytes, and it is therefore evident that a detailed knowledge of this process is essential to an understanding of many aspects of innate and adaptive immunity. However, despite the crucial role of phagosomes in immunity, their components and organization are not fully defined. Here we present a systems biology analysis of phagosomes isolated from cells derived from the genetically tractable model organism Drosophila melanogaster and address the complex dynamic interactions between proteins within this organelle and their involvement in particle engulfment. Proteomic analysis identified 617 proteins potentially associated with Drosophila phagosomes; these were organized by protein-protein interactions to generate the 'phagosome interactome', a detailed protein-protein interaction network of this subcellular compartment. These networks predicted both the architecture of the phagosome and putative biomodules. The contribution of each protein and complex to bacterial internalization was tested by RNA-mediated interference and identified known components of the phagocytic machinery. In addition, the prediction and validation of regulators of phagocytosis such as the 'exocyst', a macromolecular complex required for exocytosis but not previously implicated in phagocytosis, validates this strategy. In generating this 'systems-based model', we show the power of applying this approach to the study of complex cellular processes and organelles and expect that this detailed model of the phagosome will provide a new framework for studying host-pathogen interactions and innate immunity.

Acrylamide bioaccessibility in potato and veggie chips. Impact of in vitro colonic fermentation on the non-bioaccessible fraction.

Potato-based products contribute largely to the daily intake of acrylamide. In addition to potato crisps, the European Commission has included veggie crisps in the list of foods that should be monitored for their acrylamide content. In the present study, acrylamide content in potato and veggie chips (sweet potato, beetroot and carrot) and their bioaccessibility after in vitro digestion was assessed. The non-bioaccessible fraction was also submitted to in vitro fermentation under colonic conditions. Faecal samples from volunteers of three age groups (children, adolescents and adults) were used to evaluate the microbiota effect on the acrylamide availability. Sweet potato chips exhibited the highest acrylamide content (2342 µg/kg), followed by carrot (1279 µg/kg), beetroot (947 µg/kg) and potato chips (524 µg/kg). After in vitro digestion, acrylamide bioaccessibility was significantly lower in veggie chips (59.7-60.4 %) than in potato chips (71.7 %). Potato and sweet potato chips showed the significantly lowest acrylamide content in the non-bioaccessible fraction (22.8 and 24.1 %, respectively) as compared with beetroot chips (28.4 %). After the fermentation step, acrylamide percentage in the soluble fraction of veggie chips ranged from 43.03 to 71.89 %, the highest values being observed in sweet potato chips fermented with microbiota from children. This fact would involve that the acrylamide was released from the non-bioaccessible fractions by the microbiota. These findings point out that the levels of potentially absorbable acrylamide after the complete gastrointestinal process could be modulated by both the food matrix composition and the microbiota. These factors should be further considered for a more precise risk assessment of dietary acrylamide in humans.

[Clinical pathways in acute pancreatitis: recommendations for early multidisciplinary management. Scientific Committee of the SEMICYUC. Working Group on Infectious Diseases (GTEI-SEMICYUC)]. / Hoja de ruta de los cuidados clínicos para la pancreatitis aguda: recomendaciones para el manejo anticipado multidisciplinar (clinical pathways).

There is a growing body of evidence that early management of patients with acute pancreatitis may alter the natural course of disease and improve outcomes of patients. The aim of this paper is to optimize the management of patients with acute pancreatitis during the first 72 h after hospital admission by proposing several clinical care pathways. The proposed pathways are based on the SEMICYUC 2005 Recommendations with incorporation of the latest developments in the field, particularly the determinants-based classification of acute pancreatitis severity. The pathways also incorporate the "alarm signs", the use of therapeutic modalities known as PANCREAS, and the "call to ICU" criteria. Further studies will need to assess whether the adoption of these pathway reduces mortality and morbidity in patients with acute pancreatitis. The previous SEMICYUC guidelines on management of patients with acute pancreatitis in Intensive Care will need to be revised to reflect the recent developments in the field.