Influence of process variables on the kinetic parameters of a Langmuir-Hinshelwood expression for E.coli inactivation during the photocatalytic disinfection of water

This research describes the effect of the photocatalyst concentration, irradiation power, concentration of inorganic salts and the initial pH on the three parameters of a Langmuir-Hinshelwood-model: inactivation kinetic constant; k, dimensionless interaction coefficient; K*, and inhibition coefficient; n, which was applied to the photocatalytic disinfection of water with TiO2. In general, there is a qualitative finding in the effects on parameters of some variables since an increase in k was always related to a decrease in K*. Such relation was observed for the amount of TiO2, the irradiation power and the increase in concentration of inorganic salts: NaCl and CaCO3. Moreover, increase in MgSO4 concentration do not cause a tendency of change on the described parameters. As for pH of the reaction media, an increasing effect on k is observed when its value promotes proximity between bacteria and TiO2 particles. Finally, small changes were observed for n with the studied variables, but indeed significant for mathematical fitting. Thus, these findings led to the formulation of a mathematical description of the effects of the most important variables and their interactions on the kinetic parameters. This last hypothesis was validated by comparison of experimental and predicted data with high correlations

Self-organized network evolution coupled to extremal dynamics

The interplay between topology and dynamics in complex networks is a fundamental but widely unexplored problem. Here, we study this phenomenon on a prototype model in which the network is shaped by a dynamical variable. We couple the dynamics of the Bak-Sneppen evolution model with the rules of the so-called fitness network model for establishing the topology of a network; each vertex is assigned a fitness, and the vertex with minimum fitness and its neighbours are updated in each iteration. At the same time, the links between the updated vertices and all other vertices are drawn anew with a fitness-dependent connection probability. We show analytically and numerically that the system self-organizes to a non-trivial state that differs from what is obtained when the two processes are decoupled. A power-law decay of dynamical and topological quantities above a threshold emerges spontaneously, as well as a feedback between different dynamical regimes and the underlying correlation and percolation properties of the network.Comment: Accepted version. Supplementary information at http://www.nature.com/nphys/journal/v3/n11/suppinfo/nphys729_S1.htm

Light scattering from disordered overlayers of metallic nanoparticles

We develop a theory for light scattering from a disordered layer of metal nanoparticles resting on a sample. Averaging over different disorder realizations is done by a coherent potential approximation. The calculational scheme takes into account effects of retardation, multipole excitations, and interactions with the sample. We apply the theory to a system similar to the one studied experimentally by Stuart and Hall [Phys. Rev. Lett. {\bf 80}, 5663 (1998)] who used a layered Si/SiO$_2$/Si sample. The calculated results agree rather well with the experimental ones. In particular we find conspicuous maxima in the scattering intensity at long wavelengths (much longer than those corresponding to plasmon resonances in the particles). We show that these maxima have their origin in interference phenomena in the layered sample.Comment: 19 pages, 12 figure

Proteasome Dysfunction Associated to Oxidative Stress and Proteotoxicity in Adipocytes Compromises Insulin Sensitivity in Human Obesity

AIMS: Obesity is characterized by a low-grade systemic inflammatory state and adipose tissue (AT) dysfunction, which predispose individuals to the development of insulin resistance (IR) and metabolic disease. However, a subset of obese individuals, referred to as metabolically healthy obese (MHO) individuals, are protected from obesity-associated metabolic abnormalities. Here, we aim at identifying molecular factors and pathways in adipocytes that are responsible for the progression from the insulin-sensitive to the insulin-resistant, metabolically unhealthy obese (MUHO) phenotype. RESULTS: Proteomic analysis of paired samples of adipocytes from subcutaneous (SC) and omental (OM) human AT revealed that both types of cells are altered in the MUHO state. Specifically, the glutathione redox cycle and other antioxidant defense systems as well as the protein-folding machinery were dysregulated and endoplasmic reticulum stress was increased in adipocytes from IR subjects. Moreover, proteasome activity was also compromised in adipocytes of MUHO individuals, which was associated with enhanced accumulation of oxidized and ubiquitinated proteins in these cells. Proteasome activity was also impaired in adipocytes of diet-induced obese mice and in 3T3-L1 adipocytes exposed to palmitate. In line with these data, proteasome inhibition significantly impaired insulin signaling in 3T3-L1 adipocytes. INNOVATION: This study provides the first evidence of the occurrence of protein homeostasis deregulation in adipocytes in human obesity, which, together with oxidative damage, interferes with insulin signaling in these cells. CONCLUSION: Our results suggest that proteasomal dysfunction and impaired proteostasis in adipocytes, resulting from protein oxidation and/or misfolding, constitute major pathogenic mechanisms in the development of IR in obesity.IMIBIC/Universidad de Córdoba-SCAI (ProteoRed, PRB2-ISCIII)MINECO/FEDERJunta de Andalucía/FEDERCIBERobn(Instituto de Salud Carlos III

Water jet erosion performance of carbon fiber and glass fiber reinforced polymers

Complex engineering challenges are revealed in the wind industry; one of them is erosion at the leading edge of wind turbine blades. Water jet erosive wear tests on carbon-fiber reinforced polymer (CFRP) and glass-fiber reinforced polymer (GFRP) were performed in order to determine their resistance at the conditions tested. Vacuum Infusion Process (VIP) was used to obtain the composite materials. Eight layers of bidirectional carbon fabric (0/90°) and nine glass layers of bidirectional glass cloth were used to manufacture the plates. A water injection platform was utilized. The liquid was projected with a pressure of 150 bar on the surface of the specimens through a nozzle. The samples were located at 65 mm from the nozzle at an impact angle of 75°, with an exposure time of 10, 20 and 30 min. SEM and optical microscopy were used to observe the damage on surfaces. A 3D optical profilometer helped to determine the roughness and see the scar profiles. The results showed that the volume loss for glass fiber and carbon fiber were 10 and 19 mm3, respectively. This means that the resistance to water jet erosion in uncoated glass fiber was approximately two times lower than uncoated carbon fiber

Surface plasmon polaritons on narrow-ridged short-pitch metal gratings

Ian R. Hooper and J. Roy Sambles, Physical Review B, Vol. 66, article 205408 (2002). "Copyright © 2002 by the American Physical Society."The reflectivity of short pitch metal gratings consisting of a series of narrow Gaussian ridges in the classical mount has been modeled as a function of frequency and in-plane wave vector (the plane of incidence containing the grating vector) for various ridge heights. Surface plasmon polaritons (SPP’s) are found to be excited even in the zero-order region of the spectrum. These may result in strong absorption of radiation polarized with its electric field in the plane of incidence (transverse magnetic). For zero in-plane wave vector the SPP modes consist of a symmetric charge distribution on either side of the grating ridges, a family of these modes existing with different numbers of field maxima per grating period. Because of the charge symmetry these modes may only be coupled to at angles away from normal incidence where strong resonant absorption may then occur. The dispersion of these SPP modes as a function of the in-plane wave vector is found to be complex arising from the formation of very large band gaps due to the harmonic content of the grating profile, the creation of a pseudo high-energy mode, and through strong interactions between different SPP bands

Continuous Supply of Plasmodium vivax Sporozoites from Colonized Anopheles darlingi in the Peruvian Amazon.

In vitro culture of Plasmodium vivax liver stages underlies key understandings of the fundamental biology of this parasite, particularly the latent, hyponozoite stage, toward drug and vaccine development. Here, we report systematic production of Plasmodium vivax sporozoites in colonized Anopheles darlingi mosquitoes in the Peruvian Amazon. Human subject-derived P. vivax-infected blood was fed to Anopheles darlingi females using standard membrane feedings assays. Optimizing A. darlingi infection and sporozoite production included replacement of infected patient donor serum with naïve donor serum, comparing anticoagulants in processing blood samples, and addition of penicillin-streptomycin and ATP to infectious blood meals. Replacement of donor serum by naïve serum in the P. vivax donor blood increased oocysts in the mosquito midgut, and heparin, as anticoagulant, was associated with the highest sporozoite yields. Maintaining blood-fed mosquitoes on penicillin-streptomycin in sugar significantly extended mosquito survival which enabled greater sporozoite yield. In this study, we have shown that a robust P. vivax sporozoite production is feasible in a malaria-endemic setting where infected subjects and a stable A. darlingi colony are brought together, with optimized laboratory conditions

High rate, fast timing Glass RPC for the high {\eta} CMS muon detectors

The HL-LHC phase is designed to increase by an order of magnitude the amount of data to be collected by the LHC experiments. To achieve this goal in a reasonable time scale the instantaneous luminosity would also increase by an order of magnitude up to $6.10^{34} cm^{-2} s^{-1}$ . The region of the forward muon spectrometer ($|{\eta}| > 1.6$) is not equipped with RPC stations. The increase of the expected particles rate up to $2 kHz/cm^{2}$ (including a safety factor 3) motivates the installation of RPC chambers to guarantee redundancy with the CSC chambers already present. The actual RPC technology of CMS cannot sustain the expected background level. The new technology that will be chosen should have a high rate capability and provides a good spatial and timing resolution. A new generation of Glass-RPC (GRPC) using low-resistivity (LR) glass is proposed to equip at least the two most far away of the four high ${\eta}$ muon stations of CMS. First the design of small size prototypes and studies of their performance in high-rate particles flux is presented. Then the proposed designs for large size chambers and their fast-timing electronic readout are examined and preliminary results are provided.Comment: 14 pages, 11 figures, Conference proceeding for the 2016 Resistive Plate Chambers and Related Detector

Pressure-support ventilation or T-piece spontaneous breathing trials for patients with chronic obstructive pulmonary disease : a randomized controlled trial

Background Little is known about the best strategy for weaning patients with chronic obstructive pulmonary disease (COPD) from mechanical ventilation. Spontaneous breathing trials (SBT) using a T-piece or pressure-support ventilation (PSV) have a central role in this process. Our aim was to compare T-piece and PSV SBTs according to the duration of mechanical ventilation (MV) in patients with COPD. Methods Patients with COPD who had at least 48 hours of invasive MV support were randomized to 30 minutes of T-piece or PSV at 10 cm H2O after being considered able to undergo a SBT. All patients were preemptively connected to non-invasive ventilation after extubation. Tracheostomized patients were excluded. The primary outcome was total invasive MV duration. Time to liberation from MV was assessed as secondary outcome. Results Between 2012 and 2016, 190 patients were randomized to T-piece (99) or PSV (91) groups. Extubation at first SBT was achieved in 78% of patients. The mean total MV duration was 10.82 ± 9.1 days for the T-piece group and 7.31 ± 4.9 days for the PSV group (p < 0.001); however, the pre-SBT duration also differed (7.35 ± 3.9 and 5.84 ± 3.3, respectively; p = 0.002). The time to liberation was 8.36 ± 11.04 days for the T-piece group and 4.06 ± 4.94 for the PSV group (univariate mean ratio = 2.06 [1.29±3.27], p = 0.003) for the subgroup of patients with difficult or prolonged weaning. The study group was independently associated with the time to liberation in this subgroup.Conclusions The SBT technique did not influence MV duration for patients with COPD. For the difficult/ prolonged weaning subgroup, the T-piece may be associated with a longer time to liberation, although this should be clarified by further studies