An experimental and theoretical investigation of particle–wall impacts in a T-junction

Understanding the behaviour of particles entrained in a fluid flow upon changes in flow direction is crucial in problems where particle inertia is important, such as the erosion process in pipe bends.We present results on the impact of particles in a T-shaped channel in the laminar-turbulent transitional regime. The impacting event for a given system is described in terms of the Reynolds number and the particle Stokes number. Experimental results for the impact are compared with the trajectories predicted by theoretical particle tracing models for a range of configurations to determine the role of the viscous boundary layer in retarding the particles and reducing the rate of collision with the substrate. In particular a 2D model based on a stagnation point flow is used together with 3D numerical simulations. We show how the simple 2D model provides a tractable way of understanding the general collision behaviour, while more advanced 3D simulation can be helpful in understanding the details of the flow

Optimising DNA binding to carbon nanotubes by non-covalent methods

The use of carbon nanotubes as a gene delivery system has been extensively studied in recent years owing to its potential advantages over viral vectors. To achieve this goal, carbon nanotubes have to be functionalized to become compatible with aqueous media and to bind the genetic material. To establish the best conditions for plasmid DNA binding, we compare the dispersion properties of single-, double- and multi-walled carbon nanotubes (SWCNTs, DWCNTs and MWCNTs, respectively) functionalized with a variety of surfactants by non-covalent attachment. The DNA binding properties of the functionalized carbon nanotubes were studied and compared by electrophoresis. Furthermore, a bilayer functionalization method for DNA binding on SWCNTs was developed that utilized RNA-wrapping to solubilize the nanotubes and cationic polymers as a bridge between nanotubes and DNA

Laser-inscribed contact lens sensors for the detection of analytes in the tear fluid

Tears exhibit compositional variations as a response to ocular and systemic metabolic conditions, and they can therefore be used for the assessment of physiological health. Here, microfluidic contact lenses were developed as wearable platforms for in situ tear pH, glucose, protein, and nitrite ions sensing. The microfluidic system was inscribed in commercial contact lenses by CO2 laser ablation. The microchannel consisted on a central ring with four branches, and biosensors were embedded within microcavities located at the branches ends. The device was tested with artificial tears and colorimetric readouts were performed using a smartphone-MATLAB algorithm based on the nearest neighbor model. Sensors responded within a time range of 15 s, and yielded sensitivities of 12.23 nm/pH unit, 1.4 nm/mmol L−1 of glucose, 0.49 nm/g L−1 of proteins, and 0.03 nm/μmol L−1 of nitrites. Contact lens sensing platforms may provide on-eye tears screening with applications in the monitoring of the ocular health both in clinics and at point-of-care settings

No interactions between heparin and atacicept, an antagonist of B cell survival cytokines.

The TNF family ligands, B cell activating factor of the TNF family (BAFF, also known as B lymphocyte stimulator, BLyS) and a proliferation-inducing ligand (APRIL), share the transmembrane activator and calcium-modulator and cyclophilin ligand (CAML)-interactor (TACI) as one of their common receptors. Atacicept, a chimeric recombinant TACI/IgG1-Fc fusion protein, inhibits both ligands. TACI and APRIL also bind to proteoglycans and to heparin that is structurally related to proteoglycans. It is unknown whether the portion of TACI contained in atacicept can bind directly to proteoglycans, or indirectly via APRIL, and whether this could interfere with the anti-coagulant properties of heparin. Binding of atacicept and APRIL to proteoglycan-positive cells was measured by FACS. Activities of heparin and atacicept were measured with activated factor Xa inhibition and cell-based assays. Effects of heparin on circulating atacicept was monitored in mice. Atacicept did not bind to proteoglycan-positive cells, but when complexed to APRIL could do so indirectly via APRIL. Multimers of atacicept obtained after exposure to cysteine or BAFF 60-mer bound directly to proteoglycans. Atacicept alone, or in complex with APRIL, or in a multimeric form did not interfere with heparin activity in vitro. Conversely, heparin did not influence inhibition of BAFF and APRIL by atacicept and did not change circulating levels of atacicept. Lack of detectable interference of APRIL-bound or free atacicept on heparin activity makes it unlikely that atacicept at therapeutic doses will interfere with the function of heparin in vivo

Antibodies That Block or Activate Mouse B Cell Activating Factor of the Tumor Necrosis Factor (TNF) Family (BAFF), Respectively, Induce B Cell Depletion or B Cell Hyperplasia.

B cell activating factor of the TNF family (BAFF), also known as B lymphocyte stimulator, is a ligand required for the generation and maintenance of B lymphocytes. In this study, the ability of different monoclonal antibodies to recognize, inhibit, or activate mouse BAFF was investigated. One of them, a mouse IgG1 named Sandy-2, prevented the binding of BAFF to all of its receptors, BAFF receptor, transmembrane activator and calcium modulating ligand interactor, and B cell maturation antigen, at a stoichiometric ratio; blocked the activity of mouse BAFF on a variety of cell-based reporter assays; and antagonized the prosurvival action of BAFF on primary mouse B cells in vitro A single administration of Sandy-2 in mice induced B cell depletion within 2 weeks, down to levels close to those observed in BAFF-deficient mice. This depletion could then be maintained with a chronic treatment. Sandy-2 and a previously described rat IgG1 antibody, 5A8, also formed a pair suitable for the sensitive detection of endogenous circulating BAFF by ELISA or using a homogenous assay. Interestingly, 5A8 and Sandy-5 displayed activities opposite to that of Sandy-2 by stimulating recombinant BAFF in vitro and endogenous BAFF in vivo These tools will prove useful for the detection and functional manipulation of endogenous mouse BAFF and provide an alternative to the widely used BAFF receptor-Fc decoy receptor for the specific depletion of BAFF in mice

Effect of Palmitic Acid on the Electrical Conductivity of Carbon Nanotubes−Epoxy Resin Composites

We found that the palmitic acid allows an efficient dispersion of carbon nanotubes in the epoxy matrix. We have set up an experimental protocol in order to enhance the CNTs dispersion in epoxy resin. Electrical conductivity is optimal using a 1:1 CNTs to palmitic acid weight ratio. The associated percolation threshold is found between 0.05 and 0.1 wt % CNTs, i.e., between 0.03 and 0.06 vol %. The SEM image shows essentially individual CNTs which is inagreement with conductivity measurements. In comparison with composites without palmitic acid, the use of palmitic acid improves the electrical properties of CNTs-epoxy resin composites

Constraining the magnitude of the Chiral Magnetic Effect with Event Shape Engineering in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76$ TeV

In ultrarelativistic heavy-ion collisions, the event-by-event variation of the elliptic flow $v_2$ reflects fluctuations in the shape of the initial state of the system. This allows to select events with the same centrality but different initial geometry. This selection technique, Event Shape Engineering, has been used in the analysis of charge-dependent two- and three-particle correlations in Pb-Pb collisions at $\sqrt{s_{_{\rm NN}}} =2.76$ TeV. The two-particle correlator $\langle \cos(\varphi_\alpha - \varphi_\beta) \rangle$, calculated for different combinations of charges $\alpha$ and $\beta$, is almost independent of $v_2$ (for a given centrality), while the three-particle correlator $\langle \cos(\varphi_\alpha + \varphi_\beta - 2\Psi_2) \rangle$ scales almost linearly both with the event $v_2$ and charged-particle pseudorapidity density. The charge dependence of the three-particle correlator is often interpreted as evidence for the Chiral Magnetic Effect (CME), a parity violating effect of the strong interaction. However, its measured dependence on $v_2$ points to a large non-CME contribution to the correlator. Comparing the results with Monte Carlo calculations including a magnetic field due to the spectators, the upper limit of the CME signal contribution to the three-particle correlator in the 10-50% centrality interval is found to be 26-33% at 95% confidence level.Comment: 20 pages, 6 captioned figures, 1 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/382

First measurement of Ξc0\Xi_{\rm c}^0 production in pp collisions at s\mathbf{\sqrt{s}} = 7 TeV

The production of the charm-strange baryon $\Xi_{\rm c}^0$ is measured for the first time at the LHC via its semileptonic decay into e$^+\Xi^-\nu_{\rm e}$ in pp collisions at $\sqrt{s}=7$ TeV with the ALICE detector. The transverse momentum ($p_{\rm T}$) differential cross section multiplied by the branching ratio is presented in the interval 1 $<$ $p_{\rm T}$ $<$ 8 GeV/$c$ at mid-rapidity, $|y|$ $<$ 0.5. The transverse momentum dependence of the $\Xi_{\rm c}^0$ baryon production relative to the D$^0$ meson production is compared to predictions of event generators with various tunes of the hadronisation mechanism, which are found to underestimate the measured cross-section ratio.Comment: 22 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/412

Desenvolvimento vegetativo de cultivares de amoreira-preta (<i>Rubus</i> sp.) em sistema orgânico no Município de Laranjeiras do Sul, Paraná, Brasil

A amoreira-preta (Rubus sp.) é uma pequena fruta adaptada a diferentes regiões do Brasil. O trabalho objetivou avaliar o desempenho vegetativo de quatro cultivares sob sistema orgânico, em Laranjeiras do Sul/PR. O delineamento experimental foi de blocos ao acaso, com quatro cultivares (Tupy, Guarani, Cherokee e Xavante) e oito repetições. Foram avaliados os parâmetros vegetativos altura de planta, número de ramos laterais emitidos até dormência e massa fresca de parte aérea podada. Os dados foram submetidos à análise de variância com médias comparadas pelo teste de Tukey, a 5% de probabilidade. As cultivares Tupy e Guarani obtiveram melhor desempenho, diferindo no parâmetro emissão de ramos laterais, sendo que Tupy teve maior média (26,29 ramos) e Guarani menor média (18,25 ramos). As demais cultivares tiveram pior desempenho nestas condições. Considerando os parâmetros avaliados, as cultivares Tupy e Guarani são recomendáveis para cultivo orgânico na região do estudo.Blackberry (Rubus sp.) is a small fruit adapted in different regions of Brazil. The aim of this work was to evaluate the performance of four blackberry cultivars in an organic system in Laranjeiras do Sul/PR. The experiment was designed in randomized block design with four cultivars (Tupy, Guarani, Cherokee and Xavante) and eight replications. The vegetative parameters evaluated were plant height, number of lateral branches issued until dormancy and fresh weight of pruned material. Data were subjected to ANOVA and Tukey’s mean comparison test at 5% probability. The Tupy and Guarani blackberry cultivars had a better performance differing in the parameter issuing lateral branches wich was higher for Tupy (26,29 branches) while the Guarani cultivar showed lower average (18,25 branches). The other cultivars showed the worst performance in these conditions. In conclusion, Tupy and Guarani blackberry cultivars could be recommended to organic cultivation at región of study.Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Desenvolvimento vegetativo de cultivares de amoreira-preta (<i>Rubus</i> sp.) em sistema orgânico no Município de Laranjeiras do Sul, Paraná, Brasil

A amoreira-preta (Rubus sp.) é uma pequena fruta adaptada a diferentes regiões do Brasil. O trabalho objetivou avaliar o desempenho vegetativo de quatro cultivares sob sistema orgânico, em Laranjeiras do Sul/PR. O delineamento experimental foi de blocos ao acaso, com quatro cultivares (Tupy, Guarani, Cherokee e Xavante) e oito repetições. Foram avaliados os parâmetros vegetativos altura de planta, número de ramos laterais emitidos até dormência e massa fresca de parte aérea podada. Os dados foram submetidos à análise de variância com médias comparadas pelo teste de Tukey, a 5% de probabilidade. As cultivares Tupy e Guarani obtiveram melhor desempenho, diferindo no parâmetro emissão de ramos laterais, sendo que Tupy teve maior média (26,29 ramos) e Guarani menor média (18,25 ramos). As demais cultivares tiveram pior desempenho nestas condições. Considerando os parâmetros avaliados, as cultivares Tupy e Guarani são recomendáveis para cultivo orgânico na região do estudo.Blackberry (Rubus sp.) is a small fruit adapted in different regions of Brazil. The aim of this work was to evaluate the performance of four blackberry cultivars in an organic system in Laranjeiras do Sul/PR. The experiment was designed in randomized block design with four cultivars (Tupy, Guarani, Cherokee and Xavante) and eight replications. The vegetative parameters evaluated were plant height, number of lateral branches issued until dormancy and fresh weight of pruned material. Data were subjected to ANOVA and Tukey’s mean comparison test at 5% probability. The Tupy and Guarani blackberry cultivars had a better performance differing in the parameter issuing lateral branches wich was higher for Tupy (26,29 branches) while the Guarani cultivar showed lower average (18,25 branches). The other cultivars showed the worst performance in these conditions. In conclusion, Tupy and Guarani blackberry cultivars could be recommended to organic cultivation at región of study.Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale