The influence of surface morphology and wettability on the inflammatory response against poly(L-lactic acid):A semi-quantitative study with monoclonal antibodies

In this study, the influence of surface morphology and wettability of both degradable and nondegradable polymer films on the inflammatory response after subcutaneous implantation in the rat was investigated. Degradable nonporous, porous, and combi (porous with a nonporous layer on one side) poly(L-lactic acid) (PLLA) films and nondegradable polytetrafluoroethylene (PTFE) and (porous) expanded PTFE (e-PTFE) were used. Contact angles measurements indicate that PLLA is more hydrophillic than PTFE. Assessment of the inflammatory response was performed after various periods of implantation (up till 180 days), with both conventional light microscopy and immunohistochemistry using monoclonal antibodies (mAbs). The inflammatory response observed initially can largely be considered as part of the wound healing reaction, and up till day 40 the inflammatory response against PLLA was minimally more intense than against PTFE (porous as well as nonporous). From day 40 on, the PLLA films provoke a more intense inflammatory response as compared to the PTFE films. Both porous PLLA and the porous side of the combi PLLA film provoke a more intense inflammatory response than nonporous PLLA and the nonporous side of the combi PLLA film, respectively. In general, PTFE and e-PTFE films provoke an inflammatory response which is minimally more intense than the one provoked by the sham operation. Almost no ingrowth of tissue was observed in the porous e-PTFE films. In contrast, there was abundant tissue ingrowth in and an inflammatory response against porous PLLA. It can be concluded that biodegradable PLLA films provoke a more intense inflammatory response than nondegradable PTFE films. Also, porosity enhances the inflammatory response. However, porosity enhances the inflammatory response only when the wettability of a biomaterial permits cellular ingrowth

Biodegradation of porous versus non-porous poly(L-lactic acid) films

The influence of porosity on the degradation rate of poly(L-lactic acid) (PLLA) films was investigated in vitro and in vivo. Non-porous, porous and “combi” (porous with a non-porous layer) PLLA films were used. Changes in Mw, Mn, polydispersity (Mw/Mn) ratio, melting temperature (Tm), heat of fusion, tensile strength, E-modulus, mass and the remaining surface area of cross-sections of the PLLA films were measured. In general, during the degradation process, the porous film has the highest Mw, Mn, Mw/Mn ratio and Tm, while the non-porous film has the lowest. In contrast, the highest heat of fusion values were observed for the non-porous film, indicating the presence of relatively smaller molecules forming crystalline domains more easily. The tensile strength and E-modulus of the non-porous film decrease faster than those of the porous and the combi film. None of the three types of films showed massive mass loss in vitro nor a significant decrease in remaining polymer surface area in light microscopical sections in vitro and in vivo. Heavy surface erosion of the non-porous layer of the combi film was observed after 180 days, turning the combi film into a porous film. This is also indicated by the changes in tensile strength, Mw, Mw/Mn, Tm and heat of fusion as a function of time. It is concluded that non-porous PLLA degrades faster than porous PLLA. Thus, in our model, porosity is an important determinant of the degradation rate of PLLA films

Generalised Moore spectra in a triangulated category

In this paper we consider a construction in an arbitrary triangulated category T which resembles the notion of a Moore spectrum in algebraic topology. Namely, given a compact object C of T satisfying some finite tilting assumptions, we obtain a functor which "approximates" objects of the module category of the endomorphism algebra of C in T. This generalises and extends a construction of Jorgensen in connection with lifts of certain homological functors of derived categories. We show that this new functor is well-behaved with respect to short exact sequences and distinguished triangles, and as a consequence we obtain a new way of embedding the module category in a triangulated category. As an example of the theory, we recover Keller's canonical embedding of the module category of a path algebra of a quiver with no oriented cycles into its u-cluster category for u>1.Comment: 26 pages, improvement to exposition of the proof of Theorem 3.

Quantification of afatinib, alectinib, crizotinib and osimertinib in human plasma by liquid chromatography/triple-quadrupole mass spectrometry; focusing on the stability of osimertinib

The development and full validation of a sensitive and selective ultra-performance liquid chromatography/ tandem mass spectrometry (UPLC–MS/MS) method are described for the simultaneous analysis of afatinib, alectinib, crizotinib and osimertinib in human lithium heparinized plasma. Afatinib-d6, crizotinib-d5 and erlotinib-d6 were used as internal standards. Given osimertinib's instability in plasma and whole blood at ambient temperature, samples should be solely processed on ice (T = 0 °C). Chromatographic separation was obtained on an Acquity UPLC ® BEH C18; 2.1 × 50 mm, 1.7 μm column, which was eluted with 0.400 mL/minute flow on a linear gradient, consisting of 10 mM ammonium formate (pH 4.5) and acetonitrile. Calibration curves for all compounds were linear for concentration ranges of 1.00 to 100 ng/mL for afatinib and 10.0 to 1000 ng/mL for alectinib, crizotinib and osimertinib, herewith validating the lower limits of quantification at 1.00 ng/mL for afatinib and 10.0 ng/mL for alectinib, crizotinib and osimertinib. Within-run and between-run precision measurements fell within 10.2%, with accuracy ranging from 89.2 to 110%

Order in extremal trajectories

Given a chaotic dynamical system and a time interval in which some quantity takes an unusually large average value, what can we say of the trajectory that yields this deviation? As an example, we study the trajectories of the archetypical chaotic system, the baker's map. We show that, out of all irregular trajectories, a large-deviation requirement selects (isolated) orbits that are periodic or quasiperiodic. We discuss what the relevance of this calculation may be for dynamical systems and for glasses

Photon-Phonon-assisted tunneling through a single-molecular quantum dot

Based on exactly mapping of a many-body electron-phonon interaction problem onto a one-body problem, we apply the well-established nonequilibrium Green function technique to solve the time-dependent phonon-assisted tunneling at low temperature through a single-molecular quantum dot connected to two leads, which is subject to a microwave irradiation field. It is found that in the presence of the electron-phonon interaction and the microwave irradiation field, the time-average transmission and the nonlinear differential conductance display additional peaks due to pure photon absorption or emission processes and photon-absorption-assisted phonon emission processes. The variation of the time-average current with frequency of the microwave irradiation field is also studied.Comment: 9 pages, 6 figures, submitted to Phys. Rev. B. accepted by Phys. Rev.

Ancient Gondwana break-up explains the distribution of the mycoheterotrophic family Corsiaceae (Liliales)

Plant science

An intermediate-depth source of hydrothermal 3He and dissolved iron in the North Pacific

We observed large water column anomalies in helium isotopes and trace metal concentrations above the Loihi Seamount. The 3He/4He of the added helium was 27.3 times the atmospheric ratio, clearly marking its origin to a primitive mantle plume. The dissolved iron to 3He ratio (dFe:3He) exported to surrounding waters was 9.3 ± 0.3 × 106. We observed the Loihi 3He and dFe “signal” at a depth of 1100 m at several stations within ∼100 – 1000 km of Loihi, which exhibited a distal dFe:3He ratio of ∼4 × 106, about half the proximal ratio. These ratios were remarkably similar to those observed over and near the Southern East Pacific Rise (SEPR) despite greatly contrasting geochemical and volcanictectonic origins. In contrast, the proximal and distal dMn:3He ratios were both ∼ 1 × 106, less than half of that observed at the SEPR. Dissolved methane was minimally enriched in waters above Loihi Seamount and was distally absent. Using an idealized regional-scale model we replicated the historically observed regional 3He distribution, requiring a hydrothermal 3He source from Loihi of 10.4 ± 4.2 mola−1, ∼2% of the global abyssal hydrothermal 3He flux. From this we compute a corresponding dFe flux of ∼40 Mmola−1. Global circulation model simulations suggest that the Loihi-influenced waters eventually upwell along the west coast of North America, also extending into the shallow northwest Pacific, making it a possibly important determinant of marine primary production in the subpolar North Pacific

Spectroscopy of 18^{18}Na: Bridging the two-proton radioactivity of 19^{19}Mg

The unbound nucleus $^{18}$Na, the intermediate nucleus in the two-proton radioactivity of $^{19}$Mg, was studied by the measurement of the resonant elastic scattering reaction $^{17}$Ne(p,$^{17}$Ne)p performed at 4 A.MeV. Spectroscopic properties of the low-lying states were obtained in a R-matrix analysis of the excitation function. Using these new results, we show that the lifetime of the $^{19}$Mg radioactivity can be understood assuming a sequential emission of two protons via low energy tails of $^{18}$Na resonances