Xenogeneic, extracorporeal liver perfusion in primates improves the ratio of branched-chain amino acids to aromatic amino acids (Fischer's ratio)

In fulminant hepatic failure (FHF), the development of hepatic encephalopathy is associated with grossly abnormal concentrations of plasma amino acids (PAA). Normalization of the ratio of branched-chain amino acids to aromatic amino acids (Fischer's ratio) correlates with clinical improvement. This study evaluated changes in PAA metabolism during 4 h of isolated, normothermic extracorporeal liver perfusion using a newly designed system containing human blood and a rhesus monkey liver. Bile and urea production were within the physiological range. Release of the transaminases AST, ALT and LDH were minimal. The ratio of branched (valine, leucine, isoleucine) to aromatic (tyrosine, phenylalanine) amino acids increased significantly. These results indicate that a xenogeneic extracorporeal liver perfusion system is capable of significantly increasing Fischer's ratio and may play a role in treating and bridging patients in FHF in the future

Geometric-phase-induced false electric dipole moment signals for particles in traps

Theories are developed to evaluate Larmor frequency shifts, derived from geometric phases, in experiments to measure electric dipole moments (EDMs) of trapped, atoms, molecules and neutrons. A part of these shifts is proportional to the applied electric field and can be interpreted falsely as an electric dipole moment. A comparison is made between our theoretical predictions for these shifts and some results from our recent experiments, which shows agreement to within the experimental errors of 15 %. The comparison also demonstrates that some trapped particle EDM experiments have reached the sensitivity where stringent precautions are needed to minimise and control such false EDMs. Computer simulations of these processes are also described. They give good agreement with the analytical results and they extend the study by investigating the influence of varying surface reflection laws in the hard walled traps considered. They also explore the possibility to suppress such false EDMs by introducing collisions with buffer gas particles. Some analytic results for frequency shifts proportional to the square of the E-field are also given and there are results for the averaging of the B-field in the absence of an E-field

Greener synthesis of dimethyl carbonate using a novel tin-zirconia/graphene nanocomposite catalyst

© 2017 A green, rapid and continuous hydrothermal flow synthesis (CHFS) route has been employed to synthesise highly efficient and active novel heterogeneous catalysts. Tin doped zirconia (Zr–Sn–O) and tin doped zirconia/graphene nanocomposite (Zr–Sn/GO) have been assessed as suitable heterogeneous catalysts for the synthesis of dimethyl carbonate (DMC). The catalysts have been extensively characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area measurement and X-ray photoelectron spectroscopy (XPS) analysis. Extensive batch studies for the synthesis of DMC via the transesterification of propylene carbonate (PC) and methanol (MeOH) using Zr–Sn/GO catalyst in a solvent free process were also conducted. The effect of various reaction conditions such as reactant molar ratio, catalyst loading, reaction temperature and reaction time has been extensively evaluated. Response surface methodology based on Box-Behneken Design (BBD) was employed to derive optimum conditions for maximising PC conversion and DMC yield. The correlations and interactions between various variables such as MeOH:PC ratio, catalyst loading, reaction temperature, reaction time and stirring speed were extensively studied. A quadratic model by multiple regression analysis for the PC conversion and DMC yield was developed and verified by several methods BBD revealed that optimum conditions for high yield values of DMC are 12.33:1 MeOH:PC molar ratio, 446.7 K, 4.08 h and 300 rpm using 2.9% (w/w) Zr–Sn/GO nanocomposite. The maximum predicted responses at the optimum conditions are 85.1% and 81% for PC conversion and yield of DMC respectively. Experimental results at optimum model predicted reaction conditions agree very well with the model predicted response, where 82.4% PC conversion and 78.2% yield of DMC were obtained. Catalyst reusability and stability studies have been conducted at optimum reaction condition to investigate the long term stability of Zr–Sn/GO and it has been found that the catalyst could be reused more than six times (about 42 h) without losing its catalytic activity. These experimental and model predicted values showed an excellent agreement for tin doped zirconia/graphene nanocomposite as a heterogeneous catalyst for the synthesis of DMC from PC and MeOH

Dynamics of modal power distribution in a multimode semiconductor laser with optical feedback

The dynamics of power distribution between longitudinal modes of a multimode semiconductor laser subjected to external optical feedback is experimentally analyzed in the low-frequency fluctuation regime. Power dropouts in the total light intensity are invariably accompanied by sudden activations of several longitudinal modes. These activations are seen not to be simultaneous to the dropouts, but to occur after them. The phenomenon is statistically analysed in a systematic way, and the corresponding delay is estimated.Comment: 3 pages, 4 figures, revte

Personal and sub-personal: a defence of Dennett's early distinction

Since 1969, when Dennett introduced a distinction between personal and sub‐personal levels of explanation, many philosophers have used ‘sub‐personal’ very loosely, and Dennett himself has abandoned a view of the personal level as genuinely autonomous. I recommend a position in which Dennett's original distinction is crucial, by arguing that the phenomenon called mental causation is on view only at the properly personal level. If one retains the commit‐’ ments incurred by Dennett's early distinction, then one has a satisfactory anti‐physicalistic, anti‐dualist philosophy of mind. It neither interferes with the projects of sub‐personal psychology, nor encourages ; instrumentalism at the personal level. People lose sight of Dennett’s personal/sub-personal distinction because they free it from its philosophical moorings. A distinction that serves a philosophical purpose is typically rooted in doctrine; it cannot be lifted out of context and continue to do its work. So I shall start from Dennett’s distinction as I read it in its original context. And when I speak of ‘the distinction’, I mean to point not only towards the terms that Dennett first used to define it but also towards the philosophical setting within which its work was cut out

Experimental study of fragmentation products in the reactions 112Sn + 112Sn and 124Sn + 124Sn at 1 AGeV

Production cross-sections and longitudinal velocity distributions of the projectile-like residues produced in the reactions 112Sn + 112Sn and 124Sn + 124Sn both at an incident beam energy of 1 AGeV were measured with the high-resolution magnetic spectrometer, the Fragment Separator (FRS) of GSI. For both reactions the characteristics of the velocity distributions and nuclide production cross sections were determined for residues with atomic number Z $\geq$ 10. A comparison of the results of the two reactions is presented.Comment: 14 pages, 12 figure

Efficiency determination of resistive plate chambers for fast quasi-monoenergetic neutrons

Composite detectors made of stainless steel converters and multigap resistive plate chambers have been irradiated with quasi-monoenergetic neutrons with a peak energy of 175MeV. The neutron detection efficiency has been determined using two different methods. The data are in agreement with the output of Monte Carlo simulations. The simulations are then extended to study the response of a hypothetical array made of these detectors to energetic neutrons from a radioactive ion beam experiment.Comment: Submitted to Eur.Phys.J. A; upgraded version correcting some typos and updating ref.