The influence of portal blood upon lipid metabolism in normal and diabetic dogs and baboons

It has been reported that hyperlipidemia can be alleviated in human beings with an end to side portacaval shunt. Understanding the mechanism of the effect has important implications, including the possibility of devising other ways of lowering serum lipid levels. In this investigation, the influence of splanchnic venous blood on lipid metabolism was evaluated in dogs and baboons by altering the portal venous inflow to all, or portions, of the liver and by measuring the effects on different end points, including the serum lipid concentrations and the rate of hepatic lipid synthesis. In other studies, analyses have been made regarding the effect of alloxan induced insulinopenia and of total pancreatectomy on these processes. The results indicate that the effect of complete portal diversion upon serum lipids is mainly due to diversion of the hormone rich venous return from the upper splanchnic organs, although the bypass of the nutritionally rich blood returning from the intestines may play a secondary role. Therefore, a reduction of hepatic lipid synthesis is an important, although not necessarily the sole, factor in the antilipidemic influence of portacaval shunt. The effects upon synthesis and blood lipids are due more to the diversion of endogenous hormones than to the bypass of intestinal nutrients. The substances in portal venous blood that subserve hepatic lipid metabolism are presumably largely the same as the hepatotrophic factors which have been described before as profoundly affecting hepatic structure, function, and the capacity for regeneration. These portal blood factors are multiple and interrelated, but the single most important one seems to be insulin

A collective scattering system for measuring electron gyroscale fluctuations on the National Spherical Torus Experiment

A collective scattering system has been installed on the National Spherical Torus Experiment (NSTX) to measure electron gyroscale fluctuations in NSTX plasmas. The system measures fluctuations with k(perpendicular to)rho(e)less than or similar to 0.6 and k(perpendicular to)less than or similar to 20 cm(-1). Up to five distinct wavenumbers are measured simultaneously, and the large toroidal curvature of NSTX plasmas provides enhanced spatial localization. Steerable optics can position the scattering volume throughout the plasma from the magnetic axis to the outboard edge. Initial measurements indicate rich turbulent dynamics on the electron gyroscale. The system will be a valuable tool for investigating the connection between electron temperature gradient turbulence and electron thermal transport in NSTX plasmas.X1137sciescopu

The effect of diabetes mellitus on portal blood hepatotrophic factors in dogs

Ten nondiabetic dogs were submitted to a procedure called splanchnic division which directed the nutrient rich venous return from the intestines into the left lobes of the liver and the hormone rich pancreatico gastroduodeno splenic venous return into the right lobes. Two mth later, the right lobes had undergone the expected gross and microscopic hypertrophy. Compared with the abnormal shrunken and glycogen depleted hepatocytes of the left lobes, the large and otherwise normal hepatocytes of the right lobes had a higher rate of cell division as judged by microscopic examination, measurements of deoxyribonucleic acid synthesis and the results of autoradiography. Both sides had greater cell replication than in the livers of normal unaltered dogs. The dominance of the right lobes following splanchnic division was almost completely eliminated by the prior creation of alloxan induced diabetes in 4 dogs and by the performance of total pancreatectomy at the same time as splanchnic division in 6 dogs. In these 10 diabetic dogs, which were treated with Sc administered insulin for the 2 mth period of the postoperative study, hepatic lobar and cell size were nearly equal on both sides. By light and electron microscopy, the hepatocytes on both sides had abnormalities, somewhat less pronounced on the right. However, the most active cell division was now transferred to the left lobes. The results with alloxan induced diabetes were similar to those after total pancreatectomy, except that lipid deposits were less on both liver sides in the alloxan experiments, and the glycogen was selectively reduced in the right lobes. The latter finding presumably was due to the continued action of glucagon in dogs made diabetic with alloxan. 12 nondiabetic dogs had a procedure called partial portacaval transposition which directed systemic venous blood from the hindquarters, kidneys and adrenal glands into the left lobes of the liver and the total splanchnic venous return into the right lobes. Two mth later, the degree of relative hypertrophy and hyperplasia of the glycogen rich right lobes was even greater than after splanchnic division, as was the morphologic damage to the left lobar hepatocytes. The degree of right lobar hypertrophy following partial portacaval transposition was reduced but not eliminated by pre existing alloxan induced diabetes in 4 dogs and by concomitant total pancreatectomy in 6 more dogs. The dogs were Sc treated with insulin. Structurally, the hepatocytes on the right side after 2 mth were in better condition than were those on the left, although both were abnormal. The dominance of cell division on the right side was reduced, as judged by standard microscopy and by autoradiography, but there was not a shifting of sides. The biochemical analyses reflected the presence or absence of glucagon. These findings are consistent with the earlier multifactorial hypothesis which holds that portal hepatotrophic factors are mainly interreacting hormones generated by splanchnic organs and delivered straight to the liver and that the hormone interrelationships might have augmented significance because of the high concentration of nutritional substrate in the same venous blood. The observations also substantiate by direct testing the suggestion that insulin is the most important hepatotrophic factor and that it profoundly affects many aspects of liver cell structure, division and function

From Molecular Cores to Planet-forming Disks with SIRTF

The SIRTF mission and the Legacy programs will provide coherent data bases for extra-galactic and Galactic science that will rapidly become available to researchers through a public archive. The capabilities of SIRTF and the six legacy programs are described briefly. Then the cores to disks (c2d) program is described in more detail. The c2d program will use all three SIRTF instruments (IRAC, MIPS, and IRS) to observe sources from molecular cores to protoplanetary disks, with a wide range of cloud masses, stellar masses, and star-forming environments. The SIRTF data will stimulate many follow-up studies, both with SIRTF and with other instruments.Comment: 6 pages, from Fourth Cologne-Bonn-Zermatt-Symposium, The Dense Interstellar Matter in Galaxie

Effect of halide-mixing on the switching behaviors of organic-inorganic hybrid perovskite memory

Mixed halide perovskite materials are actively researched for solar cells with high efficiency. Their hysteresis which originates from the movement of defects make perovskite a candidate for resistive switching memory devices. We demonstrate the resistive switching device based on mixed-halide organic-inorganic hybrid perovskite CH3NH3PbI3−xBrx (x = 0, 1, 2, 3). Solvent engineering is used to deposit the homogeneous CH3NH3PbI3−xBrx layer on the indium-tin oxide-coated glass substrates. The memory device based on CH3NH3PbI3−xBrx exhibits write endurance and long retention, which indicate reproducible and reliable memory properties. According to the increase in Br contents in CH3NH3PbI3−xBrx the set electric field required to make the device from low resistance state to high resistance state decreases. This result is in accord with the theoretical calculation of migration barriers, that is the barrier to ionic migration in perovskites is found to be lower for Br− (0.23 eV) than for I− (0.29–0.30 eV). The resistive switching may be the result of halide vacancy defects and formation of conductive filaments under electric field in the mixed perovskite layer. It is observed that enhancement in operating voltage can be achieved by controlling the halide contents in the film.1119Ysciescopu

Resonance Raman study of the A-band short-time photodissociation dynamics of axial and equatorial conformers of iodocyclopentane

We have obtained resonance Raman spectra of iodocyclopentane in cyclohexane solution at three excitation wavelengths resonant with the A-band absorption. The A-band resonance Raman spectral bands can be assigned to fundamentals, overtones, and combination bands of seven axial conformer and eight equatorial conformer Franck-Condon active modes. The resonance Raman and absorption cross sections were simultaneously simulated using wave packet calculations and a simple model. The best fit parameters of the simulations and the normal mode descriptions were used to determine the A-band short-time photodissociation dynamics of the axial and equatorial conformers of iodocyclopentane. The axial and equatorial conformers exhibit noticeably different short-time photodissociation dynamics that suggest that the C-I bond cleavage process is conformation dependent. The axial conformer short-time photodissociation dynamics have larger changes in the carbon-carbon stretch and three carbon atom bending motions as well as the torsional motion about the α and β carbon atom bond. The CCI bending motions for the axial and equatorial conformers of iodocyclopentane as well as previously reported results for the equatorial conformer of iodocyclohexane are significantly smaller than CCI bending motions found for most noncyclic iodoalkanes examined so far. This suggests that the cyclic backbone restricts the initial motion of the C-I bond cleavage along the CCI bend in iodocycloalkanes compared to the noncyclic iodoalkanes. © 1999 American Institute of Physics.published_or_final_versio

Diffuse optical tomography to investigate the newborn brain

Over the past 15 years, functional near-infrared spectroscopy (fNIRS) has emerged as a powerful technology for studying the developing brain. Diffuse optical tomography (DOT) is an extension of fNIRS that combines hemodynamic information from dense optical sensor arrays over a wide field of view. Using image reconstruction techniques, DOT can provide images of the hemodynamic correlates to neural function that are comparable to those produced by functional magnetic resonance imaging. This review article explains the principles of DOT, and highlights the growing literature on the use of DOT in the study of healthy development of the infant brain, and the study of novel pathophysiology in infants with brain injury. Current challenges, particularly around instrumentation and image reconstruction, will be discussed, as will the future of this growing field, with particular focus on whole-brain, time-resolved DOT

Two-dimensional imaging of edge-localized modes in KSTAR plasmas unperturbed and perturbed by n=1 external magnetic fields

The temporal evolution of edge-localized modes (ELMs) has been studied using a 2-D electron cyclotron emission imaging system in the KSTAR tokamak. The ELMs are observed to evolve in three distinctive stages: the initial linear growth of multiple filamentary structures having a net poloidal rotation, the interim state of regularly spaced saturated filaments, and the final crash through a short transient phase characterized by abrupt changes in the relative amplitudes and distance among filaments. The crash phase, typically consisted of multiple bursts of a single filament, involves a complex dynamics, poloidal elongation of the bursting filament, development of a fingerlike bulge, and fast localized burst through the finger. Substantial alterations of the ELM dynamics, such as mode number, poloidal rotation, and crash time scale, have been observed under external magnetic perturbations with the toroidal mode number n = 1. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694842]X1125sciescopu

Growth and nutrient uptake responses of ‘Seolhyang’ strawberry to various ratios of ammonium to nitrate nitrogen in nutrient solution culture using inert media

The effect of the variation of NH4+:NO3− ratios (meq/l: 0:100, 40:60, 50:50, 65:35 and 100:0) in the nutrient solution on strawberry (Fragaria × ananassa var Seolhyang) growth was evaluated. A mixture of large particle size (2 to 5 mm) and small particle size (smaller than 1 mm) of perlite was used as growing substrate and the nutrient solutions were applied once a week to the root substrate. The growth responses were determined 120 days after transplanting. The use of NO3− as the sole source of nitrogen in the nutrient solution resulted in the highest vegetative growth among the treatments tested. On the contrary, the exclusive use of NH4+ in the nutrient solution suppressed plant growth severely. The initial symptoms of ammonium toxicity appeared on the lower leaves, with the curling down of the old leaves. The margins turned brown and finally died. The introduction of the two nitrogen forms as the treatment ratio 60:40 (NH4+:NO3−) resulted in the optimal growth performance and nutrient uptake of this variety. The rate K/Ca+Mg=0.57, which was close to the best rate 0.67, allowed the optimal uptake of all nutrients. The data of the growth characteristics, nutrient content and electrical conductivity (EC) and pH were subjected to a polynomial regression analysis. The results show a high correlation between these data and the variation of NH4+:NO3− ratios. The values of the fresh and dry weight and N content of above-ground plant tissue to this variation were linear, with R2 coefficients of 0.95***, 0.94**, and 0.71*. The changes in the NO3− concentration in the petiole sap, EC and pH of the root substrate were quadratic, with a coefficients of R2= 0.99***, 0.98***, and 0.73*.Key words: Growth characteristics, NH4+: NO3− ratios, nutrient content, strawberry

On Glauber modes in Soft-Collinear Effective Theory

Gluon interactions involving spectator partons in collisions at hadronic machines are investigated. We find a class of examples in which a mode, called Glauber gluons, must be introduced to the effective theory for consistency.Comment: 19 pages, three figures. Uses JHEP3.cl