A folyamatos szubkután glükózmonitorizálás szerepe az intenzív terápiában

A kritikus állapotú betegek stressz-hyperglykaemiájának értékelése az elmúlt évtizedben jelentősen megváltozott. A vércukor szoros kontrolljának mortalitást csökkentő hatását igazolta több jelentős vizsgálat, ugyanakkor az ezt célzó inzulinkezelés megnöveli a hypoglykaemia kockázatát, amely független mortalitási tényező lehet. A hypoglykaemia szempontjából kiemelt jelentőségű a gyermekpopuláció, a fejlődő idegrendszer miatt. Ezek alapján joggal merül fel a vércukorváltozások intenzív osztályos monitorizálásának igénye, különösen gyermek betegeknél. A hagyományos, vérmintából történő vércukor-meghatározások nem tesznek lehetővé kellően szoros monitorizálást. A cukorbetegek számára kifejlesztett, a szövet közti glükóz meghatározásán alapuló módszerek (continuous glucose monitoring) jó alternatívát jelenthetnek az intenzív osztályos monitorizálásra, amennyiben felmérjük a rendszer korlátait. A mérés a szövet közti folyadékban történik, így a szöveti perfúzió változásai zavarhatják a pontosságát. A folyamatos glükózmonitoring módszer intenzív osztályos alkalmazását jelenleg még nem javasolják, amíg a rendszer megbízhatóságáról nem áll rendelkezésre elegendő adat. Összefoglaló közleményükben a szerzők a magyar klinikai gyakorlatban elterjedt Medtronic folyamatos szubkután glükózmonitorizáló rendszert értékelik, részben saját eredményeik alapján. Orv. Hetil., 2013, 154, 1043–1048. | Critical care associated with stress hyperglycaemia has gained a new view in the last decade since the demonstration of the beneficial effects of strong glycaemic control on the mortality in intensive care units. Strong glycaemic control may, however, induce hypoglycaemia, resulting in increased mortality, too. Pediatric population has an increased risk of hypoglycaemia because of the developing central nervous system. In this view there is a strong need for close monitoring of glucose levels in intensive care units. The subcutaneous continuous glucose monitoring developed for diabetes care is an alternative for this purpose instead of regular blood glucose measurements. It is important to know the limitations of subcutaneous continuous glucose monitoring in intensive care. Decreased tissue perfusion may disturb the results of subcutaneous continuous glucose monitoring, because the measurement occurs in interstitial fluid. The routine use of subcutaneous continuous glucose monitoring in intensive care units is not recommended yet until sufficient data on the reliability of the system are available. The Medtronic subcutaneous continuous glucose monitoring system is evaluated in the review partly based on the authors own results. Orv. Hetil., 2013, 154, 1043–1048

Far-Infrared Excitations below the Kohn Mode: Internal Motion in a Quantum Dot

We have investigated the far-infrared response of quantum dots in modulation doped GaAs heterostructures. We observe novel modes at frequencies below the center-of-mass Kohn mode. Comparison with Hartree-RPA calculations show that these modes arise from the flattened potential in our field-effect confined quantum dots. They reflect pronounced relative motion of the charge density with respect to the center-of-mass.Comment: 8 pages, LaTeX with integrated 6 PostScript figure

Zero-field thermopower of a thin heterostructure membrane with a 2D electron gas

We study the low-temperature thermopower of micron sized, free-standing membranes containing a two-dimensional electron system. Suspended membranes of 320 nm thickness including a high electron mobility structure in Hall bar geometry of 34 {\mu}m length are prepared from GaAs/AlGaAs heterostructures grown by molecular beam epitaxy. Joule heating on the central region of the membrane generates a thermal gradient with respect to the suspension points where the membrane is attached to cold reservoirs. Temperature measurements on the membrane reveal strong thermal gradients due to the low thermal conductivity. We measure the zero-field thermopower and find that the phonon-drag contribution is suppressed at low temperatures up to 7 K.Comment: 5 page

The Impact of Retirement on Cardiovascular Disease and Its Risk Factors: A Systematic Review of Longitudinal Studies

BACKGROUND AND OBJECTIVES: People are now spending longer in retirement than ever before and retirement has been found to influence health. This study systematically reviewed the impact of retirement on cardiovascular disease (CVD) and its risk factors (metabolic risk factors, blood biomarkers, physical activity, smoking, drinking, and diet). RESEARCH DESIGN AND METHODS: Longitudinal studies published in Medline, Embase, Social Science Citation Index, PsycINFO, and Social Policy and Practice were searched. No language restrictions were applied if there was an English abstract. Eighty-two longitudinal studies were included after critical appraisals. RESULTS: Studies in the United States often found no significant effect of retirement on CVD, while studies in European countries, except France, showed a detrimental effect of retirement on CVD. Results from the United States and several European countries consistently show that retirement increase adiposity measures among those retired from physically demanding jobs. For diabetes and hypertension, five out of nine studies suggest no effect of retirement. Retirement has been repeatedly linked to increasing leisure-time physical activity but may reduce work- and transport-related physical activity in turn. Most studies showed that retirement either decreased smoking or had no effect on smoking. The evidence did not show a clear conclusion on drinking. Only a few studies have assessed the impact on diet and blood biomarkers. DISCUSSION AND IMPLICATIONS: Effect of retirement varies according to the health outcomes studied and country of the study population. Policy concerning extending the retirement age needs to focus on ensuring they are suited to the individual

On the adhesion-velocity relation and length adaptation of motile cells on stepped fibronectin lanes

The biphasic adhesion-velocity relation is a universal observation in mesenchymal cell motility. It has been explained by adhesion-promoted forces pushing the front and resisting motion at the rear. Yet, there is little quantitative understanding of how these forces control cell velocity. We study motion of MDA-MB-231 cells on microlanes with fields of alternating Fibronectin densities to address this topic and derive a mathematical model from the leading-edge force balance and the force-dependent polymerization rate. It reproduces quantitatively our measured adhesion-velocity relation and results with keratocytes, PtK1 cells, and CHO cells. Our results confirm that the force pushing the leading-edge membrane drives lamellipodial retrograde flow. Forces resisting motion originate along the whole cell length. All motion-related forces are controlled by adhesion and velocity, which allows motion, even with higher Fibronectin density at the rear than at the front. We find the pathway from Fibronectin density to adhesion structures to involve strong positive feedbacks. Suppressing myosin activity reduces the positive feedback. At transitions between different Fibronectin densities, steady motion is perturbed and leads to changes of cell length and front and rear velocity. Cells exhibit an intrinsic length set by adhesion strength, which, together with the length dynamics, suggests a spring-like front-rear interaction force. We provide a quantitative mechanistic picture of the adhesion-velocity relation and cell response to adhesion changes integrating force-dependent polymerization, retrograde flow, positive feedback from integrin to adhesion structures, and spring-like front-rear interaction

Rho-Omega Mixing and the Pion Form Factor in the Time-like Region

We determine the magnitude, phase, and $s$-dependence of $\rho$-$\omega$ ``mixing'' in the pion form factor in the time-like region through fits to e^+e^- \ra \pi^+ \pi^- data. The associated systematic errors in these quantities, arising from the functional form used to fit the $\rho$ resonance, are small. The systematic errors in the $\rho$ mass and width, however, are larger than previously estimated.Comment: 20 pages, REVTeX, epsfig, 2 ps figures, minor change

Vector meson dominance and the rho meson

We discuss the properties of vector mesons, in particular the rho^0, in the context of the Hidden Local Symmetry (HLS) model. This provides a unified framework to study several aspects of the low energy QCD sector. Firstly, we show that in the HLS model the physical photon is massless, without requiring off field diagonalization. We then demonstrate the equivalence of HLS and the two existing representations of vector meson dominance, VMD1 and VMD2, at both tree level and one loop order. Finally the S matrix pole position is shown to provide a model and process independent means of specifying the rho mass and width, in contrast to the real axis prescription currently used in the Particle Data Group tables.Comment: 18 pages, REVTE

Rescattering and chiral dynamics in B\to \rho\pi decay

We examine the role of B^0(\bar B^0) \to \sigma \pi^0 \to \pi^+\pi^- \pi^0 decay in the Dalitz plot analysis of B^0 (\bar B^0) \to \rho\pi \to \pi^+\pi^-\pi^0 decays, employed to extract the CKM parameter \alpha. The \sigma \pi channel is significant because it can break the relationship between the penguin contributions in B\to\rho^0\pi^0, B\to\rho^+\pi^-, and B\to\rho^-\pi^+ decays consequent to an assumption of isospin symmetry. Its presence thus mimics the effect of isospin violation. The \sigma\pi^0 state is of definite CP, however; we demonstrate that the B\to\rho\pi analysis can be generalized to include this channel without difficulty. The \sigma or f_0(400-1200) ``meson'' is a broad I=J=0 enhancement driven by strong \pi\pi rescattering; a suitable scalar form factor is constrained by the chiral dynamics of low-energy hadron-hadron interactions - it is rather different from the relativistic Breit-Wigner form adopted in earlier B\to\sigma\pi and D\to\sigma\pi analyses. We show that the use of this scalar form factor leads to an improved theoretical understanding of the measured ratio Br(\bar B^0 \to \rho^\mp \pi^\pm) / Br(B^-\to \rho^0 \pi^-).Comment: 26 pages, 8 figs, published version. typos fixed, minor change