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Matrix protein 2 ectodomain (M2e) is considered an attractive component of a broadly protective, universal influenza A vaccine. Here we challenge the canonical view that antibodies against M2e are the prime effectors of protection. Intranasal immunizations of Balb/c mice with CTA1-3M2e-DD-generated M2e-specific memory CD4 T cells that were I-Adrestricted and critically protected against infection, even in the complete absence of antibodies, as observed in JhD mice. Whereas some M2e-tetramer-specific memory CD4 T cells resided in spleen and lymph nodes, the majority were lung-resident Th17 cells, that rapidly expanded upon a viral challenge infection. Indeed, immunized IL-17A−/−mice were significantly less well protected compared with wild-type mice despite exhibiting comparable antibody levels. Similarly, poor protection was also observed in congenic Balb/B (H-2b) mice, which failed to develop M2e-specific CD4 T cells, but exhibited comparable antibody levels. Lung-resident CD69+CD103lowM2e-specific memory CD4 T cells were αβ TCR+and 50% were Th17 cells that were associated with an early influx of neutrophils after virus challenge. Adoptively transferred M2e memory CD4 T cells were strong helper T cells, which accelerated M2e- but more importantly also hemagglutinin-specific IgG production. Thus, for the first time we demonstrate that M2e-specific memory CD4 T cells are broadly protective.

Matrix protein 2 ectodomain (M2e) is considered an attractive component of a broadly protective, universal influenza A vaccine. Here we challenge the canonical view that antibodies against M2e are the prime effectors of protection. Intranasal immunizations of Balb/c mice with CTA1-3M2e-DD-generated M2e-specific memory CD4 T cells that were I-Adrestricted and critically protected against infection, even in the complete absence of antibodies, as observed in JhD mice. Whereas some M2e-tetramer-specific memory CD4 T cells resided in spleen and lymph nodes, the majority were lung-resident Th17 cells, that rapidly expanded upon a viral challenge infection. Indeed, immunized IL-17A−/−mice were significantly less well protected compared with wild-type mice despite exhibiting comparable antibody levels. Similarly, poor protection was also observed in congenic Balb/B (H-2b) mice, which failed to develop M2e-specific CD4 T cells, but exhibited comparable antibody levels. Lung-resident CD69+CD103lowM2e-specific memory CD4 T cells were αβ TCR+and 50% were Th17 cells that were associated with an early influx of neutrophils after virus challenge. Adoptively transferred M2e memory CD4 T cells were strong helper T cells, which accelerated M2e- but more importantly also hemagglutinin-specific IgG production. Thus, for the first time we demonstrate that M2e-specific memory CD4 T cells are broadly protective.

The present study examined the pathogenesis of interstitial inflammation and fibrosis in antihypertensively treated rats with two-kidney, one-clip hypertension. Hypertensive rats were randomized into four groups: no treatment and moderate, intermediate, and intensified lowering of blood pressure with increasing doses of a vasopeptidase inhibitor for 6 wk. The vasopeptidase inhibitor dose dependently lowered blood pressure. The tubulointerstitial damage was accompanied by a diffuse infiltration of mononuclear cells and circumscript mononuclear inflammatory cell cluster formation consisting mainly of T cells and to a lesser degree of macrophages and B cells. Real-time PCR analyses showed a dose-dependent induction of MCP-1 and the Th1-type chemokines IP10 and Mig as well as their receptor CXCR3 and the Th1 cytokine IFN-γ. In situ hybridization and laser microdissection revealed a strong expression of these Th1-associated transcripts in the clusters and, in the case of MCP-1, also diffusely in the interstitium. The inflammation was accompanied by the appearance of myofibroblasts and synthesis of the fibrogenic factor plasminogen activator inhibitor-1 as well as the collagenase matrix metalloproteinase-2, leading to collagen I upregulation and interstitial scarring. No inflammation or fibrosis was found in normotensive rats treated with the vasopeptidase inhibitor. The renal injury in the clipped kidney is accompanied by compartment-specific chemokine expression and cell cluster formation of Th1 specificity associated with upregulation of fibrogenic proteins and matrix metalloproteinases. These findings suggest that the Th1 chemokines IP10 and Mig as well as their receptor CXCR3 are potential targets for therapeutic interventions in ischemic nephropathy.

Endothelial cells are primary targets for pro-atherosclerotic stressors such as oxidized LDL (ox-LDL). The isoflavone genistein, on the other hand, is suggested to prevent a variety of processes underlying atherosclerosis and cardiovascular diseases. By analyzing the proteome of EA·hy 926 endothelial cells, here we show, that genistein reverses the ox-LDL-induced changes of the steady-state levels of several proteins involved in atherosclerosis. These alterations caused by genistein are functionally linked to the inhibition of ox-LDL induced apoptosis. Keywords: proteomics • atherosclerosis • ox-LDL • apoptosis

This paper presents a detailed analysis of the transport behaviour of the detached plasmas in W7-AS based on an extended numerical study using the EMC3-EIRENE code, aimed at understanding the underlying physics responsible for the geometry-dependent detachment stability observed in W7-AS island divertor experiments. Here, a stable detachment can only be established when the control coils are switched on to generate sufficiently large islands with relatively short connection lengths. Special attention will be paid to a discussion of the carbon radiation, location and dynamics of the radiation layer, the neutral screening efficiency specific to the island divertor geometry and its impact on the detachment stability. Based on the three-dimensional simulation results, a linear stability model is presented in order to obtain some insight into the mechanisms driving the instability. The radiation behaviour and the location and evolution of the radiation zone in the island divertor will be discussed with respect to those of tokamak-MARFEs.

An experimental overview of the detachment process in the W7-AS stellarator with island divertors is given. Results of different spectroscopic methods are combined with those of Langmuir probes and neutral pressure measurements. Two phases of the detachment process are identified: the detachment transition due to the unstable range of the radiative loss function of carbon and a volume recombination phase for densities well above those needed for the onset of detachment. The first phase is characterized by a sudden drop in the temperature at the plasma edge and in the divertor. As a consequence, the particle fluxes at the divertor targets on top and at the bottom are reduced to a different degree, depending on the region. In the second phase, the plasma between the strike lines in the upper divertor is strongly recombining. Simultaneously, a strong carbon radiation belt is observed in the inboard scrape-off layer. The physical mechanisms of both phases are discussed.

In the high-density H-mode of the Stellarator Wendelstein 7-AS, the plasma detaches from the island divertor targets when the line-averaged density exceeds a critical value. This quasi-stationary detachment is found to be partial and shows edge-localized, poloidally asymmetric radiation. The spectroscopic characteristics of the deeply detached plasma are reported, including evidence for volume recombination. The detached plasma radiates up to 90% of the absorbed power with larger contributions from the locations close to magnetic X-points outside the divertor region. The spectral analysis of the Balmer series indicate very high densities and low temperatures at the detached regions. The results of the spectral analysis underline the importance of three-dimensional modelling. An initial comparison is made with the latest results from EMC3-EIRENE modelling.

In the Wendelstein 7-AS stellarator (Renner et al 1989 Plasma Phys. Control. Fusion 31 1579), under particularly high plasma densities, a non-stationary radiation zone is observed to be formed on the inboard side of the torus. It causes a degradation of the diamagnetic energy of up to 50%. The configurational aspects of the magnetic field influence the development of the radiation zone as follows. The critical density is related to the connection length of the magnetic field, i.e. the observed degradation sets in at lower densities for magnetic configurations with large connection lengths. From camera observations, in conjunction with forward calculations, it is found that the radiation zone is located on closed field lines and forms a toroidal belt. Based on complementary observations, it is concluded that the radiation zone is caused by a radiative condensation instability (or multi-faceted asymmetric radiation from the edge). Fluctuations of the radiation zone were recorded using a fast framing camera with a time resolution of 25 µs. Temporal variations as well as spatial movements were observed. The fluctuations were found on various lines-of-sight around the torus with correlation and phase shifts compatible with a toroidal propagation.

AbstractWith Large Helical Device (LHD) and Wendelstein 7-X (W7-X), the development of helical devices is now taking a large step forward on the path to a steady-state fusion reactor. Important issues that need to be settled in these machines are particle flux and heat control and the impact of divertors on plasma performance in future continuously burning fusion plasmas. The divertor concepts that will initially be explored in these large machines were prepared in smaller-scale devices like Heliotron E, Compact Helical System (CHS), and Wendelstein 7-AS (W7-AS). While advanced divertor scenarios relevant for W7-X were already studied in W7-AS, other smaller-scale experiments like Heliotron-J, CHS, and National Compact Stellarator Experiment will be used for the further development of divertor concepts. The two divertor configurations that are being investigated are the helical and the island divertor, as well as the local island divertor, which was successfully demonstrated on CHS and just went into operation on LHD. At present, on its route to a fully closed helical divertor, LHD operates in an open helical divertor configuration. W7-X will be equipped right from the start with an actively cooled discrete island divertor that will allow quasi-continuous operation. The divertor design is very similar to the one explored on W7-AS. For sufficiently large island sizes and not too long field line connection lengths, this divertor gives access to a partially detached quasi-steady-state operating scenario in a newly found high-density H-mode operating regime, which benefits from high energy and low impurity confinement times, with edge radiation levels of up to 90% and sufficient neutral compression in the subdivertor region (>10) for active pumping. The basic physics of the different divertor concepts and associated implementation problems, like asymmetries due to drifts, accessibility of essential operating scenarios, toroidal asymmetries due to symmetry breaking error fields, etc., are discussed.

Stellarators have the intrinsic property of steady state operation. However, on present-day stellarators the pulse length is usually not only limited due to technical reasons, but also by physical problems. Lack of density control and a subsequent radiation collapse terminate the discharges quite often at high densities. To improve the control of the plasma–wall interaction, the island divertor concept was developed for optimized stellarators. To test this divertor concept on W7-AS, all limiters were removed and replaced by ten divertor modules. In subsequent divertor experiments a promising new plasma operational regime has been discovered which is termed `high density H-mode' (HDH-mode). During the transition into that regime a clear reduction of ELM-like events and turbulent fluctuations is observed. The HDH-mode combines good energy confinement with very low impurity confinement resulting in low core radiation, but high edge-localized radiation. Consequently, stationary discharges at densities of typically 2×10²⁰ m⁻³ can be performed within the accessible pulse length of about 1 s. At densities above 3×10²⁰ m⁻³ a controlled transition from attached to partially detached plasmas is observed. The still edge-localized radiation reaches 90&percent; of the heating power so that the power load onto the divertor target plates is further reduced. At a lower toroidal field of 0.9 T average β-values could be raised from earlier 2&percent; to more than 3&percent; in magnetic field configurations with rather smooth flux surfaces at the plasma boundary. The recently obtained results render excellent prospects for W7-X, the larger superconducting successor experiment of W7-AS.

Abstract: A milking process is described for preparing 239Np from 243Am. The process includes the stabilization of Np(IV) with ascorbic acid, isolation of Np(IV) by extraction with TOPO/dodecane and stripping of Np with (NH4)2CO3. The yield amounts to 60%. During milking, about 2% of the 243Am ends up in the scrub which is collected and reprocessed together with the remaining feed after 25 operations using extraction chromatography.

Recombination in a helium and helium-hydrogen plasma was experimentally investigated in the linear divertor simulator NAGDIS-II. To identify the physical mechanisms, electron-ion recombination (EIR) and molecular assisted recombination (MAR), the plasma parameters in the recombining region have been measured. We used spectroscopic techniques on the basis of continuum emission and line emission from highly excited levels due to EIR and Langmuir probes. The dependence of the plasma parameters on the neutral pressure in a pure helium plasma and in a helium-hydrogen mixture shows clearly that recombination is caused by different processes in the two cases. In a pure helium plasma a roll-over and a following decrease of the electron density as well as a monotonic decrease of the electron temperature down to 0.1 eV were observed when increasing the helium pressure. Here EIR is the recombination mechanism. Conversely, when hydrogen is added to the helium plasma, the electron density decreases monotonically while the central electron temperature remains above 1 eV. This particular behaviour in the helium-hydrogen plasma can only be explained by the dominant action of MAR.

W7-AS has recently been equipped with ten open divertor modules in order to experimentally evaluate the island divertor concept. First results are reported in this paper. The new divertors enable access to a new NBI-heated, very high density (up to &barn;_e = 3.5×10²⁰ m^-3) operating regime with promising confinement properties. The energy confinement time increases steeply with density and then saturates. In contrast, the particle and impurity confinement times decrease with increasing density. This allows full density control and quasi-steady-state operation also under conditions of partial detachment from the divertor targets. Radiated power fractions are low to moderate in attached regimes and reach up to about 90% in detachment scenarios. The radiation always stays peaked at the edge. The extremely high densities necessitated the development of non-standard heating techniques for central heating. For the first time efficient heating of an NBI target plasma by electron Bernstein waves (140 GHz, second harmonic) is achieved. In addition, this heating scenario enables fine tuning of the upstream boundary conditions for divertor operation.

Acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) is observed in 5 to 10% of patients treated with high-dose chemotherapies followed by autologous stem cell and bone marrow transplantation. Both diseases are frequently associated with monosomy 7 (-7), trisomy 8 (+8), loss of the long arm of chromosome 5 (-5q), and deletions including the TP53-gene region according to del(17)(p13). In this study, we examined whether these chromosomal aberrations are already detectable in blood stem cells from patients who have all been treated with standard chemotherapies prior to peripheral blood stem cell transplantation (PBSCT). Therefore, we screened peripheral blood derived stem cells obtained at the time of stem cell harvest for the presence of -7, +8, -5q, and del(17)(p13) by fluorescence in situ hybridization (FISH). Our series included 40 patients: 4 patients with Hodgkin's disease, 6 patients with non-Hodgkin-lymphoma (NHL), 1 patient with ALL, 4 patients with plasmocytoma, and 25 patients with solid tumors. Peripheral blood mononuclear cells (PBMC) from eight healthy blood donors served as controls. Assuming a hybridization efficiency of >98%, the cut-off level of non diploid cells was determined for each DNA-probe. None of the stem cell preparations exhibited chromosomal damage. Our findings indicate that chromosomal damage is a rare event in stem cell autografts.

Angiotensin II (ANG II) is a major factor involved in the progression of chronic renal disease. Although the generation of this vasoactive peptide has been investigated in great detail, only a few studies have hitherto addressed the metabolism of ANG II into fragments such as angiotensin III and IV (ANG III, IV) which may exert physiological effects independent of ANG II. Aminopeptidase A (APA) is the major enzyme degrading ANG II. The aim of the current study was to evaluate glomerular APA expression in rats with two-kidney, one-clip hypertension.

Abstract: Objective: The aim of the study was to test the applicability of Ventrak 1550/Capnogard 1265 (V-C) for respiratory dead space (Vd) measurement and to determine anatomic (VDana), physiologic (VDphys), and alveolar dead spaces (VDalv) in ventilated neonates. Design: Prospective study. Setting: Neonatal intensive care unit. Patients: 33 investigations in 22 ventilated neonates; median gestational age 34.5 weeks (range 27–41), median birthweight 2658 g (range 790–3940). Method: The single-breath CO2 test (SBT-CO2) and transcutaneous partial pressure of carbon dioxide (PCO2) were recorded simultaneously and Vd was determined (1) automatically (V-C software), (2) by interactive analysis of the PCO2 volume plot, and (3) manually by Bohr/Enghoff equations using data obtained by V-C. Results: Vd measurements were possible in all cases by method 3 but not possible by methods 1 and 2 in 22 of 33 investigations (67 %), especially in preterm neonates, because of disturbed signals. VDana/kg (1.6 ± 0.6 ml/kg, mean ± SD), VDana/tidal volume (Vt) (0.36 ± 0.09) were lower compared to published data in spontaneously breathing infants, whereas VDphys/kg (2.3 ± 0.9 ml/kg) and VDphys/Vt (0.50 ± 0.12) are comparable to data obtained from the literature. Five minutes after insertion of the sensor (dead space 2.6 ml) into the ventilatory circuit, the transcutaneous PCO2 rose above baseline for 3.2 % (patients > 2500 g) and 5.7 % (patients < 2500 g). The time necessary for one analysis was 50–60 min. Conclusion: In ventilated newborns, dead space measurements were possible only in one-third by SBT-CO2, but in all cases by Bohr/Enghoff equations. Improved software could further reduce the time needed for one analysis.

The Ventrak 1550/Capnogard 1265 (V&C) enables deadspace (VD) measurements to be made in neonates. The aim of our studies was to validate the V&C device for VD measurement in vitro (lung model) and in vivo (adult rabbits). Methods of measurement of VD using the V&C (automatic computation, interactive carbon dioxide-volume plot analysis, Bohr equation) were tested by comparing known added deadspace volumes (VDadd) with calculated VDadd. After producing a change in alveolar (VDalv) and physiological (VDphys) deadspace by in vivo broncho-alveolar lavage, VDalv and VDphys computed automatically were compared with values calculated by the Bohr-Enghoff equations. VDadd was slightly underestimated (absolute error in mean: automatically -0.61 ml; interactively -0.55 ml; Bohr -0.54 ml). The higher the VDadd, the lower the absolute errors and coefficients of variation (cv). The highest cv occurred for automatic analysis (approximately 11%) compared with < 6% for interactive analysis or the Bohr equation. Average differences between results calculated automatically and by the Bohr-Enghoff equation were -0.79 ml for VDalv (95% confidence interval -2.02 to 0.44 ml) and -0.23 ml for VDphys (-0.6 to 0.14 ml). We conclude that the V&C can be used in newborn infants undergoing mechanical ventilation, if changes in VD are < 5 ml, interactive analysis or the Bohr equation should be used.

The Ventrak 1550/Capnogard 1265 (V&C) enables deadspace (VD) measurements to be made in neonates. The aim of our studies was to validate the V&C device for VD measurement in vitro (lung model) and in vivo (adult rabbits). Methods of measurement of VD using the V&C (automatic computation, interactive carbon dioxide-volume plot analysis, Bohr equation) were tested by comparing known added deadspace volumes (VD_add) with calculated VD_add. After producing a change in alveolar (VD_alv) and physiological (VD_phys) deadspace by in vivo bronchoalveolar lavage, VD_alv and VD_phys computed automatically were compared with values calculated by the Bohr-Enghoff equations. VD_add was slightly underestimated (absolute error in mean: automatically -0.61 ml; interactively -0.55 ml; Bohr -0.54 ml). The higher the VD_add, the lower the absolute errors and coefficients of variation (cv). The highest cv occurred for automatic analysis (approximately 11%) compared with &lt;6% for interactive analysis or the Bohr equation. Average differences between results calculated automatically and by the Bohr-Enghoff equation were -0.79 ml for VD_alv (95% confidence interval -2.02 to 0.44 ml) and -0.23 ml for VD_phys (-0.6 to 0.14 ml). We conclude that the V&C can be used in newborn infants undergoing mechanical ventilation. If changes in VD are &lt;5 ml, interactive analysis or the Bohr equation should be used.

The transport characteristics of the aminocephalosporin [3H]cefadroxil have been studied in brush-border membrane vesicles (BBMV) of rat kidney cortex by a rapid filtration technique and by use of a potential sensitive fluorescent dye. Influx of [3H]cefadroxil (0.25 microM) into BBMV as a function of time displayed a pronounced overshoot phenomenon in the presence of a transmembrane pH gradient (pHin > pHout). Evidence for an electrogenic cefadroxil/H+-symport in the presence of an inwardly directed proton gradient is provided by the demonstration of: 1) reduced uptake in the presence of a protonophore; 2) reduced uptake under voltage clamp conditions; and 3) increased uptake in the presence of a valinomycin-induced inside negative K+-diffusion potential. pH-gradient dependent uptake of [3H]cefadroxil as a function of substrate concentration revealed the presence of multiple carrier systems. By kinetic analysis, a high-affinity carrier system (Km, 8.8 +/- 1.3 microM) and a low-affinity system (Km, 2.62 +/- 0.80 mM) could be resolved. The high-affinity transport system was found to be very specific for substrates (cephalosporins and di- and tripeptides) carrying an alpha-amino group. By use of a potential sensitive fluorescent dye 3,3'-dipropylthiadicarbocyanine iodide, the low-affinity transport system was characterized with respect to its driving force and its kinetic features. This transporter was found also to be electrogenic in nature, representing a second cefadroxil/H+-symport system. In summary, our studies demonstrate for the first time uphill transport of cefadroxil in kidney BBMV mediated by multiple carrier systems. Transport is rheogenic, energized by the proton motive force and shared by other aminocephalosporins as well as di- and tripeptides.(ABSTRACT TRUNCATED AT 250 WORDS)

To investigate whether multiple peptide transporters mediate absorption of beta-lactams carrying different charges at physiological pH, we used the human intestinal cell line Caco-2 and Xenopus laevis oocytes expressing the cloned rabbit intestinal peptide transporter PepT1. Characteristics of transport of the anionic cefixime and the zwitterionic cefadroxil were assessed by 1) flux studies using radiolabeled compounds, by 2) measuring changes in pHin in cells and oocytes as a consequence of substrate-mediated proton influx and 3) by applying the two-electrode voltage clamp technique to assess the electrophysiological phenomena associated with beta-lactam transport in oocytes expressing PepT1. Both beta-lactams were rapidly taken up into Caco-2 cells and oocytes expressing PepT1 by a pH-dependent and saturable transport pathway. Mutual inhibition suggested that acidic and zwitterionic compounds may share a common transporter. Cefixime and cefadroxil caused a significant decline in intracellular pH as a consequence of proton coupled substrate influx. Uptake of cefixime and cefadroxil via PepT1 expressed in oocytes was electrogenic indicating that transport of both beta-lactams is associated with movement of net positive charge. The more acidic pH required for rheogenic cefixime uptake in both cell systems, when compared to cefadroxil uptake in both cell systems, when compared to cefadroxil uptake, and the concomitant faster intracellular acidification indicates that cefixime most likely is taken up only in its nonionized form with an additional proton being cotransported. This is supported by the observation that cefixime uptake at different pH correlated significantly with the percentage of the nonionized species being present. From our studies we conclude that a single peptide transport system can mediate electrogenic uptake of the neutral form of beta-lactam antibiotics into intestinal epithelial cells.

With a high-pressure low-temperature differential scanning calorimeter (d.s.c.) developed by Arntz, measurements were performed on the molecular crystal t-butyl chloride (2-chloro-2-methyl-propane) in the temperature range from about 165 k to 260 k at normal and high pressures up to 1750 bar; so far, high pressure investigations, on this substance are unknown. At normal pressure, two solid-solid phase transitions exist, the transition temperatures being 182.8 k (s3 → s2) and 219.2 k (s2 → s1) respectively. With increasing pressure these transition temperatures increase. Additionally a new pressure-induced solid phase s4 was found above 800 bar; the triple point where the three solid phases s1, s2 and s4 coexist is at about 805 bar and 232 k. Furthermore, the transition enthalpies were determined as a function of pressure along the coexistence lines.

Several experiments were conducted in ASDEX Upgrade to prove the suitability of tungsten as a divertor target material under the conditions of a high density and low temperature divertor. The observed fluxes from a tungsten tile into the plasma are low, in keeping with the extremely low sputtering yields. In addition, the very favourable effect of `prompt redeposition' (redeposition during the first gyration) could be confirmed by the experiments. Cooling of the edge region by neon injection seems permissible, i.e. neon impurity sputtering did not increase the eroded fluxes of tungsten. The transport and accumulation behaviour were investigated by means of the laser blow-off technique. No accumulation effects could be observed in ohmic discharges. In discharges with NBI heating but without ICRH, strong accumulation can occur. High heat flux tests were performed on graphite tiles coated with plasma sprayed tungsten, which withstood a thermal load of 15 MW/m² lasting 2 s as well as 1000 cycles of 10 MW/m² for 2 s without disabling damage. Owing to the encouraging results, an experiment using a tungsten divertor is planned in ASDEX Upgrade

Abstract.: The cloned intestinal peptide transporter is capable of electrogenic H+-coupled cotransport of neutral di- and tripeptides and selected peptide mimetics. Since the mechanism by which PepT1 transports substrates that carry a net negative or positive charge at neutral pH is poorly understood, we determined in Xenopus oocytes expressing PepT1 the characteristics of transport of differently charged glycylpeptides. Transport function of PepT1 was assessed by flux studies employing a radiolabeled dipeptide and by the two-electrode voltage-clamp-technique. Our studies show, that the transporter is capable of translocating all substrates by an electrogenic process that follows Michaelis Menten kinetics. Whereas the apparent K0.5 value of a zwitterionic substrate is only moderately affected by alterations in pH or membrane potential, K0.5 values of charged substrates are strongly dependent on both, pH and membrane potential. Whereas the affinity of the anionic dipeptide increased dramatically by lowering the pH, a cationic substrate shows only a weak affinity for PepT1 at all pH values (5.5–8.0). The driving force for uptake is provided mainly by the inside negative transmembrane electrical potential. In addition, affinity for proton interaction with PepT1 was found to depend on membrane potential and proton binding subsequently affects the substrate affinity. Furthermore, our studies suggest, that uptake of the zwitterionic form of a charged substrate contributes to overall transport and that consequently the stoichiometry of the flux-coupling ratios for peptide: H+/H3O+ cotransport may vary depending on pH.

Pool boiling heat transfer coefficients, bubble departure diameters, and nucleation site densities have been measured for binary mixtures of acetone, isopropanol, and water. The measured heat transfer coefficients are compared to the predictions of a correlation developed by Schliinder [1]. Different approaches to determine the ideal heat transfer coefficient required for this correlation are eualuaied.

A numerical study of heat transfer to acetone / isopropanol mixtures boiling on a finned surface was performed using a finite-difference technique. Heat transfer surface temperature, liquid composition, fin geometry, and fin thermal conductivity have been varied to investigate the influence of these parameters on fin-average heat transfer coefficients and on the amount of heat transferred by the finned surface. The results indicate that the significant degradation of heat transfer that is found for boiling of mixtures on plain surfaces can be reduced by using finned heat transfer surfaces.

Abstract: A detection system is described for monitoring on-line radioactive process solutions by solid scintillation counting. The system consists of a flow cell with perspex windows coated with the plastic scintillator MeltilexTM. The cell is confined in a chamber welded to a La Calhène container. Thus the detection device is easily attached to, detached from and transported between glove boxes, and the electronic parts and the multiplers can be kept outside the box containment. Using outside coated windows, the detector responds to gamma radiation, using inside coated windows, agr and beta particles can be detected. Selective measurements can be carried out by installing a chromatographic column in the detector loop. The detection limits of the cell for Am amount to 4·10–9 g Am/ml for outside coated windows and 10–9 g Am/ml for inside coated windows. windows and 10–9 g Am/ml for inside coated windows.

A chromatographic separation can be controlled only by the determination of the separated component concentration in the column effluent. This control is implemented by an in-line scintillation counting procedure during an extraction chromatographic purification of predecontaminated Th-containing fuel solutions from Np and Pu. In addition, the throughput ofthe process feed solution is determined, and the measuring signals of both determinations are used by appropriated control circuits to regulate the process operation and to perceive the process incidents.

Experimental results for subcooled flow-boiling heat transfer to isopropanol/water-mixtures in a vertical annulus during upward flow are reported. The influence of heat flux, flow velocity subcooling and mixture composition on heat transfer in the nucleate boiling region is discussed. The measured subcooled boiling heat transfer coefficients are compared with the predictions of two correlations for saturated boiling suggested in the literature. It was found that these correlations agree well with the present measurements.

Technetium-99m-d,l-hexamethylpropylene amine oxime (Tc-99m-HMPAO) has been developed in our Institute in order to meet the demand of GDR clinicians for a radiopharmaceutical, which allows the examination of regional cerebral blood-flow by SPECT. The present paper informs on synthesis and 13C NMR spectroscopic identification of the ligand d,l-HMPAO as well as its labelling by reconstitution of a sterile, freeze-dried mixture containing d,l-HMPAO, stannous chloride, and sodium chloride with Tc-99m-pertechnetate eluate. Labelling efficiency (more than 90%, the lipophilic component 80-90%) and pattern of products were estimated using tlc and paper chromatography with a combination of three solvent systems. Quality control of the freeze-dried formulation includes methods for quantitative determination of the ligand and of stannous chloride. The ability of Tc-99m-HMPAO to be localized in brain was quantified in rats by organ distribution with time and by autoradiography, showing both high initial uptake, and blood flow-dependent distribution in the brain.

A twin column model was developed for decontamination processes, employing solvent extraction chromatography operated in the breakthrough mode. The model combines the laws for mass transfer between phases with empirical approximations and reproducible experimental observations. A detector is placed between the two columns allowing the acquisition of a full chromatogram without exhausting the decontamination capacity of the unit. A procedure is described to optimize column capacity and decontamination factor.

Spent high enriched U-Th mixed oxide fuels contain small amounts of the actinides Np and Pu. Although these elements cannot be economically recovered for fuel value, current, fuel cycle and waste treatment concepts tend to require that processes be developed to include both elements in one of the Thorex reprocessing effluent streams. Chromatographic separation is described as a method to isolate Pu and Np for subsequent disposal.

Mesangial cells predominantly express platelet-derived growth factor (PDGF)-A chain mRNA and release PDGF. Mesangial cell PDGF-A chain mRNA abundance is regulated by several agents including phorbol esters. We have recently demonstrated that induction of PDGF-A chain mRNA abundance in response to phorbol 12-myristate 13-acetate is primarily due to gene transcription. We have now analyzed the 5'-flanking region of the PDGF-A chain promoter to identify DNA binding protein(s) which have the potential to regulate PDGF-A chain gene transcription in human mesangial cells. DNase I footprint analysis of the 5'-flanking region of the PDGF-A chain promoter identifies a DNase I protected region at the location -82 to -102 corresponding to the sequence 5'-GGCCCGGAATCCGGGGGAGGC-3'. Therefore, nuclear extracts from human mesangial cells contain a protein, PDGF-A-BP-1, that binds to a DNA sequence (-82 to -102) in the promoter region of the PDGF-A chain gene. Gel mobility shift analysis using labeled oligomer corresponding to the binding site for PDGF-A-BP-1 indicates that PDGF-A-BP-1 is induced by phorbol ester in mesangial cells as well as fat-storing cells (> 20 fold). Egr-1 protein does not bind to labeled PDGF-A-BP-1 oligomer and does not compete with the binding of PDGF-A-BP-1. In addition, SP-1 binding sequence does not compete with the binding sequence of the mesangial cell protein. PDGF-A-BP-1 appears to represent a novel protein which is induced by phorbol ester and thus has the potential for an important role in the transcriptional regulation of the PDGF-A chain gene in mesangial cells and other vascular pericytes.

In this paper we describe impurity line emission measurements in the divertor of ASDEX Upgrade during high power neutral beam heated discharges. We focus on detached conditions where the dominating part of the radiation comes from the X-point region. Spatially resolved line emission in the VUV and visible spectral region of the intrinsic carbon and additionally puffed impurities (neon and nitrogen) is presented. A simple interpretation of the line emission profiles is given and they are also compared to the results of bolometry.

Tungsten coated tiles, manufactured by plasma spray on graphite, were mounted in the divertor of the ASDEX Upgrade tokamak and cover almost 90% of the surface facing the plasma in the strike zone. Over 500 plasma discharges, among which around 300 were heated with heating powers up to 10 MW, were performed up to now. The tungsten flux in the divertor was monitored by a WI line at 400.8 nm. In the plasma centre an array of spectral lines at 5 nm emitted by ionisation states around W XXX was monitored. Under normal discharge conditions W-concentrations of around 10 or even lower were found. The influence on the main plasma parameters was negligible. In a few low power discharges accumulation of tungsten occurred and the temperature profile was flattened. The concentrations of the intrinsic impurities carbon and oxygen are comparable to the discharges with graphite divertor. Furthermore, the density-limits and the β-limits remained unchanged and no negative influence on the energy confinement as well as on the H-mode threshold was found.