Renal prostaglandins and thromboxane A2 lack a functional significance in the genesis of protein-induced glomerular hyperfiltration in human renal disease

Ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) was purified from an obligately autotrophic hydrogen-oxidizing bacterium, Hydrogenovibrio marinus MH-110. The protein has a M(r) value of approximately 110,000, and is composed of two identical subunits of 55,000. To our knowledge, the existence of L2-form RubisCO in a chemolithoautotrophic bacterium is first reported in this paper. The N-terminal amino acid sequence determination of the purified enzyme showed high homology with those of the L2-form RubisCO of Rhodospirillum rubrum and the Lx-form RubisCO from Rhodobacter sphaeroides.     

Reduced central serotonin transporters in alcoholism

OBJECTIVE: Dysfunction of monoamine uptake mechanisms has been implicated in the pathogenesis of alcohol dependence. The authors explored whether serotonergic dysfunction is associated with anxiety and depression, which increase the risk of relapse in alcoholics. METHOD: The availability of serotonin and dopamine transporters in 22 male alcoholics and 13 healthy male volunteers was measured with the use of [123I] beta-CIT and single photon emission computed tomography, and psychopathological correlates were assessed. RESULTS: A significant reduction (a mean of about 30%) in the availability of brainstem serotonin transporters was found in the alcoholics, which was significantly correlated with lifetime alcohol consumption and with ratings of depression and anxiety during withdrawal. CONCLUSIONS: The findings support the hypothesis of serotonergic dysfunction in alcoholism and in withdrawal-emergent depressive symptoms.     

Water reducers for the high alumina cement-silica fume system

High early strength mortars or concretes can be produced with high alumina cement. However, at later ages, particularly at temperatures higher than 20°C, there is a strength loss caused by a transformation of hexagonal hydrates into the cubic form. Silica fume is capable of hindering or blocking this transformation. However, a water reducing admixture is required to counterbalance the higher amount of mixing water caused by the very high specific surface area of silica fume. Since traditional water reducers (based on sulphonated naphtalene or melamine polymers) are not effective with high alumina cement, two alternative candidates have been tested: sodium tripoliphosphate and carboxylic acrylic ester. The sodium tripoliphosphate admixture is capable of reducing the mixing water; however, the simultaneous presence of silica fume and sodium tripoliphosphate causes a surprising and not yet fully-explained strength loss (only at 20°C with liquid water), although the transformation of hexagonal hydrates into the cubic form is truly hindered. In the presence of the carboxylic acrylic ester admixture, the amount of mixing water is reduced without any side effect on the strength loss of the high alumina cement-silica fume system. Therefore, the combination of silica fume with carboxylic acrylic ester appears to be a successful solution to produce mortars or concrete mixes based on high alumina cement content without any strength loss at later ages.

---

Résumé Des mortiers et des bétons développant des résistances mécaniques élevées à court terme peuvent être produits avec les ciments alumineux. Toutefois, au cours du temps, en particulier pour des températures supérieures à 20°C, une diminution de la résistance mécanique survient suite à la transformation des hydrates hexagonaux en structure cubique. La fumée de silice est capable de ralentir ou de bloquer cette transformation. Toutefois, il faut ajouter un réducteur d'eau afin d'équilibrer la plus haute teneur en eau de gachage requise par la surface spécifique importante de la fumée de silice. Puisque les réducteurs d'eau traditionnels (basés sur le naphtalène sulphonate ou sur la mélamine) n'ont pas d'action sur les ciments alumineux, deux produits alternatifs ont été testés: le tripolyphosphate de sodium et l'ester carboxylique acrylique. Le tripolyphosphate de sodium est capable de réduire l'eau de gachage, mais la présence simultanée de fumée de silice et de tripolyphosphate de sodium conduit à une surprenante et non encore expliquée diminution de la résistance (seulement à 20°C avec l'eau liquide), bien que la transformation des hydrates hexagonaux en hydrate cubique soit vraiment limitée. En présence d'ester carboxylique acrylique, la quantité d'eau de gachage est réduite sans avoir de diminution de la résistance mécanique du système ciment alumineux-fumée de silice. C'est pourquoi la combinaison fumée de silice-ester carboxylique acrylique semble être une bonne solution pour produire des mortiers ou des bétons ne subissant pas de perte de résistance à long terme.

---

---

Editorial note Prof, Saveria Monosi and Prof. Marío Collepardi are working at the Department of Materials and Earth Science, University of Ancona, Italy, which is a RILEM Associate Member. Prof. Collepardi is a member of the Board of Advisors for Materials and Structures.     

Analysis of Epstein-Barr virus (EBV) type and variant in spontaneous lymphoblastoid cells and Hu-SCID mouse tumours

Epstein-Barr virus (EBV) type and strain variations were examined using both lymphoblastoid cell lines (LCLs), spontaneously derived in vitro from peripheral blood mononuclear cells (PBMC) of 15 HIV-1-seropositive individuals; and SCID mouse tumours induced by inoculation of PBMC from 11 healthy human donors (Hu-SCID tumours). Polymerase chain reaction (PCR) analysis disclosed that all but one of the 26 EBV + samples harboured EBV nuclear antigen (EBNA) 2 and 3C type A virus. On the other hand, single strand conformation polymorphism (SSCP) analysis using Epstein-Barr encoded RNA (EBER) specific primers detected an AG876-like (type B) band pattern in 21 of the 26 EBV + samples. Three Hu-SCID tumours scored as B95.8-like (type A), and two showed neither a type A nor a type B SSCP migration pattern. Sequence analysis of the amplified EBER fragments confirmed the PCR-SSCP findings; moreover, additional mutations were present not only in the two EBV + samples with anomalous SSCP pattern, but also in two other samples with a standard SSCP profile. Thus, EBER analysis did not correlate with EBNA typing, and appeared to be unsuitable for EBV type assessment. Latent membrane protein (LMP) analysis disclosed, on the whole, sever size variants: as expected, the differences were due to the variable numbers of a 33-bp repeat in the amplified fragment, as assessed by direct sequencing. The broader variability detected by LMP analysis should prove more useful than typing for assessing the presence of single and/or mixed variants resulting from EBV reactivation and/or reinfection.     

Hot-spot detection and characterization of strombolian activity from MODIS infrared data

Identifying and characterizing strombolian activity from space is a challenging task for satellite-based infrared systems. Stromboli volcano is a natural laboratory that offers a unique opportunity for refining thermal remote-sensing applications that involve transient phenomena and small to moderate hot-spots. A new simple and fast algorithm gave us the opportunity to revisit the MODIS-derived thermal output at Stromboli volcano over the last 13 years. The new algorithm includes both night-time and daytime data and shows high performance with the detection of small-amplitude thermal anomalies (<1 MW), as well as a low occurrence of false alerts (<4%). Here, we show that the statistical distribution of volcanic radiative power (VRP; in Watts) is consistent with the detection of variable activity regimes that we subdivided into five levels of thermal activity: Very Low (VRP < 1 MW), Low (1 MW < VRP < 10 MW), Moderate (10 MW < VRP < 100 MW), High (100 MW < VRP < 1000 MW), and Very High (VRP > 1000 MW). The ‘Low’ and ‘Moderate’ thermal levels are associated with strombolian activity and reflect fluctuations of the magma level within the conduit feeding the activity at the surface. The ‘High’ level of thermal output represents the bulk thermal emissions during periods of effusive activity. The highest level (‘Very High’) was reached only during the onset of flank eruptions (28 December 2002 and 27 February 2007). We found that the retrieved thermal regimes are in general agreement with the explosive levels evaluated at Stromboli since 2005, and their correlation has been shown to be dependent on the observed activity (i.e. eruption onset, lateral flank effusion, summit overflows, strombolian activity). Our results suggest that remotely sensed thermal data provide a reliable tool for monitoring volcanic activity at Stromboli volcano.     

Time dependence at 600 and 650° C of M23C6 precipitate composition in AlSl 304 stainless steel

The composition of M₂₃C₆ precipitates in thermally treated AlSl 304 stainless steel was investigated as a function of ageing time at T=600 and 650° C using X-ray fluorescence induced by electron bombardment. With increasing ageing time, it appears that the M₂₃C₆ precipitates become progressively enriched in Cr and depleted in Fe. However, a tendency towards saturation appears, the Cr content being higher at T=650° C.     

Adsorption with axial diffusion in deep beds

Breakthrough behavior is analyzed for adsorption in deep beds with axial diffusion, assuming that a constant pattern wave has developed upstream of the bed outlet. Fluid-solid equilibria are described by both Langmuir and Freundlich isotherms. Breakthrough curves are shown to be much sharper than corresponding constant pattern profiles, especially for very favorable isotherms, as the result of a change in the velocity of the fluid-phase concentration wave during breakthrough. In an appendix, a brief derivation is given of the proper boundary condition for the outlet of a fixed-bed adsorber.     

Mass transfer to volumetric electrodes with two-phase flow

Experimental studies of mass transfer were conducted in stacked screens with a gas-liquid mixture flowing through the bed. Depending on the gas and liquid flow rates and on the geometric characteristics of the screens, different flow regimes are obtained. In the heterogeneous flow regime the gas phase controls mass transfer, meanwhile in the transition and bubbling flow regimes the influence of the liquid flow prevails. Appropriate dimensionless groups correlate the mass transfer coefficients with the pertinent variables for the different regimes.Nomenclature A electrode area (cm²) - A ₁ surface area of one screen (cm²) - c _o bulk concentration (mol cm^–3) - D diffusivity (cm²s^–1) - d particle or wire diameter (cm) - F Faraday's constant - i limiting current (A) - k mass transfer coefficient (cm s^–1) - N distance between wires (cm) - Re _g Reynolds number for gas flow,Re _g=u _g R _h v _g ^–1 - Ré _g Reynolds number for gas flow,Re ₁=u ₁ R _h v ₁ ^–1 - Re ₁ Reynolds number for liquid flow,Re' ₁=u ₁ dv ₁ ^–1 - Ré ₁ Reynolds number for liquid flowRe ₁=u ₁ R _h v ₁ ^–1 - R _h hydraulic radius of screen bed (cm) - S _c Schmidt number,Sc=v ₁ D ^–1 - Sh Sherwood number,Sh=kdD ^–1 - Sh ₀ Sherwood number without gas,Sh ₀ =kdD ^–1 - u _g superficial gas velocity (cm s^–1) - u ₁ superficial liquid velocity (cm s^–1) - screen thickness (cm) - porosity - v kinematic viscosity (cm²s^–1) - specific area (cm^–1)     

Isotactic polypropylene/EPDM blends: Effect of testing temperature and rubber content on fracture

Charpy impact tests in the temperature range ?100 to +20° C have been carried out on two isotactic polypropylenes (PP) having different molecular weight and their blends containing as rubbery phase an ethylene-propylene-diene terpolymer (EPDM). For fractures of brittle nature the impact data were analysed in terms of the linear elastic fracture mechanics andK _c andG _c were determined. This behaviour was observed for the homopolymers over the temperature range investigated, and for the blends only up to ?20° C. At higher temperatures such materials showed fracture of a semiductile type with visible evidence of craze whitening around the crack tip, followed by brittle type fracture. In this case the results were analysed in terms of a ductile contribution (energy required to form the crazed area) and of a brittle one (relative to the crack propagation area) from whichG _c could be derived according to a procedure proposed in the literature. Tentative interpretations of the results also on a molecular and structural basis have been given. A critical discussion of the elaboration of the semiductile fracture data proposed in the literature has also been provided.