A role for growth hormone and prolactin in leukaemia and lymphoma?

Growth hormone (GH) and prolactin (PRL) quality as lymphohaemopoietic growth and differentiation factors, and so does insulin-like growth factor (IGF)-I, which mediates many of GH activities. Although there is only limited evidence that endocrine, paracrine or autocrine GH or PRL play a role in human leukaemia and lymphoma, the expression of these factors or their receptors may have diagnostic or therapeutic implications. Indeed, the participation of GH, PRL or IGF-I in the development or progression of certain haematological malignancies or to the antitumour immune response has been documented. Examples discussed in this review include a rat lymphoma in which the PRL receptor acts as an oncogene; the rat Nb2 lymphoma, which is dependent on PRL for growth; and experiments showing that PRL stimulates natural killer cell activity and the development of lymphokine-activated killer cells.     

Oxidation of a Mn-Cr austenitic steel during creep testing and its interaction with the fracture

The interaction between oxidation and creep rupture was studied in a 17 Mn-10 Cr austenitic steel, of interest as structural material for the internal components of fusion reactors. The observation of the creep specimens tested in air at temperatures ranging from 773 to 973 K revealed the presence of an adherent oxide scale and of a ferritic phase underneath, which forms as a consequence of the Mn depletion of the austenitic matrix. The microstructure of the two layers was investigated by optical microscopy, SEM, X-ray diffraction, EDS and magnetic permeability measurements. The scale has a complex structure, being composed mainly of manganese oxide. The ferritic layer is completely recrystallized and does not present grain boundary precipitates as the austenitic phase does. The effect of the surface modification on the creep rupture process is discussed in the light of a recent model of deformation-oxidation interaction.     

Model‐driven design of collaborative Web applications

This paper introduces a model‐driven approach to the design of collaborative Web‐based applications, i.e. applications in which several users play different roles, in a collaborative way, to pursue a specific goal. The paper illustrates a conference management application (CMA), whose main requirements include: (i) the management of users profiles and access rights based on the role played by users during the conference life cycle; (ii) the delivery of information and services to individual users; (iii) the management of the sequence of activities that lead to the achievement of a common goal. The presented approach is based on WebML, a conceptual modelling language for the Web. The paper also highlights some general properties—as understood by the practical experience of CMA development—that a Web modelling language should feature in order to fully support the development of collaborative applications. Copyright © 2003 John Wiley & Sons, Ltd.     

Optimization of properties and operating parameters of a passive DMFC mini-stack at ambient temperature

An investigation of properties and operating parameters of a passive DMFC monopolar mini-stack, such as catalyst loading and methanol concentration, was carried out. From this analysis, it was derived that a proper Pt loading is necessary to achieve the best compromise between electrode thickness and number of catalytic sites for the anode and cathode reactions to occur at suitable rates. Methanol concentrations ranging from 1 M up to 10 M and an air-breathing operation mode were investigated. A maximum power of 225 mW was obtained at ambient conditions for a three-cell stack, with an active single cell area of 4 cm², corresponding to a power density of about 20 mW cm⁻².     

Analysis of polyphosphates in fish and shrimps tissues by two different ion chromatography methods: implications on false-negative and -positive findings.

Inorganic polyphosphates (di-, tri- and higher polyphosphates) can be used to treat fish, fish fillets and shrimps in order to improve their water-binding capacity. The practical relevance of this treatment is a significant gain of weight caused by the retention/uptake of water and natural juice into the fish tissues. This practice is legal; however, the use of phosphates has to be declared. The routine control testing of fish for the presence of polyphosphates, produced some results that were difficult to explain. One of the two analytical methods used determined low diphosphate concentrations in a number of untreated samples, while the other ion chromatography (IC) method did not detect them. This initiated a number of investigations: results showed that polyphosphates in fish and shrimps tissue undergo a rapid enzymatic degradation, producing the ubiquitous orthophosphate. This led to the conclusion that sensitive analytical methods are required in order to detect previous polyphosphate treatment of a sample. The polyphosphate concentrations detected by one of the analytical methods could not be explained by the degradation of endogenous high-energy nucleotides like ATP into diphosphate, but by a coeluting compound. Further investigations by LC-MS-MS proved that the substance responsible for the observed peak was inosine monophsosphate (IMP) and not as thought the inorganic diphosphate. The method producing the false-positive result was modified and both methods were ultimately able to detect polyphosphates well separated from natural nucleotides. Polyphosphates could no longer be detected (<0.5 mg kg-1) after modification of the analytical methodology. The relevance of these findings lies in the fact that similar analytical methods are employed in various control laboratories, which might lead to false interpretation of measurements.     

Effects of some antineoplastic drugs (vincristine, doxorubicin and epirubicin) on human platelet aggregation

The effects of some antineoplastic drugs (vincristine, doxorubicin and epirubicin) on collagen- and ADP-induced human platelet aggregation are investigated. Platelet rich plasma (PRP) and platelet poor plasma (PPP) from healthy male and female donors were used. The PRP was adjusted with analogous PPP to 300,000 platelets/microliters. Platelet aggregation was studied according to Born's turbidimetric technique using an Aggrecorder II PA 3220 with collagen at a concentration of 10 micrograms/ml and ADP at a concentration of 30 microM. Vincristine, doxorubicin and epirubicin significantly (p < 0.01) inhibited collagen- and ADP-induced platelet aggregation. The vincristine induced inhibition was higher than that induced by doxorubicin or epirubicin. The effects of doxorubicin and epirubicin were more intense on ADP-induced platelet aggregation than on the collagen induced one. Moreover, the doxorubicin inhibition of ADP-induced platelet aggregation was greater than the epirubicin one. In conclusion, our study shows that vincristine, doxorubicin and epirubicin inhibit human platelet aggregation. The present results may improve the therapeutic use of these drugs since it has been clearly shown that drugs with antiplatelet activity could block metastases.     

Statistical treatment of the evolution of the principal states ofpolarization in single-mode fibers

A simple relationship is found for the evolution of the principal states of polarization (PSPs) and their differential group delay in fiber links. A simple expression is found, using the relationship, for the probability of the differential group delay (DGD), considering the evolution of the PSPs as a Brownian motion. The theory has been verified experimentally on an optical cable composed of 12 single-mode, shifted-dispersion fibers 2.2-km long. The results show that the DGD grows as the square root of the length when the length of the fiber is far larger than the correlation length of the perturbation. The measured value of DGD can vary substantially in two fibers belonging to the same ensemble, and in the same fiber, considering two frequencies differing by more than 5 nm     

Dichroism effect on polarization-modulated optical systems usingStokes parameters coherent detection

Antipodal Stokes parameters shift keying (ASPSK) performance is analyzed in the presence of dichroism. Two different approximate analytical approaches are used, and the obtained results are in good agreement. In the presence of dichroism not only does a sensitivity penalty arise, but also the system performance is not independent of the received state of polarization. However, these effect are not very relevant even in situations in which a large amount of dichroism is present, such as when inline amplifiers are present, so that the system shows a good tolerance with respect to dichroism. The results confirm the feasibility of ASPSK for point-to-point and multipoint systems even in conjunction with emerging optical technologies such as optical amplifiers and nonlinear couplers     

Laser processing of TiSi2 and CoSi2 thin films on silicon (100) substrates

We have investigated the formation of TiSi₂ and CoSi₂ thin films on Si(100) substrates using laser (wave length 248 nm, pulse duration 40 ns and repetition rate 5 Hz) physical vapor deposition (LPVD). The films were deposited from solid targets of TiSi₂ and CoSi₂ in vacuum with the substrate temperature optimized at 600° C. The films were characterized using x-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and four point probe ac resistivity. The films were found to be polycrystalline with a texture. The room temperature resistivity was found to be 16 μΩ-@#@ cm and 23 μΩ-cm for TiSi₂ and CoSi₂ films, respectively. We optimized the processing parameters so as to get particulate free surface. TEM results show that the silicide/silicon interface is quite smooth and there is no perceptible interdiffusion across the interface.