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We present the development and characterization of a high-stability, multi-material, multi-thickness tape-drive target for laser-driven acceleration at repetition rates of up to 100 Hz. The tape surface position was measured to be stable on the sub-micrometre scale, compatible with the high-numerical aperture focusing geometries required to achieve relativistic intensity interactions with the pulse energy available in current multi-Hz and near-future higher repetition-rate lasers (>kHz). Long-term drift was characterized at 100 Hz demonstrating suitability for operation over extended periods. The target was continuously operated at up to 5 Hz in a recent experiment for 70,000 shots without intervention by the experimental team, with the exception of tape replacement, producing the largest data-set of relativistically intense laser--solid foil measurements to date. This tape drive provides robust targetry for the generation and study of high-repetition-rate ion beams using next-generation high-power laser systems, also enabling wider applications of laser-driven proton sources. [ABSTRACT FROM AUTHOR]

A machine learning model was created to predict the electron spectrum generated by a GeV-class laser wakefield accelerator. The model was constructed from variational convolutional neural networks, which mapped the results of secondary laser and plasma diagnostics to the generated electron spectrum. An ensemble of trained networks was used to predict the electron spectrum and to provide an estimation of the uncertainty of that prediction. It is anticipated that this approach will be useful for inferring the electron spectrum prior to undergoing any process that can alter or destroy the beam. In addition, the model provides insight into the scaling of electron beam properties due to stochastic fluctuations in the laser energy and plasma electron density. [ABSTRACT FROM AUTHOR]

The interaction of relativistically intense lasers with opaque targets represents a highly non-linear, multi-dimensional parameter space. This limits the utility of sequential 1D scanning of experimental parameters for the optimization of secondary radiation, although to-date this has been the accepted methodology due to low data acquisition rates. High repetition-rate (HRR) lasers augmented by machine learning present a valuable opportunity for efficient source optimization. Here, an automated, HRR-compatible system produced high-fidelity parameter scans, revealing the influence of laser intensity on target pre-heating and proton generation. A closed-loop Bayesian optimization of maximum proton energy, through control of the laser wavefront and target position, produced proton beams with equivalent maximum energy to manually optimized laser pulses but using only 60% of the laser energy. This demonstration of automated optimization of laser-driven proton beams is a crucial step towards deeper physical insight and the construction of future radiation sources. [ABSTRACT FROM AUTHOR]

We report on the characterisation of an x-ray source, generated by a laser-driven plasma wakefield accelerator. The spectrum of the optimised source was consistent with an on-axis synchrotron spectrum with a critical energy of keV and the number of photons per pulse generated above 1 keV was calculated to be. The x-ray beam was used to image a resolution grid placed 37 cm from the source, which gave a measured spatial resolution of 4 µm × 5 µm. The inferred emission region had a radius and length of 0.5 ± 0.2 µm and 3.2 ± 0.9 mm respectively. It was also observed that laser damage to the exit aperture of the gas cell led to a reduction in the accelerated electron beam charge and a corresponding reduction in x-ray flux due to the change in the plasma density profile. [ABSTRACT FROM AUTHOR]

We address the scattering of a high energy laser pulse on a large wavelength acoustic turbulence of relevance for Laser M'egajoule or National Ignition Facility-class experiments. Both kinetic and hydrodynamic frameworks are adopted and combined with a linearized description of the laser propagation. The resulting dispersion relations display important kinetic contributions to the growth of the forward Brillouin instability. Moreover, proof is made that the spatial incoherence often used in high energy laser facilities is, for cold enough plasmas or in the multi-ion species case, not enough to reach full control of the laser filamentation. Comparisons with experimental results and dedicated hydrodynamic simulations confirm our results. The derived dispersion relations present new tools for assessing the propagation quality and energy deposition region of high energy laser pulses. They also underline the importance of accounting for kinetic effects, even in the millimeter and nanosecond scale of many inertial confinement fusion or high-energy-density experiments. [ABSTRACT FROM AUTHOR]

Laser wakefield accelerators promise to revolutionize many areas of accelerator science. However, one of the greatest challenges to their widespread adoption is the difficulty in control and optimization of the accelerator outputs due to coupling between input parameters and the dynamic evolution of the accelerating structure. Here, we use machine learning techniques to automate a 100 MeV-scale accelerator, which optimized its outputs by simultaneously varying up to six parameters including the spectral and spatial phase of the laser and the plasma density and length. Most notably, the model built by the algorithm enabled optimization of the laser evolution that might otherwise have been missed in single-variable scans. Subtle tuning of the laser pulse shape caused an 80% increase in electron beam charge, despite the pulse length changing by just 1%. Laser wakefield accelerators are compact sources of ultra-relativistic electrons which are highly sensitive to many control parameters. Here the authors present an automated machine learning based method for the efficient multi-dimensional optimization of these plasma-based particle accelerators. [ABSTRACT FROM AUTHOR]

In this article, we showcase the experimental results of methods to produce and characterize orbital angular momentum (OAM) carrying high-power lasers. The OAM pulses were produced on the ASTRA laser of the Central Laser Facility using a continuous spiral phase plate. Three different characterization methods were then used to measure the OAM content of the beam. The methods that were used were a cylindrical lens diagnostic, an interferometric diagnostic, and a projective diagnostic. We further discuss the relative advantages and disadvantages of each method in the context of high-power laser experiments. [ABSTRACT FROM AUTHOR]

The laser driven plasma wakefield accelerator is a very compact source of high energy electrons. When the quasi-monoenergetic beam from these accelerators passes through dense material, high energy bremsstrahlung photons are emitted in a collimated beam with high flux. We show how a source based on this emission process can produce more than 109 photons per pulse with a mean energy of 10 MeV. We present experimental results that show the feasibility of this method of producing high energy photons and compare the experimental results with GEANT4 Montecarlo simulations, which also give the scaling required to evaluate its suitability as method to produce radioisotopes via photo-nuclear reactions or for imaging applications. [ABSTRACT FROM AUTHOR]

We describe how active feedback routines can be applied at a limited repetition rate (5 Hz) to optimize high-power ( > 10 TW ) laser interactions with clustered gases. Optimization of x-ray production from an argon cluster jet, using a genetic algorithm, approximately doubled the measured energy through temporal modification of the 150 mJ driving laser pulse. This approach achieved an increased radiation yield through exploration of a multi-dimensional parameter space, without requiring detailed a priori knowledge of the complex cluster dynamics. The optimized laser pulses exhibited a slow rising edge to the intensity profile, which enhanced the laser energy coupling into the cluster medium, compared to the optimally compressed FWHM pulse (40 fs). Our work suggests that this technique can be more widely utilized for control of intense pulsed secondary radiation from petawatt-class laser systems. [ABSTRACT FROM AUTHOR]

This article concerns validation and verification (V&V) of the open source OpenFOAM incompressible flow solver that is widely used in both research and industry for the simulation of turbulent flows. Its numerical discretization scheme relies on classical finite volumes that are second order in space on regular grids. The solver is benchmarked using a challenging test case for which direct numerical simulation (DNS) reference data exist. The geometrical configuration of this flow is very simple, yet the behavior of the flow is 3D, complex, and unsteady, requiring an accurate flow solver to capture the associated physics. The physical problem addressed here requires huge computational grids. Computations are thus carried using parallel domain decomposition methods on a fairly large number of cores. The validation study performed here is particularly severe as it consists in comparing OpenFOAM results with DNS data obtained using high-order codes. As simulations of turbulent flows require great computational resources, results concerning strong and weak scalability of the OpenFOAM flow solver are also presented. The performances of the code are assessed on two different HPC infrastructures. The experiences carried here show that OpenFOAM scales fairly up to 1000 cores on a Tier-1cluster. The influences of the processor hardware and network topology are also highlighted. This study also provides profiling diagnostics thanks to the Integrated Performance Monitor (IPM). [ABSTRACT FROM AUTHOR]

Candida glabrata has emerged as a major pathogen in invasive candidiasis in recent years. Currently, guidelines for invasive candidiasis treatment recommend fluconazole or an echinocandin as the first-line therapy. Nevertheless, the resistance of Candida glabrata to echinocandin is an emerging problem and has been partly associated with mutations in the FKS1 and FKS2 genes. The Etest® is an appropriate method for determining antifungal susceptibility in emergency routine diagnosis. In this work, we evaluated the reliability of the Etest® in comparison with the two reference broth microdilution methods, Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST), to assess the caspofungin resistance of 193 isolates of Candida glabrata. The interpretation of minimum inhibitory concentration (MIC) values was also discussed according to different breakpoints. Moreover, FKS1 and FKS2 mutations were investigated for isolates with high MICs. Our results showed that the MIC value was similar to the MIC value for each method. The Etest® method showed the lowest MIC values, whereas EUCAST presented the highest. Categorical agreement between the Etest® and CLSI methods was 100 % and 36 % using the breakpoints proposed by Arendrup et al. (Antimicrob Agents Chemother 56(7):3965-3968, ) and Pfaller et al. (Int J Antimicrob Agents 38(1):65-69, ), respectively. Two isolates showed high MIC values with the three methods and both presented FKS2 mutations. A novel FKS2 mutation was also reported for one isolate. Future epidemiological studies should also evaluate the reliability of the Etest® to detect echinocandin resistance, as it remains a routine method. [ABSTRACT FROM AUTHOR]

The generation of GeV-scale electron beams in a gas-filled capillary discharge waveguide with good reproducibility is discussed. Beams of electrons with energies above 900MeV, and with root-mean-square divergences of 3.5 mrad, are observed for a plasma density of 2.2×1018 cm-3 and a peak input laser power of 55TW. The variation of the maximum electron energy with the plasma density is measured and found to agree well with simple models. Injection and acceleration of electrons at the to date lowest plasma density of 3.2×1017 cm-3 are reported. The energy spectra of the generated electron beams exhibit good shot-to-shot reproducibility, with the observed variations attributable to the measured shot-to-shot jitter of the laser parameters. Two methods for correcting the effect of beam pointing variations on the measured energy spectrum are described. [ABSTRACT FROM AUTHOR]

Self-modulated wakefield acceleration was investigated at densities down to ~4 × 1018 cm−3 by propagating the 50 TW 300 fs LULI laser in helium gas jets at lengths up to 1 cm. Long interaction lengths were achieved by closer matching of the initial focal spot size to the matched spot size for these densities. Electrons with energies extending to 180 MeV were observed in broad energy spectra which show some evidence for non-Maxwellian features at high energy. Two-dimensional PIC simulations indicate that the intial laser pulse breaks up into small pulselets that are eventually compressed and focused inside the first few plasma periods, leading to a ‘bubble-like’ acceleration of electron bunches. [ABSTRACT FROM PUBLISHER]

In this paper, we deal with the problem of finding quasi-independent sets in graphs. This problem is formally defined in three versions, which are shown to be polynomially equivalent. The one that looks most general, namely, f- max quasi-independent set, consists of, given a graph and a non-decreasing function f, finding a maximum size subset Q of the vertices of the graph, such that the number of edges in the induced subgraph is less than or equal to f(| Q|). For this problem, we show an exact solution method that runs within time $O^{*}(2^{\frac{d-27/23}{d+1}n})$ on graphs of average degree bounded by d. For the most specifically defined γ- max quasi-independent set and k- max quasi-independent set problems, several results on complexity and approximation are shown, and greedy algorithms are proposed, analyzed and tested. [ABSTRACT FROM AUTHOR]

Electrostatic (E) fields associated with the interaction of a well-controlled, high-power, nanosecond laser pulse with an underdense plasma are diagnosed by proton radiography. Using a current three-dimensional wave propagation code equipped with nonlinear and nonlocal hydrodynamics, we can model the measured E-fields that are driven by the laser ponderomotive force in the region where the laser undergoes filamentation. However, strong fields of up to 110 MV/m measured in the first millimeter of propagation cannot be reproduced in the simulations. This could point to the presence of unexpected strong thermal electron pressure gradients possibly linked to ion acoustic turbulence, thus emphasizing the need for the development of full kinetic collisional simulations in order to properly model laser-plasma interaction in these strongly nonlinear conditions. [ABSTRACT FROM AUTHOR]

Attraction and fusion between co-propagating light beams, mutually coherent or not, can take place in nonlinear media as a result of the beam power modifying the refractive index of the medium. In the context of high-power light beams, induced modifications of the beam patterns could potentially impact many topics, including long-range laser propagation, the study of astrophysical colliding blast waves and inertial confinement fusion. Here, through experiments and simulations, we show that in a fully ionized plasma, which is a nonlinear medium, beam merging can take place for high-power and mutually incoherent beams that are initially separated by several beam diameters. This is in contrast to the usual assumption that this type of interaction is limited to beams separated by only one beam diameter. This effect, which is orders of magnitude more significant than Kerr-like nonlinearity in gases, demonstrates the importance of potential cross-talk amongst multiple beams in plasma. [ABSTRACT FROM AUTHOR]

Objectives The aim of the study was to describe a new evolutionary form of visceral leishmaniasis observed in immunocompromised patients. Methods We carried out long-term clinical and biological follow-up of 10 HIV-1/Leishmania-coinfected patients presenting numerous secondary visceral leishmaniasis episodes despite treatment, with the follow-up time ranging from 0.5 to 10 years. Results Analysis of polymerase chain reaction (PCR) and blood culture results demonstrated continuous multiplication and circulation of parasites despite treatment, both during asymptomatic periods and during secondary visceral leishmaniasis episodes. This condition may be termed 'chronic' because of the presence of relapses over a period of several years and 'active' because of the continuous blood circulation of the parasite. Conclusion We wish to define 'active chronic visceral leishmaniasis' as a novel nosological entity observed in HIV-1/Leishmania-coinfected patients. [ABSTRACT FROM AUTHOR]

The aim of the ArDM project is the development and operation of a one ton double-phase liquid argon detector for direct Dark Matter searches. The detector measures both the scintillation light and the ionization charge from ionizing radiation using two independent readout systems. This paper briefly describes the detector concept and presents preliminary results from the ArDM R&D program, including a 31 prototype developed to test the charge readout system. [ABSTRACT FROM AUTHOR]

High-energy electrons can be produced in interactions of intense, ultra-short laser pulses with plasmas. Experiments conducted in the regime of moderate laser power (a few terawatts [TW]) are attracting increasing attention for their possibility of optimizing the acceleration process. Here we report the successful production of several-MeV electron bunches in interactions of femtosecond laser pulses from a 10 TW tabletop laser with supersonic gas-jets. The laser-plasma interaction and the obtained electron bunches have been characterized in detail, and conditions for stable and reproducible acceleration have been found. The accelerated electron bunches have been characterized by means of the measurement of the induced photo-activation of a gold sample via bremsstrahlung-generation of photons with suitable energy. The obtained result opens up a wide range of possible applications of the compact electron source for the concerns of nuclear physics studies. Some of them are briefly considered in this paper. [ABSTRACT FROM AUTHOR]

The role of plasma channels as waveguides for laser-wakefield accelerators is discussed in terms of the results of experiments performed with the Astra-Gemini laser, numerical simulations using the code WAKE, and the theory of self-focusing and self-guiding of intense laser beams. It is found that at a given electron density, electron beams can be accelerated using lower laser powers in a waveguide structure than in a gas-jet or cell. The transition between relativistically self-guided and channel-assisted guiding is seen in the simulations and in the behaviour of the production of electron beams. We also show that by improving the quality of the driving laser beam the threshold laser energy required to produce electron beams can be reduced by a factor of almost 2. The use of an aperture allows the production of a quasi-monoenergetic electron beam of energy 520MeV with an input laser power of only 30TW. [ABSTRACT FROM AUTHOR]

We demonstrate widely tunable and broadband single shot electro-optic detection of THz waveforms with a linear response to the electric field over a wide range. The THz field is encoded to the temporally dispersed spectrum of a supercontinuum whose polarization state is analyzed in balanced detection. With the probe bandwidth corresponding to a Fourier Transform-limited duration below 5 fs, the time window can easily be adjusted in the fs to 100 ps range to be several times longer than the THz pulse without signal distortion. Thanks to a laser fluctuation-free design, the phase retardation (Γ) is measured under shot noise limited conditions with a rms noise below 0.005 over the whole spectral (i.e., temporal) window. The method allows the direct determination of the absolute amplitude of the THz field for the first time in a single shot EO-experiment. The performance of the diagnostic can be achieved with state-of-the-art fs to ps laser sources. [ABSTRACT FROM AUTHOR]

The present study is based on cases of sheet rupture, which occurred on deep drawn components produced in a workshop of one company during deep drawing operations. A characterisation of material behaviour in deep drawing is proposed to define the limits imposed to the forming of sheets by the development of a zone of localised necking. First, tension tests are carried out to determine the characteristics of the material, i.e., the anisotropy coefficient and the hardening law. Then, deep drawing tests of the Marciniak type are carried out to determine the Forming Limit Curve (FLC) of the material by means of the method of image correlation using specific software. Knowing the properties of the material and the limits of deformation which define the occurrence of necking, the problem of sheet rupture during material forming will be reduced. [ABSTRACT FROM AUTHOR]

The strain-hardening behavior and plastic anisotropy of a steel sheet of deep drawing quality has been characterized in uniaxial tension tests, and several forming tests have been performed to determine the Forming Limit Curve, the Limiting Dome Height in the hemispherical punch test and the height of ears in the cup drawing test. The experiments are compared with finite element predictions obtained with a flexible model for orthotropic plasticity, which allows us to discuss the importance of material parameters for obtaining reliable predictions by means of the numerical simulation. [ABSTRACT FROM AUTHOR]

X-ray spectroscopic diagnostics of laser-cluster interaction at the stage of nonadiabatic scattering of clusters and formation of a spatially uniform plasma channel has been performed. The experimental investigations have been carried out on a Ti:Sa laser setup with a pulse duration of about 65 fs and an energy up to 600 mJ. It has been shown that, within 10 ps from the beginning of a laser femtosecond pulse, the laser-cluster interaction forms a uniform plasma channel with a length of 0.4 to 1 mm with the parameters N e ∼ 1019−1020 cm−3 and T e ∼ 100 eV. [ABSTRACT FROM AUTHOR]

: To evaluate the efficacy of early interferon α-2b in non-post-transfusion acute hepatitis C virus: a prospective study with historical comparison. : Group A: 28 patients prospectively treated for acute hepatitis C virus with daily regimen of interferon 5 million units for 2 months. Group B: historical series of 16 patients with untreated acute hepatitis C virus. : There was no significant difference between the two groups with regard to gender, age, icterus, alanine aminotransferase, or genotypes. In group B, hepatitis spontaneously resolved in three of 16 (19%) patients (follow-up 1–7 years). In group A, 21 of 25 patients became sustained viral responders (75%; P = 0.0003 vs. group B). Factors include not predictive of sustained viral response: age, gender, sources of infection, presence of icterus, alanine aminotransferase peak, bilirubin peak, incubation period, presence of hepatitis C virus antibodies at presentation, or genotypes. The time from presentation to the start of therapy was, however, significantly shorter in sustained viral responders (43 ± 31 days) than in relapsers or non-responders (88 ± 52 days) ( P = 0.016). : Early treatment of acute hepatitis C virus with interferon prevents chronicity. A short waiting time from presentation to treatment appears as the most relevant predictive factor for sustained response. [ABSTRACT FROM AUTHOR]

Objective: To describe the changes in demographics, antidiabetic treatment, and glycemic control among the prevalent U.S. adult diagnosed type 2 diabetes population between the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and the initial release of NHANES 1999-2000.Research Design and Methods: The study population was derived from NHANES III (n = 1,215) and NHANES 1999-2000 (n = 372) subjects who reported a diagnosis of type 2 diabetes with available data on diabetes medication and HbA(1c). Four therapeutic regimens were defined: diet only, insulin only, oral antidiabetic drugs (OADs) only, or OADs plus insulin. Multiple logistic regression was used to examine changes in antidiabetic regimens and glycemic control rates over time, adjusted for demographic and clinical risk factors. The outcome measure for glycemic control was HbA(1c). Glycemic control rates were defined as the proportion of type 2 diabetic patients with HbA(1c) level <7%.Results: Dietary treatment in individuals with diabetes decreased as the sole therapy from 27.4 to 20.2% between the surveys. Insulin use also decreased from 24.2 to 16.4%, while those on OADs only increased from 45.4 to 52.5%. Combination of OADs and insulin increased from 3.1 to 11.0%. Glycemic control rates declined from 44.5% in NHANES III (1988-1994) to 35.8% in NHANES 1999-2000.Conclusions: Treatment regimens among U.S. adults diagnosed with type 2 diabetes have changed substantially over the past 10 years. However, a decrease in glycemic control rates was also observed during this time period. This trend may contribute to increased rates of macrovascular and microvascular diabetic complications, which may impact health care costs. Our data support the public health message of implementation of early, aggressive management of diabetes. [ABSTRACT FROM AUTHOR]

The standard treatment for patients with chronic hepatitis C is a 6–12-month combination therapy with interferon alpha and ribavirin. Induction treatment could result in a faster early decline of the hepatitis C virus (HCV) load and a better response rate. Naive chronically infected HCV patients ( n = 454) were randomized into two arms to receive either induction treatment with interferon alpha 2b 5 million units (MU) subcutaneously (s.c.) daily during a period of 8 weeks (arm A); or treatment with interferon alpha 2b 5 MU s.c. three times a week (TIW) for a period of 8 weeks (arm B). After week 8, interferon treatment in both arms was 3 MU s.c. TIW for a total period of 12 months. In both arms, ribavirin (1000–1200 mg orally per day) was added at week 4. Induction treatment resulted in a higher virological response at week 8 of treatment (66% vs 47%; P < 0.01). However, response at the end of treatment and at 6 months follow-up was not different (53% vs 50%, 41% vs 33%). The occurrence of adverse events and the drop-out rate were similar in both arms. Although an early virological response is observed more frequently in the induction treatment, end of treatment response and sustained responses did not differ. [ABSTRACT FROM AUTHOR]

A study of ellipsoids (EL) in the human spleen was done on 25 surgically resected specimens in order to assess the number of EL, their structure, the nature of the cuff cells and the problem of lymphocyte traffic through their wall. The results show that an average spleen of 200 g contains 1.6 × 10 EL. They are localized in a constant segment of the vascular tree, just at the transition of the penicillary arterioles into capillaries and they consist of a capillary (not an arteriole) surrounded by a cuff of cells. These cells are neither endothelial nor smooth muscle cells, display lysosomal activity and are considered as fixed specialized pericapillary cells capable of cytoplasmic expansion. Since their number is inconstant in different individuals and in different species they are considered to be dynamic histological structures. Because of the constant presence of lymphocytes in their walls we consider the EL to be a transit system for lymphocytes and the splenic equivalent of the high endothelial venules in the lymph nodes. [ABSTRACT FROM AUTHOR]

Non-lymphoid haematopoiesis in the thymus was studied in 33 cases ranging from 14 weeks gestation up to 15 months postnatally. All thymuses displayed focally granulopoiesis in the connective tissue septa and in the lymphoid tissue, where it was localized in the peripheral cortex and at the cortico-medullary junction. Within the lymphoid tissue the granulocytic series showed many precursor cells with large rounded nuclei. Their origin could only be identified by the naphtol AS D chloroacetate esterase stain. In cases with thymic atrophy these precursor cells were present in relatively large numbers. Within the connective tissue septa many granulocytes with nuclear segmentation were intermingled with precursor cells. The erythroid series were detected with an immunohistochemical method for demonstration of haemoglobin. The positively stained nucleated cells occurred mainly in nests mostly localized in the peripheral cortex. These precursor cells were usually found in different places from the granulopoietic cells. No megakaryocytes were found. With appropriate techniques non-lymphoid haematopoiesis can be demonstrated in the developing thymus and must be considered as an expression of normal growth. [ABSTRACT FROM AUTHOR]

The relationship between mononuclear, multinucleated and multilobated Sternberg-Reed cells was studied by reconstructions done on serial sections 1-2 μm thick. The 21 cells so studied showed the following combinations: 7 were binucleated, but two nuclei were composed of two parts at certain levels; these nuclei we propose to call composite. 8 cells were mononuclear and had composite nuclei and 6 cells were mononuclear and had single nuclei. [ABSTRACT FROM AUTHOR]

Variceal haemorrhage in cirrhotic patients carries a high early mortality even when balloon tamponade or emergency sclerotherapy are applied. The aim of this study to identify patients dying within six weeks of their first variceal haemorrhage. One hundred and twenty one patients with parenchymal cirrhosis presenting with the first variceal bleeding episode between June 1983 and December 1988 were studied. Nineteen patients were excluded for various reasons. Emergency sclerotherapy was carried out in cases of active bleeding or where there were endoscopic signs of recent bleeding, and then regularly repeated afterwards. Of the 24 variables studied and included in a multivariate analysis using a logistic regression model, three had an independent prognostic value: encephalopathy, prothrombin time, and the number of blood units transfused within the 72 hours of time zero. The subsequent regression equation was able to predict 89% of the patients who will die and 97% of the patients who will still be alive six weeks after their first variceal haemorrhage treated by sclerotherapy. Pugh score was less discriminatory than these last three variables in terms of accuracy of adjustment, goodness of fit to the model, receiver operating characteristic curves, and percentage correct prediction. To measure the accuracy of the prediction rule, our model was applied to another series of 28 cirrhotic patients admitted with their first variceal bleeding during the next period (January 1989 to May 1990). Death and survival were correctly predicted in respectively 82% and 94% of the cases. The use of this score is recommended for the selection of patients with high early mortality after variceal bleeding despite sclerotherapy, and for the design of new therapeutic trials. [ABSTRACT FROM PUBLISHER]

A 39-year-old Ugandan student is described presenting with general malaise, fever and a pulmonary infiltrate. Open lung biopsy showing infarction and positive ANCA lead to a diagnosis of Wegener's granulomatosis and a treatment with immunosuppressive drugs was instituted. Five weeks after admission, however, sputum cultures turned out to be positive for Mycobacterium tuberculosis. The importance of ANCAinterpretation and the possibility of false positive results is discussed. [ABSTRACT FROM AUTHOR]