Advanced spectroscopic investigation of colour centres in LiF crystals irradiated with monochromatic hard x-rays

Nominally-pure lithium fluoride (LiF) crystals were irradiated with monochromatic hard x-rays of energy 5, 7, 9 and 12 keV at the METROLOGIE beamline of the SOLEIL synchrotron facility, in order to understand the role of the selected x-ray energy on their visible photoluminescence (PL) response, which is used for high spatial resolution 2D x-ray imaging detectors characterized by a wide dynamic range. At the energies of 7 and 12 keV the irradiations were performed at five different doses corresponding to five uniformly irradiated areas, while at 5 and 9 keV only two irradiations at two different doses were carried out. The doses were planned in a range between 4 and 1.4 × 103Gy (10.5 mJ cm-3to 3.7 J cm-3), depending on the x-ray energy. After irradiation at the energies of 7 and 12 keV, the spectrally-integrated visible PL intensity of the F2and F3+colour centres (CCs) generated in the LiF crystals, carefully measured by fluorescence microscopy under blue excitation, exhibits a linear dependence on the irradiation dose in the investigated dose range. This linear behaviour was confirmed by the optical absorption spectra of the irradiated spots, which shows a similar linear behaviour for both the F2and F3+CCs, as derived from their overlapping absorption band at around 450 nm. At the highest x-ray energy, the average concentrations of the radiation-induced F, F2and F3+CCs were also estimated. The volume distributions of F2defects in the crystals irradiated with 5 and 9 keV x-rays were reconstructed in 3D by measuring their PL signal using a confocal laser scanning microscope operating in fluorescence mode. On-going investigations are focusing on the results obtained through thisz-scanning technique to explore the potential impact of absorption effects at the excitation laser wavelength.

Exploring the Atwood-number dependence of the highly nonlinear Rayleigh-Taylor instability regime in high-energy-density conditions

We experimentally study the late-time, highly nonlinear regime of the Rayleigh-Taylor instability in a decelerating phase. A series of laser-driven experiments is performed on the LULI2000 laser, in which the initial Atwood number is varied by adjusting the decelerating medium density. The high-power laser is used in a direct drive configuration to put into motion a solid target. Its rear side, which initially possesses a two-dimensional machined sinusoidal perturbations, expands and decelerates into a foam leading to a Rayleigh-Taylor unstable situation. The interface position and morphology are measured by time-resolved x-ray radiography. We develop a simple Atwood-dependent model describing the motion of the decelerating interface, from which its acceleration history is obtained. The measured amplitude of the instability, or mixing zone width, is then compared with late-time acceleration-dependent Rayleigh-Taylor instability models. The shortcomings of this classical model, when applied to high-energy-density conditions, are shown. This calls into question their uses for systems, where a shock wave is present, such as those found in laboratory astrophysics or in inertial confinement fusion.

Micron-scale phenomena observed in a turbulent laser-produced plasma

Turbulence is ubiquitous in the universe and in fluid dynamics. It influences a wide range of high energy density systems, from inertial confinement fusion to astrophysical-object evolution. Understanding this phenomenon is crucial, however, due to limitations in experimental and numerical methods in plasma systems, a complete description of the turbulent spectrum is still lacking. Here, we present the measurement of a turbulent spectrum down to micron scale in a laser-plasma experiment. We use an experimental platform, which couples a high power optical laser, an x-ray free-electron laser and a lithium fluoride crystal, to study the dynamics of a plasma flow with micrometric resolution (~1μm) over a large field of view (>1 mm²). After the evolution of a Rayleigh–Taylor unstable system, we obtain spectra, which are overall consistent with existing turbulent theory, but present unexpected features. This work paves the way towards a better understanding of numerous systems, as it allows the direct comparison of experimental results, theory and numerical simulations.

Turbulence effects explored use macroscale systems in general. Here the authors generate a turbulent plasma using laser irradiation of a solid target and study the dynamics of the plasma flow at the micron-scale by using scattering of an XFEL beam.

Rayleigh-Taylor instability experiments on the LULI2000 laser in scaled conditions for young supernova remnants

We describe a platform developed on the LULI2000 laser facility to investigate the evolution of Rayleigh-Taylor instability (RTI) in scaled conditions relevant to young supernova remnants (SNRs) up to 200 years. An RT unstable interface is imaged with a short-pulse laser-driven (PICO2000) x-ray source, providing an unprecedented simultaneous high spatial (24μm) and temporal (10 ps) resolution. This experiment provides relevant data to compare with astrophysical codes, as observational data on the development of RTI at the early stage of the SNR expansion are missing. A comparison is also performed with FLASH radiative magnetohydrodynamic simulations.

Characterization of high spatial resolution lithium fluoride X-ray detectors

The response of lithium fluoride (LiF) crystal detectors to monochromatic X-rays is measured in the multi-kilo-electron-volt range. This response, as a function of the X-ray dose, is independent of photon energy with no saturation level found. The response, as a function of the incident energy flux, is found to increase for photons of lower energy due to the differing attenuation lengths of X-ray photons within the crystal. Small differences are seen between different confocal microscopes used to scan the data, suggesting the need for absolute calibration. The spatial resolution of the LiF is also measured (1.19-1.36 μm) and is found to be independent of incident photon energy. Finally, a photometric study is performed in order to assess the feasibility of using these detectors at current X-ray free electron laser and laser facilities worldwide.

Laboratory study of stationary accretion shock relevant to astrophysical systems

Accretion processes play a crucial role in a wide variety of astrophysical systems. Of particular interest are magnetic cataclysmic variables, where, plasma flow is directed along the star’s magnetic field lines onto its poles. A stationary shock is formed, several hundred kilometres above the stellar surface; a distance far too small to be resolved with today’s telescopes. Here, we report the results of an analogous laboratory experiment which recreates this astrophysical system. The dynamics of the laboratory system are strongly influenced by the interplay of material, thermal, magnetic and radiative effects, allowing a steady shock to form at a constant distance from a stationary obstacle. Our results demonstrate that a significant amount of plasma is ejected in the lateral direction; a phenomenon that is under-estimated in typical magnetohydrodynamic simulations and often neglected in astrophysical models. This changes the properties of the post-shock region considerably and has important implications for many astrophysical studies.

X-ray backlighter requirements for refraction-based electron density diagnostics through Talbot-Lau deflectometry

Talbot-Lau x-ray interferometers can map electron density gradients in High Energy Density (HED) samples. In the deflectometer configuration, it can provide refraction, attenuation, elemental composition, and scatter information from a single image. X-ray backlighters in Talbot-Lau deflectometry must meet specific requirements regarding source size and x-ray spectra, amongst others, to accurately diagnose a wide range of HED experiments. 8 keV sources produced in the high-power laser and pulsed power environment were evaluated as x-ray backlighters for Talbot-Lau x-ray deflectometry. In high-power laser experiments, K-shell emission was produced by irradiating copper targets (500 × 500 × 12.5 μm³ foils, 20 μm diameter wire, and >10 μm diameter spheres) with 30 J, 8-30 ps laser pulses and a 25 μm copper wire with a 60 J, 10 ps laser pulse. In the pulsed power environment, single (2 × 40 μm) and double (4 × 25 μm) copper x-pinches were driven at ∼1 kA/ns. Moiré fringe formation was demonstrated for all x-ray sources explored, and detector performance was evaluated for x-ray films, x-ray CCDs, and imaging plates in context of spatial resolution, x-ray emission, and fringe contrast.

Epidemiological trends and direct costs of diabetes in a Northern Italy area: 2012 health administrative records analysis LHT n. 20 Verona

OBJECTIVE

This analysis estimates type 1 and type 2 diabetes direct costs in 2012, in terms of hospital care, outpatient visits, diagnostics and medications, in a local healthcare trust in Northern Italy (ULSS n.20 Verona).

METHODS

The Johns Hopkins Adjusted Clinical Group (ACG^®) System was used to analyze data, including hospital discharges, emergency room admissions, medical encounter records, disease registries, copayment exemptions, home care services, psychiatric services, rehabilitation services, and medications. Data from general practitioners and nursing homes were not directly available. Patients obtained from the first analysis were subsequently divided in two groups (type 1 and type 2 diabetes) according to ATC drug classification system and age. Costs were estimated from inpatient and outpatients fees and drugs costs.

RESULTS

ULSS n. 20 takes care of about 480.000 people. We identified 974 people affected by type 1 diabetes (prevalence 0,2%) and 24.087 people affected by type 2 diabetes (prevalence 5,0%) among the residents in 2012. Hospitalization mean annual cost was 4.753,50€ (SD 9.330,19€) for type 1 diabetes and 1.718,08€ (SD 5.087,34€) for type 2 diabetes. Outpatient care mean annual cost was 1.401,76€ (SD 4.394,88€) for type 1 diabetes and 669,15€ (SD 2.121,24€) for type 2 diabetes. Medications mean annual cost was 1,369,35€ (SD1.781,18€) for type 1 diabetes and 874,07€ (SD 2.832,2€) for type 2 diabetes.

CONCLUSIONS

ACG^® diabetes data analysis agrees with data obtained by more expensive methods and seems to be a comprehensive and applicable tool to analyze chronic diseases dynamics in the Italian setting in order to prioritize future research and analyze the effects of interventions aimed to ensure the sustainability of public health services. Because of the combination between prevalence data and epidemiological trends, we could be at the eve of a dramatic increase of diabetes costs with major concerns for the Italian NHS ability to withstand.

Obstrução intestinal por Pythium insidiosum em um cão: relato de caso

Relata-se um caso de pitiose intestinal em um Husky Siberiano, de um ano de idade, macho atendido em um Hospital Veterinário Escola com sinais de obstrução intestinal. Ao exame físico, notou-se massa cilíndrica na região abdominal cranial, posteriormente confirmada por meio de radiografia e ultrassonografia. Durante a laparotomia exploratória, constatou-se massa extraluminal envolvendo o jejuno e alterações na parede do órgão. Realizou-se a ressecção da porção afetada do intestino e, posteriormente, anastomose. O exame histológico do tecido evidenciou inflamação piogranulomatosa acentuada. Na coloração de prata metenamina de Grocott, hifas septadas foram observadas. O diagnóstico de infecção por Pythium insidiosum foi confirmado por meio da imunoistoquímica. Após a cirurgia, o animal restabeleceu a defecação; no 30° dia pós-cirúrgico, foi relatada ainda presença de diarreia. O tratamento com itraconazol e terbinafina foi instituído durante 60 dias. Após dois anos do procedimento cirúrgico e do tratamento com antifúngicos orais, o cão não apresentou recidiva.

[Hysteroscopic features in postmenopausal uterine bleeding]

One hundred forty three patients underwent hysteroscopy for abnormal uterine bleeding from January 1993 through December 1994. Sixty patients were postmenopausal. All but 3 of the procedures were performed on outpatient with no significant complications. Three groups could be identified on the basis of endometrial features (color, vascularity, thickness, necrotic areas): 1) negative for cancer, 2) possible or suspect (low or high risk), 3) carcinoma. Biopsy indicated cancer in one of the 16 doubtful cases, and in all (5) of the hysteroscopically diagnosed cancers. Outpatient Hysteroscopy successfully substitutes D&C (dilatation and curettage) for early diagnosis of endometrial cancer.

[Forceps delivery and long term follow-up urinary incontinence]

553 patients undergoing complete urodynamic evaluation were investigated concerning mode of delivery. Forceps delivery was not associated with worsened urethral competence and significant risk of subsequent incontinence.

[Unstable bladder and Sjögren syndrome. Clinical case]

A female patient developed severe detrusor instability years after a diagnosis of Sjogren syndrome. A common etiology could be possible if an association with viral demyelinization in Sjogren patients is confirmed. Vaginal Sicca syndrome was present and responded to a topical androgen-oestriol association with definite cytologic improvement. Anticholinergics were tolerated and moderately effective. Low initial dose were slowly increased (over three months) to avoid excessive mouth dryness and avoid gastrooesophageal symptoms.

[Ultrasonographic and urodynamic evaluation in stress incontinence]

Transvaginal sonography can show partial urinary penetration in the urethra in patients with no clinical incontinence. The Fluid Bridge Test-Pressure urodynamically demonstrates the same phenomenon. We compared these two technics in women with stress urinary incontinence (SUI). 49 patients underwent urodynamic testing and transvaginal sonography; 18 had SUI, 20 were asymptomatic postoperatively (Burch procedure) and 11 were normal controls. Urodynamics consisted of filling cystometry with saline (infusion speed: ml 70/min) using transurethral Foley catheter (n degree 14 Fr), and a profilometric-pressure Bard catheter (10 Fr); micturitional cystometry; uroflowmetry; clino- and orthostatic urethral pressure profile (UPP) (extraction speed: cm 0.5-1/sec; infusion speed: cm 1.2/min); sphincteric electromyography (EMG); FBT-P with the Bard catheter only. During extraction patients were requested to cough (stress condition). If the urethra is incompetent pressure is transmitted to the water column connected to the pressure transducer, and a "spike" is observed. A competent urethra shows little pressure variation. Ultrasound (US) equipment consisted in a General Electric (RT 3600) sonograph with an electronic transvaginal probe (7.5 MHz) inserted in a gel-lubricated condom. The probe was positioned in the vaginal vestibule in direct proximity to the urethra. Axial and coronal scannings were performed. Echo-imagings were submitted to "post-processing" on US recording equipment. Fluid penetration in the urethra was evident if iperchogenic "turbulence" was observed on playback of the dynamic sonogram on a videocassette recorder (VCR) connected to the sonograph. The SUI group shows leakage of water under stress without detrusorial activity and dynamic UPP with reduced transmission of abdominal pressure on the urethra.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison of methods for the diagnosis of urinary obstruction in women]

The International Continence Society does not offer secure guidelines for the diagnosis of micturitional obstruction. The problem has been extensively addressed in relation to male voiding difficulties. Little is known on the subject in female patients. Two criteria for the diagnosis of obstructed micturition are in clinical use. The Sussett formula divides the maximum micturitional pressure by the square of the corresponding maximum urinary flow rate. Two cutoffs, corresponding approximately to the 90th and 95th centiles can be used (0.15, and 0.5). A more complex graphic nomogram developed by Schafer plots maximum flow versus maximum detrusor pressure, identifying obstruction and detrusor dysfunction simultaneously according to the author. We feel that these methods, extensively tested on a male population, can both be used on a female population. We noticed that in some instances the results were different. 469 women referred for micturitional disturbances underwent pressure/flow studies. 62 (13.2%) were obstructed according to the Schafer nomogram, 103 (21.9%) and 31 (6.6%) respectively using the Sussett mathematical formula using two different cutoffs (0.15 and 0.5). The two methods identify the same patients only if micturitional pressures are normal (40 to 60 cmH2O) to high (over 60 cmH2O) and the Sussett formula is used with a higher (95th centile) cutoff. This means that both methods are clearly insufficient in the diagnosis of obstruction if detrusor function is impaired. This can happen in case of chronic retention due to detrusor failure after a long-standing obstruction or for primary failures due to central nervous system lesions. Extreme care should be exercised if pressure-flow studies indicate obstruction at low micturitional pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

[Acute urinary obstruction in pregnancy]

Five cases of acute urinary obstruction during pregnancy are presented. A complete urodynamic workup, including pressure-flow studies showed high micturitional pressures with little or no flow, with at least 60% residual urine. Filling cystometry, urethral profilometry (static and dynamic), pelvic electromyography were normal. Two cases were due to uterine pelvic incarceration. One of these cases happened very early during pregnancy, because of extensive fibroids. Any cause of abnormal uterine enlargement can lead to early obstruction. Three cases were associated with paraurethral abscess (skenitis in 2 cases, urethral diverticulum in 1). Manual reduction in case of pelvic incarceration or surgical draining and antibiotic therapy in case of abscess were effective in all cases. Immediate catheterization is possible and indicated as soon as urinary obstruction is diagnosed. This prevents neuromuscular dysfunction due to excessive bladder distention. The transurethral catheter might work as a stent, and periurethral surgical drainage is probably safer with a catheter in place. Suprapubic catheterization is probably less useful in this respect. An indwelling catheter removes any urgency in treatment. Voiding difficulties can persist for some days after surgical treatment. Urodynamic testing performed in all indicated acute micturitional obstruction. Anyway, it added little to the clinical understanding of the problem, which was obvious, and the Authors feel that extensive urodynamic testing should be limited to cases presenting with a complex preexisting dysfunction or performed after treatment if symptoms do not disappear completely. All clinically doubtful cases should likewise be investigated. If periurethral abscess or incarceration are evident, simple evaluation of residual urine percentage should be sufficient in establishing the diagnosis.

[Transvaginal estrogen therapy in urinary stress incontinence]

Thirty-four postmenopausal stress incontinence patients were divided in two groups: 17 were treated with 0.5 mg oestriol vaginal cream for 90 days, 17 controls were treated with moisturizing cream. All had low urethral pressures and dystrophy. Treated patients showed improvement of maximum urethral pressure, urethral closure pressure, and volume at first sensation of fullness. Dystrophy was cured in most patients; in 17% incontinence was cured and in 41% subjectively improved.

[Maternal concentration of serum digoxin and concentration in the amniotic fluid and neonatal serum]

Digoxin was assayed in maternal and neonatal sera and in the amniotic fluid in 14 pregnant patients chronically digitalized for mitral stenosis. Neonatal serum levels of digoxin are linearly correlated with maternal concentrations of the drug, and all are inversely related to maternal creatinine clearance. Amniotic fluid levels of the drug are not related to serum levels, but relate to amniotic fluid creatinine concentration. Fetal serum levels are identical to maternal ones for all practical purposes, but bear no relation to amniotic digoxin concentration. Digoxin was assayed with a commercial kit showing very little cross-reactivity with endogenous digoxin-like cross-reacting compounds. Pitfalls in commercial digoxin assays and clinical implications are discussed.

[Polycythemic chorea. Description of a clinical case]

The authors report a 69-year-old man affected by polycythaemia rubra vera since the age of sixty, who presented persistent left hemichorea of acute onset, occurring ten months before the exacerbation of the haematologic abnormalities. Previously he had been suffering from a transient episode of chorea concomitant with relapsing of polycythaemia. CT scan of the brain showed diffuse cortico-subcortical atrophy, whereas Doppler velocimetry of carotid arteries demonstrated a rise in cerebral blood flow resistance and a stenosis of the right carotid artery in its first tract. Pathogenetic mechanisms of chorea complicating polycythaemia vera are discussed and a multifactorial origin of the syndrome is suggested.

The S-100 antigen in cerebrospinal fluid as a possible index of cell injury in the nervous system

The presence of the nervous system-specific S-100 antigen has been tested by microcomplement fixation assay with a monospecific anti-S-100 antiserum in cerebrospinal fluid (CSF) of subjects suffering from psychiatric disorders or various neurological diseases. The antigen was detectable in the CSF of most of the patients with neurological diseases characterized by an appreciable lesion in the nervous parenchyma, whereas it was generally absent from CSF of subjects presumably free from an extensive neurological lesion in the active phase. It is possible that the presence of S-100 IN CSF might be an index of active cell injury in the nervous parenchyma.