Ultrabroadband flying-focus using an axiparabola-echelon pair.

Flying-focus pulses promise to revolutionize laser-driven secondary sources by decoupling the trajectory of the peak intensity from the native group velocity of the medium over distances much longer than a Rayleigh range. Previous demonstrations of the flying focus have either produced an uncontrolled trajectory or a trajectory that is engineered using chromatic methods that limit the duration of the peak intensity to picosecond scales. Here we demonstrate a controllable ultrabroadband flying focus using a nearly achromatic axiparabola-echelon pair. Spectral interferometry using an ultrabroadband superluminescent diode was used to measure designed super- and subluminal flying-focus trajectories and the effective temporal pulse duration as inferred from the measured spectral phase. The measurements demonstrate that a nearly transform- and diffraction-limited moving focus can be created over a centimeter-scale-an extended focal region more than 50 Rayleigh ranges in length. This ultrabroadband flying-focus and the novel axiparabola-echelon configuration used to produce it are ideally suited for applications and scalable to >100 TW peak powers.

Measurements of Non-Maxwellian Electron Distribution Functions and Their Effect on Laser Heating.

Electron velocity distribution functions driven by inverse bremsstrahlung heating are measured to be non-Maxwellian using a novel angularly resolved Thomson-scattering instrument and the corresponding reduction of electrons at slow velocities results in a ∼40% measured reduction in inverse bremsstrahlung absorption. The distribution functions are measured to be super-Gaussian in the bulk (v/v_{th}<3) and Maxwellian in the tail (v/v_{th}>3) when the laser heating rate dominates over the electron-electron thermalization rate. Simulations with the particle code quartz show the shape of the tail is dictated by the uniformity of the laser heating.

Ionization Waves of Arbitrary Velocity.

Flying focus is a technique that uses a chirped laser beam focused by a highly chromatic lens to produce an extended focal region within which the peak laser intensity can propagate at any velocity. When that intensity is high enough to ionize a background gas, an ionization wave will track the intensity isosurface corresponding to the ionization threshold. We report on the demonstration of such ionization waves of arbitrary velocity. Subluminal and superluminal ionization fronts were produced that propagated both forward and backward relative to the ionizing laser. All backward and all superluminal cases mitigated the issue of ionization-induced refraction that typically inhibits the formation of long, contiguous plasma channels.

Insights into the CuO nanoparticle ecotoxicity with suitable marine model species.

Metal oxide nanoparticles, among them copper oxide nanoparticles (CuO NPs), are widely used in different applications (e.g. batteries, gas sensors, superconductors, plastics and metallic coatings), increasing their potential release in the environment. In aquatic matrix, the behavior of CuO NPs may strongly change, depending on their surface charge and some physical-chemical characteristics of the medium (e.g. ionic strength, salinity, pH and natural organic matter content). Ecotoxicity of CuO NPs to aquatic organisms was mainly studied on freshwater species, few tests being performed on marine biota. The aim of this study was to assess the toxicity of CuO NPs on suitable indicator species, belonging to the ecologically relevant level of consumers. The selected bioassays use reference protocols to identify Effect/Lethal Concentrations (E(L)C), by assessing lethal and sub-lethal endpoints. Mortality tests were performed on rotifer (Brachionus plicatilis), shrimp (Artemia franciscana) and copepod (Tigriopus fulvus). While moult release failure and fertilization rate were studied, as sub-lethal endpoints, on T. fulvus and sea urchin (Paracentrotus lividus), respectively. The size distribution and sedimentation rates of CuO NPs, together with the copper dissolution, were also analyzed in the exposure media. The CuO NP ecotoxicity assessment showed a concentration-dependent response for all species, indicating similar mortality for B. plicatilis (48hLC50 = 16.94 ± 2.68mg/l) and T. fulvus (96hLC50 = 12.35 ± 0.48mg/l), followed by A. franciscana (48hLC50 = 64.55 ± 3.54mg/l). Comparable EC50 values were also obtained for the sub-lethal endpoints in P. lividus (EC50 = 2.28 ± 0.06mg/l) and T. fulvus (EC50 = 2.38 ± 0.20mg/l). Copper salts showed higher toxicity than CuO NPs for all species, with common sensitivity trend as follows: P. lividus ≥ T. fulvus (sublethal endpoint) ≥ B. plicatilis >T. fulvus (lethal endpoint) >A. franciscana. CuO NP micrometric aggregates and high sedimentation rates were observed in the exposure media, with different particle size distributions depending on the medium. The copper dissolution was about 0.16% of the initial concentration, comparable to literature values. The integrated ecotoxicological-physicochemical approach was used to better describe CuO NP toxicity and behavior. In particular, the successful application of ecotoxicological reference protocols allowed to produce reliable L(E)C data useful to identify thresholds and assess potential environmental hazard due to NPs.

Meiosis progression and donor age affect expression profile of DNA repair genes in bovine oocytes.

Several genetic and physiological factors increase the risk of DNA damage in mammalian oocytes. Two critical events are: (i) meiosis progression, from maturation to fertilization, due to extensive chromatin remodelling during genome decondensation; and (ii) aging, which is associated with a progressive oxidative stress. In this work, we studied the transcriptional patterns of three genes, RAD51, APEX-1 and MLH1, involved in DNA repair mechanisms. The analyses were performed by real-time quantitative PCR (RT-qPCR) in immature and in vitro matured oocytes collected from 17 ± 3-month-old heifers and 94 ± 20-month-old cows. Batches of 30-50 oocytes for each group (three replicates) were collected from ovarian follicles of slaughtered animals. The oocytes were freed from cumulus cells at the time of follicle removal, or after in vitro maturation (IVM) carried out in M199 supplemented with 10% fetal calf serum, 10 IU luteinising hormone (LH)/ml, 0.1 IU follicle-stimulating hormone (FSH)/ml and 1 µg 17ß-oestradiol/ml. Total RNA was extracted by Trizol method. The expression of bovine GAPDH gene was used as the internal standard, while primers for bovine RAD51, APEX-1 and MLH1 genes were designed from DNA sequences retrieved from GenBank. Results obtained indicate a clear up-regulation of RAD51, APEX-1 and MLH1 genes after IVM, ranging between two- and four-fold compared with germinal vesicle (GV) oocytes. However, only RAD51 showed a significant transcript increase between the immature oocytes collected from young or old individuals. This finding highlights RAD51 as a candidate gene marker for discriminating bovine immature oocytes in relation to the donor age.

Radiolabelled leucocyte scintigraphy versus conventional radiological imaging for the management of late, low-grade vascular prosthesis infections.

PURPOSE: In this study we evaluated the diagnostic performance of (99m)Tc-HMPAO-leucocyte ((99m)Tc-HMPAO-WBC) scintigraphy in a consecutive series of 55 patients (46 men and 9 women, mean age 71 ± 9 years, range 50 - 88 years) with a suspected late or a low-grade late vascular prosthesis infection (VPI), also comparing the diagnostic accuracy of WBC with that of other radiological imaging methods. METHODS: All patients suspected of having VPI underwent clinical examination, blood tests, microbiology, US and CT, and were classified according to the Fitzgerald criteria. A final diagnosis of VPI was established in 47 of the 55 patients, with microbiological confirmation after surgical removal of the prosthesis in 36 of the 47. In the 11 patients with major contraindications to surgery, the final diagnosis was based on microbiology and clinical follow-up of at least 18 months. RESULTS: (99m)Tc-HMPAO-WBC planar, SPECT and SPECT/CT imaging identified VPI in 43 of 47 patients (20 of these also showed infection at extra-prosthetic sites). In the remaining eight patients without VPI, different sites of infections were found. The use of SPECT/CT images led to a significant reduction in the number of false-positive findings in 37% of patients (sensitivity and specificity 100 %, versus 85.1% and 62.5% for stand-alone SPECT). Sensitivity and specificity were 34% and 75% for US, 48.9% and 83.3% for CT, and 68.1% and 62.5% for the FitzGerald classification. Perioperative mortality was 5.5%, mid-term mortality 12%, and long-term mortality 27%. Survival rates were similar in patients treated with surgery and antimicrobial therapy compared to patients treated with antimicrobial therapy alone (61% versus 63%, respectively), while infection eradication at 12 months was significantly higher following surgery (83.3% versus 45.5%). CONCLUSION: (99m)Tc-HMPAO-WBC SPECT/CT is useful for detecting, localizing and defining the extent of graft infection in patients with late and low-grade late VPI with inconclusive radiological findings. (99m)Tc-HMPAO-WBC SPECT/CT might be used to optimize patient management.

Nuclear factor-kappa-B-inhibitor alpha (NFKBIA) is a developmental marker of NF-κB/p65 activation during in vitro oocyte maturation and early embryogenesis.

BACKGROUND: The oocyte-to-embryo transition (OET) requires a co-ordinated transcriptional programme acting through evolutionarily conserved events, and transcription factors (TFs) are known to control these processes. Here, we focus on nuclear factor (NF)-κB, a TF involved in several cellular processes, studying NFκB-inhibitor (NFKBIA) mRNA and its protein product, IκBα, during OET. NFKBIA and IκBα are part of a regulatory loop, as IκBα is the major down-regulator of NF-κB activation while NFKBIA transcription is activated by NF-κB. METHODS AND RESULTS: We found a dynamic correlation between NFKBIA transcript, expression of IκBα-protein and activation of NF-κB/p65 in bovine oocyte and embryo. During the transition from immature to in vitro matured bovine oocyte, we observed a decrease in maternal NFKBIA mRNA and a parallel increase of the IκBα-protein (both P < 0.05). In the embryo, NFKBIA neo-synthesis is activated as a consequence of embryo genome activation (EGA), and IκBα decreases. NF-κB/p65-binding activity was detectable at low levels in immature oocyte, disappeared in dormant metaphase II oocyte and was strong in the embryo, during embryonic NFKBIA synthesis. The level of NF-κB/p65 DNA binding correlates with the timing of meiotic silencing during bovine oocyte maturation and embryonic transcription reprogramming. CONCLUSIONS: The IκBα/NF-κB circuit appears to be a tightly stage-controlled mechanism that could govern OET, being activated at EGA. Our findings represent the first characterization of NFKBIA and IκBα as maternal effectors in both the bovine oocyte and embryo. We suggest a role for NFKBIA as a marker of NF-κB/p65 activation in the human oocyte and early embryo.

Ca2+ signaling during maturation of cumulus-oocyte complex in mammals.

Under the influence of gonadotropins or growth factors, a close cooperation develops between cumulus cells and the oocyte that is implicated in transmitting signals involved in maintaining or releasing the meiotic arrest in the oocyte. While cyclic adenosine 5'-monophosphate (cAMP) is a key molecule in maintaining the meiotic arrest, calcium (Ca(2+)) may play a role in controlling either spontaneous or gonadotropin-induced oocyte maturation, possibly by modulating intracytoplasmic cAMP concentrations via Ca(2+)-sensitive adenylate cyclases. This review focuses on the mechanisms related to the origin of the Ca(2+) wave that travels from the cumulus cells to the oocyte, and discusses the source of variations affecting the dynamics of this wave.

[Spinning-induced rhabdomyolysis: importance of MRI for patient's outcome. A case report]. / Su un caso di rabdomiolisi da spinning: valore prognostico della RMN.

The first Italian case of spinning-induced exertional rhabdomyolysis is presented here. The spinning is an expanding fitness activity which uses a stationary bike, that in some rare cases described in literature can induce rhabdomyolysis. In our patient, through magnetic resonance imaging, we detected a clear-cut temporal dissociation between clinical-biochemical healing and anatomical recovery. In fact we found that the improvement of magnetic resonance picture was much slower than the vanishing of myalgias and normalization of serum myoglobin and enzymes. This observation could be useful to understand the timing for exercise resumption without any risk for the patient.

The Scattered Light Time-history Diagnostic suite at the National Ignition Facility.

The Scattered Light Time-history Diagnostic (SLTD) is being implemented at the National Ignition Facility (NIF) to greatly expand the angular coverage of absolute scattered-light measurements for direct- and indirect-drive inertial confinement fusion (ICF) experiments. The SLTD array will ultimately consist of 15 units mounted at a variety of polar and azimuthal angles on the NIF target chamber, complementing the existing NIF backscatter suite. Each SLTD unit collects and diffuses scattered light onto a set of three optical fibers, which transport the light to filtered photodiodes to measure scattered light in different wavelength bands: stimulated Brillouin scattering (350 nm-352 nm), stimulated Raman scattering (430 nm-760 nm), and ω/2 (695 nm-745 nm). SLTD measures scattered light with a time resolution of ∼1 ns and a signal-to-noise ratio of up to 500. Currently, six units are operational and recording data. Measurements of the angular dependence of scattered light will strongly constrain models of laser energy coupling in ICF experiments and allow for a more robust inference of the total laser energy coupled to implosions.

Experimental demonstration of emittance compensation with velocity bunching.

In this Letter we report the first experiments aimed at the simultaneous demonstration of the emittance compensation process and velocity bunching in a high brightness electron source, the SPARC photoinjector in INFN-LNF. While a maximum compression ratio up to a factor 14 has been observed, in a particular case of interest a compression factor of 3, yielding a slice current of 120 A with less than 2 microm slice emittance, has been measured. This technique may be crucial in achieving high brightness beams in photoinjectors aiming at optimized performance of short wavelength single-pass free electron lasers or other advanced applications in laser-plasma accelerators.

Test of "crab-waist" collisions at the DAPhiNE Phi factory.

The electron-positron collider DAPhiNE, the Italian Phi factory, has been recently upgraded in order to implement an innovative collision scheme based on large crossing angle, small beam sizes at the crossing point, and compensation of beam-beam interaction by means of sextupole pairs creating a "crab-waist" configuration in the interaction region. Experimental tests of the novel scheme exhibited an increase by a factor of 3 in the peak luminosity of the collider with respect to the performances reached before the upgrade. In this Letter we present the new collision scheme, discuss its advantages, describe the hardware modifications realized for the upgrade, and report the results of the experimental tests carried out during commissioning of the machine in the new configuration and standard operation for the users.

Independent Functioning in Nonagenarians Living in a Rural Italian Community: The Mugello Study.

Nonagenarians are a fast-growing population deserving specific research. We explored the prevalence and characteristics of functionally independent nonagenarians from a rural community-dwelling Italian population. Data were collected in the Mugello Study; 475 persons aged ≥90 years (median age, 92) underwent a home-based clinical and functional assessment, including psychosocial, clinical, functional, and lifestyle history and status and physical and instrumental examinations. Sixty-eight (15%) persons reported no need for help in basic and instrumental daily living activities. Among variables significantly associated with independent functionality after age- and gender-adjusted cross-sectional analysis, lower body mass index (BMI; p = .034) and depressive symptoms (p = .028), higher current physical activity (p < .001), better cognitive status (p = .033), and lower medication intake (p = .048) were associated with reporting no disability in the logistic regression analysis. Disability was mainly associated with current lifestyle-related potentially modifiable factors. Thus, lifestyle-oriented multidimensional interventions, should be developed and evaluated for their potential effects on functionality, even in the oldest old.

Allocation of deceased donor kidneys in São Paulo, Brazil: effect of human leukocyte antigen compatibility on graft survival.

In Brazil, organ transplantation has been regulated by a federal law since 1997. This law was created to guarantee equal access to treatment on a national scale. Deceased donor organ procurement and sharing are centralized and controlled by the Health Department of each state of the nation, following a regional allocation policy. In São Paulo, time on the waiting list was the main criterion adopted to allocate deceased donor kidneys up to January 1, 2002. After that, HLA mismatches (MM) were the main criterion. The aim of this study was to investigate the impact of HLA compatibility on graft survival among 3312 consecutive kidney recipients. The 2-year kidney graft survival rates were compared among recipients transplanted based on the waiting time policy and based on HLA MM. Better results were observed in the HLA MM group (78.1% vs 64.9%; P < .0001). Regarding kidney allocation based on HLA MM, recipients transplanted with 0 HLA-A, -B, or -DR MM showed significantly better 5-year survival rates than those with 1-2 or 3-4 or 5-6 HLA-A, -B, or -DR MM (70.36% vs 64.71% vs 58.07% vs 55.64%; P < .050). We concluded that HLA compatibility is a feasible criterion to allocate deceased donor kidneys in Brazil.

Model for end-stage liver disease: impact of the new deceased donor liver allocation policy in São Paulo, Brazil.

Since 1997, organ transplantation in Brazil has been regulated by a federal law, which was created to guarantee equal access to treatment on a national scale. Centralized deceased donor organ procurement and sharing are controlled by the Health Department of each state of the nation, following a regional allocation policy. In São Paulo, time on the waiting list was the main criterion adopted to allocate deceased donor livers up to July 15, 2006. After that, model for end-stage liver disease/pediatric end-stage liver disease (MELD/PELD) scores were the main criteria. The aim of this study was to investigate the impact of the new criteria on patient survival rates using 895 consecutive liver recipients. The 1-year patient survival rates were compared between recipients transplanted based on the waiting time policy and based on MELD/PELD scores showing similar results (69.79% vs 66.69%; P = NS). Regarding liver allocation based on MELD/PELD scores, worse survival outcomes were observed among recipients transplanted with higher MELD scores. Also, under the new criteria, a high frequency of hepatocellular carcinoma and pediatric recipients underwent transplantation.

A rate-doubled 10-GHz fiducial comb generator for precision optical timing calibration.

Solid-state optical fiducial timing pulse generators provide a convenient and accurate method to include timing fiducials in a streak-camera image for time-base correction. Current commercially available vertical-cavity surface-emitting lasers (VCSELs) emitting in the visible range can be amplitude modulated up to 5 GHz. An optically passive method is utilized to interleave a time-delayed path of the 5-GHz pulsed light with itself, producing a 10-GHz pulsed fiducial, or comb. Comb pulse rates at 0.5, 1.0, and 2.5 GHz can also be selected. The instrument presented is a self-contained and portable generator with primary use for streak-camera temporal calibration. Applications can also be extended to many other optical timing needs. The VCSEL output is fiber optic coupled at a wavelength of 680 nm (visible red) with a nearly Gaussian pulse shape. The peak power of each ∼50-ps full width at half maximum (FWHM) comb pulse at 5-GHz operation, or picket, is approximately 5 mW. The low phase noise of the internal microwave modulation drive source provides low pulse to pulse jitter. An external reference frequency standard can be utilized to synchronize the output to external timing equipment. A selectable internal reference frequency crystal oscillator is incorporated for stand-alone operation.

Impact of Skull Defects on the Role of CTA for Brain Death Confirmation.

BACKGROUND AND PURPOSE: Intracranial pressure modifications caused by a skull defect, such as craniectomy or craniotomy, may change the hemodynamics and decrease the accuracy of CTA to confirm brain death. This study aimed to evaluate the impact of a skull defect and the interpretation criteria of images on this diagnostic test. MATERIALS AND METHODS: A series of consecutive patients with a clinical diagnosis of brain death underwent CTA (case group), while the control group comprised patients with acute ischemic stroke in the same period. CTA criteria adopted to confirm brain death were the absence of opacification of the M4 branches and internal cerebral veins. The evaluation also included the presence of "stasis filling." Cases were stratified as intact skull, craniotomy, and craniectomy. Three neuroradiologists evaluated all examinations independently. RESULTS: In the case group, according to the Frampas criteria, the sensitivity of CTA to confirm brain death was 95.5% in patients with intact skull, 87.5% with craniotomy, and 60% with craniectomy. False-negative diagnoses of brain death were 15.6%, related to stasis filling in 71.4% (P < .001). However, according to the "modified Frampas criteria," the sensitivity of CTA to confirm brain death was 100% in patients with intact skull, 93.8% with craniotomy, and 80% with craniectomy. False-negative diagnoses of brain death were found in 6.2% of patients, and there was no stasis filling. CTA showed 100% specificity in the control group. There were no disagreements among observers. CONCLUSIONS: CTA had a high diagnostic accuracy and reproducibility to confirm brain death in patients with an intact skull. The modified Frampas criteria increased the sensitivity of CTA, particularly in patients with a skull defect. A concurrent skull defect, especially craniectomy, can decrease the sensitivity of CTA to confirm brain death.

Juvenile and adult immature and in vitro matured ovine oocytes evaluated in relation to membrane electrical properties, calcium stores, IP3 sensitivity and apoptosis occurrence in cumulus cells.

The analysis of differences between juvenile and adult oocytes may provide useful information on the acquisition of meiotic and developmental competence of the female gamete. In oocytes collected from either ewes or 40-day-old lambs, we evaluated membrane electrical properties, such as resting potential, conductance, activation ion currents, L-type Ca(2+) currents as well as calcium stores and IP3 sensitivity; in addition, the incidence of apoptosis in cumulus cells in these two age categories was compared. The analysis was carried out in oocytes both prior to and after in vitro maturation. Significant differences were found in all the examined parameters in relation to maturational stages whereas minor differences were recorded in relation to age of the donor. IP3 sensitivity strongly increased after in vitro maturation following a dose-dependent pattern from 1 to 500 micromol/L with a significant interaction (P < 0.01) between dose and maturational stage. The incidence of apoptosis in cumulus cells strongly increased after in vitro maturation and was greater in adult than in juvenile cumulus cells (39.2 +/- 5.8% vs. 21.9 +/- 3.5%; P < 0.01). In conclusion, all the examined parameters were greatly affected by the maturational stage, whereas minor differences were due to age-related oocyte quality, that is, at plasma membrane levels to conductance, activation current peaks and calcium currents, at cytosol level to calcium stores and IP3 sensitivity, and to incidence of apoptosis in cumulus cells. These parameters were compared with previous data in bovine to analyze oocyte quality in juvenile and adult individuals or between species.

Implementation of a Wollaston interferometry diagnostic on OMEGA EP.

A Wollaston interferometer is presented for use in measuring the electron density of plasma plumes created in experiments on the OMEGA EP laser system. The diagnostic is installed as an additional arm on the 4ω probe system, a suite of diagnostics that share a 10 ps pulse of 263 nm laser light captured by an imaging system at f/4. The interferometer utilizes a Wollaston prism to create two angularly separated beams from a single input probe beam, split at any angle between 0° and 90°. This configuration is implemented uniquely such that fringe spacing may be altered independently of field of view, magnification, and imaging resolution, from a range of 17 to 76 µm/fringe. The region of overlap between the two beams forms a total field of view of approximately 1.2 × 1.6 mm at the target chamber center with an imaging resolution of 5 µm. Using this configuration, here it is shown that plasma density may be accurately characterized over a range of 3 × 1018-1 × 1020 cm-3.