Search

To address the paucity of experimental data on well-documented turbulent jet flames at elevated pressures, a high pressure rig has been used to explore turbulent nonpremixed syngas flames at elevated pressures and very high Reynolds numbers. Composite images of the flames reveal small changes in flame length that are in agreement with previous empirical correlations. OH-PLIF images are used to visualize the flame structure, revealing an OH layer that gets progressively thinner as pressure increases. A corrugation factor is defined and used to show that flame front corrugation is influenced by increases in Reynolds number and axial distance from the nozzle, but not pressure. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical accuracy of magnetic resonance imaging-guided breast vacuum-assisted biopsy (MR-VAB).Methods: Of 97 scheduled MR-VAB for single MRI lesions (negative second-look sonography) categorised as BI-RADS 4 or 5, 4 were cancelled (undetected lesion = 2, technical problems = 2). Twenty-one patients lost to follow-up were excluded.Results: Twenty-three patients (median age 51 years) were at high risk (BRCA1 = 11, BRCA2 = 7, familial risk = 5), 23 had a suspected local recurrence of breast cancer. Seventy-two imaged lesions (focus = 1, mass enhancement = 32, non-mass-like enhancement = 39) were targeted with a 10-gauge VAB probe using MRI guidance, with a median of 18 specimens per lesion (median procedural time 72 min, range 50-131 min) followed by clip placement. In the case of benignity, MRI follow-up was performed (19 patients, median 389 days, range 33-1,592) or mammography (3 patients, median 420 days, range 372-1,354). According to histopathology results, 29 lesions were benign, 10 were high-risk (papillary = 2, radial scar = 1, atypical epithelial hyperplasia = 7) and 33 malignant (ductal carcinoma in situ = 8, invasive cancers = 25). Three false negative results and 3 complications occurred (1 malaise, 1 skin defect, 1 infection).Conclusion: MRI-guided VAB represents an accurate tool for the histological diagnosis of lesions visible only at MRI. [ABSTRACT FROM AUTHOR]

Background:The identification and validation of suitable predictive and prognostic factors are a challenge to improve the treatment scheme selection. Discordances in histological grade can be established between core biopsy and surgical specimens. This is important in HR-positive/HER2-negative subgroup where histological grade identifies patients at high risk and is a strong determinant for treatment scheme.Methods:A total of 350 consecutive invasive breast carcinoma biopsies were assessed and compared with surgical specimens in Institut Curie, Paris, France. Clinical, radiological and pathological data were recorded.Results:Histological grade concordance rate in the HR+/HER2− group was 75%. A grade underestimation was mainly due to mitotic index misgrading (23%). Large tumours (P<0.05), premenopausal patients (P=0.005) and non-ultrasound-guided biopsies (P=0.04) were risk factors for misgrading. The highest discordance was found in tumours that required chemotherapy (39%, P<0.05), and it was related to an underestimation of histological grade on core biopsies (94%).Conclusions:Histological grade in HR+/HER2− group is important to identify patients with poor prognosis and start a systemic therapy. Histological grade discordance was correlated with an underestimation of mitotic index and factors probably associated with intratumor heterogeneity (premenopausal status, tumour size and the type of core biopsy performed). But such discordance did not appear to modify the therapeutic decision, because systemic treatment decision-making also integrates other variables. Determining histological grade in core biopsy can be especially important in HR-positive/HER2-negative subgroup where it identifies patients at high risk and is a strong determinant of the treatment scheme. [ABSTRACT FROM AUTHOR]

A nonlinear extended finite element (XFEM) modeling framework under a stochastic cohesive zone is presented for realistic prediction of delamination in polyphenylene sulfide (PPS)/glass composites in mode I of fracture. The cohesive zone model adopts damage evolution of the material based on a bilinear traction-separation law, the critical energy release rate and the J-integral method to formulate the delamination interface under stochastic fracture properties. To demonstrate the application of the approach, numerical predictions are compared to experimental data using Double Cantilever Beam (DCB) tests. In particular, it is shown how the XFEM model can be used to capture test non-repeatability due to uncertain fracture properties, which is often the case during the characterization of composites using standard fracture tests. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluated the feasibility, safety, effectiveness, and long-term results of pelvic organ prolapse surgery using the Da Vinci robotic system. Methods: During a 7-year period, 52 consecutive patients with pelvic organ prolapse underwent robotic-assisted abdominal sacrocolpopexy. Clinical data were retrospectively collected and analyzed. Results: All but two of the procedures were successfully completed robotically (96 %). Median operative time was 190 (range, 75-340) mins. There was no mortality and no specific morbidity due to the robotic approach. Mean hospital stay was 5 days. The median follow-up was 42 months. Five recurrent prolapses (9.6 %) were diagnosed. Conclusions: Our experience indicates that using the Da-Vinci robotic system is feasible, safe, and effective for the treatment of pelvic organ prolapse with good long-term results. [ABSTRACT FROM AUTHOR]

Objective: To assess the diagnostic accuracy of Dual-Energy Contrast-Enhanced Digital Mammography (CEDM) as an adjunct to mammography (MX) versus MX alone and versus mammography plus ultrasound (US).Materials and Methods: 120 women with 142 suspect findings on MX and/or US underwent CEDM. A pair of low- and high-energy images was acquired using a modified full-field digital mammography system. Exposures were taken in MLO at 2 min and in CC at 4 min after the injection of 1.5 ml/kg of an iodinated contrast agent. One reader evaluated MX, US and CEDM images during 2 sessions 1 month apart. Sensitivity, specificity, and area under the ROC curve were estimated.Results: The results from pathology and follow-up identified 62 benign and 80 malignant lesions. Areas under the ROC curves were significantly superior for MX+CEDM than it was for MX alone and for MX+US using BI-RADS. Sensitivity was higher for MX+CEDM than it was for MX (93% vs. 78%; p < 0.001) with no loss in specificity. The lesion size was closer to the histological size for CEDM. All 23 multifocal lesions were correctly detected by MX+CEDM vs. 16 and 15 lesions by MX and US respectively.Conclusion: Initial clinical results show that CEDM has better diagnostic accuracy than mammography alone and mammography+ultrasound. [ABSTRACT FROM AUTHOR]

Integral cross sections and pressure broadening coefficients have been measured for the acetylene — neon system by a molecular beam scattering technique and by high infrared resolution spectroscopy, respectively. We have performed quantal calculations using an ab-initio potential energy surface (PES) [J. Chem. Phys. 109, 8968 (1998)]. Results are found to be in good agreement with both measured integral cross sections and pressure broadening coefficients for the two temperatures investigated (173 and 298 K). We have also derived a semi-empirical PES parameterized using an atom-bond pairwise additive scheme. This PES shows an isotropic component in agreement with the ab-initio calculation, reproduces the scattering data but it only leads to a reasonable agreement for the pressure broadening coefficients. [ABSTRACT FROM AUTHOR]

This paper reviews the different techniques available and competing for full-field digital mammography. The detectors are described in their principles: photostimulable storage phosphor plates inserted as a cassette in a conventional mammography unit, dedicated active matrix detectors (i.e., flat-panel, thin-film transistor-based detectors) and scanning systems, using indirect and direct X-ray conversion. The main parameters that characterize the performances of the current systems and influence the quality of digital images are briefly explained: spatial resolution, detective quantum efficiency and modulation transfer function. Overall performances are often the result of compromises in the choice of technology. [ABSTRACT FROM AUTHOR]

Demonstrates that a two base pair deletion in alpha 7 nicotinic acetylcholine receptor-like gene located in chromosome 15 is a risk factor for P50 auditory-evoked potential gating. Association of abnormality in P50 sensory gating with schizophrenia; Types of genetic variations affecting the gene.

Background. Pseudometastatic lesions of the liver may be discovered incidentally in children previously treated for malignant tumour.¶Objective. To describe the radiological pattern of these lesions and to analyse their pathogenesis.¶Materials and methods. Nine children, 2–12 years' old at the time of diagnosis, are described in this retrospective multicentre report. The primary tumours were: nephroblastoma (n = 2), neuroblastoma (n = 2), Ewing's tumour/PNET (n = 2), non-Hodgkin's lymphoma (n = 1), and osteosarcoma (n = 2), treated by surgery (8/9), chemotherapy (9/9), intensive chemotherapy and bone-marrow transplantation (5/9), and radiotherapy (7/9). Three children suffered veno-occlusive disease (VOD) during treatment. The hepatic assessment was performed by sonography (8/9), Doppler (7/9), multiphase spiral CT (8/9) and MRI (7/9).¶Results. Lesions were discovered 15 months to 16 years after completing treatment. CT was the most sensitive modality for diagnosis. Lesions were multiple in eight cases, measured 2–50 mm, and appeared hypervascular on the arterial phase of CT and/or MRI in every case. Metastases were excluded on the basis of histological verification (n = 2) and clinical and radiological follow-up.¶Conclusion. Pseudometastatic hypervascular hepatic nodules can appear after treatment of a malignant tumour in children. The hypothesis of benign regenerative lesions secondary to treatment and/or VOD is considered. [ABSTRACT FROM AUTHOR]

Line mixing effects have been studied in the band of perturbed by helium. Theoretical absorption coefficients are compared to FTIR measurements, which were made at room temperature for helium pressure from 1 atm up to 90 atm. The observed strong modifications with respect to additive Lorentzian contributions are explained by line coupling effects. The Infinite Order Sudden Approximation and the Energy Corrected Sudden Approximation are used in order to account for these effects. The latter gives better agreement: it rather successfully predicts the band shape and the linewidths. [ABSTRACT FROM AUTHOR]