FTIR spectral analysis of bituminous binders: reproducibility and impact of ageing temperature

This RILEM round robin study with nine participating laboratories investigated bitumen ageing, its effect on chemical properties and its reproducibility. The impact of temperature used for short-term (RTFOT) binder ageing on the combined short- and long-term (PAV) aged samples was investigated; thereby the effect of reduced mixing temperature such as those relevant for warm mix asphalt technologies on long term ageing was examined. Four 70/100 penetration graded bituminous binders from different sources were selected. In addition to the standard RTFOT temperature of 163 °C, two additional temperatures, 143 and 123 °C were used. The Fourier transform infrared spectroscopy (FTIR) analysis was carried out using an integration method which considers the area below the absorbance spectrum around a band maximum using baseline and tangential approaches. A statistical investigation into the reproducibility of FTIR spectra analysis based on the accumulated data was done. To assess the reproducibility, the coefficient of variation (CV) was taken as a benchmark parameter. Carbonyl and sulfoxide indices were calculated using different baseline correction methods and tangential and baseline integration, respectively. It was shown that the tangential method was not influenced by the applied baseline correction. However, in all considered cases, the tangential method led to significantly worse reproducibility (CVs ranging from 20 to 120%) compared to the baseline method. The sulfoxide indices calculated by both methods were not affected by the baseline correction method used. Impacts of changes in the short-term ageing temperature on short- or long-term aged samples could not be found whereas differences between different binder sources could be detected. RTFOT temperature and therefore mix production temperature had a stronger impact on the formation of sulfoxide structures than for carbonyl structures. The findings from this study show the most reproducible of all considered methods when more than one laboratory is providing FTIR data.     

Relationship between CA 15-3 serum levels and disease extent in predicting overall survival of breast cancer patients with newly diagnosed metastatic disease

Soft tissue sarcomas (STS) of the hand are rare in children and adolescents. From 1965 through 1995, 18 children with STS of the hand were treated at our institution. Rhabdomyosarcoma (RMS) was diagnosed in 11 patients; alveolar histological results predominated (7 of 11 cases). Seven patients presented with metastatic disease and died 4 to 23 months (median, 9 months) from diagnosis; their surgical treatment comprised above-elbow amputation (n = 1), local excision (n = 1), and biopsy (n = 5). For the four patients who presented with localized RMS, surgery consisted of wide local excision (n = 1), local excision (n = 2), or ray amputation (n = 1). With an average follow-up of 5.5 years (range, 4 months to 18 years), 3 of the 11 patients diagnosed with RMS still survive (27%). The remaining seven patients presented with nonrhabdomyosarcomatous soft tissue sarcoma (NRSTS); the most common histological variants were epithelioid and malignant fibrous histiocytoma (two cases each). Surgical treatment for these patients comprised ray amputation (n = 3), wide local excision (n = 3), excisional biopsy (n = 1), and regional lymph node dissection (n = 3). One patient received adjuvant multiagent chemotherapy; three patients received supplemental radiotherapy. Six of the seven (85%) patients are alive with no evidence of disease at an average follow-up of 4.7 years (range, 6 months to 12 years).     

Local impairment of immunoreactivity in HIV-infected women with HPV-related squamous intraepithelial lesions of the cervix

The effect on the nasopharyngeal bacterial flora of therapy for 10 days with co-amoxiclav or cefprozil was studied in 50 children with acute otitis media. Before therapy, potential pathogens (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis) were isolated in 14 (56%) of those treated with co-amoxiclav and 15 (60%) of those treated with cefprozil. Following therapy, the reduction in the number of these pathogens was the same in the two groups. However, differences between the groups were noted in the recovery of organisms with interfering capability, namely alpha-haemolytic streptococci, Peptostreptococcus anaerobius and Prevotella melaninogenica. Fifty interfering organisms were recovered from each group before therapy. After therapy with co-amoxiclav or cefprozil their number declined to 11 and 42, respectively (P< 0.001).     

Measurement of the laser pulse width on the microscope objective plane by modulated autocorrelation method

We report on the construction details of a compact autocorrelator set‐up for the measurement of the width of infrared laser pulses at the focal plane of a microscope for two‐photon excitation fluorescence imaging. One of the novelties of the set‐up, which leads to an improved measurement accuracy, is the use of a modulation technique that is achieved by mounting one of the interferometer mirrors on a loudspeaker driven by a sinusoidal bias at low frequency. A non‐linear least‐square routine selects only that part of the fluorescence signal that is modulated at the same frequency as the loudspeaker bias. To further increase the accuracy, the laser pulse width is obtained from a series of measurements at different values of the modulation bias. The autocorrelator is a compact single bread‐board (10 × 20 cm); it is PC‐controlled both for the acquisition and the analysis of the data and can be coupled to different ports of the microscope. The increase in the pulse width measured for three different ports of the microscope is well accounted for by the group velocity dispersion and the glass thickness of the optics found along these paths.     

On the representative volume element of asphalt concrete at low temperature

The feasibility of characterizing asphalt mixtures’ rheological and failure properties at low temperatures by means of the Bending Beam Rheometer (BBR) is investigated in this paper. The main issue is the use of thin beams of asphalt mixture in experimental procedures that may not capture the true behavior of the material used to construct an asphalt pavement.For the rheological characterization, three-point bending creep tests are performed on beams of different sizes. The beams are also analyzed using digital image analysis to obtain volumetric fraction, average size distribution, and spatial correlation functions. Based on the experimental results and analyses, it is concluded that representative creep stiffness values of asphalt mixtures can be obtained from testing at least three replicates of the thin (BBR) mixture beams.Failure properties are investigated by performing strength tests using a modified Bending Beam Rheometer (BBR), capable of applying loads at different loading rates. Histogram testing of BBR mixture beams and of larger beams is performed and the failure distribution is analyzed based on the size effect theory for quasibrittle materials. Different Weibull moduli are obtained from the two specimens sizes, which indicates that BBR beams do not capture the representative volume element (RVE) of the material.     

High‐yield E‐band diplexer for fixed radio point‐to‐point equipment

The article describes practical guidelines for an E‐Band tuning‐less waveguide diplexer design (71–86 GHz) which requires looser fabrication tolerances and provides higher yield than traditional methods. Physical considerations concerning sensitivity to manufacturing inaccuracies are discussed and proven by designing and manufacturing two different diplexers on a set of typical specifications. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:508–512, 2014.     

Single molecule spectroscopic characterization of GFP-MUT2 mutant for two-photon microscopy applications

Green Fluorescent Protein (GFP) mutants are extensively used in optical microscopy studies of in vivo biological processes in cells. Nonetheless, blinking and bleaching of the GFP chromophore at the single molecule level greatly limits its usefulness. We have worked out what we think are the best experimental conditions for the use of the GFP mutant, GFP-mut2, as a single molecule marker in two-photon excitation measurements. We have measured molecular brightness, excited state lifetime, blinking and photo-bleaching times versus the two-photon excitation intensity on proteins embedded in silica gel matrices versus the excitation wavelength in the range 700-1,000 nm. Our results indicate that GFPmut2 can be employed as a long-lived reporter of biological processes.     

Notes on theory and experimental conditions behind two-photon excitation microscopy

This report deals with the fundamental quantum physics behind two-photon excitation also providing a link to the experimental consequences exploited in microscopy. The optical sectioning effect is demonstrated as well as the distribution of excitation and of fluorescence emission.