Concrete Pavement Mixture Design and Analysis (MDA): Application of a Portable X-Ray Fluorescence Technique to Assess Concrete Mix Proportions , TPF-5(205), 2012

Any transportation infrastructure system is inherently concerned with durability and performance issues. The proportioning and uniformity control of concrete mixtures are critical factors that directly affect the longevity and performance of the portland cement concrete pavement systems. At present, the only means available to monitor mix proportions of any given batch are to track batch tickets created at the batch plant. However, this does not take into account potential errors in loading materials into storage silos, calibration errors, and addition of water after dispatch. Therefore, there is a need for a rapid, cost-effective, and reliable field test that estimates the proportions of as-delivered concrete mixtures. In addition, performance based specifications will be more easily implemented if there is a way to readily demonstrate whether any given batch is similar to the proportions already accepted based on laboratory performance testing. The goal of the present research project is to investigate the potential use of a portable x-ray fluorescence (XRF) technique to assess the proportions of concrete mixtures as they are delivered. Tests were conducted on the raw materials, paste and mortar samples using a portable XRF device. There is a reasonable correlation between the actual and calculated mix proportions of the paste samples, but data on mortar samples was less reliable.

Myosin, tubulin and laminin immunoreactivity in the ectoderm of the growing area opaca of the chick embryo

Distribution of myosin, tubulin and laminin immunoreactive cells in the area opaca of the young chick embryo (Stages 4-8 HH) was studied using immunofluorescence technique. For the three markers, the number of stained cells increased with the age of the blastoderm. Cells stained for tubulin and laminin, were distributed throughout the area opaca, showing no supracellular organization. On the contrary, the cells stained for myosin became organized in a ring surrounding the area pellucida. This pattern appeared at the stage 6. Such an heterogenous distribution of the markers suggests a functional diversification of the ectodermal cell monolayer forming at these early developmental stages the area opaca. This idea is also supported by the results of autoradiography for tritiated thymidin which showed that the edge cells did not synthetize DNA and consequently did not divide.

MDCT arthrography of the hip: value of the adaptive statistical iterative reconstruction technique and potential for radiation dose reduction.

OBJECTIVE: The purpose of this article is to assess the effect of the adaptive statistical iterative reconstruction (ASIR) technique on image quality in hip MDCT arthrography and to evaluate its potential for reducing radiation dose. SUBJECTS AND METHODS: Thirty-seven patients examined with hip MDCT arthrography were prospectively randomized into three different protocols: one with a regular dose (volume CT dose index [CTDIvol], 38.4 mGy) and two with a reduced dose (CTDIvol, 24.6 or 15.4 mGy). Images were reconstructed using filtered back projection (FBP) and four increasing percentages of ASIR (30%, 50%, 70%, and 90%). Image noise and contrast-to-noise ratio (CNR) were measured. Two musculoskeletal radiologists independently evaluated several anatomic structures and image quality parameters using a 4-point scale. They also jointly assessed acetabular labrum tears and articular cartilage lesions. RESULTS: With decreasing radiation dose level, image noise statistically significantly increased (p=0.0009) and CNR statistically significantly decreased (p=0.001). We also found a statistically significant reduction in noise (p=0.0001) and increase in CNR (p≤0.003) with increasing percentage of ASIR; in addition, we noted statistically significant increases in image quality scores for the labrum and cartilage, subchondral bone, overall diagnostic quality (up to 50% ASIR), and subjective noise (p≤0.04), and statistically significant reductions for the trabecular bone and muscles (p≤0.03). Regardless of the radiation dose level, there were no statistically significant differences in the detection and characterization of labral tears (n=24; p=1) and cartilage lesions (n=40; p≥0.89) depending on the ASIR percentage. CONCLUSION: The use of up to 50% ASIR in hip MDCT arthrography helps to reduce radiation dose by approximately 35-60%, while maintaining diagnostic image quality comparable to that of a regular-dose protocol using FBP.

A novel technique for the reconstruction of infected full-thickness chest wall defects.

BACKGROUND: Chest wall resection and reconstruction can be performed with minimal mortality and excellent functional and cosmetic results using synthetic meshes, methylmethacrylate, or other substitutes. However, these techniques are less easily applicable if chest wall resections have to be performed for infections. METHODS: We report a novel technique for this purpose using a modified latissimus dorsi flap harvested in continuity with the thoracolumbar fascia. The vascularized fascia was sutured into the chest wall defect, providing a stable base for the muscular component of the flap. Three patients requiring large full-thickness resections of the anterolateral chest wall for chronic infections were treated accordingly, two presenting with chronic radionecrosis and osteomyelitis and one with chest wall invasion by pulmonary aspergillosis. RESULTS: There were no intraoperative or postoperative complications and immediate extubation was possible in all 3 patients without the need for postoperative ventilation or tracheotomy. Healing of the infected chest wall was observed in all 3 patients. Postoperative cinemagnetic resonance imaging revealed concordant movements of the replaced segments without evidence of paradoxical motion during inspiration and expiration. CONCLUSIONS: This technique is easy and safe. It allows a stable and satisfactory reconstruction after large anterolateral full-thickness chest wall resections of infected, previously irradiated tissues, using only well-vascularized autologous tissue.

Esophageal and pharyngeal strictures: report on 1,862 endoscopic dilatations using the Savary-Gilliard technique

Treatment of symptomatic pharyngeal and esophageal strictures requires endoscopic dilatation. The Savary-Gilliard bougienage was developed by our department and has been used since 1980 for this purpose. We report our experience using this technique. The records of patients seen from January 1, 1963 to December 31, 2005, who had pharyngeal and esophageal strictures needing dilatation, were reviewed. The prevalence of different etiologies, and the incidence of complications using the Savary-Gilliard dilators were assessed. Efficiency of dilatation was assessed over a 17-year segment of this period, using number of dilatations and time intervals between dilatations until resolution of symptoms as outcome measures. Of the 2,652 pharyngeal and esophageal strictures reviewed, 90% were of organic origin (45% benign and 55% malignant stenoses), and 10% were of functional etiology. The most common etiologies were peptic strictures before the era of proton pump inhibitors, and postoperative anastomotic strictures thereafter. A total of 1,862 dilatations using the Savary-Gilliard technique were analyzed. Complication and mortality rates were 0.18 and 0.09% for benign and 4.58 and 0.81% for malignant etiologies, respectively. The number of dilatations per stricture and the time interval between different sessions were dependent on the type of strictures, varying from 1 to 23 dilatations and 7 days to 16 years, respectively. Pharyngeal and esophageal dilatations using the Savary-Gilliard technique were safe when used together with fluoroscopy. Overall, the efficiency of the dilatation procedure was good, but some types of strictures (e.g., caustic, post-surgical and/or post radiotherapy) were refractory to treatment and required repeated dilatations.

Behavior of nuclear matrix proteins during camptothecin-induced apoptosis in HL-60 human leukemia cells.

In this study we focused our attention on the behavior of four nuclear matrix proteins during the various stages of apoptosis in the HL-60 cell line exposed to the DNA topoisomerase I inhibitor, camptothecin. We have examined the following antigens by immunocytochemical techniques: (i) the 180-kDa nucleolar isoform of DNA topoisomerase II; (ii) a 126-kDa polypeptide of nuclear bodies; (iii) a 125-kDa protein; and (iv) a 160-kDa polypeptide which are known to be components of the matrix inner network. Indirect immunofluorescence experiments were performed to follow these nuclear matrix antigens during apoptosis. Moreover, the ultrastructural localization of both 125- and 160-kDa proteins was investigated by electron microscope immunocytochemistry with gold-conjugated secondary antibodies. While the antibody to the nucleolar isoform of DNA topoisomerase II gave a fluorescent pattern that was well-maintained until the late phases of apoptosis, the other three nuclear antigens showed marked modifications in their distribution. A common feature, particularly evident for 125- and 160-kDa proteins, was their absence from cap-shaped chromatin marginations, whereas they were present in the areas of remaining decondensed chromatin. The 126-kDa polypeptide concentrated progressively in an irregular mass at the opposite side of the crescentic caps and then broke up in fine spots. The 125- and 160-kDa proteins localized in the nucleolus and precisely within certain granules which are known to appear in the nucleolar area after camptothecin administration. These results show that, in addition to the well-known chromatin changes, nuclear organization undergoes other rearrangements during the apoptotic process.

Sea Urchins Predation Facilitates Coral Invasion in a Marine Reserve

Macroalgae is the dominant trophic group on Mediterranean infralittoral rocky bottoms, whereas zooxanthellate corals are extremely rare. However, in recent years, the invasive coral Oculina patagonica appears to be increasing its abundance through unknown means. Here we examine the pattern of variation of this species at a marine reserve between 2002 and 2010 and contribute to the understanding of the mechanisms that allow its current increase. Because indirect interactions between species can play a relevant role in the establishment of species, a parallel assessment of the sea urchin Paracentrotus lividus, the main herbivorous invertebrate in this habitat and thus a key species, was conducted. O. patagonica has shown a 3-fold increase in abundance over the last 8 years and has become the most abundant invertebrate in the shallow waters of the marine reserve, matching some dominant erect macroalgae in abundance. High recruitment played an important role in this increasing coral abundance. The results from this study provide compelling evidence that the increase in sea urchin abundance may be one of the main drivers of the observed increase in coral abundance. Sea urchins overgraze macroalgae and create barren patches in the space-limited macroalgal community that subsequently facilitate coral recruitment. This study indicates that trophic interactions contributed to the success of an invasive coral in the Mediterranean because sea urchins grazing activity indirectly facilitated expansion of the coral. Current coral abundance at the marine reserve has ended the monopolization of algae in rocky infralittoral assemblages, an event that could greatly modify both the underwater seascape and the sources of primary production in the ecosystem.

Macular and retinal dysfunction of unknown origin in adults with normal fundi: evidence for an autoimmune pathophysiology.

Here we report the discovery of and phenotypic characterization of a retinal disorder of unknown origin in adults using clinical, electrophysiological and psychophysical techniques, and to seek the presence of circulating retinal autoantibodies in the sera of these patients. Sixteen patients were identified with progressive bilateral visual loss over a period of months. Ten of the patients were male, and the average age was 55.3 years (range from 43 to 76 years). Known causes such as carcinoma-associated retinopathy, acute zonal occult outer retinopathy and hereditary cone dystrophy appeared unlikely. Investigations included electrophysiology, fundus autofluorescence imaging and psychophysical tests. The sera of these patients were analyzed with indirect immunocytochemistry and Western immunoblot analysis on murine (BALB/c) retinal tissue for the presence of retinal autoantibodies. Bilateral visual loss and photophobia progressed over a period of months to years (average 28.7 months, range 3-67) and subsequently stabilized. No abnormality was observed by biomicroscopy, angiography or autofluorescence imaging. Electrophysiology indicated predominant cone-system dysfunction, either macular or generalized, and post-phototransduction involvement in 9 patients (56%). Photopic and scotopic visual fields and dark adaptation kinetics showed both cone and rod system involvement in all cases. Heterogeneous immunohistochemical staining patterns were seen with the sera of these patients as compared with controls. A majority of the affected patients (9/15) stained with an antinuclear pattern. The retinal autoantibodies from the sera of most patients reacted with the retinal proteins of molecular weight between 34 and 40 kDa. The aetiology of this distinctive retinal disorder therefore appears to be mediated through an autoimmune mechanism.

The influence of drinking pattern, at individual and aggregate levels, on alcohol-related negative consequences.

AIM: To determine the extent drinking patterns (at the individual and country level) are associated with alcohol-related consequences over and above the total alcohol the person consumes. METHODS: Hierarchical linear models were estimated based on general population surveys conducted in 18 countries participating in the GENACIS project. RESULTS: In general, the positive association between drinking pattern scores and alcohol-related consequences was found at both the individual and country levels, independent of volume of drinking. In addition, a significant interaction effect indicated that the more detrimental the country's drinking pattern, the less steep the association between the volume of drinking and its consequences. CONCLUSION: Drinking patterns have an independent impact on consequences over and above the relationship between volume and consequences.

Auto- and allopolyploidy in Centaurea sect. Acrocentron s.l. (Asteraceae, Cardueae): karyotype and chromosome banding pattern analyses

Dysploidy and polyploidy are well documented in the large genus Centaurea, especially in sect. Acrocentron and in a small group of species from the Iberian Peninsula described as sect. Chamaecyanus, closely related to Acrocentron. We have explored two interesting cases of polyploid series in both sections: the polyploid series of Centaurea toletana in sect. Chamaecyanus and the series of C. ornata group in sect. Acrocentron. We have carried out a karyological study using both classic karyotype analyses and chromosome banding with fluorochromes.

The "open" chimney graft technique for juxtarenal aortic aneurysms with discrepant renal arteries.

OBJECTIVES: A straightforward original Chimney Graft (CG) protocol has been developed at our institution in selected cases of juxtarenal aortic aneurysm (JRAA). The aim of this study was to present our clinical experience of consecutive series with use of uncovered self-expanding stent (SES) as "Open Chimney" (OCh) in the endovascular repair (EVAR) of JRAA. METHODS: A standard endograft with suprarenal fixation struts is delivered with its proximal covered edge just below the highest RA in JRAA presenting the ostium of the two renal arteries at a different aortic level and the distance between the highest renal artery and the beginning of the aneurysm (improved landing zone) ≥10 mm. The low-lying renal artery is maintained patent by the OCh graft (standard SES) delivered from left brachial access (6 Fr). All clinical, anatomical, and operative data were prospectively collected and retrieved for the study analysis. RESULTS: From July 2010 to November 2012, OCh EVAR was offered to 22 consecutive patients considered unfit for JRAA open repair. All procedures were technically successful with aneurysm exclusion and patent OCh graft. One small perioperative type Ia endoleak spontaneously disappeared at the 3-month CT control. One patient died because of acute decompensated heart failure. One patient presented a left hemispheric stroke. The median follow-up of 18 months (range 7-35) showed aneurysm exclusion in all patients without type I and III endoleaks, SES stenosis, and/or renal impairment. CONCLUSIONS: OCh-EVAR is a straightforward technique that can be employed in selected cases of JRAA, avoiding the more complex and expensive fenestrated EVAR.