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A bonded concrete overlay of asphalt (BCOA), also known as whitetopping, is a thin concrete overlay placed upon a distressed asphalt pavement. The asphalt-resilient modulus is kept constant in current BCOA design procedures. This practice results in an underestimation of the damage as compared to when the hourly temperature variation of the asphalt is considered. The framework to establish an equivalent asphalt modulus involves generating a database of hourly middepth asphalt temperatures. This database should include hourly temperatures for different BCOA structures and a large range of geographical locations representing different climatic conditions. The hourly middepth asphalt temperatures are then used to generate hourly asphalt moduli using master curves. Through fatigue equivalency, the equivalent asphalt moduli are calculated for each month. In order to establish the relationship between the asphalt modulus and middepth temperature, the United States was divided into seven different zones ...

The reasonableness of the models in the Mechanistic-empirical Pavement Design Guide (MEPDG) used to predict the performance of the continuously reinforced concrete pavements (CRCPs) was evaluated in this study. The MEPDG punchout, crack width and spacing and load transfer efficiency (LTE) models were evaluated through a factorial sensitivity study. The input matrix was defined to reflect ‘real-world’ design situations. It was found that, contrary to the 1993 American Association of State Highways and Transportation Officials (AASHTO) Design Guide, crack width must be below 0.5 mm to maintain adequate performance. Additionally, based on the performance predictions from the MEPDG, a crack spacing of less than 1.8 m ensures a crack width of less than 0.5 mm, which is another contradiction with the approach in the 1993 Guide.

This research evaluates the reasonableness of the Mechanistic-Empirical Pavement Design Guide (MEPDG) version 1.0 to predict the joint faulting and transverse cracking of jointed plain concrete pavements (JPCPs). This is accomplished by carrying out a full factorial sensitivity analysis, considering material properties, pavement design features, climates and traffic. This study considers the interaction and correlation between these inputs and was designed to reflect the real conditions that occur in practice. Based on over 3000 runs, the sensitive parameters in the joint faulting model and the transverse cracking model were identified. In general, the analysis indicates JPCP models perform well. However, some counterintuitive results were also found.

The effective linear temperature gradient is a significant input needed to characterize the effects of environmental loadings when available pavement design procedures are used for bonded concrete overlays on asphalt (BCOA), also known as thin or ultrathin whitetopping. Establishing such an input is challenging and therefore has not been well guided in current BCOA design procedures across the country. Guidance is provided on suitable values for the effective equivalent linear temperature gradient (EELTG) that can be used in the design of ultrathin BCOAs. The EELTG is expressed as a function of the climatic conditions, geographical location, and design features of the BCOA: longitude, latitude, elevation, annual mean percentage of sunshine, overlay panel size, 28-day modulus of rupture for the portland cement concrete, and thickness of the hot-mix asphalt layer. Typical values for the annual mean percentage of sunshine are recommended to facilitate implementation of the proposed guideline in the current design procedures.

Slab curvature, which represents the response of concrete pavement slabs to environmental loads, influences the location and magnitude of critical slab stresses and affects long-term pavement performance. The purpose of this study was to measure the changes in temperature and moisture profiles in a newly constructed concrete pavement and to determine both the overall deformed shapes of the slabs as well as the relative contributions of built-in and transient environmental effects over time. Data were collected from an instrumented jointed plain concrete pavement (JPCP) over a 2-year period. Slab curvatures were computed or predicted using measurements of temperature and moisture conditions in the slab, static strain measurements, and pavement surface profile measurements. It was found that the additional restraint provided by the dowel and tie bars does not appear to significantly reduce slab curvature resulting from daily temperature fluctuations or from reversible drying shrinkage. It does have a substa...

This research evaluates the ability of the Mechanistic–Empirical Pavement Design Guide (MEPDG) to accurately predict the performance of jointed plain concrete pavements (JPCPs). This is accomplished by comparing predicted performances with observed performances for the in-service mainline test cells at Mn/ROAD. These comparisons indicate that MEPDG performance predictions for JPCP are most accurate when the default (constant) built-in equivalent temperature difference of − 5.5°C is used instead of a site-dependent value. It appears that significant portions of the error of estimation can be explained by the sensitivity of the performance models to variability in hardened concrete properties (modulus of rupture, modulus of elasticity and coefficient of thermal expansion) and pavement structural features (slab thickness, joint spacing, subbase type and bond condition). Predictions of slab cracking were found to be highly sensitive to these parameters. In addition, the MEPDG cracking model seemed not to fit ...

This paper evaluates the implementation of the built-in temperature difference input parameter in the Mechanistic–Empirical Pavement Design Guide (MEPDG) for the design of jointed plain concrete pavements (JPCPs). The pavement distress, in terms of transverse cracking, is expected to be minimised when the transient temperature difference is equal in magnitude to the built-in temperature difference but of the opposite sign. However, this study shows that a built-in temperature difference of − 6.5°C minimises the cracking prediction for JPCPs. This optimum value of − 6.5°C coincides with the default value in the MEPDG of − 5.5°C, which was established through the nationwide calibration. The cause of this phenomenon is further investigated by taking into account the traffic loading time, slab thickness, joint spacing and reversible shrinkage, but none of these factors are able to explain this anomaly. The results from this study indicate that the built-in gradient should not be an input but is merely a calib...

Hundreds of bonded portland cement concrete (PCC) overlays of hot-mix asphalt (HMA) pavements are being constructed in the United States and around the world. Increasing interest in this rehabilitation method has led to a need to define further the most common forms of distresses, quantify the extent of influence of design parameters on performance, and develop rational design guidelines. This study evaluates the performance of in-service pavements to establish criteria for when reflection cracks might develop. Reflection cracking is dictated by the thickness of the PCC overlay and HMA layer, panel size, climatic conditions, and accumulated vehicle loads. When the relative stiffness of the PCC overlay and HMA layer (defined during the coldest month of the year) falls below the critical value one, reflection cracking develops. The rate of development is a function of the load-related stress in the overlay. The performance analysis of the in-service pavements also verify the benefits of joint sealing and the use of small diameter dowel bars for high volume roadway applications.

The primary objective of this research effort is to determine if temperature gradients affect the ability to use falling weight deflectometer (FWD) testing to monitor pavement joint performance and detect voids under the corners of the slab. A field investigation was performed at the Minnesota Road Research System test facility to meet this objective. It was found that gradients can have an effect on the results of FWD testing for rigid pavements. Although the load transfer efficiencies measured for doweled slabs were not found to be affected by slab temperature or temperature gradients (even when poor joint performance was exhibited), load transfer efficiencies measured for the undoweled slabs were greatly influenced by the presence of a gradient. There even appears to be a higher correlation between the gradient present at the time of testing and the average temperature of the slab for the pavement designs and environmental conditions included in this study. Gradients present at the time of testing also affect the ability to detect voids beneath the slab. Large positive gradients produced negative void parameters (indicating that a void was not present), whereas large negative gradients produced large positive void parameters (indicating that a void was present). This study found that loss of support under the slab could be identified even when the joints were locked if gradients were not present. On the basis of these findings, it is important to determine the complete temperature profile throughout the depth of the slab at the time of testing so that this information can be considered when the deflection data are interpreted.

A numerical approach is presented to simulate the non-Newtonian flow of a wellbore cementing process to quantify the potential for poor drilling mud displacement efficiency and bond strength development between the cement annulus and rock formation. The approach consists of using the lattice Boltzmann method with a Bingham plastic constitutive model to represent the cement flow behavior. The lattice Boltzmann method is a pseudo-particle, mesoscale approach that naturally models complex flows in a computationally efficient manner, but has thus far seen limited use for capturing such slurry (or similar) flows. Results from the model are presented for a wellbore cementing process with various annular configurations and cement slurry properties. In particular, the results consider irregularities and imperfections in the shape of the rock formation surface, as well as changes in the cement flow properties (e.g., viscosity), as could be affected by variations in mix and/or the pumping process. These results show an array of circumstances in which poor drilling mud displacement efficiency and bond strength development between the cement column and rock formation does or does not occur as the cement is pumped into the wellbore annulus. Lastly, potential future work and developments are discussed for the numerical approach to address other failure mechanisms of zonal isolation, which are still poorly understood mechanistically.

A generalized approach for optimal wave propagation-based nondestructive test (NDT) design for potential applications in damage characterization and other characterization problems, is presented and numerically evaluated. More specifically, the objective of this work is to improve the accuracy and efficiency of material characterization processes by optimizing the parameters of the associated NDT, such as the locations of sensors and actuators. The NDT design approach is an extension of prior work to consider wave propagation-based NDT, and is based on maximizing the sensitivity of the NDT response measurements to changes in the material properties to be determined by the evaluation, while simultaneously minimizing the redundancy of response measurements. Two simulated case studies are presented to evaluate the performance of the optimal wave propagation-based NDT design approach. Both examples consider thin plate structures with a damage field that was assumed to be able to be represented by changes in the Young’s modulus distribution throughout the structure. The NDT method considered was based on commonly used ultrasonic testing with piezoelectric sensors and actuators. The Optimal NDT designs corresponding to maximized sensitivity and minimized response redundancy are shown to provide substantially improved evaluation solution efficiency and accuracy for quantitative damage characterization in comparison to more standard NDT designs.

Construction curling and warping produces a built-in gradient, which takes place as the result of changes in temperature and moisture that occur prior to the hardening of Portland cement concrete (PCC) pavements. The slab remains flat in the presence of this gradient because the plastic concrete has not developed sufficient stiffness to generate stress or strain. The new Guide for the Design of New and Rehabilitated Pavement Structures has shown the importance of quantifying the built-in gradient. In this study, the magnitude of the built-in gradient was quantified along with the early-age response of the slab to environmental loads. It was found that the equivalent linear temperature gradient at the time of set was

The focus of this study is to provide a detailed analysis of the strain that develops as a result of environmental loads. The study characterizes slab response immediately after construction (first 72 h after paving) and also addresses seasonal effects over the first 10 months following construction. A heavily instrumented test section was constructed on SR-22 in Murrysville, Pennsylvania, to help characterize slab response to environmental loads better. Static strain and climatic data collected through the first 10 months after construction (August 2004 through June 2005) were analyzed to interpret pavement response to environmental loads as a function of location with respect to joint proximity, depth within the slab, and level of restraint applied to the slab. Many things were also learned about the strain that develops in the slab over the first 10 months after construction. The average strain in the fall was around –450 μstrain, whereas the average strain in the winter was –600 μstrain. The ambient temperatures increased during the spring and summer; this resulted in a decrease in the average strain to –250 μstrain. Thermal strain was found to be twice as high as the drying shrinkage the first winter after construction. A substantial amount of drying shrinkage occurred within the first 50 days after construction. Variations in drying shrinkage occur not only through the depth of the slab but also across the surface of the slab.

The Minnesota Department of Transportation constructed an ultrathin whitetopping (UTW) project at three consecutive intersections on US-169 at Elk River, Minnesota, to gain more experience with both the design and the performance of UTW. Distinct cracking patterns developed within each test section. The UTW test sections with a 1.2- ×1.2-m (4- ×4-ft) joint pattern included corner breaks and transverse cracks. Corner breaks were the primary distress in the test section with a 1.8- ×1.8-m (6- ×6-ft) joint pattern, although very little cracking was exhibited. The Minnesota Road Research Facility UTW test sections on I-94 allow comparisons of the same UTW design on hot-mix asphalt (HMA) pavements with different structural capacities to be made. The strain and deflection measurements emphasize the importance of the support provided by the HMA layer. A reduction in this support occurs when the temperature of the HMA is increased or when the HMA begins to ravel. During evaluations of whether UTW is a viable rehabilitation alternative, cores should be pulled from the pavement to determine if the asphalt is stripping and if the asphalt layer has adequate thickness. UTW can be successfully placed on as little as 76 mm (3 in.) of asphalt, if the quality of the asphalt is good. The cores should also reveal whether the asphalt layer is of uniform thickness and whether stripping and raveling have occurred. If the asphalt layer is of uniform thickness and stripping and raveling have not occurred, UTW is a good option for use in the rehabilitation of asphalt pavements.

Thin and ultrathin whitetopping overlays are becoming a more common method of pavement rehabilitation. It is important to gain information on the types of distresses that occur in the overlays and effective repair techniques. In 1997 the Minnesota Department of Transportation constructed several thin and ultrathin whitetopping test cells at the Minnesota Road Research (Mn/ROAD) facility. Typical distresses included corner breaks, transverse cracks, and reflective cracks. The finite element program ISLAB2000 was used to investigate stress patterns and their relation to the distresses. Different techniques for repairing ultrathin whitetopping were investigated. Various techniques were also used to deter reflective cracking, including various bond-breaking materials and full-depth sawing at strategic locations along the longitudinal joint to prevent cracks from propagating into adjacent panels at misaligned transverse joints. Four of the six sections had present serviceability indexes (PSIs) greater than 3.5 before the repairs, showing that a good level of performance has been maintained after 4.7 million equivalent single-axle loads. The two sections that exhibited the largest drop in PSI were the overlays with 1.2- × 1.2-m (4- × 4-ft) panels. The repairs made in sections containing these panels have brought the PSI back up to an acceptable level (PSI > 3). The thin and ultrathin whitetopping test sections at Mn/ROAD have shown that whitetopping is a viable rehabilitation alternative for asphalt pavements. The importance of choosing an optimum panel size was exhibited. It has also been shown that when necessary, it is easy to repair ultrathin whitetopping sections. Various techniques for repairing each type of distress have been summarized.

Anti-SSA/Ro antibodies are the most prevalent type of antinuclear antibody (ANA). Anti-SSA/ Ro-positive sera may recognise two proteins: a 52 kDa (Ro52) and a 60 kDa (Ro60) subunit. We studied the sensitivity for Ro60 detection using the HEp-2000 substrate, which consists of HEp-2 cells transfected with Ro60 cDNA in an anti-SSA/Ro-positive population consecutively identified by double immunodiffusion (DID) with thymus/spleen nuclear extract and line immunoassay (LIA) with recombinant Ro52 and Ro60. One hundred and twenty-seven consecutive anti-SSA/Ro-positive sera defined by DID with thymus/spleen nuclear extract and LIA using recombinant Ro52 and Ro60 were analysed on HEp-2000 and DID with natural Ro60. Of these, 91 were anti-Ro60 positive on LIA and/ or DID with natural Ro60. The HEp-2000 substrate detected 70/91 (sensitivity 77%) and correlated strongest with DID. Most of the missed anti-Ro60-positive sera had high ANA intensity. The substrate did not detect monospecific anti-Ro52 antibodies (sensitivity 9.7%; 3/31). HEp-2000 substrate can therefore be considered a reliable, simple and alternative method for DID in the detection of anti-Ro60 reactivity. Special follow-up should be given to sera with strong ANA patterns in which the SSA/Ro60 staining pattern may be hidden.

The volumetric surface texture (VST) test was developed at the University of Minnesota to provide an estimate of the load transfer potential available through aggregate interlock across a concrete fracture plane. It can also provide an estimate of the abrasion that has taken place since fracture. A study was undertaken to validate the VST concept and test procedures. The factors investigated in this study include the effects of aggregate characteristics on measured surface texture and the effects of measured surface texture on crack and undoweled joint performance, as indicated by deflection-based load transfer efficiency. Deflection, load, and crack width data were collected for both field and laboratory slabs, and VST testing was performed with companion specimens for these slabs. This study has shown that the VST test provides a means of accurately measuring surface texture so that the selection of concrete aggregates can be performed with consideration of potential aggregate interlock at cracks and undoweled joints. Performance prediction equations were developed to provide an early indication of how cracks and undoweled joints will perform before a particular aggregate size, type, gradation, or blend is used in an actual pavement.

State highway agencies in Connecticut, Kansas, Minnesota, Wisconsin, and Wyoming have successfully designed and constructed rigid pavements containing recycled concrete aggregate (RCA). Success has been attributed in part to the minimization of old mortar content in the RCA during recycling processes, thereby controlling the total mortar content of the new portland cement concrete (PCC) mixture, or to the achievement of higher-than-expected compressive strengths through adjustments in mix proportions, or both. There was no clear correlation between mortar content and cracking distresses in field investigations, although one project did exhibit significantly more slab cracking in the recycled pavement than in the corresponding control pavement. The increased cracking may have been due to the large differences in total mortar content between the recycled and control sections. In general, the recycled PCC pavements considered in this study have performed comparably with their conventional PCC pavement counterparts, including the recycled pavements that incorporated RCA derived from concrete affected by D-cracking and alkali-silica reactivity (ASR). There is, however, evidence of small amounts of localized recurrent ASR in the recycled Wyoming pavement. Whether this reactivity will eventually develop into widespread distress remains to be seen.

Composite pavements have proved in Europe and the United States to have long service life with excellent surface characteristics, structural capacity, and rapid renewal when needed. This project developed the guidance needed to design and construct new composite pavement systems. Volume 1 presents the state of the practice and guidelines for designing and constructing new hot-mix asphalt (HMA) concrete over a portland cement concrete (PCC) composite pavement that takes full advantage of using differing materials. Volume 2 provides guidance on the design and construction of two-layer, wet-on-wet PCC pavements where the upper layer is a thin high-quality layer (hard nonpolishing aggregate, higher cement content, higher quality binder) and excellent surface characteristics with the lower layer containing a higher percentage of local aggregates and recycled materials. Both volumes detail performance data on existing composite pavement systems and provide step-by-step guidance on the design of composite pavements using mechanistic-empirical design methods for both types of new composite pavements.

Fracturing Hydrology? Hydraulic fracturing, widely known as "fracking," is a relatively inexpensive way to tap into what were previously inaccessible natural gas resources. Vidic et al. (p. 826 ) review the current status of shale gas development and discuss the possible threats to water resources. In one of the hotbeds of fracking activity, the Marcellus Shale in the eastern United States, there is little evidence that additives have directly entered groundwater supplies, but the risk remains. Ensuring access to monitoring data is an important first step toward addressing any public and environmental health concerns.

This work describes the development of an environmental friendly functionalized polypropylene nonwoven geotextile (PP) in order to trap heavy metals in sediments and sludges. Chitosan was chosen as the sorbent because of its ability to trap heavy metals, of its natural origin (from shells), and of its low cost. PP was first functionalized with acrylic acid using a cold plasma process, in order to bring some reactive carboxylic functions onto the surface. Chitosan was then covalently grafted on the acrylic acid modified polypropylene. The functionalized surfaces were characterized by FTIR (Fourier Transform InfraRed) and chitosan was thus proven to be grafted. The ability of the functionalized textile to trap heavy metals was then investigated. Copper was chosen as the model heavy metal, and artificial solutions of CuSO4 were prepared for the experiments. Sorption studies among the concentration of copper in polluted solutions at 20°C were carried out with PP-g-AA-chitosan (Polypropylene-grafted-Acrylic acid-chitosan) in order to evaluate the maximum of absorption of this surface: the textile can chelate copper increasingly with the initial copper concentration until 800 ppm where it reaches a plateau at about 30 mg/L. The effects of pH and of the ionic strength (absorption in a NaCl containing solution) were finally investigated. The trapping of Cu 2+ decreases slowly when the ionic strength increases. For a seawater-like NaCl concentration of 30g/L, the textile still chelates about 20 mg/L of Cu 2+ . Finally, the optimum pH to trap the maximum amount of copper was determined to be 4.75, which corresponds to the optimum pH for the solubility of the chitosan.

We describe a nondestructive evaluation (NDE) method based on the propagation of highly nonlinear solitary waves (HNSWs) to determine the excess of water on the surface of existing concrete structures. HNSWs are induced in a one-dimensional granular chain placed in contact with the concrete to be tested. The chain is part of a built-in transducer designed and assembled to exploit the dynamic interaction between the particles and the concrete. The hypothesis is that the interaction depends on the stiffness of the concrete and influences the time-of-flight of the solitary pulse reflected at the transducer/concrete interface. Two sets of experiments were conducted. In the first set, eighteen concrete cylinders with different water-to-cement (w/c) ratios were cast and tested in order to obtain baseline data to link the ratio to the time of flight. Then, sixteen short beams with fixed w/c ratio, but subject to water in excess at one surface, were cast. The novel NDE method was applied along with the conventional ultrasonic pulse velocity technique in order to determine advantages and limitations of the proposed approach. The results show that the time of flight detected the excess of water in the beams. In the future, the proposed method may be employed in the field to evaluate rapidly and reliably the condition of existing concrete structures and, in particular, concrete decks.

This paper describes the application of a novel actuator/sensor technology for monitoring concrete at early age. A device is designed to generate and detect highly nonlinear solitary waves (HNSWs) in a chain of steel beads. Two experiments were conducted. In the first experiment, the propagation of the HNSWs in the chain was recorded. In particular, the reflections at the interface between the chain and a composite layer consisting of a thin aluminum plate and the concrete were observed. It was found that the travelling time of HNSWs of the reflected pulses depend on the boundary conditions of the chain, so it changes as the stiffness and strength of concrete develop during the hydration process. In the second experiment, a similar actuator was used to transmit mechanical waves inside concrete. These waves were then detected by an embedded commercial transducer. The change of frequency components of the stress waves in the fresh concrete was monitored and used to interpret the initial set of the concrete. The results of these two experiments were compared to outcomes of the penetration resistance test (ASTM C403) conventionally used to determine the time of setting. We found that the proposed nondestructive evaluation method can be used in fresh concrete although more tests are needed to prove repeatability under various concrete mixtures.

Endoscopic correction of vesicoureteric reflux in children has been performed in several hundred cases with the use of Teflon or cross-linked bovine collagen. The main criticism to this simple procedure is the potential migration of Teflon particles and the local pathological reaction. An experimental study was performed in 20 rabbits injected with Teflon or collagen in the bladder submucosa. A pathological examination of the bladder, lymph nodes, liver, lungs and brain was performed several months after the experiment to study the migration and the local reaction. There is no local granulomatous reaction with collagen while a local granulomatous reaction is found in the site of injection of Teflon and in 1 locoregional lymph node. The colonization of collagen by histiocytes increases with time. No distant granulomatous reaction was noted with both injections on histological examination. A mineralogic technique was applied after homogenisation of the lungs and brain to further investigate the distant migration problem. Rare particles of Teflon were observed in the lungs but not in the brain. The pathological significance of these particles remains unclear, but calls for research for different injection materials.

Abstract This paper broadly discusses the design considerations particular to the large diameter export steel catenary riser (SCR) systems for the Holstein and Mad Dog Spar Buoy facilities. It also focuses on fatigue phenomena that are a challenge, but essential, to quantify to ensure feasibility and delivery of an optimized design solution. Introduction BP and its partners are developing several deepwater prospects in the Gulf of Mexico. These include the Holstein, Mad Dog, Thunder Horse and Atlantis floating production facilities in water depths ranging from 4500 feet to 7300 feet. Oil and gas will be exported via the Mardi Gras Transportation System, the deepwater segment of which consists of 16-inch to 28-inch oil and gas pipelines, steel catenary risers, and subsea wyes for current and future tie-ins. The focus of this paper is the export riser systems supported by the Holstein and Mad Dog Spar Buoy platform structures. Each facility has two SCRs; the diameters of which are 24-inch (Oil, Caesar export system) and 16-inch (Gas, Cleopatra export system). This paper discusses the effect of combining the predicted fatigue damage for these large diameter risers, as well as understanding how riser routing impacts and is impacted by vessel motions, to establish the optimum location for attaching the SCRs near the keel line of the Spar. This is not the standard hang off location of an SCR, as it incurs a significant increase in complexity of the system installation. Nevertheless, it was essential for Holstein and Mad Dog to achieve a feasible large diameter export riser system. At this hang off location, the vessel motions that dominate fatigue are different from those that traditionally induce the highest damage to the riser. To resolve these fatigue issues required an iterative interactive process between the riser and vessel design teams to optimize the hull motions to minimize damage. This process was a requisite, not only to optimize the design solution, but also to deliver a feasible system configuration. Holstein and Mad Dog System Description The Holstein and Mad Dog facilities are located in Green Canyon blocks GC 645 and GC 782 respectively in a water depth of approximately 4400 feet. The Holstein and Mad Dog facilities are some of the largest Spars that have been built to date, with the Holstein spar being the largest, with a total length of 746 feet and diameter of 150 feet. Both Spars are a truss type, characterized by a large cylindrical buoyant hard tank penetrating the sea surface, below this is an open truss type structure terminating at the vessel keel with a smaller buoyant soft tank. The export systems depart the facilities in a northeasterly direction. Figure 1 shows a plan view of the two facilities, the export risers and associated Caesar and Cleopatra export pipeline routes in the immediate vicinity. A more detailed summary of the Spars and riser configuration is captured in Table 1, which lists the key spar configurations and Figure 2, which shows a typical general arrangement of an export SCR.

A fast immunoblotting procedure, termed "microgel diffusion blotting," is used to detect and identify antibodies to extractable nuclear antigens (i.e., to Sm, RNP, and SSB) in patients with rheumatic diseases. The method differs from the standard immunoblotting techniques by the use of ultra-thin microgels for polyacrylamide gel electrophoresis: the very thin gel layer allows transfer of proteins to a nitrocellulose membrane by simple diffusion. Principal advantages of this variant technique are its simplicity, rapidity, and reproducibility--characteristics that make the test suitable for routine application. We compared the sensitivity of the test with that of double immunodiffusion in agarose for the evaluation of humoral antinuclear immunity. Microgel diffusion blotting detected antibodies in serum at concentrations less than 0.001 of those detectable by immunodiffusion.

There is an increasing use in the pharmaceutical industry of barrier systems such as transfer isolators, sterilisation tunnels and work station isolators. As Vapor Hydrogen Peroxide (VHP) sterilisation of isolators and lyophilizers becomes an important sterilisation method, there is an acute need for a VHP monitoring system to be used for in-process control and validation. In this study, near infrared (NIR) spectrofotometry was evaluated as a potential technique to monitor hydrogen peroxide. Additionally the H2O2 vapor permeability of different packaging materials, commonly used in steam and ethylene oxide sterilisation, was evaluated.NIR spectrofotometry, using a gas cell connected with optic fibres, was evaluated as a potential technique to monitor hydrogen peroxide vapor and water vapor during VHP sterilisation of an isolator. A NIR spectrum was taken every 30 s during VHP sterilisation of an isolator. The influence of injection rate, air flow rate, working temperature and gas distribution was investigated. The H2O2 vapor permeability of different packaging materials was determined by placing the gas cell in the sterilisation bags and sealing the bags hermetically. The sterilisation bag was then subjected to VHP sterilisation.The NIR spectra taken at steady state sterilization conditions showed 4 absorption peaks: at 1364, 1378 and 1400 nm attributed to water and at 1420 nm attributed to H2O2 vapor. By measuring the absorbance level at these wavelengths, the actual concentration of H2O and H2O2 vapor in the isolator was calculated. The water vapor permeation of the sterilisation bags, measured with NIR, appeared to be equal for all materials tested. Whereas Tyvek was the most permeable material for hydrogen peroxide vapor (82.7% of the reference concentration outside the bag), only 30% was found in bags made of medical paper. Sterilisation bags consisting of laminate films and PVC sealed to medical paper showed intermediate permeability.Near-infrared (NIR) spectroscopy using a gas cell with optic fibres is a useful technique to monitor VHP sterilisation cycles. There was a difference in H2O2 vapor permeability of different packaging materials, commonly used in steam and ethylene oxide sterilisation.

Mouse and dog epithelial cell lines, expressing high levels of the Ca(2+)-dependent cell-cell adhesion molecule E-cadherin in vitro, generated invasive and metastatic tumors in athymic mice. From these tumors, neoplastic cell lines were isolated. All ex vivo isolates retained high expression levels of E-cadherin at their surface. Nevertheless, some showed a fusiform morphotype, were defective in Ca(2+)-dependent cell aggregation, and were invasive in vitro, indicating that E-cadherin was not functional. Cell-associated proteoglycans were found to be enlarged in these variants as compared to their counterparts with functional E-cadherin. Treatment of the cells with the drug 4-methylumbelliferyl beta-D-xyloside specifically reduced the amount and size of cell-associated proteoglycans. This same drug induced an epithelial morphotype, increased Ca(2+)- and E-cadherin-dependent cell aggregation, and abrogated invasiveness without influencing E-cadherin expression levels. Our results indicate that enlarged proteoglycans can prevent the homophilic binding of E-cadherin, probably by steric hindrance. This is one more mechanism by which carcinomas may counteract invasion-suppressor genes and acquire malignancy.

The occurrence of antinuclear antibodies (ANA) in the serum of 485 healthy volunteer blood donors was assessed. Sixty two sera displayed nuclear immunofluorescence staining on Hep-2 cells using a polyvalent anti-Ig conjugate. In general, the titer of these antibodies was low (42/62 sera displaying a titer lower than or equal to 1:80). In only 23 sera were the ANA of the IgG isotype, which is the more disease-related immunoglobulin class of autoantibodies. In order to define the frequency of antibodies to extractable nuclear antigens and dsDNA within this population, sera were further analyzed by counterimmunoelectrophoresis. Western blot and the Crithidia luciliae assay. One serum displayed weak antids DNA reactivity; another serum had anti-SSA/Ro activity. On Western blot several patterns were found. They could not be identified with any of the available reference antisera.

Over 2 years, 191 patients with symptomatic benign prostatic hypertrophy (BPH) have been treated by transurethral radiofrequency heating of the prostate at various temperatures (44.5 and 47-48 degrees C) in one session. At 44.5 degrees C, 60% of the patients were subjectively improved and 71% at 47-48 degrees C. 58% of the patients in retention were catheter free after treatment. The mean increase in the peak flow was not significant no matter the temperature used. A subjective improvement is obviously demonstrated by the significant decrease in the overall symptom score and essentially by the reduction in the irritative symptoms such as nocturia and urgency. This new alternative approach may play a meaningful role in the symptomatic management of selected patients with BPH.

In 2 years, 191 patients with symptomatic benign prostatic hypertrophy (BPH) were treated by transurethral radiofrequency heating of the prostate at various temperatures (44.5 and 47-48 degrees C) in one session. At 44.5 degrees C, 60% of the patients were subjectively improved and 71% at 47-48 degrees C. 58% of the patients in retention were catheter free after treatment. The mean increase in the peak flow was not significant in spite of the temperature used. A subjective improvement is obviously demonstrated by the significant decrease in the overall symptom score and essentially by the reduction in the irritative symptoms such as nocturia and urgency. This new alternative approach may play a meaningful role in the symptomatic management of selected patients with BPH.

The bioavailability and pharmacokinetics of ibuprofen, a nonsteroidal antiinflammatory drug, was studied in healthy Shetland ponies. Ibuprofen was administered IV, as a suspension, and as a solid solution oral paste to ponies from which food was withheld. The suspension paste was also administered to ponies that received hay and water ad libitum. Both formulations had an absolute bioavailability of about 80%. Bioavailability was not influenced by feeding.

One case of penile verrucous carcinoma (Buschke-Lowenstein tumor) undergoing anaplastic transformation and containing human papillomavirus type 6 is presented. The viral genome is detected by in situ hybridization using biotin-labeled cDNA probes. The clinical, histological and virologic criteria of verrucous carcinoma are discussed in comparison to giant condyloma and highly differentiated squamous cell carcinoma. The importance of viral typing determination for further diagnostic and therapeutic procedures is emphasized.

A fast immunoblotting procedure, termed "microgel diffusion blotting," is used to detect and identify antibodies to extractable nuclear antigens (i.e., to Sm, RNP, and SSB) in patients with rheumatic diseases. The method differs from the standard immunoblotting techniques by the use of ultra-thin microgels for polyacrylamide gel electrophoresis: the very thin gel layer allows transfer of proteins to a nitrocellulose membrane by simple diffusion. Principal advantages of this variant technique are its simplicity, rapidity, and reproducibility--characteristics that make the test suitable for routine application. We compared the sensitivity of the test with that of double immunodiffusion in agarose for the evaluation of humoral antinuclear immunity. Microgel diffusion blotting detected antibodies in serum at concentrations less than 0.001 of those detectable by immunodiffusion.