Preoperative percutaneous portal vein embolization: evaluation of adverse events in 188 patients.

PURPOSE: To retrospectively assess the frequency of adverse events related to percutaneous preoperative portal vein embolization (PPVE). MATERIALS AND METHODS: Institutional review board did not require its approval or patient informed consent for this study. The adverse events that occurred during PPVE or until planned hepatic surgery was performed or cancelled were retrospectively obtained from clinical, imaging, and laboratory data files in 188 patients (109 male and 79 female patients; mean age, 60 years; range, 16-78 years). Liver resection was planned for metastases (n = 137), hepatocarcinoma (n = 31), cholangiocarcinoma (n = 15), fibrolamellar hepatoma (n = 1), and benign disease (n = 4). PPVE was performed with a single-lumen 5-F catheter and a contralateral approach with n-butyl cyanoacrylate mixed with iodized oil as the main embolic agent. The rate of complications in patients with cirrhosis was compared with that in patients without cirrhosis by using the chi(2) test. RESULTS: Adverse events occurred in 24 (12.8%) of 188 patients, including 12 complications and 12 incidental imaging findings. Complications included thrombosis of the portal vein feeding the future remnant liver (n = 1); migration of emboli in the portal vein feeding the future remnant liver, which necessitated angioplasty (n = 2); hemoperitoneum (n = 1); rupture of a metastasis in the gallbladder (n = 1); transitory hemobilia (n = 1); and transient liver failure (n = 6). Incidental findings were migration of small emboli in nontargeted portal branches (n = 10) and subcapsular hematoma (n = 2). Among the 187 patients in whom PPVE was technically successful, there was a significant difference (P < .001) between the occurrence of liver failure after PPVE in patients with cirrhosis (five of 30) and those without (one of 157). Sixteen liver resections were cancelled due to cancer progression (n = 12), insufficient hypertrophy of the nonembolized liver (n = 3), and complete portal thrombosis (n = 1). CONCLUSION: PPVE is a safe adjuvant technique for hypertrophy of the initially insufficient liver reserve. Post-PPVE transient liver failure is more common in patients with cirrhosis than in those without cirrhosis.

Benchmarking therapeutic drug monitoring software: A systematic evaluation of available computer tools

Introduction: Therapeutic drug monitoring (TDM) aims at optimizing treatment by individualizing dosage regimen based on measurement of blood concentrations. Maintaining concentrations within a target range requires pharmacokinetic and clinical capabilities. Bayesian calculation represents a gold standard in TDM approach but requires computing assistance. In the last decades computer programs have been developed to assist clinicians in this assignment. The aim of this benchmarking was to assess and compare computer tools designed to support TDM clinical activities.¦Method: Literature and Internet search was performed to identify software. All programs were tested on common personal computer. Each program was scored against a standardized grid covering pharmacokinetic relevance, user-friendliness, computing aspects, interfacing, and storage. A weighting factor was applied to each criterion of the grid to consider its relative importance. To assess the robustness of the software, six representative clinical vignettes were also processed through all of them.¦Results: 12 software tools were identified, tested and ranked. It represents a comprehensive review of the available software's characteristics. Numbers of drugs handled vary widely and 8 programs offer the ability to the user to add its own drug model. 10 computer programs are able to compute Bayesian dosage adaptation based on a blood concentration (a posteriori adjustment) while 9 are also able to suggest a priori dosage regimen (prior to any blood concentration measurement), based on individual patient covariates, such as age, gender, weight. Among those applying Bayesian analysis, one uses the non-parametric approach. The top 2 software emerging from this benchmark are MwPharm and TCIWorks. Other programs evaluated have also a good potential but are less sophisticated (e.g. in terms of storage or report generation) or less user-friendly.¦Conclusion: Whereas 2 integrated programs are at the top of the ranked listed, such complex tools would possibly not fit all institutions, and each software tool must be regarded with respect to individual needs of hospitals or clinicians. Interest in computing tool to support therapeutic monitoring is still growing. Although developers put efforts into it the last years, there is still room for improvement, especially in terms of institutional information system interfacing, user-friendliness, capacity of data storage and report generation.

Benchmarking therapeutic drug monitoring software: A systematic evaluation of available computer tools

Objectives: Therapeutic drug monitoring (TDM) aims at optimizing treatment by individualizing dosage regimen based on blood concentrations measurement. Maintaining concentrations within a target range requires pharmacokinetic (PK) and clinical capabilities. Bayesian calculation represents a gold standard in TDM approach but requires computing assistance. The aim of this benchmarking was to assess and compare computer tools designed to support TDM clinical activities.¦Methods: Literature and Internet were searched to identify software. Each program was scored against a standardized grid covering pharmacokinetic relevance, user-friendliness, computing aspects, interfacing, and storage. A weighting factor was applied to each criterion of the grid to consider its relative importance. To assess the robustness of the software, six representative clinical vignettes were also processed through all of them.¦Results: 12 software tools were identified, tested and ranked. It represents a comprehensive review of the available software characteristics. Numbers of drugs handled vary from 2 to more than 180, and integration of different population types is available for some programs. Nevertheless, 8 programs offer the ability to add new drug models based on population PK data. 10 computer tools incorporate Bayesian computation to predict dosage regimen (individual parameters are calculated based on population PK models). All of them are able to compute Bayesian a posteriori dosage adaptation based on a blood concentration while 9 are also able to suggest a priori dosage regimen, only based on individual patient covariates. Among those applying Bayesian analysis, MM-USC*PACK uses a non-parametric approach. The top 2 programs emerging from this benchmark are MwPharm and TCIWorks. Others programs evaluated have also a good potential but are less sophisticated or less user-friendly.¦Conclusions: Whereas 2 software packages are ranked at the top of the list, such complex tools would possibly not fit all institutions, and each program must be regarded with respect to individual needs of hospitals or clinicians. Programs should be easy and fast for routine activities, including for non-experienced users. Although interest in TDM tools is growing and efforts were put into it in the last years, there is still room for improvement, especially in terms of institutional information system interfacing, user-friendliness, capability of data storage and automated report generation.

New perspectives in the use of ink evidence in forensic science : part III : operational applications and evaluation

The research reported in this series of article aimed at (1) automating the search of questioned ink specimens in ink reference collections and (2) at evaluating the strength of ink evidence in a transparent and balanced manner. These aims require that ink samples are analysed in an accurate and reproducible way and that they are compared in an objective and automated way. This latter requirement is due to the large number of comparisons that are necessary in both scenarios. A research programme was designed to (a) develop a standard methodology for analysing ink samples in a reproducible way, (b) comparing automatically and objectively ink samples and (c) evaluate the proposed methodology in forensic contexts. This report focuses on the last of the three stages of the research programme. The calibration and acquisition process and the mathematical comparison algorithms were described in previous papers [C. Neumann, P. Margot, New perspectives in the use of ink evidence in forensic science-Part I: Development of a quality assurance process for forensic ink analysis by HPTLC, Forensic Sci. Int. 185 (2009) 29-37; C. Neumann, P. Margot, New perspectives in the use of ink evidence in forensic science-Part II: Development and testing of mathematical algorithms for the automatic comparison of ink samples analysed by HPTLC, Forensic Sci. Int. 185 (2009) 38-50]. In this paper, the benefits and challenges of the proposed concepts are tested in two forensic contexts: (1) ink identification and (2) ink evidential value assessment. The results show that different algorithms are better suited for different tasks. This research shows that it is possible to build digital ink libraries using the most commonly used ink analytical technique, i.e. high-performance thin layer chromatography, despite its reputation of lacking reproducibility. More importantly, it is possible to assign evidential value to ink evidence in a transparent way using a probabilistic model. It is therefore possible to move away from the traditional subjective approach, which is entirely based on experts' opinion, and which is usually not very informative. While there is room for the improvement, this report demonstrates the significant gains obtained over the traditional subjective approach for the search of ink specimens in ink databases, and the interpretation of their evidential value.

Deicer Scaling Resistance of Concrete Mixtures Containing Slag Cement Phase 2: Evaluation of Different Laboratory Scaling Test Methods, TPF-5(100), 2012

With the use of supplementary cementing materials (SCMs) in concrete mixtures, salt scaling tests such as ASTM C672 have been found to be overly aggressive and do correlate well with field scaling performance. The reasons for this are thought to be because at high replacement levels, SCM mixtures can take longer to set and to develop their properties: neither of these factors is taken into account in the standard laboratory finishing and curing procedures. As a result, these variables were studied as well as a modified scaling test, based on the Quebec BNQ scaling test that had shown promise in other research. The experimental research focused on the evaluation of three scaling resistance tests, including the ASTM C672 test with normal curing as well as an accelerated curing regime used by VDOT for ASTM C1202 rapid chloride permeability tests and now included as an option in ASTM C1202. As well, several variations on the proposed draft ASTM WK9367 deicer scaling resistance test, based on the Quebec Ministry of Transportation BNQ test method, were evaluated for concretes containing varying amounts of slag cement. A total of 16 concrete mixtures were studied using both high alkali cement and low alkali cement, Grade 100 slag and Grade 120 slag with 0, 20, 35 and 50 percent slag replacement by mass of total cementing materials. Vinsol resin was used as the primary air entrainer and Micro Air® was used in two replicate mixes for comparison. Based on the results of this study, a draft alternative test method to ASTM C762 is proposed.

Assessment of Weathering Steel Bridge Performance in Iowa and Development of Inspection and Maintenance Techniques, RB17-012, 2013

Weathering steel is commonly used as a cost-effective alternative for bridge superstructures, as the costs and environmental impacts associated with the maintenance/replacement of paint coatings are theoretically eliminated. The performance of weathering steel depends on the proper formation of a surface patina, which consists of a dense layer of corrosion product used to protect the steel from further atmospheric corrosion. The development of the weathering steel patina may be hindered by environmental factors such as humid environments, wetting/drying cycles, sheltering, exposure to de-icing chlorides, and design details that permit water to pond on steel surfaces. Weathering steel bridges constructed over or adjacent to other roadways could be subjected to sufficient salt spray that would impede the development of an adequate patina. Addressing areas of corrosion on a weathering steel bridge superstructure where a protective patina has not formed is often costly and negates the anticipated cost savings for this type of steel superstructure. Early detection of weathering steel corrosion is important to extending the service life of the bridge structure; however, written inspection procedures are not available for inspectors to evaluate the performance or quality of the patina. This project focused on the evaluation of weathering steel bridge structures, including possible methods to assess the quality of the weathering steel patina and to properly maintain the quality of the patina. The objectives of this project are summarized as follows:  Identify weathering steel bridge structures that would be most vulnerable to chloride contamination, based on location, exposure, environment, and other factors.  Identify locations on an individual weathering steel bridge structure that would be most susceptible to chloride contamination, such as below joints, splash/spray zones, and areas of ponding water or debris.  Identify possible testing methods and/or inspection techniques for inspectors to evaluate the quality of the weathering steel patina at locations discussed above.  Identify possible methods to measure and evaluate the level of chloride contamination at the locations discussed above.  Evaluate the effectiveness of water washing on removing chlorides from the weathering steel patina.  Develop a general prioritization for the washing of bridge structures based on the structure’s location, environment, inspection observations, patina evaluation findings, and chloride test results.

Analysis of Existing Work-Zone Devices with MASH Safety Performance Criteria, TPF-5(018), 2009

Crashworthy, work-zone, portable sign support systems accepted under NCHRP Report No. 350 were analyzed to predict their safety peformance according to the TL-3 MASH evaluation criteria. An analysis was conducted to determine which hardware parameters of sign support systems would likely contribute to the safety performance with MASH. The acuracy of the method was evaluated through full-scale crash testing. Four full-scale crash tests were conducted with a pickup truck. Two tall-mounted, sign support systems with aluminum sign panels failed the MASH criteria due to windshield penetration. One low-mounted system with a vinyl, roll-up sign panel failed the MASH criteria due to windshield and floorboard penetration. Another low-mounted system with an aluminum sign panel successfully met the MASH criteria. Four full-scale crash tests were conducted with a small passenger car. The low-mounted tripod system with an aluminum sign panel failed the MASH criteria due to windshield penetration. One low-mounted system with aluminum sign panel failed the MASH criteria due to excessive windshield deformation, and another similar system passed the MASH criteria. The low-mounted system with a vinyl, roll-up sign panel successfully met the MASH criteria. Hardware parameters of work-zone sign support systems that were determined to be important for failure with MASH include sign panel material, the height to the top of the mast, the presence of flags, sign-locking mechanism, base layout and system orientation. Flowcharts were provided to assist manufacturers when designing new sign support systems.

Laboratory Evaluation of Asphalt-Rubber in Asphalt Paving Mixture, MLR-89-15, 1990

Interest in the use of ground rubber from used tires as a hot asphalt mix binder has been increasing due to the magnitude of the disposal problem posed by the annual addition of millions of waste tires to the refuse stream. This study evaluates, through laboratory means, the performance of asphalt-rubber as a hot mix binder as compared to conventional asphalt. The results indicate that asphalt-rubber outperforms its base asphalt in mixes of identical gradation and comparable void content on tests that are heavily dependent on binder characteristics (resilient modulus and indirect tension). An appreciable increase in rut resistance due to the use of asphalt-rubber is not indicated.

Production and Evaluation of Calcium Magnesium Acetate, HR-243, 1982

Calcium magnesium acetate (CMA) has been identified by Bjorksten Research Laboratories as an environmentally harmless alternative to sodium or calcium chloride for deicing highways. Their study found CMA to be noncorrosive to steel, aluminum and zinc with little or no anticipated environmental impact. When used, it degrades into elements found in abundance in nature. The deicing capabilities were found to be similar to sodium chloride. The neutralized CMA they produced did cause scaling of PC concrete, but they did not expect mildly alkaline CMA to have this effect. In the initial investigation of CMA at the Iowa DOT laboratory, it was found that CMA produced from hydrated lime and acetic acid was a light, fluffy material. It was recognized that a deicer in this form would be difficult to effectively distribute on highways without considerable wind loss. A process was developed to produce CMA in the presence of sand to increase particle weight. In this report the product of this process, which consists of sand particles coated with CMA, is referred to as "CMA deicer". The mixture of salts, calcium magnesium acetate, is referred to as "CMA". The major problems with CMA for deicing are: (1) it is not commercially available, (2) it is expensive with present production methods and (3) there is very little known about how it performs on highways under actual deicing conditions. In view of the potential benefits this material offers, it is highly desirable to find solutions or answers to these problems. This study provides information to advance that effort. The study consisted of four principal tasks which were: 1. Production of CMA Deicer The objective was to further develop the laboratory process for producing CMA deicer on a pilot plant basis and to produce a sufficient quantity for field trials. The original proposal called for producing 20 tons of CMA deicer. 2. Field Evaluation of CMA Deicer The objective was to evaluate the effectiveness of CMA deicer when used under field conditions and obtain information on application procedures. Performance was compared with a regular 50/50 mixture of sand and sodium chloride. 3. Investigation of Effects of CMA on PC Concrete The objective was to determine any scaling effect that mildly alkaline CMA might have on PC concrete. Comparison was made with calcium chloride. 4. Determine Feasibility of Producing High Magnesium CMA The objective was to investigate the possibility of producing a CMA deicer with magnesium acetate content well above that produced from dolomitic lime. A high magnesium acetate content is desirable because pure magnesium acetate has a water eutectic of -22 F° as compared with +5 F° for calcium acetate and is therefore a more effective deicer.

Field Demonstration and Laboratory Evaluation of Foamed Asphalts - Muscatine County, HR-233, 1985

In view of the energy, environmental, and economic advantages of the foamed asphalt process using local aggregates in cold mixes and the promising results from Research Project HR-212, a 4.2-mile section of county road in Muscatine County was built with foamed asphalt and local aggregates during August-September 1983. Extensive laboratory evaluation was carried out on five plant mixes representing foamed mixes used in the nine test sections, a laboratory prepared foamed mix, and a laboratory prepared hot mix similar to Plant Mix 1. The foamed mixes were compacted, cured under 15 curing conditions and tested for bulk specific gravity, Marshall stability at 77° F and at 140° F, cured moisture content, resilient modulus and effects of moisture damage due to freeze-thaw cycles, water soaking, and vacuum saturation. In addition, four sets of 83 core samples were taken at 1 to 15 months and tested for moisture content, specific gravity, Marshall stability, and resilient modulus. In summary, the test road has performed satisfactorily for almost two years. The few early construction problems encountered were to be expected for experimental projects dealing with new materials and technologies. Overall results to date are encouraging and foamed asphalt mixes have proved to have the potential as a viable base material in areas where marginal aggregates are available. It is hoped and expected that performance evaluation of the test sections will be continued and that more foamed asphalt trial projects will be constructed and monitored so that experiences and findings from this project can be verified and mix design criteria can be gradually established. For future foamed asphalt projects it is recommended that anti-stripping additives, such as hydrated lime, be added in view of the potential moisture susceptibility of foamed mixes observed in the laboratory evaluation.

Evaluation of Preformed Neoprene Joint Seals, HR-318, 1994

Most pavement contraction joint seals in Iowa, in general, have been performing in less than a satisfactory manner. The effective life of the seals, in maintaining a watertight joint, has been only from two to five years. In search of improvements, research was proposed to evaluate preformed neoprene joint seals. The performance of those seals was to be compared mainly with the hot poured rubberized asphalt sealants and cold applied silicone sealants or other sealants commonly used at the time this research began. Joint designs and methods of sawing were also investigated. All evaluations were done in new portland cement concrete (PCC) pavements. Three projects were initially selected and each included a research section of joint sealing. Some additional sites were later added for evaluation. Several joint sealants were evaluated at each research site. The various sites included high, medium and low levels of traffic. Evaluations were done over a five-year period. Neoprene joint seals provided better performance than hot or cold field formed joints.

Evaluation of Carbonate Aggregate Using X-Ray Analysis, HR-266, 1989

Iowa has more than 13,000 miles of portland cement concrete (PCC) pavement. Some pavements have performed well for over 50 years, while others have been removed or overlaid due to the premature deterioration of joints and cracks. Some of the premature deterioration is classical D-cracking, which is attributed to a critically saturated aggregate pore system (freeze-thaw damage). However, some of the premature deterioration is related to adverse chemical reactivity involving carbonate coarse aggregate. The objective of this paper is to demonstrate the value of a chemical analysis of carbonate aggregate using X-ray equipment to identify good or poor quality. At least 1.5% dolomite is necessary in a carbonate aggregate to produce a discernible dolomite peak. The shift of the maximum-intensity X-ray diffraction dolomite d-spacing can be used to predict poor performance of a carbonate aggregate in PCC. A limestone aggregate with a low percentage of strontium (less than 0.013) and phosphorus (less than 0.010) would be expected to give good performance in PCC pavement. Poor performance in PCC pavement is expected from limestone aggregates with higher percentages (above 0.05) of strontium.

Evaluation of the Video Intubation Unit in morbid obese patients.

BACKGROUND: Tracheal intubation may be more difficult in morbidly obese (MO) patients than in the non-obese. The aim of this study was to evaluate clinically if the use of the Video Intubation Unit (VIU), a video-optical intubation stylet, could improve the laryngoscopic view compared with the standard Macintosh laryngoscope in this specific population. METHODS: We studied 40 MO patients (body mass index >35 kg/m(2)) scheduled for bariatric surgery. Each patient had a conventional laryngoscopy and a VIU inspection. The laryngoscopic grades (LG) using the Cormack and Lehane scoring system were noted and compared. Thereafter, the patients were randomised to be intubated with one of the two techniques. In one group, the patients were intubated with the help of the VIU and in the control group, tracheal intubation was performed conventionally. The duration of intubation, as well as the minimal SpO(2) achieved during the procedure, were measured. RESULTS: Patient characteristics were similar in both groups. Seventeen patients had a direct LG of 2 or 3 (no patient had a grade of 4). Out of these 17 patients, the LG systematically improved with the VIU and always attained grade 1 (P<0.0001). The intubation time was shorter within the VIU group, but did not attain significance. There was no difference in the SpO(2) post-intubation. CONCLUSION: In MO patients, the use of the VIU significantly improves the visualisation of the larynx, thereby improving the intubation conditions.

Thin Bonded Overlay Evaluation, Construction Report, HR-559, 1999

In recent years, ultra-thin whitetopping (UTW) has evolved as a viable rehabilitation technique for deteriorated asphalt cement concrete (ACC) pavement. Numerous UTW projects have been constructed and tested, enabling researchers to identify key elements contributing to their successful performance. These elements include foundation support, the interface bonding condition, portland cement concrete (PCC) overlay thickness, synthetic fiber reinforcement usage, joint spacing, and joint sealing. The interface bonding condition is the most important of these elements. It enables the pavement to act as a composite structure, thus reducing tensile stresses and allowing an ultra-thin PCC overlay to perform as intended. Although the main factors affecting UTW performance have been identified in previous research, neither the impact that external variables have on the elements nor the element interaction have been thoroughly investigated. The objective of this research was to investigate the interface bonding condition between an ultra-thin PCC overlay and an ACC base over time, considering the previously mentioned variables. Laboratory testing and full scale field testing were planned to accomplish the research objective. Laboratory testing involved monitoring interface strains in fabricated PCC/ACC composite test beams subjected to either static or dynamic flexural loading. Variables investigated included ACC surface preparation, PCC thickness, and synthetic fiber reinforcement usage. Field testing involved monitoring PCC/ACC interface stains and temperatures, falling weight deflectometer (FWD) deflection responses, direct shear strengths, and distresses on a 7.2 mile Iowa Department of Transportation (Iowa DOT) UTW project (HR-559). The project was located on Iowa Highway 21 between Iowa Highway 212 and U.S. Highway 6 in Iowa County, near Belle Plaine, Iowa. Variables investigated included ACC surface preparation, PCC thickness, synthetic fiber reinforcement usage, joint spacing, and joint sealing. This report documents the planning, equipment selection, and construction of the project built in 1994.

Evaluation of the Chemical Durability of Iowa Fly Ash Concretes, HR-327, 1993

The major objective of this research project was to investigate how Iowa fly ashes influenced the chemical durability of portland cement based materials. Chemical durability has become an area of uncertainty because of the winter application of deicer salts (rock salts) that contain a significant amount of sulfate impurities. The sulfate durability testing program consisted of monitoring portland cement-fly ash paste, mortar and concrete test specimens that had been subjected to aqueous solutions containing various concentrations of salts (both sulfate and chloride). The paste and mortar specimens were monitored for length as a function of time. The concrete test specimens were monitored for length, relative dynamic modulus and mass as a function of time. The alkali-aggregate reactivity testing program consisted of monitoring the expansion of ASTM C311 mortar bar specimens that contained three different aggregates (Pyrex glass, Oreapolis and standard Ottawa sand). The results of the sulfate durability study indicated that the paste and concrete test specimens tended to exhibit surface spalling but only very slow expansive tendencies. This suggested that the permeability of the test specimens was controlling the rate of deterioration. Concrete specimens are still being monitored because the majority of the test specimens have expanded less than 0.05%; hence, this makes it difficult to estimate the service life of the concrete test specimens or to quantify the performance of the different fly ashes that were used in the study. The results of the mortar bar studies indicated that the chemical composition of the various fly ashes did have an influence on their sulfate resistance. Typically, Clinton and Louisa fly ashes performed the best, followed by the Ottumwa, Neal 4 and then Council Bluffs fly ashes. Council Bluffs fly ash was the only fly ash that consistently reduced the sulfate resistance of the many different mortar specimens that were investigated during this study. None of the trends that were observed in the mortar bar studies have yet become evident in the concrete phase of this project. The results of the alkali-aggregate study indicated that the Oreapolis aggregate is not very sensitive to alkali attack. Two of the fly ashes, Council Bluffs and Ottumwa, tended to increase the expansion of mortar bar specimens that contained the Oreapolis aggregate. However, it was not clear if the additional expansion was due to the alkali content of the fly ash, the periclase content of the fly ash or the cristobalite content of the fly ash, since all three of these factors have been found to influence the test results.