136 research outputs found
New Anti-Corrosive Coatings with Resin-Bonded Polyaniline and Related Electroactive Groups
It is already known that polyaniline (an electroactive polymer) functions as a corrosion inhibitor for steel and in view of the fact that it is known to perform in the presence of hydrochloric acid, it has been considered likely that it may be useful to NASA for protecting launch structures at KSC which are exposed to not only continual ocean-side salt spray but also to hydrochloric acid at the times that solid-fuel boosters are fired. The currently used zinc-rich silicate-bonded coating is not wholly protective against the hydrochloric acid. Water pollution from zinc salts is another concern. Other earlier and concurrent NASA sponsored projects have been focussed on polyaniline specifically. Our project, administered for NASA by Dr. K. Thompson of KSC and these more-specifically polyaniline-related projects are included in a CRADA coordinated by Dr. F. Via of Akzo Nobel. A parallel project at Polytechnic under Prof K. Levon concentrated more specifically on polyaniline with various dopants. Our exploratory project reported herein was aimed at broadening the range of such corrosion inhibitors, to give protective paint compounders a wider latitude for adding corrosion inhibitors having polyaniline-like performance, and thus we diverged in several probing directions from polyaniline. Our working hypothesis was that physical variants of polyaniline, such as supported formulations on pigments or carriers, and chemical variants of polyaniline, including those having no electroconductive character, may have enhanced anticorrosion activity. We also hypothesized that small (non-polymeric) molecules having structures related to those occurring in polyaniline, may be active as corrosion inhibitors. We did preliminary testing, using an ASTM salt spray method at a nearby commercial paint testing laboratory. Our most interesting findings were that a non-electroconductive meta-isomer of polyaniline showed some corrosion activity, suggesting that the features of the polyaniline molecule associated with conductivity are not necessary for the anticorrosion action. Also, signtficantly, small molecular weight aromatic diamines and diimines resembling the reduced and the oxidized repeating unit in polyaniline showed an interesting degree of anticorrosive activity, suggesting that the polymeric feature of polyaniline is not necessary for anticorrosion action
Bone Marrow Transplantation for Feline Mucopolysaccharidosis I
Severe mucopolysaccharidosis type I (MPS I) is a fatal neuropathic lysosomal storage disorder with significant skeletal involvement. Treatment involves bone marrow transplantation (BMT), and although effective, is suboptimal, due to treatment sequelae and residual disease. Improved approaches will need to be tested in animal models and compared to BMT. Herein we report on bone marrow transplantation to treat feline mucopolysaccharidosis I (MPS I). Five MPS I stably engrafted kittens, transplanted with unfractionated bone marrow (6.3 Ă 107â1.1 Ă 109 nucleated bone marrow cells per kilogram) were monitored for 13â37 months post-engraftment. The tissue total glycosaminoglycan (GAG) content was reduced to normal levels in liver, spleen, kidney, heart muscle, lung, and thyroid. Aorta GAG content was between normal and affected levels. Treated cats had a significant decrease in the brain GAG levels relative to untreated MPS I cats and a paradoxical decrease relative to normal cats. The α-l-iduronidase (IDUA) activity in the livers and spleens of transplanted MPS I cats approached heterozygote levels. In kidney cortex, aorta, heart muscle, and cerebrum, there were decreases in GAG without significant increases in detectable IDUA activity. Treated animals had improved mobility and decreased radiographic signs of disease. However, significant pathology remained, especially in the cervical spine. Corneal clouding appeared improved in some animals. Immunohistochemical and biochemical analysis documented decreased central nervous system ganglioside storage. This large animal MPS I study will serve as a benchmark of future therapies designed to improve on BMT
Short-term effects of marijuana smoking on cognitive behavior in experienced male users
The effects of smoking marijuana on the ability to use abstract concepts was tested in 12 experienced marijuana users. Each subject was tested three times, after smoking prepared 300 mg cigarettes containing either 0, 1.5 or 2.9% ÎŽ 9 -THC in different sessions according to a Latin Square design. The same number of whole and/or partial cigarettes was smoked by each subject in each of the three sessions. This was determined for individual subjects by the number of 2.9% ÎŽ 9 -THC marijuana cigarettes that the subject had been willing to smoke in a pre-experimental session up to a maximum of 1200 mg. The following tests of concept formation and usage were used: 1. a letter series test; 2. a word grouping test; 3. a conceptual clustering memory test; 4. a closure speed test; 5. Witkin's Embedded Figures Test; 6. a size weight illusion test; 7. Luchin's Water Jar Test; 8. Luchin's Hidden Word Test; and 9. an anagram test. Marijuana smoking led to a dose-related impairment on the letter series, word grouping, closure speed, and Embedded Figures test. Performance on the size-weight illusion, Luchin's Water Jar, Luchin's Hidden Word, and the anagram tests were unaffected. Conceptual clustering decreased after marijuana smoking. In most cases only the differences between 0 and 2.9% ÎŽ 9 -THC marijuana were statistically significant.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46387/1/213_2004_Article_BF00429295.pd
Outcomes of Bilateral Cataract Surgery in Infants 7 to 24 Months of Age Using the Toddler Aphakia and Pseudophakia Treatment Study Registry
Purpose
To evaluate outcomes of bilateral cataract surgery in children aged 7 to 24 months and compare rates of adverse events (AEs) with other Toddler Aphakia and Pseudophakia Study (TAPS) registry outcomes.
Design
Retrospective clinical study at 10 Infant Aphakia Treatment Study (IATS) sites. Statistical analyses comparing this cohort with previously reported TAPS registry cohorts.
Participants
Children enrolled in the TAPS registry between 2004 and 2010.
Methods
Children underwent bilateral cataract surgery with or without intraocular lens (IOL) placement at age 7 to 24 months with 5 years of postsurgical follow-up.
Main Outcome Measures
Visual acuity (VA), occurrence of strabismus, AEs, and reoperations.
Results
A total of 40 children (76 eyes) who underwent bilateral cataract surgery with primary posterior capsulectomy were identified with a median age at cataract surgery of 11 months (7â23); 68% received a primary IOL. Recurrent visual axis opacification (VAO) occurred in 7.5% and was associated only with the use of an IOL (odds ratio, 6.10; P = 0.005). Glaucoma suspect (GS) was diagnosed in 2.5%, but no child developed glaucoma. In this bilateral cohort, AEs (8/40, 20%), including glaucoma or GS and VAO, and reoperations occurred in a similar proportion to that of the published unilateral TAPS cohort. When analyzed with children aged 1 to 7 months at bilateral surgery, the incidence of AEs and glaucoma or GS correlated strongly with age at surgery (P = 0.011/0.004) and glaucoma correlated with microcornea (P = 0.040) but not with IOL insertion (P = 0.15).
Conclusions
Follow-up to age 5 years after bilateral cataract surgery in children aged 7 to 24 months reveals a low rate of VAO and very rare glaucoma or GS diagnosis compared with infants with cataracts operated at < 7 months of age despite primary IOL implantation in most children in the group aged 7 to 24 months. The use of an IOL increases the risk of VAO irrespective of age at surgery
Outcomes of Bilateral Cataracts Removed in Infants 1 to 7 Months of Age Using the Toddler Aphakia and Pseudophakia Treatment Study Registry
Purpose
To evaluate outcomes of bilateral cataract surgery in infants 1 to 7 months of age performed by Infant Aphakia Treatment Study (IATS) investigators during IATS recruitment and to compare them with IATS unilateral outcomes.
Design
Retrospective case series review at 10 IATS sites.
Participants
The Toddler Aphakia and Pseudophakia Study (TAPS) is a registry of children treated by surgeons who participated in the IATS.
Methods
Children underwent bilateral cataract surgery with or without intraocular lens (IOL) placement during IATS enrollment years 2004 through 2010.
Main Outcome Measures
Visual acuity (VA), strabismus, adverse events (AEs), and reoperations.
Results
One hundred seventy-eight eyes (96 children) were identified with a median age of 2.5 months (range, 1â7 months) at the time of cataract surgery. Forty-two eyes (24%) received primary IOL implantation. Median VA of the better-seeing eye at final study visit closest to 5 years of age with optotype VA testing was 0.35 logarithm of the minimum angle of resolution (logMAR; optotype equivalent, 20/45; range, 0.00â1.18 logMAR) in both aphakic and pseudophakic children. Corrected VA was excellent (<20/40) in 29% of better-seeing eyes, 15% of worse-seeing eyes. One percent showed poor acuity (â„20/200) in the better-seeing eye, 12% in the worse-seeing eye. Younger age at surgery and smaller (<9.5 mm) corneal diameter at surgery conferred an increased risk for glaucoma or glaucoma suspect designation (younger age: odds ratio [OR], 1.44; P = 0.037; and smaller cornea: OR, 3.95; P = 0.045). Adverse events also were associated with these 2 variables on multivariate analysis (younger age: OR, 1.36; P = 0.023; and smaller cornea: OR, 4.78; P = 0.057). Visual axis opacification was more common in pseudophakic (32%) than aphakic (8%) eyes (P = 0.009). Unplanned intraocular reoperation occurred in 28% of first enrolled eyes (including glaucoma surgery in 10%).
Conclusions
Visual acuity after bilateral cataract surgery in infants younger than 7 months is good, despite frequent systemic and ocular comorbidities. Although aphakia management did not affect VA outcome or AE incidence, IOL placement increased the risk of visual axis opacification. Adverse events and glaucoma correlated with a younger age at surgery and glaucoma correlated with the presence of microcornea
A Prospective Study of Aspirin Use and the Risk of Gastrointestinal Bleeding in Men
Data regarding the influence of dose and duration of aspirin use on risk of gastrointestinal bleeding are conflicting.We conducted a prospective cohort study of 32,989 men enrolled in the Health Professionals Follow-up Study (HPFS) in 1994 who provided biennial aspirin data. We estimated relative risk of major gastrointestinal bleeding requiring hospitalization or a blood transfusion.During 14 years of follow-up, 707 men reported an episode of major gastrointestinal bleeding over 377,231 person-years. After adjusting for risk factors, regular aspirin use (â„2 times/week) had a multivariate relative risk (RR) of gastrointestinal bleeding of 1.32 (95% confidence interval [CI], 1.12-1.55) compared to non-regular use. The association was particularly evident for upper gastrointestinal bleeding (multivariate RR, 1.49; 95% CI, 1.16-1.92). Compared to men who denied any aspirin use, multivariate RRs of upper gastrointestinal bleeding were 1.05 (95% CI 0.71-1.52) for men who used 0.5-1.5 standard tablets/week, 1.31 (95% CI 0.88-1.95) for 2-5 aspirin/week, 1.63 (95% CI, 1.15-2.32) for 6-14 aspirin/week and 2.40 (95% CI, 1.10-5.22) for >14 aspirin/week (P(trend)<0.001). The relative risk also appeared to be dose-dependent among short-term users <5 years; P(trend)<.001) and long-term users (â„5 years; P(trend)â=â0.015). In contrast, after controlling for dose, increasing duration of use did not appear to be associated with risk (P(trend)â=â0.749).Regular aspirin use increases the risk of gastrointestinal bleeding, especially from the upper tract. However, risk of bleeding appears to be more strongly related to dose than to duration of use. Risk of bleeding should be minimized by using the lowest effective dose among short-term and long-term aspirin users
Genome modeling system: A knowledge management platform for genomics
In this work, we present the Genome Modeling System (GMS), an analysis information management system capable of executing automated genome analysis pipelines at a massive scale. The GMS framework provides detailed tracking of samples and data coupled with reliable and repeatable analysis pipelines. The GMS also serves as a platform for bioinformatics development, allowing a large team to collaborate on data analysis, or an individual researcher to leverage the work of others effectively within its data management system. Rather than separating ad-hoc analysis from rigorous, reproducible pipelines, the GMS promotes systematic integration between the two. As a demonstration of the GMS, we performed an integrated analysis of whole genome, exome and transcriptome sequencing data from a breast cancer cell line (HCC1395) and matched lymphoblastoid line (HCC1395BL). These data are available for users to test the software, complete tutorials and develop novel GMS pipeline configurations. The GMS is available at https://github.com/genome/gms
Private Sector Union Density and the Wage Premium: Past, Present, and Future
The rise and decline of private sector unionization were among the more important features of the U.S. labor market during the twentieth century. Following a dramatic spurt in unionization after passage of the depression-era National Labor Relations Act (NLRA) of 1935, union density peaked in the mid-1950s, and then began a continuous decline. At the end of the century, the percentage of private wage and salary workers who were union members was less than 10 percent, not greatly different from union density prior to the NLRA
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