SEARCH · Search PubMed
Results for “Hobbies”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Survival of patients with congestive heart failure.
Explore the source record for details and available documents.
Letter: Confusion of calories prevented by joules.
Explore the source record for details and available documents.
Cuber's thumb.
Explore the source record for details and available documents.
Chronic health conditions in adult survivors of childhood cancer.
BACKGROUND: Only a few small studies have assessed the long-term morbidity that follows the treatment of childhood cancer. We determined the incidence and severity of chronic health conditions in adult survivors. METHODS: The Childhood Cancer Survivor Study is a retrospective cohort study that tracks the health status of adults who received a diagnosis of childhood cancer between 1970 and 1986 and compares the results with those of siblings. We calculated the frequencies of chronic conditions in 10,397 survivors and 3034 siblings. A severity score (grades 1 through 4, ranging from mild to life-threatening or disabling) was assigned to each condition. Cox proportional-hazards models were used to estimate hazard ratios, reported as relative risks and 95% confidence intervals (CIs), for a chronic condition. RESULTS: Survivors and siblings had mean ages of 26.6 years (range, 18.0 to 48.0) and 29.2 years (range, 18.0 to 56.0), respectively, at the time of the study. Among 10,397 survivors, 62.3% had at least one chronic condition; 27.5% had a severe or life-threatening condition (grade 3 or 4). The adjusted relative risk of a chronic condition in a survivor, as compared with siblings, was 3.3 (95% CI, 3.0 to 3.5); for a severe or life-threatening condition, the risk was 8.2 (95% CI, 6.9 to 9.7). Among survivors, the cumulative incidence of a chronic health condition reached 73.4% (95% CI, 69.0 to 77.9) 30 years after the cancer diagnosis, with a cumulative incidence of 42.4% (95% CI, 33.7 to 51.2) for severe, disabling, or life-threatening conditions or death due to a chronic condition. CONCLUSIONS: Survivors of childhood cancer have a high rate of illness owing to chronic health conditions.
Optical anisotropy of nanotube suspensions.
A semimacroscopic model of an optically anisotropic nanotube suspension is derived perturbatively from Maxwell's equations in a dielectric medium. We calculate leading-order expressions, valid in the dilute and semidilute limits, for the intrinsic and form contributions to the complex dielectric tensor in terms of the volume fraction, mean orientation, aspect ratio, optical anisotropy, and optical contrast of the nanotubes. The birefringence and dichroism are derived explicitly to leading order in fluctuations, and the connection with depolarized light scattering is established. The results are generalized to include tube deformation.
Rheo-optical studies of carbon nanotube suspensions.
We use a polarization-modulation technique to investigate the optical anisotropy of multi- and single-wall carbon nanotubes suspended in a variety of solvents under simple shear flow. Measurements of birefringence and dichroism are performed as a function of shear rate, tube concentration, and solvent viscosity. At fixed volume fraction, the anisotropy increases with increasing shear stress due to enhanced flow alignment. At fixed shear stress, the anisotropy increases with volume fraction due to rotational excluded-volume interactions. By considering the rotational diffusivity as a function of nanotube length, diameter, concentration, and solvent viscosity, we demonstrate a leading-order scaling relation for the optical anisotropy in terms of rotary Peclet number Pe. At low Pe, our results are in qualitative agreement with the theoretical predictions of Doi and Edwards. At high Pe, our data suggest that the degree of nanotube alignment scales as Pe16.
Charge transport in melt-dispersed carbon nanotubes.
We investigate the effect of interfacial stabilizer on charge transport in polymer-dispersed carbon nanotubes. Despite mechanical contact, samples with dispersant show poor conductivity, which we attribute to a robust interfacial layer between contacted nanotubes. In comparison, results obtained when nanotubes are mechanically mixed into polymer melts without dispersant show much better conductivity. The difference is striking; at comparable loading, neat melt composites have resistivities five orders of magnitude smaller than those containing interfacial stabilizer. Our results highlight a fundamental issue for the engineering of conducting carbon nanotube composites; dispersion stability will typically be achieved at the expense of conductivity.
Medical assessment of children going into emergency out-of-home placement.
Approximately 500,000 children and infants go into out-of-home placement in the United States each year. Increased attention is being given to the health care of children as they enter and remain in placement. This article describes a model, which has been in operation for 5 years, that provides medical assessments of children as they enter emergency out-of-home placement. The model is a community partnership with the county social service department, the police department, and the hospital. A computerized database that contains records for each child, including medical findings, has been helpful in developing a profile of the children served and contributes to continuity of care.
There is no second. Presidential address. Society for Vascular Surgery.
Explore the source record for details and available documents.
23S rRNA base pair 2057-2611 determines ketolide susceptibility and fitness cost of the macrolide resistance mutation 2058A-->G.
The 23S rRNA A2058G alteration mediates macrolide, lincosamide, and streptogramin B resistance in the bacterial domain and determines the selectivity of macrolide antibiotics for eubacterial ribosomes, as opposed to eukaryotic ribosomes. However, this mutation is associated with a disparate resistance phenotype: It confers high-level resistance to ketolides in mycobacteria but only marginally affects ketolide susceptibility in streptococci. We used site-directed mutagenesis of nucleotides within domain V of 23S rRNA to study the molecular basis for this disparity. We show that mutational alteration of the polymorphic 2057-2611 base pair from A-U to G-C in isogenic mutants of Mycobacterium smegmatis significantly affects susceptibility to ketolides but does not influence susceptibility to other macrolide antibiotics. In addition, we provide evidence that the 2057-2611 polymorphism determines the fitness cost of the 23S rRNA A2058G resistance mutation. Supported by structural analysis, our results indicate that polymorphic nucleotides mediate the disparate phenotype of genotypically identical resistance mutations and provide an explanation for the large species differences in the epidemiology of defined drug resistance mutations.
Testing neoclassical competitive market theory in the field.
This study presents results from a pilot field experiment that tests predictions of competitive market theory. A major advantage of this particular field experimental design is that my laboratory is the marketplace: subjects are engaged in buying, selling, and trading activities whether I run an exchange experiment or am a passive observer. In this sense, I am gathering data in a natural environment while still maintaining the necessary control to execute a clean comparison between treatments. The main results of the study fall into two categories. First, the competitive model predicts reasonably well in some market treatments: the expected price and quantity levels are approximated in many market rounds. Second, the data suggest that market composition is important: buyer and seller experience levels impact not only the distribution of rents but also the overall level of rents captured. An unexpected result in this regard is that average market efficiency is lowest in markets that match experienced buyers and experienced sellers and highest when experienced buyers engage in bargaining with inexperienced sellers. Together, these results suggest that both market experience and market composition play an important role in the equilibrium discovery process.
Oxidized Cotton, an Immunologically Specific Polysaccharide.
Explore the source record for details and available documents.
On the interpretation of experiments on osmotic pressure.
Scholander and his coworkers have described in These Proceedings several experiments in which the osmotic pressure exerted by colloidal particles appears to be altered when the particles are subject to an external force; they interpret the experiments as showing that the traditional explanation of osmotic pressure is wrong (Proc. Nat. Acad. Sci. USA 68, 1093-1094; 68, 1569-1571; 70, 124-128). (In their view the osmotic pressure is determined by the concentration of the colloidal particles at the free surface rather than at the semipermeable membrane.) This note shows that one must also consider the way in which the external force changes the total hydrostatic pressure in the liquid. When that is done, the experiments of Scholander et al. are quantitatively consistent with the traditional interpretation of osmotic pressure.
Correlation of synovial fluid cytokine levels with histological and clinical parameters of primary and revision total hip and total knee replacements.
We retrieved synovial tissue and fluid samples from patients undergoing primary total hip replacement (THR) (n 15), revision of aseptically loose THR (n 12), primary total knee replacement (TKR) (n 13) and revision of aseptically loose TKR (n 6). Several histological parameters were assessed on a relative scale of 14. Primary TJRs were clinically evaluated for degree of osteoarthrosis. Revision TJRs were assessed for migration of the implant, gross loosening and the degree of radiolucency. Cytokine levels in synovial fluid were determined with ELISA. All cytokines were significantly higher in revision TJRs than in primary replacements, as were the degree of macrophage and giant cell infiltration. We found no relationship between any clinical variable and the levels of any cytokine, but migration of the implant was related to the presence of PE debris. A significant correlation was seen between the presence of macrophages and the levels of IL-1beta, IL-8 and IL-10, but not IL-6. No differences were noted between hips and knees for any of the variables, except in the levels of IL-6, where higher levels were found in THRs. These results suggest a unique role for IL-6 that requires further investigation.
Amateur radio operators and exposure to polychlorinated biphenyls.
In September, 1982, the Special Studies Branch, Chronic Diseases Division, Center for Environmental Health, Centers for Disease Control, was alerted to the possibility that oils in certain oil-filled devices used by amateur radio operators throughout the country were contaminated with polychlorinated biphenyls (PCBs). To evaluate the possible exposures and concomitant health risks, we conducted an exposure assessment study in two phases: an evaluation of the prevalence of environmental contaminations and an assessment of human exposure. Of 77 oil samples collected, only 2 were contaminated above a 50-ppm level; analyses of blood specimens collected from these two owner-operators showed serum PCB-levels which were well within a "normal" or expected background range. Although, on the basis of these limited data, PCBs from contaminated oils do not appear to be a hazard to amateur radio operators, we recommend that PCB-contaminated oils should not be used because of the continuing potential for exposure from either inhalation or direct contamination.
The occupational history in medical practice. What questions to ask and when to ask them.
Explore the source record for details and available documents.