427 research outputs found
Shear-induced quench of long-range correlations in a liquid mixture
A static correlation function of concentration fluctuations in a (dilute)
binary liquid mixture subjected to both a concentration gradient and uniform
shear flow is investigated within the framework of fluctuating hydrodynamics.
It is shown that a well-known long-range correlation at
large wave numbers crosses over to a weaker divergent one for wave numbers
satisfying , while an asymptotic shear-controlled
power-law dependence is confirmed at much smaller wave numbers given by , where , , and are the
mass concentration, the rate of the shear, the mass diffusivity and the
kinematic viscosity of the mixture, respectively. The result will provide for
the first time the possibility to observe the shear-induced suppression of a
long-range correlation experimentally by using, for example, a low-angle light
scattering technique.Comment: 8pages, 2figure
Factors associated with risky sun exposure behaviors among operating engineers
Background The objective of this study was to determine the factors associated with sun exposure behaviors among Operating Engineers (heavy equipment operators). Methods Operating Engineers (N = 498) were asked to complete a cross‐sectional survey. Linear and logistic regression analyses were used to determine health behavioral, perceptional, and demographic factors associated with sun exposure behavior (sun burns, blistering, use of sunscreen, and interest in sun protection services). Results Almost half reported two or more sunburns/summer and the median times blistering was 2 with a range of 0–100. About one‐third never used sun block, while just over one‐third rarely used sun block. Almost one‐quarter were interested in sun protection guidance. Multivariate analyses showed that perceptions of skin type, alcohol problems, fruit intake, BMI, sleep quality, age, sex, and race were significantly associated with at least one of the outcome variables ( P < 0.05). Conclusions Operating Engineers are at high risk for skin cancer due to high rates of exposure to ultraviolet light and low rates of sun block use. Subgroups of Operating Engineers are particularly at risk for sun damage. Interventions are needed to decrease sun exposure among Operating Engineers. Am. J. Ind. Med. 55:786–792, 2012. © 2012 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93541/1/22079_ftp.pd
A Molecular Hydrodynamic Theory of Supercooled Liquids and Colloidal Suspensions under Shear
We extend the conventional mode-coupling theory of supercooled liquids to
systems under stationary shear flow. Starting from generalized fluctuating
hydrodynamics, a nonlinear equation for the intermediate scattering function is
constructed. We evaluate the solution numerically for a model of a two
dimensional colloidal suspension and find that the structural relaxation time
decreases as with an exponent , where
is the shear rate. The results are in qualitative agreement with
recent molecular dynamics simulations. We discuss the physical implications of
the results.Comment: 5 pages, 1 figur
Phototherapeutic keratectomy for the treatment of dense subepithelial infiltrates after epidemic keratoconjunctivitis
This is a case report of a patient who developed dense subepithelial corneal infiltrates after epidemic keratoconjunctivitis and was treated with phototherapeutic keratectomy (PTK). The purpose of this case report is to explain the surgical technique and the results of PTK procedure
Evaluating the safety and efficacy of photorefractive keratectomy combined with corneal collagen crosslinking for the treatment of myopia and myopic astigmatism
INTRODUCTION. The purpose of the study was to evaluate the safety and efficacy of photorefractive keratectomy (PRK) combined with corneal collagen crosslinking (CXL) in patients with potential risk of developing postoperative ectasia, who were not good candidates for LASIK.
MATERIALS AND METHODS. Twenty eyes were treated with transepithelial PRK combined with CXL. Patients were evaluated preoperatively for best corrected visual acuity (BCVA), refraction, keratometry, topography, and endothelial cell count. All eyes were treated with Amaris 750s Excimer Laser and KXL system for 90 seconds at 30 mW/cm2.
RESULTS. Mean BCVA was improved from 0.0075 ± 0.08 logMAR to 0.025 ± 0.05 logMAR postoperatively. Average keratometry reduced from 44.9 ± 1.9 D to 39.8 ± 3.9 D. Mean minimal corneal thickness reduced from 504 ± 16.7 μm to 405 ± 41 μm. None of the cases developed regression, corneal ectasia, or corneal haze.
CONCLUSIONS. Photorefractive keratectomy combined with high-fluence corneal collagen crosslinking (PRK XTRA) appears to be a safe and effective treatment for patients who are not good candidates for LASIK
KAMRA corneal inlay for the correction of presbyopia
This is a case report of two patients who underwent presbyopia correction with KAMRA corneal inlay (KAMRA; AcuFocus, Irvine, CA) combined with LASIK surgery. The surgical technique is thoroughly explained, as well as the advantages and disadvantages of the procedure. In both patients, near uncorrected visual acuity significantly improved and distance uncorrected visual acuity remained unchanged. There were no changes in the corneal topography after the corneal inlay implantation
Partial transepithelial topography-guided PRK combined with corneal collagen crosslinking in patients with keratoconus
INTRODUCTION. The aim of this study is to identify the visual outcome and possible complications of partial transepithelial topography-guided PRK combined with collagen crosslinking in patients with keratoconus.
MATERIALS AND METHODS. Twenty eyes (20 patients) were treated with partial transepithelial topography-guided PRK combined with collagen crosslinking. Patients were evaluated preoperatively for best spectacle corrected visual acuity (BSCVA), clinical signs of keratoconus via slit lamp examination, and Scheimpflug-generated corneal topography. All eyes were treated with Amaris 750s Excimer Laser and KXL system.
RESULTS . Mean BCVA was improved from 20/100 to 20/25, postoperatively. Mean flat K was 46.8 ± 0.14 D preoperatively and was reduced to 45.2 ± 0.7 D postoperatively. Mean steep K was reduced from 50.2 ± 0.10 D to 47 ± 0.6 D. Total corneal astigmatism was 4.5 ± 0.14 D and decreased to 2.5 ± 0.10 D postoperatively. Average thinnest pachymetry was reduced from 465 ± 9.9 μm to 416 ± 11.3 μm. Total RMS (corneal aberrations) was 15.5 ± 7.4μm and was significantly reduced to 5.5 ± 2 μm.
CONCLUSIONS. Partial transepithelial topography-guided PRK combined with collagen crosslinking can benefit patients fitting the criteria for such a procedure, by stabilising their cornea as well as improving their BSCVA.
Protocol of a randomized controlled trial of sun protection interventions for operating engineers
Abstract
Background
Skin cancer are increasing and some types of skin cancer are among the most lethal cancers yet are easily preventable. However, sun protection interventions are rarely implemented among outdoor workers. Our prior work shows that Michigan Operating Engineers (heavy equipment operators) spend an average of 4–5 hours in the sun, about one-third reported getting sun burned at least once a summer, and over half burned more than once a summer. About three-quarters of the sample never or only sometimes used sun block.
Methods/design
Using the Health Belief Model as a guide, this randomized controlled trial (RCT) will test the efficacy of four sun protection interventions targeting Operating Engineers: a) education only; b) education and mailed sunscreen; c) education and text message reminders; and, d) education, mailed sunscreen, and text message reminders. Participations in the study will be offered during regularly scheduled safety trainings at the Local 324 Training Center. Pre- and post-intervention surveys will be collected to determine changes in sunscreen use and sun burning, the primary dependent variables. The analyses will include: a) paired t-tests to determine changes over time (from pre-intervention to post–intervention) in outcome variables (sunscreen use and burning) separately in the 4 intervention groups, b) Repeated Measures Analysis of Variance (RM-ANOVA) to compare the changes in outcomes across the 4 groups, and c) t-tests on change scores as follow-ups to the RM-ANOVA to determine exactly which groups differ from each other.
Discussion
Based on the outcome of this study, we will develop a RO1 for wider scale testing and dissemination in conjunction with the International Training Center which services North America (including the US, Mexico, and Canada). Wide scale dissemination of an efficacious sun protection intervention has the potential to substantially impact skin cancer rates among this population. The ultimate goal is for high reach, high efficacy, and low cost.
Trial registration
NCT01804595http://deepblue.lib.umich.edu/bitstream/2027.42/112879/1/12889_2013_Article_5170.pd
Role of Nutrition in Alcoholic Liver Disease: Summary of the Symposium at the ESBRA 2017 Congress.
The symposium, "Role of Nutrition in Alcoholic Liver Disease", was held at the European Society for Biomedical Research on Alcoholism Congress on 9 October 2017 in Crete, Greece. The goal of the symposium was to highlight recent advances and developments in the field of alcohol and nutrition. The symposium was focused on experimental and clinical aspects in relation to the role of different types of dietary nutrients and malnutrition in the pathogenesis of alcoholic liver disease (ALD). The following is a summary of key research presented at this session. The speakers discussed the role of dietary fats and carbohydrates in the development and progression of alcohol-induced multi-organ pathology in animal models of ALD, analyzed novel nutrition-related therapeutics (specifically, betaine and zinc) in the treatment of ALD, and addressed clinical relevance of malnutrition and nutrition support in ALD. This summary of the symposium will benefit junior and senior faculty currently investigating alcohol-induced organ pathology as well as undergraduate, graduate, and post-graduate students and fellows
Evaluation and costs of volunteer telephone cessation follow-up counseling for Veteran smokers discharged from inpatient units: a quasi-experimental, mixed methods study
Abstract
Background
The Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework was used to evaluate the volunteer telephone smoking cessation counseling follow-up program implemented as part of the inpatient Tobacco Tactics intervention in a Veterans Affairs (VA) hospital.
Methods
This was a quasi-experimental, mixed methods design that collected data through electronic medical records (EMR), observations of telephone smoking cessation counseling calls, interviews with staff and Veterans involved in the program, and intervention costs.
Results
Reach: Of the 131 Veterans referred to the smoking cessation telephone follow-up program, 19% were reached 0–1 times, while 81% were reached 2–4 times. Effectiveness: Seven-day point-prevalence 60-day quit rates (abstracted from the EMR) for those who were reached 2–4 times were 26%, compared to 8% among those who were reached 0–1 times (p = 0.06). Sixty-day 24-hour point-prevalence quit rates were 33% for those reached 2–4 times, compared to 4% of those reached 0–1 times (p < 0.01). Adoption and Implementation: The volunteers correctly followed protocol and were enthusiastic about performing the calls. Veterans who were interviewed reported positive comments about the calls. The cost to the hospital was 92. Maintenance: There was short-term maintenance (about 1 year), but the program was not sustainable long term.
Conclusions
Quit rates were higher among those Veterans that had greater participation in the calls. Joint Commission standards for inpatient smoking with follow-up calls are voluntary, but should these standards become mandatory, there may be more motivation for VA administration to institute a hospital-based, volunteer telephone smoking cessation follow-up program.
Trial registration
ClinicalTrials.Gov
NCT01359371
.http://deepblue.lib.umich.edu/bitstream/2027.42/110514/1/12971_2015_Article_28.pd
- …