Work-related injuries and illnesses and their association with hour of work: Analysis of the Oregon construction industry in the US using workers' compensation accepted disabling claims, 2007-2013.

OBJECTIVES: This study aimed to characterize injuries and illnesses among construction workers in the State of Oregon in the US and examine the association between injury frequency and severity with hour of work by using Workers' Compensation (WC) accepted disabling claims data in the construction industry from 2007 to 2013. METHODS: Injury frequency, rate, medical cost, and lost work days were analyzed by year, demographics, employment, injury nature, and temporal factors including hour of work. Multiple linear regression models were used to quantify adjusted associations between hour of work and medical cost and lost work days (indicating injury severity). RESULTS: There were a total of 12 222 disabling claims in the Oregon construction industry. The average annual injury rate was 2.21 per 100 workers. Both the count and rate of disabling claims decreased during the study period. Male workers and young workers had higher injury rates, while medical cost and lost work days increased for older workers. Injuries occurring at night were more severe. The distribution of claims frequency by hour of work was bimodal, with peaks in the 4th and 8th hour. Compared with the first hour of work, the 5th and 13th hours corresponded to significantly more severe injuries and illnesses. CONCLUSIONS: This study identified the burden and distribution of work-related injuries and illnesses in the Oregon construction industry. Continued intervention efforts should target certain subpopulations (eg, young workers) and certain working time periods (eg, mid- and end-shift) to protect construction workers' safety and health.

The distribution of implant fixation for femoral components of TKA: a postmortem retrieval study.

Aseptic loosening of total knee arthroplasty (TKA) components is the foremost cause of implant failure in the long term. While tibial component loosening is of primary concern, femoral loosening may become a clinical problem due to younger, more active patients seeking TKA, and also high-flexion designs. In this study, we analyzed the fixation for 19 non-revised, postmortem retrieved, femoral components of TKA with time in service ranging from 1 to 22 years. We found that the average total contact fraction for cemented components was 9.5% and had a power law response (decrease) with years in service. The average initial interdigitation depth was 0.7mm, and the average current interdigitation depth was 0.13mm. Loss of interdigitation was 81%. Over all, minimal fixation seems necessary for long-term success of TKA femoral components.

A novel in vitro loading system to produce supraphysiologic oscillatory fluid shear stress.

A multi-well fluid loading (MFL) system was developed to deliver oscillatory subphysiologic to supraphysiologic fluid shear stresses to cell monolayers in vitro using standard multi-well culture plates. Computational fluid dynamics modeling with fluid-structure interactions was used to quantify the squeeze film fluid flow between an axially displaced piston and the well plate surface. Adjusting the cone angle of the piston base modulated the fluid pressure, velocity, and shear stress magnitudes. Modeling results showed that there was near uniform fluid shear stress across the well with a linear drop in pressure across the radius of the well. Using the MFL system, RAW 264.7 osteoclastic cells were exposed to oscillatory fluid shear stresses of 0, 0.5, 1.5, 4, 6, and 17 Pa. Cells were loaded 1 h per day at 1 Hz for two days. Compared to sub-physiologic and physiologic levels, supraphysiologic oscillatory fluid shear induced upregulation of osteoclastic activity as measured by tartrate-resistant acid phosphatase activity and formation of mineral resorption pits. Cell number remained constant across all treatment groups.

An evaluation of the PALS after treatment modelling intervention to reduce dental anxiety in child dental patients.

AIM: The aim of this study was to assess the effectiveness of the passivity to activity through live symbolic (PALS) after treatment modelling intervention to reduce child dental anxiety. METHODS: A convenience sample of consecutive 5- to 10-year-old dental patients were randomly assigned to intervention or control groups. Self-reported child dental anxiety was assessed at the start of each visit. At the end of each visit, children in the intervention group were introduced to a glove puppet, which acted as the PALS model. The intervention group children re-enacted the treatment they had just received on the puppet's teeth. At the end of each visit, the control children received motivational rewards only. The change in dental anxiety scores was examined by t-tests and analysis of covariance. RESULTS: The final analysis included 27 intervention children and 26 control children. For the intervention group, there were no statistically significant changes in dental anxiety over a course of treatment, between first and second preventive visits, between first and second invasive treatment visits, or between first attendance and subsequent recall attendance. For the control group, a statistically significant decrease in dental anxiety was observed between the first and second invasive dental treatment visits. CONCLUSION: The PALS after treatment modelling intervention was ineffective in reducing child dental anxiety.

Reliability and validity of a faces version of the Modified Child Dental Anxiety Scale.

BACKGROUND: A new version of the Modified Child Dental Anxiety Scale (MCDAS) was formed by adding a faces rating scale to the original numeric form. AIMS: To describe the psychometric properties of the faces version of the Modified Child Dental Anxiety Scale (MCDAS(f)), and to provide normative data for dental anxiety for children using the MCDAS(f). DESIGN: To determine the test-retest reliability, 287 schoolchildren aged 8-10 years completed the MCDAS(f) on two separate occasions 17 weeks apart. To determine the criterion validity, 207 schoolchildren aged 10-12 years completed the MCDAS(f) and the CFSS-DS at the same sitting. Construct validity was assessed using a cohort of 206 consecutive child dental patients and their parents. RESULTS: The MCDAS(f) showed good test-retest reliability (intraclass correlation coefficient = 0.80) and internal consistency (Cronbach's alpha = 0.82). The MCDAS(f) significantly correlated with the CFSS-DS (r = 0.80, P < 0.001). Dental anxiety assessed using the MCDAS(f) was related to the dmft (t = -2.17, P = 0.03), DMFT (t = -4.19, P < 0.001), and dental general anaesthetic experience (t = -4.46, P < 0.01). The mean MCDAS(f) score for the normative sample (n = 475) was 19.81 (95% CI: 19.20, 20.43). CONCLUSIONS: The MCDAS(f) is a reliable and valid measure of dental anxiety in children aged 8-12 years.

Quantitative analysis of cyanobacterial toxins by matrix-assisted laser desorption ionization mass spectrometry.

Microcystins (MCs) are a growing problem in drinking water supplies worldwide. Common analytical techniques used to determine MC concentrations have several shortcomings, including extensive sample handling and lengthy analysis times. A simple, rapid method for quantitation of MCs by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is presented. Four potential internal standards were tested, including an 15N-labeled MC. For MC-LR in mixed standard solutions, a linear range of 0.11-5.0 microM (R2 = 0.98) was achieved, with a method detection limit (MDL) of 0.015 microM. Matrix effects due to extracted cell components decreased the MC-LR linear range slightly to 0.19-5.0 microM (R2 = 0.99), with MDL = 0.058 microM. Extensive analysis of possible internal standards indicates that nodularin was preferred over [15N]10-microcystin-YR or angiotensin I. The ionization efficiency and analyte-analyte suppression for four MCs of varying polarity are presented; the three polar congeners exhibited good ionization efficiency and acceptable levels of analyte-analyte suppression. These results indicate that MALDI-TOF MS represents a viable alternative for the quantitative measurement of MCs in field samples.

Adduct simplification in the analysis of cyanobacterial toxins by matrix-assisted laser desorption/ionization mass spectrometry.

A novel method for simplifying adduct patterns to improve the detection and identification of peptide toxins using matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry is presented. Addition of 200 microM zinc sulfate heptahydrate (ZnSO(4) . 7H(2)O) to samples prior to spotting on the target enhances detection of the protonated molecule while suppressing competing adducts. This produces a highly simplified spectrum with the potential to enhance quantitative analysis, particularly for complex samples. The resulting improvement in total signal strength and reduction in the coefficient of variation (from 31.1% to 5.2% for microcystin-LR) further enhance the potential for sensitive and accurate quantitation. Other potential additives tested, including 18-crown-6 ether, alkali metal salts (lithium chloride, sodium chloride, potassium chloride), and other transition metal salts (silver chloride, silver nitrate, copper(II) nitrate, copper(II) sulfate, zinc acetate), were unable to achieve comparable results. Application of this technique to the analysis of several microcystins, potent peptide hepatotoxins from cyanobacteria, is illustrated.

Depressive symptoms in and type of classroom placement for adolescents with LD.

This study investigated the relationship of depressive symptomatology to type of classroom placement in a sample of adolescents with learning disabilities who attended an urban public high school. Fifty-two students, half of whom were in self-contained classrooms and half of whom were in general education classrooms with resource room, self-rated their depressive symptoms. Their guidance counselors also rated these students' depressive symptoms. Self-ratings of depression did not differ depending on classroom placement. Guidance counselors rated students with learning disabilities who were in general education classrooms as more depressed than students placed in self-contained classes.