Improvement of Creep Strength and Low-temperature Ductility of Refractory Metals by Means of Mechanical Twinning Final Report

Mechanical twinning for improving creep strength and low temperature ductility of refractory metal

Impact of Compliance to Oral Hypoglycemic Agents on Short-Term Disability Costs in an Employer Population

This study evaluated the relationships between compliance with oral hypoglycemic agents and health care/short-term disability costs in a large manufacturing company. The retrospective analysis used an observational cohort drawn from active employees of Ford Motor Company. The study population consisted of 4978 individuals who were continuously eligible for 3 years (between 2001?2007) and who received a prescription for an oral hypoglycemic agent during that time. Medical, pharmacy, and short-term disability claims data were obtained from the University of Michigan Health Management Research Center data warehouse. Pharmacy claims/refill data were used to calculate the proportion of days covered (PDC); an individual was classified as compliant if his/her PDC was ≥80%. Model covariates included age, sex, work type, and Charlson comorbidity scores. The impact of compliance on disability and health care costs was measured by comparing the costs of the compliant with those of the noncompliant during a 1-year follow-up. Among these employees, compliant patients had lower medical, higher pharmacy, and lower short-term disability costs than did the noncompliant. After adjusting for demographics and comorbidity, noncompliance was associated with statistically higher short-term disability costs ($1840 vs.$1161, P<0.0001), longer short-term disability duration, and an increase in short-term disability incidence (21.5% of the noncompliant had a claim compared to 16.0% of the compliant, P<0.0001). These results suggest that medication compliance may be important in curtailing the rise of health care/disability costs in the workplace. Employers concerned with the total costs associated with diabetes should not overlook the impact of compliance on short-term disability. (Population Health Management 2014;17:35-41)Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140180/1/pop.2013.0009.pd

The influence of barefoot and barefoot inspired footwear on the kinetics and kinematics of running in comparison to conventional running shoes.

Barefoot running has experienced a resurgence in footwear biomechanics literature, based on the supposition that it serves to reduce the occurrence of overuse injuries in comparison to conventional shoe models. This consensus has lead footwear manufacturers to develop shoes which aim to mimic the mechanics of barefoot locomotion. This study compared the impact kinetics and 3-D joint angular kinematics observed whilst running: barefoot, in conventional cushioned running shoes and in shoes designed to integrate the perceived benefits of barefoot locomotion. The aim of the current investigation was therefore to determine whether differences in impact kinetics exist between the footwear conditions and whether shoes which aim to simulate barefoot movement patterns can closely mimic the 3-D kinematics of barefoot running. Twelve participants ran at 4.0 m.s-1±5% in each footwear condition. Angular joint kinematics from the hip, knee and ankle in the sagittal, coronal and transverse planes were measured using an eight camera motion analysis system. In addition simultaneous tibial acceleration and ground reaction forces were obtained. Impact parameters and joint kinematics were subsequently compared using repeated measures ANOVAs. The kinematic analysis indicates that in comparison to the conventional and barefoot inspired shoes that running barefoot was associated significantly greater plantar-flexion at footstrike and range of motion to peak dorsiflexion. Furthermore, the kinetic analysis revealed that compared to the conventional footwear impact parameters were significantly greater in the barefoot condition. Therefore this study suggests that barefoot running is associated with impact kinetics linked to an increased risk of overuse injury, when compared to conventional shod running. Furthermore, the mechanics of the shoes which aim to simulate barefoot movement patterns do not appear to closely mimic the kinematics of barefoot locomotion

Worker Productivity Loss Associated with Arthritis

This study at a major financial services corporation sought to investigate the association of arthritis with on-the-job productivity, also termed "presenteeism." Using a modified version of the Work Limitations Questionnaire (WLQ) incorporated into a Health Risk Appraisal (HRA), 17,685 employees responded to the survey in 2002. Of the 16,651 respondents meeting inclusion criteria, 2,469 (14.8%) reported having arthritis, and 986 (39.9% of those with arthritis) also reported that they were under medical care and/or taking medication for arthritis. Employees with arthritis were older, predominantly female, and reported a higher number of comorbidities. Although all four domains of the WLQ (physical, time, mental, and output) were impacted by arthritis, the greatest productivity effect, as expected, was on physical work tasks. Health risks also play a role in the relationship between arthritis and presenteeism, with high-risk individuals reporting 7%–10% additional loss of productivity compared to lowrisk individuals. In addition, those who reported receiving medication and/or treatment for arthritis had a 2.5% excess productivity loss independently attributed to their arthritis, which equals approximately $1,250 per employee per year, or$5.4 million to the corporation. This arthritis effect was discernible in those with low and moderate levels of health risk, but was not as evident in those with high health risks; in that group, health-associated decrements in productivity were much larger. Arthritis is associated with work productivity loss. Disease management programs should focus on pain management and arthritis-associated health risks and comorbidities in order to significantly decrease arthritis-related losses in on-the-job productivity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63221/1/dis.2006.9.131.pd

The influence of transition metal solutes on dislocation core structure and values of Peierls stress and barrier in tungsten

Several transition metals were examined to evaluate their potential for improving the ductility of tungsten. The dislocation core structure and Peierls stress and barrier of $1/2$ screw dislocations in binary tungsten-transition metal alloys (W$_{1-x}$TM$_{x}$) were investigated using first principles electronic structure calculations. The periodic quadrupole approach was applied to model the structure of $1/2$ dislocation. Alloying with transition metals was modeled using the virtual crystal approximation and the applicability of this approach was assessed by calculating the equilibrium lattice parameter and elastic constants of the tungsten alloys. Reasonable agreement was obtained with experimental data and with results obtained from the conventional supercell approach. Increasing the concentration of a transition metal from the VIIIA group, i.e. the elements in columns headed by Fe, Co and Ni, leads to reduction of the $C^\prime$ elastic constant and increase of elastic anisotropy A=$C_{44}/C^\prime$. Alloying W with a group VIIIA transition metal changes the structure of the dislocation core from symmetric to asymmetric, similar to results obtained for W$_{1-x}$Re$_{x}$ alloys in the earlier work of Romaner {\it et al} (Phys. Rev. Lett. 104, 195503 (2010))\comments{\cite{WRECORE}}. In addition to a change in the core symmetry, the values of the Peierls stress and barrier are reduced. The latter effect could lead to increased ductility in a tungsten-based alloy\comments{\cite{WRECORE}}. Our results demonstrate that alloying with any of the transition metals from the VIIIA group should have similar effect as alloying with Re.Comment: 12 pages, 8 figures, 3 table

Exercise-induced reversal of age-related declines of oxidative reactions, mitochondrial yield, and flavins in skeletal muscle of the rat

The ability of gastrocnemius muscle homogenates to catalyze the oxidation of succinate, glutamate + malate, pyruvate + malate, palmitoyl-coenzyme A, decanoylcarnitine and palmitoylcarnitine in the presence of ADP decreased by approximately 32% in sedentary male Sprague-Dawley rats between the ages of 9 and 25 months. Following 21 weeks of treadmill training (running), such homogenates from 25-month-old animals catalyzed oxidations 55% more rapidly than those from 25-month-old sedentary rats, and 17% faster than those from 9-month-old sedentary rats. Total and peptide-bound flavin of gastrocnemius muscles also declined between 9 and 25 months of age and were elevated in the 25-month-old endurance trained rats to levels greater than both 9- and 25-month-old sedentary animals. The yield of protein in the mitochondrial fraction from the quadriceps femoris muscle decreased between 9 and 25 months and was restored to the 9-month level by endurance training. The kinetic characteristics of the isolated mitochondria were not influenced by age or exercise. These data indicate that 2-year-old rats retain the capacity to increase skeletal muscle oxidative capacity and mitochondrial population density in response to endurance training.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24891/1/0000318.pd

Skin Cancers Among Albinos at a University Teaching Hospital in Northwestern Tanzania: A Retrospective Review of 64 Cases.

Skin cancers are a major risk associated with albinism and are thought to be a major cause of death in African albinos. The challenges associated with the care of these patients are numerous and need to be addressed. The aim of this study was to outline the pattern and treatment outcome of skin cancers among albinos treated at our centre and to highlight challenges associated with the care of these patients and proffer solutions for improved outcome. This was a retrospective study of all albinos with a histopathological diagnosis of skin cancer seen at Bugando Medical Centre from March 2001 to February 2010. Data collected were analyzed using descriptive statistics. A total of 64 patients were studied. The male to female ratio was 1.5:1. The median age of patients was 30 years. The median duration of illness at presentation was 24 months. The commonest reason for late presentation was financial problem. Head and the neck was the most frequent site afflicted in 46(71.8%) patients. Squamous cell carcinoma was the most common histopathological type in 75% of cases. Surgical operation was the commonest modality of treatment in 60 (93.8%) patients. Radiotherapy was given in 24(37.5%) patients. Twenty-seven (42.2%) of the patients did not complete their treatment due to lack of funds. Local recurrence following surgical treatment was recorded in 6 (30.0%) patients. Only thirty-seven (61.7%) patients were available for follow-up at 6-12 months and the remaining patients were lost to follow-up. Skin cancers are the most common cancers among albinos in our environment. Albinism and exposure to ultraviolet light appears to be the most important risk factor in the development of these cancers. Late presentation and failure to complete treatment due to financial difficulties and lack of radiotherapy services at our centre are major challenges in the care of these patients. Early institution of preventive measures, early presentation and treatment, and follow-up should be encouraged in this population for better outcome

Tissue coenzyme Q (ubiquinone) and protein concentrations over the life span of the laboratory rat

The coenzyme Q (ubiquinone) concentrations of a number of tissues have been determined over the life span of the male laboratory rat. Coenzyme Q increased between 2 and 18 months and decreased significantly at 25 months in the heart and kidney, and the gastrocnemius, oblique and deep aspect (red) vastus lateralis muscles. The coenzyme Q concentration of liver increased over the life span, while it remained relatively constant in brain, lung, and the superficial aspect (white) of the vastus lateralis muscle. Data are also included for organ weights and protein contents of tissues over the life span. The various roles of coenzyme Q in cellular electron transfer and its regulation, energy conservation in oxidative phosphorylation, and its clinical efficacy in diseases of energy metabolism are discussed. It is hypothesized that coenzyme Q serves as a free radical quencher in the mitochondrion, a major site of free radical formation, in addition to its other roles in cellular energy metabolism, and that its cellular diminution may contribute to the loss of cellular function accompanying ageing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25514/1/0000055.pd