The role of tool geometry in process damped milling

The complex interaction between machining structural systems and the cutting process results in machining instability, so called chatter. In some milling scenarios, process damping is a useful phenomenon that can be exploited to mitigate chatter and hence improve productivity. In the present study, experiments are performed to evaluate the performance of process damped milling considering different tool geometries (edge radius, rake and relief angles and variable helix/pitch). The results clearly indicate that variable helix/pitch angles most significantly increase process damping performance. Additionally, increased cutting edge radius moderately improves process damping performance, while rake and relief angles have a smaller and closely coupled effect

Clinical performance and radiation dosimetry of no-carrier-added vs carrier-added 123I-metaiodobenzylguanidine (MIBG) for the assessment of cardiac sympathetic nerve activity

Purpose We hypothesized that assessment of myocardial sympathetic activity with no-carrier-added (nca) I-123-metaiodobenzylguanidine (MIBG) compared to carrier-added (ca) I-123-MIBG would lead to an improvement of clinical performance without major differences in radiation dosimetry. Methods In nine healthy volunteers, 15 min and 4 h planar thoracic scintigrams and conjugate whole-body scans were performed up to 48 h following intravenous injection of 185 MBq I-123-MIBG. The subjects were given both nca and ca I-123-MIBG. Early heart/mediastinal ratios (H/M), late H/M ratios and myocardial washout were calculated. The fraction of administered activity in ten source organs was quantified from the attenuation-corrected geometric mean counts in conjugate views. Radiation-absorbed doses were estimated with OLINDA/EXM software. Results Both early and late H/M were higher for nca I-123-MIBG (ca I-123-MIBG early H/M 2.46 +/- 0.15 vs nca I-123-MIBG 2.84 +/- 0.15, p = 0.001 and ca I-123-MIBG late H/M 2.69 +/- 0.14 vs nca I-123-MIBG 3.34 +/- 0.18, p = 0.002). Myocardial washout showed a longer retention time for nca I-123-MIBG (p <0.001). The effective dose equivalent (adult male model) for nca I-123-MIBG was similar to that for ca I-123-MIBG (0.025 +/- 0.002 mSv/MBq vs 0.026 +/- 0.002 mSv/MBq, p = 0.055, respectively). Conclusion No-carrier-added I-123-MIBG yields a higher relative myocardial uptake and is associated with a higher myocardial retention. This difference between nca I-123-MIBG and ca I-123-MIBG in myocardial uptake did not result in major differences in estimated absorbed doses. Therefore, nca I-123-MIBG is to be preferred over ca I-123-MIBG for the assessment of cardiac sympathetic activit

Aggressive vs. conservative phototherapy for infants with extremely low birth weight.

BACKGROUND: It is unclear whether aggressive phototherapy to prevent neurotoxic effects of bilirubin benefits or harms infants with extremely low birth weight (1000 g or less). METHODS: We randomly assigned 1974 infants with extremely low birth weight at 12 to 36 hours of age to undergo either aggressive or conservative phototherapy. The primary outcome was a composite of death or neurodevelopmental impairment determined for 91% of the infants by investigators who were unaware of the treatment assignments. RESULTS: Aggressive phototherapy, as compared with conservative phototherapy, significantly reduced the mean peak serum bilirubin level (7.0 vs. 9.8 mg per deciliter [120 vs. 168 micromol per liter], P\u3c0.01) but not the rate of the primary outcome (52% vs. 55%; relative risk, 0.94; 95% confidence interval [CI], 0.87 to 1.02; P=0.15). Aggressive phototherapy did reduce rates of neurodevelopmental impairment (26%, vs. 30% for conservative phototherapy; relative risk, 0.86; 95% CI, 0.74 to 0.99). Rates of death in the aggressive-phototherapy and conservative-phototherapy groups were 24% and 23%, respectively (relative risk, 1.05; 95% CI, 0.90 to 1.22). In preplanned subgroup analyses, the rates of death were 13% with aggressive phototherapy and 14% with conservative phototherapy for infants with a birth weight of 751 to 1000 g and 39% and 34%, respectively (relative risk, 1.13; 95% CI, 0.96 to 1.34), for infants with a birth weight of 501 to 750 g. CONCLUSIONS: Aggressive phototherapy did not significantly reduce the rate of death or neurodevelopmental impairment. The rate of neurodevelopmental impairment alone was significantly reduced with aggressive phototherapy. This reduction may be offset by an increase in mortality among infants weighing 501 to 750 g at birth. (ClinicalTrials.gov number, NCT00114543.

Coordinated Translocation of Mammalian Gli Proteins and Suppressor of Fused to the Primary Cilium

Intracellular transduction of Hedgehog (Hh) signals in mammals requires functional primary cilia. The Hh signaling effectors, the Gli family of transcription factors, and their negative regulator, Suppressor of Fused (Sufu), accumulate at the tips of cilia; however, the molecular mechanism regulating this localization remains elusive. In the current study, we show that the ciliary localization of mammalian Gli proteins depends on both their N-terminal domains and a central region lying C-terminal to the zinc-finger DNA-binding domains. Invertebrate Gli homologs Ci and Tra1, when over-expressed in ciliated mouse fibroblasts, fail to localize to the cilia, suggesting the lack of a vertebrate-specific structural feature required for ciliary localization. We further show that activation of protein kinase A (PKA) efficiently inhibits ciliary localization of Gli2 and Gli3, but only moderately affects the ciliary localization of Gli1. Interestingly, variants of Gli2 mimicking the phosphorylated or non-phosphorylated states of Gli2 are both localized to the cilia, and their ciliary localizations are subjected to the inhibitory effect of PKA activation, suggesting a likely indirect mechanism underlying the roles of PKA in Gli ciliary localization. Finally, we show that ciliary localization of Sufu is dependent on ciliary-localized Gli proteins, and is inhibited by PKA activation, suggesting a coordinated mechanism for the ciliary translocation of Sufu and Gli proteins

Individual, social, environmental, and physical environmental correlates with physical activity among Canadians: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>The identification of various individual, social and physical environmental factors affecting physical activity (PA) behavior in Canada can help in the development of more tailored intervention strategies for promoting higher PA levels in Canada. This study examined the influences of various individual, social and physical environmental factors on PA participation by gender, age and socioeconomic status, using data from the 2002 nationwide survey of the Physical Activity Monitor.</p> <p>Methods</p> <p>In 2002, 5,167 Canadians aged 15–79 years, selected by random-digit dialling from household-based telephone exchanges, completed a telephone survey. The short version of the International Physical Activity Questionnaire was used to collect information on total physical activity. The effects of socio-economical status, self-rated health, self-efficacy, intention, perceived barriers to PA, health benefits of PA, social support, and facility availability on PA level were examined by multiple logistic regression analyses.</p> <p>Results</p> <p>Self-efficacy and intention were the strongest correlates and had the greatest effect on PA. Family income, self-rated health and perceived barriers were also consistently associated with PA. The effects of the perceived health benefits, education and family income were more salient to older people, whereas the influence of education was more important to women and the influence of perceived barriers was more salient to women and younger people. Facility availability was more strongly associated with PA among people with a university degree than among people with a lower education level. However, social support was not significantly related to PA in any subgroup.</p> <p>Conclusion</p> <p>This study suggests that PA promotion strategies should be tailored to enhance people's confidence to engage in PA, motivate people to be more active, educate people on PA's health benefits and reduce barriers, as well as target different factors for men and women and for differing socio-economic and demographic groups.</p

Nonadherence with Immunosuppressive Drugs: Us Compared with European Kidney Transplant Recipients

Background-System factors increasingly are suggested as important yet understudied correlates of nonadherence.Objective-To explore the relationship between healthcare system and prevalence of nonadherence with immunosuppressive regimen by studying variation in non-adherence between European and US kidney transplant recipients and as well as nonadherence in European countries.Methods-We performed a secondary data analysis on data collected in 3 independent cross-sectional studies using comparable methodology including patients from the United States, the Netherlands, Belgium, and Switzerland. Nonadherence was measured using 1 item of the Siegal questionnaire. Patients were categorized as nonadherent if they reported missing a dose of immunosuppression in the last 4 weeks. Analyses were performed by multiple mixed logistic regression, with center as a random effect and clinical and demographical differences between groups as fixed effects.Results-1563 US and 614 European patients from 3 different countries (Belgium [n=187], the Netherlands [n=85], and Switzerland [n=342]) were included. Prevalence of nonadherence in the United States and Europe was 19.3% and 13.2.%, respectively. This higher nonadherence in US patients was confirmed in a multiple logistic regression analysis (OR=1.78; 95% CI, 1.10-2.89). Nonadherence differed between Belgium (16%) and the Netherlands (14.1%) (OR=0.27; 95% CI, 0.09-0.80) and between Belgium and Switzerland (11.4%; OR=0.17; 95% CI, 0.0-0.42).Conclusion- This is the first study showing differences in prevalence of nonadherence between European and US patients and among European patients. Further research should aim at unraveling the dynamics explaining these differences