16 research outputs found
Relationship between microstructure and fracture types in a UNS S32205 duplex stainless steel
Duplex stainless steels are susceptible to the formation of sigma phase at high temperature which could potentially be responsible for catastrophic service failure of components. Thermal treatments were applied to duplex stainless steels in order to promote the precipitation of different fractions of sigma phase into a ferrite-austenite microstructure. Quantitative image analysis was employed to characterize the microstructure and Charpy impact tests were used in order to evaluate the mechanical degradation caused by sigma phase presence. The fracture morphology of the Charpy test specimens were thoroughly observed in SEM, looking for a correlation between the microstructure and the fracture types in UNS S32205 duplex stainless steel. The main conclusion is the strong embrittlement effect of sigma phase since it is possible to observe a transition from transgranular fracture to intergranular fracture as increases the percentage of sigma phase. Thus, the mixed modes of fracture are predominant in the present study with high dependence on sigma phase percentages obtained by different thermal treatments
Need for weight management in Switzerland: findings from National Blood Pressure Week 2009
<p>Abstract</p> <p>Background</p> <p>The Swiss Health Survey (SHS) provides the only source of data for monitoring overweight and obesity in the general population in Switzerland. However, this survey reports body mass index (BMI) based on self-reported height and weight, and is therefore subject to measurement errors. Moreover, it is not possible to differentiate between overall and abdominal overweight. In this study, we aimed to gain a better understanding of the need for weight management in the general population of Switzerland by exploring and comparing prevalence rates of BMI and waist circumference (WC) based on physical measurements by trained observers, based on data from the 2009 National Blood Pressure Week (NBPW).</p> <p>Methods</p> <p>Sample selection was based on a one-stage cluster design. A total of 385 pharmacies representing 3,600 subjects were randomly selected from pharmacies participating in NBPW. BMI measures based on physical weight and height (NBPW) were compared with self-reported BMI measures from the SHS. BMI and WC measurements from NBPW were then used to produce population estimates of overweight and obesity.</p> <p>Results</p> <p>BMI-based overall prevalence of overweight and obesity was 43.6%, which was 4.7% higher than the value based on the respective SHS data. Overweight and obesity were more common in men (54.3%) than in women (33.5%). However, the overall prevalence of increased WC in the general population was estimated to be 64.4%, with more women (68.4%) than men (60.1%) exhibiting a WC above the threshold. The prevalence of subjects requiring weight management in the Swiss population remained high, even after adjusting WC for false positive and negative cases.</p> <p>Conclusions</p> <p>Firstly, it may be more appropriate for health promotion programs to address the wider group identified by WC, which includes subjects who need to reduce their weight, or gain no further weight. Secondly, the gender differences are reversed depending on the use of WC or BMI to identify subjects suitable for health promotion programs; more women than men are identified by WC, and more men than women using BMI. These differences should be accounted for in gender-specific health promotion programs.</p
Noise-Driven Stem Cell and Progenitor Population Dynamics
BACKGROUND: The balance between maintenance of the stem cell state and terminal differentiation is influenced by the cellular environment. The switching between these states has long been understood as a transition between attractor states of a molecular network. Herein, stochastic fluctuations are either suppressed or can trigger the transition, but they do not actually determine the attractor states. METHODOLOGY/PRINCIPAL FINDINGS: We present a novel mathematical concept in which stem cell and progenitor population dynamics are described as a probabilistic process that arises from cell proliferation and small fluctuations in the state of differentiation. These state fluctuations reflect random transitions between different activation patterns of the underlying regulatory network. Importantly, the associated noise amplitudes are state-dependent and set by the environment. Their variability determines the attractor states, and thus actually governs population dynamics. This model quantitatively reproduces the observed dynamics of differentiation and dedifferentiation in promyelocytic precursor cells. CONCLUSIONS/SIGNIFICANCE: Consequently, state-specific noise modulation by external signals can be instrumental in controlling stem cell and progenitor population dynamics. We propose follow-up experiments for quantifying the imprinting influence of the environment on cellular noise regulation.Engineering and Applied SciencesOther Research Uni
The Palliative Care-Promoting Access and Improvement of the Cancer Experience (PC-PAICE) Project in India: A Multisite International Quality Improvement Collaborative.
Mentors at seven U.S. and Australian academic institutions initially partnered with seven leading Indian academic palliative care and cancer centers in 2017 to undertake a program combining remote and in-person mentorship, didactic instruction, and project-based learning in quality improvement (QI). From its inception in 2017 to 2020, the Palliative Care-Promoting Accesst and Improvement of the Cancer Experience Program conducted three cohorts for capacity building of 22 Indian palliative care and cancer programs. Indian leadership established a Mumbai QI training hub in 2019 with philanthropic support. In 2020, the project which is now named Enable Quality, Improve Patient care - India (EQuIP-India) focuses on both palliative care and cancer teams. EQuIP-India now leads ongoing Indian national collaboratives and training in QI and is integrated into India's National Cancer Grid. Palliative Care-Promoting Accesst and Improvement of the Cancer Experience demonstrates a feasible model of international collaboration and capacity building in palliative care and cancer QI. It is one of the several networked and blended learning approaches with potential for rapid scaling of evidence-based practices