Robust Control Architecture for Waste Heat Harvesting with Non-Inverting Buck-Boost Converter

Thermoelectric generators (TEG) can be used to harvest wasted heat. TEGs are characterized by a wide output voltage range and a considerable output resistance leading to a maximum power point dependent on the working temperature. Non-Inverting Buck-Boost converter is used to manage, from one side, the wide voltage range, and from the other a battery. This article investigates a robust control architecture to recover the maximum energy from the exhaust's heat avoiding instability issues and maximizing converter efficiency

Capacitive Displacement Sensor for a Self-Sensing Shock-Absorber Piston-Cylinder Mechanism

Measurement of piston displacement is a common problem for any pneumatic or hydraulic device, like shock-absorber. Direct measurements are not always feasible because of mechanical constraints; most recent techniques rely on magnetic phenomena, introducing considerable complexity. In an attempt to achieve an economical and feasible solution, an intrinsic capacitive sensor is developed. Such sensors measure the capacitance between piston and cylinder, which is directly proportional to displacement. It is developed an oscillator stage to measure the unknown capacitance. The oscillator’s output is acquired by a microcontroller, conditioned and transformed into the estimated displacement. This paper focuses on the design methodology of the measurement stage, highlighting tradeoffs and optimizations. The sensor was developed for an automotive application in a commercial shock absorber: however, it can be extended to other devices where proper electrical isolation between cylinder and piston is provided. Mathematical models and experimental results are reported compared to a commercial position sensor

A NOVEL HUMAN-IN-THE-LOOP TESTING FACILITY FOR SPACE APPLICATIONS

To analyse the interaction between the piloting astronaut and lunar lander dynamics while landing on the south pole of the moon, The European Space Agency (ESA) has initiated together with Thales Alenia Space (TAS), GMV Aerospace and Defence SAU (GMV) and The German Aerospace Centre (DLR) a project entitled “Human-In-the-Loop Flight Vehicle Engineering“. For this purpose, the DLR Robotic Motion Simulator (RMS) was transformed into a novel Humanin- the-Loop testing facility for space applications. The RMS represents a new class of motion simulators being currently developed at DLR that allow for extreme tilt angles and manoeuvres. It is based on an industrial 6 Degrees of Freedom (DOF) robot arm that is mounted onto a 10m long linear axis. The system therefore has a redundant 7 DOF architecture to induce motion cues onto an attached simulator cell. A highly modular simulator cell was configured for landing on the moon with three touch screens that were used to interact with the Human Machine Interface (HMI), Throttle and Joystick instruments, a virtual window to the outside, a headset and a surveillance camera for the piloting astronaut. The joystick features 3 DOFs and the throttle features adjustable damping along with many buttons that were used as inputs to the simulation. For the Moon landing scenery, a highresolution lunar crater visualization based on DLR’s Visualization 2 library was developed. Rocks and Boulders were distributed over the surface of the simulated region of the moon according to the Size-Frequency Distribution (SFD) for moon craters. ESA astronaut and test pilot Roberto Vittori tested various lunar landing manoeuvres using flight controls algorithms developed in HITL and motion simulation, provided by GMV, and was able to experience how the spacecraft behaves in critical phases of the lunar landing and intervene to control it. In one scenario the Landing GNC Automatic Mode was set to a landing zone where there were boulders. Vittori then had the option to intervene within a certain time window and, using touchscreens, select an alternative landing site. If needed, he was able to switch to Astronaut Manual Mode and pilot the lunar lander manually as it descended onto the lunar floor. Two Manual Control strategies were tested: Full Force / Torque Control and Rate Control. Two Motion cueing algorithms for low gravity environments were tested. Further experiments are planned

Platelet Rich Plasma stimulates human hair growth in vitro

Several factors are involved in hair growth and cycling (Buffoli et al., 2013). Platelet concentrates have a new important role in regenerative medicine and thus in dermatology, oral, plastic and orthopaedic surgery and hair growth (Franco et al., 2012). In this study we evaluated in vitro the effects of Platelet-Rich Plasma (PRP), an autologous platelet preparation, on hair growth. In particular, we compared four different culture media (Philpott et al., 1990): 1-William’s E culture medium with supplemented factors; 2-William’s E culture medium with supplemented factors and Platelet Rich Plasma; 3-William’s E culture medium without supplemented factors; 4-William’s E culture medium without supplemented factors but with PRP. Hair shaft elongation was measured at 0, 24, 48, 72 and 96 hours: digitally fixed images of slices were analyzed using an image analyzer considering as measurable portion the shaft part between the bulb upper border and the top of the hair end. The values obtained were used to calculate the percentage of elongation for each time. Growth in hair cultured with William’s E medium with supplemented factors and PRP resulted higher with respect to the other media. Moreover, these results suggest that PRP stimulates human hair growth in vitro

A randomized, double-blind, placebo-and active-controlled, half-head study to evaluate the effects of platelet-rich plasma on alopecia areata

Summary Background Alopecia areata (AA) is a common autoimmune condition, causing inflammation-induced hair loss. This disease has very limited treatment possibilities, and no treatment is either curative or preventive. Platelet-rich plasma (PRP) has emerged as a new treatment modality in dermatology, and preliminary evidence has suggested that it might have a beneficial role in hair growth. Objectives To evaluate the efficacy and safety of PRP for the treatment of AA in a randomized, double-blind, placebo-and active-controlled, half-head, parallelgroup study. Methods Forty-five patients with AA were randomized to receive intralesional injections of PRP, triamcinolone acetonide (TrA) or placebo on one half of their scalp. The other half was not treated. Three treatments were given for each patient, with intervals of 1 month. The endpoints were hair regrowth, hair dystrophy as measured by dermoscopy, burning or itching sensation, and cell proliferation as measured by Ki-67 evaluation. Patients were followed for 1 year. Results PRP was found to increase hair regrowth significantly and to decrease hair dystrophy and burning or itching sensation compared with TrA or placebo. Ki-67 levels, which served as markers for cell proliferation, were significantly higher with PRP. No side-effects were noted during treatment. Conclusions This pilot study, which is the first to investigate the effects of PRP on AA, suggests that PRP may serve as a safe and effective treatment option in AA, and calls for more extensive controlled studies with this method

Gene Expression Profiling Predicts Survival in Conventional Renal Cell Carcinoma

BACKGROUND: Conventional renal cell carcinoma (cRCC) accounts for most of the deaths due to kidney cancer. Tumor stage, grade, and patient performance status are used currently to predict survival after surgery. Our goal was to identify gene expression features, using comprehensive gene expression profiling, that correlate with survival. METHODS AND FINDINGS: Gene expression profiles were determined in 177 primary cRCCs using DNA microarrays. Unsupervised hierarchical clustering analysis segregated cRCC into five gene expression subgroups. Expression subgroup was correlated with survival in long-term follow-up and was independent of grade, stage, and performance status. The tumors were then divided evenly into training and test sets that were balanced for grade, stage, performance status, and length of follow-up. A semisupervised learning algorithm (supervised principal components analysis) was applied to identify transcripts whose expression was associated with survival in the training set, and the performance of this gene expression-based survival predictor was assessed using the test set. With this method, we identified 259 genes that accurately predicted disease-specific survival among patients in the independent validation group (p < 0.001). In multivariate analysis, the gene expression predictor was a strong predictor of survival independent of tumor stage, grade, and performance status (p < 0.001). CONCLUSIONS: cRCC displays molecular heterogeneity and can be separated into gene expression subgroups that correlate with survival after surgery. We have identified a set of 259 genes that predict survival after surgery independent of clinical prognostic factors

Systematic Evaluation of the Prognostic Impact and Intratumour Heterogeneity of Clear Cell Renal Cell Carcinoma Biomarkers

AbstractBackgroundCandidate biomarkers have been identified for clear cell renal cell carcinoma (ccRCC) patients, but most have not been validated.ObjectiveTo validate published ccRCC prognostic biomarkers in an independent patient cohort and to assess intratumour heterogeneity (ITH) of the most promising markers to guide biomarker optimisation.Design, setting, and participantsCancer-specific survival (CSS) for each of 28 identified genetic or transcriptomic biomarkers was assessed in 350 ccRCC patients. ITH was interrogated in a multiregion biopsy data set of 10 ccRCCs.Outcome measurements and statistical analysisBiomarker association with CSS was analysed by univariate and multivariate analyses.Results and limitationsA total of 17 of 28 biomarkers (TP53 mutations; amplifications of chromosomes 8q, 12, 20q11.21q13.32, and 20 and deletions of 4p, 9p, 9p21.3p24.1, and 22q; low EDNRB and TSPAN7 expression and six gene expression signatures) were validated as predictors of poor CSS in univariate analysis. Tumour stage and the ccB expression signature were the only independent predictors in multivariate analysis. ITH of the ccB signature was identified in 8 of 10 tumours. Several genetic alterations that were significant in univariate analysis were enriched, and chromosomal instability indices were increased in samples expressing the ccB signature. The study may be underpowered to validate low-prevalence biomarkers.ConclusionsThe ccB signature was the only independent prognostic biomarker. Enrichment of multiple poor prognosis genetic alterations in ccB samples indicated that several events may be required to establish this aggressive phenotype, catalysed in some tumours by chromosomal instability. Multiregion assessment may improve the precision of this biomarker.Patient summaryWe evaluated the ability of published biomarkers to predict the survival of patients with clear cell kidney cancer in an independent patient cohort. Only one molecular test adds prognostic information to routine clinical assessments. This marker showed good and poor prognosis results within most individual cancers. Future biomarkers need to consider variation within tumours to improve accuracy