25 research outputs found

    A Musical instrument in MEMS

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    In this work we describe a MEMS instrument that resonates at audible frequencies, and with which music can be made. The sounds are generated by mechanical resonators and capacitive displacement sensors. Damping by air scales unfavourably for generating audible frequencies with small devices. Therefore a vacuum of 1.5 mbar is used to increase the quality factor and consequently the duration of the sounds to around 0.25 s. The instrument will be demonstrated during the MME 2010 conference opening, in a musical composition especially made for the occasion

    A Prediction Model for Neonatal Mortality in Low- and Middle-income Countries: An Analysis of Data from Population Surveillance Sites in India, Nepal and Bangladesh

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    Background: In poor settings, where many births and neonatal deaths occur at home, prediction models of neonatal mortality in the general population can aid public-health policy-making. No such models are available in the international literature. We developed and validated a prediction model for neonatal mortality in the general population in India, Nepal and Bangladesh. Methods: Using data (49 632 live births, 1742 neonatal deaths) from rural and urban surveillance sites in South Asia, we developed regression models to predict the risk of neonatal death with characteristics known at (i) the start of pregnancy, (ii) start of delivery and (iii) 5 minutes post partum. We assessed the models’ discriminative ability by the area under the receiver operating characteristic curve (AUC), using cross-validation between sites. Results: At the start of pregnancy, predictive ability was moderate {AUC 0.59 [95% confidence interval (CI) 0.58–0.61]} and predictors of neonatal death were low maternal education and economic status, short birth interval, primigravida, and young and advanced maternal age. At the start of delivery, predictive ability was considerably better [AUC 0.73 (95% CI 0.70–0.76)] and prematurity and multiple pregnancy were strong predictors of death. At 5 minutes post partum, predictive ability was good [AUC: 0.85 (95% CI 0.80–0.89)]; very strong predictors were multiple birth, prematurity and a poor condition of the infant at 5 minutes. Conclusions: We developed good performing prediction models for neonatal mortality. Neonatal deaths are highly concentrated in a small group of high-risk infants, even in poor settings in South Asia. Risk assessment, as supported by our models, can be used as a basis for improving community- and facility-based newborn care and prevention strategies in poor settings

    Health-related quality of life after isolated limb perfusion compared to extended resection, or amputation for locally advanced extremity sarcoma:Is a limb salvage strategy worth the effort?

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    Introduction: The aim of this study was to compare long-term patient reported outcomes (PROs) in patients with locally advanced extremity soft tissue sarcoma (eSTS) after isolated limb perfusion followed by resection (IR), compared to extended resection (ER), primary amputation (A) or secondary amputation after IR (IR-A). Methods: Patients were selected from the respondents of a multi-institutional cross-sectional cohort survivorship study (SURVSARC) conducted among sarcoma survivors registered in the Netherlands Cancer Registry (NCR), 2–10 years after diagnosis. Used PROs were the EORTC QLQ-C30, the Cancer worry scale (CWS), the Hospital Anxiety and Depression Scale (HADS), and the Toronto Extremity Salvage Score (TESS). Results: We identified 97 eSTS survivors: IR = 20, ER = 49, A = 20, IR-A = 8. While there were no differences in PROs between IR and ER, results showed better functioning and functionality in both groups versus the amputation groups. The amputation groups scored significantly lower on physical functioning (A = 62.7, IR-A = 65.7 versus IR = 78.0, ER = 82.7, p = 0.001) and role functioning (A = 67.5, IR-A = 52.8 versus IR = 79.2, ER = 80.6, p = 0.039), both EORTC QLQ-C30 scales. Also for the TESS, the scores were significantly lower for the amputation groups compared to the limb sparing groups (upper extremity p = 0.007 with A = 68.9, IR-A = 71.6 versus IR = 93.3, ER = 91.1; lower extremity p < 0.001 with A = 72.2, IR-A50.9 versus IR = 84.5 and ER = 85.5). There were no significant differences between the groups on cancer worry, anxiety and depression. Conclusion: HRQoL in eSTS survivors treated with IR or ER is equal; for maintenance of physical functioning and functionality IR and ER outperform an amputation

    A prediction model for neonatal mortality in low- and middle-income countries: an analysis of data from population surveillance sites in India, Nepal and Bangladesh.

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    Abstract BACKGROUND: In poor settings, where many births and neonatal deaths occur at home, prediction models of neonatal mortality in the general population can aid public-health policy-making. No such models are available in the international literature. We developed and validated a prediction model for neonatal mortality in the general population in India, Nepal and Bangladesh. METHODS: Using data (49 632 live births, 1742 neonatal deaths) from rural and urban surveillance sites in South Asia, we developed regression models to predict the risk of neonatal death with characteristics known at (i) the start of pregnancy, (ii) start of delivery and (iii) 5 minutes post partum. We assessed the models' discriminative ability by the area under the receiver operating characteristic curve (AUC), using cross-validation between sites. RESULTS: At the start of pregnancy, predictive ability was moderate {AUC 0.59 [95% confidence interval (CI) 0.58-0.61]} and predictors of neonatal death were low maternal education and economic status, short birth interval, primigravida, and young and advanced maternal age. At the start of delivery, predictive ability was considerably better [AUC 0.73 (95% CI 0.70-0.76)] and prematurity and multiple pregnancy were strong predictors of death. At 5 minutes post partum, predictive ability was good [AUC: 0.85 (95% CI 0.80-0.89)]; very strong predictors were multiple birth, prematurity and a poor condition of the infant at 5 minutes. CONCLUSIONS: We developed good performing prediction models for neonatal mortality. Neonatal deaths are highly concentrated in a small group of high-risk infants, even in poor settings in South Asia. Risk assessment, as supported by our models, can be used as a basis for improving community- and facility-based newborn care and prevention strategies in poor settings

    Wastewater-Based Epidemiology: Global Collaborative to Maximize Contributions in the Fight against COVID-19

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    Severe acute respiratory syndrome coronavirus 2 (SARSCoV-2), a novel member of the Coronaviridae family, has been identified as the etiologic agent of an ongoing pandemic of severe pneumonia known as COVID-19. To date there have been millions of cases of COVID-19 diagnosed in 184 countries with case fatality rates ranging from 1.8% in Germany to 12.5% in Italy. Limited diagnostic testing capacity and asymptomatic and oligosymptomatic infections result in significant uncertainty in the estimated extent of SARS-CoV-2 infection. Recent reports have documented that infection with SARS-CoV-2 is accompanied by persistent shedding of virus RNA in feces in 27% to 89% of patients at densities from 0.8 to 7.5 log10 gene copies per gram. The presence of SARS-CoV-2 RNA in feces raises the potential to survey sewage for virus RNA to inform epidemiological monitoring of COVID-19, which we refer to as wastewater-based epidemiology (WBE), but is also known as environmental surveillance

    Effects on imaging by tilting electrostatic actuators in electron microscopy

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    In this paper we investigate the influence of tilted electrostatic actuators on the imaging in electron microscopes. Previous studies have shown image deformation by electrostatic actuation in electron microscopes, and suggested a strong influence of the tilt angle on the deflection of the electron beam. Our model suggests an influence of 1 \mu m/^\circ of the tilt angle on the amplitude of deflection. Preliminary experimental results indicate an influence of the angle on the amplitude of deflection, but the observed effect is two orders of magnitude smaller than simulations predict. However, there are still some variables we have not explored that might influence the strength of the influence of tilt

    Effects on imaging by tilting electrostatic actuators in electron microscopy

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    In this paper we investigate the influence of tilted electrostatic actuators on the imaging in electron microscopes. Previous studies have shown image deformation by electrostatic actuation in electron microscopes, and suggested a strong influence of the tilt angle on the deflection of the electron beam. Our model suggests an influence of 1 \mu m/^\circ of the tilt angle on the amplitude of deflection. Preliminary experimental results indicate an influence of the angle on the amplitude of deflection, but the observed effect is two orders of magnitude smaller than simulations predict. However, there are still some variables we have not explored that might influence the strength of the influence of tilt

    Endoscope disinfection and its pitfalls--requirement for retrograde surveillance cultures.

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    Contains fulltext : 70415.pdf (publisher's version ) (Closed access)BACKGROUND AND STUDY AIMS: Several endoscopy-related outbreaks of infection have been reported in recent years. For early recognition of inadequate disinfection of endoscopes we designed a microbiological surveillance system to evaluate the efficacy of the cleaning and disinfection procedure, and to trace disinfection problems to individual endoscopes or washer-disinfectors. METHODS: Our surveillance protocol included anterograde and retrograde sampling, a decision algorithm, genetic fingerprinting, and scanning electron microscopy. RESULTS: Over a period of 29 months we found an increasing number of patient-ready endoscopes testing positive for Candida species other than albicans, especially C. parapsilosis. These yeasts were also isolated from the washer-disinfectors. The number of positive tests for Candida species varied from 1 out of 21 to 14 out of 27 samples from nine frequently used endoscopes. The number of colony-forming units per milliliter ranged from 1 - 10 to 3000 for endoscopes and 0.002 to 0.06 for the washer disinfectors. DNA fingerprinting was not able to discriminate different strains within C. parapsilosis. CONCLUSIONS: Our protocol was able to detect a structural problem in the endoscope disinfection process. Retrograde sampling was crucial for this purpose, because it has much higher sensitivity than anterograde sampling. Endoscopes with damaged working channels are probably the source of the contamination problem with Candida species

    Contamination on AMS Sample Targets by Modern Carbon is Inevitable

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    Accelerator mass spectrometry (AMS) measurements of the radiocarbon content in very old samples are often challenging and carry large relative uncertainties due to possible contaminations acquired during the preparation and storage steps. In case of such old samples, the natural surrounding levels of C-14 from gases in the atmosphere, which may well be the source of contamination among others, are 2-3 orders of magnitude higher than the samples themselves. Hence, serious efforts are taken during the preparation steps to have the samples pristine until measurements are performed. As samples often have to be temporarily stored until AMS measurements can be performed, storage conditions also become extremely crucial. Here we describe an assessment of this process of contamination in background AMS samples. Samples, both as pressed graphite (on AMS targets) and graphite powder, were stored in various storage conditions (CO2-spiked air) to investigate the extent of contamination. The experiments clearly show that the pressed targets are more vulnerable to contamination than the unpressed graphite. Experiments conducted with enriched CO2-spiked laboratory air also reveal that the contaminating carbon is not only limited to the target surface but also penetrates into the matrix. A combination of measurements on understanding the chemical nature of the graphitization product, combined with long-available knowledge on "adventitious carbon" from the surface science community, brought us to the conclusion that contamination is to a certain extent inevitable. However, it can be minimized, and should be dealt with by sputter-cleaning the samples individually before the actual measurement

    Reduction of time-varying nanotesla magnetic fields from electric power lines by twisting

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    Time-varying magnetic fields generated by electrical power lines in the laboratory can disturb electron microscope imaging. Modern microscopes require these fields to be below 10 nT [2]. We calculated and measured magnetic fields from straight and twisted current-carrying wires, and show that without twisting, this value cannot be reached
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