264 research outputs found

    Enabling low-cost particulate matter measurement for participatory sensing scenarios

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    Abstract. This paper presents a mobile, low-cost particulate matter sensing approach for the use in Participatory Sensing scenarios. It shows that cheap commercial off-the-shelf (COTS) dust sensors can be used in distributed or mobile personal measurement devices at a cost one to two orders of magnitude lower than that of current hand-held solutions, while reaching meaningful accuracy. We conducted a series of experiments to juxtapose the performance of a gauged high-accuracy measurement de-vice and a cheap COTS sensor that we fitted on a Bluetooth-enabled sensor module that can be interconnected with a mobile phone. Cal-ibration and processing procedures using multi-sensor data fusion are presented, that perform very well in lab situations and show practically relevant results in a realistic setting. An on-the-fly calibration correc-tion step is proposed to address remaining issues by taking advantage of co-located measurements in Participatory Sensing scenarios. By sharing few measurement across devices, a high measurement accuracy can b

    Should We Perform Old-For-Old Kidney Transplantation during the COVID-19 Pandemic? The Risk for Post-Operative Intensive Stay

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    Health care systems worldwide have been facing major challenges since the outbreak of the SARS-CoV-2 pandemic. Kidney transplantation (KT) has been tremendously affected due to limited personal protective equipment (PPE) and intensive care unit (ICU) capacities. To provide valid information on risk factors for ICU admission in a high-risk cohort of old kidney recipients from old donors in the Eurotransplant Senior Program (ESP), we retrospectively conducted a bi-centric analysis. Overall, 17 (16.2%) patients out of 105 KTs were admitted to the ICU. They had a lower BMI, and both coronary artery disease (CAD) and hypertensive nephropathy were more frequent. A risk model combining BMI, CAD and hypertensive nephropathy gained a sensitivity of 94.1% and a negative predictive value of 97.8%, rendering it a valuable search test, but with low specificity (51.1%). ICU admission also proved to be an excellent parameter identifying patients at risk for short patient and graft survivals. Patients admitted to the ICU had shorter patient (1-year 57% vs. 90%) and graft (5-year 49% vs. 77%) survival. To conclude, potential kidney recipients with a low BMI, CAD and hypertensive nephropathy should only be transplanted in the ESP in times of SARS-CoV-2 pandemic if the local health situation can provide sufficient ICU capacities

    Distribution of Aortic Root Calcium in Relation to Frame Expansion and Paravalvular Leakage After Transcatheter Aortic Valve Implantation (TAVI):An Observational Study Using a Patient-specific Contrast Attenuation Coefficient for Calcium Definition and Independent Core Lab Analysis of Paravalvular Leakage

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    BACKGROUND: Calcium is a determinant of paravalvular leakage (PVL) after transcatheter aortic valve implantation (TAVI). This is based on a fixed contrast attenuation value while X-ray attenuation is patient-dependent and without considering frame expansion and PVL location. We examined the role of calcium in (site-specific) PVL after TAVI using a patient-specific contrast attenuation coefficient combined with frame expansion. METHODS: 57 patients were included with baseline CT, post-TAVI transthoracic echocardiography and rotational angiography (R-angio). Calcium load was assessed using a patient-specific contrast attenuation coefficient. Baseline CT and post-TAVI R-angio were fused to assess frame expansion. PVL was assessed by a core lab. RESULTS: Overall, the highest calcium load was at the non-coronary-cusp-region (NCR, 436 mm(3)) vs. the right-coronary-cusp-region (RCR, 233 mm(3)) and the left-coronary-cusp-region (LCR, 244 mm(3)), p < 0.001. Calcium load was higher in patients with vs. without PVL (1,137 vs. 742 mm(3), p = 0.012) and was an independent predictor of PVL (odds ratio, 4.83, p = 0.004). PVL was seen most often in the LCR (39% vs. 21% [RCR] and 19% [NCR]). The degree of frame expansion was 71% at the NCR, 70% at the RCR and 74% at the LCR without difference between patients with or without PVL. CONCLUSIONS: Calcium load was higher in patients with PVL and was an independent predictor of PVL. While calcium was predominantly seen at the NCR, PVL was most often at the LCR. These findings indicate that in addition to calcium, specific anatomic features play a role in PVL after TAVI

    Oxidative stress and inflammation distinctly drive molecular mechanisms of diastolic dysfunction and remodeling in female and male heart failure with preserved ejection fraction rats

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    Heart failure with preserved ejection fraction (HFpEF) is a complex cardiovascular insufficiency syndrome presenting with an ejection fraction (EF) of greater than 50% along with different proinflammatory and metabolic co-morbidities. Despite previous work provided key insights into our understanding of HFpEF, effective treatments are still limited. In the current study we attempted to unravel the molecular basis of sex-dependent differences in HFpEF pathology. We analyzed left ventricular samples from 1-year-old female and male transgenic (TG) rats homozygous for the rat Ren-2 renin gene (mRen2) characterized with hypertension and diastolic dysfunction and compared it to age-matched female and male wild type rats (WT) served as control. Cardiomyocytes from female and male TG rats exhibited an elevated titin-based stiffness (Fpassive), which was corrected to control level upon treatment with reduced glutathione indicating titin oxidation. This was accompanied with high levels of oxidative stress in TG rats with more prominent effects in female group. In vitro supplementation with heat shock proteins (HSPs) reversed the elevated Fpassive indicating restoration of their cytoprotective function. Furthermore, the TG group exhibited high levels of proinflammatory cytokines with significant alterations in apoptotic and autophagy pathways in both sexes. Distinct alterations in the expression of several proteins between both sexes suggest their differential impact on disease development and necessitate distinct treatment options. Hence, our data suggested that oxidative stress and inflammation distinctly drive diastolic dysfunction and remodeling in female and male rats with HFpEF and that the sex-dependent mechanisms contribute to HF pathology

    Prevalence and consequences of noncardiac incidental findings on preprocedural imaging in the workup for transcatheter aortic valve implantation, renal sympathetic denervation, or MitraClip implantation

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    Background: Dedicated data on the prevalence of incidental findings (IF) stratified according to overall clinical relevance and their subsequent correlation to outcome are lacking. The aim of the present study was to describe the prevalence and consequences of noncardiac IF on computed tomography or magnetic resonance imaging in the workup for interventional cardiovascular procedures. Methods: A total of 916 patients underwent preprocedural computed tomography or magnetic resonance imaging in the workup for transcatheter aortic valve implantation (TAVI), renal sympathetic denervation (RDN), or MitraClip implantation. Results: IF were found in 395 of 916 patients (43.1%), with an average of 1.8 IF per patient. Classifying the IF resulted in 155 patients with minor, 171 patients with moderate, and 69 patients with major IF. The intended procedure was delayed or canceled in only 15 of 916 (1.6%) of the patients because of the presence of potential malignant IF. In patients that did undergo the intended procedure (n = 774), the presence of a moderate or major IF (23.8%) did not impact 1-year mortality compared to no or minor IF (adjusted HR 0.90, 95% CI 0.56-1.44, P value =.65). These findings were consistent among patients referred for TAVI, RDN, or MitraClip. Conclusions: IF are frequent in patients referred for cardiovascular procedures. IF did not result in a delay or cancellation of the intended procedure in the vast majority of cases, irrespective of their clinical relevance. The presence of a major or moderate IF did not significantly impact 1-year mortality

    Pydna: a simulation and documentation tool for DNA assembly strategies using python

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    Background: Recent advances in synthetic biology have provided tools to efficiently construct complex DNA molecules which are an important part of many molecular biology and biotechnology projects. The planning of such constructs has traditionally been done manually using a DNA sequence editor which becomes error-prone as scale and complexity of the construction increase. A human-readable formal description of cloning and assembly strategies, which also allows for automatic computer simulation and verification, would therefore be a valuable tool.Results: We have developed pydna, an extensible, free and open source Python library for simulating basic molecular biology DNA unit operations such as restriction digestion, ligation, PCR, primer design, Gibson assembly and homologous recombination. A cloning strategy expressed as a pydna script provides a description that is complete, unambiguous and stable. Execution of the script automatically yields the sequence of the final molecule(s) and that of any intermediate constructs. Pydna has been designed to be understandable for biologists with limited programming skills by providing interfaces that are semantically similar to the description of molecular biology unit operations found in literature.Conclusions: Pydna simplifies both the planning and sharing of cloning strategies and is especially useful for complex or combinatorial DNA molecule construction. An important difference compared to existing tools with similar goals is the use of Python instead of a specifically constructed language, providing a simulation environment that is more flexible and extensible by the user.Thanks to Dr. Aric Hagberg Los Alamos National Laboratory, U.S.A and Sergio Simoes, Universidade de Sao Paulo, Brasil for help with NetworkX and graph theory in general. Thanks to Henrik Bengtsson, Dept of Epidemiology & Biostatistics, University of California San Francisco, U.S.A. for critical reading of the manuscript. Thanks to the 2013 Bioinformatics 6605 N4 students A. Coelho, A. Faria, A. Neves D. Yelshyna and E. Costa for testing. This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT) [PTDC/AAC-AMB/120940/2010, EXPL/BBB-BIO/1772/2013]; and the FEDER POFC-COMPETE [PEst-C/BIA/UI4050/2011]. FA and GR were supported by FCT fellowships [SFRH/BD/80934/2011 and SFRH/BD/42565/2007, respectively].info:eu-repo/semantics/publishedVersio

    HomozygosityMapper—an interactive approach to homozygosity mapping

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    Homozygosity mapping is a common method for mapping recessive traits in consanguineous families. In most studies, applications for multipoint linkage analyses are applied to determine the genomic region linked to the disease. Unfortunately, these are neither suited for very large families nor for the inclusion of tens of thousands of SNPs. Even if less than 10 000 markers are employed, such an analysis may easily last hours if not days. Here we present a web-based approach to homozygosity mapping. Our application stores marker data in a database into which users can directly upload their own SNP genotype files. Within a few minutes, the database analyses the data, detects homozygous stretches and provides an intuitive graphical interface to the results. The homozygosity in affected individuals is visualized genome-wide with the ability to zoom into single chromosomes and user-defined chromosomal regions. The software also displays the underlying genotypes in all samples. It is integrated with our candidate gene search engine, GeneDistiller, so that users can interactively determine the most promising gene. They can at any point restrict access to their data or make it public, allowing HomozygosityMapper to be used as a data repository for homozygosity-mapping studies. HomozygosityMapper is available at http://www.homozygositymapper.org/

    Neutrophils-A key component of ischemia-reperfusion injury

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    Ischemia-reperfusion injury (IRI) is a common occurrence following myocardial infarction, transplantation, stroke, and trauma that can lead to multiple organ failure, which remains the foremost cause of death in critically ill patients. Current therapeutic strategies for IRI are mainly palliative, and there is an urgent requirement for a therapeutic that could prevent or reverse tissue damage caused by IRI. Neutrophils are the primary responders following ischemia and reperfusion and represent important components in the protracted inflammatory response and severity associated with IRI. Experimental studies demonstrate neutrophil infiltration at the site of ischemia and show that inducing neutropenia can protect organs from IRI. In this review, we highlight the mechanisms involved in neutrophil recruitment, activation, and adherence and how this contributes to disease severity in IRI. Inhibiting neutrophil mobilization, tissue recruitment, and ultimately neutrophil-associated activation of local and systemic inflammatory responses may have therapeutic potential in the amelioration of local and remote tissue damage following IRI. Copyrigh

    Characterization of an extracellular lipase and its chaperone from Ralstonia eutropha H16

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    Lipase enzymes catalyze the reversible hydrolysis of triacylglycerol to fatty acids and glycerol at the lipid–water interface. The metabolically versatile Ralstonia eutropha strain H16 is capable of utilizing various molecules containing long carbon chains such as plant oil, organic acids, or Tween as its sole carbon source for growth. Global gene expression analysis revealed an upregulation of two putative lipase genes during growth on trioleate. Through analysis of growth and activity using strains with gene deletions and complementations, the extracellular lipase (encoded by the lipA gene, locus tag H16_A1322) and lipase-specific chaperone (encoded by the lipB gene, locus tag H16_A1323) produced by R. eutropha H16 was identified. Increase in gene dosage of lipA not only resulted in an increase of the extracellular lipase activity, but also reduced the lag phase during growth on palm oil. LipA is a non-specific lipase that can completely hydrolyze triacylglycerol into its corresponding free fatty acids and glycerol. Although LipA is active over a temperature range from 10 °C to 70 °C, it exhibited optimal activity at 50 °C. While R. eutropha H16 prefers a growth pH of 6.8, its extracellular lipase LipA is most active between pH 7 and 8. Cofactors are not required for lipase activity; however, EDTA and EGTA inhibited LipA activity by 83 %. Metal ions Mg[superscript 2+], Ca[superscript 2+], and Mn[superscript 2+] were found to stimulate LipA activity and relieve chelator inhibition. Certain detergents are found to improve solubility of the lipid substrate or increase lipase-lipid aggregation, as a result SDS and Triton X-100 were able to increase lipase activity by 20 % to 500 %. R. eutropha extracellular LipA activity can be hyper-increased, making the overexpression strain a potential candidate for commercial lipase production or in fermentations using plant oils as the sole carbon source.Malaysia-MIT Biotechnology Partnership Programm
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