The distribution and degradation of radiolabeled superparamagnetic iron oxide nanoparticles and quantum dots in mice

No(51)Cr-labeled, superparamagnetic, iron oxide nanoparticles ((51)Cr-SPIOs) and (65)Zn-labeled CdSe/CdS/ZnS-quantum dots ((65)Zn-Qdots) were prepared using an easy, on demand, exchange-labeling technique and their particokinetic parameters were studied in mice after intravenous injection. The results indicate that the application of these heterologous isotopes can be used to successfully mark the nanoparticles during initial distribution and organ uptake, although the (65)Zn-label appeared not to be fully stable. As the degradation of the nanoparticles takes place, the individual transport mechanisms for the different isotopes must be carefully taken into account. Although this variation in transport paths can bring new insights with regard to the respective trace element homeostasis, it can also limit the relevance of such trace material-based approaches in nanobioscience. By monitoring (51)Cr-SPIOs after oral gavage, the gastrointestinal non-absorption of intact SPIOs in a hydrophilic or lipophilic surrounding was measured in mice with such high sensitivity for the first time. After intravenous injection, polymer-coated, (65)Zn-Qdots were mainly taken up by the liver and spleen, which was different from that of ionic (65)ZnCl2. Following the label for 4 weeks, an indication of substantial degradation of the nanoparticles and the release of the label into the Zn pool was observed. Confocal microscopy of rat liver cryosections (prepared 2 h after intravenous injection of polymer-coated Qdots) revealed a colocalization with markers for Kupffer cells and liver sinusoidal endothelial cells (LSEC), but not with hepatocytes. In J774 macrophages, fluorescent Qdots were found colocalized with lysosomal markers. After 24 h, no signs of degradation could be detected. However, after 12 weeks, no fluorescent nanoparticles could be detected in the liver cryosections, which would confirm our (65)Zn data showing a substantial degradation of the polymer-coated CdSe/CdS/ZnS-Qdots in the liver

Cybersecurity Research Considerations for Heavy Vehicles

The intent of this research is to investigate cybersecurity aspects of medium-duty/heavy-duty (MD/HD) trucks (classes 1 to 8) and compare those aspects to passenger vehicles. Information collected had a significant bias towards HD vehicles (class 7/8), as opposed to MD vehicles. This was due to the discovery process yielding very limited data on MD vehicles (class 3 to 6). This directly correlates to the types of responses provided by industry experts and their cybersecurity concerns (mainly by heavy truck OEMs and suppliers). Much focus was centered around their higher electronic content products that typically occur on class 7/8 vehicle platforms. Often, stakeholder feedback indicated that MD trucks have similar vulnerabilities to either light-duty or heavy-duty trucks but not necessarily anything particularly unique to that segment. This generality likely originates from the similarities between MD truck architectures/designs and HD truck architectures. The objective is to develop a framework to understand common features and differences between passenger vehicle and heavy-duty vehicle cybersecurity in terms of lifecycle, threats and risks, electrical/electronic architectures, control applications, security countermeasures, and industry aspects. Considering recent public awareness of passenger vehicle cybersecurity vulnerabilities, NHTSA undertook this research to understand potential impacts in the heavy-truck vehicle domain. This task started with the investigation of heavy-vehicle cybersecurity practices by contrasting the passenger vehicle cybersecurity knowledge-base to that of heavy vehicles. The project next considered risks in a more generic manner, and identified possible mitigation mechanisms. The comparison framework developed in this document was leveraged to help indemnify the possible mitigation mechanisms. The investigation and data gathering concentrated efforts on issues that affect vehicle safety, but not necessarily asset protection.National Highway Traffic Safety Administrationhttps://deepblue.lib.umich.edu/bitstream/2027.42/151379/1/UMTRI-2018-10.pdfDescription of UMTRI-2018-10.pdf : Technical Repor

An Assessment Method for Automotive Intrusion Detection System Performance

In response to the increased attack surfaces on modern vehicles due to expanded use of software and the introduction of wireless interfaces, a new market has emerged for intrusion detection systems (IDSs), which can detect some types of attacks and are under development by several companies. NHTSA requested development and demonstration of a method for assessing the in-vehicle performance of anomaly-based IDSs for vehicle data buses, specifically buses using controller area network protocols. IDSs may (1) protect vehicles from direct malicious manipulation of the data bus traffic, or (2) detect symptoms of unfriendly modification of firmware on one of the dozens of electronic control units (ECUs) on a modern vehicle’s network. The methodology used provides a means to assess the performance of automotive IDS products, to provide quantitative and qualitative analysis of performance, and to offer insights on potential IDS options.National Highway Traffic Safety Administrationhttps://deepblue.lib.umich.edu/bitstream/2027.42/151378/1/UMTRI-2017-11.pdfDescription of UMTRI-2017-11.pdf : Technical Repor

Synthesis of radioactively labelled CdSe/CdS/ZnS quantum dots for in vivo experiments

NoDuring the last decades of nanoparticles research, many nanomaterials have been developed for applications in the field of bio-labelling. For the visualization of transport processes in the body, organs and cells, luminescent quantum dots (QDs) make for highly useful diagnostic tools. However, intercellular routes, bio-distribution, metabolism during degradation or quantification of the excretion of nanoparticles, and the study of the biological response to the QDs themselves are areas which to date have not been fully investigated. In order to aid in addressing those issues, CdSe/CdS/ZnS QDs were radioactively labelled, which allows quantification of the QD concentration in the whole body or in ex vivo samples by gamma-counting. However, the synthesis of radioactively labelled QDs is not trivial since the coating process must be completely adapted, and material availability, security and avoidance of radioactive waste must be considered. In this contribution, the coating of CdSe/CdS QDs with a radioactive (65)ZnS shell using a modified, operator-safe, SILAR procedure is presented. Under UV illumination, no difference in the photoluminescence of the radioactive and non-radioactive CdSe/CdS/ZnS colloidal solutions was observed. Furthermore, a down-scaled synthesis for the production of very small batches of 5 nmol QDs without loss in the fluorescence quality was developed. Subsequently, the radio-labelled QDs were phase transferred by encapsulation into an amphiphilic polymer. gamma-counting of the radioactivity provided confirmation of the successful labelling and phase transfer of the QDs

ACOs Holding Commercial Contracts Are Larger And More Efficient Than Noncommercial ACOs

Accountable care organizations (ACOs) have diverse contracting arrangements and have displayed wide variation in their performance. Using data from national surveys of 399 ACOs, we examined differences between the 228 commercial ACOs (those with commercial payer contracts) and the 171 noncommercial ACOs (those with only public contracts, such as with Medicare or Medicaid). Commercial ACOs were significantly larger and more integrated with hospitals, and had lower benchmark expenditures and higher quality scores, compared to noncommercial ACOs. Among all of the ACOs, there was low uptake of quality and efficiency activities. However, commercial ACOs reported more use of disease monitoring tools, patient satisfaction data, and quality improvement methods than did noncommercial ACOs. Few ACOs reported having high-level performance monitoring capabilities. About two-thirds of the ACOs had established processes for distributing any savings accrued, and these ACOs allocated approximately the same amount of savings to the ACOs themselves, participating member organizations, and physicians. Our findings demonstrate that ACO delivery systems remain at a nascent stage. Structural differences between commercial and noncommercial ACOs are important factors to consider as public policy efforts continue to evolve

ACOs Holding Commercial Contracts Are Larger And More Efficient Than Noncommercial ACOs

Accountable care organizations (ACOs) have diverse contracting arrangements and have displayed wide variations in their performance. Using data from national surveys of 399 ACOs, we examined differences between the 228 commercial ACOs (those with commercial payer contracts) and the 171 noncommercial ACOs (those with only public contracts, such as with Medicare or Medicaid). Commercial ACOs were significantly larger and more integrated with hospitals, and had lower benchmark expenditures and higher quality scores, compared to noncommercial ACOs. Among all of the ACOs, there was low uptake of quality and efficiency activities. However, commercial ACOs reported more use of disease monitoring tools, patient satisfaction data, and quality improvement methods than did noncommercial ACOs. Few ACOs reported having high-level performance monitoring capabilities. About two-thirds of the ACOs had established processes for distributing any savings accrued, and these ACOs allocated approximately the same amount of savings to the ACOs themselves, participating member organizations, and physicians. Our findings demonstrate that ACO delivery systems remain at a nascent stage. Structural differences between commercial and noncommercial ACOs are important factors to consider as public policy efforts continue to evolve

Phytoplankton distribution patterns in the northwestern Sargasso Sea revealed by small subunit rRNA genes from plastids

Phytoplankton species vary in their physiological properties, and are expected to respond differently to seasonal changes in water column conditions. To assess these varying distribution patterns, we used 412 samples collected monthly over 12 years (1991-2004) at the Bermuda Atlantic Time-Series Study site, located in the northwestern Sargasso Sea. We measured plastid 16S ribosomal RNA gene abundances with a terminal restriction fragment length polymorphism approach and identified distribution patterns for members of the Prymnesiophyceae, Pelagophyceae, Chrysophyceae, Cryptophyceae, Bacillariophyceae and Prasinophyceae. The analysis revealed dynamic bloom patterns by these phytoplankton taxa that begin early in the year, when the mixed layer is deep. Previously, unreported open-ocean prasinophyte blooms dominated the plastid gene signal during convective mixing events. Quantitative PCR confirmed the blooms and transitions of Bathycoccus, Micromonas and Ostreococcus populations. In contrast, taxa belonging to the pelagophytes and chrysophytes, as well as cryptophytes, reached annual peaks during mixed layer shoaling, while Bacillariophyceae (diatoms) were observed only episodically in the 12-year record. Prymnesiophytes dominated the integrated plastid gene signal. They were abundant throughout the water column before mixing events, but persisted in the deep chlorophyll maximum during stratified conditions. Various models have been used to describe mechanisms that drive vernal phytoplankton blooms in temperate seas. The range of taxon-specific bloom patterns observed here indicates that different spring bloom models can aptly describe the behavior of different phytoplankton taxa at a single geographical location. These findings provide insight into the subdivision of niche space by phytoplankton and may lead to improved predictions of phytoplankton responses to changes in ocean conditions. © 2012 International Society for Microbial Ecology All rights reserved