Pre-release Version Research Articles

Evaluation of the ARK Diagnostics immunoassay for qualitative detection of xylazine in urine.

Xylazine exposure is common in some US cities, but a commercial assay for routine laboratory testing for xylazine is not currently available. We evaluated a pre-release version of the ARK Diagnostics immunoassay for qualitative detection of xylazine/4-hydroxyxylazine in urine. Studies were conducted using either the semi-quantitative assay application (A. Roche Cobas 503 analyzer) or the qualitative assay application (B. Beckman Coulter AU480 analyzer). Study specimens consisted of deidentified patient urine samples submitted for routine drugs-of-abuse testing. Measurements of xylazine (X) were performed by LC-MS-MS to obtain X-NEGATIVE (X <10 ng/mL) and X-POSITIVE (X ≥10 ng/mL). The semi-quantitative ARK assay was calibrated with a 10 ng/mL cutoff for ARK-POSITVE. For (A): among 74 X-POSITIVE samples, there was 1 ARK-NEGATIVE result (false-negative rate = 1.4%); among 78 X-NEGATIVE samples by LC-MS-MS, there were 0% ARK-POSITIVE results (false-positive rate = 0%). For (B), among 74 X-POSITIVE samples, there were 0 ARK-NEGATIVE results (false-negative rate = 0%); among 78 X-NEGATIVE samples there was 1 ARK-POSITIVE sample (false-positive rate = 1.3%). Common sources of interferences were investigated without evidence of interference. The ARK xylazine/4-OH-xylazine immunoassay was found to be suitable for routine use in screening patient urine samples for presence of xylazine >10 ng/mL.

Thread/State correspondence: from bit threads to qubit threads

Starting from an interesting coincidence between the bit threads and SS (surface/state) correspondence, both of which are closely related to the holographic RT formula, we introduce a property of bit threads that has not been explicitly proposed before, which can be referred to as thread/state correspondence (see [50] for a brief pre-release version). Using this thread/state correspondence, we can construct the explicit expressions for the SS states corresponding to a set of bulk extremal surfaces in the SS correspondence, and nicely characterize their entanglement structure. Based on this understanding, we use the locking bit thread configurations to construct a holographic qubit threads model as a new toy model of the holographic principle, and show that it is closely related to the holographic tensor networks, the kinematic space, and the connectivity of spacetime.

Finding CYP2D6 activity biomarkers by correlating MDMA pharmacokinetic parameters to untargeted metabolomics data

Cytochrome P450 (CYP) enzymes play a major role in drug metabolism. Many of these enzymes exhibit a huge inter-individual variation in activity, not only attributable to the individual's genotype. Such environmental influences are hardly measurable, let alone their outcome predictable. The actual phenotype is usually determined through administration of well-studied CYP probe substrates – an approach that is obviously unsuitable for forensic investigations, particularly postmortem. Therefore, we aimed at finding alternative biomarkers of the CYP phenotype. Application of metabolomics techniques in theory should reveal endogenous metabolites processed by CYP isoenzymes, which in turn could be indicative for a person's phenotype for particular CYP isoenzymes (e.g. 2D6). In a standard metabolomics approach, features (unidentified metabolites) could be compared between different known CYP genotype/phenotypes. While this approach is most promising, a controlled study needs to be conducted including genotyping and probe-substrate phenotyping. Instead of a new phenotyping study, we aimed to explore the intended approach with a previous crossover study with a typical CYP2D6 substrate (MDMA) and a known inhibitor of CYP2D6 (bupropion) for the general suitability to find endogenous correlates of CYP2D6 activity. Plasma samples of a controlled MDMA/bupropion crossover study with four experimental test sessions (pretreatment – study day as follows: placebo-placebo, bupropion – placebo, placebo-MDMA, and bupropion-MDMA, n = 16 each), initially intended to study pharmacological questions, were reused. Plasma from timepoint 9 from the placebo-placebo and bupropion-placebo session were worked-up by simple protein precipitation and measured with a previously published untargeted metabolomics method (Boxler. Drug Test Anal 2019;11(5):678–696). Briefly, LC-qTOF-MS (Sciex 6600) with reversed-phase (RP) and HILIC chromatography was used in both positive and negative ESI mode. Untargeted data was analysed using msDial 4.8 and a pre-release version of SIRIUS (5.4.1) for structure elucidation and comparison to common databases. Feature peak areas were correlated (spearman) with the ratio of the area under the curve (AUC) of MDMA metabolites/AUC MDMA as determined as the best CYP2D6 correlate in a former targeted analysis (Steuer. Plos One 2016;11:e0150955). Further filter criteria were: fold change between groups of > 2 or < 0.5 and mean S/N > 150. Out of 24858 features found in RP positive mode, by correlation analysis, 27 features with a spearman correlation greater than 0.55 and with assigned MS/MS and 109 features without MS/MS information were found, respectively. As expected, 3 of the features could be unambiguously identified to be bupropion and its known metabolites. Further 10 features indicated a chlorine cluster, not expected endogenously, which pointed to further fragments/metabolites or artifacts of bupropion. The remaining 14 features could be considered as promising biomarker candidates not related to bupropion and as such as tentative indicators of the respective CYP2D6 phenotype. Using the pharmacokinetic parameters of MDMA, acting as a CYP2D6 substrate, with and without CYP2D6 inhibition by bupropion and corresponding metabolomics data, we could show, that the metabolome approach is able to find potential biomarkers for actual CYP2D6 status. As unfortunately typical for untargeted metabolomics, final identification of features still remains the bottleneck and requires further investigation. In addition, the applicability of the found biomarkers of course needs to be tested in a larger independent cohort. Ideally, a ratio of features that are substrate and product of the enzyme could be formed to increase the predictive power of this approach.

Inverse planning in Gamma Knife radiosurgery: A comparative planning study.

To determine the advantages of inverse planning using a prerelease version of Leksell Gamma Knife® (LGK) Lightning (Elekta AB, Sweden) compared to manual forward planning. Thirty-eight patients with metastases (MET, n=15), vestibular schwannomas (VS, n=11) and meningiomas (MEN, n=12), treated with LGK Icon™ at our institution, were analyzed retrospectively. For each case, an inverse (inv) and inverse full coverage (fc) treatment plan was generated using LGK Lightning and compared to the clinical plans. Several dosimetry and efficiency characteristics were compared for each indication. The mean, median difference and interquartile range were reported and the significance was assessed with a paired-sample Wilcoxon test (significance level<0.05). Further, the inter operator variability was analyzed for multiple users. Inv and fc treatment plans show improved target coverage (up to 3.6%) for all analyzed paradigms. For inv plans, the selectivity is enhanced (MET: 2.9%; VS: 1.8%; MEN: 1%) and the organ at risk doses are significantly reduced (VS: up to 4.5%; MEN: up to 17.5%). For inv and fc plans, the beam on time (BOT) is shortened (MET: up to 7.9%; benign tumors: 49.5%). The inter operator variability analysis shows similar treatment plan quality with small differences in plan efficiency (difference in BOT: 1-3.3min). LGK Lightning allows to generate improved LGK treatment plans regarding plan quality with reduced BOT compared to manual forward plans. The inter operator variability showed that multiple users with different experiences can generate similar treatment plan quality using LGK Lightning.

Hands on: Stereo vision building a depth-sensing camera with beta hardware

Getting access to prerelease versions of a platform that you know is going to sell by the million is a great opportunity to get a jump on developing a new open-source product. But it's no guarantee of success: As the team responsible for StereoPi, we soon discovered in building a new version of our stereoscopic vision systems that preliminary hardware can introduce its own quirks into the development process.

INTEGRATING CA4PRS V.3 ROAD WIDENING SCHEDULE MODULE INTO US HIGHWAY EARLY CONSTRUCTABILITY PROCESS: CALIFORNIA SR-91 CORRIDOR IMPROVEMENT PROGRAM CASE STUDY

Performing Constructability Review Processes (CRPs) during the highway design development has been found to save transportation agencies twice their input costs. However, existing literature has identified three areas of CRP improvement: reduction of required agency resources, incorporation of Road User Cost (RUC) scheduling constraints, and integration of assessment visualizations. The authors propose to fill this gap by integrating the Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) v.3 software into the CRP. This module provides agencies with road widening project schedule capabilities, which enhances CRPs by providing accurate RUC-constrained critical path schedules using minimal resources. The module was developed through interviews with subject matter experts from six public and two private California transportation organizations. Said experts also tested the CA4PRS v.3 alpha and beta pre-release versions using data collected from eight Caltrans road widening projects. The potential value-adding of integrating the CA4PRS v.3 software with existing CRPs has been tested through its application on the California State Road 91 (SR-91) Corridor Improvement Program (CIP), resulting in 24-months of construction acceleration. The findings and presentation of the schedule model within this paper provide practitioners an accurate and resource-efficient tool to estimate the schedule impacts of road widening constructability options.

Open Systems Pharmacology Community-An Open Access, Open Source, Open Science Approach to Modeling and Simulation in Pharmaceutical Sciences.

Systems pharmacology integrates structural biological and pharmacological knowledge and experimental data, enabling dissection of organism and drug properties and providing excellent predictivity. ...

An empirical study of DLL injection bugs in the Firefox ecosystem

DLL injection is a technique used for executing code within the address space of another process by forcing the load of a dynamic-link library. In a software ecosystem, the interactions between the host and third-party software increase the maintenance challenges of the system and may lead to bugs. In this work, we empirically investigate bugs that were caused by third-party DLL injections into the Mozilla Firefox browser. Among the 103 studied DLL injection bugs, we found that 93 bugs (90.3%) led to crashes and 57 bugs (55.3%) were caused by antivirus software. Through a survey with third-party software vendors, we observed that some vendors did not perform any QA with pre-release versions nor intend to use a public API (WebExtensions) but insist on using DLL injection. To reduce DLL injection bugs, host software vendors may strengthen the collaboration with third-party vendors, e.g., build a publicly accessible validation test framework. Host software vendors may also use a whitelist approach to only allow vetted DLLs to inject.

Identifying verb collocational patterns in a specialized medical journal corpus

AbstractThis paper examines the collocational patterns of frequent verbs in medical research articles, and proposes a way to help non-native speakers of English learn word combinations frequently used in specific professional genres. We explore the correlations in the syntactico-semantic behavior and the collocational patterns of related verbs, in order to systematically teach recurrent word combinations.To this end, we present a corpus-based analysis of the collocational patterning of the verbs which belong to the same semantic frame inFrameNet, the frame EVIDENCE. These verbs were identified in 397 medical research articles from a pre-release version of the PERC (Professional English Research Consortium) corpus (3,155,118 tokens and 115,960 word types). The verbs examined, in approximate order of degree of increasing certainty, aresuggest, argue, show, reveal, prove, demonstrate, substantiate, verify, confirmandcorroborate. The results reveal that verbs that can be grouped into semantic and syntactic coherent sets also share combinatorial properties. We conclude that, rather than studying isolated verbs, making learners aware of these patterns of verb groups can greatly contribute toward efficient learning of the language of professional texts.

High-precision Orbit Fitting and Uncertainty Analysis of (486958) 2014 MU69

Abstract NASA’s New Horizons spacecraft will conduct a close flyby of the cold-classical Kuiper Belt Object (KBO) designated (486958) 2014 MU69 on 2019 January 1. At a heliocentric distance of 44 au, “MU69” will be the most distant object ever visited by a spacecraft. To enable this flyby, we have developed an extremely high-precision orbit fitting and uncertainty processing pipeline, making maximal use of the Hubble Space Telescope’s Wide Field Camera 3 (WFC3) and pre-release versions of the ESA Gaia Data Release 2 (DR2) catalog. This pipeline also enabled successful predictions of a stellar occultation by MU69 in 2017 July. We describe how we process the WFC3 images to match the Gaia DR2 catalog, extract positional uncertainties for this extremely faint target (typically 140 photons per WFC3 exposure), and translate those uncertainties into probability distribution functions for MU69 at any given time. We also describe how we use these uncertainties to guide New Horizons, plan stellar occultions of MU69, and derive MU69's orbital evolution and long-term stability.

Skilful Seasonal Predictions of Summer European Rainfall

AbstractYear‐to‐year variability in Northern European summer rainfall has profound societal and economic impacts; however, current seasonal forecast systems show no significant forecast skill. Here we show that skillful predictions are possible (r ~0.5, p &lt; 0.001) using the latest high‐resolution Met Office near‐term prediction system over 1960–2017. The model predictions capture both low‐frequency changes (e.g., wet summers 2007–2012) and some of the large individual events (e.g., dry summer 1976). Skill is linked to predictable North Atlantic sea surface temperature variability changing the supply of water vapor into Northern Europe and so modulating convective rainfall. However, dynamical circulation variability is not well predicted in general—although some interannual skill is found. Due to the weak amplitude of the forced model signal (likely caused by missing or weak model responses), very large ensembles (&gt;80 members) are required for skillful predictions. This work is promising for the development of European summer rainfall climate services.

Modeling of initially curved and twisted smart beams using intrinsic equations

The work presented in this paper provides a reliable method to model and analyze smart beams with arbitrary sectional geometries and material properties, including initially curved and twisted beams. It incorporates the modified constitutive equations into the intrinsic equations to formulate a generalized set of solutions applicable for both the actuator and sensor application of piezoelectric smart beams. The radial field problem, sometimes referred to as radially electroded problem, where the potential is applied on the surfaces along the length (i.e., along the reference line) of the smart beam, is considered in the present study. Three different cases of smart beam geometries are discussed to highlight the capabilities of this method. VABS 4.0, a prerelease version of the variational asymptotic cross-sectional analysis tool for composite beams, is used to obtain the intermediate results containing sectional properties, which are used as inputs into the modified intrinsic equations. The main advantage of this method is its ability to quickly and accurately analyze deformation in smart beams. The values of displacements and rotations obtained along the length can be further used to recover the unknown 3D displacements, stresses and electric potentials using recovery relations. Successful verification of results obtained from the linear equations is presented and is accomplished using a commercially available finite element code ABAQUS.

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OBJECTIVES/SPECIFIC AIMS: The iobio project enables anyone (eg, diagnosticians, MDs, genetic counselors, citizen scientists) to perform useful analysis of genomic data, without a need to rely on bioinformaticians. iobio uses a novel real-time analysis framework, coupled with powerful visualizations delivered in a standard web browser. The project successfully supports free academic/nonprofit users, but occasions exist where it is more applicable for the project to be delivered commercially. Frameshift Genomics is developing commercial applications and functionality, which will exist alongside and in coordination with the academic project. These products will be marketed to large institutions including genome institutes, hospitals, diagnostic labs etc., but also to individual users who do not have access to large compute resources, or bioinformatic analysts, and everything in between. METHODS/STUDY POPULATION: The commercial iobio project under Frameshift Genomics aims to develop applications and features that cannot be successfully supported by an academic model. For example, when analyses are scaled up to processing of extremely large data sets, a commercial product with access to compute resources makes more sense than an academic tool. Bam.iobio is an application that samples data from sequencing alignment files, taking seconds to generate and visualize statistics representative of the entire file. This app is offered for free academically. When analysis involves thousands of such files, however, the commercial application, multibam.iobio, is more suitable. Other examples, including support for licensed third-party software and permitting extensive computation via cloud platforms, can also only be reasonably be supported via commercial software. Finally, development of commercial applications is driving adoption of more rigorous testing platforms, delivering more robust products. A particular strength of the iobio platform is allowing non-bioinformaticians to understand their data, for example providing quality control functionality providing confidence in data sets and the conclusions drawn from them. Such analyses are critical to all users of genomic data, and the iobio platform is ideally suited to provide an intuitive, integrated framework for performing them. RESULTS/ANTICIPATED RESULTS: The iobio project has been readily adopted by many in the community and shows significant promise for democratizing genomic analysis. Work is ongoing, supported by NIH small business grants, to develop commercial applications that will be marketed to analysts and medical professionals from large genome institutes and universities, to individual project users and citizen scientists. DISCUSSION/SIGNIFICANCE OF IMPACT: There are currently a number of iobio tools available academically, and they have been embraced by many in the genomics community. In fact, a number of popular platforms (eg, Galaxy, the International Cancer Genome Consortium (ICGC) data portal, mygene2 at the University of Washington) have incorporated iobio tools into their own platforms. To date, the gene.iobio variant interrogation tool has been used in a number of diagnostic projects, aiding identification of putative causative variants, and the pre-release version of the commercial multibam.iobio tool has been critical in unearthing data quality problems in project level data.

Oncopression: gene expression compendium for cancer with matched normal tissues

Expression profile of normal tissue is primary source to find genes showing aberrant expression pattern specific in matched cancer tissue, but sample number of normal control in public gene expression repositories is disproportionally small compared to cancer and scattered in several datasets. We built oncopression by integrating several datasets into one large dataset for comprehensive analysis about 25 types of human cancers including 20 640 cancer samples and 6801 normal control profiles. Expression profiles in cancers can be directly compared to normal tissue counterparts. Validity of the integration was tested using immunohistochemical staining results and principal component analysis. We have utilized the pre-release version of oncopression to identify cancer-specific genes in several studies. Free access at http://www.oncopression.com and all expression data are available for download at the site. cchoi@kaist.ac.kr or jungsullee@gmail.com. Supplementary data are available at Bioinformatics online.

CAR-T Cell Production Using the Clinimacs® Prodigy System

IntroductionChimeric Antigen Receptor T (CAR-T) cells redirected against tumor antigens are an effective therapy for B cell malignancies refractory to standard treatments. The production of patient-derived CAR-T cells is complicated and thus far is limited to institutions with experienced researchers and expensive GMP facilities, or to those invited to participate in industry sponsored clinical trials. The outsourcing of CAR T-cell production to third party vendors where cells are collected locally, shipped to the manufacturing site, and then sent back to the institution for infusion can be both costly and timely. As a result, CAR-T cell therapies are not widely available and only patients with means to travel to participating sites and with disease that is stable enough to wait the 2-3 months needed to collect and produce CAR-T cells are eligible for these treatments.At our instution we have explored the use of the CliniMACS® Prodigy (Miltenyi Biotec, Inc) for the production of CAR-T cells. The CliniMACS® Prodigy is an automated device that can be used for cell processing within a closed GMP-compliant system. Using the CAR-T system that includes software, specialized tubing sets, and optimized reagents we demonstrate the processing of CAR-T cells, with similar characteristics to those produced in a more traditional manner, in a closed system that is suitable for clinical use without the need for a clean room manufacturing facility.MethodsIn collaboration with Miltenyi Biotec, we obtained pre-release and final versions of the CliniMACS® Prodigy TCT process software and the TS520 tubing set that allows for cell enrichment, transduction, wash steps, and expansion all within a single set. Starting material was MNC cells recovered from a leukoreduction system chamber (LRSC) used during platelet collections by apheresis. Materials and reagents included MACS CD4 & CD8 reagents for cell enrichment, TransAct CD3/CD28 reagent for activation, lentiviral CD8 TM-41BB-CD3 zeta-cfrag vectors with either CD19 or CD20/CD19 Ab chains (Lentigen Technology Inc., A Miltenyi Biotec Company), TexMACS culture medium-3% HS-IL2, and PBS/EDTA buffer for wash steps. For two experiments, cells after CD4/CD8 enrichment were activated and transduced in 6 well plates and expanded after day 5 in G-Rex gas permerable devices. Total time for line preparation was 14±1 days. Transduction was measured by Protein L expression using flow cytometry. Line function was measured in 51Cr Release assays and by intracellular cytokine production.ResultsStarting cells were washed free of platelets and enriched for CD4+ and CD8+ cells using the Prodigy device. We achieved consistent high levels purity (99±3%) and good recovery (51.0±6%) of CD4+ and CD8+ cells (N=5). The enriched cells were 90±12% CD3+. The approximately 10% non-T cells were CD8+ NK cells, that were largely eliminated after cell activation through CD3/CD28 and expansion. A controlled number of 1 x 10E8 cells enriched for CD4+ plus CD8+ cells were retained in the Prodigy and in 2 experiments a smaller fraction of cells was cultured in 6 well plates for activation and initial transduction. Three preparations were conducted in the Prodigy, one using the CD19 vector and two with the CD19+CD20 vector. Transduction efficiency ranged from 21%-46% of total T cells with a modest preference for CD4+ cells. Expansion ranged from 26-40 fold and all of the lines recognized CD19 and/or CD20 targets based on 51Cr release assays or IFN-gamma production. The paired lines generated on the Prodigy versus manual methods showed similar overall transduction, phenotype, and function as shown in the figure for one representative preparation.ConclusionsCAR-T cells generated in the Prodigy were similar to those prepared using manual methods in both phenotype and function. This process is timely, requiring 14 days for generation of the target CAR-T cell dose, and does not require outsourcing to third party vendors. All of the Prodigy CAR-T cell preparations met criteria for clinical use in our upcoming Phase I clinical trial. The ability to produce CAR-T cells suitable for clinical use in an entirely closed system without the need for a clean room should allow more centers and patients access to this novel form of immunotherapy. [Display omitted] DisclosuresShah:Oncosec: Equity Ownership; Exelixis: Equity Ownership; Geron: Equity Ownership. Orentas:Lentigen Technology, Inc.: Employment. Dropulic:Lentigen Technology Inc. A Miltenyi Biotec Company: Employment. Hari:Merck: Research Funding; BMS: Honoraria.

Turbulence Resolving Flow Simulations of a Francis Turbine in Part Load using Highly Parallel CFD Simulations

The operation of Francis turbines in part load conditions causes high fluctuations and dynamic loads in the turbine and especially in the draft tube. At the hub of the runner outlet a rotating vortex rope within a low pressure zone arises and propagates into the draft tube cone. The investigated part load operating point is at about 72% discharge of best efficiency. To reduce the possible influence of boundary conditions on the solution, a flow simulation of a complete Francis turbine is conducted consisting of spiral case, stay and guide vanes, runner and draft tube. As the flow has a strong swirling component for the chosen operating point, it is very challenging to accurately predict the flow and in particular the flow losses in the diffusor. The goal of this study is to reach significantly better numerical prediction of this flow type. This is achieved by an improved resolution of small turbulent structures. Therefore, the Scale Adaptive Simulation SAS-SST turbulence model - a scale resolving turbulence model - is applied and compared to the widely used RANS-SST turbulence model. The largest mesh contains 300 million elements, which achieves LES-like resolution throughout much of the computational domain. The simulations are evaluated in terms of the hydraulic losses in the machine, evaluation of the velocity field, pressure oscillations in the draft tube and visual comparisons of turbulent flow structures. A pre-release version of ANSYS CFX 17.0 is used in this paper, as this CFD solver has a parallel performance up to several thousands of cores for this application which includes a transient rotor-stator interface to support the relative motion between the runner and the stationary portions of the water turbine.

Forensic genetics in NGS era: New frontiers for massively parallel typing

Next generation sequencing (NGS) represents the newest approach for massive DNA sequencing. Although this innovative approach is a well-established point in diagnostic genetics, the applicability in forensic field is still limited to sporadic pilot studies. This limit arises from the samples’ complexity, in terms of poor quality/quantity ratio, leading to a difficult setting in analytic systems.In this study, first NGS forensic data with a new analytic protocol are presented; data were obtained with a pre-release version of the MiSeq system (Illumina). The system is able to sequence, at the same time, a wide panel including autosomal 63 STRs and 95 SNPs commonly used in forensic practice.In the first part of the study sensitivity and concordance studies were performed by using DNA controls with known genetic profile; also mixtures with different male/female concentrations were analysed, in order to verify the panel performance in comparison with traditional kits. In the second part of the experiment, 60 casework samples coming from different tissues, biological fluids, traces on supports, lysates, different aged/degraded samples were analysed. Bioinformatic analysis was performed with MiSeq FGx System BETA version (Illumina), an innovative software with an easy interface that permits a rapid data interpretation by filtering the big data quantity generated by the instrument.The comparison between new data and genetic profiles obtained with traditional typing on the same samples, the sensitivity and the potential of NGS approach represents an interesting starting point in introducing this innovative approach on forensic genetics scenario.

Estimates of non-traditional secondary organic aerosols from aircraft SVOC and IVOC emissions using CMAQ

Abstract. Utilizing an aircraft-specific parameterization based on smog chamber data in the Community Multiscale Air Quality (CMAQ) model with the volatility basis set (VBS), we estimated contributions of non-traditional secondary organic aerosols (NTSOA) for aircraft emissions during landing and takeoff (LTO) activities at the Hartsfield–Jackson Atlanta International Airport. NTSOA, formed from the oxidation of semi-volatile and intermediate volatility organic compounds (S/IVOCs), is a heretofore unaccounted component of fine particulate matter (PM2.5) in most air quality models. We expanded a prerelease version of CMAQ with VBS implemented for the Carbon Bond 2005 (CB05) chemical mechanism to use the Statewide Air Pollution Research Center 2007 (SAPRC-07) chemical mechanism and added species representing aircraft S/IVOCs and corresponding NTSOA oxidation products. Results indicated that the maximum monthly average NTSOA contributions occurred at the airport and ranged from 2.4 ng m−3 (34 % from idle and 66 % from non-idle aircraft activities) in January to 9.1 ng m−3 (33 and 67 %) in July. This represents 1.7 % (of 140 ng m−3) in January and 7.4 % in July (of 122 ng m−3) of aircraft-attributable PM2.5 compared to 41.0–42.0 % from elemental carbon and 42.8–58.0 % from inorganic aerosols. As a percentage of PM2.5, impacts were higher downwind of the airport, where NTSOA averaged 4.6–17.9 % of aircraft-attributable PM2.5 and, considering alternative aging schemes, was as high as 24.0 % – thus indicating the increased contribution of aircraft-attributable SOA as a component of PM2.5. However, NTSOA contributions were generally low compared to smog chamber results, particularly at idle, due to the considerably lower ambient organic aerosol concentrations in CMAQ compared to those in the smog chamber experiments.

Comparison of a novel free breathing SSFP sequence with standard breath held SSFP- a pilot study

Background Despite advances in magnetic resonance imaging hardware and software, the acquisition of optimal cardiac magnetic resonance (CMR) images may be hampered by several factors. Most notably, scan length, the requirement for multiple breath holds and cardiac gating can all impact upon image quality. Real time cardiac imaging holds promise for reducing scan times via rapid acquisitions of images that are not reliant on breath holding or cardiac gating. Recently, a novel free breathing SSFP sequence was made available as part of a pre-release version of the HeartVista Cardiac Package, Version 1.0.0 (HeartVista, Inc.). Our goal was to compare the assessment of LV function between the HeartVista free breathing SSFP (FB-SSFP) sequence and standard FIESTA breath held SSFP.

Evaluation of a new six degrees of freedom couch for radiation therapy

The aim of this work is to evaluate the geometric accuracy of a prerelease version of a new six degrees of freedom (6DoF) couch. Additionally, a quality assurance method for 6DoF couches is proposed. The main principle of the performance tests was to request a known shift for the 6DoF couch and to compare this requested shift with the actually applied shift by independently measuring the applied shift using different methods (graph paper, laser, inclinometer, and imaging system). The performance of each of the six axes was tested separately as well as in combination with the other axes. Functional cases as well as realistic clinical cases were analyzed. The tests were performed without a couch load and with a couch load of up to 200 kg and shifts in the range between -4 and +4 cm for the translational axes and between -3° and +3° for the rotational axes were applied. The quality assurance method of the new 6DoF couch was performed using a simple cube phantom and the imaging system. The deviations (mean ± one standard deviation) accumulated over all performance tests between the requested shifts and the measurements of the applied shifts were -0.01 ± 0.02, 0.01 ± 0.02, and 0.01 ± 0.02 cm for the longitudinal, lateral, and vertical axes, respectively. The corresponding values for the three rotational axes couch rotation, pitch, and roll were 0.03° ± 0.06°, -0.04° ± 0.12°, and -0.01° ± 0.08°, respectively. There was no difference found between the tests with and without a couch load of up to 200 kg. The new 6DoF couch is able to apply requested shifts with high accuracy. It has the potential to be used for treatment techniques with the highest demands in patient setup accuracy such as those needed in stereotactic treatments. Shifts can be applied efficiently and automatically. Daily quality assurance of the 6DoF couch can be performed in an easy and efficient way. Long-term stability has to be evaluated in further tests.