0000000000753565
AUTHOR
J. Schneider
The impact of mineral dust on cloud formation during the Saharan dust event in April 2014 over Europe
A regional modeling study on the impact of desert dust on cloud formation is presented for a major Saharan dust outbreak over Europe from 2 to 5 April 2014. The dust event coincided with an extensive and dense cirrus cloud layer, suggesting an influence of dust on atmospheric ice nucleation. Using interactive simulation with the regional dust model COSMO-MUSCAT, we investigate cloud and precipitation representation in the model and test the sensitivity of cloud parameters to dust–cloud and dust–radiation interactions of the simulated dust plume. We evaluate model results with ground-based and spaceborne remote sensing measurements of aerosol and cloud properties, as well as the in situ meas…
Aerosol properties, source identification, and cloud processing in orographic clouds measured by single particle mass spectrometry on a central European mountain site during HCCT-2010
Cloud residues and out-of-cloud aerosol particles with diameters between 150 and 900 nm were analysed by online single particle aerosol mass spectrometry during the 6-week study Hill Cap Cloud Thuringia (HCCT)-2010 in September–October 2010. The measurement location was the mountain Schmücke (937 m a.s.l.) in central Germany. More than 160 000 bipolar mass spectra from out-of-cloud aerosol particles and more than 13 000 bipolar mass spectra from cloud residual particles were obtained and were classified using a fuzzy c-means clustering algorithm. Analysis of the uncertainty of the sorting algorithm was conducted on a subset of the data by comparing the clustering output with particle-by-par…
A Search for IceCube Events in the Direction of ANITA Neutrino Candidates
During the first three flights of the Antarctic Impulsive Transient Antenna (ANITA) experiment, the collaboration detected several neutrino candidates. Two of these candidate events were consistent with an ultra-high-energy up-going air shower and compatible with a tau neutrino interpretation. A third neutrino candidate event was detected in a search for Askaryan radiation in the Antarctic ice, although it is also consistent with the background expectation. The inferred emergence angle of the first two events is in tension with IceCube and ANITA limits on isotropic cosmogenic neutrino fluxes. Here, we test the hypothesis that these events are astrophysical in origin, possibly caused by a po…
Radiation exposure in vascular angiographic procedures.
Abstract Purpose To evaluate dose reduction in vascular angiographic procedures by using fluoroscopy capture instead of digital subtraction angiography frames for documentation. Materials and Methods A total of 764 consecutive vascular interventional procedures performed over a period of 1 year were retrospectively analyzed with respect to the fluoroscopy time and the resulting dose–area product (DAP), the DAP of the radiographic frames, and the overall DAP. Results A total of 70% of the total DAP was a result of the acquisition of radiographic frames, leaving only 30% being applied by fluoroscopy. Conclusions Fluoroscopy capture should be used for documentation whenever possible. A registr…
IceCube search for neutrinos coincident with compact binary mergers from LIGO-Virgo's first gravitational-wave transient catalog
Using the IceCube Neutrino Observatory, we search for high-energy neutrino emission coincident with compact binary mergers observed by the LIGO and Virgo gravitational-wave (GW) detectors during their first and second observing runs. We present results from two searches targeting emission coincident with the sky localization of each GW event within a 1000 s time window centered around the reported merger time. One search uses a model-independent unbinned maximum-likelihood analysis, which uses neutrino data from IceCube to search for pointlike neutrino sources consistent with the sky localization of GW events. The other uses the Low-Latency Algorithm for Multi-messenger Astrophysics, which …
Comparison of aircraft measurements during GoAmazon2014/5 and ACRIDICON-CHUVA
Abstract. The indirect effect of atmospheric aerosol particles on the Earth's radiation balance remains one of the most uncertain components affecting climate change throughout the industrial period. The large uncertainty is partly due to the incomplete understanding of aerosol–cloud interactions. One objective of the GoAmazon2014/5 and the ACRIDICON (Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems)-CHUVA (Cloud Processes of the Main Precipitation Systems in Brazil) projects was to understand the influence of emissions from the tropical megacity of Manaus (Brazil) on the surrounding atmospheric environment of the rainforest and to investiga…
Transarterielle Chemoembolisation (TACE) des Hepatozellulären Karzinoms (HCC) bei Patienten mit Pfortaderthrombose - Erfahrungen
PURPOSE: Comparative analysis of the course of disease in patients with initial diagnosis of portal vein thrombosis in HCC treated with sequential TACE. Evaluation of the efficacy and safety of the method in a selected patient cohort. PATIENTS AND METHODS: The study included 22 patients with HCC that were palliatively treated at least 3 times with TACE. All patients presented a portal vein thrombosis in the initial CT investigation. The TACE-procedure was carried out in regular intervals using a suspension consisting of a fixed dosage of Mitomycin C (10 mg) and 10-20 ml Lipiodol. Follow-up investigations were carried out with contrast enhanced Multislice-CT before and after TACE and control…
Liver Preservation by Aortic Perfusion Alone Compared With Preservation by Aortic Perfusion and Additional Arterial Ex Situ Back-Table Perfusion With Histidine-Tryptophan-Ketoglutarate Solution: A Prospective, Randomized, Controlled, Multicenter Study.
Background. Arterial ex situ back-table perfusion (BP) reportedly reduces ischemic-type biliary lesion after liver transplantation. We aimed to verify these findings in a prospective investigation. Methods. Our prospective, randomized, controlled, multicenter study involved livers retrieved from patients in 2 German regions, and compared the outcomes of standard aortic perfusion to those of aortic perfusion combined with arterial ex situ BP. The primary endpoint was the incidence of ischemic-type biliary lesions over a follow-up of 2 years after liver transplantation, whereas secondary endpoints included 2-year graft survival, initial graft damage as reflected by transaminase levels, and fu…
Mass-spectrometric identification of primary biological particle markers and application to pristine submicron aerosol measurements in Amazonia
The detection of primary biological material in submicron aerosol by means of thermal desorption/electron impact ionization aerosol mass spectrometry was investigated. Mass spectra of amino acids, carbohydrates, small peptides, and proteins, all of which are key building blocks of biological particles, were recorded in laboratory experiments. Several characteristic marker fragments were identified. The intensity of the marker signals relative to the total organic mass spectrum allows for an estimation of the content of primary biological material in ambient organic aerosol. The developed method was applied to mass spectra recorded during AMAZE-08, a field campaign conducted in the pristine …
Aircraft-based observations of isoprene-epoxydiol-derived secondary organic aerosol (IEPOX-SOA) in the tropical upper troposphere over the Amazon region
During the ACRIDICON-CHUVA field project (September–October 2014; based in Manaus, Brazil) aircraft-based in situ measurements of aerosol chemical composition were conducted in the tropical troposphere over the Amazon using the High Altitude and Long Range Research Aircraft (HALO), covering altitudes from the boundary layer (BL) height up to 14.4 km. The submicron non-refractory aerosol was characterized by flash-vaporization/electron impact-ionization aerosol particle mass spectrometry. The results show that significant secondary organic aerosol (SOA) formation by isoprene oxidation products occurs in the upper troposphere (UT), leading to increased organic aerosol mass concentratio…
Particulate trimethylamine in the summertime Canadian high Arctic lower troposphere
Size-resolved and vertical profile measurements of single particle chemical composition (sampling altitude range 50–3000 m) were conducted in July 2014 in the Canadian high Arctic during an aircraft-based measurement campaign (NETCARE 2014). We deployed the single particle laser ablation aerosol mass spectrometer ALABAMA (vacuum aerodynamic diameter range approximately 200–1000 nm) to identify different particle types and their mixing states. On the basis of the single particle analysis, we found that a significant fraction (23 %) of all analyzed particles (in total: 7412) contained trimethylamine (TMA). Two main pieces of evidence suggest that these TMA-containing particles originated from…
Transarterial Chemoembolization in Patients Not Eligible for Liver Transplantation: Single-Center Results
OBJECTIVE. The purpose of this study was to evaluate the effectiveness of transarterial chemoembolization in the care of patients not eligible for liver transplantation.CONCLUSIONS. Prognosis depends on local response, Okuda score, α-fetoprotein level, and tumor size and is independent of the presence of portal venous thrombosis.
Influence of Collective Surface Motion on the Threshold Behavior of Nuclear Fusion
Fusion excitation functions for the systems $^{40}\mathrm{Ar}$+$^{112,116,122}\mathrm{Sn}$ and $^{40}\mathrm{Ar}$+$^{144,148,154}\mathrm{Sm}$ have been determined, covering cross sections ranging from several hundred millibarns down to the microbarn level. The data are interpreted with a fusion model that includes fluctuations of the barrier with an amplitude that is shown to be correlated with the collective surface properties of the nuclei. There is no need to assume an additional enhanced tunneling process.
Quantitative single-particle analysis with the Aerodyne aerosol mass spectrometer: development of a new classification algorithm and its application to field data
Single-particle mass spectrometry has proven a valuable tool for gaining information on the mixing state of aerosol particles. With the Aerodyne aerosol mass spectrometer (AMS) equipped with a light-scattering probe, non-refractory components of submicron particles with diameters larger than about 300 nm can even be quantified on a single-particle basis. Here, we present a new method for the analysis of AMS single-particle mass spectra. The developed algorithm classifies the particles according to their components (e.g. sulphate, nitrate, different types of organics) and simultaneously provides quantitative information about the composition of the single particles. This classification algor…
Polymeric amphiphiles with hydrophilic main chain spacers: Studies in monolayers and Langmuir-Blodgett multilayers
A methacrylic lipid was polymerized to form an amphiphilic homopolymer and random copolymers with various levels of acrylic acid comonomers. The behavior of these polymeric lipids was investigated in monolayers at the air-water interface and in Langmuir-Blodgett multilayers on polymer foil supports. The acrylic acid acts as a hydrophilic spacer along the polymer backbone, and improves the ability of the polymer to self-organize into highly ordered monolayers and ultimately LB multilayers. It is shown that the quality and stability of the multilayers increase substantially with the increase in comonomer content.
3-NPA induziert Ischämietoleranz der Rattenleber nach warmer Ischämie
Until now little is known about the potential of 3-nitroproprionic acid (3-NPA) to reduce ischemia/ reperfusion injury (IRI) of the rat liver in vivo.
Organ recipients suffering from undifferentiated neuroendocrine small-cell carcinoma of donor origin: a case report.
Abstract Background Transmission of donor-derived cancer by organ transplantation is rare, but the risk has been increasing due to the aging donor pool. Undifferentiated neuroendocrine small-cell carcinoma is an agressive tumor with the tendency to spread. Herein we have demonstrated different approaches to treat organ recipients with transmitted tumors. Methods and Results Grafts were retrieved from a decreased donor without any history of previous diseases. Autopsy was not performed after donation. The recipient of the liver graft presented with suspected nodules on routine abdominal ultrasound. After computed tomography (CT) scan, biopsy confirmed the diagnosis of a small-cell carcinoma.…
Sequentielle transarterielle Chemoembolisation (TACE) des hepatozellulären Karzinoms (HCC) - Erfahrungsbericht eines einzelnen Zentrums über 5 Jahre
PURPOSE: To analyze the course of disease of patients treated with sequential TACE and to evaluate the dependent and independent prognostic factors for patient survival using the Cox Proportional Hazard Model. MATERIALS AND METHODS: 94 patients palliatively treated with TACE. Patients were selected if they had been treated at least 3 times. The TACE procedure was carried out at 8-week intervals using a suspension consisting of a fixed dosage of Mitomycin C (10 mg) and 10 ml Lipiodol. Follow-up investigations included contrast-enhanced multislice CT before and after TACE and assessment of the laboratory test results (i. e., blood count, liver enzymes, and coagulation). RESULTS: In 66.7 % of …
New investigations on homogeneous ice nucleation: the effects of water activity and water saturation formulations
Laboratory measurements at the AIDA cloud chamber and airborne in-situ observations suggest that the homogeneous freezing thresholds at low temperatures are possibly higher than expected from the so-called “Koop-line”. This finding is of importance, because the ice onset relative humidity affects the cirrus cloud coverage and, at the very low temperatures of the tropical tropopause layer, together with the number of ice crystals also the transport of water vapor into the stratosphere. Both, the appearance of cirrus clouds and the amount of stratospheric water feed back to the radiative budget of the atmosphere. In order to explore the enhanced ice onset humidities, we re-examine…
Characteristics of the diffuse astrophysical electron and Tau neutrino flux with six years of IceCube high energy cascade data
We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of φastro=1.66-0.27+0.25 at E0=100 TeV, in agreement with IceCube's complementary muon neutrino results and wit…
Ship emissions measurement in the Arctic by plume intercepts of the Canadian Coast Guard icebreaker Amundsen from the Polar 6 aircraft platform
Decreasing sea ice and increasing marine navigability in northern latitudes have changed Arctic ship traffic patterns in recent years and are predicted to increase annual ship traffic in the Arctic in the future. Development of effective regulations to manage environmental impacts of shipping requires an understanding of ship emissions and atmospheric processing in the Arctic environment. As part of the summer 2014 NETCARE (Network on Climate and Aerosols) campaign, the plume dispersion and gas and particle emission factors of effluents originating from the Canadian Coast Guard icebreaker Amundsen operating near Resolute Bay, NU, Canada, were investigated. The Amundsen burned distillate fue…
African volcanic emissions influencing atmospheric aerosols over the Amazon rain forest
Long-range transport (LRT) plays an important role in the Amazon rain forest by bringing in different primary and secondary aerosol particles from distant sources. The atmospheric oxidation of dimethyl sulfide (DMS), emitted from marine plankton, is considered an important sulfate source over the Amazon rain forest, with a lesser contribution from terrestrial soil and vegetation sulfur emissions. Volcanic sulfur emissions from Africa could be a source of particulate sulfate to the Amazonian atmosphere upon transatlantic transport but no observations have been published. By using satellite observations, together with ground‑based and airborne aerosol particle observations, this paper provide…
Combined sensitivity to the neutrino mass ordering with JUNO, the IceCube Upgrade, and PINGU
Physical review / D 101(3), 032006 (1-19) (2020). doi:10.1103/PhysRevD.101.032006
Growth of nucleation mode particles in the summertime Arctic: a case study
Abstract. The summertime Arctic lower troposphere is a relatively pristine background aerosol environment dominated by nucleation and Aitken mode particles. Understanding the mechanisms that control the formation and growth of aerosol is crucial for our ability to predict cloud properties and therefore radiative balance and climate. We present an analysis of an aerosol growth event observed in the Canadian Arctic Archipelago during summer as part of the NETCARE project. Under stable and clean atmospheric conditions, with low inversion heights, carbon monoxide less than 80 ppbv, and black carbon less than 5 ng m−3, we observe growth of small particles, < 20 nm in diameter, into sizes ab…
Design of a mobile aerosol research laboratory and data processing tools for effective stationary and mobile field measurements
A compact mobile aerosol research laboratory (MoLa) for stationary and mobile measurements of aerosol and trace gas characteristics was developed at the Max Planck Institute for Chemistry (MPIC) in Mainz, Germany. Major efforts were made to design an aerosol inlet system which is optimized and characterised for both, stationary and mobile measurements using a particle loss modelling approach. The instrumentation on board allows the determination of a multitude of physical and chemical aerosol parameters, for example particle number and mass concentration (PM<sub>1/2.5/10</sub>), particle size distributions in the diameter range 6 nm up to 32 μm, and chemical composition of the s…
Noninvasive assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension by high temporal resolution phase-contrast MRI: correlation with simultaneous invasive pressure recordings.
Background— Right heart catheterization is the gold standard for assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension. To date, MRI has not been able to produce precise measurements of mean pulmonary arterial pressure (mPAP). The purpose of the study was to create a model for estimating mPAP and pulmonary vascular resistance in patients with chronic thromboembolic pulmonary hypertension by high temporal resolution phase-contrast MRI (PC-MRI) and to correlate the results with simultaneously acquired, invasive catheter-based measurements (simultaneously measured mPAP) and with right heart catheterization measurements. Methods and Results— A tota…
Quantitative single particle analysis with the Aerodyne aerosol mass spectrometer: development of a new classification algorithm and its application to field data
Abstract. Single particle mass spectrometry has proven a valuable tool for gaining information on the mixing state of aerosol particles. With the Aerodyne aerosol mass spectrometer (AMS) equipped with a light scattering probe, non-refractory components of submicron particles with diameters larger than about 300 nm can even be quantified on a single particle basis. Here, we present a new method for the analysis of AMS single particle mass spectra. The developed algorithm classifies the particles according to their components (e.g., sulphate, nitrate, different types of organics) and simultaneously provides quantitative information about the composition of the single particles. This classific…
Radiation exposure in CT-guided interventions.
To investigate radiation exposure in computed tomography (CT)-guided interventions, to establish reference levels for exposure, and to discuss strategies for dose reduction.We analyzed 1576 consecutive CT-guided procedures in 1284 patients performed over 4.5 years, including drainage placements; biopsies of different organs; radiofrequency and microwave ablations (RFA/MWA) of liver, bone, and lung tumors; pain blockages, and vertebroplasties. Data were analyzed with respect to scanner settings, overall radiation doses, and individual doses of planning CT series, CT intervention, and control CT series.Eighty-five percent of the total radiation dose was applied during the pre- and post-interv…
Aerosol characteristics and particle production in the upper troposphere over the Amazon Basin
Airborne observations over the Amazon Basin showed high aerosol particle concentrations in the upper troposphere (UT) between 8 and 15 km altitude, with number densities (normalized to standard temperature and pressure) often exceeding those in the planetary boundary layer (PBL) by 1 or 2 orders of magnitude. The measurements were made during the German–Brazilian cooperative aircraft campaign ACRIDICON–CHUVA, where ACRIDICON stands for Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems and CHUVA is the acronym for Cloud Processes of the Main Precipitation Systems in Brazil: A Contribution to Cloud Resolving Modeling and to the GPM …
The anatomy of the proximal radius: implications on fracture implant design.
Background The proximal radius features a complex anatomy. Several studies have been published on the anatomy using different technical approaches; however, most of these studies were conducted with a special focus on parameters relevant to radial prosthetic design. The purpose of our study was to explore the complex geometry of the proximal radius with regard to fracture implant design. Methods Our computed tomography-based measurements of 78 multiplanar reformatted radii allow for exact assessment of its geometry and offer a scientific rationale towards the design of fracture implants. We conducted measurements on the radial head, the radial neck, the radial tuberosity, the radial head-to…
Constraints on Minute-Scale Transient Astrophysical Neutrino Sources
High-energy neutrino emission has been predicted for several short-lived astrophysical transients including gamma-ray bursts (GRBs), core-collapse supernovae with choked jets, and neutron star mergers. IceCube's optical and x-ray follow-up program searches for such transient sources by looking for two or more muon neutrino candidates in directional coincidence and arriving within 100 s. The measured rate of neutrino alerts is consistent with the expected rate of chance coincidences of atmospheric background events and no likely electromagnetic counterparts have been identified in Swift follow-up observations. Here, we calculate generic bounds on the neutrino flux of short-lived transient so…
Midterm follow-up after DC-BEAD™-TACE of Hepatocellular Carcinoma (HCC)
Abstract Aim To determine local response, its predictors and survival and complication rates after DC-Bead™-TACE in patients with hepatocellular carcinoma (HCC). Materials and methods DC-Beads™ are non-resorbable, polyvinyl-alcoholic hydrophilic microspheres. They release high amounts of chemotherapeutics directly into the tumour. Delivery is sustained over time, tumour feeders are embolised. We used beads from 100–300 to 500–700 μm loaded with Doxorubicin (max. 150 mg/4 ml). Fifty patients (mean age: 68.5 ± 8.8 years) with HCC were analysed. DC-Bead™-TACE was performed once or repeated in two-month intervals. Imaging scans (CT or MRI) were done one-month following each procedure. To evalua…
Overview paper: New insights into aerosol and climate in the Arctic
Motivated by the need to predict how the Arctic atmosphere will change in a warming world, this article summarizes recent advances made by the research consortium NETCARE (Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments) that contribute to our fundamental understanding of Arctic aerosol particles as they relate to climate forcing. The overall goal of NETCARE research has been to use an interdisciplinary approach encompassing extensive field observations and a range of chemical transport, earth system, and biogeochemical models. Several major findings and advances have emerged from NETCARE since its formation in 2013. (1) Unexpectedly high summer…
Influx of African biomass burning aerosol during the Amazonian dry season through layered transatlantic transport of black carbon-rich smoke
Black carbon (BC) aerosols influence the Earth's atmosphere and climate, but their microphysical properties, spatiotemporal distribution, and long-range transport are not well constrained. This study presents airborne observations of the transatlantic transport of BC-rich African biomass burning (BB) smoke into the Amazon Basin using a Single Particle Soot Photometer (SP2) as well as several complementary techniques. We base our results on observations of aerosols and trace gases off the Brazilian coast onboard the HALO (High Altitude and LOng range) research aircraft during the ACRIDICON-CHUVA campaign in September 2014. During flight AC19 over land and ocean at the northeastern coastline …
Aerosol properties, source identification, and cloud processing in orographic clouds measured by single particle mass spectrometry on a Central European mountain site during HCCT-2010
Abstract. Cloud residues and out-of-cloud aerosol particles with diameters between 150 and 900 nm have been analysed by on-line single particle aerosol mass spectrometry during the six-week study HCCT-2010 in September/October 2010. The measurement location was the mountain Schmücke (937 m a.s.l.) in Central Germany. More than 170 000 bipolar mass spectra from out-of-cloud aerosol particles and more than 14 000 bipolar mass spectra from cloud residual particles were obtained and were classified using a fuzzy c-means clustering algorithm. Analysis of the uncertainty of the sorting algorithm was conducted on a subset of the data by comparing the clustering output with particle-by-particle ins…
Surface modification of mineral dust particles by sulphuric acid processing: implications for CCN and IN abilities
Abstract. The ability of coated mineral dust particles to act as cloud condensation nuclei (CCN) and ice nuclei (IN) was investigated at LACIS (Leipzig Aerosol Cloud Interaction Simulator) during the FROST1- and FROST2-campaigns (Freezing of dust). Sulphuric acid was condensed on the particles which afterwards were optionally humidified, treated with ammonia vapour and/or heat. By means of aerosol mass spectrometry we found evidence that processing of mineral dust particles with sulphuric acid leads to surface modifications of the particles. These surface modifications are responsible for the observed reduction of the IN activation of the particles. The observed particle mass spectra sugges…