Refine
Year of publication
Document Type
- Preprint (611)
- Article (435)
- Conference Proceeding (1)
- Report (1)
- Working Paper (1)
Has Fulltext
- yes (1049)
Is part of the Bibliography
- no (1049)
Keywords
- Heavy Ion Experiments (20)
- Hadron-Hadron scattering (experiments) (11)
- Hadron-Hadron Scattering (8)
- Heavy-ion collision (5)
- Collective Flow (4)
- Quark-Gluon Plasma (4)
- Jets (3)
- Jets and Jet Substructure (3)
- (surface) partial differential equations (2)
- 3D spatio-temporal resolved mathematical models (2)
- Atmospheric chemistry (2)
- COVID-19 (2)
- Epilepsy (2)
- Experimental nuclear physics (2)
- Experimental particle physics (2)
- Finite Volumes (2)
- Germany (2)
- Heavy Quark Production (2)
- Immunotherapy (2)
- LHC (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Non-small cell lung cancer (2)
- Oncology (2)
- Particle Correlations and Fluctuations (2)
- Particle and resonance production (2)
- Particle correlations and fluctuations (2)
- Quarkonium (2)
- acute myeloid leukemia (2)
- computational virology (2)
- immunotherapy (2)
- massively parallel multigrid solvers (2)
- realistic geometries (2)
- viral dynamics (2)
- within-host viral modelling (2)
- 140Ce (1)
- 900 GeV (1)
- ACURATE neo (1)
- AIS (1)
- ALICE (1)
- ALICE detector (1)
- APRI (1)
- ASCT (1)
- Accelerators & Beams (1)
- Acute myeloid leukemia (1)
- Adherens junctions (1)
- Aneurysmal subarachnoid hemorrhage (1)
- Anti-nuclei (1)
- Antibody therapy (1)
- Artificial Intelligence (1)
- Atomic and Molecular Physics (1)
- Atomic, Molecular & Optical (1)
- BCOR (1)
- BCORL1 (1)
- BI1361849 (1)
- Bamlanivimab (1)
- Biodiversity Data (1)
- Biogeochemistry (1)
- Biomarkers (1)
- Biomonitoring (1)
- Bladder cancer (1)
- Blood-brain barrier (1)
- Bloodstream infection (1)
- Bloodstream infections (1)
- Boosted Jets (1)
- Botanical Collections (1)
- Brain tumor (1)
- Burkholderia arboris (1)
- CD36 (1)
- CHIP (1)
- CHRNA10 (1)
- CHRNA7 (1)
- CHRNA9 (1)
- CTLA-4 (1)
- CV9202 (1)
- CVID (1)
- Cancer (1)
- Cancer genomics (1)
- Casirivimab (1)
- Centrality Class (1)
- Centrality Selection (1)
- Charged-particle multiplicity (1)
- Checkpoint inhibitor (1)
- Clinical Trials and Observations (1)
- Clinical trial (1)
- Cluster (1)
- Cohort studies (1)
- Collective Flow, (1)
- Conservation (1)
- Correlative electron and light microscopy (1)
- DBS (1)
- DSS /AOM (1)
- Diagnostic markers (1)
- Digitization (1)
- Electromagnetic transitions (1)
- Electron tomography (1)
- Electron-pion identification (1)
- Electroweak interaction (1)
- Entomology (1)
- Epidemiology (1)
- European Society for Immunodeficiencies (ESID) (1)
- Everolimus resistance (1)
- Evidence-based guidelines (1)
- Extended Glasgow outcome scale (eGOS) (1)
- Extended donor criteria (1)
- FDG-PET/CT (1)
- FIB-4 (1)
- Fibre/foam sandwich radiator (1)
- Freshwater ecology (1)
- GdIr2Si2 (1)
- German PID-NET registry (1)
- Glioma (1)
- Graft function (1)
- Graft survival (1)
- Gram negative bacteria (1)
- HBV (1)
- HDAC-inhibition (1)
- HNSCC (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Hard Scattering (1)
- Head neck cancer (1)
- Heavy Ion Experiment (1)
- Hematology (1)
- Hematopoietic stem cell transplantation (1)
- Herbaria (1)
- Hypofractionated radiotherapy (1)
- ICU (1)
- IL -17 (1)
- IL -23 (1)
- IL 23p19 knockout mouse (1)
- ISS (1)
- IgG substitution therapy (1)
- Imdevimab (1)
- Immunomonitoring (1)
- Incidence (1)
- Induction therapy (1)
- Intensive care units (1)
- Invariant Mass Distribution (1)
- Invasive species (1)
- Ionisation energy loss (1)
- Isoflurane (1)
- Jet Physics (1)
- Jet Substructure (1)
- Lesion (1)
- Liver transplantation (1)
- Locally advanced (1)
- Long term output (1)
- Lymphocytes (1)
- Lymphoid tissues (1)
- MACS (1)
- MRI (1)
- Magnetic resonance imaging (MRI) (1)
- Marginal grafts (1)
- Material budget (1)
- Mechanisms of disease (1)
- Minimum Bias (1)
- Models & methods for nuclear reactions (1)
- Molecular diagnostic testing (1)
- Molecular matched therapy (1)
- Molecular medicine (1)
- Molecular profiling (1)
- Monte Carlo (1)
- Mott transition (1)
- Multi-Parton Interactions (1)
- Multi-wire proportional drift chamber (1)
- Multiple parton interactions (1)
- Multivariate analysis (1)
- Myeloid Neoplasia (1)
- NMR spectroscopy (1)
- NSCLC (1)
- Neural network (1)
- Neutron physics (1)
- Neutropenia (1)
- Nivolumab (1)
- Nuclear reactions (1)
- Organ rinse (1)
- Organ shortage (1)
- Osteoporosis (1)
- P2X7 receptor (1)
- PD-1 (1)
- PD-1 inhibitor (1)
- PDEs (1)
- PID prevalence (1)
- PYTHIA (1)
- Particle and Resonance Production (1)
- Pb–Pb collisions (1)
- Phylogenomics (1)
- Pneumonia (1)
- Poecilia mexicana (1)
- Polarization (1)
- Population genetics (1)
- Production Cross Section (1)
- Properties of Hadrons (1)
- Psoriasis vulgaris (1)
- QCD (1)
- Quark Deconfinement (1)
- Quark Gluon Plasma (1)
- Quark Production (1)
- RNA (1)
- RNA decay (1)
- Radiation detectors (1)
- Radiative capture (1)
- Radical cystectomy (1)
- Radiotherapy (1)
- Rapidity Range (1)
- Registries (1)
- Relativistic heavy-ion collisions (1)
- Renal cell carcinoma (1)
- Research Infrastructure (1)
- Resolution Parameter (1)
- Resonance reactions (1)
- SMAD (1)
- Semantics (1)
- Sexual selection (1)
- Status epilepticus (1)
- Stenotrophomonas maltophilia (1)
- Stentoplasty (1)
- Systematic Uncertainty (1)
- T cell/histiocyte rich large B cell lymphoma (1)
- TAVR (1)
- TGFβ (1)
- TR (1)
- Tacrolimus (1)
- Targeted therapy (1)
- Taxonomy (1)
- Thermodynamics (1)
- Thoracic trauma (1)
- Thrombotic microangiopathy (1)
- Thrombotic thrombocytopenic purpura (1)
- Time Projection Chamber (1)
- TmRh2Si2 (1)
- Tracking (1)
- Transition radiation detector (1)
- Transitional cell carcinoma (1)
- Transverse momentum (1)
- Treatment (1)
- Trigger (1)
- Tumor growth (1)
- Urothelial cancer (1)
- VIM (1)
- Vector Boson Production (1)
- Vertebral augmentation (1)
- Vertebral body stenting (1)
- Vertebral fracture (1)
- Viral load (1)
- X-ray crystallography (1)
- X-ray irradiation (1)
- Xenon-based gas mixture (1)
- acoustic radiation force impulse imaging (1)
- adaptation (1)
- advanced melanoma (1)
- adversity (1)
- age (1)
- allostasis (1)
- anti-epileptic drug (1)
- aortic stenosis (1)
- autologous stem cell transplantation (1)
- biomarker (1)
- blood cell mutations (1)
- brain metastases (1)
- brain metastasis (1)
- brain shift (1)
- burkholderia (1)
- burkholderia cepacia complex infections (1)
- calcium dynamics (1)
- calcium-independent phospholipase A2β (1)
- capture (1)
- cdk2/cyclin A (1)
- cerebral pseudoprogression (1)
- cerium (1)
- chemoconvulsant (1)
- chemotherapy (1)
- chronic colitis (1)
- clonal dominance (1)
- clonal haematopoiesis (1)
- clonal hematopoiesis (1)
- clonal transfer (1)
- colon cancer (1)
- community assembly (1)
- complete response (1)
- complex systems (1)
- coping (1)
- correlated electrons (1)
- cross-section (1)
- cytarabine dose (1)
- dE/dx (1)
- detailed modeling (1)
- detector (1)
- diffuse large B cell lymphoma (1)
- discontinuation (1)
- discontinuous dose dependency (1)
- disease outbreaks (1)
- disease progression (1)
- disorder (1)
- distributed computation (1)
- dynamic system (1)
- ectosomes (1)
- elderly (1)
- electrical stimulation (1)
- electrophoresis (1)
- epileptogenesis (1)
- essential tremor (1)
- everolimus (1)
- exosomes (1)
- experimental results (1)
- extracellular vesicles (1)
- familial amyloid nephropathy with urticaria and deafness (1)
- female choice (1)
- fibrotest (1)
- flux growth (1)
- gel (1)
- gene expression profiling (1)
- gene signature (1)
- generalized additive model (1)
- genome (1)
- glioblastoma (1)
- guidelines (1)
- head and neck squamous cell carcinoma (1)
- healthcare systems (1)
- heart failure (1)
- heavy ion experiments (1)
- hematopoietic stem cells (1)
- hematopoietic stress (1)
- hepatitis C virus (1)
- hepatitis C virus (HCV) (1)
- hippocampal sclerosis (1)
- homeostasis (1)
- host response (1)
- hybrid (1)
- hypoxia (1)
- immune checkpoint blockade (1)
- immune checkpoint inhibitors (1)
- immune checkpoint inhibitors (ICI) (1)
- immune modulation (1)
- immune related adverse events (irAE) (1)
- infections (1)
- inflammasome (1)
- inflammation (1)
- information storage (1)
- inpatient hospital admissions (1)
- interleukin-1β (1)
- leukemia (1)
- liver metastasis (1)
- local information dynamics (1)
- lockdown (1)
- loss-of-function (1)
- low-dose radiation therapy (1)
- lung cancer (1)
- mRNA active cancer immunotherapy (1)
- magnetism (1)
- mathematical models of viral RNA cycle (1)
- medical device (1)
- medical informatics initiative (1)
- mental health (1)
- metastatic renal cell carcinoma (1)
- microbial colonization (1)
- microparticles (1)
- microvesicles (1)
- minimal information requirements (1)
- mouthwash (1)
- mouthwash solution (1)
- n_TOF (1)
- neoadjuvant immunochemotherapy (1)
- neural dynamics (1)
- neurological complication (1)
- neurological side effects (1)
- neuron (1)
- neutron (1)
- nodular lymphocyte predominant Hodgkin lymphoma (1)
- non-independent mate choice (1)
- non-invasive fibrosis assessment (1)
- noncoding RNA (1)
- ntracellular signaling (1)
- nucleosynthesis (1)
- organic conductor (1)
- outbreak (1)
- p+p collisions (1)
- p47phox (1)
- pandemic (1)
- parallel (1)
- parameter estimation (1)
- patterns of progression (1)
- pembrolizumab (1)
- perioperative ischemia (1)
- phase IV (1)
- point shear wave elastography (1)
- postoperative radiochemotherapy (1)
- postoperative radiotherapy (1)
- predator recognition (1)
- predictive coding (1)
- pressure (1)
- primary immunodeficiency (PID) (1)
- propensity score matching (1)
- pulsed-field (1)
- quark gluon plasma (1)
- registry for primary immunodeficiency (1)
- reproducibility (1)
- rigor (1)
- risk stratification (1)
- s-process (1)
- second-line (1)
- second-line immunotherapy (1)
- soil bacteria communities (1)
- somatic mutations (1)
- spatio-temporal analysis (1)
- standardization (1)
- status epilepticus (1)
- stereotactic radiosurgery (1)
- stress (1)
- survival (1)
- targeted therapy (1)
- temporal lobe epilepsy (1)
- transcatheter aortic valve replacement (1)
- transfemoral (1)
- transient elastography (1)
- treatment resistance (1)
- tumor microenvironment (1)
- university hospitals (1)
- uveal melanoma (1)
- variable selection (1)
- ventralis intermedius nucleus (1)
- visual system (1)
- voltage sensitive dye imaging (1)
Institute
- Physik (955)
- Frankfurt Institute for Advanced Studies (FIAS) (853)
- Informatik (822)
- Medizin (66)
- Geowissenschaften (9)
- Biowissenschaften (5)
- ELEMENTS (3)
- Informatik und Mathematik (3)
- Institut für Ökologie, Evolution und Diversität (3)
- Biochemie und Chemie (2)
The transcription factor Meis1 drives myeloid leukemogenesis in the context of Hox gene overexpression but is currently considered undruggable. We therefore investigated whether myeloid progenitor cells transformed by Hoxa9 and Meis1 become addicted to targetable signaling pathways. A comprehensive (phospho)proteomic analysis revealed that Meis1 increased Syk protein expression and activity. Syk upregulation occurs through a Meis1-dependent feedback loop. By dissecting this loop, we show that Syk is a direct target of miR-146a, whose expression is indirectly regulated by Meis1 through the transcription factor PU.1. In the context of Hoxa9 overexpression, Syk signaling induces Meis1, recapitulating several leukemogenic features of Hoxa9/Meis1-driven leukemia. Finally, Syk inhibition disrupts the identified regulatory loop, prolonging survival of mice with Hoxa9/Meis1-driven leukemia.
Bloodstream infections (BSI) are a frequent complication in patients with hematological and oncological diseases. However, the impact of different bacterial species causing BSI and of multiple BSI remains incompletely understood. We performed a retrospective study profiling 637 bacterial BSI episodes in hematological and oncological patients. Based on the 30-day (30d) overall survival (OS), we analyzed different types of multiple BSI and grouped BSI-associated bacteria into clusters followed by further assessment of clinical and infection-related characteristics. We discovered that polymicrobial BSI (different organisms on the first day of a BSI episode) and sequential BSI (another BSI before the respective BSI episode) were associated with a worse 30d OS. Different bacterial groups could be classified into three BSI outcome clusters based on 30d OS: favorable (FAV) including mainly common skin contaminants, Escherichia spp. and Streptococcus spp.; intermediate (INT) including mainly Enterococcus spp., vancomycin-resistant Enterococcus spp., and multidrug-resistant gram-negative bacteria (MDRGN); and adverse (ADV) including MDRGN with an additional carbapenem-resistance (MDRGN+CR). A polymicrobial or sequential BSI especially influenced the outcome in the combination of two INT cluster BSI. The presence of a polymicrobial BSI and the assignment into the BSI outcome clusters were identified as independent risk factors for 30d mortality in a Cox multivariate regression analysis. The assignment to a BSI outcome cluster and the differentiated perspective of multiple BSI open new insights into the prognosis of patients with BSI and should be further validated in other patient cohorts.
Allogeneic hematopoietic stem cell transplantation (allo-HSCT) offers potential cure to acute myeloid leukemia (AML) patients. However, infections with commensal bacteria are an important cause for non-relapse mortality (NRM). We have previously described the impact of multidrug-resistant organism (MDRO) colonization on the survival of allo-HSCT patients. In the aforementioned publication, according to consensus, we there did not consider the opportunistic gram-negative bacterium Stenotrophomonas maltophilia (S. maltophilia) to be an MDRO. Since rate of S. maltophilia colonization is increasing, and it is not known whether this poses a risk for allo-HSCT patients, we here analyzed here its effect on the previously described and now extended patient cohort. We report on 291 AML patients undergoing allo-HSCT. Twenty of 291 patients (6.9%) were colonized with S. maltophilia. Colonized patients did not differ from non-colonized patients with respect to their age, remission status before allo-HSCT, donor type and HSCT-comorbidity index. S. maltophilia colonized patients had a worse overall survival (OS) from 6 months up to 60 months (85% vs. 88.1% and 24.7% vs. 59.7%; p = 0.007) due to a higher NRM after allo-HSCT (6 months: 15% vs. 4.8% and 60 months: 40.1% vs. 16.2% p = 0.003). The main cause of mortality in colonized patients was infection (46.2% of all deaths) and in non-colonized patients relapse (58.8% of all deaths). 5/20 colonized patients developed an invasive infection with S. maltophilia. The worse OS after allo-HSCT due to higher infection related mortality might implicate the screening of allo-HSCT patients for S. maltophilia and a closer observation of colonized patients as outpatients.
Background: Preclinical studies demonstrate synergism between cancer immunotherapy and local radiation, enhancing anti-tumor effects and promoting immune responses. BI1361849 (CV9202) is an active cancer immunotherapeutic comprising protamine-formulated, sequence-optimized mRNA encoding six non-small cell lung cancer (NSCLC)-associated antigens (NY-ESO-1, MAGE-C1, MAGE-C2, survivin, 5T4, and MUC-1), intended to induce targeted immune responses.
Methods: We describe a phase Ib clinical trial evaluating treatment with BI1361849 combined with local radiation in 26 stage IV NSCLC patients with partial response (PR)/stable disease (SD) after standard first-line therapy. Patients were stratified into three strata (1: non-squamous NSCLC, no epidermal growth factor receptor (EGFR) mutation, PR/SD after ≥4 cycles of platinum- and pemetrexed-based treatment [n = 16]; 2: squamous NSCLC, PR/SD after ≥4 cycles of platinum-based and non-platinum compound treatment [n = 8]; 3: non-squamous NSCLC, EGFR mutation, PR/SD after ≥3 and ≤ 6 months EGFR-tyrosine kinase inhibitor (TKI) treatment [n = 2]). Patients received intradermal BI1361849, local radiation (4 × 5 Gy), then BI1361849 until disease progression. Strata 1 and 3 also had maintenance pemetrexed or continued EGFR-TKI therapy, respectively. The primary endpoint was evaluation of safety; secondary objectives included assessment of clinical efficacy (every 6 weeks during treatment) and of immune response (on Days 1 [baseline], 19 and 61).
Results: Study treatment was well tolerated; injection site reactions and flu-like symptoms were the most common BI1361849-related adverse events. Three patients had grade 3 BI1361849-related adverse events (fatigue, pyrexia); there was one grade 3 radiation-related event (dysphagia). In comparison to baseline, immunomonitoring revealed increased BI1361849 antigen-specific immune responses in the majority of patients (84%), whereby antigen-specific antibody levels were increased in 80% and functional T cells in 40% of patients, and involvement of multiple antigen specificities was evident in 52% of patients. One patient had a partial response in combination with pemetrexed maintenance, and 46.2% achieved stable disease as best overall response. Best overall response was SD in 57.7% for target lesions.
Conclusion: The results support further investigation of mRNA-based immunotherapy in NSCLC including combinations with immune checkpoint inhibitors.
Trial registration: ClinicalTrials.gov identifier: NCT01915524.
Background: Patients with locally advanced bladder cancer (cT3/4 cN0/N+ cM0) have a poor prognosis despite radical surgical therapy and perioperative chemotherapy. Preliminary data suggest that the combination of radiation and immunotherapy does not lead to excess toxicity and may have synergistic (abscopal) anti-tumor effects. We hypothesize that the combined preoperative application of the PD-1 checkpoint-inhibitor Nivolumab with concomitant radiation therapy of the bladder and pelvic region followed by radical cystectomy with standardized lymphadenectomy is safe and feasible and might improve outcome for patients with locally advanced bladder cancer.
Methods: Study design: “RACE IT” (AUO AB 65/18) is an investigator initiated, prospective, multicenter, open, single arm phase II trial sponsored by Technical University Munich. Study drug and funding are provided by the company Bristol-Myers Squibb.
Study treatment: Patients will receive Nivolumab 240 mg i.v. every 2 weeks for 4 cycles preoperatively with concomitant radiation therapy of bladder and pelvic region (max. 50.4 Gy). Radical cystectomy with standardized bilateral pelvic lymphadenectomy will be performed between week 11–15.
Primary endpoint: Rate of patients with completed treatment consisting of radio-immunotherapy and radical cystectomy at the end of week 15.
Secondary endpoints: Acute and late toxicity, therapy response and survival (1 year follow up).
Main inclusion criteria: Patients with histologically confirmed, locally advanced bladder cancer (cT3/4, cN0/N+), who are ineligible for neoadjuvant, cisplatin-based chemotherapy or who refuse neoadjuvant chemotherapy.
Main exclusion criteria: Patients with metastatic disease (lymph node metastasis outside pelvis or distant metastasis) or previous chemo-, immune- or radiation therapy.
Planned sample size: 33 patients, interim analysis after 11 patients.
Several clinically used drugs are derived from microorganisms that often produce them via non-ribosomal peptide synthetases (NRPS), giant megasynthases that activate and connect individual amino acids in an assembly line fashion. Since NRPS are not restricted to the incorporation of the 20 proteinogenic amino acids, their efficient manipulation would allow the biotechnological generation of several different peptides including linear, cyclic and further modified derivatives. Here we describe a detailed phylogenetic analysis of several bacterial NRPS that led to the identification of a new recombination breakpoint within the thiolation (T) domain important in natural NRPS evolution. From this an evolutionary-inspired eXchange Unit between T domains (XUT) approach was developed, which allows the assembly of NRPS fragments over a broad range of GC contents, protein similarities, and extender unit specificities, as was shown for the specific production of a proteasome inhibitor, designed and assembled from five different NRPS fragments.
The nuclear exosome and its essential co-factor, the RNA helicase MTR4, play crucial roles in several RNA degradation pathways. Besides unwinding RNA substrates for exosome-mediated degradation, MTR4 associates with RNA-binding proteins that function as adaptors in different RNA processing and decay pathways. Here, we identify and characterize the interactions of human MTR4 with a ribosome processing adaptor, NVL, and with ZCCHC8, an adaptor involved in the decay of small nuclear RNAs. We show that the unstructured regions of NVL and ZCCHC8 contain short linear motifs that bind the MTR4 arch domain in a mutually exclusive manner. These short sequences diverged from the arch-interacting motif (AIM) of yeast rRNA processing factors. Our results suggest that nuclear exosome adaptors have evolved canonical and non-canonical AIM sequences to target human MTR4 and demonstrate the versatility and specificity with which the MTR4 arch domain can recruit a repertoire of different RNA-binding proteins.
Current anti-epileptic drugs (AEDs) act on a limited set of neuronal targets, are ineffective in a third of patients with epilepsy, and do not show disease-modifying properties. MicroRNAs are small noncoding RNAs that regulate levels of proteins by post-transcriptional control of mRNA stability and translation. MicroRNA-134 is involved in controlling neuronal microstructure and brain excitability and previous studies showed that intracerebroventricular injections of locked nucleic acid (LNA), cholesterol-tagged antagomirs targeting microRNA-134 (Ant-134) reduced evoked and spontaneous seizures in mouse models of status epilepticus. Translation of these findings would benefit from evidence of efficacy in non-status epilepticus models and validation in another species. Here, we report that electrographic seizures and convulsive behavior are strongly reduced in adult mice pre-treated with Ant-134 in the pentylenetetrazol model. Pre-treatment with Ant-134 did not affect the severity of status epilepticus induced by perforant pathway stimulation in adult rats, a toxin-free model of acquired epilepsy. Nevertheless, Ant-134 post-treatment reduced the number of rats developing spontaneous seizures by 86% in the perforant pathway stimulation model and Ant-134 delayed epileptiform activity in a rat ex vivo hippocampal slice model. The potent anticonvulsant effects of Ant-134 in multiple models may encourage pre-clinical development of this approach to epilepsy therapy.
Hygroscopicity of nanoparticles produced from homogeneous nucleation in the CLOUD experiments
(2015)
Sulfuric acid, amines and oxidized organics have been found to be important compounds in the nucleation and initial growth of atmospheric particles. Because of the challenges involved in determining the chemical composition of objects with very small mass, however, the properties of the freshly nucleated particles and the detailed pathways of their formation processes are still not clear. In this study, we focus on a challenging size range, i.e. particles that have grown to diameters of 10 and 15nm following nucleation, and measure their water uptake. Water uptake constrains their chemical composition. We use a nanometer-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) at subsaturated conditions (ca. 90% relative humidity at 293 K) to measure the hygroscopicity of particles during the seventh Cosmics Leaving OUtdoor Droplets (CLOUD7) experiments performed at CERN in 2012. In CLOUD7, the hygroscopicity of nucleated nanoparticles was measured in the presence of sulfuric acid, sulfuric acid-dimethylamine, and sulfuric acid-organics derived from α-pinene oxidation. The hygroscopicity parameter Κ decreased with increasing particle size indicating decreasing acidity of particles. No clear effect of the sulfuric acid monomer concentrations on the hygroscopicities of 10nm particles produced from sulfuric acid and dimethylamine was observed, whereas the hygroscopicity of 15nm particles sharply decreased with decreasing sulfuric acid monomer concentrations. In 20 particular, when the concentrations of sulfuric acid was 5.1 x 106 molecules cm exp -3 in the gas phase, and the dimethylamine mixing ratio was 11.8 ppt, the measured Κ of 15nm particles was 0.3 ± 0.01 close to the value reported for dimethylamine sulfate (DMAS) (Κ DMAS ~ 0.28). Furthermore, the difference in Κ between sulfuric acid and sulfuric acid-dimethylamine experiments increased with increasing particle size. The Κ values of particles in the presence of sulfuric acid and organics were much smaller than those of particles in the presence of sulfuric acid and dimethylamine. This suggests that the organics produced from α-pinene ozonolysis play a significant role in particle growth already at 10nm sizes.
Hygroscopicity of nanoparticles produced from homogeneous
nucleation in the CLOUD experiments
(2016)
Sulfuric acid, amines and oxidized organics have been found to be important compounds in the nucleation and initial growth of atmospheric particles. Because of the challenges involved in determining the chemical composition of objects with very small mass, however, the properties of the freshly nucleated particles and the detailed pathways of their formation processes are still not clear. In this study, we focus on a challenging size range, i.e., particles that have grown to diameters of 10 and 15 nm following nucleation, and measure their water uptake. Water uptake is useful information for indirectly obtaining chemical composition of aerosol particles. We use a nanometer-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) at subsaturated conditions (ca. 90 % relative humidity at 293 K) to measure the hygroscopicity of particles during the seventh Cosmics Leaving OUtdoor Droplets (CLOUD7) campaign performed at CERN in 2012. In CLOUD7, the hygroscopicity of nucleated nanoparticles was measured in the presence of sulfuric acid, sulfuric acid–dimethylamine, and sulfuric acid–organics derived from α-pinene oxidation. The hygroscopicity parameter κ decreased with increasing particle size, indicating decreasing acidity of particles. No clear effect of the sulfuric acid concentration on the hygroscopicity of 10 nm particles produced from sulfuric acid and dimethylamine was observed, whereas the hygroscopicity of 15 nm particles sharply decreased with decreasing sulfuric acid concentrations. In particular, when the concentration of sulfuric acid was 5.1 × 106 molecules cm−3 in the gas phase, and the dimethylamine mixing ratio was 11.8 ppt, the measured κ of 15 nm particles was 0.31 ± 0.01: close to the value reported for dimethylaminium sulfate (DMAS) (κDMAS ∼ 0.28). Furthermore, the difference in κ between sulfuric acid and sulfuric acid–imethylamine experiments increased with increasing particle size. The κ values of particles in the presence of sulfuric acid and organics were much smaller than those of particles in the presence of sulfuric acid and dimethylamine. This suggests that the organics produced from α-pinene ozonolysis play a significant role in particle growth even at 10 nm sizes.