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  1. Article ; Online: Arecibo measurements of D-region electron densities during sunset and sunrise

    C. Baumann / A. Kero / S. Raizada / M. Rapp / M. P. Sulzer / P. T. Verronen / J. Vierinen

    Annales Geophysicae, Vol 40, Pp 519-

    implications for atmospheric composition

    2022  Volume 530

    Abstract: ... sunrise. This asymmetry extends from solar zenith angles (SZAs) of 80 to 100 ∘ . This D-region asymmetry ... Climate Model incorporating a subset SIC's ion chemistry (WACCM-D). Both models also show a D-region sunrise ... sunset asymmetry. However, WACCM-D compares slightly better to the observations than SIC, especially ...

    Abstract Earth's lower ionosphere is the region where terrestrial weather and space weather come together. Here, between 60 and 100 km altitude, solar radiation governs the diurnal cycle of the ionized species. This altitude range is also the place where nanometre-sized dust particles, recondensed from ablated meteoric material, exist and interact with free electrons and ions of the ionosphere. This study reports electron density measurements from the Arecibo incoherent-scatter radar being performed during sunset and sunrise conditions. An asymmetry of the electron density is observed, with higher electron density during sunset than during sunrise. This asymmetry extends from solar zenith angles (SZAs) of 80 to 100 ∘ . This D-region asymmetry can be observed between 95 and 75 km altitude. The electron density observations are compared to the one-dimensional Sodankylä Ion and Neutral Chemistry (SIC) model and a variant of the Whole Atmosphere Community Climate Model incorporating a subset SIC's ion chemistry (WACCM-D). Both models also show a D-region sunrise–sunset asymmetry. However, WACCM-D compares slightly better to the observations than SIC, especially during sunset, when the electron density gradually fades away. An investigation of the electron density continuity equation reveals a higher electron–ion recombination rate than the fading ionization rate during sunset. The recombination reactions are not fast enough to closely match the fading ionization rate during sunset, resulting in excess electron density. At lower altitudes electron attachment to neutrals and their detachment from negative ions play a significant role in the asymmetry as well. A comparison of a specific SIC version incorporating meteoric smoke particles (MSPs) to the observations revealed no sudden changes in electron density as predicted by the model. However, the expected electron density jump (drop) during sunrise (sunset) occurs at 100 ∘ SZA when the radar signal is close to the noise floor, making a clear falsification of MSPs' influence ...
    Keywords Science ; Q ; Physics ; QC1-999 ; Geophysics. Cosmic physics ; QC801-809
    Subject code 541
    Language English
    Publishing date 2022-08-01T00:00:00Z
    Publisher Copernicus Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Neuronal Presentation of Antigen and Its Possible Role in Parkinson's Disease.

    Hobson, Benjamin D / Sulzer, David

    Journal of Parkinson's disease

    2022  Volume 12, Issue s1, Page(s) S137–S147

    Abstract: Patients with Parkinson's disease (PD) and other synucleinopathies often exhibit autoimmune features, including CD4+ and some CD8+ T lymphocytes that recognize epitopes derived from alpha-synuclein. While neurons have long been considered to not present ... ...

    Abstract Patients with Parkinson's disease (PD) and other synucleinopathies often exhibit autoimmune features, including CD4+ and some CD8+ T lymphocytes that recognize epitopes derived from alpha-synuclein. While neurons have long been considered to not present antigens, recent data indicate that they can be induced to do so, particularly in response to interferons and other forms of stress. Here, we review literature on neuronal antigen presentation and its potential role in PD. Although direct evidence for CD8+ T cell-mediated neuronal death is lacking in PD, neuronal antigen presentation appears central to the pathology of Rasmussen's encephalitis, a pediatric neurological disorder driven by cytotoxic T cell infiltration and neuroinflammation. Emerging data suggest that T cells enter the brain in PD and other synucleinopathies, where the majority of neuromelanin-containing substantia nigra and locus coeruleus neurons express MHC Class I molecules. In cell culture, CD8+ T cell recognition of antigen:MHC Class I complexes on neuronal membranes leads to cytotoxic responses and neuronal cell death. Recent animal models suggest the possibility of T cell autoreactivity to mitochondrial antigens in PD. It remains unclear if neuronal antigen presentation plays a role in PD or other neurodegenerative disorders, and efforts are underway to better elucidate the potential impact of autoimmune responses on neurodegeneration.
    MeSH term(s) Animals ; Epitopes ; Histocompatibility Antigens Class I ; Interferons ; Neurons/metabolism ; Parkinson Disease/metabolism ; Synucleinopathies ; alpha-Synuclein/metabolism
    Chemical Substances Epitopes ; Histocompatibility Antigens Class I ; alpha-Synuclein ; Interferons (9008-11-1)
    Language English
    Publishing date 2022-03-07
    Publishing country Netherlands
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Extramural
    ZDB-ID 2620609-2
    ISSN 1877-718X ; 1877-7171
    ISSN (online) 1877-718X
    ISSN 1877-7171
    DOI 10.3233/JPD-223153
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  3. Article ; Online: Preparation of Sulfonyl Chlorides by Oxidative Chlorination of Thiols and Disulfides using HNO

    Sulzer, Niklas / Polterauer, Dominik / Hone, Christopher A / Kappe, C Oliver

    ChemSusChem

    2024  , Page(s) e202400292

    Abstract: A continuous flow metal-free protocol for the synthesis of sulfonyl chlorides from thiols and disulfides in the presence of nitric acid, hydrochloric acid and oxygen was developed. The influence of the reaction parameters was investigated under batch and ...

    Abstract A continuous flow metal-free protocol for the synthesis of sulfonyl chlorides from thiols and disulfides in the presence of nitric acid, hydrochloric acid and oxygen was developed. The influence of the reaction parameters was investigated under batch and flow conditions. Online
    Language English
    Publishing date 2024-03-13
    Publishing country Germany
    Document type Journal Article
    ISSN 1864-564X
    ISSN (online) 1864-564X
    DOI 10.1002/cssc.202400292
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: The chemical tools for imaging dopamine release.

    Post, Michael R / Sulzer, David

    Cell chemical biology

    2021  Volume 28, Issue 6, Page(s) 748–764

    Abstract: Dopamine is a modulatory neurotransmitter involved in learning, motor functions, and reward. Many neuropsychiatric disorders, including Parkinson's disease, autism, and schizophrenia, are associated with imbalances or dysfunction in the dopaminergic ... ...

    Abstract Dopamine is a modulatory neurotransmitter involved in learning, motor functions, and reward. Many neuropsychiatric disorders, including Parkinson's disease, autism, and schizophrenia, are associated with imbalances or dysfunction in the dopaminergic system. Yet, our understanding of these pervasive public health issues is limited by our ability to effectively image dopamine in humans, which has long been a goal for chemists and neuroscientists. The last two decades have witnessed the development of many molecules used to trace dopamine. We review the small molecules, nanoparticles, and protein sensors used with fluorescent microscopy/photometry, MRI, and PET that shape dopamine research today. None of these tools observe dopamine itself, but instead harness the biology of the dopamine system-its synthetic and metabolic pathways, synaptic vesicle cycle, and receptors-in elegant ways. Their advantages and weaknesses are covered here, along with recent examples and the chemistry and biology that allow them to function.
    MeSH term(s) Dopamine/analysis ; Dopamine/metabolism ; Humans ; Parkinson Disease/diagnosis ; Parkinson Disease/metabolism
    Chemical Substances Dopamine (VTD58H1Z2X)
    Language English
    Publishing date 2021-04-23
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ISSN 2451-9448
    ISSN (online) 2451-9448
    DOI 10.1016/j.chembiol.2021.04.005
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  5. Article ; Online: Tailoring the Gibbs Free Energy of the Nitroxide Exchange Reaction: Substituent and Solvent Effects.

    Sulzer, David / Bihlmeier, Angela

    The journal of physical chemistry. A

    2021  Volume 125, Issue 35, Page(s) 7616–7624

    Abstract: A quantum chemical study of the nitroxide exchange reaction is presented. Inspired by the recent use of this reaction in the synthesis of dynamic covalent polymer networks, we studied the influence of substituents and solvents on the Gibbs free energy, ... ...

    Abstract A quantum chemical study of the nitroxide exchange reaction is presented. Inspired by the recent use of this reaction in the synthesis of dynamic covalent polymer networks, we studied the influence of substituents and solvents on the Gibbs free energy, which plays a crucial role for both the reversibility of the reaction and the extent of product formation. We provide accurate benchmark values based on CCSD(T) and COSMO-RS theory for a series of structural modifications and make suggestions for improving the molecular building blocks used so far.
    Language English
    Publishing date 2021-08-30
    Publishing country United States
    Document type Journal Article
    ISSN 1520-5215
    ISSN (online) 1520-5215
    DOI 10.1021/acs.jpca.1c04864
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: 5-HT1B receptors mediate dopaminergic inhibition of vesicular fusion and GABA release from striatonigral synapses.

    Molinari, Maya / Lieberman, Ori J / Sulzer, David / Santini, Emanuela / Borgkvist, Anders

    bioRxiv : the preprint server for biology

    2024  

    Abstract: The substantia nigra pars reticulata (SNr), a crucial basal ganglia output nucleus, contains a dense expression of dopamine D1 receptors (D1Rs), along with dendrites belonging to dopaminergic neurons of substantia nigra pars compacta. These D1Rs are ... ...

    Abstract The substantia nigra pars reticulata (SNr), a crucial basal ganglia output nucleus, contains a dense expression of dopamine D1 receptors (D1Rs), along with dendrites belonging to dopaminergic neurons of substantia nigra pars compacta. These D1Rs are primarily located on the terminals of striatonigral medium spiny neurons, suggesting their involvement in the regulation of neurotransmitter release from the direct pathway in response to somatodendritic dopamine release. To explore the hypothesis that D1Rs modulate GABA release from striatonigral synapses, we conducted optical recordings of striatonigral activity and postsynaptic patch-clamp recordings from SNr neurons in the presence of dopamine and D1R agonists. We found that dopamine inhibits optogenetically triggered striatonigral GABA release by modulating vesicle fusion and Ca
    Language English
    Publishing date 2024-03-14
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2024.03.14.584991
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  7. Article: Die Suche nach der Relevanz in einer informationsgesättigten Welt

    Sulzer, Dieter

    Angewandte Gérontologie Appliquée

    2018  Volume 3, Issue 3, Page(s) 43

    Keywords Alter. ; Information ; Gerontologie ; Wissenschaft ; Qualität ; Vermittlung
    Language German
    Document type Article
    ISSN 2297-5160
    Database bibnet.org

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  8. Article: La quête de la pertinence dans un monde saturé d'informations

    Sulzer, Dieter

    Angewandte Gérontologie Appliquée

    2018  Volume 3, Issue 3, Page(s) 43

    Keywords Alter. ; Information ; Gerontologie ; Wissenschaft ; Qualität ; Vermittlung
    Language French
    Document type Article
    ISSN 2297-5160
    Database bibnet.org

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  9. Article ; Online: Autoimmungastritis.

    Venerito, Marino / Sulzer, Sabrina / Jechorek, Dörthe

    Deutsche medizinische Wochenschrift (1946)

    2022  Volume 147, Issue 8, Page(s) 451–459

    Abstract: Autoimmune gastritis (AIG) is a chronic immune-mediated inflammation of the gastric corpus/fundus mucosa leading to progressive atrophy of the oxyntic gastric glands (AOM) and their consecutive loss of function. Possible clinical consequences of AIG ... ...

    Title translation Clinical management of autoimmune gastritis.
    Abstract Autoimmune gastritis (AIG) is a chronic immune-mediated inflammation of the gastric corpus/fundus mucosa leading to progressive atrophy of the oxyntic gastric glands (AOM) and their consecutive loss of function. Possible clinical consequences of AIG include iron deficiency anemia, pernicious anemia, gastric neuroendocrine tumors (gNET), and gastric adenocarcinoma. This article provides a review of interdisciplinary aspects of the diagnosis and treatment of AIG.
    MeSH term(s) Anemia, Iron-Deficiency/diagnosis ; Anemia, Iron-Deficiency/pathology ; Anemia, Iron-Deficiency/therapy ; Autoimmune Diseases/diagnosis ; Autoimmune Diseases/therapy ; Gastric Mucosa/pathology ; Gastritis/diagnosis ; Gastritis/therapy ; Humans ; Stomach Neoplasms/diagnosis ; Stomach Neoplasms/pathology ; Stomach Neoplasms/therapy
    Language German
    Publishing date 2022-04-11
    Publishing country Germany
    Document type Journal Article ; Review
    ZDB-ID 200446-x
    ISSN 1439-4413 ; 0012-0472
    ISSN (online) 1439-4413
    ISSN 0012-0472
    DOI 10.1055/a-1520-3562
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  10. Article: Similarities and differences between nigral and enteric dopaminergic neurons unravel distinctive involvement in Parkinson's disease.

    Chalazonitis, Alcmène / Rao, Meenakshi / Sulzer, David

    NPJ Parkinson's disease

    2022  Volume 8, Issue 1, Page(s) 50

    Abstract: In addition to the well-known degeneration of midbrain dopaminergic neurons, enteric neurons can also be affected in neurodegenerative disorders such as Parkinson's disease (PD). Dopaminergic neurons have recently been identified in the enteric nervous ... ...

    Abstract In addition to the well-known degeneration of midbrain dopaminergic neurons, enteric neurons can also be affected in neurodegenerative disorders such as Parkinson's disease (PD). Dopaminergic neurons have recently been identified in the enteric nervous system (ENS). While ENS dopaminergic neurons have been shown to degenerate in genetic mouse models of PD, analyses of their survival in enteric biopsies of PD patients have provided inconsistent results to date. In this context, this review seeks to highlight the distinctive and shared factors and properties that control the evolution of these two sets of dopaminergic neurons from neuronal precursors to aging neurons. Although their cellular sources and developmental times of origin differ, midbrain and ENS dopaminergic neurons express many transcription factors in common and their respective environments express similar neurotrophic molecules. For example, Foxa2 and Sox6 are expressed by both populations to promote the specification, differentiation, and long-term maintenance of the dopaminergic phenotype. Both populations exhibit sustained patterns of excitability that drive intrinsic vulnerability over time. In disorders such as PD, colon biopsies have revealed aggregation of alpha-synuclein in the submucosal plexus where dopaminergic neurons reside and lack blood barrier protection. Thus, these enteric neurons may be more susceptible to neurotoxic insults and aggregation of α-synuclein that spreads from gut to midbrain. Under sustained stress, inefficient autophagy leads to neurodegeneration, GI motility dysfunction, and PD symptoms. Recent findings suggest that novel neurotrophic factors such as CDNF have the potential to be used as neuroprotective agents to prevent and treat ENS symptoms of PD.
    Language English
    Publishing date 2022-04-22
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 2819218-7
    ISSN 2373-8057
    ISSN 2373-8057
    DOI 10.1038/s41531-022-00308-9
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