LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 134

Search options

  1. Article ; Online: Solvation, Surface Propensity, and Chemical Reactions of Solutes at Atmospheric Liquid-Vapor Interfaces.

    Ammann, Markus / Artiglia, Luca

    Accounts of chemical research

    2022  

    Abstract: ConspectusLiquids are of overarching importance for the atmosphere, as 72% of the Earth's surface is covered by oceans, a large number of liquid aerosol particles fill the air, and clouds hold a tiny but critical fraction of Earth's water in the air to ... ...

    Abstract ConspectusLiquids are of overarching importance for the atmosphere, as 72% of the Earth's surface is covered by oceans, a large number of liquid aerosol particles fill the air, and clouds hold a tiny but critical fraction of Earth's water in the air to influence our climate and hydrology, enabling the lives of humans and ecosystems. The surfaces of these liquids provide the interface for the transfer of gases, for nucleation processes, and for catalyzing important chemical reactions. Coupling a range of spectroscopic tools to liquid microjets has become an important approach to better understanding dynamics, structure, and chemistry at liquid interfaces. Liquid microjets offer stability in vacuum and ambient pressure environments, thus also allowing X-ray photoelectron spectroscopy (XPS) with manageable efforts in terms of differential pumping. Liquid microjets are operated at speeds sufficient to allow for a locally equilibrated surface in terms of water dynamics and solute surface partitioning. XPS is based on the emission of core-level electrons, the binding energy of which is selective for the element and its chemical environment. Inelastic scattering of electrons establishes the probing depth of XPS in the nanometer range and thus its surface sensitivity.In this Account, we focus on aqueous solutions relevant to the surface of oceans, aqueous aerosols, or cloudwater. We are interested in understanding solvation and acid dissociation at the interface, interfacial aspects of reactions with gas-phase reactants, and the interplay of ions with organic molecules at the interface. The strategy is to obtain a link between the molecular-level picture and macroscopic properties and reactivity in the atmospheric context.We show consistency between surface tension and XPS for a range of surface-active organic species as an important proof for interrogating an equilibrated liquid surface. Measurements with organic acids and amines offer important insight into the question of apparent acidity or basicity at the interface. Liquid microjet XPS has settled the debate of the surface enhancement of halide ions, shown using the example of bromide and its oxidation products. Despite the absence of a strong enhancement for the bromide ion, its rate of oxidation by ozone is surface catalyzed through the stabilization of the bromide ozonide intermediate at the interface. In another reaction system, the one between Fe
    Language English
    Publishing date 2022-12-06
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1483291-4
    ISSN 1520-4898 ; 0001-4842
    ISSN (online) 1520-4898
    ISSN 0001-4842
    DOI 10.1021/acs.accounts.2c00604
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Amplification of light within aerosol particles accelerates in-particle photochemistry.

    Corral Arroyo, Pablo / David, Grégory / Alpert, Peter A / Parmentier, Evelyne A / Ammann, Markus / Signorell, Ruth

    Science (New York, N.Y.)

    2022  Volume 376, Issue 6590, Page(s) 293–296

    Abstract: Optical confinement (OC) structures the optical field and amplifies light intensity inside atmospheric aerosol particles, with major consequences for sunlight-driven aerosol chemistry. Although theorized, the OC-induced spatial structuring has so far ... ...

    Abstract Optical confinement (OC) structures the optical field and amplifies light intensity inside atmospheric aerosol particles, with major consequences for sunlight-driven aerosol chemistry. Although theorized, the OC-induced spatial structuring has so far defied experimental observation. Here, x-ray spectromicroscopic imaging complemented by modeling provides direct evidence for OC-induced patterning inside photoactive particles. Single iron(III)-citrate particles were probed using the iron oxidation state as a photochemical marker. Based on these results, we predict an overall acceleration of photochemical reactions by a factor of two to three for most classes of atmospheric aerosol particles. Rotation of free aerosol particles and intraparticle molecular transport generally accelerate the photochemistry. Given the prevalence of OC effects, their influence on aerosol particle photochemistry should be considered by atmospheric models.
    Language English
    Publishing date 2022-04-14
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.abm7915
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article: Ordered Hydrogen Bonding Structure of Water Molecules Adsorbed on Silver Iodide Particles under Subsaturated Conditions

    Yang, Huanyu / Boucly, Anthony / Gabathuler, Jérôme Philippe / Bartels-Rausch, Thorsten / Artiglia, Luca / Ammann, Markus

    Journal of physical chemistry. 2021 May 21, v. 125, no. 21

    2021  

    Abstract: Silver iodide (AgI) is an efficient ice-nucleating material. This has been related to the close lattice match to hexagonal ice, which helps to nucleate ice crystals on its surface under supersaturated conditions. In turn, the structure of water molecules ...

    Abstract Silver iodide (AgI) is an efficient ice-nucleating material. This has been related to the close lattice match to hexagonal ice, which helps to nucleate ice crystals on its surface under supersaturated conditions. In turn, the structure of water molecules adsorbed on its surface, embodied in the coordination of hydrogen bonds, has not been addressed so far. We suspected that AgI may induce ice-like coordination among adsorbed water molecules already under subsaturated conditions. X-ray photoelectron spectroscopy was used to probe the structure and composition at the AgI surface. We determined the chemical properties of the surface, the thickness of adsorbed water, and the amount of contaminating carbon species. Auger electron yield near-edge X-ray absorption fine structure (NEXAFS) spectroscopy was used to assess the hydrogen bonding (HB) structure. The O K-edge NEXAFS spectra indicated that the HB structure of the adsorbed water on AgI under subsaturated conditions showed similarity to that of ice, which helps facilitate the stabilization of ice embryos at saturation. The approach used here opens up important perspectives for characterizing adsorbed water molecules on a wide variety of solids, which provides an important basis for understanding ice nucleation and other interfacial processes at the molecular level.
    Keywords X-ray absorption spectroscopy ; X-ray photoelectron spectroscopy ; carbon ; hydrogen ; ice ; ice nucleation ; iodides
    Language English
    Dates of publication 2021-0521
    Size p. 11628-11635.
    Publishing place American Chemical Society
    Document type Article
    Note NAL-AP-2-clean
    ISSN 1932-7455
    DOI 10.1021/acs.jpcc.1c01767
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  4. Article: Phase Behavior of Hydrocarbon-like Primary Organic Aerosol and Secondary Organic Aerosol Proxies Based on Their Elemental Oxygen-to-Carbon Ratio

    Mahrt, Fabian / Newman, Elli / Huang, Yuanzhou / Ammann, Markus / Bertram, Allan K.

    Environmental science & technology. 2021 Sept. 02, v. 55, no. 18

    2021  

    Abstract: A large fraction of atmospheric aerosols can be characterized as primary organic aerosol (POA) and secondary organic aerosol (SOA). Knowledge of the phase behavior, that is, the number and type of phases within internal POA + SOA mixtures, is crucial to ... ...

    Abstract A large fraction of atmospheric aerosols can be characterized as primary organic aerosol (POA) and secondary organic aerosol (SOA). Knowledge of the phase behavior, that is, the number and type of phases within internal POA + SOA mixtures, is crucial to predict their effect on climate and air quality. For example, if POA and SOA form a single phase, POA will enhance the formation of SOA by providing organic mass to absorb SOA precursors. Using microscopy, we studied the phase behavior of mixtures of SOA proxies and hydrocarbon-like POA proxies at relative humidity (RH) values of 90%, 45%, and below 5%. Internal mixtures of POA and SOA almost always formed two phases if the elemental oxygen-to-carbon ratio (O/C) of the POA was less than 0.11, which encompasses a large fraction of atmospheric hydrocarbon-like POA from fossil fuel combustion. SOA proxies mixed with POA proxies having 0.11 ≤ O/C ≤ 0.29 mostly resulted in particles with one liquid phase. However, two liquid phases were also observed, depending on the type of SOA and POA surrogates, and an increase in phase-separated particles was observed when increasing the RH in this O/C range. The results have implications for predicting atmospheric SOA formation and policy strategies to reduce SOA in urban environments.
    Keywords aerosols ; air quality ; climate ; fossil fuels ; fuel combustion ; issues and policy ; liquids ; microscopy ; relative humidity ; technology
    Language English
    Dates of publication 2021-0902
    Size p. 12202-12214.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1520-5851
    DOI 10.1021/acs.est.1c02697
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  5. Book: NO X-Konzentrationen im Nahbereich einer schweizerischen Autobahn und ihre Wirkungen auf Fichten

    Ammann, Markus / Brunold, Christian

    Schlußbericht des Forschungsauftrags Nr. 62/90, 2724.01

    (Eidgenössisches Verkehrs- und Energiewirtschaftsdepartement, Bundesamt für Strassenbau ; 350)

    1995  

    Title variant Concentrations de NO X près d'une autoroute en Suisse et ses effets sur les sapins
    Author's details Markus Ammann und Christian Brunold. Eidgenössisches Verkehrs- und Energiewirtschaftsdepartement, Bundesamt für Straßenbau (ASB)
    Series title Eidgenössisches Verkehrs- und Energiewirtschaftsdepartement, Bundesamt für Strassenbau ; 350
    Collection
    Keywords Schweiz ; Autobahn ; Stickstoffoxidemission ; Stickstoffoxidbelastung ; Fichtennadel ; Biomonitoring ; Stickstoffbelastung ; Fichte ; Stickstoffdioxidaufnahme
    Subject Biological monitoring ; Stickstoff ; Picea ; Bundesautobahn ; Reichsautobahn ; Autobahnen ; Fichte ; Stickoxidemission ; Stickoxide ; Stickstoffoxide
    Size 82 S. : graph. Darst.
    Publisher VSS
    Publishing place Zürich
    Publishing country Switzerland
    Document type Book
    HBZ-ID HT008947938
    Database Catalogue ZB MED Nutrition, Environment, Agriculture

    More links

    Kategorien

  6. Article ; Online: Comparison of Octreotide and Vasopressors as First-Line Treatment for Intraoperative Carcinoid Crisis.

    Ammann, Markus / Kinney, Michelle A O / Gudmundsdottir, Hallbera / Santol, Jonas / Thiels, Cornelius A / Warner, Susanne G / Truty, Mark J / Kendrick, Michael L / Smoot, Rory L / Anderson, Alexandra L / Halfdanarson, Thorvardur R / Nagorney, David M / Starlinger, Patrick P

    Annals of surgical oncology

    2024  Volume 31, Issue 6, Page(s) 3976–3977

    MeSH term(s) Humans ; Octreotide/therapeutic use ; Vasoconstrictor Agents/therapeutic use ; Carcinoid Tumor/surgery ; Carcinoid Tumor/drug therapy ; Carcinoid Tumor/pathology ; Intraoperative Complications ; Antineoplastic Agents, Hormonal/therapeutic use ; Malignant Carcinoid Syndrome/drug therapy ; Malignant Carcinoid Syndrome/surgery ; Prognosis
    Chemical Substances Octreotide (RWM8CCW8GP) ; Vasoconstrictor Agents ; Antineoplastic Agents, Hormonal
    Language English
    Publishing date 2024-04-15
    Publishing country United States
    Document type Comparative Study ; Editorial ; Letter
    ZDB-ID 1200469-8
    ISSN 1534-4681 ; 1068-9265
    ISSN (online) 1534-4681
    ISSN 1068-9265
    DOI 10.1245/s10434-024-15264-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Phase Behavior of Hydrocarbon-like Primary Organic Aerosol and Secondary Organic Aerosol Proxies Based on Their Elemental Oxygen-to-Carbon Ratio.

    Mahrt, Fabian / Newman, Elli / Huang, Yuanzhou / Ammann, Markus / Bertram, Allan K

    Environmental science & technology

    2021  Volume 55, Issue 18, Page(s) 12202–12214

    Abstract: A large fraction of atmospheric aerosols can be characterized as primary organic aerosol (POA) and secondary organic aerosol (SOA). Knowledge of the phase behavior, that is, the number and type of phases within internal POA + SOA mixtures, is crucial to ... ...

    Abstract A large fraction of atmospheric aerosols can be characterized as primary organic aerosol (POA) and secondary organic aerosol (SOA). Knowledge of the phase behavior, that is, the number and type of phases within internal POA + SOA mixtures, is crucial to predict their effect on climate and air quality. For example, if POA and SOA form a single phase, POA will enhance the formation of SOA by providing organic mass to absorb SOA precursors. Using microscopy, we studied the phase behavior of mixtures of SOA proxies and hydrocarbon-like POA proxies at relative humidity (RH) values of 90%, 45%, and below 5%. Internal mixtures of POA and SOA almost always formed two phases if the elemental oxygen-to-carbon ratio (O/C) of the POA was less than 0.11, which encompasses a large fraction of atmospheric hydrocarbon-like POA from fossil fuel combustion. SOA proxies mixed with POA proxies having 0.11 ≤ O/C ≤ 0.29 mostly resulted in particles with one liquid phase. However, two liquid phases were also observed, depending on the type of SOA and POA surrogates, and an increase in phase-separated particles was observed when increasing the RH in this O/C range. The results have implications for predicting atmospheric SOA formation and policy strategies to reduce SOA in urban environments.
    MeSH term(s) Aerosols/analysis ; Air Pollutants/analysis ; Carbon ; Hydrocarbons ; Oxygen
    Chemical Substances Aerosols ; Air Pollutants ; Hydrocarbons ; Carbon (7440-44-0) ; Oxygen (S88TT14065)
    Language English
    Publishing date 2021-09-02
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1520-5851
    ISSN (online) 1520-5851
    DOI 10.1021/acs.est.1c02697
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Microphysics of the aqueous bulk counters the water activity driven rate acceleration of bromide oxidation by ozone from 289-245 K.

    Edebeli, Jacinta / Ammann, Markus / Bartels-Rausch, Thorsten

    Environmental science. Processes & impacts

    2018  Volume 21, Issue 1, Page(s) 63–73

    Abstract: The reaction of ozone with bromide is an initiation process in bromine activation resulting in the formation of reactive bromine species with impacts on the fate of compounds in the lower atmosphere. Environmental halide sources often contain organics, ... ...

    Abstract The reaction of ozone with bromide is an initiation process in bromine activation resulting in the formation of reactive bromine species with impacts on the fate of compounds in the lower atmosphere. Environmental halide sources often contain organics, which are known to influence aqueous bulk reactivity. Here, we present a study investigating the temperature dependence of bromide oxidation by ozone using a coated wall flow tube reactor coated with an aqueous mixture of citric acid, as a proxy for oxidized secondary organic matter, and sodium bromide. Using the resistor model formulation, we quantify changes in the properties of the aqueous bulk relevant for the observed reactivity. The reactive uptake coefficient decreased from 2 × 10-6 at 289 K to 0.5 × 10-6 at 245 K. Our analysis indicates that the humidity-driven increase in concentration with a corresponding increase in the pseudo-first order reaction rate was countered by the colligative change in ozone solubility and the effect of the organic fraction via increased viscosity and decreased diffusivity of ozone as the temperature decreased. From our parameterization, we provide an extension of the temperature dependence of the reaction rate coefficients driving the oxidation of bromide, and assess the temperature-dependent salting effects of citric acid on ozone solubility. This study shows the effects of the organic species at relatively mild temperatures, between the freezing point and eutectic temperature of sea as is typical for the Earth's cryosphere. Thus, this study may be relevant for atmospheric models at different scales describing halogen activation in the marine boundary layer or free troposphere including matrices such as sea-spray aerosol and brine in sea ice, snow, and around mid-latitude salt lakes.
    MeSH term(s) Atmosphere/chemistry ; Bromides/chemistry ; Bromine/chemistry ; Citric Acid/chemistry ; Organic Chemicals ; Oxidation-Reduction ; Ozone/analysis ; Ozone/chemistry ; Salts ; Sodium Compounds/chemistry ; Solubility ; Temperature ; Viscosity
    Chemical Substances Bromides ; Organic Chemicals ; Salts ; Sodium Compounds ; brine ; Citric Acid (2968PHW8QP) ; Ozone (66H7ZZK23N) ; sodium bromide (LC1V549NOM) ; Bromine (SBV4XY874G)
    Language English
    Publishing date 2018-12-07
    Publishing country England
    Document type Journal Article
    ZDB-ID 2703814-2
    ISSN 2050-7895 ; 2050-7887
    ISSN (online) 2050-7895
    ISSN 2050-7887
    DOI 10.1039/c8em00417j
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Reply to "Comment on 'Liquid-Gas Interface of Iron Aqueous Solutions and Fenton Reagents'".

    Gladich, Ivan / Chen, Shuzhen / Yang, Huanyu / Boucly, Anthony / Winter, Bernd / van Bokhoven, Jeroen A / Ammann, Markus / Artiglia, Luca

    The journal of physical chemistry letters

    2022  Volume 13, Issue 29, Page(s) 6681–6682

    Abstract: A Viewpoint regarding our recently published Letter in this Journal (Gladich et al. ...

    Abstract A Viewpoint regarding our recently published Letter in this Journal (Gladich et al.
    Language English
    Publishing date 2022-07-18
    Publishing country United States
    Document type Journal Article
    ISSN 1948-7185
    ISSN (online) 1948-7185
    DOI 10.1021/acs.jpclett.2c01391
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Liquid-Gas Interface of Iron Aqueous Solutions and Fenton Reagents.

    Gladich, Ivan / Chen, Shuzhen / Yang, Huanyu / Boucly, Anthony / Winter, Bernd / van Bokhoven, Jeroen A / Ammann, Markus / Artiglia, Luca

    The journal of physical chemistry letters

    2022  Volume 13, Issue 13, Page(s) 2994–3001

    Abstract: Fenton chemistry, involving the reaction between ... ...

    Abstract Fenton chemistry, involving the reaction between Fe
    Language English
    Publishing date 2022-03-28
    Publishing country United States
    Document type Journal Article
    ISSN 1948-7185
    ISSN (online) 1948-7185
    DOI 10.1021/acs.jpclett.2c00380
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top