| 1. |
- Mistretta, Francesco A., et al.
(författare)
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DFL23448, A Novel Transient Receptor Potential Melastin 8-Selective Ion Channel Antagonist, Modifies Bladder Function and Reduces Bladder Overactivity in Awake Rats
- 2016
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Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS. - 0022-3565 .- 1521-0103. ; 356:1, s. 200-211
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Tidskriftsartikel (refereegranskat)abstract
- The transient receptor potential melastin 8 ion channel (TRPM8) is implicated in bladder sensing but limited information on TRPM8 antagonists in bladder overactivity is available. This study characterizes a new TRPM8-selective antagonist (DFL23448 [5-(2-ethyl-2H-tetrazol-5-yl)-2-(3-fluorophenyl)-1,3-thiazol-4-ol]) and evaluates it in cold-induced behavioral tests and tests on bladder function and experimental bladder overactivity in vivo in rats. DFL23448 displayed IC50 values of 10 and 21 nM in hTRPM8 human embryonic kidney 293 cells activated by Cooling Agent 10 or cold, but it had limited activity (IC50 > 10 mu M) at transient receptor potential vanilloids TRPV1, TRPA1, or TRPV4 or at various G protein-coupled receptors. In rats, DFL23448 administered intravenously or orally had a half-life of 37 minutes or 4.9 hours, respectively. DLF23448 (10 mg/kg i.v.) reduced icilin-induced "wet dog-like" shakes in rats. Intravesical DFL23448 (10 mg/l), but not vehicle, increased micturition intervals, micturition volume, and bladder capacity. During bladder overactivity by intravesical prostaglandin E-2 (PGE(2)), vehicle controls exhibited reductions in micturition intervals, micturition volumes, and bladder capacity by 37%-39%, whereas the same parameters only decreased by 12%-15% (P < 0.05-0.01 versus vehicle) in DFL23448-treated rats. In vehicle-treated rats, but not in DFL23448-treated rats, intravesical PGE(2) increased bladder pressures. Intravenous DFL23448 at 10 mg/kg, but not 1 mg/kg DFL23448 or vehicle, increased micturition intervals, micturition volumes, and bladder capacity. During bladder overactivity by intravesical PGE(2), micturition intervals, micturition volumes, and bladder capacity decreased in vehicle- and 1 mg/kg DFL23448-treated rats, but not in 10 mg/kg DFL23448-treated rats. Bladder pressures increased less in rats treated with DFL23448 10 mg/kg than in vehicle-or 1 mg/kg DFL23448-treated rats. DFL23448 (10 mg/kg i.v.), but not vehicle, prevented cold stress-induced bladder overactivity. Our results support a role for bladder TRPM8-mediated signals in experimental bladder overactivity.
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| 2. |
- Mistretta, Francesco A, et al.
(författare)
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DFL23448, a novel TRPM8-selective ion channel antagonist, modifies bladder function and reduces bladder overactivity in awake rats.
- 2016
-
Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0103. ; 356:1, s. 200-211
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Tidskriftsartikel (refereegranskat)abstract
- The transient receptor potential (TRP) melastin 8 ion channel (TRPM8) is implicated in bladder sensing but limited information on TRPM8 antagonists in bladder overactivity (BO) is available. This study characterizes a new TRPM8-selective antagonist (DFL23448) and evaluates it in cold-induced behavioral tests and on bladder function and experimental BO in vivo in rats. DFL23448 displayed IC50 values of 10 and 21nM in hTRPM8 HEK-293 cells activated by Cooling Agent 10 or cold, but had limited activity (IC50 > 10μM) at TRPV1, TRPA1, TRPV4, or at various G-protein-coupled receptors. In rats, DFL23448 had a half-life of 37 minutes (intravenous; i.v.) or 4.9 hours (oral). DLF23448 (10mg/kg, i.v) reduced icilin-induced wet-dog shakes in rats. Intravesical (i.ves.) DFL23448 (10mg/L) but not vehicle increased micturition intervals (MI), micturition volumes (MV) and bladder capacity (BC). During BO by i.ves. PGE2, vehicle controls exhibited reductions of MI, MV and BC by 37-39%, whereas the same parameters only decreased by 12-15% (p<0.05-0.01 vs. vehicle) in DFL23448-treated rats. In vehicle-treated rats but not in DFL23448-treated rats, i.ves. PGE2 increased bladder pressures. Intravenous DFL23448 at 10mg/kg, but not 1mg/kg DFL23448 or vehicle, increased MI, MV, and BC. During BO by i.ves. PGE2, MI, MV, and BC decreased in vehicle- and in DFL23448 1mg/kg-treated rats, but not in DFL23448 10mg/kg-treated rats. Bladder pressures increased less in rats treated with DFL23448 10mg/kg than in vehicle- or DFL23448 1mg/kg- treated rats. DFL23448 (10mg/kg, i.v.), but not vehicle, prevented cold-stress BO. Our results support a role for bladder TRPM8-mediated signals in experimental BO.
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| 3. |
- Diller, Katharina, et al.
(författare)
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Polyphenylsilole multilayers - an insight from X-ray electron spectroscopy and density functional theory
- 2015
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 17:46, s. 31117-31124
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Tidskriftsartikel (refereegranskat)abstract
- We present a combined investigation by means of X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy of condensed multilayers of two polyphenylsiloles, namely hexaphenylsilole (HPS) and tetraphenylsilole (TPS). Both compounds exhibit very similar spectroscopic signatures, whose interpretation is aided by density functional theory (DFT) calculations. High-resolution XPS spectra of the Si 2p and C 1s core levels of these multilayers indicate a positively charged silicon ion flanked by two negatively charged adjacent carbon atoms in the silole core of both molecules. This result is corroborated quantitatively by DFT calculations on isolated HPS (TPS) molecules, which show a natural bond orbital partial charge of + 1.67 e (+1.58 e) on the silicon and -0.34 e (-0.58 e) on the two neighbouring carbon atoms in the silole ring. These charges are conserved in direct contact with a Cu(111) substrate for films of submonolayer coverage, as evidenced by the Si 2p XPS data. The C K-edge NEXAFS spectra of HPS and TPS multilayers exhibit distinct and differing features. Their main characteristics reappear in the simulated spectra and are assigned to the different inequivalent carbon species in the molecule. The angle-dependent measurements hardly reveal any dichroism, i.e., the molecular p-systems are not uniformly oriented parallel or perpendicular with respect to the surface. Changes in the growth conditions of TPS, i.e., a reduction of the substrate temperature from 240 K to 80 K during deposition, lead to a broadening of both XPS and NEXAFS signatures, as well as an upward shift of the Si 2p and C 1s binding energies, indicative of a less ordered growth mode at low temperature.
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| 4. |
- Fritton, Massimo, et al.
(författare)
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The Role of Kinetics versus Thermodynamics in Surface-Assisted Ullmann Coupling on Gold and Silver Surfaces
- 2019
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Ingår i: Journal of the American Chemical Society. - : AMER CHEMICAL SOC. - 0002-7863 .- 1520-5126. ; 141:12, s. 4824-4832
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Tidskriftsartikel (refereegranskat)abstract
- Surface-assisted Ullmann coupling is the workhorse of on-surface synthesis. Despite its obvious relevance, many fundamental and mechanistic aspects remain elusive. To shed light on individual reaction steps and their progression with temperature, temperature-programmed X-ray photoelectron spectroscopy (TP-XPS) experiments are performed for a prototypical model system. The activation of the coupling by initial dehalogenation is tracked by monitoring Br 3d core levels, whereas the C 1s signature is used to follow the emergence of metastable organometallic intermediates and their conversion to the final covalent products upon heating in real time. The employed 1,3,5-tris(4-bromophenyl)benzene precursor is comparatively studied on Ag(111) versus Au(111), whereby intermolecular bonds and network topologies are additionally characterized by scanning tunneling microscopy (STM). Besides the well-comprehended differences in activation temperatures for debromination, the thermal progression shows marked differences between the two surfaces. Debromination proceeds rapidly on Ag(111), but is relatively gradual on Au(111). While on Ag(111) debromination is well explained by first-order reaction kinetics, thermodynamics prevail on Au(111), underpinned by a close agreement between experimentally deduced and density functional theory (DFT) calculated reaction enthalpies. Thermodynamically controlled debromination on Au(111) over a large temperature range implies an unexpectedly long lifetime of surface-stabilized radicals prior to covalent coupling, as corroborated by TP-XPS of C is core levels. These insights are anticipated to play an important role regarding our ability to rationally synthesize atomically precise low-dimensional covalent nanostructures on surfaces.
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| 5. |
- Hohn, Nuri, et al.
(författare)
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Amphiphilic diblock copolymer-mediated structure control in nanoporous germanium-based thin films
- 2019
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Ingår i: Nanoscale. - : ROYAL SOC CHEMISTRY. - 2040-3364 .- 2040-3372. ; 11:4, s. 2048-2055
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Tidskriftsartikel (refereegranskat)abstract
- Fabrication of porous, foam-like germanium-based (Ge-based) nanostructures is achieved with the use of the amphiphilic diblock copolymer polystyrene-b-polyethylene oxide as structure directing agent. Basic concepts of block copolymer assisted sol-gel synthesis are successfully realized based on the [Ge-9](4-) Zintl clusters as a precursor for Ge-based thin films. Material/elemental composition and crystalline Ge-based phases are investigated via X-ray photoelectron spectroscopy and X-ray diffraction measurements, respectively. Poor-good solvent pair induced phase separation leads to pore sizes in the Ge-based films up to 40 nm, which can be tuned through a change of the molar mixing ratio between polymer template and precursor as proven by grazing incidence small angle X-ray scattering and scanning electron microscopy.
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| 6. |
- Jiang, Xinyu, et al.
(författare)
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Internal nanoscale architecture and charge carrier dynamics of wide bandgap non-fullerene bulk heterojunction active layers in organic solar cells
- 2020
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 8:44, s. 23628-23636
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Tidskriftsartikel (refereegranskat)abstract
- Bulk heterojunction (BHJ) organic solar cells have gained increasing attention in the past few years. In this work, active layers of a wide-bandgap polymer donor with benzodithiophene units PBDB-T-2F and a non-fullerene small molecule acceptor IT-M are assembled into photovoltaic devices with different amounts of solvent additive 1,8-diiodooctane (DIO). The influence of DIO on the nanoscale film morphology and crystalline structure as well as the charge carrier dynamics of the active layers are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS), grazing-incidence wide-angle X-ray scattering (GIWAXS), X-ray reflectivity (XRR), UV-visible (UV-vis) absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), time-resolved photoluminescence (TRPL) and space charge limited current measurements, which are correlated with the corresponding performance of the solar cells. At 0.5 vol% DIO addition, the wide-bandgap non-fullerene organic solar cells show the best performance due to high open-circuit voltage and short-circuit current resulting from an improved charge carrier management due to the optimal inner nanoscale morphology of the active layers in terms of surface enrichment, crystallinity and crystalline orientation.
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| 7. |
- Paintner, Tobias, et al.
(författare)
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Quantum Tunneling Mediated Interfacial Synthesis of a Benzofuran Derivative
- 2019
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 58:33, s. 11285-11290
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Tidskriftsartikel (refereegranskat)abstract
- Reaction pathways involving quantum tunneling of protons are fundamental to chemistry and biology. They are responsible for essential aspects of interstellar synthesis, the degradation and isomerization of compounds, enzymatic activity, and protein dynamics. On-surface conditions have been demonstrated to open alternative routes for organic synthesis, often with intricate transformations not accessible in solution. Here, we investigate a hydroalkoxylation reaction of a molecular species adsorbed on a Ag(111) surface by scanning tunneling microscopy complemented by X-ray electron spectroscopy and density functional theory. The closure of the furan ring proceeds at low temperature (down to 150 K) and without detectable side reactions. We unravel a proton-tunneling-mediated pathway theoretically and confirm experimentally its dominant contribution through the kinetic isotope effect with the deuterated derivative.
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| 8. |
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| 9. |
- Yang, Biao, et al.
(författare)
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Abiotic Formation of an Amide Bond via Surface-Supported Direct Carboxyl-Amine Coupling
- 2022
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 61:5
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Tidskriftsartikel (refereegranskat)abstract
- Amide bond formation is one of the most important reactions in biochemistry, notably being of crucial importance for the origin of life. Herein, we combine scanning tunneling microscopy and X-ray photoelectron spectroscopy studies to provide evidence for thermally activated abiotic formation of amide bonds between adsorbed precursors through direct carboxyl-amine coupling under ultrahigh-vacuum conditions by means of on-surface synthesis. Complementary insights from temperature-programmed desorption measurements and density functional theory calculations reveal the competition between cross-coupling amide formation and decarboxylation reactions on the Au(111) surface. Furthermore, we demonstrate the critical influence of the employed metal support: whereas on Au(111) the coupling readily occurs, different reaction scenarios prevail on Ag(111) and Cu(111). The systematic experiments signal that archetypical bio-related molecules can be abiotically synthesized in clean environments without water or oxygen.
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| 10. |
- Zhang, Yi-Qi, et al.
(författare)
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Homo-coupling of terminal alkynes on a noble metal surface
- 2012
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- The covalent linking of acetylenes presents an important route for the fabrication of novel carbon-based scaffolds and two-dimensional materials distinct from graphene. To date few attempts have been reported to implement this strategy at well-defined interfaces or monolayer templates. Here we demonstrate through real space direct visualization and manipulation in combination with X-ray photoelectron spectroscopy and density functional theory calculations the Ag surface-mediated terminal alkyne Csp−H bond activation and concomitant homo-coupling in a process formally reminiscent of the classical Glaser–Hay type reaction. The alkyne homo-coupling takes place on the Ag(111) noble metal surface in ultrahigh vacuum under soft conditions in the absence of conventionally used transition metal catalysts and with volatile H2 as the only by-product. With the employed multitopic ethynyl species, we demonstrate a hierarchic reaction pathway that affords discrete compounds or polymeric networks featuring a conjugated backbone. This presents a new approach towards on-surface covalent chemistry and the realization of two-dimensional carbon-rich or all-carbon polymers.
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