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Publications (10 of 22) Show all publications
Ma, H., Gao, T., Jakobsson, J. E. T., Weman, H. M., Xu, B., Larhammar, D. & Lagerström, M. C. (2020). The Neuropeptide Y Y-2 Receptor Is Coexpressed with Nppb in Primary Afferent Neurons and Y-2 Activation Reduces Histaminergic and IL-31-Induced Itch. Journal of Pharmacology and Experimental Therapeutics, 372(1), 73-82
Open this publication in new window or tab >>The Neuropeptide Y Y-2 Receptor Is Coexpressed with Nppb in Primary Afferent Neurons and Y-2 Activation Reduces Histaminergic and IL-31-Induced Itch
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2020 (English)In: Journal of Pharmacology and Experimental Therapeutics, ISSN 0022-3565, E-ISSN 1521-0103, Vol. 372, no 1, p. 73-82Article in journal (Refereed) Published
Abstract [en]

Itch stimuli are detected by specialized primary afferents that convey the signal to the spinal cord, but how itch transmission is regulated is still not completely known. Here, we investigated the roles of the neuropeptide Y (NPY)/Y-2 receptor system on scratch behavior. The inhibitory Y-2 receptor is expressed on mouse primary afferents, and intrathecal administration of the Y-2 agonist peptide YY (PYY)(3-36) reduced scratch episode frequency and duration induced by compound 48/80, an effect that could be reversed by intrathecal preadministration of the Y-2 antagonist BIIE0246. Also, scratch episode duration induced by histamine could be reduced by PYY3-36. In contrast, scratch behavior induced by alpha-methyl-5HT, protease-activated receptor-2-activating peptide SLIGRL, chloroquine, topical dust mite extract, or mechanical itch induced by von Frey filaments was unaffected by stimulation of Y2. Primary afferent neurons expressing the Npy2r gene were found to coexpress itch-associated markers such as natriuretic peptide precursor b, oncostatin M receptor, and interleukin (IL) 31 receptor A. Accordingly, intrathecal PYY3-36 reduced the scratch behavior induced by IL-31. Our findings imply that the NPY/Y-2 system reduces histaminergic and IL-31-associated itch through presynaptic inhibition of a subpopulation of itch-associated primary afferents. SIGNIFICANCE STATEMENT The spinal neuropeptide Y system dampens scratching behavior induced by histaminergic compounds and interleukin 31, a cytokine involved in atopic dermatitis, through interactions with the Y-2 receptor. The Y-2 receptor is expressed by primary afferent neurons that are rich in itch-associated neurotransmitters and receptors such as somatostatin, natriuretic peptide precursor b, and interleukin 31 receptors.

Place, publisher, year, edition, pages
AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS, 2020
National Category
Pharmacology and Toxicology
Identifiers
urn:nbn:se:uu:diva-404698 (URN)10.1124/jpet.119.262584 (DOI)000507945200008 ()31771994 (PubMedID)
Funder
Swedish Research CouncilThe Swedish Brain FoundationRagnar Söderbergs stiftelseStiftelsen Olle Engkvist Byggmästare
Available from: 2020-02-27 Created: 2020-02-27 Last updated: 2020-02-27Bibliographically approved
Huang, J., Xu, B., Tian, L., Pati, P. B., Etman, A. S., Sun, J., . . . Tian, H. (2019). A heavy metal-free CuInS2 quantum dot sensitized NiO photocathode with a Re molecular catalyst for photoelectrochemical CO2 reduction. Chemical Communications, 55(55), 7918-7921
Open this publication in new window or tab >>A heavy metal-free CuInS2 quantum dot sensitized NiO photocathode with a Re molecular catalyst for photoelectrochemical CO2 reduction
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2019 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 55, no 55, p. 7918-7921Article in journal (Refereed) Published
Abstract [en]

Heavy metal-free CuInS2 quantum dots (QDs) were employed as a photosensitizer on a NiO photocathode to drive an immobilized molecular Re catalyst for photoelectrochemical CO2 reduction for the first time. A photocurrent of 25 mu A cm(-2) at -0.87 V vs. NHE was obtained, providing a faradaic efficiency of 32% for CO production.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-390783 (URN)10.1039/c9cc04222a (DOI)000474306200003 ()31215919 (PubMedID)
Funder
Swedish Energy Agency, 11674-8Göran Gustafsson Foundation for Research in Natural Sciences and MedicineStiftelsen Olle Engkvist Byggmästare
Available from: 2019-08-16 Created: 2019-08-16 Last updated: 2019-08-16Bibliographically approved
Xu, B., Wrede, S., Curtze, A., Tian, L., Pati, P. B., Kloo, L., . . . Tian, H. (2019). An Indacenodithieno[3,2-b]thiophene-Based Organic Dye for Solid-State p-Type Dye-Sensitized Solar Cells. ChemSusChem, 12(14), 3243-3248
Open this publication in new window or tab >>An Indacenodithieno[3,2-b]thiophene-Based Organic Dye for Solid-State p-Type Dye-Sensitized Solar Cells
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2019 (English)In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 12, no 14, p. 3243-3248Article in journal (Refereed) Published
Abstract [en]

An indacenodithieno[3,2-b]thiophene (IDTT) unit is used as a linker moiety to design a new p-type dye-TIP-for solid-state p-type dye-sensitized solar cells. Solar cells based on the TIP dye offered an efficiency of 0.18 % with an open-circuit photovoltage of 550 mV and a short-circuit photocurrent density of 0.86 mA cm(-2), which is better than those of two reference dyes, PB6 and BH4. Charge lifetime experiments reveal that the IDTT linker-based TIP dye significantly suppresses charge recombination losses in the devices.

Keywords
dye-sensitized solar cells, energy materials, p-type dye, S heterocycles, solid state
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-393128 (URN)10.1002/cssc.201901102 (DOI)000478633900003 ()31144448 (PubMedID)
Funder
Swedish Energy Agency, 43599-1Stiftelsen Olle Engkvist Byggmästare
Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-09-24Bibliographically approved
Leandri, V., Raffaella, A., Pizzichetti, P., Xu, B., Franchi, D., Zhang, W., . . . Gardner, J. M. (2019). Exploring the Optical and Electrochemical Properties of Homoleptic versus Heteroleptic Diimine Copper(I) Complexes. Inorganic Chemistry, 58(18), 12167-12177
Open this publication in new window or tab >>Exploring the Optical and Electrochemical Properties of Homoleptic versus Heteroleptic Diimine Copper(I) Complexes
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2019 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 58, no 18, p. 12167-12177Article in journal (Refereed) Published
Abstract [en]

Due to ligand scrambling, the synthesis and investigation of the properties of heteroleptic Cu(I) complexes can be a challenging task. In this work, we have studied the optical and electrochemical properties of a series of homoleptic complexes, such as [Cu(dbda)(2)](+), [Cu(dmp)(2)](+), [Cu(Br-dmp)(2)](+), [Cu(bcp)(2)](+), [Cu(dsbtmp)(2)](+), [Cu(biq)(2)](+), and [Cu(dap)(2)](+) in solution, and those of their heteroleptics [Cu(dbda)(dmp)](+), [Cu(dbda)(Br-dmp)](+), [Cu(dbda)(bcp)](+), [Cu(dbda)(dsbtmp))(+), [Cu(dbda)(biq)](+), [Cu(dbda)(dap)](+) adsorbed on the surface of anatase TiO2 (dbda = 6,6'-dimethyl-2,2'-bipyridine-4,4'-dibenzoic acid; dmp = 2,9-dimethyl-1,10-phenanthroline; Br-dmp = 5-bromo 2,9-dimethyl-1,10-phenanthroline; bcp = bathocuproine or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; dsbtmp = 2,9-di(sec-butyl)-3,4,7,8-tetramethyl-1,10-phenanthroline; biq = 2,2'-biquinoline; dap = 2,9-dianisyl-1,10-phenanthroline). We show that the maximum absorption wavelengths of the heteroleptic complexes on TiO2 can be reasonably predicted from those of the homoleptic complexes in solution through a simple linear relation, whereas the prediction of their redox properties is less trivial. In the latter case, two different linear patterns emerge: one including the ligands bcp, biq, and dap and another one including the ligands dmp, Br-dmp, and dsbtmp. We offer an interpretation of the data based on the chemical structure of the ligands. On one hand, ligands bcp, biq, and dap possess a more extended pi-conjugated system, which gives a more prominent contribution to the overall redox properties of the ligand dbda. On the other hand, the ligands dmp, Br-dmp, and dsbtmp are all phenanthroline-based containing alkyl substituents and contribute less than dbda to the overall redox properties.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-395309 (URN)10.1021/acs.inorgchem.9b01487 (DOI)000486565600035 ()31483631 (PubMedID)
Funder
Swedish Research CouncilSwedish Energy AgencyStandUp
Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-10-18Bibliographically approved
Shebanits, K., Vasile, S., Xu, B., Gutiérrez-de-Terán, H. & Larhammar, D. (2019). Functional characterization in vitro of twelve naturally occurring variants of the human pancreatic polypeptide receptor NPY4R. Neuropeptides, 76, Article ID 101933.
Open this publication in new window or tab >>Functional characterization in vitro of twelve naturally occurring variants of the human pancreatic polypeptide receptor NPY4R
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2019 (English)In: Neuropeptides, ISSN 0143-4179, E-ISSN 1532-2785, Vol. 76, article id 101933Article in journal (Refereed) Published
Abstract [en]

Obesity has become a global health problem and therefore understanding of the mechanisms regulating hunger and satiety is of utmost importance for the development of new treatment strategies. The Y4 receptor, encoded by the NPY4R gene, and its ligand pancreatic polypeptide (PP) have been reported to mediate a satiety signal. Multiple genetic studies have reported an association between NPY4R copy number and body weight. The gene also displays several SNP variants, many of which lead to amino acid differences, making it interesting to study. We have investigated the functional properties of 12 naturally occurring amino acid sequence variants of the Y4 and interpret the results in relation to sequence conservation and our structural model of the human Y4 receptor protein. Three receptor variants, Cys201ECL2Tyr, Val2716.41Leu and Asn3187.49Asp, were found to completely lose functional response, measured as inositol phosphate turnover, while retaining membrane expression. They display high sequence conservation and have important roles in the receptor structure. For two receptor variants the potency of PP was significantly decreased, Cys34NTSer (EC50 = 2.9 nM, p < .001) and Val1353.46Met (EC50 = 3.0 nM, p < .01), compared to wild-type Y4 (EC50 = 0.68 nM). Cys34 forms a disulphide bond with Cys298, linking the N-terminal part to ECL3. The Val1353.46Met variant has an amino acid replacement located in the TM3 helix, one helix turn above the highly conserved ERH motif. This position has influence on the network of residues involved in receptor activation and subsequent inactivation. Sequence conservation and the structural model are consistent with these results. The remaining seven positions had no significant effect on the receptor's functional response compared to wild-type Y4. These positions display more variation during evolution. Understanding of the interactions between the Y4 receptor and its native PP agonist and the effects of amino acid variation on its functional response will hopefully lead to future therapeutic possibilities.

Keywords
Y4, SNP, Mutagenesis, Functional pharmacology, Structural modelling
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:uu:diva-356572 (URN)10.1016/j.npep.2019.05.004 (DOI)000482249700004 ()31230758 (PubMedID)
Funder
Swedish Research Council, K2013-55 x -22189-01-2The Swedish Brain Foundation, F02016-0217
Available from: 2018-08-01 Created: 2018-08-01 Last updated: 2019-12-06Bibliographically approved
Xu, B., Tian, L., Etman, A. S., Sun, J. & Tian, H. (2019). Solution-processed nanoporous NiO-dye-ZnO photocathodes: Toward efficient and stable solid-state p-type dye-sensitized solar cells and dye-sensitized photoelectrosynthesis cells. Nano Energy, 55, 59-64
Open this publication in new window or tab >>Solution-processed nanoporous NiO-dye-ZnO photocathodes: Toward efficient and stable solid-state p-type dye-sensitized solar cells and dye-sensitized photoelectrosynthesis cells
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2019 (English)In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 55, p. 59-64Article in journal (Refereed) Published
Abstract [en]

A solution-processed NiO-dye-ZnO photocathode was developed for applications in both solid-state p-type dye-sensitized solar cells (p-ssDSCs) and p-type dye-sensitized photoelectrosynthesis cells (p-DSPECs). In p-ssDSCs, the solar cell using ZnO as electron transport material showed a short circuit current, up to 680 mu A cm(-2), which is 60-fold larger than that previously reported device using TiO2 as electron transport material with similar architecture. In the p-DSPECs, a remarkable photocurrent of 100 mu A cm(-2) was achieved in a pH = 5.0 acetate buffer solution under a bias potential at 0.05 V vs RHE with platinum as the proton reduction catalyst. A Faradaic efficiency approaching 100% for the H-2 evolution reaction was obtained after photoelectrolysis for 9 h. Importantly, the solution-processed NiO-dye-ZnO photocathode exhibited excellent long-term stability in both p-ssDSCs and p-DSPECs. To the best of our knowledge, this is the first study where a solution-processable, nanoporous NiO-dye-ZnO photocathode is used for both p-ssDSCs and p-DSPECs having both excellent device performance and stability.

Keywords
Dye-sensitized photocathode, P-type, Solution-processed, Solid-state, Solar cell, Solar fuel
National Category
Materials Chemistry Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-374114 (URN)10.1016/j.nanoen.2018.10.054 (DOI)000454636200007 ()
Funder
Swedish Energy Agency, 43599-1Swedish Energy Agency, 11674-8
Note

Bo Xu and Lei Tian contributed equally to this work.

Available from: 2019-01-23 Created: 2019-01-23 Last updated: 2020-01-15Bibliographically approved
Zhang, J., Daniel, Q., Zhang, T., Wen, X., Xu, B., Sun, L., . . . Cheng, Y.-B. (2018). Chemical Dopant Engineering in Hole Transport Layers for Efficient Perovskite Solar Cells: Insight into the Interfacial Recombination. ACS Nano, 12(10), 10452-10462
Open this publication in new window or tab >>Chemical Dopant Engineering in Hole Transport Layers for Efficient Perovskite Solar Cells: Insight into the Interfacial Recombination
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2018 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 10, p. 10452-10462Article in journal (Refereed) Published
Abstract [en]

Chemical doping of organic semiconductors has been recognized as an effective way to enhance the electrical conductivity. In perovskite solar cells (PSCs), various types of dopants have been developed for organic hole transport materials (HTMs); however, the knowledge of the basic requirements for being efficient dopants as well as the comprehensive roles of the dopants in PSCs has not been clearly revealed. Here, three copper-based complexes with controlled redox activities are applied as dopants in PSCs, and it is found that the oxidative reactivity of dopants presents substantial impacts on conductivity, charge dynamics, and solar cell performance. A significant improvement of open- circuit voltage (V-oc) by more than 100 mV and an increase of power conversion efficiency from 13.2 to 19.3% have been achieved by tuning the doping level of the HTM. The observed large variation of V-oc for three dopants reveals their different recombination kinetics at the perovskite/HTM interfaces and suggests a model of an interfacial recombination mechanism. We also suggest that the dopants in HTMs can also affect the charge recombination kinetics as well as the solar cell performance. Based on these findings, a strategy is proposed to physically passivate the electron- hole recombination by inserting an ultrathin Al2O3 insulating layer between the perovskite and the HTM. This strategy contributes a significant enhancement of the power conversion efficiency and environmental stability, indicating that dopant engineering is one crucial way to further improve the performance of PSCs.

Keywords
chemical dopants, hole transport materials, perovskite solar cells, interfacial recombination, passivation, Al2O3
National Category
Energy Engineering
Identifiers
urn:nbn:se:uu:diva-369760 (URN)10.1021/acsnano.8b06062 (DOI)000448751800083 ()30207694 (PubMedID)
Funder
Swedish Energy AgencySwedish Foundation for Strategic Research
Available from: 2018-12-17 Created: 2018-12-17 Last updated: 2018-12-17Bibliographically approved
Huang, J., Gilbert Gatty, M., Xu, B., Pati, P. B., Etman, A. S., Tian, L., . . . Tian, H. (2018). Covalently linking CuInS2 quantum dots with a Re catalyst by click reaction for photocatalytic CO2 reduction. Dalton Transactions, 47(31), 10775-10783
Open this publication in new window or tab >>Covalently linking CuInS2 quantum dots with a Re catalyst by click reaction for photocatalytic CO2 reduction
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2018 (English)In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 47, no 31, p. 10775-10783Article in journal (Refereed) Published
Abstract [en]

Covalently linking photosensitizers and catalysts in an inorganic-organic hybrid photocatalytic system is beneficial for efficient electron transfer between these components. However, general and straightforward methods to covalently attach molecular catalysts on the surface of inorganic semiconductors are rare. In this work, a classic rhenium bipyridine complex (Re catalyst) has been successfully covalently linked to the low toxicity CuInS2 quantum dots (QDs) by click reaction for photocatalytic CO2 reduction. Covalent bonding between the CuInS2 QDs and the Re catalyst in the QD-Re hybrid system is confirmed by UV-visible absorption spectroscopy, Fourier-transform infrared spectroscopy and energy-dispersive X-ray measurements. Time-correlated single photon counting and ultrafast time-resolved infrared spectroscopy provide evidence for rapid photo-induced electron transfer from the QDs to the Re catalyst. Upon photo-excitation of the QDs, the singly reduced Re catalyst is formed within 300 fs. Notably, the amount of reduced Re in the linked hybrid system is more than that in a sample where the QDs and the Re catalyst are simply mixed, suggesting that the covalent linkage between the CuInS2 QDs and the Re catalyst indeed facilitates electron transfer from the QDs to the Re catalyst. Such an ultrafast electron transfer in the covalently linked CuInS2 QD-Re hybrid system leads to enhanced photocatalytic activity for CO2 reduction, as compared to the conventional mixture of the QDs and the Re catalyst.

National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-363108 (URN)10.1039/c8dt01631c (DOI)000441151700051 ()30019727 (PubMedID)
Funder
Swedish Research CouncilSwedish Energy AgencyGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of TechnologyStiftelsen Olle Engkvist Byggmästare
Available from: 2018-10-15 Created: 2018-10-15 Last updated: 2018-10-15Bibliographically approved
Xu, P., Liu, P., Li, Y., Xu, B., Kloo, L., Sun, L. & Hua, Y. (2018). D-A-D-Typed Hole Transport Materials for Efficient Perovskite Solar Cells: Tuning Photovoltaic Properties via the Acceptor Group. ACS Applied Materials and Interfaces, 10(23), 19697-19703
Open this publication in new window or tab >>D-A-D-Typed Hole Transport Materials for Efficient Perovskite Solar Cells: Tuning Photovoltaic Properties via the Acceptor Group
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2018 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 23, p. 19697-19703Article in journal (Refereed) Published
Abstract [en]

Two D-A-D-structured hole-transport materials (YN1 and YN2) have been synthesized and used in perovskite solar cells. The two HTMs have low-lying HOMO levels and impressive mobility. Perovskite-based solar cells (PSCs) fabricated with YN2 showed a power conversion efficiency (PCE) value of 19.27% in ambient air, which is significantly higher than that of Spiro-OMeTAD (17.80%). PSCs based on YN1 showed an inferior PCE of 16.03%. We found that the incorporation of the stronger electron-withdrawing group in the HTM YN2 improves the PCE of PSCs. Furthermore, the YN2-based PSCs exhibit good long-term stability retaining 91.3% of its initial efficiency, whereas PSCs based on Spiro-OMeTAD retained only 42.2% after 1000 h lifetime (dark conditions). These promising results can provide a new strategy for the design of D-A-D HTMs for PSC applications in future.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
Keywords
perovskite solar cells, hole-transport material, mobility, spiro-OMeTAD, acceptor
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-358522 (URN)10.1021/acsami.8b04003 (DOI)000435525100045 ()29785846 (PubMedID)
Funder
Swedish Research CouncilSwedish Energy AgencyKnut and Alice Wallenberg Foundation
Available from: 2018-09-03 Created: 2018-09-03 Last updated: 2018-09-03Bibliographically approved
Wang, L., Zhang, J., Liu, P., Xu, B., Zhang, B., Chen, H., . . . Sun, L. (2018). Design and synthesis of dopant-free organic hole-transport materials for perovskite solar cells. Chemical Communications, 54(69), 9571-9574
Open this publication in new window or tab >>Design and synthesis of dopant-free organic hole-transport materials for perovskite solar cells
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2018 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 54, no 69, p. 9571-9574Article in journal (Refereed) Published
Abstract [en]

Two novel dopant-free hole-transport materials (HTMs) with spiro[dibenzo[c,h]xanthene-7,9-fluorene] (SDBXF) skeletons were prepared via facile synthesis routes. A power conversion efficiency of 15.9% in perovskite solar cells is attained by using one HTM without dopants, which is much higher than undoped Spiro-OMeTAD-based devices (10.8%). The crystal structures of both new HTMs were systematically investigated to reveal the reasons behind such differences in performance and to indicate the design principles of more advanced HTMs.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2018
National Category
Materials Chemistry Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-362101 (URN)10.1039/c8cc04026e (DOI)000442605100002 ()30043013 (PubMedID)
Available from: 2018-10-01 Created: 2018-10-01 Last updated: 2018-10-01Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-2913-514X

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