{"entity": "researcher", "timestamp": "2026-06-08T06:00:42.126Z", "family": "Kazimierczuk", "given": "Krzysztof", "initials": "K", "orcid": "0000-0001-9585-1737", "affiliations": ["Centre of New Technologies, University of Warsaw", "02-097 Warsaw", "Poland"], "links": {"self": {"href": "https://publications.scilifelab.se/researcher/ad35e5f050384e6c94bc2d06066a1cf6.json"}, "display": {"href": "https://publications.scilifelab.se/researcher/ad35e5f050384e6c94bc2d06066a1cf6"}}, "publications": [{"entity": "publication", "iuid": "f80e1285b68f47c18efbc1e418f337a7", "links": {"self": {"href": "https://publications.scilifelab.se/publication/f80e1285b68f47c18efbc1e418f337a7.json"}, "display": {"href": "https://publications.scilifelab.se/publication/f80e1285b68f47c18efbc1e418f337a7"}}, "title": "Clustered sparsity and Poisson-gap sampling.", "authors": [{"family": "Kasprzak", "given": "Pawe\u0142", "initials": "P"}, {"family": "Urba\u0144czyk", "given": "Mateusz", "initials": "M"}, {"family": "Kazimierczuk", "given": "Krzysztof", "initials": "K", "orcid": "0000-0001-9585-1737", "researcher": {"href": "https://publications.scilifelab.se/researcher/ad35e5f050384e6c94bc2d06066a1cf6.json"}}], "type": "journal article", "published": "2021-12-00", "journal": {"title": "J. Biomol. NMR", "issn": "1573-5001", "volume": "75", "issue": "10-12", "pages": "401-416", "issn-l": "0925-2738"}, "abstract": "Non-uniform sampling (NUS) is a popular way of reducing the amount of time taken by multidimensional NMR experiments. Among the various non-uniform sampling schemes that exist, the Poisson-gap (PG) schedules are particularly popular, especially when combined with compressed-sensing (CS) reconstruction of missing data points. However, the use of PG is based mainly on practical experience and has not, as yet, been explained in terms of CS theory. Moreover, an apparent contradiction exists between the reported effectiveness of PG and CS theory, which states that a \"flat\" pseudo-random generator is the best way to generate sampling schedules in order to reconstruct sparse spectra. In this paper we explain how, and in what situations, PG reveals its superior features in NMR spectroscopy. We support our theoretical considerations with simulations and analyses of experimental data from the Biological Magnetic Resonance Bank (BMRB). Our analyses reveal a previously unnoticed feature of many NMR spectra that explains the success of \"blue-noise\" schedules, such as PG. We call this feature \"clustered sparsity\". This refers to the fact that the peaks in NMR spectra are not just sparse but often form clusters in the indirect dimension, and PG is particularly suited to deal with such situations. Additionally, we discuss why denser sampling in the initial and final parts of the clustered signal may be useful.", "doi": "10.1007/s10858-021-00385-7", "pmid": "34739685", "labels": {"Swedish NMR Centre": "Service"}, "xrefs": [{"db": "pii", "key": "10.1007/s10858-021-00385-7"}], "notes": [], "created": "2021-12-08T15:51:43.736Z", "modified": "2025-10-17T13:03:55.293Z"}, {"entity": "publication", "iuid": "ed9dfb96ce7b4525960909d2a2186e16", "links": {"self": {"href": "https://publications.scilifelab.se/publication/ed9dfb96ce7b4525960909d2a2186e16.json"}, "display": {"href": "https://publications.scilifelab.se/publication/ed9dfb96ce7b4525960909d2a2186e16"}}, "title": "Resolution enhancement in NMR spectra by deconvolution with compressed sensing reconstruction.", "authors": [{"family": "Kazimierczuk", "given": "Krzysztof", "initials": "K", "orcid": "0000-0001-9585-1737", "researcher": {"href": "https://publications.scilifelab.se/researcher/ad35e5f050384e6c94bc2d06066a1cf6.json"}}, {"family": "Kasprzak", "given": "Pawe\u0142", "initials": "P", "orcid": "0000-0001-7387-4284", "researcher": {"href": "https://publications.scilifelab.se/researcher/aa6e68d3b1d442efb5418ee75f8f54d0.json"}}, {"family": "Georgoulia", "given": "Panagiota S", "initials": "PS", "orcid": "0000-0003-4573-8052", "researcher": {"href": "https://publications.scilifelab.se/researcher/419e2b2c66404881b3e7a51dbd47fcdb.json"}}, {"family": "Mate\u010dko-Burmann", "given": "Irena", "initials": "I", "orcid": "0000-0001-8873-8381", "researcher": {"href": "https://publications.scilifelab.se/researcher/b8f4fca92f6143aea4378e5e081339ca.json"}}, {"family": "Burmann", "given": "Bj\u00f6rn M", "initials": "BM", "orcid": "0000-0002-3135-7964", "researcher": {"href": "https://publications.scilifelab.se/researcher/b7a6d61fc1a64677874973c3247b1eb4.json"}}, {"family": "Isaksson", "given": "Linn\u00e9a", "initials": "L"}, {"family": "Gustavsson", "given": "Emil", "initials": "E", "orcid": "0000-0003-0166-1786", "researcher": {"href": "https://publications.scilifelab.se/researcher/474b967a7726414288142c12b7b9dc3f.json"}}, {"family": "Westenhoff", "given": "Sebastian", "initials": "S", "orcid": "0000-0002-6961-8015", "researcher": {"href": "https://publications.scilifelab.se/researcher/3f1519bb234b43c6a13833b04e6720b8.json"}}, {"family": "Orekhov", "given": "Vladislav Yu", "initials": "VY", "orcid": "0000-0002-7892-6896", "researcher": {"href": "https://publications.scilifelab.se/researcher/77382c412de04fa08ff7c3bc7087b77e.json"}}], "type": "journal article", "published": "2020-12-04", "journal": {"title": "Chem. Commun. (Camb.)", "issn": "1364-548X", "volume": "56", "issue": "93", "pages": "14585-14588", "issn-l": "1359-7345"}, "abstract": "NMR spectroscopy is one of the basic tools for molecular structure elucidation. Unfortunately, the resolution of the spectra is often limited by inter-nuclear couplings. The existing workarounds often alleviate the problem by trading it for another deficiency, such as spectral artefacts or difficult sample preparation and, thus, are rarely used. We suggest an approach using the coupling deconvolution in the framework of compressed sensing (CS) spectra processing that leads to a major increase in resolution, sensitivity, and overall quality of NUS reconstruction. A new mathematical description of the decoupling by deconvolution explains the effects of thermal noise and reveals a relation with the underlying assumption of the CS. The gain in resolution and sensitivity for challenging molecular systems is demonstrated for the key HNCA experiment used for protein backbone assignment applied to two large proteins: intrinsically disordered 441-residue Tau and a 509-residue globular bacteriophytochrome fragment. The approach will be valuable in a multitude of chemistry applications, where NMR experiments are compromised by the homonuclear scalar coupling.", "doi": "10.1039/d0cc06188c", "pmid": "33146166", "labels": {"Swedish NMR Centre": "Collaborative"}, "xrefs": [], "notes": [], "created": "2020-12-11T09:16:11.124Z", "modified": "2025-10-17T13:03:56.405Z"}]}