TY  - JOUR
A1  - Budiman, Yudha P.
A1  - Lorenzen, Sabine
A1  - Liu, Zhiqiang
A1  - Radius, Udo
A1  - Marder, Todd B.
T1  - Base‐Free Pd‐Catalyzed C−Cl Borylation of Fluorinated Aryl Chlorides
JF  - Chemistry – A European Journal
N2  - Catalytic C−X borylation of aryl halides containing two ortho‐fluorines has been found to be challenging, as most previous methods require stoichiometric amounts of base and the polyfluorinated aryl boronates suffer from protodeboronation, which is accelerated by ortho‐fluorine substituents. Herein, we report that a combination of Pd(dba)2 (dba=dibenzylideneacetone) with SPhos (2‐dicyclohexylphosphino‐2’,6’‐dimethoxybiphenyl) as a ligand is efficient to catalyze the C‐Cl borylation of aryl chlorides containing two ortho‐fluorine substituents. This method, conducted under base‐free conditions, is compatible with the resulting di‐ortho‐fluorinated aryl boronate products which are sensitive to base.
KW  - boronate ester
KW  - borylation
KW  - cross-coupling
KW  - fluoroarene
KW  - palladium-catalyzed
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225687
VL  - 27
IS  - 11
SP  - 3869
EP  - 3874
ER  - 
TY  - JOUR
A1  - Weich, Alexander
A1  - Werner, Rudolf A.
A1  - Buck, Andreas K.
A1  - Hartrampf, Philipp E.
A1  - Serfling, Sebastian E.
A1  - Scheurlen, Michael
A1  - Wester, Hans-Jürgen
A1  - Meining, Alexander
A1  - Kircher, Stefan
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
A1  - Kircher, Malte
T1  - CXCR4-Directed PET/CT in Patients with Newly Diagnosed Neuroendocrine Carcinomas
JF  - Diagnostics
N2  - We aimed to elucidate the diagnostic potential of the C-X-C motif chemokine receptor 4 (CXCR4)-directed positron emission tomography (PET) tracer \(^{68}\)Ga-Pentixafor in patients with poorly differentiated neuroendocrine carcinomas (NEC), relative to the established reference standard \(^{18}\)F-FDG PET/computed tomography (CT). In our database, we retrospectively identified 11 treatment-naïve patients with histologically proven NEC, who underwent \(^{18}\)F-FDG and CXCR4-directed PET/CT for staging and therapy planning. The images were analyzed on a per-patient and per-lesion basis and compared to immunohistochemical staining (IHC) of CXCR4 from PET-guided biopsies. \(^{68}\)Ga-Pentixafor visualized tumor lesions in 10/11 subjects, while \(^{18}\)F-FDG revealed sites of disease in all 11 patients. Although weak to moderate CXCR4 expression could be corroborated by IHC in 10/11 cases, \(^{18}\)F-FDG PET/CT detected significantly more tumor lesions (102 vs. 42; total lesions, n = 107; p < 0.001). Semi-quantitative analysis revealed markedly higher 18F-FDG uptake as compared to \(^{68}\)Ga-Pentixafor (maximum and mean standardized uptake values (SUV) and tumor-to-background ratios (TBR) of cancerous lesions, SUVmax: 12.8 ± 9.8 vs. 5.2 ± 3.7; SUVmean: 7.4 ± 5.4 vs. 3.1 ± 3.2, p < 0.001; and, TBR 7.2 ± 7.9 vs. 3.4 ± 3.0, p < 0.001). Non-invasive imaging of CXCR4 expression in NEC is inferior to the reference standard \(^{18}\)F-FDG PET/CT.
KW  - CXCR4
KW  - NET
KW  - NEC
KW  - <sup>68</sup>Ga-Pentixafor
KW  - <sup>18</sup>F-FDG
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234231
SN  - 2075-4418
VL  - 11
IS  - 4
ER  - 
TY  - JOUR
A1  - Mönius, Katja
T1  - Eigenvalues of zero-divisor graphs of finite commutative rings
JF  - Journal of Algebraic Combinatorics
N2  - We investigate eigenvalues of the zero-divisor graph Γ(R) of finite commutative rings R and study the interplay between these eigenvalues, the ring-theoretic properties of R and the graph-theoretic properties of Γ(R). The graph Γ(R) is defined as the graph with vertex set consisting of all nonzero zero-divisors of R and adjacent vertices x, y whenever xy=0. We provide formulas for the nullity of Γ(R), i.e., the multiplicity of the eigenvalue 0 of Γ(R). Moreover, we precisely determine the spectra of \(\Gamma ({\mathbb {Z}}_p \times {\mathbb {Z}}_p \times {\mathbb {Z}}_p)\) and \(\Gamma ({\mathbb {Z}}_p \times {\mathbb {Z}}_p \times {\mathbb {Z}}_p \times {\mathbb {Z}}_p)\) for a prime number p. We introduce a graph product ×Γ with the property that Γ(R)≅Γ(R\(_1\))×Γ⋯×ΓΓ(R\(_r\)) whenever R≅R\(_1\)×⋯×R\(_r\). With this product, we find relations between the number of vertices of the zero-divisor graph Γ(R), the compressed zero-divisor graph, the structure of the ring R and the eigenvalues of Γ(R).
KW  - EJMA-D-19-00287
KW  - Zero-divisor graphs
KW  - Graph eigenvalues
KW  - Graphnullity
KW  - Graph products
KW  - Local rings
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232792
SN  - 0925-9899
VL  - 54
ER  - 
TY  - JOUR
A1  - Grob, Robin
A1  - Tritscher, Clara
A1  - Grübel, Kornelia
A1  - Stigloher, Christian
A1  - Groh, Claudia
A1  - Fleischmann, Pauline N.
A1  - Rössler, Wolfgang
T1  - Johnston's organ and its central projections in Cataglyphis desert ants
JF  - Journal of Comparative Neurology
N2  - The Johnston's organ (JO) in the insect antenna is a multisensory organ involved in several navigational tasks including wind‐compass orientation, flight control, graviception, and, possibly, magnetoreception. Here we investigate the three dimensional anatomy of the JO and its neuronal projections into the brain of the desert ant Cataglyphis, a marvelous long‐distance navigator. The JO of C. nodus workers consists of 40 scolopidia comprising three sensory neurons each. The numbers of scolopidia slightly vary between different sexes (female/male) and castes (worker/queen). Individual scolopidia attach to the intersegmental membrane between pedicel and flagellum of the antenna and line up in a ring‐like organization. Three JO nerves project along the two antennal nerve branches into the brain. Anterograde double staining of the antennal afferents revealed that JO receptor neurons project to several distinct neuropils in the central brain. The T5 tract projects into the antennal mechanosensory and motor center (AMMC), while the T6 tract bypasses the AMMC via the saddle and forms collaterals terminating in the posterior slope (PS) (T6I), the ventral complex (T6II), and the ventrolateral protocerebrum (T6III). Double labeling of JO and ocellar afferents revealed that input from the JO and visual information from the ocelli converge in tight apposition in the PS. The general JO anatomy and its central projection patterns resemble situations in honeybees and Drosophila. The multisensory nature of the JO together with its projections to multisensory neuropils in the ant brain likely serves synchronization and calibration of different sensory modalities during the ontogeny of navigation in Cataglyphis.
KW  - ant brain
KW  - chordotonal organ
KW  - graviception
KW  - magnetic compass
KW  - multisensory integration
KW  - navigation
KW  - wind compass
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225679
VL  - 529
IS  - 8
SP  - 2138
EP  - 2155
ER  - 
TY  - JOUR
A1  - Full, Julian
A1  - Panchal, Santosh P.
A1  - Götz, Julian
A1  - Krause, Ana‐Maria
A1  - Nowak‐Król, Agnieszka
T1  - Modular Synthesis of Organoboron Helically Chiral Compounds: Cutouts from Extended Helices
JF  - Angewandte Chemie International Edition
N2  - Two types of helically chiral compounds bearing one and two boron atoms were synthesized by a modular approach. Formation of the helical scaffolds was executed by the introduction of boron to flexible biaryl and triaryl derived from small achiral building blocks. All‐ortho‐fused azabora[7]helicenes feature exceptional configurational stability, blue or green fluorescence with quantum yields (Φ\(_{fl}\)) of 18–24 % in solution, green or yellow solid‐state emission (Φ\(_{fl}\) up to 23 %), and strong chiroptical response with large dissymmetry factors of up to 1.12×10\(^{-2}\). Azabora[9]helicenes consisting of angularly and linearly fused rings are blue emitters exhibiting Φ\(_{fl}\) of up to 47 % in CH\(_{2}\)Cl\(_{2}\) and 25 % in the solid state. As revealed by the DFT calculations, their P–M interconversion pathway is more complex than that of H1. Single‐crystal X‐ray analysis shows clear differences in the packing arrangement of methyl and phenyl derivatives. These molecules are proposed as primary structures of extended helices.
KW  - chirality
KW  - circular dichroism
KW  - fluorescence
KW  - helicene
KW  - organoboron
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225775
VL  - 60
IS  - 8
SP  - 4350
EP  - 4357
ER  - 
TY  - JOUR
A1  - Urlaub, Jonas
A1  - Kaiser, Reinhard P.
A1  - Scherf‐Clavel, Oliver
A1  - Bolm, Carsten
A1  - Holzgrabe, Ulrike
T1  - Investigation of isomerization of dexibuprofen in a ball mill using chiral capillary electrophoresis
JF  - Electrophoresis
N2  - Besides the racemate, the S‐enantiomer of ibuprofen (Ibu) is used for the treatment of inflammation and pain. Since the configurational stability of S‐Ibu in solid state is of interest, it was studied by means of ball milling experiments. For the evaluation of the enantiomeric composition, a chiral CE method was developed and validated according to the ICH guideline Q2(R1). The addition of Mg\(^{2+}\), Ca\(^{2+}\), or Zn\(^{2+}\) ions to the background electrolyte (BGE) was found to improve Ibu enantioresolution. Chiral separation of Ibu enantiomers was achieved on a 60.2 cm (50.0 cm effective length) x 75 μm fused‐silica capillary using a background electrolyte (BGE) composed of 50 mM sodium acetate, 10 mM magnesium acetate tetrahydrate, and 35 mM heptakis‐(2,3,6‐tri‐O‐methyl)‐β‐cyclodextrin (TM‐β‐CD) as chiral selector. The quantification of R‐Ibu in the mixture was performed using the normalization procedure. Linearity was evaluated in the range of 0.68–5.49% R‐Ibu (R\(^{2}\) = 0.999), recovery was found to range between 97 and 103%, the RSD of intra‐ and interday precision below 2.5%, and the limit of quantification for R‐ in S‐Ibu was calculated to be 0.21% (extrapolated) and 0.15% (dilution of racemic ibuprofen), respectively. Isomerization of S‐Ibu was observed under basic conditions by applying long milling times and high milling frequencies.
KW  - capillary electrophoresis
KW  - chiral separation
KW  - Ibuprofen
KW  - isomerization
KW  - validation
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225852
VL  - 42
IS  - 17-18
SP  - 1790
EP  - 1799
ER  - 
TY  - JOUR
A1  - Zahoranová, Anna
A1  - Luxenhofer, Robert
T1  - Poly(2‐oxazoline)‐ and Poly(2‐oxazine)‐Based Self‐Assemblies, Polyplexes, and Drug Nanoformulations—An Update
JF  - Advanced Healthcare Materials
N2  - For many decades, poly(2‐oxazoline)s and poly(2‐oxazine)s, two closely related families of polymers, have led the life of a rather obscure research topic with only a few research groups world‐wide working with them. This has changed in the last five to ten years, presumably triggered significantly by very promising clinical trials of the first poly(2‐oxazoline)‐based drug conjugate. The huge chemical and structural toolbox poly(2‐oxazoline)s and poly(2‐oxazine)s has been extended very significantly in the last few years, but their potential still remains largely untapped. Here, specifically, the developments in macromolecular self‐assemblies and non‐covalent drug delivery systems such as polyplexes and drug nanoformulations based on poly(2‐oxazoline)s and poly(2‐oxazine)s are reviewed. This highly dynamic field benefits particularly from the extensive synthetic toolbox poly(2‐oxazoline)s and poly(2‐oxazine)s offer and also may have the largest potential for a further development. It is expected that the research dynamics will remain high in the next few years, particularly as more about the safety and therapeutic potential of poly(2‐oxazoline)s and poly(2‐oxazine)s is learned.
KW  - block copolymers
KW  - colloids
KW  - cytotoxicity
KW  - drug delivery
KW  - micelles
KW  - microphase separation
KW  - thermogelling
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225833
VL  - 10
IS  - 6
ER  - 
TY  - JOUR
A1  - Hojsgaard, Diego
A1  - Schartl, Manfred
T1  - Skipping sex: A nonrecombinant genomic assemblage of complementary reproductive modules
JF  - BioEssays
N2  - The unusual occurrence and developmental diversity of asexual eukaryotes remain a puzzle. De novo formation of a functioning asexual genome requires a unique assembly of sets of genes or gene states to disrupt cellular mechanisms of meiosis and gametogenesis, and to affect discrete components of sexuality and produce clonal or hemiclonal offspring. We highlight two usually overlooked but essential conditions to understand the molecular nature of clonal organisms, that is, a nonrecombinant genomic assemblage retaining modifiers of the sexual program, and a complementation between altered reproductive components. These subtle conditions are the basis for physiologically viable and genetically balanced transitions between generations. Genomic and developmental evidence from asexual animals and plants indicates the lack of complementation of molecular changes in the sexual reproductive program is likely the main cause of asexuals' rarity, and can provide an explanatory frame for the developmental diversity and lability of developmental patterns in some asexuals as well as for the discordant time to extinction estimations.
KW  - amphimixis
KW  - apomixis
KW  - automixis
KW  - gynogenesis
KW  - hybridogenesis
KW  - parthenogenesis
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225818
VL  - 43
IS  - 1
ER  - 
TY  - JOUR
A1  - Budiman, Yudha P.
A1  - Westcott, Stephen A.
A1  - Radius, Udo
A1  - Marder, Todd B.
T1  - Fluorinated Aryl Boronates as Building Blocks in Organic Synthesis
JF  - Advanced Synthesis & Catalysis
N2  - Organoboron compounds are well known building blocks for many organic reactions. However, under basic conditions, polyfluorinated aryl boronic acid derivatives suffer from instability issues that are accelerated in compounds containing an ortho‐fluorine group, which result in the formation of the corresponding protodeboronation products. Therefore, a considerable amount of research has focused on novel methodologies to synthesize these valuable compounds while avoiding the protodeboronation issue. This review summarizes the latest developments in the synthesis of fluorinated aryl boronic acid derivatives and their applications in cross‐coupling reactions and other transformations.

image
KW  - homogeneous catalysis
KW  - boron reagents
KW  - boronates
KW  - fluorine
KW  - fluoroarene
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225908
VL  - 363
IS  - 9
SP  - 2224
EP  - 2255
ER  - 
TY  - JOUR
A1  - Ravat, Prince
T1  - Carbo[n]helicenes Restricted to Enantiomerize: An Insight into the Design Process of Configurationally Stable Functional Chiral PAHs
JF  - Chemistry – A European Journal
N2  - The most important stereodynamic feature of carbo[n]helicenes is the interconversion of their enantiomers. The Gibbs activation energy (ΔG≠(T)) of this process, which determines the rate of enantiomerization, dictates the configurational stability of [n]helicenes. High values of ΔG≠(T) are required for applications of functional chiral molecules incorporating [n]helicenes or helicene substructures. This minireview provides an overview of the mechanism, recent developments, and factors affecting the enantiomerization of [n]helicenes, which will accelerate the design process of configurationally stable functional chiral molecules based on helicene substructures. Additionally, this minireview addresses the misconception and irregularities in the recent literature on how the terms “racemization” and “enantiomerization” are used as well as how the activation parameters are calculated for [n]helicenes and related compounds.
KW  - [n]helicenes
KW  - configurational stability
KW  - enantiomerization
KW  - Gibbs activation energy
KW  - racemization
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225871
VL  - 27
IS  - 12
SP  - 3957
EP  - 3967
ER  - 
TY  - JOUR
A1  - Sprenger, Philipp P.
A1  - Müsse, Christian
A1  - Hartke, Juliane
A1  - Feldmeyer, Barbara
A1  - Schmitt, Thomas
A1  - Gebauer, Gerhard
A1  - Menzel, Florian
T1  - Dinner with the roommates: trophic niche differentiation and competition in a mutualistic ant‐ant association
JF  - Ecological Entomology
N2  - 1. The potential for competition is highest among species in close association. Despite net benefits for both parties, mutualisms can involve costs, including food competition. This might be true for the two neotropical ants Camponotus femoratus and Crematogaster levior, which share the same nest in a presumably mutualistic association (parabiosis).
2. While each nest involves one Crematogaster and one Camponotus partner, both taxa were recently found to comprise two cryptic species that show no partner preferences and seem ecologically similar. Since these cryptic species often occur in close sympatry, they might need to partition their niches to avoid competitive exclusion.
3. Here, we investigated first, is there interference competition between parabiotic Camponotus and Crematogaster, and do they prefer different food sources under competition? And second, is there trophic niche partitioning between the cryptic species of either genus?
4. Using cafeteria experiments, neutral lipid fatty acid and stable isotope analyses, we found evidence for interference competition, but also trophic niche partitioning between Camponotus and Crematogaster. Both preferred protein‐ and carbohydrate‐rich baits, but at protein‐rich baits Ca. femoratus displaced Cr. levior over time, suggesting a potential discovery‐dominance trade‐off between parabiotic partners. Only limited evidence was found for trophic differentiation between the cryptic species of each genus.
5. Although we cannot exclude differentiation in other niche dimensions, we argue that neutral dynamics might mediate the coexistence of cryptic species. This model system is highly suitable for further studies of the maintenance of species diversity and the role of mutualisms in promoting species coexistence.
KW  - Cryptic species
KW  - Formicidae
KW  - neutral theory
KW  - niche partitioning
KW  - nutrition
KW  - parabiosis
KW  - species coexistence mechanism
KW  - trade‐offs
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228215
VL  - 46
IS  - 3
SP  - 562
EP  - 572
ER  - 
TY  - JOUR
A1  - Du, Baoguo
A1  - Ma, Yuhua
A1  - Yáñez‐Serrano, Ana Maria
A1  - Arab, Leila
A1  - Fasbender, Lukas
A1  - Alfarraj, Saleh
A1  - Albasher, Gadah
A1  - Hedrich, Rainer
A1  - White, Philip J.
A1  - Werner, Christiane
A1  - Rennenberg, Heinz
T1  - Physiological responses of date palm (Phoenix dactylifera) seedlings to seawater and flooding
JF  - New Phytologist
N2  - In their natural environment along coast lines, date palms are exposed to seawater inundation and, hence, combined stress by salinity and flooding.

To elucidate the consequences of this combined stress on foliar gas exchange and metabolite abundances in leaves and roots, date palm seedlings were exposed to flooding with seawater and its major constituents under controlled conditions.

Seawater flooding significantly reduced CO\(_{2}\) assimilation, transpiration and stomatal conductance, but did not affect isoprene emission. A similar effect was observed upon NaCl exposure. By contrast, flooding with distilled water or MgSO\(_{4}\) did not affect CO\(_{2}\)/H\(_{2}\)O gas exchange or stomatal conductance significantly, indicating that neither flooding itself, nor seawater sulfate, contributed greatly to stomatal closure. Seawater exposure increased Na and Cl contents in leaves and roots, but did not affect sulfate contents significantly. Metabolite analyses revealed reduced abundances of foliar compatible solutes, such as sugars and sugar alcohols, whereas nitrogen compounds accumulated in roots.

Reduced transpiration upon seawater exposure may contribute to controlling the movement of toxic ions to leaves and, therefore, can be seen as a mechanism to cope with salinity. The present results indicate that date palm seedlings are tolerant towards seawater exposure to some extent, and highly tolerant to flooding.
KW  - compatible solutes and other metabolites
KW  - date palm
KW  - flooding
KW  - salinity
KW  - shoot–root interaction
KW  - stomatal conductance
KW  - sulfate
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228226
VL  - 229
IS  - 6
SP  - 3318
EP  - 3329
ER  - 
TY  - JOUR
A1  - Seibold, Sebastian
A1  - Hothorn, Torsten
A1  - Gossner, Martin M.
A1  - Simons, Nadja K.
A1  - Blüthgen, Nico
A1  - Müller, Jörg
A1  - Ambarlı, Didem
A1  - Ammer, Christian
A1  - Bauhus, Jürgen
A1  - Fischer, Markus
A1  - Habel, Jan C.
A1  - Penone, Caterina
A1  - Schall, Peter
A1  - Schulze, Ernst‐Detlef
A1  - Weisser, Wolfgang W.
T1  - Insights from regional and short‐term biodiversity monitoring datasets are valuable: a reply to Daskalova et al. 2021
JF  - Insect Conservation and Diversity
N2  - Reports of major losses in insect biodiversity have stimulated an increasing interest in temporal population changes. Existing datasets are often limited to a small number of study sites, few points in time, a narrow range of land‐use intensities and only some taxonomic groups, or they lack standardised sampling. While new monitoring programs have been initiated, they still cover rather short time periods.
Daskalova et al. 2021 (Insect Conservation and Diversity, 14, 1‐18) argue that temporal trends of insect populations derived from short time series are biased towards extreme trends, while their own analysis of an assembly of shorter‐ and longer‐term time series does not support an overall insect decline. With respect to the results of Seibold et al. 2019 (Nature, 574, 671–674) based on a 10‐year multi‐site time series, they claim that the analysis suffers from not accounting for temporal pseudoreplication.
Here, we explain why the criticism of missing statistical rigour in the analysis of Seibold et al. (2019) is not warranted. Models that include ‘year’ as random effect, as suggested by Daskalova et al. (2021), fail to detect non‐linear trends and assume that consecutive years are independent samples which is questionable for insect time‐series data.
We agree with Daskalova et al. (2021) that the assembly and analysis of larger datasets is urgently needed, but it will take time until such datasets are available. Thus, short‐term datasets are highly valuable, should be extended and analysed continually to provide a more detailed understanding of insect population changes under the influence of global change, and to trigger immediate conservation actions.
KW  - Arthropod
KW  - biodiversity
KW  - insect decline
KW  - land use
KW  - time series
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228309
VL  - 14
IS  - 1
SP  - 144
EP  - 148
ER  - 
TY  - JOUR
A1  - Rosenfeldt, Mathias T.
A1  - Hartmann, Elena M.
A1  - Leng, Corinna
A1  - Rosenwald, Andreas
A1  - Anagnostopoulos, Ioannis
T1  - A case of nodular lymphocyte predominant Hodgkin lymphoma with unexpected EBV-latency type
JF  - Annals of Hematology
N2  - No abstract available.
KW  - nodular lymphcyte
KW  - Hodgkin lymphoma
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232571
SN  - 0939-5555
VL  - 100
ER  - 
TY  - JOUR
A1  - Höhn, Stefan
A1  - Frimmel, Hartwig E.
A1  - Debaille, Vinciane
A1  - Price, Westley
T1  - Pre‐Klondikean oxidation prepared the ground for Broken Hill‐type mineralization in South Africa
JF  - Terra Nova
N2  - New Cu isotope data obtained on chalcopyrite from the Black Mountain and the Broken Hill deposits in the medium‐ to high‐grade metamorphic Aggeneys‐Gamsberg ore district (South Africa) require a revision of our understanding of the genesis of metamorphic Broken Hill‐type massive sulphide deposits. Chalcopyrite from both deposits revealed unusually wide ranges in δ\(^{65}\)Cu (−2.41 to 2.84‰ NIST 976 standard) in combination with distinctly positive mean values (0.27 and 0.94‰, respectively). This is interpreted to reflect derivation from various silicate and oxide precursor minerals in which Cu occurred in higher oxidation states. Together with the observation of a typical supergene base metal distribution within the deposits and their spatial association with an unconformity only meters above the ore horizon, our new data are best explained by supergene oxidation of originally possibly SEDEX deposits prior to metamorphic sulphide formation, between the Okiepian (1,210–1,180 Ma) and Klondikean (1,040–1,020 Ma) orogenic events.
KW  - South Africa
KW  - mineralization
KW  - Broken Hill
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218545
VL  - 33
IS  - 2
SP  - 168
EP  - 173
ER  - 
TY  - JOUR
A1  - Almeida, R.
A1  - Hristova, S.
A1  - Dashkovskiy, S.
T1  - Uniform bounded input bounded output stability of fractional‐order delay nonlinear systems with input
JF  - International Journal of Robust and Nonlinear Control
N2  - The bounded input bounded output (BIBO) stability for a nonlinear Caputo fractional system with time‐varying bounded delay and nonlinear output is studied. Utilizing the Razumikhin method, Lyapunov functions and appropriate fractional derivatives of Lyapunov functions some new bounded input bounded output stability criteria are derived. Also, explicit and independent on the initial time bounds of the output are provided. Uniform BIBO stability and uniform BIBO stability with input threshold are studied. A numerical simulation is carried out to show the system's dynamic response, and demonstrate the effectiveness of our theoretical results.
KW  - bounded input bounded output stability
KW  - Caputo fractional derivative
KW  - Lyapunov functions
KW  - Razumikhin method
KW  - time‐varying delay
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218554
VL  - 31
IS  - 1
SP  - 225
EP  - 249
ER  - 
TY  - JOUR
A1  - Wolf, Matthias
T1  - How to teach about what is a species
JF  - Biology
N2  - To ask students what a species is always has something rhetorical about it. Too quickly comes the rote answer, often learned by heart without ever thinking about it: “A species is a reproductive community of populations (reproductively isolated from others), which occupies a specific niche in nature” (Mayr 1982). However, do two people look alike because they are twins or are they twins because they look alike? “Two organisms do not belong to the same species because they mate and reproduce, but they only are able to do so because they belong to the same species” (Mahner and Bunge 1997). Unfortunately, most biology (pre-university) teachers have no opinion on whether species are real or conceptual, simply because they have never been taught the question themselves, but rather one answer they still pass on to their students today, learned by heart without ever thinking about it. Species are either real or conceptual and, in my opinion, it is this “or” that we should teach about. Only then can we discuss those fundamental questions such as who or what is selected, who or what evolves and, finally, what is biodiversity and phylogenetics all about? Individuals related to each other by the tree of life.
KW  - biospecies
KW  - species as individuals
KW  - species as natural kinds
KW  - species concept
KW  - species problem
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241052
SN  - 2079-7737
VL  - 10
IS  - 6
ER  - 
TY  - JOUR
A1  - Gerner, Bettina
A1  - Scherf-Clavel, Oliver
T1  - Physiologically based pharmacokinetic modelling of Cabozantinib to simulate enterohepatic recirculation, drug−drug interaction with Rifampin and liver impairment
JF  - Pharmaceutics
N2  - Cabozantinib (CAB) is a receptor tyrosine kinase inhibitor approved for the treatment of several cancer types. Enterohepatic recirculation (EHC) of the substance is assumed but has not been further investigated yet. CAB is mainly metabolized via CYP3A4 and is susceptible for drug–drug interactions (DDI). The goal of this work was to develop a physiologically based pharmacokinetic (PBPK) model to investigate EHC, to simulate DDI with Rifampin and to simulate subjects with hepatic impairment. The model was established using PK-Sim® and six human clinical studies. The inclusion of an EHC process into the model led to the most accurate description of the pharmacokinetic behavior of CAB. The model was able to predict plasma concentrations with low bias and good precision. Ninety-seven percent of all simulated plasma concentrations fell within 2-fold of the corresponding concentration observed. Maximum plasma concentration (C\(_{max}\)) and area under the curve (AUC) were predicted correctly (predicted/observed ratio of 0.9–1.2 for AUC and 0.8–1.1 for C\(_{max}\)). DDI with Rifampin led to a reduction in predicted AUC by 77%. Several physiological parameters were adapted to simulate hepatic impairment correctly. This is the first CAB model used to simulate DDI with Rifampin and hepatic impairment including EHC, which can serve as a starting point for further simulations with regard to special populations.
KW  - physiologically based pharmacokinetic (PBPK) modeling
KW  - Cabozantinib
KW  - enterohepatic recirculation
KW  - drug–drug interactions (DDIs)
KW  - liver impairment
KW  - cytochrome P450 3A4 (CYP3A4)
KW  - pharmacokinetics
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239661
SN  - 1999-4923
VL  - 13
IS  - 6
ER  - 
TY  - JOUR
A1  - Horder, Hannes
A1  - Guaza Lasheras, Mar
A1  - Grummel, Nadine
A1  - Nadernezhad, Ali
A1  - Herbig, Johannes
A1  - Ergün, Süleyman
A1  - Teßmar, Jörg
A1  - Groll, Jürgen
A1  - Fabry, Ben
A1  - Bauer-Kreisel, Petra
A1  - Blunk, Torsten
T1  - Bioprinting and differentiation of adipose-derived stromal cell spheroids for a 3D breast cancer-adipose tissue model
JF  - Cells
N2  - Biofabrication, including printing technologies, has emerged as a powerful approach to the design of disease models, such as in cancer research. In breast cancer, adipose tissue has been acknowledged as an important part of the tumor microenvironment favoring tumor progression. Therefore, in this study, a 3D-printed breast cancer model for facilitating investigations into cancer cell-adipocyte interaction was developed. First, we focused on the printability of human adipose-derived stromal cell (ASC) spheroids in an extrusion-based bioprinting setup and the adipogenic differentiation within printed spheroids into adipose microtissues. The printing process was optimized in terms of spheroid viability and homogeneous spheroid distribution in a hyaluronic acid-based bioink. Adipogenic differentiation after printing was demonstrated by lipid accumulation, expression of adipogenic marker genes, and an adipogenic ECM profile. Subsequently, a breast cancer cell (MDA-MB-231) compartment was printed onto the adipose tissue constructs. After nine days of co-culture, we observed a cancer cell-induced reduction of the lipid content and a remodeling of the ECM within the adipose tissues, with increased fibronectin, collagen I and collagen VI expression. Together, our data demonstrate that 3D-printed breast cancer-adipose tissue models can recapitulate important aspects of the complex cell–cell and cell–matrix interplay within the tumor-stroma microenvironment
KW  - adipose-derived stromal cells
KW  - adipose tissue
KW  - bioprinting
KW  - breast cancer model
KW  - extracellular matrix
KW  - hyaluronic acid
KW  - spheroids
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236496
VL  - 10
IS  - 4
ER  - 
TY  - JOUR
A1  - Wagner, Nicole
A1  - Mott, Kristina
A1  - Upcin, Berin
A1  - Stegner, David
A1  - Schulze, Harald
A1  - Ergün, Süleyman
T1  - CXCL12-abundant reticular (CAR) cells direct megakaryocyte protrusions across the bone marrow sinusoid wall
JF  - Cells
N2  - Megakaryocytes (MKs) release platelets into the lumen of bone marrow (BM) sinusoids while remaining to reside within the BM. The morphogenetic events of this complex process are still not fully understood. We combined confocal laser scanning microscopy with transmission and serial block-face scanning electron microscopy followed by 3D-reconstruction on mouse BM tissue sections. These analyses revealed that MKs in close vicinity to BM sinusoid (BMS) wall first induce the lateral retraction of CXCL12-abundant reticular (CAR) cells (CAR), followed by basal lamina (BL) degradation enabling direct MK-sinusoidal endothelial cells (SECs) interaction. Subsequently, an endothelial engulfment starts that contains a large MK protrusion. Then, MK protrusions penetrate the SEC, transmigrate into the BMS lumen and form proplatelets that are in direct contact to the SEC surface. Furthermore, such processes are induced on several sites, as observed by 3D reconstructions. Our data demonstrate that MKs in interaction with CAR-cells actively induce BMS wall alterations, including CAR-cell retraction, BL degradation, and SEC engulfment containing a large MK protrusion. This results in SEC penetration enabling the migration of MK protrusion into the BMS lumen where proplatelets that are adherent to the luminal SEC surface are formed and contribute to platelet release into the blood circulation.
KW  - megakaryocytes
KW  - microvasculature
KW  - CXCL12-abundant reticular (CAR)-cells
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234180
SN  - 2073-4409
VL  - 10
IS  - 4
ER  -